Medium Conveyance Device, Control Method, and Control Program

This is a continuation application of U.S. continuation-in-part application Ser. No. 18/521,969, filed November 28,2023, which claims priority to and benefit of U.S. continuation-in-part of International Application No. PCT/JP2021/020730, filed on May 31, 2021, the entire contents of which are incorporated herein by reference.

The present disclosure relates to a medium conveying apparatus, a control method, and a control program and particularly relates to a medium conveying apparatus, a control method, and a control program for separating and sequentially feeding media.

In a medium conveying apparatus such as a scanner that separates and sequentially feeds a plurality of media to image, it is required to further reduce the time required for medium feeding. On the other hand, it is required for the medium conveying apparatus to temporarily stop medium feeding, for example, when there is insufficient free space in a storage device to store images of the media or when the distance between successively fed media is short. In such a case, the medium conveying apparatus is required to suitably control stoppage and resumption of medium feeding.

A sheet feeding device to control a feed roller to a low speed, when feeding of a succeeding sheet by the feed roller is started after arrival of the rear edge of a preceding sheet is detected by a post-registration sensor, is disclosed (see International Application Publication No. WO 2019/130648). The sheet feeding device controls the feed roller to a high speed when the front edge of the succeeding sheet passes a nip position of the feed roller and a separation roller.

According to some embodiments, a medium conveying apparatus includes a loading tray to place media, a feed roller to separate and sequentially feed the media placed on the loading tray, a motor to drive the feed roller, a sensor located on a downstream side of the feed roller in a medium conveying direction to detect a medium, and a processor to control the motor. In a separation period from a start of medium feeding by the feed roller to detection of a front edge of the first medium by the sensor, when feeding a first medium of a plurality of media placed on the loading tray, the control module controls the motor to rotate the feed roller at a constant speed, and when feeding a second or subsequent medium, the control module controls the motor to rotate the feed roller at a first speed and then at a second speed higher than the first speed.

According to some embodiments, a method for conveying a medium includes separating and sequentially feeding media placed on a loading tray by a feed roller, driving the feed roller by a motor, detecting a medium by a sensor located on a downstream side of the feed roller in a medium conveying direction, and controlling the motor. In a separation period from a start of medium feeding by the feed roller to detection of a front edge of the first medium by the sensor, when feeding a first medium of a plurality of media placed on the loading tray, controlling the motor to rotate the feed roller at a constant speed, and when feeding a second or subsequent medium, controlling the motor to rotate the feed roller at a first speed and then at a second speed higher than the first speed.

According to some embodiments, a computer-readable, non-transitory medium storing executable instructions for conveying a medium is provided. The executable instructions includes controlling a motor to drive a feed roller to separate and sequentially feed media placed on a loading tray. In a separation period from a start of medium feeding by the feed roller to detection of a front edge of the first medium by a sensor located on a downstream side of the feed roller in a medium conveying direction, when feeding a first medium of media placed on the loading tray, controlling the motor to rotate the feed roller at a constant speed, and when feeding a second or subsequent medium, controlling the motor to rotate the feed roller at a first speed and then at a second speed higher than the first speed.

The object and advantages of the invention will be realized and attained by means of the elements and combinations, in particular, described in the claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory, and are not restrictive of the invention as claimed.

Hereinafter, a medium conveying apparatus, a control method and a control program according to an embodiment, will be described with reference to the drawings. However, it should be noted that the technical scope of the invention is not limited to these embodiments, and extends to the inventions described in the claims and their equivalents.

is a perspective view illustrating an example of a medium conveying apparatus configured as an image scanner. The medium conveying apparatusconveys and images a medium being a document. Examples of a medium include paper, thick paper, a card, a booklet, and a passport. The medium conveying apparatusmay be a facsimile, a copying machine, a multifunctional peripheral (MFP), etc. A conveyed medium may be an object being printed on, etc., instead of a document, and the medium conveying apparatusmay be a printer, etc.

The medium conveying apparatusincludes a lower housing, an upper housing, a loading tray, an ejection tray, an operation device, a display device, etc.

The upper housingis located at a position covering the top surface of the medium conveying apparatusand is engaged with the lower housingby a hinge to be openable when, for example, a medium is stuck or cleaning of the inside of the medium conveying apparatusis performed.

The loading trayis engaged with the lower housingand places a medium to be fed and conveyed. The ejection trayis engaged with the upper housingand places an ejected medium. The ejection traymay be engaged with the lower housing.

