JP2013050469A - Liquid crystal display device, illumination device unit and solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of achieving power saving while maintaining display quality and an illumination device unit and a solar cell used in the liquid crystal display device.SOLUTION: A liquid crystal display device 10 comprises: a liquid crystal panel 21 having a display surface 22; a backlight 61 which is disposed on a side opposite to a side on which the display surface 22 is formed to the liquid crystal panel 21 and irradiates the liquid crystal panel 21 with illumination light; and a solar cell 31 arranged between the liquid crystal panel 21 and the backlight 61. The solar cell 31 has a photoelectric conversion layer 32 for performing photoelectric conversion using external light passed through the liquid crystal panel 21. On the photoelectric conversion layer 32, an aperture 40 is formed in which an air layer 41 for penetrating in a direction connecting the backlight 61 and the liquid crystal panel 21 and passing the illumination light irradiated from the backlight 61 toward the liquid crystal panel 21 is disposed.

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. LED light emitted from the LED illumination device is reflected by the reflector and then emitted from the back surface side of the solar cell to the front surface 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.

  On the other hand, also in a liquid crystal display device provided with a liquid crystal panel, reduction of power consumption is calculated | required as a liquid crystal panel enlarges. On the other hand, the electro-optical device disclosed in Patent Document 2 is used in liquid crystal panels such as mobile phones, personal computers, and digital still cameras, and drives liquid crystal panel devices using power generated by solar cells. To do.

  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. In addition, the electro-optical device disclosed in Patent Document 2 has a problem that display quality deteriorates due to a decrease in aperture ratio because a photoelectric conversion element of a solar cell is formed in a display region of a liquid crystal panel.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-described problems, and provide a liquid crystal display device capable of saving power while maintaining display quality, and a lighting device unit and a solar cell used in the liquid crystal display device. It is to be.

  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 solar cell disposed between the liquid crystal panel and the lighting device. The solar cell has a photoelectric conversion layer that performs photoelectric conversion using external light transmitted through the liquid crystal panel. The photoelectric conversion layer is formed with an opening through which a light transmission layer for penetrating the illumination light irradiated from the illumination device toward the liquid crystal panel is disposed so as to penetrate the illumination device and the liquid crystal panel. .

  According to the liquid crystal display device configured as described above, the illumination light irradiated from the illumination device reaches the liquid crystal panel through the light transmission layer by forming an opening in which the light transmission layer is disposed in the photoelectric conversion layer. . Thereby, the structure which attaches a solar cell with respect to a liquid crystal panel becomes possible, and the display quality of a liquid crystal panel can be maintained. In addition, power consumption of the liquid crystal display device can be reduced by using the power generated by the solar battery as the driving power of the liquid crystal display device.

  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 distance holding unit has a column shape extending from directly above the 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 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 has a transparent electrode laminated on the 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 light emitted from the light source has a directivity in which the light component in the direction orthogonal to the direction connecting the lighting device and the liquid crystal panel is larger than the light component in the direction connecting the lighting device and the liquid crystal panel. Have. According to the liquid crystal display device configured as described above, the luminance uniformity of the liquid crystal panel can be improved by suppressing the light emitted from the light source from being linearly directed to the liquid crystal panel.

  Preferably, the light source is disposed immediately below the photoelectric conversion layer. According to the liquid crystal display device configured as described above, the luminance uniformity of the liquid crystal panel can be improved by suppressing the light emitted from the light emitting diode from being linearly directed to the liquid crystal panel through the light transmission layer. it can.

  Preferably, the liquid crystal display device further includes a reflective layer provided to face the light source and capable of reflecting illumination light emitted from the light source. According to the liquid crystal display device configured as described above, the luminance uniformity of the liquid crystal panel can be improved by more actively reflecting the light emitted from the light source.

