Display device

This Non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 106135764 filed in Taiwan, Republic of China on Oct. 18, 2017, the entire contents of which are hereby incorporated by reference.

This disclosure relates to a display device and, in particular, to a flat display device having power saving and local dimming functions.

With the development of technologies, flat display devices have been widely applied to various fields. Due to the advantages such as low power consumption, less weight, compact size and less radiation, the liquid crystal display (LCD) devices have gradually replaced the traditional cathode ray tube display (CRT) display devices and been applied to various electronic products, such as mobile phones, portable multimedia devices, notebook computers, liquid crystal TVs and liquid crystal screens.

Regarding the liquid crystal display (LCD) device, since the liquid crystal molecules cannot emit light by themselves, the backlight module is needed for outputting light, which passes through the LCD panel for displaying the image. Generally, when it is desired to show a black image on a part of the LCD panel, the control circuit of the display panel will control the switch elements corresponding to the region of the black image to block the light, so that the light cannot pass through the corresponding liquid crystal molecules, thereby generating the desired black image. However, the backlight module is still turned on when displaying the black image. Another method is to utilize a local dimming driving control circuit for partially turning on and partially turning off the backlight module so as to achieve the display of a black image on a part of the LCD panel.

However, in the above-mentioned first method, the backlight module continuously turns on to emit light, so the power consumption is higher. In the second method, the local dimming control circuit has a very complicated structure, which can increase the manufacturing cost. Accordingly, the conventional LCD device cannot achieve the local dimming, decrease the power consumption, and lower the cost at the same time.

An objective of the present disclosure is to provide a flat display device that has a simple structure and can decrease the power consumption and achieve the local dimming.

To achieve the above, the present disclosure provides a display device having a plurality of sub-pixels. The display device comprises a circuit substrate, a plurality of micro light-emitting semiconductor elements, a light conversion layer, and an opposite substrate. The micro light-emitting semiconductor elements are disposed separately on the circuit substrate and configured corresponding to the sub-pixels. The light conversion layer has a plurality of light conversion portions disposed respectively corresponding to at least partial of the micro light-emitting semiconductor elements. The light emitted from the micro light-emitting semiconductor element corresponding to each of the sub-pixels passes through the light conversion portion to generate white light. The opposite substrate is disposed at one side of the light conversion layer away from the circuit substrate.

In one embodiment, each of the micro light-emitting semiconductor elements has a side length greater than or equal to 1 μm and less than or equal to 100 μm.

In one embodiment, each of the micro light-emitting semiconductor elements emits blue light and green light at the same time.

In one embodiment, a thickness of the light conversion layer is greater than or equal to 6 μm and less than or equal to 30 μm.

In one embodiment, the light conversion layer comprises at least a light conversion substance, the light conversion substance is a quantum dot or a fluorescent particle, the quantum dot or the fluorescent particle is mixed within a paste material to form the light conversion layer, and the light conversion layer covers the micro light-emitting semiconductor elements.

In one embodiment, the circuit substrate is a matrix circuit substrate, the matrix circuit substrate comprises a substrate and a matrix circuit, the matrix circuit is disposed on the substrate, and the micro light-emitting semiconductor elements are disposed on the matrix circuit and electrically connected with the matrix circuit.

In one embodiment, the display device further comprises a black matrix layer disposed on the circuit substrate. The black matrix layer has a plurality of light-shielding regions, and the light-shielding regions are disposed around the micro light-emitting semiconductor elements to form the light conversion portions.

In one embodiment, the opposite substrate is a cover substrate, a monochrome filter substrate, or a color filter substrate.

In one embodiment, the color filter substrate comprises a transparent substrate and a plurality of filter portions, each of the filter portions is disposed between the transparent substrate and corresponding one of the light conversion portions, and the filter portions are disposed corresponding to the micro light-emitting semiconductor elements, respectively.

In one embodiment, the display device further comprises a transparent photoresist member disposed on the opposite substrate and covering at least one of the micro light-emitting semiconductor elements, and at least one of the micro light-emitting semiconductor elements emits blue light or green light.

In one embodiment, a part of the opposite substrate corresponding to the transparent photoresist member is not configured with a filter material.

In one embodiment, the display device further comprises a sealant layer disposed at outer peripheries of the circuit substrate and the opposite substrate.

