Head-up display apparatus

The present invention relates to a head-up display apparatus, and more particularly, to a technique that can be effectively applied to a head-up display apparatus using augmented reality (AR).

For example, for a vehicle such as an automobile, information such as a vehicle speed and a rotational speed of an engine is typically displayed on an instrument panel in a dashboard. Also, a screen of a car navigation system or the like is incorporated in the dashboard or displayed on a display set up on the dashboard. When a driver visually recognizes these pieces of information, it is required to move a line of sight largely, and thus, as a technique of reducing a movement amount of the line of sight, a head-up display (Head Up Display, hereinafter referred to as “HUD,” in some cases) which projects information such as a vehicle speed and information such as an instruction relating to a car navigation system onto a front glass (windshield) to display has been known.

In an in-vehicle display apparatus also including the HUD, since a vehicle may vibrate or incline in accordance with a running condition, a case in which visibility of a display video image may cause a problem or a case in which suitable contents cannot be displayed may be generated, in some cases.

As a technique related to improvement in visibility of a display video image in the HUD, for example, Japanese Patent Application Laid-Open Publication No. 2013-237320 (Patent Document 1) discloses that a rotational component generated in a vehicle body is acquired as an inclination of the vehicle body, a video image is rotationally corrected three-dimensionally based on this inclination, and a position and an inclination for displaying the rotationally corrected video image are decided to project and display the video image.

Also, Japanese Patent Application Laid-Open Publication No. 2007-55365 (Patent Document 2) discloses that, when a distance scale is displayed in an HUD, by acquiring information of a running point at which an own vehicle is currently running, and information of a scheduled running point at which the own vehicle will run from a map data of a navigation device, an incline angle of a road on which the own vehicle runs is acquired based on these pieces of information, and a display height of the distance scale from a ground is corrected by using a correction coefficient in accordance with the incline angle and displayed.

Also, Japanese Patent Application Laid-Open Publication No. 2006-7867 (Patent Document 3) discloses that, in accordance with a detected running condition such as a right or left turn and accelerated or decelerated speed, control is performed such that a display position of a generated video image is, for example, shifted in the left direction when the left turn is detected and shifted in the right direction when the right turn is detected.

Also, Japanese Patent Application Laid-Open Publication No. 2015-202842 (Patent Document 4) discloses that a display position of video image information is moved in a direction in which a field of view of a driver is ensured according to a vehicle state.

Patent Documents

Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2013-237320

Patent Document 2: Japanese Patent Application Laid-Open Publication No. 2007-55365

Patent Document 3: Japanese Patent Application Laid-Open Publication No. 2006-7867

Patent Document 4: Japanese Patent Application Laid-Open Publication No. 2015-202842

Problems to be Solved by the Invention

The HUD projects a video image onto a windshield, allowing a driver to recognize the video image as a virtual image outside a vehicle. In contrast, an HUD (hereinafter referred to as an “AR-HUD,” in some cases) achieving a so-called AR function capable of showing information related to an object etc. to the driver by displaying such that a virtual image is overlapped with actual scenery outside the vehicle seen through the windshield, has been known. Even in such AR-HUD, it is required to perform adjustment for maintaining visibility, suitability, and the like of a display video image, in accordance with a running condition and the like of the vehicle.

In this regard, for example, using the techniques disclosed in Patent Documents 1 to 3 above enables reduction and elimination of adverse influence on visibility and suitability of the display video image (virtual image) even in a case in which the vehicle vibrates or inclines in accordance with a running condition.

Meanwhile, these techniques perform adjustment of a display position, display contents, and the like of a video image to be displayed in a display region of the virtual image in the HUD as an object, in accordance with a running condition. However, in the case of the HUD, taking into consideration such a configuration that an effect of reducing a movement amount of a line of sight of a driver can be obtained regardless of a running condition of a vehicle, it is desirable to perform not only adjustment of the video image in the display region, but also adjustment of moving a position of the display region itself, for example.

In this regard, in the technique disclosed in Patent Document 4, it is possible to move the display region itself in the HUD in accordance with the vehicle state. However, the technique disclosed in Patent Document 4 is intended to ensure the field of view of the driver even when the vehicle state has changed and is to move the display region in the HUD to a position at which the display region does not become hindrance to the driver. Applying such technique to the AR-HUD causes a case in which a virtual image cannot be overlapped with actual scenery included in the field of view of the driver, whereby the AR function fails to have workability.

In view of this, an object of the present invention is to provide a head-up display apparatus capable of displaying a virtual image so as to be suitably overlapped with actual scenery in accordance with a running condition of a vehicle.

The above and other objects and novel features of the present invention will be apparent from the description of the present specification and the accompanying drawings.

Means to Solving the Problems

The typical ones of the inventions disclosed in the present application will be briefly described as follows.

a vehicle information acquisition unit configured to acquire various kinds of vehicle information which can be detected by the vehicle; a controller configured to control display of the video image based on the vehicle information acquired by the vehicle information acquisition unit; a video image display configured to form the video image based on an instruction from the controller; a mirror configured to reflect the video image formed by the video image display to project onto the windshield; a mirror driver configured to change an angle of the mirror based on an instruction from the controller; and a display distance adjusting mechanism configured to adjust a display distance of the virtual image with respect to the driver. A head-up display apparatus according to a typical embodiment of the present invention which displays a virtual image to be overlapped with scenery in front of a vehicle with respect to a driver by projecting a video image onto a windshield of the vehicle, the head-up display apparatus includes:

Then, the controller adjusts the angle of the mirror via the mirror driver based on the vehicle information such that the virtual image can be displayed with respect to the driver to be overlapped with the scenery.

Effects of the Invention

Effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

Specifically, according to the typical embodiment of the present invention, it is possible to display a virtual image to be suitably overlapped with actual scenery in accordance with a running condition of a vehicle in an AR-HUD.

Hereinafter, embodiments of the present invention will be described in detail in accordance with the drawings. Note that the same components are denoted by the same reference characters throughout the drawings for describing the embodiments in principle, and the repetitive description thereof is omitted. Meanwhile, illustration of a portion which has been denoted by a reference character and described in a figure is not repeated in describing another figure, but the portion may be referred to by denoting the same reference character.

<Apparatus Configuration>

2 FIG. 1 30 51 52 3 2 is a view illustrating an outline of an example of an operation concept of a head-up display apparatus according to one embodiment of the present invention. In an AR-HUDof the present embodiment, a video image displayed on a video image displayconstituted by a projector, an LCD (liquid Crystal Display), and the like is reflected by a mirrorand a mirror(for example, a free-form surface mirror, a mirror having an asymmetric shape with respect to an optical axis, or the like) and projected onto a windshieldof a vehicle.

5 3 3 52 3 5 A driversees the video image projected onto the windshieldand then, visually recognizes the above video image as a virtual image through the transparent windshieldin front thereof. In the present embodiment, as described later, by adjusting an angle of the mirror, a position where the video image is projected onto the windshieldis adjusted, so that it is possible to adjust a display position of the virtual image which the driversees, in an upward and downward direction. Also, by using various kinds of methods described later, it is also possible to adjust a display distance, for example, displaying the virtual image near (for example, 2 to 3 m ahead) or displaying the virtual image far (for example, 30 to 40 m ahead). Then, adjusting the display position and the display distance of the virtual image such that the virtual image is overlapped with scenery outside the vehicle (a road, a building, a person, etc.) achieves an AR function.

1 FIG. 1 FIG. 1 2 10 20 30 40 50 52 60 2 is a functional block diagram illustrating an outline of an overall configuration example of the head-up display apparatus according to the one embodiment of the present invention. The AR-HUDmounted in the vehicleincludes, for example, a vehicle information acquisition unit, a controller, the video image display, a display distance adjusting mechanism, a mirror driver, the mirror, and a speaker. Note that, although a shape of the vehicleis displayed like a passenger car in the example of, it is not limited to this and can be appropriately applied to all kinds of general vehicles.

10 2 10 2 4 4 2 The vehicle information acquisition unitincludes information acquisition devices such as various types of sensors set up in respective units of the vehicleto be described later, and the vehicle information acquisition unitdetects various events generated in the vehicleand detects and acquires values of various parameters relating to a running condition at a predetermined interval, thereby acquiring vehicle informationto output. The vehicle informationcan include, as illustrated, speed information and gear information of the vehicle, handle steering angle information, lamp lighting information, external light information, distance information, infrared ray information, engine ON/OFF information, camera video image information (inside a vehicle/outside a vehicle), acceleration gyro information, GPS (Global Positioning System) information, navigation information, vehicle-to-vehicle communication information, road-to-vehicle communication information, and the like, for example.