  Preferably, the solar cell extends in a strip shape across the plurality of photoelectric conversion layers arranged with openings and the plurality of photoelectric conversion layers, and transfers heat generated in the photoelectric conversion layer. A heat transfer member. According to the liquid crystal display device configured as described above, the heat generated in each photoelectric conversion layer can be efficiently radiated through the heat transfer member. Thereby, it can suppress that the heat which generate | occur | produced with the solar cell is transmitted to a liquid crystal panel.

  Preferably, the heat transfer member functions as a reflective layer capable of reflecting the illumination light irradiated from the illumination device. According to the liquid crystal display device configured as described above, it is possible to obtain an effect of efficiently dissipating heat generated in the photoelectric conversion layer and an effect of improving the luminance uniformity of the liquid crystal panel with a simple configuration. .

  Preferably, the light transmission layer has a light diffusibility for diffusing light from the illumination device toward the liquid crystal panel. 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.

  Preferably, the photoelectric conversion layer includes an amorphous silicon layer and a microcrystalline silicon layer stacked on the amorphous silicon layer. According to the liquid crystal display device configured as described above, the photoelectric conversion layer is formed in a tandem structure including an amorphous silicon layer and a microcrystalline silicon layer.

  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. The aperture ratio of the photoelectric conversion layer is larger in the central portion than in the peripheral portion. The effective power generation area of the solar cell means an area where power can be generated by the photoelectric conversion 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.

  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 illumination device unit includes an illumination device that irradiates illumination light toward the liquid crystal panel, and a photoelectric conversion layer that performs photoelectric conversion using external light transmitted through the liquid crystal panel, and is provided between the liquid crystal panel and the illumination device. A solar cell to be disposed. The photoelectric conversion layer is formed with an opening in which a light transmission layer for penetrating the illumination light irradiated from the illumination device toward the liquid crystal panel is disposed in a direction connecting the illumination device and the solar cell. .

  According to the illuminating device unit configured as described above, by using the illuminating device unit and the liquid crystal panel in combination, a structure in which a solar cell is externally attached to the liquid crystal panel becomes possible, and the display quality of the liquid crystal panel is maintained. can do. In addition, power consumption of the liquid crystal display device can be reduced by using the power generated by the solar battery as the driving power of the liquid crystal display device.

  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. A solar cell includes a transparent substrate having a surface and light transmittance, and a photoelectric conversion layer that is provided on the surface and performs photoelectric conversion using external light transmitted through a liquid crystal panel. The photoelectric conversion layer is formed with an opening through which a light transmission layer for penetrating the illumination light irradiated from the illumination device toward the liquid crystal panel is disposed so as to penetrate the illumination device and the liquid crystal panel. .

  According to the solar cell configured as described above, the solar cell is disposed between the liquid crystal panel and the lighting device, and thus a structure in which the solar cell is externally attached to the liquid crystal panel is possible. Display quality can be maintained. In addition, power consumption of the liquid crystal display device can be reduced by using the power generated by the solar battery as the driving power of the liquid crystal display device.

  As described above, according to the present invention, it is possible to provide a liquid crystal display device capable of saving power while maintaining display quality, and a lighting device unit and a solar cell 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 a top view which shows the liquid crystal display device along the II-II line | wire in FIG. It is sectional drawing which shows the liquid crystal display device along the III-III line | wire in FIG. It is sectional drawing which shows the 1st modification of the liquid crystal display device in FIG. It is sectional drawing which shows the 2nd modification of the liquid crystal display device 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 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 7th modification of the liquid crystal display device in FIG. It is a top view which shows the liquid crystal display device along the XIII-XIII line | wire in FIG. It is sectional drawing which shows the modification of the heat exchanger plate shown in FIG. It is sectional drawing which shows the 8th modification of the liquid crystal display device in FIG. It is a top view which shows the 9th modification of the liquid crystal display device in FIG. It is a top view which expands and shows the range enclosed with the dashed-two dotted line XVII in FIG. It is a top view which expands and shows the range enclosed with the dashed-two dotted line XVIII 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 solar cell 31 disposed between the two.