To achieve the above, the present disclosure also provides a display device, which comprises a backlight module and a display panel. The backlight module comprises a circuit substrate, a plurality of micro light-emitting semiconductor elements, and a light conversion layer. The micro light-emitting semiconductor elements are disposed separately on the circuit substrate. The light conversion layer is disposed on the micro light-emitting semiconductor elements, and light emitted from the micro light-emitting semiconductor elements passes through the light conversion layer to generate white light. The display panel is disposed opposite to the backlight module.

In one embodiment, the light conversion layer comprises at least a light conversion substance, the light conversion substance is a quantum dot or a fluorescent particle, the quantum dot or the fluorescent particle is mixed within a paste material to form the light conversion layer, and the light conversion layer covers the micro light-emitting semiconductor elements.

In one embodiment, the light conversion layer is an optical film.

In one embodiment, the backlight module further comprises an opposite substrate, the opposite substrate is disposed between the light conversion layer and the display panel, and the opposite substrate is an optical film.

As mentioned above, the display device of this disclosure is configured with a light conversion layer on the micro light-emitting semiconductor elements, and the light conversion layer has a plurality of light conversion portions disposed respectively corresponding to at least partial of the micro light-emitting semiconductor elements. The light emitted from the micro light-emitting semiconductor element corresponding to each of the sub-pixels passes through the light conversion portion to generate white light. Alternatively, the display device of this disclosure comprises a display panel and a backlight module disposed opposite to each other, and the backlight module comprises a light conversion layer disposed on the micro light-emitting semiconductor elements. The light emitted from the micro light-emitting semiconductor elements passes through the light conversion layer to generate white light. Accordingly, the display device of this disclosure is different from the conventional flat display device, and the structure of the display device of this disclosure has simple structure and can decrease the power consumption and achieve the local dimming function. In some embodiments, the materials are easily prepared, and the manufacturing process is simpler. As a result, the display device of this disclosure has simpler structure and lower manufacturing cost.

The present disclosure will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.

In order to describe the structure of the display devices, the following top views of the embodiment only show the necessary components and the relations thereof, but do not show all of the components in the corresponding schematic diagrams.

1 FIG.A 1 FIG.B 1 FIG.A 1 1 FIGS.A andB 1 1 1 11 12 13 14 1 15 16 is a schematic diagram showing a display deviceaccording to an embodiment of this disclosure, andis a top view of. As shown in, the display deviceis a flat display device having a plurality of pixels, and each pixel has a plurality of sub-pixels P. The display devicecomprises a circuit substrate, a plurality of micro light-emitting semiconductor elements, a light conversion layer, and an opposite substrate. In addition, the display devicefurther comprises a black matrix layerand a sealant layer.

11 12 11 11 11 111 112 112 111 14 12 112 112 The circuit substratecan be an active matrix (AM) circuit substrate or a passive matrix (PM) circuit substrate, and the micro light-emitting semiconductor elementsare disposed separately on the surface of the circuit substrate. In this embodiment, the circuit substrateis an AM circuit substrate. The AM circuit substrate (circuit substrate) may comprise a substrateand a matrix circuit, and the matrix circuitis disposed on a surface of the substratefacing the opposite substrate. The micro light-emitting semiconductor elementsare disposed on the matrix circuitand electrically connected with the matrix circuit.

11 11 11 In practice, the substratecan be a flexible substrate or a rigid substrate, which is made by transparent or non-transparent material. The transparent material can be, for example, glass, quartz, sapphire or the likes, plastic, rubber, glass fiber, or other polymer materials. Preferably, the substratecan be an alumino silicate glass substrate, or it can be made of an organic polymer material. In some embodiments, the above organic polymer material is, for example but not limited to, polyimide (PI), polycarbonate (PC), or polyethylene terephthalate (PET). If the substrateis made of polyimide (PI), the glass transition temperature thereof can be, for example, between 400° C. and 600° C.

11 112 11 12 12 12 12 The circuit substrateof the present embodiment can be, for example, an AM circuit substrate of a LCD panel. The matrix circuitof the circuit substratemay include components such as interleaved data lines and scan lines, a plurality of active components (e.g. thin film transistors), a scan driving circuit, a data driving circuit, and a timing control circuit. One pixel P can correspond to one active component and at least one micro light-emitting semiconductor element, and each active component is electrically connected to at least one micro light-emitting semiconductor element. In practice, the scan lines can control the active elements, so that the data voltages transmitted via the data lines can be transmitted to the micro light-emitting semiconductor elementsthrough the switch elements for controlling the micro light-emitting semiconductor elementsto emit light. Since the AM circuit substrate is a well-known art of the LCD device, it is not the focus of the present disclosure, and those skilled in the art can find related technical content, so the details thereof will not be further described herein.

