Display device including liquid crystal panel and optical module

Abstract

To detect external light without being accompanied by deterioration in image quality.SOLUTION: The present specification relates to a display device including a liquid crystal panel and an optical module. A first light guide plate of a backlight unit may be positioned between the optical module and the liquid crystal panel. The liquid crystal panel may include a sensing area for detecting external light. The optical module may include: a second light guide plate overlapping with the sensing area of the liquid crystal panel; and an optical element positioned on a route of the external light passed through the first light guide plate and the second light guide plate. The optical module may include a light source element positioned on at least one of lateral faces vertical to a top surface of the second light guide plate toward the first light guide plate.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This specification relates to a display device in which an optical module is located on one side of a liquid crystal panel.

Background Art

[0002] Generally, a display device provides an image to a user. For example, the display device may include a backlight unit and a liquid crystal panel that generates an image using light provided by the backlight unit. The backlight unit may include a backlight light source element located on one side surface of a backlight light guide plate. The liquid crystal panel may be located on the backlight light guide plate.

[0003] The display device may include a light source module for sensing external light. For example, the light source module may include at least one of a camera and an IR sensor. The light source module may overlap a partial region of the liquid crystal panel. For example, the liquid crystal panel may include an active region that overlaps the backlight light guide plate and a sensing region that overlaps the light source module.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem to be solved by this specification is to provide a display device that can prevent the quality of an image provided to a user from being degraded by a sensing region disposed within an active region.

[0005] Another problem to be solved by this specification is to provide a display device that can reduce or minimize the luminance deviation between the active region and the sensing region of the liquid crystal panel.

[0006] Yet another problem to be solved by this specification is to provide a display device that can allow an optical module to sense external light through a sensing region of a liquid crystal panel without degrading the quality of an image.

[0007] The problems to be solved by the present invention are not limited to the problems described above. Problems not mentioned here will be clearly understandable to those skilled in the art from the following description.

Means for Solving the Problems

[0008] The display device according to the technical idea of this specification for achieving the problems to be solved includes a backlight unit. The backlight unit includes a first light guide plate and a first light source element. A liquid crystal panel is located on the upper surface of the first light guide plate. The liquid crystal panel includes a sensing region. A light source module is located on the lower surface of the first light guide plate. The light source module includes a second light guide plate, a second light source element, and an optical element. The upper surface of the second light guide plate overlaps with the sensing region of the liquid crystal panel. The first light guide plate includes a region located between the upper surface of the second light guide plate and the liquid crystal panel. The second light source element and the optical element are located on different surfaces of the second light guide plate.

[0009] The second light source element and the optical element may be located outside the sensing region.

[0010] The second light source element may be located on two opposite side surfaces among the side surfaces perpendicular to the upper surface of the second light guide plate.

[0011] The first light guide plate and the first light source element can be accommodated by a cover bottom. The cover bottom may include a cover hole that overlaps with the sensing region of the liquid crystal panel.

[0012] The optical element may be located on a first side surface perpendicular to the upper surface of the second light guide plate. The second light guide plate may include an inclined surface facing the first side surface.

[0013] A module reflector may be located on the inclined surface of the second light guide plate.

[0014] A module sheet can be located between the optical element and the second light guide plate. The module sheet may include a module adhesive layer, a module filter layer, and a module heat insulation layer. The module adhesive layer can be located close to the second light guide plate. The module heat insulation layer can be located close to the optical element. The module filter layer can be located between the module adhesive layer and the module heat insulation layer.

[0015] The optical element may include a camera and a sensor. The module sheet may include a first hole corresponding to the camera and a second hole corresponding to the sensor. The first hole may penetrate through the module adhesive layer, the module filter layer, and the module heat insulation layer. The second hole may penetrate through the module adhesive layer and the module heat insulation layer. The module filter layer may include a region overlapping with the second hole.

[0016] A backlight sheet can be located between the first light guide plate and the liquid crystal panel. The backlight sheet may include a sheet hole overlapping with the sensing region of the liquid crystal panel.

[0017] The second light source element, the second light guide plate, and the optical element can be surrounded by a light-shielding cover.

[0018] The display device according to the technical idea of the present invention for achieving the other problems to be solved includes a backlight unit. The backlight unit includes a first light guide plate, a first light source element, and a cover bottom. The first light source element is located on one side surface of the first light guide plate. The cover bottom houses the first light source element and the first light guide plate. A liquid crystal panel is located on the first light guide plate. The liquid crystal panel includes a sensing region. The cover bottom includes a cover hole that overlaps with the sensing region of the liquid crystal panel. A light source module is located on the cover bottom. The light source module includes a second light guide plate, a second light source element, and an optical element. The second light guide plate overlaps with the sensing region of the liquid crystal panel. The second light guide plate includes an upper surface facing the cover bottom. The second light source element is located on at least one of the side surfaces perpendicular to the upper surface of the second light guide plate. The optical element spaced apart from the second light source element is located on the optical path of the light passing through the first light guide plate and the second light guide plate.