  The solar cell 31 includes a photoelectric conversion layer 32 that performs photoelectric conversion using external light transmitted through the liquid crystal panel 21. The photoelectric conversion layer 32 penetrates in a direction connecting the backlight 61 and the liquid crystal panel 21, and 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 formed.

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, a photoelectric conversion layer 32, and electrodes 33 and 34.

  FIG. 2 is a plan view showing the liquid crystal display device along the line II-II in FIG. FIG. 1 shows a cross section of the liquid crystal display device along the line II in FIG. FIG. 3 is a cross-sectional view showing the liquid crystal display device taken along line III-III in FIG.

  With reference to FIGS. 1 to 3, the photoelectric conversion layer 32 has a function of generating power using the photoelectric effect.

  In the present embodiment, the photoelectric conversion layer 32 is 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 layer 32 which is a thin film solar cell is produced by decomposing gaseous silicon by plasma discharge in a plasma CVD apparatus and laminating a thin silicon film on a glass substrate. When a thin film solar cell is used for the photoelectric conversion layer 32, the technology of the silicon thin film necessary for manufacturing the liquid crystal panel 21 can be horizontally deployed in the manufacture of the solar cell 31, so that the liquid crystal display device 10 having the solar cell 31 can be efficiently used. Can be produced.

  An opening 40 is formed in the photoelectric conversion layer 32. The opening 40 is formed so as to penetrate the photoelectric conversion layer 32 in the direction connecting the liquid crystal panel 21 and the backlight 61. The photoelectric conversion layer 32 is divided into a plurality of cells 32m by the opening 40 (see FIGS. 2 and 3). As shown in FIG. 2, in the plan view of the liquid crystal display device 10 when the display surface 22 is viewed from the front, the plurality of cells 32m are in the direction along the X axis and the direction along the Y axis perpendicular to the X axis. Are spaced apart from each other.

  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 electrode 33 is laminated from the display side of the liquid crystal display device 10 on each cell 32 m of the photoelectric conversion layer 32. The electrode 34 is laminated on the photoelectric conversion layer 32 from the back side of the liquid crystal display device 10. In other words, the electrode 33 is disposed between the photoelectric conversion layer 32 and the liquid crystal panel 21, and the electrode 34 is disposed between the photoelectric conversion layer 32 and the backlight 61.

The electrode 33 is provided as a transparent electrode having optical transparency, and is made of, for example, SnO ₂ (tin oxide). The electrode 34 has a light shielding property, and is formed, for example, by laminating a ZnO (zinc oxide) layer and an Ag (silver) layer. As shown in FIG. 3, the electrode 33 has a connecting portion 33p. The connecting portion 33p is provided so as to connect the electrode 33 and the electrode 34 between the cells 32m adjacent in the Y-axis direction in FIG. With such a configuration, the cells 32m of the photoelectric conversion layers 32 arranged in the Y-axis direction are electrically connected in series.

  The form in which the opening 40 is formed will be described in more detail. As shown in FIGS. 1 and 2, in the cross section along the X-axis direction, the opening 40 includes the electrode 34, the photoelectric conversion layer 32, and the electrode. 33 is formed so as to penetrate 33. As shown in FIG. 2 and FIG. 3, in the cross section along the Y-axis direction, the opening 40 is formed in a form that penetrates the electrode 34 and the photoelectric conversion layer 32 and reaches the electrode 33 that is a transparent electrode. Yes.

  In the present embodiment, the LED 62 is provided so as to be located immediately below the opening 40. More specifically, the LED 62 is provided so as to be located immediately below the opening 40 between the cells 32m of the photoelectric conversion layer 32 adjacent in the X-axis direction.

