JP2013047700A - Liquid crystal display device, illumination device unit, and solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device attaining power saving, and to provide an illumination device unit and a solar cell which are used in the liquid crystal display device.SOLUTION: A liquid crystal display device 10 includes: a liquid crystal panel 21 having a display surface 22; a backlight 61 that is arranged in an opposite side to a side in which the display surface 22 is formed with respect to the liquid crystal panel 21 and irradiates the liquid crystal panel 21 with illumination light; and a light-transmitting solar cell 31 which is arranged between the liquid crystal panel 21 and the backlight 61 and can transmit the illumination light that has been emitted from the backlight 61 toward the liquid crystal panel 21. The solar cell 31 has a photoelectric conversion layer 32 for performing photoelectric conversion using external light having transmitted through the liquid crystal panel 21, and a photoelectric conversion layer 42 for performing photoelectric conversion using the illumination light having been emitted from the backlight 61.

Description

  The present invention generally relates to a liquid crystal display device, a lighting device unit, and a solar cell, and more specifically, a liquid crystal display device including a solar cell, and a lighting device unit and a solar cell used in the liquid crystal display device. About.

  As a conventional example of a device equipped with a solar cell, for example, Japanese Patent Application Laid-Open No. 2005-310896 discloses a light source integrated solar cell module that achieves full light emission while minimizing a decrease in power generation efficiency. (Patent Document 1). The light source integrated solar cell module disclosed in Patent Document 1 houses a light-transmissive solar cell, an LED illumination device provided on the back side of the solar cell, the LED illumination device, and the back side of the solar cell. And a reflection plate covering the substrate. A solar cell generates electric power using sunlight incident from the surface side thereof. The LED light emitted from the LED illumination device is reflected by the reflector and then emitted from the back side of the solar cell to the front side.

  Japanese Patent Application Laid-Open No. 2007-171321 discloses an electro-optical device for the purpose of reliably reducing power consumption (Patent Document 2). In the electro-optical device disclosed in Patent Document 2, a solar battery cell including a photoelectric conversion element is provided in a display area of a liquid crystal panel.

  Japanese Patent Laid-Open No. 2006-41291 discloses a light emitting module that can prevent a decrease in the output of a solar cell without attenuating light incident on the solar cell, and can be manufactured more simply ( Patent Document 3). The light emitting module disclosed in Patent Document 3 includes a solar cell unit that generates power during the daytime and a light emitting unit that emits light when power is supplied.

  Japanese Patent Laid-Open No. 2006-120387 discloses a lighting device with a solar cell for the purpose of reducing the cost by a simple configuration while increasing the degree of freedom of arrangement of light emitting elements (Patent Document). 4). The solar cell-equipped lighting device disclosed in Patent Document 4 includes a non-transmissive integrated solar cell including a plurality of solar cells adjacent to each other, and an LED mounted on the back surface of the integrated solar cell.

JP 2005-310896 A JP 2007-171321 A JP 2006-41291 A JP 2006-120387 A

  Various devices provided with solar cells disclosed in Patent Documents 1, 3, and 4 are used for illumination devices such as outdoor lighting, light emitting signs, guide signs, and the like. According to these devices, light is emitted using the electric power generated by the solar cell, so that power saving of the device can be achieved. In addition, the electro-optical device including the solar cell unit disclosed in Patent Document 2 is used for a liquid crystal panel such as a mobile phone, a personal computer, or a digital still camera. The electric power generated in the solar cell unit is used to drive the liquid crystal panel device.

  However, in recent years, it has been demanded that the power consumption of the liquid crystal display device be significantly reduced as the liquid crystal panel becomes larger. In the electro-optical device disclosed in Patent Document 2, power saving is required. There is room for further improvement.

  Accordingly, an object of the present invention is to solve the above-described problems, and to provide a liquid crystal display device that can save power, and an illumination device unit and a solar cell used in the liquid crystal display device.

  A liquid crystal display device according to the present invention includes a liquid crystal panel having a display surface, and an illumination device that is disposed on the opposite side of the liquid crystal panel from the side on which the display surface is formed and that irradiates illumination light toward the liquid crystal panel And a light-transmitting solar cell that is disposed between the liquid crystal panel and the lighting device and is capable of transmitting the illumination light emitted from the lighting device toward the liquid crystal panel. The solar cell includes a first photoelectric conversion layer that performs photoelectric conversion using external light transmitted through the liquid crystal panel, and a second photoelectric conversion layer that performs photoelectric conversion using illumination light irradiated from the illumination device. .

  According to the liquid crystal display device configured in this way, by providing the first photoelectric conversion layer and the second photoelectric conversion layer in the solar cell, the external light transmitted from the liquid crystal panel side and the illumination irradiated from the illumination device side Electricity is generated using both light and light. By using the generated power as driving power for the liquid crystal display device, it is possible to save power in the liquid crystal display device.

  Preferably, the first photoelectric conversion layer and the second photoelectric conversion layer penetrate light in a direction connecting the illuminating device and the liquid crystal panel, and transmit the illumination light emitted from the illuminating device toward the liquid crystal panel. An opening in which the transmission layer is disposed is formed.

  According to the liquid crystal display device configured as described above, the illumination light irradiated from the illumination device is transmitted through the light transmission layer by forming the opening in which the light transmission layer is disposed in the first and second photoelectric conversion layers. Reach the LCD panel. Thereby, the illumination light irradiated from the illumination device can be efficiently delivered to the liquid crystal panel, and power saving of the illumination device can be achieved.

  Preferably, the lighting device has a light source that emits illumination light and is disposed immediately below the opening. According to the liquid crystal display device configured as described above, it is possible to efficiently reach the liquid crystal panel with the illumination light emitted from the illumination device. Thereby, the power saving of an illuminating device can be achieved.

  Preferably, the effective power generation region of the solar cell has a peripheral portion that overlaps the peripheral region of the display surface and a central portion that overlaps the central region of the display surface in a plan view when the display surface is viewed from the front. As for the aperture ratio of a 1st photoelectric converting layer and a 2nd photoelectric converting layer, the direction of a center part becomes larger than a peripheral part. In addition, the effective power generation area | region of a solar cell means the area | region which can produce electric power with a 1st photoelectric converting layer and a 2nd photoelectric converting layer.