20 1 20 20 30 4 10 52 3 2 FIG. The controllerhas a function of controlling an operation of the AR-HUDand for example, is mounted with a CPU (Central Processing Unit) and software executed thereby. The controllermay be mounted with hardware such as a microcomputer or an FPGA (Field Programmable Gate Array). As illustrated also in, the controllerdrives the video image displayto form a video image to be displayed as a virtual image based on the vehicle informationand the like acquired from the vehicle information acquisition unitand has the video image reflected appropriately by the mirroror the like, thereby projecting the video image onto the windshield. Then, by a method described later, control such as adjusting the display position of a display region of the virtual image or adjusting the display distance of the virtual image is performed.

30 20 40 5 20 As described above, the video image displayis a device constituted by the projector and the LCD, for example, and forms a video image for displaying a virtual image based on an instruction from the controllerto project and display the video image. The display distance adjusting mechanismis a mechanism for adjusting a distance of a virtual image to be displayed from the driverbased on an instruction from the controller, and for example, is mounted with any one or more of various kinds of display distance adjusting methods described later.

50 52 20 60 1 5 The mirror driveradjusts an angle of the mirrorbased on an instruction from the controllerand adjusts a position of the display region of the virtual image in the upward and downward direction. Adjusting the position of the display region of the virtual image will be described later. The speakerperforms audio output relating to the AR-HUD. For example, it is possible to perform voice guidance of the navigation system, audio output in notifying the driverof a warning etc. by the AR function, and the like.

3 FIG. 4 10 20 4 21 21 is a view illustrating an outline of an example of a hardware configuration relating to acquisition of the vehicle informationin the head-up display apparatus according to the present embodiment. Herein, part of the hardware configuration of the vehicle information acquisition unitand the controllerare mainly indicated. Acquisition of the vehicle informationis, for example, performed by the information acquisition devices such as various types of sensors connected to an ECU (Electronic Control Unit)under control of the ECU.

101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 4 These information acquisition devices include, for example, a vehicle speed sensor, a shift position sensor, a handle steering angle sensor, a headlight sensor, an illuminance sensor, a chromaticity sensor, a distance measuring sensor, an infrared ray sensor, an engine start sensor, an acceleration sensor, a gyro sensor, a temperature sensor, a road-to-vehicle communication wireless receiver, a vehicle-to-vehicle communication wireless receiver, a camera (inside the vehicle), a camera (outside the vehicle), a GPS receiver, a VICS (Vehicle Information and Communication System, registered trademark (the same applies hereinafter)) receiver, and the like. It is not always necessary to include all the devices, and other kinds of devices may be included. It is possible to appropriately use the vehicle informationwhich can be acquired by a device included.

101 2 102 2 103 104 105 106 107 2 108 2 109 The vehicle speed sensoracquires the speed information of the vehicle. The shift position sensoracquires the current gear information of the vehicle. The handle steering angle sensoracquires the handle steering angle information. The headlight sensoracquires the lamp lighting information relating to ON/OFF of the headlight. The illuminance sensorand the chromaticity sensoracquire the external light information. The distance measuring sensoracquires the distance information between the vehicleand an external object. The infrared ray sensoracquires the infrared ray information relating to presence/absence of an object at a close distance of the vehicle, a distance, and the like. The engine start sensordetects the engine ON/OFF information.

110 111 2 112 113 114 2 2 2 The acceleration sensorand the gyro sensoracquire the acceleration gyro information including acceleration and angle speed as information of posture and behavior of the vehicle. The temperature sensoracquires the temperature information inside and outside the vehicle. The road-to-vehicle communication wireless receiverand the vehicle-to-vehicle communication wireless receiveracquire the road-to-vehicle communication information received by road-to-vehicle communication between the vehicleand a road, a road sign, a traffic light, etc., and the vehicle-to-vehicle communication information received by vehicle-to-vehicle communication between the vehicleand other vehicles around the vehicle, respectively.

115 116 115 5 5 116 2 2 The camera (inside the vehicle)and the camera (outside the vehicle)shoot moving images of conditions inside the vehicle and outside vehicle to acquire the camera video image information (inside the vehicle/outside the vehicle), respectively. The camera (inside the vehicle)shoots a posture, a position of the eye, and motion of the driver, for example. By analyzing obtained moving images, it is possible to grasp a fatigue condition and a position of the line of sight of the driver, for example. Also, the camera (outside the vehicle)shoots a surrounding condition such as the front and the back of the vehicle. By analyzing obtained moving images, it is possible to grasp presence/absence of a moving object such as other vehicle and a person around the vehicle, a building and geography, a road surface condition (rain, fallen snow, frozen, bump, etc.), and the like, for example.

117 118 The GPS receiverand the VICS receiveracquire the GPS information obtained by receiving a GPS signal and the VICS information obtained by receiving a VICS signal, respectively. These receivers maybe mounted as apart of the car navigation system acquiring these pieces of information to use.

4 FIG. 4 FIG. 30 30 31 32 33 31 32 31 33 33 is a functional block diagram illustrating details of a configuration example of the head-up display apparatus according to the present embodiment. The example ofillustrates a case in which the video image displayis a projector, and the video image displayincludes a light source, an illumination optical system, and a display element, for example. The light sourceis a component generating an illumination light for projection, and for example, a high pressure mercury lamp, a xenon lamp, an LED (Light Emitting Diode) light source, a laser light source, or the like can be used. The illumination optical systemis an optical system collecting the illumination light generated in the light sourceand further homogenizing the illumination light to irradiate the display element. The display elementis an element generating a video image to be projected, and for example, a transmission liquid crystal panel, a reflective liquid crystal panel, a DMD (Digital Micromirror Device) (registered trademark) panel, or the like can be used.

20 21 22 23 24 25 26 27 28 29 21 4 10 23 24 23 21 1 3 FIG. More specifically, the controllerincludes an ECU, an audio output unit, a non-volatile memory, a memory, a light source adjusting unit, a distortion correction unit, a display element driver, a display distance adjusting unit, a mirror adjusting unit, and the like. As illustrated in, the ECUacquires the vehicle informationvia the vehicle information acquisition unit, records and stores the acquired information in the non-volatile memoryor the memory, and reads out the acquired information therefrom, as needed. The non-volatile memorymay have setting information such as setting values and parameters for various controls stored therein. Also, the ECUgenerates a video image data relating to a virtual image to be displayed as the AR-HUDby executing a dedicated program, or the like.

22 60 25 31 30 31 31 30 21 3 2 26 3 27 26 33 The audio output unitoutputs audio information via the speakeras needed. The light source adjusting unitadjusts a light emitting amount of the light sourceof the video image display. When there are a plurality of light sources, it may be configured so as to control the plurality of light sourcesindividually. When the video image displayprojects a video image generated by the ECUonto the windshieldof the vehicle, the distortion correction unitcorrects a distortion of the video image generated due to a curvature of the windshieldby image processing. The display element driversends a drive signal in accordance with a video image data corrected by the distortion correction unitto the display element, thus generating a video image to be projected.

28 40 30 29 52 50 When the display distance of the virtual image needs to be adjusted, the display distance adjusting unitdrives the display distance adjusting mechanismto adjust the display distance of the video image to be projected from the video image display. Various methods of adjusting the display distance of the virtual image will be described later. When a position of the display region of the virtual image itself needs to be adjusted, the mirror adjusting unitchanges an angle of the mirrorvia the mirror driverto move the display region of the virtual image up and down. Position adjustment of the display region of the virtual image will be also described later.

5 FIG. 28 20 21 281 282 283 284 285 40 401 402 403 404 405 is a view illustrating details of a configuration example relating to display distance adjustment in the head-up display apparatus of the present embodiment. The display distance adjusting unitof the controllerfurther includes, as each unit controlled individually by the ECU, a functional liquid crystal film ON/OFF controller, a lens movable unit, alight control mirror ON/OFF controller, a diffuser movable unit, and an optical filter movable unit, for example. Also, as hardware, devices, and the like controlled and driven by these units, the display distance adjusting mechanismfurther includes a functional liquid crystal film, a lens movable mechanism, a light control mirror, a diffuser movable mechanism, an optical filter movable mechanism, and the like. Adjusting method of the display distance of the virtual image by each of these units will be described later.

1 Note that the AR-HUDdoes not need to include all of these respective units, devices, and the like, and it is sufficient if each unit required for mounting applicable one of the adjusting methods of the display distance of the virtual image described later may be appropriately provided.