[0019] A fixing tape may be located between the cover bottom of the backlight unit and the light source module. The cover bottom and the light source module may be in contact with the fixing tape. The fixing tape may surround the cover hole.

[0020] The second light source element may include a module circuit board and a module light source. The module light source can be mounted on one side end of the module circuit board. The second light guide plate may include an inclined surface that overlaps with the module circuit board outside the module light source.

[0021] A reflecting plate may be located between the cover bottom and the first light guide plate. The reflecting plate may include a through hole that overlaps with the sensing region of the liquid crystal panel.

[0022] A backlight sheet may be located between the first light guide plate and the liquid crystal panel. The backlight sheet may include a base substrate and an optical member. The optical member may be located on the base substrate. The optical member may be located outside the region of the base substrate that overlaps with the sensing region of the liquid crystal panel.

[0023] The second light guide plate may include a lower surface facing the upper surface. The optical element may be located on the lower surface of the second light guide plate. A semi-transmissive surface inclined with respect to the upper and lower surfaces may be located within the second light guide plate.

Advantages of the Invention

[0024] The display device according to the technical idea of the present invention includes a backlight unit located between an optical module and a liquid crystal panel. The backlight unit includes a backlight light guide plate located between the optical module and the liquid crystal panel. The optical module includes a module light guide plate overlapping with a sensing region of the liquid crystal panel, a module light source element located on at least one side of the module light guide plate, and an optical element spaced apart from the module light source element. The optical element may be located on a path of external light that has passed through the backlight light guide plate and the module light guide plate. Therefore, the display device according to the technical idea of the present invention can provide light having the same luminance as the active region of the liquid crystal panel to the sensing region of the liquid crystal panel. That is, the display device according to the technical idea of the present invention can prevent a luminance deviation between the active region and the sensing region. Therefore, the display device according to the technical idea of the present invention can sense external light without a decrease in the quality of the image provided to the user.

Brief Description of the Drawings

[0025]

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Best Mode for Carrying Out the Invention

[0026] The detailed matters regarding the object, technical configuration, and the resulting effects of this specification will be more clearly understood from the following detailed description with reference to the drawings showing the embodiments of this specification. Here, the embodiments of this specification are provided to fully convey the technical idea of this specification to those skilled in the art, so this specification is not limited to the embodiments described below and can be embodied in other forms.

[0027] Also, parts denoted by the same reference numerals throughout the specification mean the same components. In the drawings, the lengths and thicknesses of layers or regions may be exaggerated for the sake of convenience. Further, when it is described that a first component is "above" a second component, it includes not only the case where the first component is located directly above and in contact with the second component, but also the case where a third component is located between the first component and the second component.

[0028] Here, terms such as first, second, etc. are for explaining various components and are used for the purpose of distinguishing one component from another. However, within the scope not departing from the technical idea of this specification, the first component and the second component can be arbitrarily named by those skilled in the art for convenience.

[0029] The terms described in the specification of this specification are only used for explaining specific embodiments and are not intended to limit the technical idea of this specification. For example, a component expressed in the singular includes a plurality of components unless it clearly means only the singular in the context. Also, in the specification of this specification, terms such as "including" or "having" are intended to specify the existence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should be understood not to preclude in advance the possibility of the existence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0030] Furthermore, unless otherwise defined, all terms used here, including technical or scientific terms, have the same meaning as generally understood by those having ordinary knowledge in the technical field to which this specification belongs. Terms such as those defined in commonly used dictionaries should be interpreted to have a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or overly formal meaning unless clearly defined in the specification of this specification.

[0031] (Embodiment) FIG. 1 is a diagram schematically showing a display device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line I-I' and line II-II' of FIG. 1. FIG. 3 is an enlarged view of the K region of FIG. 2. FIG. 4 is a cross-sectional view taken along line III-III' of FIG. 1.

[0032] Referring to FIGS. 1 to 4, the display device according to an embodiment of the present invention may include a liquid crystal panel 100, a backlight unit 200, and an optical module 300. The liquid crystal panel 100 may generate an image provided to a user. For example, the liquid crystal panel 100 may include an active area AA where a number of pixel areas are located, and a bezel area BZ located outside the active area AA. The bezel area BZ may be an area extending from the active area AA. The bezel area BZ may be arranged to surround a part or all of the active area AA. The liquid crystal panel 100 may include a liquid crystal layer overlapping with the pixel area. For example, the liquid crystal layer of the liquid crystal panel 100 may include liquid crystal in an IPS mode or liquid crystal in a TN mode. Various signals may be applied to each pixel area via signal wirings. For example, liquid crystal located within a partial area of the liquid crystal layer overlapping with each pixel area may be rotated by a vertical electric field or a horizontal electric field formed within the pixel area via the signal wiring. Therefore, the display device according to an embodiment of the present invention may generate images of various colors by the light emitted from the active area AA of the liquid crystal panel 100.