  Note that the arrangement of the LEDs 62 is not limited to the above-described form. For example, the LEDs 62 may be provided for every other opening 40, or provided so as to be located immediately below the cell 32m of the photoelectric conversion layer 32. Also 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 parallel to the X-axis-Y-axis plane in FIG. The electrode 33, the photoelectric conversion layer 32, and the electrode 34 are laminated | stacked on the surface 37 of the glass substrate 36 in the order mentioned. 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 columnar shape extending from directly above the cell 32 m 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 32 m 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.

  Referring to FIG. 1, a liquid crystal display device 10 is configured by combining a liquid crystal panel 21 and a backlight unit 12 as a lighting device unit. The backlight unit 12 includes a backlight 61 as an illuminating device that irradiates illumination light toward the liquid crystal panel 21, and a photoelectric conversion layer 32 that performs photoelectric conversion using external light transmitted through the liquid crystal panel 21, A solar cell 31 is provided between the liquid crystal panel 21 and the backlight 61. The photoelectric conversion layer 32 penetrates in the direction connecting the backlight 61 and the solar cell 31, and an air layer 41 as a light transmission layer for transmitting the illumination light irradiated from the backlight 61 toward the liquid crystal panel 21. Is formed.

  The solar cell 31 used in the liquid crystal display device 10 and disposed between the liquid crystal panel 21 and a backlight 61 as an illumination device for irradiating illumination light toward the liquid crystal panel 21 has a surface 37. And a glass substrate 36 as a transparent substrate having light transmittance, and a photoelectric conversion layer 32 that is provided on the surface 37 and performs photoelectric conversion using external light transmitted through the liquid crystal panel 21. The photoelectric conversion layer 32 penetrates in a direction connecting the backlight 61 and the liquid crystal panel 21, and 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 formed.

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

  With reference to FIG. 1 and FIG. 3, the light emitted from the LED 62 first passes through the air layer 63 and is irradiated toward the liquid crystal panel 21 as illumination light. At this time, the electrode 34 having a light shielding property and the backlight reflecting plate 65 function as a reflecting layer, so that the LED 62 repeats reflection in the air layer 63 in addition to the light linearly traveling from the LED 62 toward the liquid crystal panel 21. Light traveling toward the liquid crystal panel 21 is generated. Thereby, the brightness nonuniformity of the illumination light irradiated toward the liquid crystal panel 21 from the backlight 61 can be suppressed small.

  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. In particular, in the cross section along the Y-axis direction shown in FIG. 3, the illumination light passes through the air layer 41 and then sequentially passes through the electrode 33 that is a transparent electrode and the glass substrate 36.

  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.

  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. As a result, power generation using external light is performed in the photoelectric conversion layer 32.

  According to the liquid crystal display device 10 according to Embodiment 1 of the present invention configured as described above, the solar cell 31 is liquid crystal in order to cause the illumination light irradiated from the backlight 61 to reach the liquid crystal panel 21 through the air layer 41. A structure externally attached to the panel 21 is possible. 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.

  Further, the electric power generated by the photoelectric conversion layer 32 can be used for light emission of the LED 62 in the backlight 61 and driving of the device in the liquid crystal panel 21. 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. 4 is a cross-sectional view showing a first modification of the liquid crystal display device in FIG. Referring to FIG. 4, the liquid crystal display device according to this modification includes a distance holding unit 71 instead of the 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. 5 is a cross-sectional view showing a second modification of the liquid crystal display device in FIG. With reference to FIG. 5, in this modification, a glass substrate 36 is disposed between the photoelectric conversion layer 32 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 34, the photoelectric converting 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. 6 is a cross-sectional view showing a third modification of the liquid crystal display device in FIG. With reference to FIG. 6, in the present modification, a glass substrate 36 is provided so that the surface 37 faces the liquid crystal panel 21, as in the modification shown in FIG. 5.