  According to the liquid crystal display device configured as described above, by setting a larger aperture ratio of the photoelectric conversion layer in the central portion that overlaps the central region of the display surface that is easy for the user to perceive, luminance variation in the central region is reduced. Apparent display quality can be improved. Conversely, by reducing the aperture ratio of the photoelectric conversion layer at the peripheral portion that overlaps the peripheral region of the display surface that is difficult for the user to perceive, power generation using the photoelectric conversion layer is efficiently performed, and power saving of the liquid crystal display device Can be achieved.

  Preferably, the light transmission layer has a light diffusibility for diffusing light from the illumination device toward the liquid crystal panel. Preferably, the solar cell further includes a transparent substrate disposed between the first photoelectric conversion layer and the liquid crystal panel and having light transmittance. The transparent substrate is formed so as to have light diffusibility on the extension of the opening.

  According to the liquid crystal display device configured as described above, the luminance uniformity of the liquid crystal panel can be improved by diffusing light from the illumination device toward the liquid crystal panel in the light transmission layer or the transparent substrate.

  Preferably, the lighting device includes a light source that emits illumination light. The liquid crystal display device further includes a transflective reflector that is disposed between the light source and the solar cell and has light transmittance and can reflect light. According to the liquid crystal display device configured as described above, external light that has passed through the solar cell and entered the illumination device can be reflected by the transflective reflector and directed to the second photoelectric conversion layer. On the other hand, the illumination light emitted from the light source can be directed to the liquid crystal panel by passing through the transflective reflector. As a result, it is possible to improve the power generation efficiency of the second photoelectric conversion layer while maintaining the function of the illumination device that irradiates illumination light toward the liquid crystal panel.

  Preferably, the first photoelectric conversion layer and the second photoelectric conversion layer have the illumination device and the liquid crystal panel so that the first photoelectric conversion layer faces the liquid crystal panel and faces the second photoelectric conversion layer. Laminated in the direction of tying. According to the liquid crystal display device configured as described above, power saving of the liquid crystal display device can be achieved by power generation by the first photoelectric conversion layer and the second photoelectric conversion layer stacked on each other.

  Preferably, the liquid crystal display device further includes a distance holding unit that is provided so as to keep a constant distance between the liquid crystal panel and the solar cell and has light transmittance.

  According to the liquid crystal display device configured as described above, a certain distance is provided between the liquid crystal panel and the photoelectric conversion layer by the distance holding unit. Thereby, the illumination light irradiated from the illumination device and transmitted through the solar cell reaches the liquid crystal panel while overlapping in multiple directions. At this time, since the distance holding unit has light transparency, the progress of the illumination light is not hindered by the distance holding unit. For this reason, the brightness uniformity of the liquid crystal panel can be improved.

  Preferably, the first photoelectric conversion layer and the second photoelectric conversion layer penetrate light in a direction connecting the illuminating device and the liquid crystal panel, and transmit the illumination light emitted from the illuminating device toward the liquid crystal panel. An opening in which the transmission layer is disposed is formed. The distance holding unit has a column shape that extends from directly above the first photoelectric conversion layer toward the liquid crystal panel. An air layer is formed immediately above the opening.

  According to the liquid crystal display device thus configured, the illumination light irradiated from the illumination device and transmitted through the solar cell overlaps in multiple directions while traveling through the air layer, thereby improving the luminance uniformity of the liquid crystal panel. be able to. Furthermore, since an air layer is arrange | positioned between a solar cell and a liquid crystal panel, it can suppress that the heat which generate | occur | produced with the solar cell or the illuminating device is transmitted to a liquid crystal panel. Thereby, it is possible to prevent the display quality of the liquid crystal panel from being deteriorated due to the temperature change.

  Preferably, the distance holding unit is formed so as to enclose bubbles. Preferably, the distance holding unit includes a plurality of resin layers formed of a resin material, and a heat insulating layer interposed between the plurality of resin layers and arranged with air. Preferably, the distance holding unit has an uneven surface that forms a boundary with the air layer.

  According to the liquid crystal display device configured as described above, it is possible to suppress heat from being transmitted to the liquid crystal panel through the distance holding unit by increasing the heat insulating property of the distance holding unit. Thereby, it is possible to prevent the display quality of the liquid crystal panel from being deteriorated due to the temperature change.

  Preferably, the solar cell further includes a transparent substrate disposed between the first photoelectric conversion layer and the liquid crystal panel and having light transmittance. The distance holding unit is formed integrally with the transparent substrate. Preferably, the solar cell further includes a transparent electrode laminated on the first photoelectric conversion layer. The distance holding unit is formed integrally with the transparent electrode.

  According to the liquid crystal display device configured as described above, the distance holding unit can be formed with a simple configuration.

  Preferably, the distance holding unit has light diffusibility. According to the liquid crystal display device configured as described above, since the illumination light transmitted through the distance holding unit diffuses in multiple directions, the luminance uniformity of the liquid crystal panel can be further improved.

  Preferably, the lighting device includes a light source that emits illumination light, and a light guide layer that is provided so as to surround the light source and directs the light emitted from the light source to the liquid crystal panel. According to the thus configured liquid crystal display device, light emitted from the light source is directed to the liquid crystal panel as illumination light through the light guide layer.

  Preferably, the light source is composed of a light emitting diode. According to the liquid crystal display device configured as described above, the power consumption of the liquid crystal display device can be further reduced by reducing the power consumed by the light source.

  Preferably, the first photoelectric conversion layer and the second photoelectric conversion layer include an amorphous silicon layer and a microcrystalline silicon layer stacked on the amorphous silicon layer. According to the liquid crystal display device thus configured, the first and second photoelectric conversion layers are formed in a tandem structure including an amorphous silicon layer and a microcrystalline silicon layer.

  The illumination device unit according to the present invention is an illumination device unit used in a liquid crystal display device and combined with a liquid crystal panel. The illuminating device unit is disposed between the illuminating device that irradiates the illuminating light toward the liquid crystal panel and between the liquid crystal panel and the illuminating device, and can transmit the illuminating light emitted from the illuminating device toward the liquid crystal panel. A light transmissive solar cell. The solar cell includes a first photoelectric conversion layer that performs photoelectric conversion using external light transmitted through the liquid crystal panel, and a second photoelectric conversion layer that performs photoelectric conversion using illumination light irradiated from the illumination device. .