<Contents of Processes>

6 FIG. 2 1 1 1 10 20 2 20 105 106 4 3 25 31 4 is a flow chart illustrating an outline of an example of an initial operation in the head-up display apparatus of the present embodiment. When an ignition switch is turned ON in the vehicleduring stopping and a power supply of the AR-HUDis then turned ON (S), the AR-HUDfirst acquires vehicle information by the vehicle information acquisition unitbased on an instruction from the controller(S). Then, the controllercalculates a suitable brightness level based on external light information acquired by the illuminance sensor, the chromaticity sensor, and the like, of the vehicle information(S) and has the light source adjusting unitcontrol a light emitting amount of the light sourceto set such that the brightness level becomes the calculated brightness level (S). For example, when the external light is bright, the brightness level is set to high, and when the external light is dark, the brightness level is set to low.

21 5 26 6 27 33 7 3 5 21 28 8 28 40 30 9 Subsequently, the ECUdecides and generates a video image (an initial image, for example) to be displayed as the virtual image (S), and after a process of correcting a distortion of the generated video image by the distortion correction unitis performed (S), the display element driverdrives and controls the display elementto forma video image to be projected (S). As a result, the video image is projected onto the windshield, so that the drivercan visually recognize the virtual image. Subsequently, the ECUor the display distance adjusting unitcalculates and decides the display distance of the virtual image (S), and the display distance adjusting unitdrives the display distance adjusting mechanismto control the display distance of the video image projected from the video image display(S).

1 20 11 20 12 12 11 11 1 13 When the entire AR-HUDhas completed activation and start of each unit also including a series of initial operation described above, an HUD-ON signal is output, and the controllerdetermines whether or not this signal is received (S). When this signal is not received, the controllercontinues to standby for receiving the HUD-ON signal for a certain period of time (S) and repeats a standby process of receiving the HUD-ON signal (S) until it is determined that the HUD-ON signal is received in the step S. When it is determined that the HUD-ON signal is received in the step S, normal operation of the AR-HUDdescribed later starts (S), and a series of initial operation ends.

7 FIG. 6 FIG. 1 10 20 21 20 105 106 4 22 is a flow chart illustrating an outline of an example of normal operation in the head-up display apparatus of the present embodiment. Also in the normal operation, basic flow of processes is substantially the same as the initial operation illustrated indescribed above. First, the AR-HUDacquires vehicle information by the vehicle information acquisition unitbased on an instruction from the controller(S). Then, the controllerperforms a brightness level adjusting process based on external light information acquired by the illuminance sensor, the chromaticity sensor, and the like, of the vehicle information(S).

8 FIG. 221 222 25 31 223 222 221 is a flow chart illustrating an outline of an example of the brightness level adjusting process in the head-up display apparatus of the present embodiment. When the brightness level adjusting process starts, first, a suitable brightness level is calculated based on the acquired external light information (S). Then, by comparing the calculated brightness level with the brightness level currently set, it is determined whether or not the brightness level needs to be changed (S). When the change is not necessary, the brightness level adjusting process ends as it is. Conversely, when the change is necessary, the light source adjusting unitcontrols the light emitting amount of the light sourceto set such that the brightness level becomes the brightness level after the change (S), and the brightness level adjusting process ends. Note that, in the step S, even when there is difference between the suitable brightness level calculated in the step Sand the brightness level currently set, it may be determined that the brightness level needs to be changed only when the difference is a predetermined threshold value or more.

7 FIG. 4 21 21 23 4 4 Subsequently, returning to, a current video image to be displayed as a virtual image is changed based on the latest vehicle informationacquired in the step Sby the ECU, as needed, and a changed video image is decided and generated (S). Note that there may be a large number of patterns in which display contents are changed based on the vehicle informationin accordance with contents of the acquired vehicle information, a combination thereof, etc. For example, various patterns maybe possible; a case in which numeral values of speed display which are displayed all the time are changed when the speed information is changed or a case in which an arrow figure for guide is displayed or deleted based on the navigation information or in which a shape, a display position, or the like of the arrow are changed.

2 52 50 24 2 25 24 25 Subsequently, in the present embodiment, adjustment and correction processes for maintaining visibility, suitability of the display contents, and the like are performed in accordance with the running condition of the vehicle. First, when it is required to adjust a position of the display region of the virtual image itself, an angle of the mirroris changed via the mirror driver, and the mirror adjusting process of moving the display region of the virtual image up and down is performed (S). Subsequently, the vibration correction process of correcting the display position of the video image in the display region with respect to vibration of the vehicleis further performed (S). Detailed contents of the adjustment and correction processes in the steps Sand Swill be described later.

26 26 27 33 27 21 28 28 28 40 30 29 Subsequently, after a process of correcting a distortion of the adjusted and corrected video image is performed by the distortion correction unit(S), the display element driverdrives and controls the display elementto form a video image to be projected (S). Then, the ECUor the display distance adjusting unitcalculates and decides the display distance of the virtual image (S), and the display distance adjusting unitdrives the display distance adjusting mechanismto control the display distance of the video image projected from the video image display(S).

2 1 20 30 21 In executing a series of normal operation described above, the power supply is turned OFF in association with stopping of the vehicle, the HUD-OFF signal is output to the AR-HUD, and the controllerdetermines whether or not this signal is received (S). When the HUD-OFF signal is not received, the process returns to the step S, and the series of normal operation is repeated until the HUD-OFF signal is received. When it is determined that the HUD-OFF signal is received, the series of normal operation ends.

<Mirror Adjusting Process>

9 FIG. 2 5 5 6 is a diagram illustrating an outline of an example of adjusting a position of the display region of the virtual image up and down in the head-up display apparatus of the present embodiment. For example, in each of the left, the center, and the right figures, a state in which a condition of a grade of a road on which the vehicleis running and a condition of a line of sight of the driverare seen in a side view is schematically illustrated on an upper part. Also, on a lower part, in each state, forward scenery outside the vehicle which is seen by the driver, and a condition of a position of the display region(a rectangle frame of a broken line) of the virtual image which is displayed to be overlapped with the forward scenery are schematically illustrated.

2 2 6 6 6 9 FIG. 9 FIG. In the left figure, as illustrated in the upper part thereof, a case in which the grade of the road at the current place of the vehicle(in an advancing direction) and the grade of the forward road (in the advancing direction) are substantially the same, that is, a case in which the vehicleis running on the road which is substantially flat is illustrated. In this case, as illustrated in the lower part of the figure, in order to display the virtual image (an exclamation mark or an image in the example of) to be overlapped with the forward scenery outside the vehicle (a forward vehicle running on the road in the example of) by the AR function, a position in the upward and downward direction of the display regionof the virtual image may remain a normal state. That is, the position of the display regionillustrated in the lower part of the left figure becomes a basic display position in the upward and downward direction of the display region.

2 2 5 5 2 In contrast, in the center figure, a case in which the grade of the road at the current place of the vehicle(in the advancing direction) is larger than the grade of the forward road (in the advancing direction), that is, a case in which the vehicleis running on the road where the forward road is a descending slope is illustrated. In this case, as illustrated in the upper part thereof, in order to put the forward road in a field of view of the driverwith respect to a height of the field of view of the driver(a frame of a solid line in the figure) based on the grade at a position of the vehicle, the field of view needs to be moved in the downward direction (a frame of a dotted line in the figure).

6 6 Then, in this case, as illustrated in the lower part of this figure, if the display position of the display regionof the virtual image remains in the basic display position (a rectangle of the dotted line), it is not possible to overlap the virtual image with the forward scenery outside the vehicle by the AR function, and accordingly, it is required to move the display regionitself in the downward direction in order to display in the overlapping manner.

2 2 5 5 2 6 6 Similarly, in the right figure, a case in which the grade of the road at the current place of the vehicle(in the advancing direction) is smaller than the grade of the forward road (in the advancing direction), that is, a case in which the vehicleis running on the road where the forward road is an ascending slope is illustrated. In this case, as illustrated in the upper part of the figure, in order to put the forward road in the field of view of the driverwith respect to the height of the field of view of the driver(a frame of the solid line in the figure) based on the grade at a position of the vehicle, the field of view needs to be moved in the upward direction (a frame of the dotted line in the figure). Then, also in this case, as illustrated in the lower part of this figure, if the display position of the display regionof the virtual image remains in the basic display position (a rectangle of the dotted line), it is not possible to overlap the virtual image with the forward scenery outside the vehicle by the AR function, and accordingly, it is required to move the display regionitself in the upward direction in order to display in the overlapping manner.