12 112 11 12 112 12 1 12 12 The micro light-emitting semiconductor elementsmay be arranged in an array and disposed on the matrix circuitof the circuit substrate. In some embodiments, the micro light-emitting semiconductor elementscan be electrically coupled to the matrix circuit, for example, by surface mount technology (SMT). The micro light-emitting semiconductor elementsof the present embodiment is exemplified by a micro light-emitting diode (μLED), and the display deviceis a μLED display device. The micro light-emitting semiconductor elementsof the present embodiment are arranged in a two-dimensional array. However, this disclosure is not limited thereto. In other embodiments, the micro light-emitting semiconductor elementsmay also be arranged in a one-dimensional array.

12 12 12 12 12 1 12 The micro light-emitting semiconductor elementsare respectively disposed corresponding to the sub-pixels P. In this embodiment, one micro light-emitting semiconductor elementmay correspond to one sub-pixel P, and this disclosure is not limited thereto. In other embodiments, multiple micro light-emitting semiconductor elementsmay correspond to one sub-pixel P. The side length of the micro light-emitting semiconductor elementmay be greater than or equal to 1 μm and less than or equal to 100 μm. In some embodiments, the side length of the micro light-emitting semiconductor elementcan be, for example, less than 50 μm (e.g. an element with a size of 25 μm×25 μm). Furthermore, the minimum pitch dof two adjacent micro light-emitting semiconductor elementsis, for example but not limited to, 1 μm, so that a display having a relatively high resolution, such as a medical display, can be manufactured.

12 12 121 122 12 12 12 12 1 12 112 11 12 1 The micro light-emitting semiconductor element(micro light-emitting diode) may be a two-electrode element or a three-electrode element. In this embodiment, the micro light-emitting semiconductor elementis a two-electrode element. The two electrodesandof the micro light-emitting semiconductor elementmay have the p-pole and the n-pole on the same side (horizontal structure), or the p-pole and the n-pole on the upper and lower sides respectively (vertical structure). In this embodiment, the micro light-emitting semiconductor elementis a μLED with a horizontally structured. In addition, if classified by color rendering wavelength, the micro light emitting semiconductor elementmay be a blue light-emitting diode, or a red light, green light, infrared light, or ultraviolet light (UV light) micro light-emitting diode, or a combination thereof. Alternatively, in different embodiments, the micro light-emitting semiconductor elementcan also emit blue light and green light at the same time, and this disclosure is not limited. Therefore, in the display deviceof the present embodiment, the micro light-emitting semiconductor elements(μLEDs) corresponding to the respective pixels P can be driven by the matrix circuitof the circuit substratein accordance with the display image with a partial black portion. Herein, some micro light-emitting semiconductor elementscorresponding to the partial black portion can be turned off. Accordingly, the display devicecan achieve the desired local dimming function, thereby achieving power saving.

13 12 2 13 13 131 12 131 12 131 131 131 12 131 131 The light conversion layeris disposed on the micro light-emitting semiconductor elements. The thickness dof the light conversion layermay be greater than or equal to 6 μm and less than or equal to 30 μm. In addition, the light conversion layerhas a plurality of light conversion portions, which are respectively disposed corresponding to at least a part of the micro light-emitting semiconductor elements. The light conversion portionsof the present embodiment are respectively disposed corresponding to the micro light-emitting semiconductor elements. The light conversion portionmay have a photoluminescence material. When the light enters the light conversion portion, the light conversion portioncan be excited to emit light with a different color. Specifically, the light emitted from the micro light-emitting semiconductor elementof the present embodiment enters the light conversion portion, and then the light conversion portion is excited to generate the light of a different color. Accordingly, the white light can be finally outputted from the light conversion portion.