[0033] The backlight unit 200 may supply light to the liquid crystal panel 100. For example, the backlight unit 200 may include a backlight light source element 210, a backlight light guide plate 220, a backlight reflector 230, and a backlight sheet 240.

[0034] The backlight light source element 210 may supply light to the liquid crystal panel 100 via the backlight light guide plate 220. For example, the backlight light source element 210 may be located on one side surface of the backlight light guide plate 220. The liquid crystal panel 100 may be located on the upper surface of the backlight light guide plate 220. The backlight light source element 210 may include a backlight circuit board 211 and a backlight light source 212 mounted on the backlight circuit board 211. The backlight light source 212 may be a self-luminous element capable of generating and emitting light. For example, the backlight light source 212 may include an LED.

[0035] The backlight reflector 230 may be located on the lower surface of the backlight light guide plate 220. The lower surface of the backlight light guide plate 220 may face the upper surface of the backlight light guide plate 220. For example, the backlight light guide plate 220 may be located between the backlight reflector 230 and the liquid crystal panel 100. The backlight reflector 230 may include a substance capable of reflecting light. For example, the backlight reflector 230 may include a metal such as aluminum (Al) or silver (Ag). Therefore, in the display device according to an embodiment of the present invention, the light emitted through the lower surface of the backlight light guide plate 220 can be reflected by the backlight reflector 230 in the direction of the liquid crystal panel 100. Therefore, in the display device according to an embodiment of the present invention, the amount of light supplied to the liquid crystal panel 100 by the backlight unit 200 can be increased.

[0036] The backlight sheet 240 may be located between the backlight light guide plate 220 and the liquid crystal panel 100. The light supplied to the liquid crystal panel 100 through the backlight light guide plate 220 may have a generally uniform luminance by the backlight sheet 240. For example, the backlight sheet 240 may have a laminated structure of a prism sheet 241 and a diffusion sheet 242.

[0037] The prism sheet 241 may include a prism member 241p located on a first base substrate 241s. The prism member 241p may have various shapes. For example, the cross-sectional shape of the prism member 241p may have a shape in which triangles are repeatedly arranged. The first base substrate 241s may include a transparent substance. For example, the first base substrate 241s may include plastic or glass. The prism member 241p may include a transparent substance. For example, the prism member 241p may be formed of the same substance as the first base substrate 241s. The interface between the first base substrate 241s and the prism member 241p cannot be recognized. For example, the prism member 241p may be formed integrally with the first base substrate 241s.

[0038] The diffusion sheet 242 may include diffusion particles 242p dispersed on the second base substrate 242s. The second base substrate 242s may include a transparent substance. For example, the second base substrate 242s may include plastic or glass. The second base substrate 242s may include the same substance as the first base substrate 241s. The diffusion particles 242p may have various sizes. Thus, the display device according to an embodiment of the present invention can improve the uniformity of light supplied to the liquid crystal panel 100 through the backlight sheet 240. The diffusion particles 242p may be fixed on the second base substrate 242s by a transparent adhesive such as resin.

[0039] The backlight unit 200 may include a cover bottom 250 for accommodating the backlight light source element 210, the backlight light guide plate 220, the backlight reflector 230, and the backlight sheet 240. The cover bottom 250 may include an insulating substance. For example, the cover bottom 250 may include plastic, glass, or ceramic. The cover bottom 250 may include a bottom surface and a side wall protruding from an edge of the bottom surface. The backlight reflector 230 may be located between the backlight light guide plate 220 and the bottom surface of the cover bottom 250. The backlight light source element 210, the backlight light guide plate 220, and the backlight sheet 240 may be located within a space formed by the side wall of the cover bottom 250. For example, the side wall of the cover bottom 250 may surround at least a part or all of at least one of the backlight light source element 210, the backlight light guide plate 220, and the backlight sheet 240.

[0040] The backlight unit 200 may include a middle frame 260 for supporting the liquid crystal panel 100. The middle frame 260 may be coupled to the cover bottom 250. For example, the middle frame 260 may include a coupling region extending between the cover bottom 250 and the backlight light guide plate 220. The backlight light source element 210 may be fixed to the coupling region of the middle frame 260. For example, the backlight light source element 210 may be attached to the coupling region of the middle frame 260 by an adhesive member or a fixing member. The fixing member may include a bolt or a clip. The middle frame 260 may include a seating region extending between the backlight sheet 240 and the liquid crystal panel 100. The seating region of the middle frame 260 may overlap with the edge of the backlight sheet 240. For example, the seating region of the middle frame 260 may overlap with a part or all of the bezel region BZ of the liquid crystal panel 100. The active region AA of the liquid crystal panel 100 may not overlap with the seating region of the middle frame 260. For example, the central region of the backlight sheet 240 may be exposed by the middle frame 260. The seating region of the middle frame 260 may be in direct contact with the backlight sheet 240. Thus, the display device according to an embodiment of the present invention may reduce or prevent the floating of the backlight sheet 240 by the middle frame 260.