6 2 5 6 5 2 5 9 FIG. Thus, the condition in which the position of the display regionof the virtual image needs to be moved in the upward and downward direction in accordance with the running condition is not limited to a case in which there is a certain amount or more of a difference between the grade at the current place and the grade on the forward road illustrated in the example of. For example, when the speed of the vehicleincreases on a highway or the like, the line of sight of the drivergenerally sees farther, comparing to the time of normal driving, and accordingly, the height of the field of view moves in the upward direction. Accordingly, for example, in order to overlap the virtual image with scenery outside the vehicle including other vehicles etc. which are present further ahead of the forward vehicle comparing to the time of normal driving, a need to move the display regionin the upward direction may be generated. The same also applies to a case or the like in which, when a posture and a body position of the driverchange in running the vehicle, for example, the height position of the eyes of the driveritself changes, and as a result, the height of the field of view moves in the upward and downward direction.

24 52 50 2 7 FIG. 9 FIG. In the present embodiment, in the mirror adjusting process in the step Sofdescribed above, an angle of the mirroris controlled by the mirror driverin accordance with the running condition of the vehicle, and the position of the display region of the virtual image in the upward and downward direction is adjusted as illustrated in the example of.

10 FIG. 7 FIG. 24 52 241 4 52 242 is a flow chart illustrating an outline of the example of the mirror adjusting process in the step Sof. When the mirror adjusting process starts, a current angle of the mirroris first acquired (S), and further, based on the vehicle information, a current value of a parameter relevant to adjustment of the angle of the mirror(that is, adjustment of the display position of the display region of the virtual image) is acquired (S).

9 FIG. 2 2 A kind of parameter to be required may be different depending on under what conditions the display position of the display region is adjusted. For example, in the example of, as the relevant parameter value, a value indicating a difference between the grade at the current place of the vehicleand the grade of the forward road (relative grade) is acquired. For example, it is possible to grasp the grade at the current place from information on an inclination of the vehicleobtained by the acceleration gyro information. Also, by analyzing the camera video image information outside the vehicle, it is also possible to grasp the grade of the forward road. In addition, it is also possible to obtain the grades of the current place and the forward road based on three-dimensional road and topographical information and the like obtained from the navigation information.

242 52 243 52 9 FIG. Next, based on the parameter value acquired in the step S, a target angle of the mirroris calculated based on a reference, a condition, etc. determined in advance (S). A kind of logic used to calculate the target angle based on the parameter may vary depending on the condition in which the display position of the display region is adjusted. For example, in the example of, when an absolute value of the relative grade between the current place and the forward road is a predetermined threshold value or more, the target angle of the mirroris decided in accordance with a reference character of the relative grade. The predetermined threshold value described above can be set to, for example, 1/x (x is a predetermined value) of an FOV (Field Of View) of the display region of the virtual image in the upward and downward direction.

52 242 2 2 Note that, in the present embodiment, although it is configured such that the target angle of the mirroris calculated based on the current parameter value acquired in the step S, a condition in the near future is predicted based on information of history of the current parameter value and past values, and the target angle may be calculated based on the predicted result. For example, by analyzing a tendency of a transition of the values based on the history of the parameter values in the past, the parameter value in the near future may be predicted based on the tendency. Also, by analyzing the camera video image information ahead of and outside the vehicle, it is also possible to predict a condition around the vehiclein the near future and to grasp a road condition ahead of the vehiclebased on the navigation information.

52 241 52 243 244 52 2 2 Next, presence/absence of a difference between the current angle of the mirroracquired in the step Sand the target angle of the mirroracquired in the step Sis determined (S). Upon determination, for example, when the difference is a predetermined threshold value or more, it may be determined that the difference is present, and when the difference is less than the threshold value, it may be determined that the difference is not present. Also, it may be determined that the difference is present only if the state in which the difference is present continues for a certain period of time or more. Accordingly, it is possible to eliminate, from an object for adjustment of the mirror, an event in which the inclination of the vehiclechanges temporarily and instantaneously, for example, a case in which the vehicleruns on a step such as a curb.

244 52 52 245 52 50 52 246 245 52 50 52 52 247 50 When it is determined that the difference in angle is not present in the step S, the mirror adjusting process ends as it is. That is, the angle of the mirroris not adjusted but remains the current angle. In contrast, when it is determined that the difference in angle is present, the mirroris rotated in a specified direction so as to be the target angle (S). In particular, a mirror adjusting signal for rotating the mirroris output to the mirror driver. Then, it is determined whether or not the mirrorhas reached the target angle (S), and when it hasn't reached, the process returns to the step S, and the rotation of the mirrorcontinues. That is, the mirror adjusting signal continues to be output to the mirror driver. In contrast, when the mirrorhas reached the target angle, rotation of the mirroris stopped (S). That is, output of the mirror adjusting signal to the mirror driveris stopped. Then, a series of mirror adjusting processes ends.

<Vibration Correction Process>

11 FIG. 7 FIG. 25 2 4 251 2 4 2 2 is a flow chart illustrating an outline of an example of the vibration correction process in the step Sof. When the vibration correction process starts, information on a vibration amount of the vehicleis first acquired based on the vehicle information(S). For example, it is possible to grasp the vibration amount (an amount of an up-and-down motion in a short cycle in the vehicle) based on the acceleration gyro information, the camera video image information outside the vehicle, and the like. Note that, in the present embodiment, although the vibration information is acquired based on the current vehicle information, for example, by analyzing the camera video image information ahead of and outside the vehicle, a condition of a road surface around the vehiclein the near future is predicted, and based on this, it may be configured to predict the vibration amount of the vehiclein the near future.

251 252 253 2 2 254 Subsequently, it is determined whether or not the vibration amount acquired in the step Sis a predetermined threshold value or more (S). When the vibration amount is less than the threshold value, it is determined that the vibration is very small, and the vibration correction process ends as it is. That is, correction of the display video image in association with the vibration is not performed. In contrast, when the vibration amount is the threshold value or more, a display shift amount of the video image in the display region is calculated (S). For example, based on a ratio between an actual height of the vehicleand a height of the display region of the virtual image, the display shift amount of the video image in the display region is calculated from the vibration amount of the vehicle. Then, based on the calculated display shift amount, the display position of the video image in the display region is offset up and down (S), and a series of vibration correction process ends.

<Display Distance Adjustment of Virtual Image>

28 20 40 30 28 40 5 FIG. When the display distance of the virtual image needs to be adjusted, the display distance adjusting unitof the controllerdrives the display distance adjusting mechanismto adjust the display distance of the video image projected from the video image display. In the following, an adjusting method of the display distance of the virtual image in each unit of the display distance adjusting unitand the display distance adjusting mechanismillustrated inwill be described below.

<Functional Liquid Crystal Film>

12 12 FIGS.(a) and(b) 12 FIG. 12 FIGS. 401 401 41 12 401 5 are views illustrating an outline of an example of display distance adjustment using a functional liquid crystal filmin the head-up display apparatus of the present embodiment. In the example of, a plurality of the functional liquid crystal filmsare used as a diffusera. Then, as illustrated in each of(a) and(b), by changing a portion in a white state for each area of each of the functional liquid crystal films, a focus distance is changed for each area, so that the display distance of the virtual image (a distance between a position of the eyes of the driverand the display position of the virtual image) is changed.

13 FIG. 41 401 401 401 30 401 is a view illustrating an outline of a configuration example of the diffusera constituted by the functional liquid crystal films. The functional liquid crystal filmis a film capable of controlling a transmitted state and the white state by electricity. A part in the white state of the functional liquid crystal filmserves a function of the diffuser, and the video image projected by a projectora is formed at this part in the white state. In this present embodiment, it is assumed to control the plurality of functional liquid crystal filmsso as to individually become the white state for each of a plurality of areas.

12 FIG. 5 FIG. 30 401 42 401 401 42 30 401 281 Returning to, in a configuration illustrated in the figure, the display position of the virtual image based on the video image projected from the projectora is decided in accordance with the distance between the part in the white state of each of the functional liquid crystal filmsand the lensa. Accordingly, the plurality of functional liquid crystal filmsare disposed such that the distance from each of the functional liquid crystal filmsto the lensa becomes different, and regarding the video image projected from the projectora, any one of the functional liquid crystal filmsis set in the white state for each area by the functional liquid crystal film ON/OFF controllerillustrated in, so that the display distance of the virtual image can be changed for each area.

12 FIG.(a) 12 FIG.(b) 401 42 401 401 42 401 In particular, for example, as illustrated in, for a subject area (an uppermost area, for example), only the functional liquid crystal filmwhich is disposed at the closest position to the lensa is set in the white state, and the other functional liquid crystal filmsare set in the transmitted state, so that the display distance of the corresponding virtual image can be shortest. Conversely, as illustrated in, for the subject area (the uppermost area, for example), only the functional liquid crystal filmwhich is disposed at the farthest position from the lensa is set in the white state, and the other functional liquid crystal filmsare set in the transmitted state, so that the display distance of the corresponding virtual image can be farthest.