  According to the illuminating device unit configured in this way, by providing the solar cell with the first photoelectric conversion layer and the second photoelectric conversion layer, external light transmitted from the liquid crystal panel side and illumination irradiated from the illuminating device side Electricity is generated using both light and light. Thereby, the power saving of the liquid crystal display device in which the illumination device unit is used can be achieved.

  A solar cell according to the present invention is used in a liquid crystal display device, and is a solar cell disposed between a liquid crystal panel and an illumination device for irradiating illumination light toward the liquid crystal panel. The solar cell includes a transparent substrate having a surface and light transmittance, and a first photoelectric conversion layer and a second photoelectric conversion layer which are provided on the surface and stacked on each other. The first photoelectric conversion layer performs photoelectric conversion using external light transmitted through the liquid crystal panel, and the second photoelectric conversion layer performs photoelectric conversion using illumination light emitted from the illumination device.

  According to the solar cell configured as described above, by providing the first photoelectric conversion layer and the second photoelectric conversion layer in the solar cell, the external light transmitted from the liquid crystal panel side and the illumination light irradiated from the illumination device side To generate electricity. Thereby, the power saving of the liquid crystal display device using a solar cell can be achieved.

  As described above, according to the present invention, it is possible to provide a liquid crystal display device that can save power, and an illumination device unit and a solar cell that are used in the liquid crystal display device.

It is sectional drawing which shows the liquid crystal display device in Embodiment 1 of this invention. It is sectional drawing which shows the 1st modification of the liquid crystal display device in FIG. It is a top view which shows the 2nd modification of the liquid crystal display device in FIG. It is a top view which expands and shows the range enclosed by the dashed-two dotted line IV in FIG. It is a top view which expands and shows the range enclosed by the dashed-two dotted line V in FIG. It is sectional drawing which shows the 3rd modification of the liquid crystal display device in FIG. It is sectional drawing which shows the 4th modification of the liquid crystal display device in FIG. It is sectional drawing which shows the 5th modification of the liquid crystal display device in FIG. It is sectional drawing which shows the 6th modification of the liquid crystal display device in FIG. It is sectional drawing which shows the 7th modification of the liquid crystal display device in FIG. It is sectional drawing which shows the 8th modification of the liquid crystal display device in FIG. It is sectional drawing which shows the 1st modification of the distance holding | maintenance part shown in FIG. It is sectional drawing which shows the 2nd modification of the distance holding | maintenance part shown in FIG. It is sectional drawing which shows the 9th modification of the liquid crystal display device in FIG.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are denoted by the same reference numerals.

(Embodiment 1)
1 is a cross-sectional view showing a liquid crystal display device according to Embodiment 1 of the present invention. With reference to FIG. 1, first, the basic structure of the liquid crystal display device according to the first embodiment of the present invention will be described. The liquid crystal display device 10 according to the present embodiment includes a liquid crystal panel 21 having a display surface 22, A backlight 61 as an illuminating device that is disposed on the opposite side of the liquid crystal panel 21 from the side on which the display surface 22 is formed and irradiates illumination light toward the liquid crystal panel 21, and the liquid crystal panel 21 and the backlight 61 And a light transmissive solar cell 31 capable of transmitting the illumination light emitted from the backlight 61 toward the liquid crystal panel 21.

  The solar cell 31 performs photoelectric conversion using a photoelectric conversion layer 32 as a first photoelectric conversion layer that performs photoelectric conversion using external light transmitted through the liquid crystal panel 21 and illumination light emitted from the backlight 61. And a photoelectric conversion layer 42 as a second photoelectric conversion layer to be performed.

Next, the structure of the liquid crystal display device 10 in the present embodiment will be described in detail.
The liquid crystal display device 10 includes a liquid crystal panel 21 and a backlight 61. The liquid crystal panel 21 has a display surface 22 for displaying an image. The display surface 22 is formed so as to face the external space, and receives sunlight, light from indoor lighting in a room where the liquid crystal display device 10 is installed, and the like.

  The structure of the liquid crystal panel 21 is not specifically limited, A well-known liquid crystal panel can be used suitably. For example, the liquid crystal panel 21 includes an active matrix substrate on which a plurality of thin film transistors (TFTs) are formed, and a counter substrate disposed to face the active matrix substrate. The liquid crystal is sealed with a sealing member between the two.

  An optical member 26 and a transparent plate 27 are provided on the surface of the liquid crystal panel 21 opposite to the display surface 22. For example, the optical member 26 is optimal in accordance with the diffusion plate provided to alleviate the occurrence of a luminance difference in the light emitted from the backlight 61 in the area of the liquid crystal panel 21 and the usage pattern of the liquid crystal display device 10. It is provided by a combination of a diffusion sheet provided to supply orientation characteristics and a prism sheet provided to collect light in a specific direction. The transparent plate 27 is provided to protect the optical member 26.

  In addition, the optical member used for the backlight 61 is not limited to the above combination, and is appropriately changed according to the optical performance required for the liquid crystal display device 10.

  A backlight 61 is disposed on the back side of the liquid crystal panel 21 when the display surface 22 is viewed from the front. In the liquid crystal display device 10, the side on which the display surface 22 is arranged is the display side, and the side on which the backlight 61 is arranged is the back side. The backlight 61 is arranged at a distance from the liquid crystal panel 21. The backlight 61 has a function of illuminating the liquid crystal panel 21 from the back side.

  The backlight 61 includes a light emitting diode (LED) 62, an air layer 63, and a substrate 64.

  The LED 62 is provided as a light source that emits light. In the present embodiment, the LED 62 is formed by molding R, G, and B chips into one package. The LEDs 62 are provided on the surface of the substrate 64 at a distance from each other. By using a light emitting diode as the light source, the power consumption of the backlight 61 can be reduced and the life of the light source can be extended.

  A backlight reflector 65 is provided on the surface of the substrate 64 that forms a boundary with the air layer 63. The backlight reflector 65 functions as a reflective layer that can reflect the light emitted from the LED 62. The backlight reflecting plate 65 is formed by evaporating a metal such as aluminum on the surface of the substrate 64, for example.

  The air layer 63 is formed on the substrate 64. The air layer 63 is provided so as to surround the periphery of the LED 62. The air layer 63 has a function as a light guide layer that directs light emitted from the LEDs 62 to the liquid crystal panel 21.