The operation deviceincludes an input device such as a button, and an interface circuit acquiring a signal from the input device, accepts an input operation by a user, and outputs an operation signal based on the input operation by the user. The display deviceincludes a display including a liquid crystal, an organic electro-luminescence (EL), etc., and an interface circuit outputting image data to the display, and displays the image data on the display.

is a diagram for illustrating a conveyance path inside the medium conveying apparatus.

The conveyance path inside the medium conveying apparatusincludes a first medium sensor, a feed roller, a brake roller, a second medium sensor, an ultrasonic sensor, a third medium sensor, a fourth medium sensor, a fifth medium sensor, a conveyance roller, a first facing roller, a sixth medium sensor, an imaging device, an ejection roller, a second facing roller, etc.

Each of the numbers of the feed roller, the brake roller, the conveyance roller, the first facing roller, the ejection roller, and/or the second facing rolleris not limited to one and may be more than one. In that case, a plurality of feed rollers, brake rollers, conveyance rollers, first facing rollers, ejection rollers, and/or second facing rollersare respectively spaced in the width direction Aperpendicular to the medium conveying direction A.

The top surface of the lower housingforms a lower guideof the conveyance path of a medium, and the bottom surface of the upper housingforms an upper guideof the conveyance path of a medium. An arrow Ainindicates a medium conveying direction. Hereinafter, an upper stream refers to an upper stream in the medium conveying direction A, and a lower stream refers to a lower stream in the medium conveying direction A.

The first medium sensoris located on the upstream side of the feed rollerand the brake roller. The first medium sensorincludes a contact detection sensor and detects whether a medium is placed on the loading tray. The first medium sensorgenerates and outputs a first medium signal, the signal value of which varies between a state in which a medium is placed on the loading trayand a state in which a medium is not placed. The first medium sensoris not limited to a contact detection sensor and any other sensor that can detect existence of a medium, such as a light detection sensor, may be used as the first medium sensor.

The feed rolleris provided in the lower housing, separates and sequentially feeds media placed on the loading trayfrom the lower side. The brake rolleris provided in the upper housing, to face the feed roller, and rotates in a direction opposite to a medium feeding direction. The feed rollermay be provided in the upper housing, the brake rollermay be provided in the lower housing, and the feed rollermay sequentially feed media placed on the loading trayfrom the upper side.

The second medium sensoris an example of a second sensor, is located on the downstream side of the feed rollerand on the upstream side of the conveyance roller, and detects a medium conveyed to the position of the sensor. In particular, the second medium sensoris located between the feed rollerand the fifth medium sensorin the medium conveying direction Aand close to a nip region of the feed rollerand the brake roller. The second medium sensorincludes a light emitter and a light receiver that are provided on one side of the medium conveyance path and a light-guiding tube, provided at a position facing the light emitter and the light receiver with the medium conveyance path in between. The light emitter is a light emitting diode (LED), etc., and emits light toward the medium conveyance path. The light receiver is a photodiode, etc., and receives light emitted by the light emitter and guided by the light guide. When a medium is present at a position facing the second medium sensor, light emitted from the light emitter is blocked by the medium, and therefore the light receiver does not detect the light emitted from the light emitter. The second medium sensorgenerates and outputs a second medium signal, the signal value of which varies between a state in which a medium is present at the position of the second medium sensorand a state in which a medium is not present, based on the intensity of light received by the light receiver.

The ultrasonic sensoris an example of a thickness detection sensor. The ultrasonic sensoris located on the downstream side of the feed rollerand on the upstream side of the conveyance roller. The ultrasonic sensorincludes an ultrasonic transmitterand an ultrasonic receiver. The ultrasonic transmitterand the ultrasonic receiverare located close to the conveyance path of a medium to face each other with the conveyance path in between. The ultrasonic transmittertransmits an ultrasonic wave. The ultrasonic receiverreceives an ultrasonic wave transmitted by the ultrasonic transmitterand passing through a medium and generates and outputs an ultrasonic signal being an electric signal based on the received ultrasonic wave. When a plurality of media are conveyed in a stacked manner, an ultrasonic wave passing through the media is attenuated by an air layer between the media conveyed in a stacked manner. Accordingly, the medium ejection apparatuscan detect multi feed of media, based on the ultrasonic signal. Further, an ultrasonic wave passing through a medium is also attenuated by the medium itself, and an amount of attenuation increases as the thickness of the medium through which the ultrasonic wave passes increases. Accordingly, the medium ejection apparatuscan detect the thickness of the conveyed medium, based on the ultrasonic signal.

