Liquid crystal display device

Abstract

To reduce the size of a camera unit.SOLUTION: A liquid crystal display device includes: a liquid crystal panel including a display region for displaying an image against the visible side; a backlight part including a plurality of optical sheets; a light source for emitting non-visible light and located in the backlight part or behind the backlight part; a diffusion structure part for diffusing non-visible light from the light source and located on the visible side of the light source; and a lens unit for condensing, on a sensor, light diffused by the diffusion structure part and reflected by a subject. The plurality of optical sheets include a diffusion sheet for diffusing visible light. The diffusion structure part is smaller than the display region and selectively located at a position irradiated with non-visible light from the light source. At least one of the plurality of optical sheets exists between the diffusion structure part and the light source.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a liquid crystal display device.

Background Art

[0002] Liquid crystal display devices are applied in a wide range of fields, from small mobile phones to large television monitors, taking advantage of the characteristics of low power consumption and high definition. For fingerprint and gesture recognition, a camera device including a light source and a sensor for recognizing a subject may be mounted on the liquid crystal display device.

[0003] For example, one of the tools for realizing gestures is an NIR-ToF camera unit including a VCSEL (Vertical Cavity Surface Emitting Laser) that emits near-infrared light (NIR light), a ToF (Time Of Flight) image sensor, and a lens unit.

[0004] The distance to the subject is calculated from the time it takes for the NIR light emitted from the VCSEL to hit the subject, reflect, and return to the ToF image sensor through the lens unit. When used in a liquid crystal panel, the NIR-ToF camera unit is often installed on the back side of the cover panel. The area where the NIR-ToF camera unit is arranged becomes a non-display area.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] For example, in a NIR-ToF camera unit, in order to reduce the shielding of the emitted light of the VCSEL by the lens unit, it is important to keep a distance between the lens unit and the VCSEL. In particular, in the case of a type corresponding to a wide angle, it is necessary to increase the distance, making it difficult to reduce the outer dimensions of the NIR-ToF camera unit. Further, when the NIR-ToF camera unit is disposed on the back surface of the liquid crystal panel, it is necessary to provide holes in the liquid crystal panel for both the lens unit and the VCSEL, which are non-display regions where the image is not displayed.

Means for Solving the Problem

[0007] A liquid crystal display device according to an aspect of the present disclosure includes a liquid crystal panel including a display area for displaying an image to a viewing side, a backlight unit provided on the back surface of the liquid crystal panel and including a plurality of optical sheets arranged in a stacked manner, a light source disposed within the backlight unit or on the back surface of the backlight unit and emitting non-visible light, a diffusion structure portion present on the viewing side of the light source and diffusing the non-visible light from the light source, and a lens unit that condenses the light diffused by the diffusion structure portion, irradiated onto a subject, and reflected by the subject onto a sensor. The plurality of optical sheets include a diffusion sheet that diffuses visible light, the diffusion structure portion is smaller than the display area and is selectively disposed at a position irradiated with non-visible light from the light source, and at least one of the plurality of optical sheets is present between the diffusion structure portion and the light source.

Effect of the Invention

[0008] According to an aspect of the present disclosure, the camera unit used in the liquid crystal display device can be miniaturized.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be noted that this embodiment is merely an example for realizing the present disclosure and does not limit the technical scope of the present disclosure.

[0011] The present disclosure relates to a camera unit including a light emitting unit and a light receiving unit. An example of the camera unit is a NIR-ToF camera unit. The light from the light source unit is near-infrared light (NIR light), and the light receiving unit is a ToF (Time Of Flight) camera.

[0012] For example, in a NIR-ToF camera unit, in order to reduce the shielding of the emitted light of the light source unit by the light receiving unit, it is important to keep a distance between the light receiving unit and the light source unit. In particular, in the case of a type corresponding to a wide angle, it is necessary to increase the distance, and it is difficult to reduce the outer size of the NIR-ToF camera unit. Further, when the NIR-ToF camera unit is disposed on the back surface of the liquid crystal panel, it is necessary to provide holes in the liquid crystal panel for both the light receiving unit and the light source unit, and these are non-display areas where no image is displayed.