  In the present embodiment, the air layer 63 is used as the light guide layer for directing the light emitted from the LEDs 62 to the liquid crystal panel 21, but the present invention is not limited to this, and a light guide plate may be used, for example. . The light guide plate is formed of a light-transmitting member. For example, a (meth) acrylic resin such as PMMA (methyl methacrylate resin), “ZEONOR” (registered trademark, manufactured by Nippon Zeon Co., Ltd.), etc. It is formed from a transparent resin such as COP (cycloolefin polymer), COC (cycloolefin copolymer), and polycarbonate.

  The liquid crystal display device 10 further includes a solar cell 31. The solar cell 31 is disposed between the liquid crystal panel 21 and the backlight 61. The solar cell 31 is provided adjacent to the backlight 61. The solar cell 31 includes a glass substrate 36 as a transparent substrate, photoelectric conversion layers 32 and 42, and electrodes 33, 34, 43, and 44.

The photoelectric conversion layers 32 and 42 have a function of generating power using the photoelectric effect.
In the present embodiment, the photoelectric conversion layers 32 and 42 are formed of a tandem thin film solar cell in which an amorphous silicon layer and a microcrystalline silicon layer are stacked. The amorphous silicon layer includes an a-Si: Hp layer, an a-Si: Hi layer, and an a-Si: Hn layer, and the microcrystalline silicon layer includes a μc-Si: Hp layer, a μc-Si: Hi layer, and a μc- Although it consists of a Si: Hn layer, it is not limited to this.

  The photoelectric conversion layers 32 and 42 which are thin film solar cells are produced by decomposing gaseous silicon by plasma discharge in a plasma CVD apparatus and laminating a thin silicon film on a glass substrate. In the case where thin film solar cells are used for the photoelectric conversion layers 32 and 42, the technology of the silicon thin film necessary for manufacturing the liquid crystal panel 21 can be applied horizontally to the manufacture of the solar cell 31, so that the liquid crystal display device 10 having the solar cell 31 is used. Can be produced efficiently.

  The photoelectric conversion layer 32 and the photoelectric conversion layer 42 are stacked on each other. The photoelectric conversion layer 32 and the photoelectric conversion layer 42 are stacked so as to overlap each other in a plan view of the liquid crystal display device 10 when the display surface 22 is viewed from the front. The photoelectric conversion layer 32 is disposed on the side facing the liquid crystal panel 21, that is, on the display side of the liquid crystal display device 10. The photoelectric conversion layer 42 is disposed on the side facing the backlight 61, that is, on the back side of the liquid crystal display device 10.

  Openings 40 are formed in the photoelectric conversion layers 32 and 42. The opening 40 is formed so as to penetrate the photoelectric conversion layers 32 and 42 in the direction connecting the liquid crystal panel 21 and the backlight 61. The opening 40 is formed to have the same cross-sectional shape at any position when cut by a plane orthogonal to the direction connecting the liquid crystal panel 21 and the backlight 61. The photoelectric conversion layers 32 and 42 are divided into a plurality of cells by the opening 40. In a plan view of the liquid crystal display device 10, the cells of the photoelectric conversion layers 32 and 42 are arranged in a matrix.

  In the present embodiment, an air layer 41 as a light transmission layer for transmitting the illumination light emitted from the backlight 61 toward the liquid crystal panel 21 is disposed in the opening 40. In addition, the light transmissive layer should just be a layer which has a light transmittance, for example, the transparent resin layer using said various transparent resin may be arrange | positioned in the opening part 40. FIG.

  The electrodes 33 and 34 are stacked on each cell of the photoelectric conversion layer 32, and the electrodes 43 and 44 are stacked on each cell of the photoelectric conversion layer 42. More specifically, the electrode 33 is laminated on each cell of the photoelectric conversion layer 32 from the display side of the liquid crystal display device 10. The electrode 34 is laminated on the photoelectric conversion layer 32 from the back side of the liquid crystal display device 10. The electrode 43 is laminated on each cell of the photoelectric conversion layer 42 from the back side of the liquid crystal display device 10. The electrode 44 is laminated on each cell of the photoelectric conversion layer 42 from the display side of the liquid crystal display device 10. The electrodes 34 and 44 are disposed between the photoelectric conversion layer 32 and the photoelectric conversion layer 42. The electrode 34 and the electrode 44 are disposed adjacent to each other while being electrically insulated from each other. The electrode 33 is disposed between the photoelectric conversion layer 32 and the liquid crystal panel 21, and the electrode 43 is disposed between the photoelectric conversion layer 42 and the backlight 61.

The electrodes 33 and 43 are provided as light-transmitting transparent electrodes, and are made of, for example, SnO ₂ (tin oxide). The electrodes 34 and 44 have a light shielding property, and are formed, for example, by laminating a ZnO (zinc oxide) layer and an Ag (silver) layer.

  In the present embodiment, the LED 62 is provided so as to be located immediately below the opening 40. The arrangement of the LEDs 62 is not limited to the above form, and for example, the LEDs 62 may be provided for every other opening 40, or may be provided so as to be located immediately below the cell of the photoelectric conversion layer 32. Good.

  The glass substrate 36 has optical transparency. The glass substrate 36 is disposed between the photoelectric conversion layer 32 and the liquid crystal panel 21. The glass substrate 36 is disposed at a distance from the liquid crystal panel 21, the optical member 26 and the transparent plate 27. The glass substrate 36 has a surface 37 extending in a direction orthogonal to the direction in which the liquid crystal panel 21 and the backlight 61 are connected. The electrode 33, the photoelectric conversion layer 32, the electrode 34, the electrode 44, the photoelectric conversion layer 42, and the electrode 43 are laminated on the surface 37 of the glass substrate 36 in the order given. The glass substrate 36 is provided so that the surface 37 faces the backlight 61.

  In addition, the board | substrate used for the solar cell 31 is not restricted to said glass substrate, It is a transparent substrate which has a light transmittance, Comprising: It is a board | substrate which has heat resistance which can endure the high temperature at the time of the manufacturing process of the solar cell 31. I just need it.