[0041] The optical module 300 can sense external light via the liquid crystal panel 100 and the backlight unit 200. For example, the optical module 300 can be located on the cover bottom 250 of the backlight unit 200. The liquid crystal panel 100 may include a sensing area HA for sensing external light. The sensing area HA may be located within the active area AA. For example, the backlight reflector 230 includes a through hole 230h that overlaps with the sensing area HA of the liquid crystal panel 100, the backlight sheet 240 includes a sheet hole 240h that overlaps with the sensing area HA of the liquid crystal panel 100, and the cover bottom 250 may include a cover hole 250h that overlaps with the sensing area HA of the liquid crystal panel 100. The first base substrate 241s and the second base substrate 242s of the backlight sheet 240 do not have to overlap with the sensing area HA of the liquid crystal panel 100. The optical module 300 may include a module light source element 310, a module light guide plate 320, a module reflector 330, a module sheet 340, and an optical element 350.

[0042] FIG. 5 is a diagram showing a display device according to an embodiment of the present invention, and shows the module light source element 310, the module light guide plate 320, and the module reflector 330 of the optical module 300. FIG. 6 is a diagram showing a display device according to an embodiment of the present invention, and shows the module light guide plate 320, the module sheet 340, and the optical element 350 of the optical module 300.

[0043] As shown in FIGS. 2 and 4 to 6, the module light source element 310 is located on the opposing side surface of the module light guide plate 320, and the module light guide plate 320 may overlap with the sensing region HA of the liquid crystal panel 100. The side surface of the module light guide plate 320 where the module light source element 310 is located may be perpendicular to the upper surface of the module light guide plate 320 facing the backlight light guide plate 220. The module light guide plate 320 may include an inclined surface 320c that overlaps with the sensing region HA of the liquid crystal panel 100. For example, the module light source element 310 may be located on the upper surface of the module light guide plate 320 and the side surface perpendicular to the inclined surface 320c. Therefore, the display device according to an embodiment of the present invention can supply the light emitted from the module light source element 310 to the sensing region HA of the liquid crystal panel 100 by the inclined surface 320c of the module light guide plate 320.

[0044] The module light source element 310 may include a module circuit board 311 and a module light source 312. Each module light source 312 may be a self-luminous element that can generate and emit light. For example, each module light source 312 may include an LED, an OLED, or a micro LED. The module light source 312 may be the same element as the backlight light source 212. Each module light source 312 can be mounted on one side end of the module circuit board 311. For example, the module light sources 312 can be turned on / turned off simultaneously. The module light sources 312 can be driven simultaneously with the backlight light source 212. For example, the display device according to an embodiment of the present invention can generate an image using the light emitted from the backlight light source element 210 and the light emitted from the module light source element 310 by the liquid crystal panel 100. That is, when the liquid crystal panel 100 generates an image, the display device according to an embodiment of the present invention can supply light to the sensing region HA of the liquid crystal panel 100 by the module light source element 310. Therefore, when the liquid crystal panel 100 generates an image, the light supplied to the sensing region HA can have substantially the same luminance as the light supplied to the active region AA in the display device according to an embodiment of the present invention. Therefore, the display device according to an embodiment of the present invention can prevent a decrease in image quality due to a luminance deviation between the active region AA and the sensing region HA.

[0045] The module reflector 330 may be located on the inclined surface 320c of the module light guide plate 320. The module reflector 330 may include a material capable of reflecting light. For example, the module reflector 330 may include metals such as aluminum (Al) and silver (Ag). The module reflector 330 may include the same material as the backlight reflector 230. Thus, the display device according to an embodiment of the present invention can reflect the light emitted through the inclined surface 320c of the module light guide plate 320 inward of the module light guide plate 320 by the module reflector 330. Thus, the display device according to an embodiment of the present invention can increase the amount of light supplied to the sensing region HA of the liquid crystal panel 100 through the module light guide plate 320.

[0046] The module sheet 340 may be located on the side surface facing the inclined surface 320c of the module light guide plate 320. The optical element 350 may be located on the module sheet 340. For example, the display device according to an embodiment of the present invention can supply external light applied to the module light guide plate 320 through the sensing region HA of the liquid crystal panel 100 and the backlight light guide plate 220 to the optical element 350 through the module sheet 340. The external light applied through the sensing region HA of the liquid crystal panel 100 may pass through the sheet hole 240h of the backlight sheet 240. Thus, the display device according to an embodiment of the present invention can prevent the external light supplied to the optical element 350 from being refracted and / or diffused by the backlight sheet 240. That is, the display device according to an embodiment of the present invention can sense the external light by the optical element 350 without distortion by the backlight sheet 240. Thus, the display device according to an embodiment of the present invention can improve the sensing characteristics of the external light.