[0013] In one embodiment of the present disclosure, a diffusion structure portion (also simply referred to as a diffusion structure) of the light source unit is disposed at an upper position away from the light emitting surface of the light source. The distance between the light source unit and the light receiving unit can be reduced, and the size of the camera unit can be made smaller. Hereinafter, the embodiments of the present disclosure will be described more specifically. <Embodiment 1> [Configuration of Liquid Crystal Display Device]

[0014] FIG. 1 schematically shows a liquid crystal display device according to the present embodiment. In the display area 15 of the liquid crystal panel, the liquid crystal display device 1 displays an image toward the viewing side. The periphery of the display area 15 is a frame area 18 which is a non-display area. The liquid crystal display device 1 includes a backlight unit (not shown) disposed on the back surface side of the liquid crystal panel and a camera unit 10.

[0015] FIG. 2 is a plan view schematically showing a configuration example of the camera unit 10. The camera unit 10 includes a light source unit 11, a light receiving unit 13, and a substrate 17. The light source unit 11 and the light receiving unit 13 are disposed on the substrate 17. Instead of the substrate 17, two substrates may be used, and the light source unit 11 and the light receiving unit 13 may be disposed on different substrates.

[0016] The light source unit 11 emits light toward the subject existing on the viewing side. The light receiving unit 13 receives the irradiation light from the light source unit 11 reflected by the subject. The camera unit 10 is, for example, a NIR-ToF camera unit. The light from the light source unit 11 is near-infrared light (NIR light). The wavelength of the near-infrared light is 750 nm or more and less than 1000 nm. The light receiving unit 13 is a ToF camera.

[0017] The control circuit on the substrate 17 measures information corresponding to the time from the emission of light from the light source unit 11 until the reflected light of the near-infrared light irradiated on the subject returns to the light receiving unit 13. Thereby, the distance from the camera unit 10 to the subject and the three-dimensional shape of the subject can be detected. Note that the features of the present disclosure can be applied to a camera unit that uses non-visible light having a wavelength different from that of the NIR-ToF camera unit or a measurement method.

[0018] Returning to FIG. 1, as described above, the camera unit 10 includes the light source unit 11 and the light receiving unit 13. The light receiving unit 13 of the camera unit 10 is disposed in the hole 19 formed in the display area 15, and that area is a non-display area. The light source unit is disposed in the display area 15. The entire circumference of the hole 19 is surrounded by the display area.

[0019] FIG. 3 schematically shows a partial cross-sectional structure of the liquid crystal display device 1 according to an embodiment of the present disclosure. In FIG. 3, the upper side is the viewing side or the subject side. The liquid crystal display device 1 includes a liquid crystal panel 50 and a backlight unit 30 disposed on the back side of the liquid crystal panel 50. The liquid crystal display device 1 further includes the light receiving unit 13 and the light source unit 11. As described with reference to FIG. 2, the light receiving unit 13 and the light source unit 11 are included in the camera unit 10.

[0020] The liquid crystal panel 50 may be any type of liquid crystal panel, such as TN (Twisted Nematic) or IPS (In Plane Switching). For example, the liquid crystal panel 50 includes, for example, a TFT substrate and a counter substrate facing the TFT substrate. A liquid crystal layer is sandwiched between the TFT substrate and the counter substrate. The TFT substrate includes an insulating substrate that is transparent to visible light. The insulating substrate is, for example, rectangular, and one of its main surfaces faces one of the main surfaces of the counter substrate. A polarizing plate is attached to the main surface of the insulating substrate on the side opposite to the liquid crystal layer.

[0021] For example, in an IPS liquid crystal panel, a pixel electrode and a common electrode for applying an electric field to the liquid crystal layer are arranged on the TFT substrate. Each pair of the pixel electrode and the common electrode applies an electric field to the liquid crystal of one pixel. The amount of transmitted light of the pixel changes due to the applied electric field. A thin film transistor (TFT) array for selecting a pixel to be controlled is formed on the TFT substrate.

[0022] For example, in a TN liquid crystal panel, pixel electrodes for applying an electric field to the liquid crystal layer are arranged on the TFT substrate, and a common electrode is arranged on the counter substrate. An electric field is applied to the liquid crystal of one pixel between the pixel electrode and the common electrode. The amount of transmitted light of the pixel changes due to the applied electric field. A TFT array for selecting a pixel to be controlled is formed on the TFT substrate.