  The liquid crystal display device 10 further includes a distance holding unit 51. The distance holding unit 51 is provided so as to keep the distance between the liquid crystal panel 21 and the solar cell 31 constant. More specifically, the distance holding unit 51 is disposed between the liquid crystal panel 21 and the solar cell 31. The distance holding unit 51 is disposed between the liquid crystal panel 21 and the glass substrate 36. The distance holding unit 51 has a column shape extending from the solar cell 31 toward the liquid crystal panel 21. The distance holding unit 51 has a column shape that extends from directly above the cell of the photoelectric conversion layer 32 toward the liquid crystal panel 21. In the present embodiment, the distance holding unit 51 is provided corresponding to each cell of the photoelectric conversion layer 32.

  The distance holding unit 51 is formed so that the cross-sectional area decreases as the distance from the solar cell 31 toward the liquid crystal panel 21 increases. The distance holding unit 51 has a shape with a sharp tip on the liquid crystal panel 21 side. The distance holding unit 51 has a conical shape in which a vertex is disposed on the liquid crystal panel 21 side.

  The distance holding unit 51 is formed of a light transmissive member. In the present embodiment, the distance holding unit 51 is formed from the transparent resin exemplified above.

  An air layer 52 is formed between the liquid crystal panel 21 and the solar cell 31 by the distance holding unit 51 having such a configuration. The air layer 52 is formed immediately above the opening 40. The air layer 52 is formed in a space between the distance holding portions 51 adjacent to each other. The air layer 52 is formed so as to make a boundary with the transparent plate 27 and the glass substrate 36. The air layer 52 is formed so as to extend in a planar shape between the liquid crystal panel 21 and the solar cell 31 while having a certain thickness.

  The backlight unit 12 used as the illumination device unit used in the liquid crystal display device 10 and combined with the liquid crystal panel 21 includes a backlight 61 as an illumination device that irradiates illumination light toward the liquid crystal panel 21, and the liquid crystal panel 21 and the backlight unit. A light transmissive solar cell 31 that is disposed between the light 61 and capable of transmitting illumination light emitted from the backlight 61 toward the liquid crystal panel 21 is provided. The solar cell 31 performs photoelectric conversion using a photoelectric conversion layer 32 as a first photoelectric conversion layer that performs photoelectric conversion using external light transmitted through the liquid crystal panel 21 and illumination light emitted from the illumination device. And a photoelectric conversion layer 42 as a second photoelectric conversion layer.

  The solar cell 31 used in the liquid crystal display device 10 and disposed between the liquid crystal panel 21 and the backlight 61 for irradiating illumination light toward the liquid crystal panel 21 has a surface 37 and is light transmissive. A glass substrate 36 as a transparent substrate, a photoelectric conversion layer 32 as a first photoelectric conversion layer, and a photoelectric conversion layer 42 as a second photoelectric conversion layer, which are provided on the surface 37 and stacked on each other. The photoelectric conversion layer 32 performs photoelectric conversion using external light transmitted through the liquid crystal panel 21, and the photoelectric conversion layer 42 performs photoelectric conversion using illumination light emitted from the backlight 61.

  Then, the effect | action and effect which are show | played by the liquid crystal display device 10 in this Embodiment are demonstrated.

  First, irradiation of the liquid crystal panel 21 with illumination light will be described. Light emitted from the LED 62 passes through the air layer 63 and is irradiated toward the liquid crystal panel 21 as illumination light. At this time, the light traveling toward the back side of the liquid crystal display device 10 is reflected toward the liquid crystal panel 21 by the backlight reflector 65 functioning as a reflective layer. Illumination light emitted from the backlight 61 passes through the air layer 41 and further passes through the solar cell 31 by passing through the glass substrate 36 having optical transparency.

  The illumination light further passes through the air layer 52 and is irradiated toward the liquid crystal panel 21. At this time, the light reaches the liquid crystal panel 21 while overlapping in multiple directions in the air layer 52. In addition, since the distance holding unit 51 that forms the air layer 52 is light transmissive, light traveling in the air layer 52 is not blocked by the distance holding unit 51. In the liquid crystal display device 10 according to the present embodiment, since such illumination light is emitted toward the liquid crystal panel 21, the luminance uniformity in the liquid crystal panel 21 can be improved.

  In addition, the air layer 52 functions as a heat insulating layer interposed between the liquid crystal panel 21 and the solar cell 31. Thereby, it is possible to suppress the heat generated in the solar cell 31 or the backlight 61 from being transmitted to the liquid crystal panel 21. When heat is transmitted to the liquid crystal panel 21 and the temperature of the liquid crystal in the panel rises, the response of the liquid crystal changes. In the present embodiment, by suppressing the heat transfer to the liquid crystal panel 21, it is possible to prevent the display quality from being deteriorated due to the change in the response of the liquid crystal.

  Moreover, in this Embodiment, since the illumination light irradiated from the backlight 61 reaches | attains the liquid crystal panel 21 through the air layer 41, the structure which attaches the solar cell 31 with respect to the liquid crystal panel 21 is attained. For this reason, it is possible to maintain the display quality of the liquid crystal panel 21 without reducing the aperture ratio of the pixels in the liquid crystal panel 21 due to the provision of the solar cells 31.

  Next, the power generation action by illumination light and external light will be described. A part of the light emitted from the LED 62 goes to the electrode 43 through the air layer 63. The light passes through the electrode 43, which is a transparent electrode, and reaches the photoelectric conversion layer 42. On the other hand, external light that enters the liquid crystal panel 21 through the display surface 22 passes through the liquid crystal panel 21 and enters the air layer 52. External light that has passed through the air layer 52 and transmitted through the glass substrate 36 and the electrode 33 that is a transparent electrode reaches the photoelectric conversion layer 32. Thereby, power generation using illumination light is performed in the photoelectric conversion layer 42, and power generation using external light is performed in the photoelectric conversion layer 32.

  According to the liquid crystal display device 10 according to the first embodiment of the present invention configured as described above, the power generated by the photoelectric conversion layers 32 and 42 is used to emit light from the LEDs 62 in the backlight 61 and to the devices in the liquid crystal panel 21. Can be used for driving. Thereby, power saving of the liquid crystal display device 10 can be achieved.

  Note that the structure of the liquid crystal display device 10 in this embodiment is applied to various devices using a liquid crystal panel such as a liquid crystal television, but more preferably power consumption such as a large information display used as a digital signage. Is applied to large liquid crystal display devices.