[0047] The module sheet 340 may be positioned between the module light guide plate 320 and the optical element 350. For example, the module sheet 340 may have a laminated structure of a module adhesive layer 341, a module filter layer 342, and a module heat insulation layer 343. The module adhesive layer 341 may be positioned close to the module light guide plate 320. The module adhesive layer 341 may be in direct contact with the module light guide plate 320. For example, the module sheet 340 may be attached to the module light guide plate 320 by the module adhesive layer 341. The module heat insulation layer 343 may be positioned close to the optical element 350. Thus, the display device according to an embodiment of the present invention may reduce or prevent damage and deformation of the module sheet 340 due to heat generated by the operation of the optical element 350. The module filter layer 342 may be positioned between the module adhesive layer 341 and the module heat insulation layer 343. The module filter layer 342 may reduce or prevent the diffusion of visible light among the light traveling in the direction of the optical element 350 through the module light guide plate 320. Here, visible light means light that can be recognized by the human eye. For example, light having a wavelength range of approximately 400 nm to 700 nm cannot pass through the module filter layer 342. Thus, the display device according to an embodiment of the present invention may prevent distortion of the light supplied to the optical element 350 due to irregular reflection and / or regular reflection of visible light.

[0048] The optical element 350 may include an element capable of sensing external light. For example, the optical element 350 may include a camera 351 and / or an IR sensor 352. The module sheet 340 may include first holes 341a, 342a, 343a corresponding to the camera 351 and second holes 341b, 343b corresponding to the IR sensor 352. The first holes 341a, 342a, 343a of the module sheet 340 may penetrate through the module adhesive layer 341, the module filter layer 342, and the module heat insulation layer 343. For example, the first holes 341a, 342a, 343a of the module sheet 340 may be composed of a first hole 341a penetrating through the module adhesive layer 341, a filter hole 342a penetrating through the module filter layer 342, and a first module hole 343a penetrating through the module heat insulation layer 343. The second holes 341b, 343b of the module sheet 340 may penetrate through the module adhesive layer 341 and the module heat insulation layer 343. The module filter layer 342 may include a filter region 342f that overlaps with the second holes 341b, 343b of the module sheet 340. For example, the second holes 341b, 343b of the module sheet 340 may be composed of a second hole 341b penetrating through the module adhesive layer 341 and a second module hole 343b penetrating through the module heat insulation layer 343. Therefore, the display device according to an embodiment of the present invention may provide external light that has passed through the first holes 341a, 342a, 343a of the module sheet 340 to the camera 351 and provide external light that has passed through the second holes 341b, 343b of the module sheet 340 to the IR sensor 352. That is, the display device according to an embodiment of the present invention supplies external light including visible light to the camera 351, but the visible light of the external light traveling to the IR sensor 352 may be blocked by the filter region 342f of the module filter layer 342. Therefore, the display device according to an embodiment of the present invention may reduce or prevent a decrease in the sensing characteristics of the IR sensor 352 due to visible light.

[0049] The optical module 300 can be fixed on the backlight unit 200. For example, a fixing tape 400 can be positioned between the cover bottom 250 and the optical module 300. The fixing tape 400 can be in direct contact with the cover bottom 250 and the optical module 300. For example, the optical module 300 can be attached to the cover bottom 250 by the fixing tape 400. Thus, the display device according to an embodiment of the present invention can reduce or prevent the floating of the optical module 300. Thus, the display device according to an embodiment of the present invention can improve the external light sensing characteristics of the optical element 350 of the optical module 300.

[0050] As a result, the display device according to an embodiment of the present invention includes a liquid crystal panel 100 positioned on the upper surface of the backlight light guide plate 220 and an optical module 300 positioned on the lower surface of the backlight light guide plate 220. The liquid crystal panel 100 includes a sensing region HA for sensing external light. The optical module 300 can include a module light guide plate 320 that overlaps with the sensing region HA, a module light source element 310 positioned on a side surface perpendicular to the inclined surface 320c of the module light guide plate 320, and an optical element 350 positioned to face the inclined surface 320c of the module light guide plate 320. Thus, in the display device according to an embodiment of the present invention, when the liquid crystal panel 100 generates an image, the light supplied to the sensing region HA of the liquid crystal panel 100 by the module light source element 310 that is turned on / turned off simultaneously with the backlight light source element 210 can have the same luminance as the light supplied to the active region AA of the liquid crystal panel 100 by the backlight light source element 210. Also, in the display device according to an embodiment of the present invention, when the liquid crystal panel 100 does not generate an image, the external light applied through the sensing region HA of the liquid crystal panel 100, the backlight light guide plate 220, and the module light guide plate 320 can be sensed by the optical element 350. Thus, the display device according to an embodiment of the present invention can sense external light without degrading the quality of the image.