[0023] In a color liquid crystal panel, the counter substrate includes a color filter. The counter substrate includes an insulating substrate made of glass or resin. The insulating substrate is, for example, rectangular. A polarizing plate is attached to the main surface of the insulating substrate on the side opposite to the liquid crystal layer.

[0024] One of the TFT substrate or the counter substrate is the front side or the viewing side where the observer is present, and the other is the rear side or the back side. That is, the backlight unit 30 is arranged on the TFT substrate side or the counter substrate side of the liquid crystal panel.

[0025] The backlight unit 30 irradiates the liquid crystal panel 50 with light from its back side. The liquid crystal panel 50 displays an image based on the input drive signal. The observer observes the display image formed by the light transmitted through the liquid crystal panel 50 from the backlight unit 30.

[0026] The backlight unit 30 is housed in the chassis 301 and includes a plurality of optical sheets arranged in a stacked manner. The plurality of optical sheets include, for example, a reflection sheet 302, a light guide plate 303, a diffusion sheet 304, a condenser sheet 305, and a two-dimensional condenser sheet 306 from the lower side of FIG. 3, that is, from the side opposite to the liquid crystal panel 50. Each optical sheet includes a functional part that controls visible light (such as diffusion and light condensation).

[0027] The sizes of the reflection sheet 302, the light guide plate 303, the diffusion sheet 304, the condenser sheet 305, and the two-dimensional condenser sheet 306 may each be equal to or larger than the size of the display area 15 of the liquid crystal panel. When viewed in the stacking direction of the backlight unit 30 and the liquid crystal panel 50, the entire display area 15 may overlap with each optical sheet and be housed within the outer shape of each optical sheet. Note that some optical sheets may be smaller than the display area 15.

[0028] The chassis 301 may be, for example, in the shape of an open-top box. The optical sheets 302 to 306 are stacked and arranged on the bottom surface of the chassis 301. The chassis 301 that houses the optical sheets 302 to 306 can be formed of metal or resin.

[0029] Each optical sheet can be formed of resin, and the thickness of each optical sheet is not limited. For example, the reflection sheet 302 may be a polyolefin-based white reflector that effectively reflects visible light. The light guide plate 303 is an optical sheet for obtaining uniform planar visible light and can be formed of polycarbonate or polystyrene. Generally, the light guide plate 303 is thicker than other optical plates and is in the range of several millimeters, for example, 5 mm to 8 mm. The thickness of the other optical sheets is from several tens of micrometers to several hundreds of micrometers, for example, in the range of 20 μm to 500 μm.

[0030] The diffusion sheet 304 may have a structure in which acrylic beads are adhered to a polyethylene terephthalate substrate, for example. The condensing sheets 305, 305 have prisms arranged on the surface and improve the front luminance of the liquid crystal display device. The condensing sheets 305, 305 can use, for example, polyester or polycarbonate as the material.

[0031] The types and numbers of the optical sheets included in the backlight unit 30 are arbitrary and are not limited to the configuration of the present disclosure. Further, FIG. 3 shows a configuration example of an edge type backlight unit, but a direct - type backlight unit in which light sources are arranged in the plane of the liquid crystal panel 50 may be used. The side of the liquid crystal panel 50 as viewed from the backlight unit 30 is the front side or the light - emitting side.

[0032] As described with reference to FIG. 1, the light - receiving unit 13 is disposed in the holes 19 formed in the liquid crystal panel 50 and the backlight unit 30. The light - receiving unit 13 includes an image sensor 133 disposed on a substrate 17 disposed on the back side of the backlight unit 30.

[0033] The image sensor 133 is, for example, a ToF image sensor. The ToF image sensor measures the distance between the ToF image sensor and each point of the subject by measuring the time from when the light irradiated from the light source unit 11 is reflected by each point of the subject and returns to the image sensor. Note that the type of the image sensor 133 is not particularly limited, and instead of the image sensor, a one - dimensional sensor may be used.

[0034] The light - receiving unit 13 further includes a lens unit 130. The lens unit 130 includes a lens group 131 disposed on the viewing side (front side) of the image sensor 133 and a lens barrel 135 that fixedly supports the lens group 131. The lens group 131 includes a plurality of lenses arranged from the image sensor 133 side to the viewing side. Each lens is fixed to the lens barrel 135.