131 13 131 12 131 131 12 131 131 131 The light conversion portionof the light conversion layermay have at least one light conversion substance, and the light conversion substance may be quantum dots or fluorescent particles. In this embodiment, the light conversion substance of the light conversion portioncomprises, for example, a quantum dot, and preferably comprises two quantum dots of different shapes or sizes for absorbing the high-energy light emitted from the micro light-emitting semiconductor elementto generate the visible light in different bandwidths. For example, two kinds of quantum dots can absorb high-energy blue or UV light to excite the low-energy red and green lights. Afterwards, the unabsorbed residual high-energy blue light and generated red and green lights outputted from the two kinds of excited quantum dots can be outputted from the light conversion portionand then mixed to form a white light. Alternatively, in another embodiment, the quantum dots of the light conversion portioncan absorb high-energy blue light and green light emitted from the micro light-emitting semiconductor elementto excite the low-energy red light. In this case, the light conversion portioncomprises only one size or shape of quantum dots, and the conversion efficiency of the light conversion portionis better. Afterwards, the unabsorbed residual high-energy blue light and green light and the excited red light are outputted from the light conversion portionand then mixed to form the white light.

12 112 13 151 15 12 131 131 12 151 15 12 3 14 151 15 14 To be noted, in practice, the above-mentioned light conversion substance (quantum dots or fluorescent particles) can be uniformly mixed in a paste material (e.g. epoxy) to form a jelly-type light conversion material, which can be applied to cover the micro light-emitting semiconductor elementsand the matrix circuit. Then, the jelly-type light conversion material is solidified to form the light conversion layer. In addition, the light-shielding regionsof the black matrix layerare disposed around each of the micro light-emitting semiconductor elementsto form the light conversion portions, thereby obtaining a plurality of sub-pixels P corresponding to the plurality of light conversion portionsand the plurality of micro light-emitting semiconductor elements. In this case, for example, one sub-pixel corresponds to one micro light-emitting semiconductor element. Of course, one sub-pixel may comprise a plurality of micro light-emitting semiconductor elements. It is to be noted that the light-shielding regionsof the black matrix layerof the present embodiment are disposed around each of the micro light-emitting semiconductor elements, and have a gap dfrom the opposite substrate. However, in different embodiments, each of the light-shielding regionsof the black matrix layercan also contact against the opposite substrate, and this disclosure is not limited thereto.

12 1 13 12 13 13 151 12 1 In addition, the conventional method cannot form the white light in the light conversion layer and output the white light from the light conversion layer (the colors of the lights corresponding to the pixels P are the same white light in the conventional art), but one sub-pixel P corresponds to one color of light (the colors of adjacent sub-pixels are different). Therefore, in the conventional method, the RGB pattern must be formed in the light conversion layer. That is, in order to emit RGB patterns of different colors, different kinds of light conversion substances must be separately formed on the micro light-emitting semiconductor elements. Thus, the full-color display can be produced without forming a color filter, so that the manufacturing process is complicated and the manufacturing cost is increased. However, in the display deviceof the present embodiment, the light conversion layerdoes not need to produce the light conversion portions having the RGB pattern corresponding to each of the light-emitting elements, respectively, but mixes the light conversion materials within the paste material, which is applied to cover the micro light-emitting semiconductor elementsto form the light conversion layer. Herein, the light conversion layeris partitioned by the light-shielding regionsto respectively form light conversion portions corresponding to the micro light-emitting semiconductor elements, respectively. The contents of the respective light conversion portions are the same. Therefore, the material preparation is easy, the manufacturing process is simple, the structure of the display deviceis simple, and the manufacturing cost is low.

14 13 11 13 14 11 13 131 15 11 131 151 15 131 12 131 12 15 The opposite substrateis disposed on one side of the light conversion layeraway from the circuit substrate. In this embodiment, the light conversion layeris sandwiched between the opposite substrateand the circuit substrate, and the single layer of the light conversion layeris divided into a plurality of light conversion portionsby the black matrix layeron the circuit substrate. Two light conversion portionsmay or may not be connected. Herein, the light-shielding regionsof the black matrix layerare disposed corresponding to the light conversion portionsof the sub-pixels P and the micro light-emitting semiconductor elements, such that one sub-pixel P corresponds to one light conversion portionand one micro light-emitting semiconductor element. The black matrix layerfunctions to avoid light mixing of adjacent sub-pixels, and the material thereof can be the same as the black matrix (BM) in the conventional LCD device. The details thereof will not be further described herein.