The fifth medium sensoris an example of a sensor, is located on the downstream side of the feed rollerand on the upstream side of the conveyance roller, and detects a medium conveyed to the position of the sensor. In other words, the fifth medium sensoris located between the feed rollerand the conveyance roller. The fifth medium sensorincludes a light emitter and a light receiver that are provided on one side of the medium conveyance path and a light-guiding tube, provided at a position facing the light emitter and the light receiver with the medium conveyance path in between. The light emitter is an LED, etc., and emits light toward the medium conveyance path. The light receiver is a photodiode, etc., and receives light emitted by the light emitter and guided by the light-guiding tube. The fifth medium sensorgenerates and outputs a fifth medium signal, the signal value of which varies between a state in which a medium is present at the position of the fifth medium sensorand a state in which a medium is not present, based on the intensity of light received by the light receiver.

The conveyance rollerand the first facing rollerare located on the downstream side of the feed rollerto face each other and convey a medium fed by the feed rollerand the brake rollerto the imaging device. The conveyance rolleris provided in the upper housing, and the first facing rolleris provided on the lower side of the conveyance rollerin the lower housing.

The sixth medium sensoris located on the downstream side of the conveyance rollerand on the upstream side of the imaging deviceand detects a medium conveyed to the position of the sensor. The sixth medium sensorincludes a light emitter and a light receiver that are provided on one side of the medium conveyance path and a lightguide, provided at a position facing the light emitter and the light receiver with the medium conveyance path in between. The light emitter is an LED, etc., and emits light toward the medium conveyance path. The light receiver is a photodiode, etc., and receives light emitted by the light emitter and guided by the light guide. The sixth medium sensorgenerates and outputs a sixth medium signal, the signal value of which varies between a state in which a medium is present at the position of the sixth medium sensorand a state in which a medium is not present, based on the intensity of light received by the light receiver.

The imaging deviceis an example of an imaging module, is located on the downstream side of the conveyance roller, and images a medium conveyed by the conveyance roller. The imaging deviceincludes a first imaging deviceand a second imaging devicethat are located to face each other with the medium conveyance path in between. The first imaging deviceincludes a line sensor based on a unity-magnification optical system type contact image sensor (CIS) including complementary metal oxide semiconductor-(CMOS-) based imaging elements linearly arranged in a main scanning direction. The first imaging devicefurther includes lenses each forming an image on an imaging element, and an A/D converter amplifying and analog-digital (A/D) converting an electric signal output from the imaging element. The first imaging devicegenerates an input image by imaging the front side of a conveyed medium in accordance with control from a processing circuit described later and outputs the generated image.

The second imaging deviceincludes a line sensor based on a unity-magnification optical system type CIS including CMOS-based imaging elements linearly arranged in the main scanning direction. The second imaging devicefurther includes lenses each forming an image on an imaging element, and an A/D converter amplifying and analog-digital (A/D) converting an electric signal output from the imaging element. The second imaging devicegenerates an input image by imaging the back side of a conveyed medium in accordance with control from the processing circuit described later and outputs the generated image.

Only one of the first imaging deviceand the second imaging devicemay be located and only one side of a medium may be read in the medium conveying apparatus. Further, a line sensor based on a unity-magnification optical system type CIS including charge coupled device- (CCD-) based imaging elements may be used in place of the line sensor based on a unity-magnification optical system type CIS including CMOS-based imaging elements. Further, a reduction optical system type line sensor including CMOS-based or CCD-based imaging elements may be used. The image sensors may be located to face each other, or may not be located to face each other.

The ejection rollerand the second facing rollerare located on the downstream side of the imaging deviceto face each other and eject a medium conveyed by the conveyance rollerand the first facing rollerand imaged by the imaging deviceinto the ejection tray. The ejection rolleris provided in the upper housing, and the second facing rolleris provided on the lower side of the ejection rollerin the lower housing.

A medium placed on the loading trayis conveyed between the lower guideand the upper guidetoward the medium conveying direction Aby the feed rollerrotating in a direction of an arrow Ain, i.e., the medium ejecting direction. The brake rollerrotates in a direction of an arrow A, i.e., a direction opposite to the medium feeding direction at the time of medium conveying. When a plurality of media are placed on the loading tray, only a medium in contact with the feed rollerof the medium placed on the loading trayis separated by working of the feed rollerand the brake roller. Consequently, conveyance of a medium other than the separated medium is restricted (prevention of multi feed). The brake rollermay separate the medium by stopping. A separation pad may be used in place of the brake roller.