[0035] In the example shown in FIG. 3, an image sensor 133 disposed directly below the lens group 131 is disposed within a lens barrel 135. The lens group 131 condenses near-infrared light reflected by a subject onto the image sensor 133. As described above, the lens unit 130 is disposed within holes of the liquid crystal panel 50 and the backlight unit 30, and neither the liquid crystal panel 50 nor the backlight unit 30 exists on the viewing side (front side) of the lens unit 130. The lens unit 130 is surrounded by side walls of a chassis 301 of the backlight unit 30. The side walls of the chassis 301 surrounding the lens unit 130 may be omitted.

[0036] The light source unit 11 includes a light source 111 and a diffusion sheet 115. The diffusion sheet 115 is an example of a diffusion structure portion. An example of the light source 111 is a VCSEL (Vertical Cavity Surface Emitting Laser). The VCSEL is a semiconductor laser that emits laser light vertically from the upper surface (the opposite surface of the substrate 17). Note that the structure of the light source 111 is not limited as long as it can emit light toward the viewing side with a predetermined intensity and emission angle.

[0037] The light source 111 is disposed on a substrate 17 disposed on the back side of the backlight unit 30 and at a position away from the light receiving unit 13. The light source 111 is disposed on the back side of the optical sheets 302 to 306 of the backlight unit 30. That is, the light source 111 is disposed on the back side of the lowermost reflection sheet 302.

[0038] In the configuration example shown in FIG. 3, the light source 111 is disposed within a hole provided in the chassis 301. Thereby, the light from the light source 111 can be made to enter the optical sheet without being blocked by the chassis 301.

[0039] There are no other members between the light source 111 and the reflection sheet 302, and the near-infrared light from the light source 111 directly enters the reflection sheet 302. At least a part of the near-infrared light passes through the optical sheets 302 to 306 of the backlight unit 30 and enters the diffusion sheet 115 of the light source unit 11. A part of the near-infrared light may be absorbed, reflected or diffused by the optical sheets included in the backlight unit 30. In the configuration example shown in FIG. 3, between the light source 111 and the diffusion sheet 115, there are portions of all the optical sheets 302 to 306 included in the backlight unit 30, and there are no other members.

[0040] The diffusion sheet 115 of the light source unit 11 is arranged at a position overlapping with the light emitting surface (the upper surface in FIG. 3) of the light source 111 when viewed in the stacking direction of the optical sheets 302 to 306, that is, when viewed in the vertical direction of FIG. 3. The near-infrared light from the light source 111 linearly passes through the optical sheets 302 to 306 and enters the diffusion sheet 115. The size of the diffusion sheet 115 is smaller than the size of the display area 15 and is selectively arranged at a position irradiated with the near-infrared light from the light source 111.

[0041] In the configuration example shown in FIG. 3, the diffusion sheet 115 is arranged between the condenser sheet 306 and the liquid crystal panel 50. The condenser sheet 306 is the topmost optical sheet of the backlight unit 30. For example, the diffusion sheet 115 may be adhered to the surface of the condenser sheet 306 with an adhesive. For example, the refractive index of the adhesive is a value close to the refractive indices of the diffusion sheet 115 and the condenser sheet 306 and may be between them. For example, the diffusion sheet 115 may be in contact with the back surface of the liquid crystal panel 50.

[0042] In the configuration example shown in FIG. 3, a part or all of the diffusion sheet 115 overlaps with a part of the display area 15 of the liquid crystal panel 50. Thereby, the display area 15 can be expanded. By arranging the diffusion sheet 115 on the back side of the liquid crystal panel 50, the influence on the display in the display area 15 can be reduced. Note that all of the diffusion sheet 115 may be outside the display area 15.

[0043] The area of the diffusion sheet 115 is smaller than the areas of the optical sheets 302 to 306 of the backlight unit 30. The diffusion sheet 115 has an area sufficient to receive the light from the light source 111. The diffusion sheet 115 receives, for example, a range including at least the range of the half-value width from the center of the light from the light source 111. By reducing the area of the diffusion sheet 115, the influence on the display of the liquid crystal panel 50 can be reduced.

[0044] The diffusion sheet 115 is formed of a material and structure capable of effectively diffusing near-infrared light. The diffusion sheet 115 can be formed of resin or glass. The diffusion sheet 115 has a diffusion configuration for diffusing near-infrared light, such as the structure of a diffuser plate or a diffraction grating. The diffusion sheet 115 enables more uniform diffusion of near-infrared light. It is desirable that the diffusion sheet 115 has a diffused light quantity profile such that the near-infrared light diffused by the diffusion sheet 115 is uniformly irradiated onto the subject within the angular field of view of the light receiving unit 13.