14 14 14 12 1 14 1 The opposite substratemay be a flexible substrate or a rigid substrate, and may be a protective substrate, a monochromatic filter substrate (e.g. a blue filter substrate), or a color filter substrate. The protective substrate may be a protective cover, a protective layer or a protective film, and this disclosure is not limited. In this embodiment, the opposite substrateis, for example, a light-permeable protective substrate, such as a glass substrate or a polymer transparent substrate. Furthermore, when the opposite substrateis a protective substrate or a monochromatic filter substrate, the effect of the monochrome display can be obtained by controlling the light-emission intensity of each of the micro light-emitting semiconductor elementscorresponding to each pixel P. In this case, the display devicecan be a monochrome display. In addition, when the opposite substrateis a color filter substrate, which includes, for example, the filter materials (R, G and B or R, B, and W), the display devicecan function as a full-color display. The details thereof will be described hereinbelow.

16 11 14 16 11 14 13 16 11 14 16 The sealant layeris disposed at the outer peripheries of the circuit substrateand the opposite substrate. In some embodiments, the sealant layermay be a light-curable adhesive (e.g. a UV adhesive), and is disposed at the outer peripheries of the circuit substrateand the opposite substrateby, for example but not limited to, a coating method under the atmosphere. Thus, the light conversion layercan be located within the sealant layer, the circuit substrateand the opposite substrate. In other embodiments, the sealant layermay also be a thermosetting adhesive or a combination of a light-curable adhesive and a thermosetting adhesive, and this disclosure is not limited.

2 FIG.A 2 FIG.B 2 FIG.A 1 1 FIGS.A andB 2 2 FIGS.A andB 1 1 14 1 14 141 142 142 141 131 142 12 is a schematic diagram showing a display devicea according to another embodiment of this disclosure, andis a top view of. Different from the display deviceof, as shown in, the opposite substrateof the display devicea is a color filter substrate instead of a protective substrate. In this embodiment, the color filter substrate (the opposite substrate) may comprise a transparent substrateand a plurality of filter portions. Each of the filter portionsis disposed corresponding to one sub-pixel P and located between the transparent substrateand the corresponding light conversion portion, and the filter portionsare disposed corresponding to the micro light-emitting semiconductor elements, respectively.

141 142 142 142 1 151 15 142 14 151 15 141 151 142 The transparent substratemay be a hard plate or a soft plate, and this disclosure is not limited. In this embodiment, the filter portionsinclude red (R), green (G) and blue (B) filter portions, which arranged in sequence and allow the red, green and blue lights to pass through. In different embodiments, the filter portionsmay include red (R), green (G), blue (B), and white (W) filter portions in sequence. Alternatively, if the colors of the filter portionsare all the same, the display device can be functioned as a monochrome display. The above-mentioned color filter substrate may be a color filter substrate (CF substrate) in a conventional LCD device, thereby making the display devicea to be a full-color display. In addition, the light-shielding regionsof the black matrix layerand the light-shielding regionson the opposite substrateof the present embodiment also have gaps therebetween. In different embodiments, the light-shielding regionsof the black matrix layermay extend and contact the transparent substraterespectively, so that a light-shielding regioncan be formed between two filter portions. This disclosure is not limited.

1 1 The other technical features of the display devicea can be referred to the same components of the display device, so the detailed descriptions thereof are not repeated.

3 FIG.A 3 FIG.B 3 FIG.A 2 2 FIGS.A andB 3 3 FIGS.A andB 1 1 1 17 17 17 141 14 12 12 142 12 12 141 131 17 141 12 14 17 131 12 17 141 1 131 is a schematic diagram showing a display deviceb according to another embodiment of this disclosure, andis a top view of. Different from the display devicea of, as shown in, the display deviceb further comprises a transparent photoresist member. For example, the material of the transparent photoresist membercan be the same as the material of the photo-spacers of the LCD panel, such as the photosensitive transparent photoresist materials (e.g. resins, silicates, or glass fibers). The transparent photoresist memberis disposed on the transparent substrateof the opposite substrateand covers at least one of the micro light-emitting semiconductor elements. At least one of the micro light-emitting semiconductor elementsemits blue light or green light. In this embodiment, the filter portionsincludes only the red filter portions and the green filter portions which are sequentially disposed, and do not include the blue filter portion. The reason of this configuration is that the micro light-emitting semiconductor elementsof the present embodiment can emit blue light. Thus, the blue light emitted from the micro light-emitting semiconductor elementcan directly pass through the transparent substrateto provide the desired blue light, and it is not necessary to provide the light conversion portionand the corresponding blue filter material. In other words, the transparent photoresist memberis disposed on the transparent substrateand covers the blue-light micro light-emitting semiconductor element, and the part of the opposite substratecorresponding to the transparent photoresist memberdoes not need to be configured with the blue filter portions (and the light conversion portions). The blue light emitted from the micro light-emitting semiconductor elementscan directly pass through the transparent photoresist memberand the transparent substrate, thereby making the display deviceb function as a full-color display. Accordingly, the material cost of the blue filter portion and the corresponding light conversion portioncan be saved.