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 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. 7 is a cross-sectional view showing a fourth modification of the liquid crystal display device in FIG. Referring to FIG. 7, 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. 8 is a cross-sectional view showing a fifth modification of the liquid crystal display device in FIG. Referring to FIG. 8, in this modification, an LED 83 having a wide directivity is provided on substrate 64 instead of LED 62 in FIG. 1.

  The LED 83 has no main component (peak component of emitted light) in the light emitting direction of the LED 83 in the direction connecting the backlight 61 and the liquid crystal panel 21 (the direction indicated by the arrow 101), and the direction connecting the backlight 61 and the liquid crystal panel 21. There is a main component of the light emitting direction of the LED 83 in a direction orthogonal to (a direction shown by an arrow 102). The light emitting direction of the LED 83 has directivity, and the directivity is higher in the direction orthogonal to the direction in which the backlight 61 and the liquid crystal panel 21 are connected than in the component in the direction in which the backlight 61 and the liquid crystal panel 21 are connected. The ingredient is larger.

  In the present modification, the LED 83 is provided so as to be located immediately below the photoelectric conversion layer 32. In FIG. 8, the emission direction of the light emitted from the LED 83 is indicated by an arrow. As indicated by the arrows, the light from each LED 83 is emitted along the surface of the substrate 64. Furthermore, in this modification, the plurality of LEDs 83 are provided such that the light emission directions from the LEDs 83 adjacent to each other are directed in opposite directions. That is, there are at least two emission directions of each light emitted from the plurality of LEDs 83.

  According to such a structure, it can suppress that the brightness | luminance of the light of the area | region directly above LED83 becomes high compared with the brightness | luminance of the light of another area | region. Furthermore, since the light emission directions from the two adjacent LEDs 83 are opposite to each other, the light can be spread to every corner of the air layer 63. For this reason, the luminance unevenness of the illumination light irradiated from the backlight 61 toward the liquid crystal panel 21 can be further reduced.

  In the present modification, it is most preferable that the main emission direction of the light from the LED 83 is completely parallel to the surface of the substrate 64, but it is not necessarily limited to such a configuration. That is, the LED 83 has directivity, and the directivity of the light component in the direction parallel to the surface of the substrate 64 is larger than the light component in the direction orthogonal to the surface of the substrate 64. Anything is acceptable.

  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. 9 is a sectional view showing a sixth modification of the liquid crystal display device in FIG. In the drawing, the range surrounded by the two-dot chain line IX in FIG. 1 is shown enlarged. Referring to FIG. 9, 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. 10 is a cross-sectional view showing a first modification of the distance holding unit shown in FIG. Referring to FIG. 10, 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. 9 can be acquired.

  FIG. 11 is a cross-sectional view showing a second modification of the distance holding unit shown in FIG. Referring to FIG. 11, in this 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. 9 can be acquired.

  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. 12 is a cross-sectional view showing a seventh modification of the liquid crystal display device in FIG. FIG. 13 is a plan view showing the liquid crystal display device taken along line XIII-XIII in FIG. In FIG. 13, the electrode 34 is omitted.

  With reference to FIG. 12 and FIG. 13, in this modification, the LED 62 is provided so as to be located immediately below the photoelectric conversion layer 32. Further, the backlight 61 is provided with a light guide plate 88 in place of the air layer 63 in FIG. The light guide plate 88 is as already described in the first embodiment, and functions as a light guide layer that directs the light emitted from the LEDs 62 to the liquid crystal panel 21.

  The liquid crystal display device according to this modification further includes a heat transfer plate 86 and a heat dissipation plate 91. The heat transfer plate 86 is disposed to face the LED 62. In the present embodiment, the heat transfer plate 86 is bonded to the surface of the electrode 34 facing the backlight 61. The heat transfer plate 86 and the electrode 34 are electrically insulated from each other by an insulating layer (not shown) interposed therebetween. As shown in FIG. 13, the heat transfer plate 86 is formed to extend in a band shape between the plurality of cells 32 m of the photoelectric conversion layer 32 aligned in the Y-axis direction. The heat transfer plate 86 is made of a member that has high thermal conductivity and can reflect light, for example, aluminum.