[0045] FIG. 10 shows an example of the diffused light quantity profile by the diffusion sheet 115. FIG. 10 shows a normal distribution 701 and the diffused light quantity profile 702 of the diffusion sheet 115. The vertical axis indicates the light quantity of the near-infrared light from the sheet 115. The horizontal axis indicates the angle with respect to the optical axis of the incident light. A rectangular diffused light quantity profile 702 with a predetermined light intensity closer to flat is desirable than the normal distribution 701 in which the intensity of the near-infrared light diffused by the diffusion sheet 115 decreases according to the angle from the optical axis.

[0046] The diffusion sheet 115 may diffuse near-infrared light at a wider angle than the optical sheets 302 to 306 including the diffusion sheet 304 of the backlight unit 30. The diffusion sheet 115 is designed to diffuse the light from the light source 111 at a desired angle. The diffusion angle of the visible light by the diffusion sheet 115 may be smaller than the diffusion angle of the near-infrared light. Thereby, the influence on the display of the liquid crystal panel 50 can be reduced. Also, the diffusion angle of the visible light by any diffusion sheet in the backlight unit 30 may be larger than the diffusion angle of the near-infrared light.

[0047] Between the diffusion sheet 115 of the light source unit 11 and the light emitting surface (upper surface) of the light source 111, there is an optical sheet of the backlight unit, and the diffusion sheet 115 is arranged at a distance from the light source 111. Thereby, the diffusion position of the near-infrared light can be brought closer to the viewing side, and the distance between the light source unit 11 and the light receiving unit 13 can be reduced. In the configuration example shown in FIG. 3, the diffusion sheet 115 is arranged at a position farther from the viewing side than the upper surface (the surface closest to the viewing side) of the lens group 131, that is, at a position closer to the substrate 17.

[0048] Hereinafter, the positional relationship between the diffusion sheet 115 of the light source unit 11 and the lens unit 130 will be described. FIG. 4 is a diagram for explaining the positional relationship between the light source unit 11 and the lens unit 130. FIG. 4 shows the light source 111, the diffusion sheet 115, the lens group 131, and the lens barrel 135. An axis connecting the point where the lower surface of the lens unit 130 intersects the central axis of the lens group 131 and the point where the lower surface of the light source 111 intersects the optical axis 113 of the light source 111 is defined as the x-axis. Also, the central axis of the lens group 131 is defined as the y-axis.

[0049] The light source 111 and the diffusion sheet 115 are arranged with respect to the lens unit 130 at positions where the light diffused by the diffusion sheet 115 is not blocked by the lens unit 130. As shown in FIG. 4, the light from the light source 111 diffused by the diffusion sheet 115 has a diffusion angle θ. The lens unit 130 has a camera angle of view φ. Also, the lens unit 130 has a height h and an outer diameter r. In this example, the lens unit 130 is cylindrical, but it may have other shapes. In that case, instead of the outer shape r, the distance (shortest distance) between the central axis of the lens group 131 and the point on the lens unit 130 closest to the diffusion sheet 115 may be defined as r.

[0050] In FIG. 4, the line 331 depending on the camera angle of view φ is represented by the following function. y = x * tan((180 - φ) / 2) + h - r * tan((180 - φ) / 2) In addition, the line 332 that depends on the diffusion angle θ of the diffusion sheet 115 is represented by the following function. y = -x * 1 / tan(θ / 2) + r / tan(θ / 2) + h

[0051] Among the diffusion sheet 115, the point 333(x, y) closest to the lens unit 130 may be arranged in the region represented by the following formula. When the diffusion sheet 115 exists in the region that satisfies the following formula, near-infrared diffused light can be efficiently used without being blocked by the lens unit 130. -x * 1 / tan(θ / 2) + r / tan(θ / 2) + h ≦y≦x * tan(180 - φ) + h - r * tan(180 - φ)

[0052] As described above, by arranging the diffusion sheet of the light source unit outside the angular field of view of the lens unit and arranging the lens unit outside the diffusion range of the near-infrared light determined by the diffusion angle θ of the diffusion sheet, it is possible to effectively suppress the light from the light source unit from being blocked by the lens unit. <Other Embodiments>

[0053] FIG. 5 schematically shows a partial cross-sectional structure of a liquid crystal display device 1 according to another embodiment of the present disclosure. In the following, the differences from the configuration example shown in FIG. 3 will be mainly described. Unless otherwise specified, the description with reference to FIG. 3 may be applicable.