17 141 141 17 12 12 131 12 12 17 12 14 11 2 2 FIGS.A andB In practice, the transparent photoresist membercan be correspondingly disposed on a part of the transparent substratewhere the blue filter portions are originally configured, and the transparent substratehaving the transparent photoresist memberis reversed and inserted to the position of the light conversion portion corresponding to the micro light-emitting semiconductor element, which can emit blue light, thereby squeezing out the light conversion material provided at this position. As shown in, the blue light emitted from the micro light-emitting semiconductor elementis absorbed by the light conversion substance in the light conversion portion. However, this embodiment does not configure the light conversion portion and the blue filter material, so that the current value input to the micro light-emitting semiconductor elementcan be relatively smaller (less than the current value of the micro light-emitting semiconductor elementscorresponding to the red filter portion and the green filter portion), and the brightness thereof can be relatively lower. Therefore, the configuration of the transparent photoresist membercan not only save the current value input to the micro light-emitting semiconductor elementsso as to decrease the power consumption, but also maintain the gap between the opposite substrateand the circuit substrate.

1 1 The other technical features of the display deviceb can be referred to the same components of the display devicea, so the detailed descriptions thereof are not repeated.

3 FIG.C 3 FIG.D 3 FIG.C 3 3 FIGS.A andB 3 3 FIGS.C andD 3 FIG.C 1 1 12 142 12 12 17 12 17 141 131 131 12 12 151 17 17 is a schematic diagram showing a display deviceb according to another embodiment of this disclosure, andis a top view of. Different from the display deviceb of, as shown in, the micro light-emitting semiconductor elementcorresponding to the red filter portionmay emit blue light or UV light, or simultaneously emit blue light and green light, the micro light-emitting semiconductor elementcorresponding to the position of the original green filter portion emits green light, and the micro light-emitting semiconductor elementcorresponding to the position of the original blue filter portion emits blue light. Therefore, the transparent photoresist memberis disposed at a position corresponding to the original green filter portion and the original blue filter portion, so that the green light and the blue light emitted from the micro light-emitting semiconductor elementscan pass through the transparent photoresist memberand then be output from the transparent substrate(the light does not pass through the light conversion portion, the green filter portion and the blue filter portion). This configuration can also make the display device function as a full-color display. Accordingly, not only the material costs of the blue filter portions and the green filter portions as well as the corresponding light conversion portionscan be saved, but also the total current value input to the micro light-emitting semiconductor elementscan be smaller because that the light conversion portion, the blue filter material and the green filter material are not provided. Thus, the current value input to the micro light-emitting semiconductor elementscan be saved to reduce more power consumption. In addition, as shown in, the light shielding regionbetween two transparent photoresist memberscompletely separates the transparent photoresist membersto avoid the light mixing of the green light and blue light emitted from two adjacent pixels P.

In the above embodiment, the design concept that the light emitted from the micro light-emitting semiconductor element passes through the light conversion layer to generate white light can also be applied to the backlight module of the flat display device.

4 FIG.A 4 FIG.B 4 FIG.A 4 FIG.B 2 21 is a schematic diagram showing a display deviceaccording to another embodiment of this disclosure, andis a top view of. To be noted,only shows the necessary components of the top view of the backlight module, and the other components are not shown.

4 4 FIGS.A andB 2 2 21 22 21 22 22 22 22 As shown in, the display deviceof the present embodiment is a flat display device such as, for example but not limited to, a liquid crystal display device. The display devicecan include a backlight moduleand a display panel. The backlight moduleis disposed opposite to the display paneland can emit light passing through the display panel, so that the display panelcan display an image. In this embodiment, the display panelis a liquid crystal display panel, such as, for example but not limited to, an in-plane switch (IPS) liquid crystal display panel, a fringe field switching (FFS) liquid crystal display panel, or a vertical alignment mode (VA mode) liquid crystal display panel, and this disclosure is not limited thereto.