12 13 FIGS.and 401 Note that, although a case in which the video image to be displayed is provided with three areas in the upward and downward direction is exemplified in the examples of, the number of areas is not limited to this also including examples to be described below, and the areas can be divided not only in the upward and downward direction, but also in the right and left direction as a matter of course. Also, the number of functional liquid crystal filmsis also not limited to three illustrated in the figures and can be appropriately changed in accordance with the number of areas.

<Disposition of Plurality of Mirrors>

14 FIG. 14 FIG. 51 30 42 30 51 42 30 42 is a view illustrating an outline of an example of display distance adjustment using a plurality of mirrors in the head-up display apparatus of the present embodiment. In the example of, a plurality of mirrorsa are disposed between an LCDb and the lensa as illustrated, and a video image from the LCDb is reflected by each of the mirrorsa which is different for each area to be incident on the lensa. Accordingly, a distance from the LCDb to the lensa is made different for each area, so that the display distance of the virtual image can be changed in accordance with this distance.

14 FIG. 30 51 42 30 In particular, for example, as illustrated in, by displaying the video image on the LCDb in the area reflected by the mirrora (which is also the farthest from the lensa) disposed at the farthest position from the LCDb, it is possible to make the display distance of the corresponding virtual image farthest.

30 51 42 30 Conversely, by displaying the video image on the LCDb in the area reflected by the mirrora (which is also the closest to the lensa) disposed at the closest position from the LCDb, it is possible to make the display distance of the corresponding virtual image closest.

14 FIG. 51 Note that, also in the example of, the number of mirrorsa is not limited to three illustrated in the figure, but can be appropriately changed in accordance with the number of areas.

[Movable Lens]

15 FIG. 15 FIG. 30 41 52 42 is a view illustrating an outline of an example of display distance adjustment using a movable lens in the head-up display apparatus of the present embodiment. In the example of, the video image projected from the projectora is formed by a diffuserb and then, incident on the mirrorvia movable lensesb separately provided in a plurality of areas.

42 282 402 30 41 42 42 5 FIG. Here, each of the movable lensesb can be individually moved along an optical axis direction by the lens movable unitand the lens movable mechanismillustrated in. The display position of the virtual image based on the video image projected from the projectora is decided in accordance with the distance between the diffuserb and each of the movable lensesb. Thus, moving the movable lensb changes the focus distance for each area, so that the display distance of the virtual image can be changed.

15 FIG. 42 41 42 41 In particular, for example, as illustrated in, as in the uppermost area, the movable lensb is moved to a position close to the diffuserb, so that it is possible to make the display distance of the corresponding virtual image closer. Conversely, as in the lowermost area, the movable lensb is moved to a position far from the diffuserb, so that it is possible to make the display distance of the corresponding virtual image farther.

15 FIG. 42 Note that, also in the example of, the number of movable lensesb is not limited to three illustrated in the figure, but can be appropriately changed in accordance with the number of areas.

[Light Control Mirror]

16 16 FIGS.(a) and(b) 16 FIG. 51 403 30 42 51 are views illustrating an outline of an example of display distance adjustment using a light control mirrorb in the head-up display apparatus of the present embodiment. In the example of, a plurality of light control mirrorsare disposed between the LCDb and the lensa so as to be in rows and columns when seen in a sectional direction as illustrated in the figures, thereby constituting the light control mirrorb.

16 16 FIGS.(a) and(b) 403 30 42 Then, as illustrated in, changing a portion of the light control mirrorsto be set in the mirror state makes the distance from the LCDb to the lensa different for each area, and in accordance with this distance, it is possible to change the display distance of the virtual image.

17 FIG. 403 403 403 30 403 42 403 283 403 is a view illustrating an outline of a configuration example of the light control mirror. The light control mirroris a component such as a film, a sheet, or a glass capable of controlling the transmitted state and the mirror state by electricity. The light control mirrorin the transmitted state transmits the video image from the LCDb, and only the light control mirrorin the mirror state reflects the video image in a direction of the lensa. In the present embodiment, it is assumed that the plurality of light control mirrorsdisposed in rows and columns when seen in a sectional direction are controlled by the light control mirror ON/OFF controllersuch that one light control mirroronly becomes the mirror state per a row and a column (each area).

16 FIG.(a) 403 42 403 403 30 42 403 42 403 403 30 42 In particular, for example, as illustrated in, for an area corresponding to a column of the light control mirrorswhich is closest to the lensa, only the light control mirrorin the lowermost row is set to the mirror state, and the other light control mirrorsare set to the transmitted state, so that an optical path length from the LCDb to the lensa can be made shortest, whereby the display distance of the corresponding virtual image can be made closest. Conversely, for an area corresponding to a column of the light control mirrorswhich is farthest from the lensa, only the light control mirrorin the uppermost row is set to the mirror state, and the other light control mirrorsare set to the transmitted state, so that an optical path length from the LCDb to the lensa can be made longest, whereby the display distance of the corresponding virtual image can be made farthest.

16 FIG.(b) 403 42 403 403 42 403 403 30 42 403 42 403 403 30 42 Also, for example, as illustrated in, for an area corresponding to a column of the light control mirrorswhich is closest to the lensa, only the light control mirrorin the uppermost row is set to the mirror state, and for an area corresponding to a column of the light control mirrorswhich is second closest to the lensa, only the light control mirrorin the lowermost row is set to the mirror state, and the other light control mirrorsare set to the transmitted state. Thus, optical path lengths from the LCDb to the lensa in these areas can be made relatively shorter, so that the display distances of the corresponding virtual images can be made closer. Conversely, for an area corresponding to a column of the light control mirrorswhich is farthest from the lensa, only the light control mirrorin the middle row is set to the mirror state, and the other light control mirrorsare set to the transmitted state. As a result, an optical path length from the LCDb to the lensa can be made relatively longer than those in the other areas, so that the display distance of the corresponding virtual image can be made farther.

16 17 FIGS.and 403 Note that, also in the examples of, the number of light control mirrorsis not limited to three rows and three columns illustrated in the figures, but can be appropriately changed in accordance with the number of areas.

[Movable Diffuser]

18 FIG. 18 FIG. 30 41 52 42 is a view illustrating an outline of an example of display distance adjustment using a movable diffuser in the head-up display apparatus of the present embodiment. In the example of, the video image projected from the projectora is formed by a movable diffuserc and then, incident on the mirrorvia the lensa.

41 284 404 30 41 42 41 5 FIG. Here, the movable diffuserc can be moved and/or rotated along the optical axis direction by the diffuser movable unitand the diffuser movable mechanismillustrated in. The display position of the virtual image based on the video image projected from the projectora is decided in accordance with a distance and/or an inclination between the movable diffuserc and the lensa. Thus, moving and/or rotating the movable diffuserc can change the focus distance, thereby changing the display distance of the virtual image.

41 42 41 42 In particular, by moving and/or rotating the movable diffuserc at a position close to the lensa, the display distance of the virtual image can be made closer. Conversely, by moving and/or rotating the movable diffuserc at a position farther from the lensa, the display distance of the virtual image can be made farther.

[Movable Optical Filter]

19 19 FIGS.(a) and(b) 19 FIG. 19 19 FIGS.(a) and(b) 43 42 41 43 are views illustrating an outline of an example of display distance adjustment using a movable optical filter in the head-up display apparatus of the present embodiment. In the examples of, the movable optical filtera is provided between the lensa and the diffuserb, and as illustrated in, the movable optical filtera is inserted into or extracted from the optical path, thereby changing the focus distance for each area to change the display distance of the virtual image.

43 43 285 405 5 FIG. An optical filter is a component having a characteristic of changing a focus distance by a single optical member such as a lens or a combination. In the present embodiment, a plurality of optical filters each having a different refractive index are used in combination to form one optical filter having a different refractive index for each region, and at the same time, to constitute a movable optical filtera capable of being inserted into or extracted from the optical path. Since the focus distance of the optical filter is different for each region, the movable optical filtera is inserted into or extracted from the optical path by the optical filter movable unitand the optical filter movable mechanismillustrated in, so that the display distance of the virtual image can be changed for each area.