A medium is fed between the conveyance rollerand the first facing rollerwhile being guided by the lower guideand the upper guide. The medium is fed between the first imaging deviceand the second imaging deviceby the conveyance rollerand the first facing rollerrotating in directions of an arrow Aand an arrow A, respectively. The medium read by the imaging deviceis ejected into the ejection trayby the ejection rollerand the second facing rollerrotating in directions of an arrow Aand an arrow A, respectively.

is a schematic diagram for illustrating driving sources of the feed roller, the brake roller, the conveyance roller, the first facing roller, the ejection roller, and/or the second facing roller.

As illustrated in, the medium conveying apparatusincludes a first motorand a second motoras driving sources of the rollers.

The first motoris an example of a motor, is provided in the lower housing, is connected to the feed rollerthrough a first transmission mechanism, and drives the feed roller. The first motorgenerates a driving force for driving the feed rollerin accordance with a control signal from a processing circuit. The first transmission mechanismincludes one or a plurality of pulleys, belts, gears, etc., that are provided between the first motorand a shaftof the feed rollerand transmits the driving force generated by the first motorto the feed roller. The first motorfeeds a medium by rotating the feed roller.

The second motoris provided in the upper housingseparately from the first motor, is connected to the conveyance roller, the ejection roller, and the brake rollerthrough a second transmission mechanism, and drives the conveyance roller, the ejection roller, and the brake roller. The second motorgenerates a driving force for driving the conveyance roller, the ejection roller, and the brake rollerin accordance with a control signal from the processing circuit. The second transmission mechanismincludes one or a plurality of pulleys, belts, gears, etc., that are provided between the second motor, and a shaftof the conveyance roller, a shaftof the ejection roller, and a shaftof the brake roller. In particular, one or a plurality of gears for changing the rotation direction and the rotation speed of each roller are provided between the shaftof the conveyance rollerand/or the shaftof the ejection roller, and the shaftof the brake roller. The second transmission mechanismtransmits the driving force generated by the second motorto the conveyance roller, the ejection roller, and the brake roller. The second motorcauses the conveyance roller, the ejection roller, and the brake rollerto feed, convey, and eject a medium by rotating the conveyance roller, the ejection roller, and the brake roller. The second motoris an example of a driving source of the brake roller.

The first facing rolleris a driven roller driven to rotate by the conveyance roller, and the second facing rolleris a driven roller driven to rotate by the ejection roller. The first facing rollerand/or the second facing rollermay be provided to be driven by the driving force from the second motor. In that case, one or a plurality of gears are further provided between the shaftof the conveyance rollerand the shaftof the first facing rollerand/or between the shaftof the ejection rollerand the shaftof the second facing roller. The second transmission mechanismfurther transmits the driving force generated by the second motorto the first facing rollerand/or the second facing roller.

andare schematic diagrams for illustrating the third medium sensorand the fourth medium sensor.is a schematic diagram of the lower guideof the lower housingviewed from above, andis a schematic diagram of the upper guideof the upper housingviewed from below.

As illustrated inand, the third medium sensorand the fourth medium sensorare located on the downstream side of the feed rollerand on the upstream side of the conveyance rollerand detect a medium conveyed to the positions of the sensors. In particular, the third medium sensorand the fourth medium sensorare located between the second medium sensorand the fifth medium sensorin the medium conveying direction A. The third medium sensorand the fourth medium sensormay be located at positions almost identical to that of the fifth medium sensorin the medium conveying direction A. Further, the third medium sensorand the fourth medium sensorare spaced in a width direction Aperpendicular to the medium conveying direction.

The third medium sensorincludes a light emitter and a light receiver that are provided on one side of the medium conveyance path and a light guide, provided at a position facing the light emitter and the light receiver with the medium conveyance path in between. The light emitter is an LED, etc., and emits light toward the medium conveyance path. The light receiver is a photodiode, etc., and receives light emitted by the light emitter and guided by the light guide. The third medium sensorgenerates and outputs a third medium signal, the signal value of which varies between a state in which a medium is present at the position of the third medium sensorand a state in which a medium is not present, based on the intensity of light received by the light receiver.

The fourth medium sensorincludes a light emitter and a light receiver that are provided on one side of the medium conveyance path and a light guide, provided at a position facing the light emitter and the light receiver with the medium conveyance path in between. The light emitter is an LED, etc., and emits light toward the medium conveyance path. the light receiver is a photodiode, etc., and receives light emitted by the light emitter and guided by the light guide. The fourth medium sensorgenerates and outputs a fourth medium signal, the signal value of which varies between a state in which a medium is present at the position of the fourth medium sensorand a state in which a medium is not present, based on the intensity of light received by the light receiver.