21 211 212 213 212 212 211 211 211 2111 2112 212 2112 211 212 22 212 212 211 21 2 The backlight moduleis a direct-type backlight module, and includes a circuit substrate, a plurality of micro light-emitting semiconductor elements, and a light conversion layer. The micro light-emitting semiconductor elementof this embodiment is still exemplified by a micro light-emitting diode (μLED). The micro light-emitting semiconductor elementsare separately disposed on the circuit substrate. The circuit substratecan be a flexible circuit substrate or a rigid circuit substrate. The circuit boardof the present embodiment is, for example, a flexible circuit board, and may include a flexible substrateand a driving circuitfor driving the micro light-emitting semiconductor elements. Accordingly, the driving circuitof the circuit substratecan be used to control the micro light-emitting semiconductor elementsto emit light. Specifically, according to the display requirement of the display panel, the corresponding micro light-emitting semiconductor elementsare respectively turned on to emit light (or the partial micro light-emitting semiconductor elementsare not turned on) controlled by the driving of the circuit substrate. Therefore, the backlight moduleof the display devicecan achieve the local dimming effect.

2111 2111 In practice, the flexible substratecan be made by transparent or non-transparent material. The transparent material can be, for example, an organic polymer material. In some embodiments, the above organic polymer material is, for example but not limited to, polyimide (PI), polycarbonate (PC), or polyethylene terephthalate (PET). If the flexible substrateis made of polyimide (PI), the glass transition temperature thereof can be, for example, between 400° C. and 600° C.

213 212 212 213 213 212 2112 213 15 1 The light conversion layeris disposed on the micro light-emitting semiconductor elements. The light emitted from the micro light-emitting semiconductor elementspasses through the light conversion layerto generate white light. In some embodiments, the light conversion layercan comprise at least one light conversion substance, and the light conversion substance can be quantum dots or fluorescent particles. In practice, the quantum dots or the fluorescent particles may be mixed in the paste material to form a light conversion material, and the light conversion material may be coated to cover the micro light-emitting semiconductor elementsand the driving circuit, and then cured to form the light conversion layer. To be noted, the black matrix layerof the above display deviceis not provided in this embodiment.

213 212 213 213 212 213 In this embodiment, the light conversion substance of the light conversion layercomprises, for example, a quantum dot for absorbing the high-energy light emitted from the micro light-emitting semiconductor element. For example, the light conversion substance can absorb the high-energy blue or UV light to excite the low-energy red and green lights. Afterwards, the unabsorbed residual high-energy blue light and generated red and green lights can be outputted from the light conversion layerand then mixed to form a white light. Alternatively, in another embodiment, the quantum dots of the light conversion layercan absorb high-energy blue light and green light emitted from the micro light-emitting semiconductor elementto excite the low-energy red light. Afterwards, the unabsorbed residual high-energy blue light and green light and the excited red light are outputted from the light conversion layerand then mixed to form the white light.

21 214 214 213 22 21 24 211 214 24 211 214 213 24 211 214 24 In this embodiment, the backlight modulemay further include an opposite substrate. The opposite substratemay be a rigid or flexible plate and disposed between the light conversion layerand the display panel. In addition, the backlight moduleof the present embodiment may further include a sealant layerdisposed at the outer peripheries of the circuit substrateand the opposite substrate. In some embodiments, the sealant layermay be a light-curable adhesive (e.g. a UV adhesive), and is disposed at the outer peripheries of the circuit substrateand the opposite substrateby, for example but not limited to, a coating method under the atmosphere. Thus, the light conversion layercan be located within the sealant layer, the circuit substrateand the opposite substrate. In other embodiments, the sealant layermay also be a thermosetting adhesive or a combination of a light-curable adhesive and a thermosetting adhesive, and this disclosure is not limited.

21 23 22 214 21 23 23 213 214 23 22 In addition, the backlight moduleof the embodiment further includes at least one optical filmdisposed between the display paneland the opposite substrate. In some embodiments, the backlight moduleincludes a plurality of optical films, and the optical filmscan be, for example but not limited to, a diffusing plate, a 90° light collector, a 0° light collector, or a brightness enhancement film, or a combination thereof. Accordingly, the light outputted from the conversion layerpasses through the opposite substrateand the optical filmto form a more uniform surface light source, which is provided for the display panel.

23 22 214 23 214 23 214 22 213 23 214 214 To be noted, in different embodiments, the optical filmis not configured between the display paneland the opposite substrateso as to save the material cost of the optical film. Alternatively, this embodiment may not include the opposite substrate, and the optical filmcan be directly substitute the function of the opposite substrate. Accordingly, the interval between the display paneland the light conversion layeronly includes the optical film, so that the material cost of the opposite substratecan be saved. Alternatively, this embodiment may include an opposite substrate, which is an optical film itself. This configuration can also reduce the cost, and this disclosure is not limited.