19 FIG.(a) 19 FIG.(b) 43 43 41 42 In particular, for example, as illustrated in, inserting the whole movable optical filtera into the optical path can make the focus distance of the optical filter corresponding to the lowermost area shortest and the display distance of the virtual image far, and at the same time, make the focus distance of the optical filter corresponding to the uppermost area longest and the display distance of the virtual image close. Also, for example, as illustrated in, the movable optical filtera is partially extracted such that the lowermost area does not pass through the optical filter, and accordingly, it is configured that the display distance of the virtual image can be decided by the distance between the diffuserb and the lensa for this area and the display distance of the virtual image in this area can be made farther than those in the other areas which pass through the optical filter.

19 FIG. 43 Note that, also in the examples of, the number of regions whose focus distances in the movable optical filtera are different is not limited to three illustrated in the figures, but can be appropriately changed in accordance with the number of areas.

[Comb-Like Optical Filter]

20 FIG. 20 FIG. 30 41 52 43 42 is a view illustrating an outline of an example of display distance adjustment using a comb-like optical filter in the head-up display apparatus of the present embodiment. In the example of, the video image projected from the projectora is formed by the diffuserb and then, incident on the mirrorvia a comb-like optical filterb and the lensa.

43 30 20 FIG. The comb-like optical filterb is a component whose optical filter portion having the same function as the lens and capable of changing the display distance of the virtual image in accordance with the focus distance is provided in a comb-like shape. As illustrated in, for example, the video image projected from the projectora is made to correspond to each of the optical filter portion and a portion without the optical filter by a line of the video image (which is not limited to each one line, but can be for each arbitrary line), so that the display distance of the virtual image can be changed by a line.

In particular, the display distance of the virtual image based on the video image of the line corresponding to the optical filter portion can be made closer, and the display distance of the virtual image based on the video image of the line corresponding to the portion without the optical filter can be made farther.

2 2 2 As described above, according to the head-up display apparatus of the one embodiment of the present invention, in accordance with the running condition of the vehicle, even in a case in which it is not possible to overlap the virtual image with the scenery in front of the vehicle, the display position of the display region itself of the virtual image is adjusted dynamically in the upward and downward direction, so that the virtual image can be suitably overlapped with the scenery in front of the vehicleto achieve the AR function. Further, in accordance with the running condition and the like, the display distance of the virtual image can be also suitably adjusted.

<Display of Navigation Information>

7 10 FIGS.to According to the above description, for example, indescribed above, there have been descriptions in which display of the navigation information can have various patterns, and further, by the mirror adjusting process and the like for changing the display position thereof, elevation and depression angles of the navigation display are changed in accordance with the road shape. However, in the head-up display apparatus of the present invention, it became clear that, when the above-described navigation display is displayed on the road in an overlapping manner, a case in which it is hard to see the navigation display due to the shape of the road occurs.

In the following, a case in which it is hard to see the navigation display due to the shape of the road and a countermeasure thereof which have been examined by the inventors of the present invention will be described in detail.

21 21 FIGS.(a) and(b) 21 FIG.(b) 21 FIG.(a) 2 351 3 35 3 351 2 34 First, in, a state of normal display when the vehicleis running on a flat road (see) is illustrated. In this state, as illustrated in, a navigation displaycomposed of a plurality of guide arrows indicating an advancing direction of the vehicle is displayed to be overlapped over the road in front of the windshieldinside an HUD display regionof a substantially center portion of the windshieldas the navigation displayis looked down from the driver. Note that, in the figure, the arrow serving as a display object is displayed by changing a size according to a distance from the vehicle, and in the present example, the advancing direction is turning left ahead of the vehicle. Also, a reference characterin the figure indicates a dashboard.

22 22 FIGS.(a) and(b) 22 FIG.(b) 22 FIG.(a) 2 351 35 3 351 Subsequently, in, a state of display when the vehicleis running on an ascending slope and around a top of the ascending slope (see, for example) is illustrated, and in such state, as apparent also from, the navigation displaydisplayed in the HUD display regionin the windshieldis collapsed, and as a result, it becomes hard for the driver to see the navigation display.

23 23 FIGS.(a) and(b) 23 FIG.(b) 2 3 35 351 Also, as illustrated in, when the vehicleis running on a descending slope and around an end of the descending slope (see), the road in front of the windshieldis upwardly out of the HUD display region, and parts indicating the left turn of the navigation displaycannot be displayed.

24 FIG. 3 35 351 Further, when the vehicle gets close to a curve, as illustrated in, the road in front of the windshieldis laterally out of the HUD display region(in this example, on the right side), and similarly to the above, the parts indicating the left turn of the navigation displaycannot be displayed.

25 FIG. 35 351 In addition, also when the vehicle gets close to the ascending slope, as illustrated in, a point where the vehicle turns right or left (right or left turn point) on the road opposite to the top of the ascending slope is hid from the slope and not present in the HUD display region, whereby various problems such as a case in which the navigation displayat the corresponding point cannot be performed have been found.

In view of this, countermeasures which have been examined to solve the above-described problems will be described in detail with reference to the drawings below.

26 FIGS.(a) 22 FIG. 26 FIG.(a) 26 FIG.(b) 26 351 351 351 35 35 First, each ofand(b) particularly illustrates a countermeasure for solving the problem illustrated indescribed above, and herein, the navigation displaycomposed of the plurality of guide arrows indicating the advancing direction of the vehicle is displayed to be overlapped over the road as the navigation displayis looked up from the driver. Note that the navigation display in the case of turning left is displayed inand the navigation display in the case of turning right is displayed in. In other words, the arrows constituting the navigation displayin the HUD display regionare displayed so as to be positioned at an upper portion of the HUD display regionas the arrows are closer to the vehicle, while they are displayed so as to be positioned around the top of the slope as they are farther from the vehicle. Then, display of turning a left or right corner is displayed so as to be positioned around the top of the slope.

27 27 FIGS.(a) and(b) 27 FIG.(a) 27 FIG.(b) 35 3 351 351 351 35 Next, each ofillustrates another countermeasure for solving the problem generated in running on the ascending slope and around the top of the ascending slope described above, and as apparent from these figures, the countermeasure is particularly effective to a case in which, since the HUD display regionin the windshieldis positioned above the top of the slope, the navigation displayonto the road including the corner is impossible. Also in this case, similarly to the above, the navigation displaycomposed of the plurality of guide arrows indicating the advancing direction of the vehicle is displayed to be overlapped over the road as the navigation displayis looked up from the driver. Note that the navigation display in the case of turning left is illustrated inand the navigation display in the case of turning right is illustrated in. Then, in this case, display of turning a left or right corner is displayed so as to be positioned on a lower end of the HUD display region.

28 28 FIGS.(a) and(b) 23 FIG. 28 FIG.(a) 28 FIG.(b) 35 35 352 351 352 352 Subsequently, each ofparticularly illustrates a countermeasure for solving the problem illustrated indescribed above, and particularly, display of turning a left or right corner out of the HUD display regionis performed by using an upper end of the HUD display region. Note that, also in this case,illustrates the navigation display in the case of turning left andillustrates the navigation display in the case of turning right. Note that, in this case, the display of turning the left or right corner described above is performed with arrows having a size corresponding to a distance from the vehicle, and the like. Further, the display of these corners is performed with arrowsin a different mode from the arrowsindicating straight advance along the road, thereby enabling display emphasizing that the arrowsare additional information to the driver. Note that the different display mode of these arrowsincludes display in a different color or blinking display, for example.

29 29 FIGS.(a) to(d) 24 FIG. 29 FIG.(a) 29 FIG.(b) 29 FIG.(c) 29 FIG.(d) 35 352 351 352 35 352 351 352 In addition, each ofparticularly illustrates a countermeasure for solving the problem illustrated indescribed above. That is, under a condition in which the vehicle gets close to a curve and the road is laterally out of the HUD display region, similarly to the above, display of turning a left or right corner is performed by using the arrowsin the different mode from the arrowsindicating straight advance along the road. Note that the display of the arrowsin the different mode is performed at a left side end or a right side end of the HUD display region. In this case,illustrates the navigation display in the case of turning left at the right curve,illustrates the navigation display in the case of turning right at the right curve,illustrates the navigation display in the case of turning left at the left curve, andillustrates the navigation display in the case of turning right at the left curve. Also in this case, the display of the arrowsin the different mode can be performed by setting the color thereof to be different from the arrowsor by blinking in order to emphasize that the arrowsare additional information to the driver.