A reflection member such as a mirror may be used in place of the light guide in the second medium sensor, the third medium sensor, the fourth medium sensor, the fifth medium sensor, and/or the sixth medium sensor. Further, the light emitter and the light receiver may be provided to face each other with the medium conveyance path in between in the second medium sensor, the third medium sensor, the fourth medium sensor, the fifth medium sensor, and/or the sixth medium sensor. Further, each of the second medium sensor, the third medium sensor, the fourth medium sensor, the fifth medium sensor, and/or the sixth medium sensormay detect existence of a medium by, for example, a contact detection sensor to pass predetermined current when a medium is in contact or when a medium is not in contact. Further, each of the second medium sensor, the third medium sensor, the fourth medium sensor, the fifth medium sensor, and/or the sixth medium sensormay include an arm, a light emitter and a light receiver, to detect the medium. The arm is provided to be able to move by the medium being in contact with the arm. The light emitter and the light receiver may be provided to face each other with the arm in between. Each sensor generates and outputs a medium signal, the signal value of which varies between a state in which a medium is present at the position of each sensor and a state in which a medium is not present, based on the intensity of light received by the light receiver.

As illustrated in, the medium conveying apparatusincludes a first electromagnetic clutch. The first electromagnetic clutchis an example of an interruption mechanism and is provided on the shaftof the feed roller, i.e., on a driving force transmission path from the first motorto the feed roller. The first electromagnetic clutchis provided to be able to interrupt the driving force from the first motorto the feed rollerin accordance with a control signal from the processing circuit.

As illustrated in, the medium conveying apparatusincludes a second electromagnetic clutch. The second electromagnetic clutchis an example of an electromagnetic clutch and is provided on the shaftof the brake roller, i.e., on a driving force transmission path from the second motorbeing the driving source of the brake rollerto the brake roller. The second electromagnetic clutchis provided to be able to change the magnitude of torque exerted on the brake rollerin accordance with a control signal from the processing circuit.

is a block diagram illustrating a schematic configuration of an example of a medium conveying apparatus.

In addition to the configuration described above, the medium conveying apparatusfurther includes an interface device, a storage device, a processing circuit, etc.

For example, the interface deviceincludes an interface circuit conforming to a serial bus such as USB and transmits and receives an input image and various types of information by being electrically connected to an unillustrated information processing apparatus (such as a personal computer or a mobile information terminal). A communication device including an antenna transmitting and receiving wireless signals and a wireless communication interface circuit for transmitting and receiving signals through a wireless communication line in accordance with a predetermined communication protocol may be used in place of the interface device. For example, the predetermined communication protocol is a wireless local area network (LAN). The communication device may include a wired communication interface circuit for transmitting and receiving signals through a wired communication line in accordance with a communication protocol such as a wired LAN.

The storage deviceincludes a memory device such as a random-access memory (RAM) or a read-only memory (ROM), a fixed disk device such as a hard disk, a portable storage device such as a flexible disk or an optical disk, etc. Further, a computer program, a database, a table, etc., that are used for various types of processing in the medium conveying apparatusare stored in the storage device. The computer programs may be installed on the storage devicefrom a computer-readable, non-transitory portable storage medium by using a well-known set-up program, etc. The portable storage medium is, for example, a compact disc read-only memory (CD-ROM) or a digital versatile disc read-only memory (DVD-ROM).

The processing circuitoperates in accordance with a program previously stored in the storage device. For example, the processing circuit is a central processing unit (CPU). Examples of the processing circuitthat may also be used include a digital signal processor (DSP), a large scale integration (LSI), an application specific integrated circuit (ASIC), and a field-programmable gate array (FPGA).

The processing circuitis connected to the operation device, the display device, the first medium sensor, the second medium sensor, the ultrasonic sensor, the third medium sensor, the fourth medium sensor, the fifth medium sensor, the sixth medium sensor, the imaging device, the first motor, the second motor, the first electromagnetic clutch, the second electromagnetic clutch, the interface device, the storage device, etc., and controls the components. The processing circuitperforms drive control of the first motor, imaging control of the imaging device, etc., based on each medium signal received from each sensor, acquires an input image from the imaging device, and transmits the acquired image to the information processing apparatus through the interface device.

is a diagram illustrating a schematic configuration of an example of a storage device and a processing circuit.