  In the plan view of the liquid crystal display device, the heat radiating plate 91 is disposed in the peripheral region of the region where the photoelectric conversion layer 32 is provided. An end portion of the heat transfer plate 86 extending between the plurality of cells 32 m of the photoelectric conversion layer 32 is connected to the heat radiating plate 91. The heat radiating plate 91 is provided as a heat sink that releases heat to the outside, and a large number of fins are formed.

  According to such a configuration, heat generated in each cell 32 m of the photoelectric conversion layer 32 along with power generation is transmitted to the heat radiating plate 91 through the heat transfer plate 86 and can be efficiently radiated from the heat radiating plate 91. Thereby, it can suppress that heat is transmitted from the solar cell 31 to the liquid crystal panel 21. In addition, since the solar cell 31 is efficiently cooled, the power generation efficiency by the photoelectric conversion layer 32 can be improved. In addition, since the heat transfer plate 86 also functions as a reflective layer, the light emitted from the LEDs 62 can be diffused more in the light guide plate 88. Thereby, the brightness nonuniformity of the illumination light irradiated toward the liquid crystal panel 21 from the backlight 61 can be suppressed small.

  In order to promote heat dissipation through the heat radiating plate 91, an air cooling structure using an electric fan or an oil cooling structure for circulating cooling water may be provided.

  Further, a heat pipe may be provided instead of the heat transfer plate 86. The heat pipe is formed, for example, by evacuating the inside of a metal pipe made of aluminum and enclosing a working liquid. The working liquid evaporates on the solar cell 31 side to generate vapor, and the vapor is condensed on the radiator plate 91 side to become liquid. Due to such latent heat transfer accompanying evaporation and condensation, a large amount of heat is transported from the solar cell 31 side to the heat radiating plate 91 side.

  FIG. 14 is a cross-sectional view showing a modification of the heat transfer plate shown in FIG. Referring to FIG. 14, in this modification, the heat transfer plate 86 is provided in a form of being embedded in the light guide plate 88.

  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. 15 is a cross-sectional view showing an eighth modification of the liquid crystal display device in FIG. Referring to FIG. 15, in this modification, a transparent resin layer 42 is disposed in opening 40 instead of air layer 41 in FIG. 1. The transparent resin that forms the transparent resin layer 42 is as described in the first embodiment. The transparent resin layer 42 has a light diffusibility that diffuses 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 42. The powder forming the scattering particles 83 is as described in the third embodiment.

  According to such a configuration, since the light transmitted through the transparent resin layer 42 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 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. 16 is a plan view showing a ninth modification of the liquid crystal display device in FIG. In the figure, a plan view of the photoelectric emission layer 32 constituting the solar cell 31 in FIG. 1 is shown. FIG. 17 is an enlarged plan view showing a range surrounded by a two-dot chain line XVII in FIG. FIG. 18 is an enlarged plan view showing a range surrounded by a two-dot chain line XVIII in FIG.

  With reference to FIGS. 16 to 18, an effective power generation region 110, which is a region where the photoelectric light emitting layer 32 is disposed and in which power can be generated by the photoelectric light emitting layer 32, is illustrated. 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. 16, the central portion 113 having a substantially rectangular planar shape is shown. However, 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 layer 32 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 layer 32 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 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 with high power consumption.

  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 Photoelectric conversion layer, 32m cell, 33,34 electrode, 33p Connection part, 36,64 Glass substrate, 37 surface, 40 opening portion, 41 air layer, 42 transparent resin layer, 51, 71, 78 distance holding portion, 51 m, 51 n resin layer, 52, 63 air layer, 56 bubble, 57 surface, 58 recess, 59 Thermal insulation layer, 61 backlight, 64 substrate, 65 backlight reflector, 76 glass plate, 81, 83 scattered particles, 86 heat transfer plate, 88 light guide plate, 91 heat sink.