[0054] In the configuration example shown in FIG. 5, the diffusion sheet 115 of the light source unit is arranged between the liquid crystal panel 50 and the cover panel 55. The cover panel 55 is arranged on the viewing side of the liquid crystal panel 50 and is a member formed of glass or resin. The cover panel 55 transmits visible light and near-infrared light. In this way, by arranging the diffusion sheet 115 on the viewing side of the liquid crystal panel 50, it becomes possible to bring the light source unit 11 closer to the light receiving unit 13. The cover panel 55 prevents damage to the diffusion sheet 115 and the liquid crystal panel 50. Note that the cover panel 55 may be omitted.

[0055] FIG. 6 schematically shows a partial cross-sectional structure of a liquid crystal display device 1 according to another embodiment of the present disclosure. The configuration example shown in FIG. 6 further includes a near-infrared transmission filter (IR filter) 56 with respect to the configuration example shown in FIG. 5. The IR filter 56 is disposed on the viewing side of the cover panel 55, transmits near-infrared light, and absorbs visible light. The IR filter 56 covers the entire area of the light receiving unit 13 and the light source unit 11 when viewed from the viewing side. The IR filter 56 can prevent unnatural display caused by the light receiving unit 13, the light source unit 11, and the diffusion sheet 115 from being visually recognized. In the configuration example shown in FIG. 3, an IR filter may be similarly disposed on the viewing side of the liquid crystal panel 50.

[0056] FIG. 7 schematically shows a partial cross-sectional structure of a liquid crystal display device 1 according to another embodiment of the present disclosure. Compared with the configuration example shown in FIG. 5, the diffusion sheet 115 is disposed on the viewing side of the cover panel 55. Other configurations are the same as those shown in FIG. 5. The diffusion sheet 115 is disposed on the outermost surface of the liquid crystal display device 1. By increasing the distance between the diffusion sheet 115 and the light source 111, the distance between the light receiving unit 13 and the light source unit 11 can be further reduced. The diffusion sheet 115 disposed on the viewing side of the cover panel 55 can reduce the reflection of the cover panel 55 of near-infrared light on the back surface.

[0057] FIG. 8 schematically shows a partial cross-sectional structure of a liquid crystal display device 1 according to another embodiment of the present disclosure. In the following, the differences from the configuration example shown in FIG. 3 will be mainly described. Unless otherwise specified, the description with reference to FIG. 3 may be applicable. Compared with the configuration example shown in FIG. 3, the diffusion sheet 115 is disposed inside the optical sheets 302 to 306 of the backlight unit 30.

[0058] For example, the diffusion sheet 115 may be disposed in a hole formed in one or more optical sheets of the backlight unit 30. The diffusion sheet 115 may be sandwiched between adjacent optical sheets of the backlight unit 30 and may overlap a part of all the optical sheets 302 to 306 of the backlight unit 30 when viewed in the stacking direction.

[0059] In the configuration example shown in FIG. 8, the diffusion sheet 115 is disposed within the holes formed in the condenser sheet 305 and is sandwiched between the condenser sheet 306 and the diffusion sheet 304. The diffusion sheet 115 may be sandwiched between other optical sheets, for example, between the light guide plate 303 and the diffusion sheet 304 or between the light guide plate 303 and the condenser sheet 305. Thereby, while increasing the distance between the light source 111 and the diffusion sheet 115, the influence on the display by the liquid crystal panel 50 can be reduced.

[0060] FIG. 9 schematically shows a partial cross-sectional structure of the liquid crystal display device 1 according to another embodiment of the present disclosure. Hereinafter, the differences from the configuration example shown in FIG. 3 will be mainly described. In the configuration example shown in FIG. 9, the substrate 17 shown in FIG. 3 is divided into two substrates 171 and 172. The two substrates 171 and 172 are separated. The light receiving unit 13 is disposed on the substrate 171, and the light source 111 is disposed on the substrate 172. Thereby, the degree of freedom in arranging the light source unit 11 and the light receiving unit 13 can be increased, and the assembly becomes easy. The divided substrate configuration can also be applied to the configuration examples shown in FIGS. 5 to 8.