5 6 7 FIGS.A,A and 5 FIG.B 5 FIG.A 6 FIG.B 6 FIG.A 5 6 FIGS.B andB 2 2 21 21 are schematic diagrams showing display devicesa-c according to different embodiments of this disclosure.is a top view of, andis a top view of. To be noted,only show the top views of backlight modulesa andb, respectively.

2 2 25 211 212 251 25 212 251 212 251 214 251 214 4 4 FIGS.A andB 5 5 FIGS.A andB Different from the display deviceof, as shown in, the display devicea further comprises a black matrix layerdisposed on the circuit substrateand located around the micro light-emitting semiconductor elements. In this embodiment, one light shielding regionof the black matrix layersurrounds one of the micro light-emitting semiconductor elementsto avoid light mixing. The light shielding regionsare disposed around the micro light-emitting semiconductor elements, respectively, and there is still a space between the light shielding regionsand the opposite substrate. In different embodiments, the light shielding regionsmay connect with the opposite substrate, and no gap is configured therebetween.

2 25 2 251 212 251 212 212 212 251 212 251 212 251 212 251 212 212 2112 212 5 5 FIGS.A andB 6 6 FIGS.A andB Different from the display devicea of, as shown in, in the black matrix layerof the display deviceb, one light shielding regionsurrounds multiple micro light-emitting semiconductor elements. In practice, one light shielding regionmay surround 2×2 micro light-emitting semiconductor elements, 2×3 micro light-emitting semiconductor elements, or 2×4 micro light-emitting semiconductor elements. The configuration of the light shielding regionsand the micro light-emitting semiconductor elementscan be determined based on the design requirement. In other words, it is unnecessary to provide one light shielding regionto surround one micro light-emitting semiconductor element, but to provide one light shielding regionto surround two or more micro light-emitting semiconductor elements. Since the configuration of the light shielding regionsand the micro light-emitting semiconductor elementsis adjustable, it is possible to control a block of micro light-emitting semiconductor elementsto emit light or not, thereby achieving the local dimming function. According to the above design, the driving circuitfor driving the micro light-emitting semiconductor elementsis simpler and has lower cost.

2 21 2 214 213 213 212 213 2 2 24 2 24 211 214 2 4 4 FIGS.A andB 7 FIG. Different from the display deviceof, as shown in, the backlight modulec of the display devicec is not configured with the opposite substrate, and the light conversion layeris an optical film (such as, for example but not limited to, a QD film). In practice, since the light conversion layeris an optical film, so that it can be manufactured by cutting a large-scaled optical film to obtain the optical film of the desired size, and the manufactured optical film of the desired size can be directly attached on the micro light-emitting semiconductor elements. Accordingly, the material preparation and manufacturing process of the light conversion layerbecome very easy, so that the structure of the display devicec can be simpler, and the manufacturing cost thereof can be decreased. In addition, the display devicec of this embodiment is not configured with the sealant layer. To be noted, in other embodiments, the display devicec may be configured with a sealant layerdisposed at the outer peripheries of the circuit substrateand the opposite substrate(referring to the display device).

2 2 2 The other technical features of the display devicesa-c can be referred to the same components of the display device, so the detailed descriptions thereof are not repeated.

In summary, the display device of this disclosure is configured with a light conversion layer on the micro light-emitting semiconductor elements, and the light conversion layer has a plurality of light conversion portions disposed respectively corresponding to at least partial of the micro light-emitting semiconductor elements. The light emitted from the micro light-emitting semiconductor element corresponding to each of the sub-pixels passes through the light conversion portion to generate white light. Alternatively, the display device of this disclosure comprises a display panel and a backlight module disposed opposite to each other, and the backlight module comprises a light conversion layer disposed on the micro light-emitting semiconductor elements. The light emitted from the micro light-emitting semiconductor elements passes through the light conversion layer to generate white light. Accordingly, the display device of this disclosure is different from the conventional flat display device, and the structure of the display device of this disclosure has simple structure and can decrease the power consumption and achieve the local dimming function. In some embodiments, the materials are easily prepared, and the manufacturing process is simpler. As a result, the display device of this disclosure has simpler structure and lower manufacturing cost.

Although the disclosure has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the disclosure.