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 photoelectric conversion layer that performs photoelectric conversion using external light transmitted through the liquid crystal panel, and a solar cell disposed between the liquid crystal panel and the illumination device;
The photoelectric conversion layer has an opening in which a light transmission layer is provided that penetrates in a direction connecting the illumination device and the liquid crystal panel and transmits illumination light emitted from the illumination device toward the liquid crystal panel. A liquid crystal display device in which a portion is formed.   The liquid crystal display device according to claim 1, further comprising 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. The distance holding unit has a column shape extending from directly above the photoelectric conversion layer toward the liquid crystal panel,
The liquid crystal display device according to claim 2, wherein an air layer is formed immediately above the opening.   The liquid crystal display device according to claim 3, wherein the distance holding unit is formed so as to enclose bubbles.   The distance holding portion is formed by including 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.   6. The liquid crystal display device according to claim 3, wherein the distance holding portion has an uneven surface that forms a boundary with the air layer. 7. The solar cell further includes a transparent substrate disposed between the photoelectric conversion layer and the liquid crystal panel and having light transmittance,
The liquid crystal display device according to claim 3, wherein the distance holding unit is formed integrally with the transparent substrate. The solar cell further has a transparent electrode laminated on the photoelectric conversion layer,
The liquid crystal display device according to claim 3, wherein the distance holding unit is formed integrally with the transparent electrode.   The liquid crystal display device according to claim 2, wherein the distance holding unit has light diffusibility.   10. The lighting device according to claim 1, further comprising: 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 10, wherein the light source includes a light emitting diode.   The light emitted from the light source has a directivity in which the light component in the direction orthogonal to the direction connecting the lighting device and the liquid crystal panel is larger than the light component in the direction connecting the lighting device and the liquid crystal panel. The liquid crystal display device according to claim 10, comprising:   The liquid crystal display device according to claim 10, wherein the light source is disposed immediately below the photoelectric conversion layer.   14. The liquid crystal display device according to claim 10, further comprising a reflective layer provided opposite to the light source and capable of reflecting illumination light emitted from the light source.   The solar cell extends in a strip shape across the plurality of photoelectric conversion layers arranged with the openings provided therebetween and the plurality of photoelectric conversion layers, and transfers heat generated in the photoelectric conversion layers. The liquid crystal display device according to claim 1, further comprising a heat transfer member.   The liquid crystal display device according to claim 15, wherein the heat transfer member functions as a reflective layer capable of reflecting illumination light emitted from the illumination device.   17. The liquid crystal display device according to claim 1, wherein the light transmission layer has a light diffusibility for diffusing light from the illumination device toward the liquid crystal panel.   The liquid crystal display device according to claim 1, wherein the photoelectric conversion layer includes an amorphous silicon layer and a microcrystalline silicon layer stacked on the amorphous silicon layer. 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,
19. The liquid crystal display device according to claim 1, wherein an opening ratio of the photoelectric conversion layer is larger in the central portion than in the peripheral portion. 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 photoelectric conversion layer that performs photoelectric conversion using external light transmitted through the liquid crystal panel, and includes a solar cell disposed between the liquid crystal panel and the illumination device;
The photoelectric conversion layer has an opening in which a light transmission layer is provided that penetrates in a direction connecting the illumination device and the solar cell and transmits illumination light emitted from the illumination device toward the liquid crystal panel. A lighting device unit is formed. 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 photoelectric conversion layer that is provided on the surface and performs photoelectric conversion using external light transmitted through the liquid crystal panel;
The photoelectric conversion layer is formed with an opening that penetrates in a direction connecting the lighting device and the liquid crystal panel and in which a light transmission layer for transmitting the illumination light irradiated from the lighting device toward the liquid crystal panel is disposed. The solar cell.

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