(Embodiment 2)
In the present embodiment, various modifications of the liquid crystal display device 10 in FIG. 1 will be described. The liquid crystal display device in the present embodiment has basically the same structure as that of the liquid crystal display device 10 in the first embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

  FIG. 2 is a cross-sectional view showing a first modification of the liquid crystal display device in FIG. Referring to FIG. 2, the liquid crystal display device according to this modification includes a transflective reflector 66. The transflective reflector 66 is formed so as to be light transmissive and reflect light. More specifically, the transflective reflector 66 is made of a plate material that can reflect light, such as an aluminum plate. The transflective reflector 66 has a plurality of holes 67 penetrating in the thickness direction.

  The transflective reflector 66 is disposed between the LED 62 and the solar cell 31. The transflective reflector 66 is disposed so as to extend in a plane in a direction orthogonal to the direction connecting the liquid crystal panel 21 and the backlight 61 so as to block between the LED 62 and the solar cell 31. The transflective reflector 66 is disposed at a position spaced from both the LED 62 and the photoelectric conversion layer 42.

  According to such a configuration, the light emitted from the LED 62 and emitted to the air layer 63 passes through the hole 67 and passes through the transflective reflector 66. The light reflected on the surface of the transflective reflector 66 is reflected again by the backlight reflector 65 and travels toward the transflective reflector 66. Part of the illumination light transmitted through the transflective reflector 66 is irradiated to the liquid crystal panel 21 through the air layer 41, and the remaining part contributes to power generation in the photoelectric conversion layer 42.

  Further, part of the external light that enters the liquid crystal panel 21 through the display surface 22 travels to the backlight 61 through the air layer 41. In the present embodiment, such external light is reflected by the transflective reflector 66, thereby contributing to power generation in the photoelectric conversion layer 42. Thereby, the power generation efficiency in the solar cell 31 can be improved.

  According to the liquid crystal display device according to the second embodiment of the present invention configured as described above, the effects described in the first embodiment can be similarly obtained.

(Embodiment 3)
In the present embodiment, various modifications of the liquid crystal display device 10 in FIG. 1 will be described. The liquid crystal display device in the present embodiment has basically the same structure as that of the liquid crystal display device 10 in the first embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

  FIG. 3 is a plan view showing a second modification of the liquid crystal display device in FIG. In the figure, a plan view of the photoelectric emission layers 32 and 42 constituting the solar cell 31 in FIG. 1 is shown. 4 is an enlarged plan view showing a range surrounded by a two-dot chain line IV in FIG. FIG. 5 is an enlarged plan view showing a range surrounded by a two-dot chain line V in FIG.

  Referring to FIGS. 3 to 5, an effective power generation region 110, which is a region where the photoelectric light emitting layers 32 and 42 are arranged, and is a region where power can be generated by the photoelectric light emitting layers 32 and 42, is shown. Has been. The effective power generation region 110 includes a central portion 113 and a peripheral portion 112. The central portion 113 is disposed so as to overlap the central region of the display surface 22 in FIG. The peripheral portion 112 is disposed so as to overlap the peripheral region of the display surface 22 in FIG. The peripheral edge 112 extends annularly around the central part 113.

  In FIG. 3, the central portion 113 having a substantially rectangular planar shape is shown, but the present invention is not limited to this, and the central portion 113 may have a planar shape such as a circle.

  In this modification, the aperture ratio of the photoelectric conversion layers 32 and 42 in the effective power generation region 110 of the solar cell 31 is larger in the central portion 113 than in the peripheral portion 112. That is, the area of the opening 40 formed per unit area is larger in the central portion 113 than in the peripheral portion 112. In a state where the cells of the photoelectric conversion layers 32 and 42 are arranged in a matrix, the pitch L1 between the cells in the central portion 113 is larger than the pitch L2 between the cells in the peripheral portion 112.

  According to such a configuration, the amount of light emitted from the backlight 61 toward the liquid crystal panel 21 through the opening 40 is larger in the central portion 113 than in the peripheral portion 112. Since the viewer of the liquid crystal display device tends to perceive the image of the central portion rather than the peripheral portion of the display surface 22, according to this modification, the luminance variation in the central portion is reduced and the apparent display is achieved. Quality can be improved.

  According to the liquid crystal display device according to the third embodiment of the present invention configured as described above, the effects described in the first embodiment can be similarly obtained.

(Embodiment 4)
In the present embodiment, various modifications of the liquid crystal display device 10 in FIG. 1 will be described. The liquid crystal display device in the present embodiment has basically the same structure as that of the liquid crystal display device 10 in the first embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

  FIG. 6 is a cross-sectional view showing a third modification of the liquid crystal display device in FIG. Referring to FIG. 6, the liquid crystal display device according to this modification includes a distance holding unit 71 instead of distance holding unit 51 in FIG. 1. In this modification, the distance holding unit 71 is formed integrally with the glass substrate 36. That is, the distance holding unit 71 is made of glass.

  According to such a configuration, by forming the distance holding unit 71 integrally with the glass substrate 36 constituting the solar cell 31, it is possible to improve the luminance uniformity in the liquid crystal panel 21 while reducing the number of components. .

  FIG. 7 is a cross-sectional view showing a fourth modification of the liquid crystal display device in FIG. With reference to FIG. 7, in this modification, a glass substrate 36 is disposed between the photoelectric conversion layer 42 and the backlight 61. The glass substrate 36 is provided so that the surface 37 faces the liquid crystal panel 21. On the surface 37, the electrode 43, the photoelectric conversion layer 42, the electrode 44, the electrode 34, the photoelectric conversion layer 32, and the electrode 33 are laminated | stacked in order.

  The liquid crystal display device in this modification has a glass plate 76 as a distance holding unit instead of the distance holding unit 51 in FIG. The glass plate 76 is made of glass and has light transmittance. The glass plate 76 is provided in contact with the electrode 33 and the transparent plate 27. The glass plate 76 is formed so as to extend in a flat shape while having a certain thickness between the liquid crystal panel 21 and the solar cell 31.

  In such a configuration, the illumination light transmitted through the solar cell 31 is further transmitted through the glass plate 76 and irradiated toward the liquid crystal panel 21. At this time, since the light reaches the liquid crystal panel 21 while overlapping in multiple directions on the glass plate 76, the luminance uniformity in the liquid crystal panel 21 can be improved.