[0051] The display device according to an embodiment of the present invention is described as having the optical element 350 including the camera 351 and the IR sensor 352. However, in the display device according to another embodiment of the present invention, the optical element 350 may include various elements. For example, in the display device according to another embodiment of the present invention, the optical element 350 may include one of the camera 351 and the IR sensor 352. Also, in the display device according to another embodiment of the present invention, the optical element 350 may further include at least one of various sensors. For example, in the display device according to another embodiment of the present invention, the optical element 350 may include at least one of a motion sensor, an illuminance sensor, and an ultrasonic sensor. Therefore, the display device according to another embodiment of the present invention can improve the degree of freedom in the configuration of the optical element 350.

[0052] The display device according to an embodiment of the present invention is described as having each module light source 312 being the same as the backlight light source 212. However, in the display device according to another embodiment of the present invention, the type and number of each module light source 312 can be determined by the luminance of the light supplied to the active area AA of the liquid crystal panel 100 by the backlight light source 212. Also, in the display device according to another embodiment of the present invention, the type and number of each module light source 312 can be determined by the area ratio between the active area AA and the sensing area HA of the liquid crystal panel 100. That is, in the display device according to another embodiment of the present invention, when the liquid crystal panel 100 generates an image, the type and number of each module light source 312 can be adjusted so that the luminance of the light supplied to the sensing area HA of the liquid crystal panel 100 is substantially the same as the luminance of the light supplied to the active area AA of the liquid crystal panel 100. Therefore, the display device according to another embodiment of the present invention can effectively prevent the deterioration of the image quality due to the luminance deviation between the active area AA and the sensing area HA of the liquid crystal panel 100.

[0053] According to another embodiment of the present invention, in the display device, the module heat insulation layer 343 may contain a substance capable of absorbing light. For example, the module heat insulation layer 343 may contain a black dye such as carbon black. The module heat insulation layer 343 may have a multilayer structure. For example, the module heat insulation layer 343 may have a double-layer structure of a heat insulation layer and an absorption layer. Therefore, in the display device according to another embodiment of the present invention, the light traveling through a partial region of the module sheet 340 that does not overlap with the optical element 350 can be blocked by the module heat insulation layer 343. Therefore, the display device according to another embodiment of the present invention can improve the external light sensing characteristics.

[0054] In the display device according to an embodiment of the present invention, it is described that the optical element 350 is located near the central portion of the backlight unit 200. However, in the display device according to another embodiment of the present invention, the optical element 350 can be arranged at various positions. For example, as shown in FIG. 7, in the display device according to another embodiment of the present invention, the optical element 350 can be located on the side surface of the module light guide plate 320 that faces the outside of the backlight unit 200. The inclined surface of the module light guide plate 320 can be located near the central portion of the backlight unit 200. Therefore, the display device according to another embodiment of the present invention can improve the degree of freedom with respect to the position of the optical element 350.

[0055] The display device according to another embodiment of the present invention can block the external light that has not passed through the liquid crystal panel 100 and the backlight unit 200 from traveling in the direction of the module light guide plate 320. For example, as shown in FIG. 8, the display device according to another embodiment of the present invention may include a light-shielding cover 360 that surrounds the module light source element 310, the module light guide plate 320, the module sheet 340, and the optical element 350 in the optical module 300. The light-shielding cover 360 can be attached to the cover bottom 250 by the fixing tape 400. Therefore, the display device according to another embodiment of the present invention can prevent the optical element 350 from sensing the external light that has not passed through the liquid crystal panel 100 and the backlight unit 200. That is, the display device according to another embodiment of the present invention can prevent the sensing of unintended external light. Therefore, the display device according to another embodiment of the present invention can effectively improve the sensing characteristics of the external light by the sensing region HA of the liquid crystal panel 100.

[0056] The display device according to an embodiment of the present invention is described as having the prism member 241p containing the same material as the first base substrate 241s. However, in the display device according to another embodiment of the present invention, the first base substrate 241s may contain a material different from that of the prism member 241p. For example, the transmittance of the first base substrate 241s may be higher than the transmittance of the prism member 241p. Therefore, the display device according to another embodiment of the present invention can improve the degree of freedom in the configuration of the prism sheet 241.

[0057] In a display device according to another embodiment of the present invention, at least one of the first base substrate 241s and the second base substrate 242s may include a region located outside the optical member, for example, the prism member 241p or the diffusion particles 242p. For example, as shown in FIG. 9, in a display device according to another embodiment of the present invention, the first base substrate 241s and the second base substrate 242s can extend in the inner direction of the sheet hole 240h. Each of the first base substrate 241s and the second base substrate 242s may include a region overlapping with the sensing region of the liquid crystal panel. The sheet hole 240h may be a region where the prism member 241p and the diffusion particles 242p are not formed. That is, in a display device according to another embodiment of the present invention, the steps of forming holes in the first base substrate 241s and forming holes in the second base substrate 242s may be omitted. Therefore, the display device according to another embodiment of the present invention can improve the efficiency of the steps for forming the backlight sheet 240.