30 30 FIGS.(a) to(d) 27 FIG. 26 FIG. 29 FIG. 30 FIG.(a) 30 FIG.(b) 30 FIG.(c) 30 FIG.(d) 351 351 352 351 35 35 Also, a countermeasure for a curve around the ascending slope is illustrated in each of. This countermeasure is made by combining the countermeasure illustrated in(or) above with the countermeasure illustrated inabove and is to display the navigation displaycomposed of the plurality of guide arrows described above to be overlapped over the road as the navigation displayis looked up from the driver, and at the same time, to display the arrowsin the different mode from the navigation displayso as to be in the proximity of four corners such as left, right, upper, and lower corners in the HUD display region, under a condition in which the road is downwardly out of the HUD display region. Note that, also in this case,illustrates the navigation display in the case of turning left at the right curve,illustrates the navigation display in the case of turning right at the right curve,illustrates the navigation display in the case of turning left at the left curve, andillustrates the navigation display in the case of turning right at the left curve.

26 FIG. 29 FIG. 35 Note that, in a case in which the countermeasure illustrated inis combined with the countermeasure illustrated in, a position of the arrow indicating a corner in the HUD display regionis only different (that is, is in a substantially center portion in a height direction of the HUD display region), and illustration thereof is omitted herein.

31 31 FIGS.(a) to(d) Then, each ofillustrates a countermeasure at a curve around the end of the descending slope.

35 351 35 352 351 352 35 31 FIG.(a) 31 FIG. 31 FIG.(c) 31 FIG.(d) Similarly, also in this countermeasure, in the HUD display region, the navigation displaycomposed of the plurality of guide arrows is displayed to be overlapped over the road, and at the same time, display of turning a left or right corner out of the HUD display regionis performed with the arrowsin the different mode from the navigation displaysuch that the arrowsare positioned in the proximity of four corners such as left, right, upper, and lower corners in the HUD display region. Note that, also in this case,illustrates the navigation display in the case of turning left at the right curve,(b) illustrates the navigation display in the case of turning right at the right curve,illustrates the navigation display in the case of turning left at the left curve, andillustrates the navigation display in the case of turning right at the left curve.

32 FIG. Subsequently, as one specific example for executing display of the navigation information described above in detail, that is, an operation of changing the navigation display depending on a shape of a road, a flow chart of software therefor is illustrated in.

20 21 23 3 5 FIGS.to 7 FIG. Note that this software is, for example, stored in a memory in the controllerin advance to be executed by the ECU(see, for example) in the process (S) of changing and deciding display video image indescribed above.

32 FIG. 21 311 312 311 313 As illustrated in, first, HUD normal operation is received by the ECU(S), and it is determined whether or not a distance to a corner where the vehicle turns left or right (referred to as “right or left turn point”) is less than a predetermined threshold value (S). As a result, in the case of “no,” the process returns to the HUD normal operation in the step S(S). Note that the predetermined threshold value herein is, for example, a distance from the own vehicle to the left or right turn point and a distance for performing the navigation display to be overlapped with the road, and is set to 100 m by way of example. In other words, when the distance to the left or right turn point is 80 m, the navigation display of the left or right turn point is performed. When the distance to the left or right turn point is 120 m, the navigation display of the left or right turn point is not performed.

312 314 35 3 2 21 31 FIGS.to On the other hand, when the result of determination in the above step Sis “yes,” that is, when the navigation display is performed, determination whether or not a position of the right or left turn point in a perpendicular direction is in the HUD display region described above is further performed (S). Here, the position of the right or left turn point in the perpendicular direction means the position of the right or left turn point in the HUD display regiondisposed in the substantially center portion of the windshieldof the vehicle, as illustrated indescribed above, that is, the position in the longitudinal direction.

314 315 315 316 317 318 21 22 FIGS.and 25 30 FIGS.and 30 FIG. 26 FIG. When a result of determination in this step Sis “yes,” that is, when it is determined that the position of the right or left turn point in the perpendicular direction is in the HUD display region (see, for example), it is further determined whether or not the right or left turn point is at a position where the driver cannot see due to a bump shape of the road (S). Also when a result of determination in this step Sis also “yes,” that is, when it is determined that the right or left turn point is at a position where the driver cannot see due to the bump shape of the road (see, for example), it is further determined whether or not the right or left turn point is on the left side or the right side of the HUD display region (S). Then, when a result is also “yes,” that is, when it is determined that the right or left turn point is outside the HUD display region, for example, the countermeasure illustrated indescribed above (note that it differs in that a height of the corner is in the substantially center portion in the HUD display region) is performed (S). On the other hand, when the result of determination is “no,” that is, when it is determined that the right or left turn point is inside the HUD display region, the countermeasure illustrated indescribed above is performed (S).

315 316 319 320 321 29 FIG. 21 FIG. Meanwhile, when the result of determination in the step Sdescribed above is “no,” that is, when the driver can see the right or left turn point regardless of the bump shape of the road, similarly to the step Sdescribed above, it is determined whether or not the right or left turn point is on the left side or the right side of the HUD display region (S). When a result of determination is “yes,” that is, when it is determined that the right or left turn point is outside the HUD display region, the countermeasure illustrated indescribed above is performed (S). On the other hand, when the result of determination is “no,” that is, when it is determined that the right or left turn point is inside the HUD display region, the normal display illustrated indescribed above is performed (S).

314 322 323 324 325 23 31 FIGS.to 30 FIG. 27 FIG. Further, when the result of determination in the above step Sis “no,” that is, when it is determined that the position of the right or left turn point in the perpendicular direction is not in the HUD display region (see, for example), it is further determined whether or not the right or left turn point is below the lower end of the HUD display region (S). When a result of determination is “yes,” that is, when it is determined that the right or left turn point is below the HUD display region, it is further determined whether or not the right or left turn point is on the left side or the right side of the HUD display region (S). When a result of determination is “yes,” display of the countermeasure illustrated indescribed above is performed (S). On the other hand, when the result of determination is “no,” the normal display illustrated indescribed above is performed (S).

322 326 327 328 31 FIG. 28 FIG. Also, when the result of determination in the above step Sis “no,” that is, when it is determined that the right or left turn point is above the HUD display region, it is further determined whether or not the right or left turn point is on the left side or the right side of the HUD display region (S). When a result of determination is “yes,” display of the countermeasure illustrated indescribed above is performed (S). On the other hand, when the result of determination is “no,” the normal display illustrated indescribed above is performed (S).

That is, according to the processes of the flow chart described above, by changing the mode of the navigation display (including a position in a horizontal direction and a vertical direction in the HUD display region) in accordance with the shape of the road, the head-up display apparatus capable of displaying the virtual image in accordance with the running condition of the vehicle such that the virtual image is suitably overlapped with the actual scenery can be achieved.

3 116 4 1 FIG. 3 FIG. Note that it is a matter of course for those skilled in the art that the shape of the road which variously changes in the windshieldin the embodiments described above can be achieved by a method of analyzing an image and the like by taking in grade information of the road from the navigation information in, taking in video image information ahead of the vehicle from the camera (outside the vehicle)in, and further, although not illustrated, taking in video image information from the camera provided in a vicinity of the eyes (that is, an eye point) of the driver so as to face ahead of the vehicle, among the vehicle informationdescribed above.

<Monocular Vision/Binocular Vision Control of Navigation Information Display>

33 36 FIGS.to Next, in addition to the above-described navigation display in which changes are made in accordance with the shape of the road, further embodiment in which dimensions/shape of an eye box is controlled and switching of monocular vision/binocular vision is performed will be described in detail with reference tobelow.

34 FIG. 34 FIG.(a) 33 FIG. 401 401 73 5 Note that the eye box represents a range of a viewpoint in which display of the video image in the HUD can be visually recognized, and as illustrated in, the functional liquid crystal filmdisposed on an upper surface of the dashboard can control the eye box individually by dividing the filminto right and left areas. For example, when the monocular vision is suitable and set to the right eye according to suitability determination, the right half of the functional liquid crystal film is set to the white state as illustrated in. This block of the video image light results in projection of the video image light only onto the right eye, and as a result, the video image can be seen with the single eye on the right side. Note that, in, this eye box is indicated by a broken lineat a position directly before both eyesof the driver.

33 FIG. 30 52 41 42 401 3 3 In this embodiment, as illustrated in, the video image light projected from the projectora is reflected to the mirrorthrough various kinds of optical membersc anda and further, passes through the functional liquid crystal filmdescribed above, and then, the video image light of the navigation display reflected on the windshieldis projected onto the eyes of the driver. As a result of this, the driver can recognize the navigation display in front of the windshieldas the virtual image. Note that, although an example in which the half of the functional liquid crystal film is set to the white state in order to block the video image light is indicated in this embodiment, it is sufficient if the film does not transmit the light, and the other colors such as grey are applicable.