  FIG. 8 is a cross-sectional view showing a fifth modification of the liquid crystal display device in FIG. Referring to FIG. 8, in this modified example, a glass substrate 36 is provided so that the surface 37 faces the liquid crystal panel 21 as in the modified example shown in FIG. 7.

The liquid crystal display device in this modification has a distance holding unit 78 instead of the distance holding unit 51 in FIG. In this modification, the distance holding portion 78 is formed integrally with the electrode 33 that is a transparent electrode. That is, the distance holding unit 78 is made of SnO ₂ (tin oxide). The distance holding unit 78 has a cylindrical shape extending from the solar cell 31 toward the liquid crystal panel 21.

  According to such a configuration, by forming the distance holding portion 78 integrally with the electrode 33 constituting the solar cell 31, it is possible to improve the luminance uniformity in the liquid crystal panel 21 while reducing the number of components.

  According to the liquid crystal display device according to the fourth embodiment of the present invention configured as described above, the effects described in the first embodiment can be obtained similarly.

(Embodiment 5)
In the present embodiment, various modifications of the liquid crystal display device 10 in FIG. 1 will be described. The liquid crystal display device in the present embodiment has basically the same structure as that of the liquid crystal display device 10 in the first embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

FIG. 9 is a sectional view showing a sixth modification of the liquid crystal display device in FIG. Referring to FIG. 9, in this modification, the distance holding unit 51 has light diffusibility. More specifically, scattering particles 81 that scatter light emitted from the LEDs 62 are dispersed in the transparent resin forming the distance holding unit 51. As the scattering particles 81, for example, TiO ₂ , SiO ₂ , alumina, aluminum nitride, or mullite powder (particle size is, for example, 10 nm to 10 μm) can be used.

  According to such a configuration, since the light transmitted through the distance holding unit 51 is diffused by the scattering particles 81, the luminance unevenness of the illumination light irradiated on the liquid crystal panel 21 can be further reduced.

  FIG. 10 is a cross-sectional view showing a seventh modification of the liquid crystal display device in FIG. Referring to FIG. 10, in this modification, the glass substrate 36 is formed so as to have light diffusibility on the extension of the opening 40. More specifically, scattering particles 82 that scatter light emitted from the LEDs 62 are dispersed in the glass forming the glass substrate 36. The scattering particles 82 are provided at the position of the glass substrate 36 that overlaps the opening 40 in a plan view of the liquid crystal display device. As the scattering particles 82, the above-described various powders can be used.

  According to such a configuration, since the light passing through the glass substrate 36 is diffused by the scattering particles 82, the same effect as described above can be obtained.

  According to the thus configured liquid crystal display device in the fifth embodiment of the present invention, the effects described in the first embodiment can be similarly obtained.

(Embodiment 6)
In the present embodiment, various modifications of the liquid crystal display device 10 in FIG. 1 will be described. The liquid crystal display device in the present embodiment has basically the same structure as that of the liquid crystal display device 10 in the first embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

  FIG. 11 is a cross-sectional view showing an eighth modification of the liquid crystal display device in FIG. In the figure, the range surrounded by the two-dot chain line XI in FIG. 1 is shown enlarged. Referring to FIG. 11, in the present modification, a large number of bubbles 56 are formed inside the transparent resin that forms distance holding portion 51.

  According to such a configuration, since the air forming the bubbles 56 has a lower thermal conductivity than the resin material, the heat insulation of the distance holding unit 51 can be improved. Thereby, it can suppress more effectively that the heat which generate | occur | produced in the solar cell 31 or the backlight 61 is transmitted to the liquid crystal panel 21 through the distance holding | maintenance part 51. FIG.

  FIG. 12 is a cross-sectional view showing a first modification of the distance holding unit shown in FIG. Referring to FIG. 12, distance holding unit 51 has a surface 57 that forms a boundary with air layer 52 in FIG. 1. The surface 57 is formed to have a fine uneven shape.

  According to such a configuration, an air layer is formed in the concave portion 58 formed on the surface 57, so that the heat insulation of the distance holding unit 51 can be improved. Thereby, the effect similar to the modification shown in FIG. 11 can be acquired.

  FIG. 13 is a sectional view showing a second modification of the distance holding unit shown in FIG. Referring to FIG. 13, in the present modification, distance holding unit 51 has a multilayer structure including resin layer 51m, heat insulating layer 59, and resin layer 51n. The resin layer 51m and the resin layer 51n are made of a transparent resin. The heat insulation layer 59 is formed by enclosing air between the resin layer 51m and the resin layer 51n.

  According to such a configuration, the heat insulating property of the distance holding unit 51 can be enhanced by the arrangement of the heat insulating layer 59 in which air is enclosed. Thereby, the effect similar to the modification shown in FIG. 11 can be acquired.

  According to the thus configured liquid crystal display device in the sixth embodiment of the present invention, the effects described in the first embodiment can be obtained in the same manner.

(Embodiment 7)
In the present embodiment, various modifications of the liquid crystal display device 10 in FIG. 1 will be described. The liquid crystal display device in the present embodiment has basically the same structure as that of the liquid crystal display device 10 in the first embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

  FIG. 14 is a cross-sectional view showing a ninth modification of the liquid crystal display device in FIG. Referring to FIG. 14, in this modification, a transparent resin layer 45 is disposed in opening 40 instead of air layer 41 in FIG. 1. The transparent resin forming the transparent resin layer 45 is as described in the first embodiment. The transparent resin layer 45 has light diffusibility for diffusing light from the backlight 61 toward the liquid crystal panel 21. More specifically, scattering particles 83 that scatter light emitted from the LEDs 62 are dispersed in the transparent resin that forms the transparent resin layer 45. The powder forming the scattering particles 83 is as described in the fifth embodiment.

  According to such a configuration, since the light transmitted through the transparent resin layer 45 is diffused by the scattering particles 83, the luminance unevenness of the illumination light irradiated on the liquid crystal panel 21 can be further reduced.

  According to the liquid crystal display device according to the seventh embodiment of the present invention configured as described above, the effects described in the first embodiment can be obtained similarly.

  In addition, you may comprise a new liquid crystal display device combining the structure of the liquid crystal display device in Embodiment 1-7 demonstrated above suitably.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is mainly applied to a large-sized liquid crystal display device which is used in a place where the surroundings are bright and suitable for power generation and which consumes a large amount of power.