[0058] As shown in FIG. 10, in a display device according to another embodiment of the present invention, a prism member 241p is formed on the entire surface of a first base substrate 241s, diffusion particles 242p are formed on the entire surface of a second base substrate 242s, and a partial region of the prism member 241p that overlaps with the sensing region of the liquid crystal panel is covered by a first refractive index matching member 241m, and a partial region of the diffusion particles 242p that overlaps with the sensing region of the liquid crystal panel can be covered by a second refractive index matching member 242m. The first refractive index matching member 241m may include a substance that can cancel out the refraction by the prism member 241p. The second refractive index matching member 242m may include a substance that can cancel out the refraction by the diffusion particles 242p. Therefore, in the display device according to another embodiment of the present invention, a sheet hole 240h through which external light passes without being refracted by the prism member 241p and the diffusion particles 242p can be formed by the first refractive index matching member 241m and the second refractive index matching member 242m. That is, in the display device according to another embodiment of the present invention, the step of removing the prism member 241p formed on a partial region of the first base substrate 241s that overlaps with the sensing region of the liquid crystal panel and the step of removing the diffusion particles 242p formed on a partial region of the second base substrate 242s that overlaps with the sensing region of the liquid crystal panel can be omitted. Therefore, the display device according to another embodiment of the present invention can effectively improve the process efficiency.

[0059] The display device according to an embodiment of the present invention is described as having a module circuit board 311 positioned parallel to the upper surface of a module light guide plate 320 facing a backlight light guide plate 220, and a module light source 312 mounted at an end of the module circuit board 311. However, in the display device according to another embodiment of the present invention, the module light source 312 can be arranged closer to the center of the module light guide plate 320. For example, as shown in FIG. 11, in the display device according to another embodiment of the present invention, a stepped portion 320d can be formed at the upper end of the side surface of the module light guide plate 320 facing each module light source 312. The module circuit board 311 can extend along the stepped portion 320d of the module light guide plate 320. Therefore, the display device according to another embodiment of the present invention can prevent a reduction in efficiency due to the position of the module light source 312. Further, the display device according to another embodiment of the present invention can prevent a luminance deviation in the active region AA and the sensing region HA due to a decrease in the efficiency of the module light source 312.

[0060] According to another embodiment of the present invention, the module light guide plate 320 may have various forms for the positional movement of the module light source 312. For example, in the display device according to another embodiment of the present invention, a partial region of the module light guide plate 320 that overlaps with the module light source element 310 is recessed to form a groove in the module light guide plate 320, and the module light source element 310 can be inserted into the groove of the module light guide plate 320. Also, as shown in FIG. 12, in the display device according to another embodiment of the present invention, the side surface of the module light guide plate 320 facing each module light source 312 may include an inclined region 320s. The inclined region 320s of the module light guide plate 320 may overlap with the module circuit board 311 outside the module light source 312. For example, the module circuit board 311 may be in direct contact with the inclined region 320s of the module light guide plate 320. Therefore, the display device according to another embodiment of the present invention can prevent damage to the module circuit board 311 due to the shape of the module light guide plate 320. That is, the display device according to another embodiment of the present invention can prevent a reduction in efficiency due to the position of the module light source 312 without damaging the module circuit board 311. Therefore, the display device according to another embodiment of the present invention can prevent a luminance deviation between the active region AA and the sensing region HA.

[0061] The display device according to an embodiment of the present invention is described such that the module light source element 310 and the optical element 350 are located outside the sensing region HA. However, as shown in FIG. 13, in the display device according to another embodiment of the present invention, the optical element 350 may be located on the lower surface of the module light guide plate 320. The lower surface of the module light guide plate 320 may face the upper surface of the module light guide plate 320. A semi-transmissive surface 320sr inclined with respect to the upper and lower surfaces of the module light guide plate 320 may be located within the module light guide plate 320. Therefore, in the display device according to another embodiment of the present invention, when the liquid crystal panel 100 generates an image, the light emitted from the module light source element 310 can be reflected by the semi-transmissive surface 320sr of the module light guide plate 320 in the direction of the sensing region HA of the liquid crystal panel 100. Also, in the display device according to another embodiment of the present invention, when the liquid crystal panel 100 does not generate an image, the external light applied through the sensing region HA of the liquid crystal panel 100 and the backlight light guide plate 220 can be supplied to the optical element 350 through the semi-transmissive surface 320sr of the module light guide plate 320. That is, the display device according to another embodiment of the present invention can prevent a deterioration in the quality of the image due to the sensing region HA and effectively improve the degree of freedom with respect to the position of the optical element 350.