Meanwhile, in general, when a three-dimensional video image is seen (or watched), the following things have been pointed out. More specifically, (1) when the three-dimensional video image is watched in a bright room, visually induced motion sickness may be alleviated. (2) Since there is a fusional limit, when a parallax is increased to a certain extent or more, the right eye and the left eye do not fuse causing a double image, thereby failing to achieve stereoscopic view. (3) When both eyes are inclined with respect to a display surface, difference between the top and the bottom of the video image seen by the right and left eyes becomes large, and as a result, fusion becomes hard, causing eye fatigue.

Further, (4) as a point to note when a stereoscopic video image is used in a VDT (Visual Display Terminal) operation, particularly, the following things have been pointed out. That is, (4-1) a series of operations should not exceed one hour. (4-2) Operation break time for substantially 10 to 15 minutes should be provided between continuous operations. (4-3) Substantially one or two short breaks should be provided in a series of operation times.

73 401 35 3 34 34 FIG.(a) or(b) 34 FIG.(c) In view of this, in the head-up display apparatus serving as the present invention taking into account the things described above, particularly in display of the navigation information, by controlling switching of a size/shape of the eye box, that is, switching between the monocular vision by either of the right or left eye (see) and the binocular vision by both of the right and left eyes (see) (referred to as “monocular vision/binocular vision control” below) by control of the functional liquid crystal film, a countermeasure for reducing a burden of the driver who continuously keeps watching the virtual image to be three-dimensionally displayed in the HUD display regionin front of the windshieldhas been examined.

when the virtual image (≈distance to an object) is far (or close). when inclination of a face of the driver exceeds a predetermined threshold value. when a continuous driving time exceeds a predetermined threshold value. when brightness in a vehicle room is less than a predetermined threshold value. 35 when it is hard to keep a quality of parallax video image (for example, by adjusting the HUD display regionup and down, adjustment of the virtual image distance is not made in time when the virtual image reflected on a windshield having a large curvature is seen, and the like). when it is impossible to display the virtual image in a sense of distance corresponding to a distance to an object (for example, when the number of objects having different distances outside the adjustable region exceeds the number of independent virtual image distance adjustments, and the like). As a result of the examination, the following candidates have been provided as a scene (condition) of switching the size/shape of the eye box:

a size/shape of the eye box is changed so as to avoid direct sunlight (when not using, an entire region is made non-transparent, preventing an inside of the HUD from being heated by external light or reflection of the external light by the display screen). In addition to the above, the following is further provided:

35 36 FIGS.and Next, specific contents of the eye box control including the monocular vision/binocular vision control described above based on the examination results by the present inventors described above will be described in detail with reference to.

35 FIG. 260 illustrates a flow chart of process contents of the eye box control, and first, when the eye box control process starts, a determination result of a monocular vision/binocular vision suitability determination process described in detail below is taken in (S).

261 262 263 262 264 34 FIG.(a) 34 FIG.(b) Subsequently, based on the determination result described above, it is determined whether or not the monocular vision is suitable (S). When a result of this determination is “Yes,” it is further determined whether or not the monocular vision is set to the right eye (S). When a result of this determination is “Yes,” the eye box is changed such that the left eye is out of the eye box (S: see), and a series of processes ends. On the other hand, when the result of the determination in the step Sis “No,” the eye box is changed such that the right eye is out of the eye box (S: see), and a series of processes ends.

261 265 34 FIG.(c) Meanwhile, when the result of the determination in the step Sis “No,” the eye box is changed such that a size of the eye box is largest (S: see), and a series of processes ends.

260 36 FIG. Next, detailed contents of the monocular vision/binocular vision suitability determination process (S) described above will be determined in detail with reference to.

270 271 260 35 FIG. When the monocular vision/binocular vision suitability determination process starts, it is first determined whether or not difference in distance between the actual scenery (that is, the scenery seen through the windshield) and the virtual image (that is, the navigation display seen through the windshield) is a prescribed value or more (S). When a result of the determination is “Yes,” the single eye is suitably set (S), and a series of processes ends. Note that, as apparent from the above description, this setting is taken in as the determination result of the monocular vision/binocular vision suitability determination process in the process indicated in the step Sof.

270 272 271 271 Meanwhile, when the result of the determination process in the step Sdescribed above is “No,” it is further determined whether or not the inclination of the head of the driver is a prescribed value or more (S). When a result of the determination is “Yes,” the single eye is suitably set in the step Sdescribed above (S), and a series of processes ends.

272 273 271 271 On the other hand, when the result of determination process in the step Sdescribed above is “No,” it is further determined whether or not continuous time of the binocular vision is a prescribed value or more (S). When a result of the determination is “Yes,” the single eye is suitably set in the step Sdescribed above (S), and a series of processes ends.

273 274 271 On the other hand, when the result of determination process in the step Sdescribed above is “No,” it is further determined whether or not brightness in the vehicle room is a prescribed value or more (S). When a result of the determination is “Yes,” the single eye is suitably set similarly to the above (S), and a series of processes ends.

274 275 271 275 276 260 35 FIG. On the other hand, when the result of determination process in the step Sdescribed above is “No,” it is further determined whether or not the curvature of the front glass (windshield) of the virtual image reflected portion is a prescribed value or more (S). When a result of the determination is “Yes,” the single eye is suitably set (S), and a series of processes ends. On the other hand, when the result of the determination in the step Sis “No,” both eyes are suitably set (S), and a series of processes ends. Note that this setting is also taken in as the determination result of the monocular vision/binocular vision suitability determination process in the process indicated in the step Sof.

3 FIG. 115 116 Note that it is apparent for those skilled in the art that, in the above-described determination process, for example, the distance of the actual scenery and the inclination of the head of the driver as well as the brightness in the vehicle room can be easily obtained by using an acquisition device of the vehicle information illustrated indescribed above, such as the camera (inside the vehicle)and the camera (outside the vehicle).

As apparent from the above, according to the monocular vision/binocular vision control of the navigation information display described above, it is possible to achieve a head-up display apparatus capable of performing navigation information display enabling reduction of a burden of a driver even in driving for long hours.

20 21 3 5 FIGS.to Note that software for executing the monocular vision/binocular vision control of the navigation display described above is also, for example, stored in advance in the memory in the controllerconstituting the head-up display apparatus of the present invention to be executed by the ECU(see, for example), similarly to the above.

In the foregoing, the invention made by the present inventors has been concretely described based on the embodiments. However, it is needless to say that the present invention is not limited to the foregoing embodiments and various modifications and alterations can be made within the gist of the present invention. For example, the above-described embodiment has been described in detail so that the present invention is easily understood, and is not necessarily limited to the one including all configurations described. In addition, other configurations can be added to, deleted from, or replaced with the part of the configuration of each embodiment.

The present invention can be used to a head-up display apparatus using AR.

1 2 3 4 5 6 10 20 21 22 23 24 25 26 27 28 29 30 30 30 31 32 33 35 351 352 40 41 41 41 42 42 43 43 50 51 51 51 52 60 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 281 282 283 284 285 401 402 403 404 405 . . . AR-HUD,. . . vehicle,. . . windshield,. . . vehicle information,. . . driver,. . . display region,. . . vehicle information acquisition unit,. . . controller,. . . ECU,. . . audio output unit,. . . non-volatile memory,. . . memory,. . . light source adjusting unit,. . . distortion correction unit,. . . display element driver,. . . display distance adjusting unit,. . . mirror adjusting unit,. . . video image display,a . . . projector,b . . . LCD,. . . light source,. . . illumination optical system,. . . display element,. . . HUD display region,. . . navigation display (arrow),. . . arrow in a different mode,. . . display distance adjusting mechanism,a . . . diffuser,b . . . diffuser,c . . . movable diffuser,a . . . lens,b . . . movable lens,a . . . movable optical filter,b . . . comb-like optical filter,. . . mirror driver,. . . mirror,a . . . mirror,b . . . light control mirror,. . . mirror,. . . speaker,. . . vehicle speed sensor,. . . shift position sensor,. . . handle steering angle sensor,. . . headlight sensor,. . . illuminance sensor,. . . chromaticity sensor,. . . distance measuring sensor,. . . infrared ray sensor,. . . engine start sensor,. . . acceleration sensor,. . . gyro sensor,. . . temperature sensor,. . . road-to-vehicle communication wireless receiver,. . . vehicle-to-vehicle communication wireless receiver,. . . camera (inside the vehicle),. . . camera (outside the vehicle),. . . GPS receiver,. . . VICS receiver,. . . functional liquid crystal film ON/OFF controller,. . . lens movable unit,. . . light control mirror ON/OFF controller,. . . diffuser movable unit,. . . optical filter movable unit,. . . functional liquid crystal film,. . . lens movable mechanism,. . . light control mirror,. . . diffuser movable mechanism,. . . optical filter movable mechanism.