  DESCRIPTION OF SYMBOLS 10 Liquid crystal display device, 12 Backlight unit, 21 Liquid crystal panel, 22 Display surface, 26 Optical member, 27 Transparent plate, 31 Solar cell, 32, 42 Photoelectric conversion layer, 33, 34, 43, 44 Electrode, 36 Glass substrate, 37, 57 Surface, 40 Opening, 41 Air layer, 45 Transparent resin layer, 51 Distance holding unit, 51 m, 51 n Resin layer, 52, 63 Air layer, 56 Air bubble, 58 Recess, 59 Thermal insulation layer, 61 Back light, 64 Substrate, 65 Backlight reflector, 66 Transflective reflector, 67 holes, 71 Distance holder, 76 Glass plate, 78 Distance holder, 81, 82, 83 Scattered particles, 110 Effective power generation area, 112 Perimeter, 113 Center.

Claims (21)

A liquid crystal panel having a display surface;
An illuminating device that is disposed on the opposite side of the liquid crystal panel from the side on which the display surface is formed, and irradiates illumination light toward the liquid crystal panel;
A light transmissive solar cell that is disposed between the liquid crystal panel and the lighting device and capable of transmitting illumination light emitted from the lighting device toward the liquid crystal panel;
The solar cell includes a first photoelectric conversion layer that performs photoelectric conversion using external light transmitted through the liquid crystal panel, and a second photoelectric conversion layer that performs photoelectric conversion using illumination light irradiated from the illumination device. A liquid crystal display device.   The first photoelectric conversion layer and the second photoelectric conversion layer pass through in a direction connecting the illumination device and the liquid crystal panel, and transmit illumination light emitted from the illumination device toward the liquid crystal panel. The liquid crystal display device according to claim 1, wherein an opening in which the light transmission layer is disposed is formed.   The liquid crystal display device according to claim 2, wherein the illumination device has a light source that emits illumination light and is disposed immediately below the opening. The effective power generation region of the solar cell has a peripheral portion that overlaps a peripheral region of the display surface in a plan view when the display surface is viewed from the front, and a central portion that overlaps a central region of the display surface,
4. The liquid crystal display device according to claim 2, wherein an aperture ratio of the first photoelectric conversion layer and the second photoelectric conversion layer is larger in the central portion than in the peripheral portion.   5. The liquid crystal display device according to claim 2, wherein the light transmission layer has a light diffusibility for diffusing light from the illumination device toward the liquid crystal panel. 6. The solar cell further includes a transparent substrate disposed between the first photoelectric conversion layer and the liquid crystal panel and having light transmittance,
The liquid crystal display device according to claim 2, wherein the transparent substrate is formed so as to have light diffusibility on an extension of the opening. The illumination device has a light source that emits illumination light,
7. The liquid crystal display device according to claim 1, further comprising a transflective reflector that is disposed between the light source and the solar cell and has light transmissivity and can reflect light.   The first photoelectric conversion layer and the second photoelectric conversion layer include the lighting device and the lighting device such that the first photoelectric conversion layer faces the liquid crystal panel and the second photoelectric conversion layer faces the lighting device. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is laminated in a direction connecting to the liquid crystal panel.   9. The liquid crystal display device according to claim 1, further comprising a distance holding portion that is provided so as to keep a constant distance between the liquid crystal panel and the solar cell and has light transmittance. The first photoelectric conversion layer and the second photoelectric conversion layer pass through in a direction connecting the illumination device and the liquid crystal panel, and transmit illumination light emitted from the illumination device toward the liquid crystal panel. An opening in which the light transmission layer is disposed is formed,
The distance holding unit has a column shape extending from directly above the first photoelectric conversion layer toward the liquid crystal panel,
The liquid crystal display device according to claim 9, wherein an air layer is formed immediately above the opening.   The liquid crystal display device according to claim 10, wherein the distance holding unit is formed so as to enclose bubbles.   The distance holding portion is formed with a plurality of resin layers formed of a resin material and a heat insulating layer interposed between the plurality of resin layers and arranged with air. The liquid crystal display device described.   The liquid crystal display device according to claim 10, wherein the distance holding unit has an uneven surface that forms a boundary with the air layer. The solar cell further includes a transparent substrate disposed between the first photoelectric conversion layer and the liquid crystal panel and having light transmittance,
The liquid crystal display device according to claim 10, wherein the distance holding unit is formed integrally with the transparent substrate. The solar cell further includes a transparent electrode laminated on the first photoelectric conversion layer,
The liquid crystal display device according to claim 10, wherein the distance holding unit is formed integrally with the transparent electrode.   The liquid crystal display device according to claim 9, wherein the distance holding unit has light diffusibility.   The lighting device includes: a light source that emits illumination light; and a light guide layer that is provided so as to surround the light source and directs the light emitted from the light source toward the liquid crystal panel. 2. A liquid crystal display device according to item 1.   The liquid crystal display device according to claim 17, wherein the light source includes a light emitting diode.   19. The first photoelectric conversion layer and the second photoelectric conversion layer each include an amorphous silicon layer and a microcrystalline silicon layer stacked on the amorphous silicon layer. 19. Liquid crystal display device. A lighting device unit used in a liquid crystal display device and combined with a liquid crystal panel,
An illumination device that emits illumination light toward the liquid crystal panel;
A light transmissive solar cell that is disposed between the liquid crystal panel and the illumination device and capable of transmitting illumination light emitted from the illumination device toward the liquid crystal panel;
The solar cell includes a first photoelectric conversion layer that performs photoelectric conversion using external light transmitted through a liquid crystal panel, and a second photoelectric conversion layer that performs photoelectric conversion using illumination light emitted from the illumination device. A lighting device unit. A solar cell used in a liquid crystal display device and disposed between a liquid crystal panel and an illumination device for irradiating illumination light toward the liquid crystal panel,
A transparent substrate having a surface and having optical transparency;
A first photoelectric conversion layer and a second photoelectric conversion layer provided on the surface and stacked on each other;
The first photoelectric conversion layer performs photoelectric conversion using external light transmitted through the liquid crystal panel, and the second photoelectric conversion layer performs photoelectric conversion using illumination light emitted from an illumination device. battery.

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