[0061] The light source and the diffusion structure part included in the light source unit 11 can each have various configurations. For example, the diffusion structure part for near-infrared light may be formed not only on the diffusion sheet 115 that can be disposed at various positions or have various shapes as described above, but also on a common member with other functional parts. For example, the diffusion structure part can even be formed on the insulating substrate or the cover panel 55 of the liquid crystal panel 50. In another example, the diffusion structure part may be formed in a region other than other functional parts included in the optical sheet included in the backlight unit 30, for example, a region excluding the condensing and diffusing parts for visible light.

[0062] In the illustrated configuration example above, the liquid crystal panel 50 has a hole on the front side of the light receiving unit 13, and the light receiving unit 13 is exposed from the liquid crystal panel 50. In other configuration examples, the liquid crystal panel 50 may not have a hole for the light receiving unit 13 and may block the front side thereof. That is, in the stacking direction, the liquid crystal panel 50 may overlap the entire light receiving unit 13. For example, in the structural example shown in FIG. 5 or 6, the hole for the light receiving unit 13 formed in the liquid crystal panel 50 is blocked, and the light receiving unit 13 is covered in the same manner as the cover panel 55.

[0063] As described above, the embodiments of the present disclosure have been described, but the present disclosure is not limited to the above embodiments. A person skilled in the art can easily change, add, and convert each element of the above embodiments within the scope of the present disclosure. It is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment.

Explanation of Reference Numerals

[0064] 1 Liquid crystal display device 10 Camera unit 11 Light source unit 13 Light receiving unit 15 Display area 17 Substrate 30 Backlight unit 50 Liquid crystal panel 55 Cover panel 111 Light source 115 Diffusion sheet 130 Lens unit 131 Lens group 133 Image sensor 135 Lens barrel 301 Chassis 302~306 Optical sheet

Claims

1. A liquid crystal panel including a display area for displaying an image to a viewing side, a backlight unit provided on the back surface of the liquid crystal panel and including a plurality of optically sheets arranged in a stacked manner, a light source disposed within the backlight unit or on the back surface of the backlight unit, which emits non-visible light, a diffusion structure portion present on the viewing side of the light source and diffusing the non-visible light from the light source, a lens unit that collects the light diffused by the diffusion structure portion, irradiated onto a subject, and reflected by the subject onto a sensor, comprising: the plurality of optically sheets includes a diffusion sheet for diffusing visible light, the diffusion structure portion is smaller than the display area and is selectively disposed at a position irradiated with the non-visible light from the light source, at least one of the plurality of optically sheets is present between the diffusion structure portion and the light source, a liquid crystal display device.

2. The liquid crystal display device according to claim 1, wherein the diffusion structure portion is disposed outside the angular field of view of the lens unit, and the lens unit is disposed outside the diffusion range of the non-visible light of the diffusion structure portion. A liquid crystal display device.

3. The liquid crystal display device according to claim 1, wherein a part or all of the diffusion structure portion overlaps with a part of the display area of the liquid crystal panel. A liquid crystal display device.

4. The liquid crystal display device according to claim 1, wherein the diffusion structure portion is disposed between the liquid crystal panel and the backlight unit. A liquid crystal display device.

5. The liquid crystal display device according to claim 1, wherein all the optically sheets of the backlight unit are disposed between the light source and the liquid crystal panel. A liquid crystal display device.

6. The liquid crystal display device according to claim 1, further comprising a cover panel disposed on the viewing side of the liquid crystal panel, wherein the diffusion structure portion is disposed between the liquid crystal panel and the cover panel. A liquid crystal display device.

7. The liquid crystal display device according to claim 1, further comprising a cover panel disposed on the viewing side of the liquid crystal panel, wherein the diffusion structure portion is disposed on the viewing-side surface of the cover panel. A liquid crystal display device.

8. The liquid crystal display device according to claim 1, wherein the lens unit is disposed in a hole provided in the backlight unit. A liquid crystal display device.

9. The liquid crystal display device according to claim 1, The lens unit is disposed in a hole provided in the liquid crystal panel and the backlight unit. Liquid crystal display device.

Images