[0062] The display device according to an embodiment of the present invention is described as having a module light guide plate 320 with an inclined surface 320c. However, in the display device according to another embodiment of the present invention, the module light guide plate 320 may have various shapes so as to supply external light applied through the sensing region HA of the liquid crystal panel 100 and the backlight light guide plate 220 to the optical element 350. For example, as shown in FIG. 14, in the display device according to another embodiment of the present invention, the module light guide plate 320 may have a plate shape with a certain curvature. For example, in the display device according to another embodiment of the present invention, external light applied through the sensing region HA of the liquid crystal panel 100 and the backlight light guide plate 220 can be reflected in the direction of the optical element 350 by a refractive index difference on the curved surface of the module light guide plate 320. That is, in the display device according to another embodiment of the present invention, the module reflector can be omitted. Therefore, in the display device according to another embodiment of the present invention, the degree of freedom with respect to the shape of the module light guide plate 320 that supplies external light applied through the sensing region HA of the liquid crystal panel 100 and the backlight light guide plate 220 to the optical element 350 can be improved.

Description of Reference Numerals

[0063] 100 Liquid crystal panel 200 Backlight unit 210 Backlight light source element 220 Backlight light guide plate 300 Optical module 310 Module light source element 320 Module light guide plate 340 Module sheet 390 Optical element

Claims

1. A backlight unit including a first light guide plate and a first light source element, a liquid crystal panel located on the upper surface of the first light guide plate and including a sensing region, and an optical module located on the lower surface of the first light guide plate and including a second light guide plate, a second light source element, and an optical element, wherein the upper surface of the second light guide plate overlaps with the sensing region of the liquid crystal panel, and the first light guide plate includes a region located between the upper surface of the second light guide plate and the liquid crystal panel, a display device.

2. The display device according to claim 1, wherein the second light source element and the optical element are located outside the sensing region.

3. The display device according to claim 1, wherein the second light source element is located on two opposite side surfaces among the side surfaces perpendicular to the upper surface of the second light guide plate.

4. The backlight unit includes a cover bottom for housing the first light guide plate and the first light source element, and the cover bottom includes a cover hole overlapping with the sensing region of the liquid crystal panel, the display device according to claim 1.

5. The optical element is located on a first side surface perpendicular to the upper surface of the second light guide plate, and the second light guide plate includes an inclined surface facing the first side surface, the display device according to claim 1.

6. The display device according to claim 5, wherein the optical module further includes a module reflector located on the inclined surface of the second light guide plate.

7. The optical module includes a module sheet located between the optical element and the second light guide plate, and the module sheet includes at least one hole corresponding to the optical element, the display device according to claim 1.

8. The display device according to claim 7, wherein the module sheet includes a module adhesive layer located close to the second light guide plate and a module heat insulation layer located close to the optical element.

9. The display device according to claim 8, wherein the module sheet further includes a module filter layer located between the module adhesive layer and the module heat insulation layer.

10. The optical element includes a camera and a sensor, the module sheet includes a first hole corresponding to the camera and a second hole corresponding to the sensor, and the first hole penetrates through the module adhesive layer, the module heat insulation layer, and the module filter layer. The second hole penetrates the module adhesive layer and the module heat insulation layer, The display device according to claim 9, wherein the module filter layer includes a region corresponding to the second hole.

11. The backlight unit includes a backlight sheet positioned between the first light guide plate and the liquid crystal panel, The display device according to claim 1, wherein the backlight sheet includes a sheet hole that overlaps with the sensing region of the liquid crystal panel.

12. The display device according to claim 1, wherein the optical module includes a light-shielding cover surrounding the second light source element, the second light guide plate, and the optical element.

13. The display device according to claim 1, wherein the second light source element and the optical element are positioned on different surfaces of the second light guide plate.

14. When the liquid crystal panel generates an image, the light supplied to the sensing region by the second light source element has the same luminance as the light supplied to the active region of the liquid crystal panel by the first light source element. The display device according to claim 1.

15. A backlight unit including a first light source element positioned on one side surface of the first light guide plate and a cover bottom that houses the first light source element and the first light guide plate, A liquid crystal panel positioned on the first light guide plate of the backlight unit and including a sensing region, A light source module including a second light guide plate including an upper surface facing the cover bottom, a second light source element positioned on at least one of side surfaces perpendicular to the upper surface of the second light guide plate, and an optical element spaced apart from the second light source element, The cover bottom includes a cover hole that overlaps with the sensing region of the liquid crystal panel, The second light guide plate of the light source module overlaps with the sensing region of the liquid crystal panel, The optical element is positioned on a path of light that has passed through the first light guide plate and the second light guide plate. A display device.

16. The display device according to claim 15, further including a fixing tape that contacts the cover bottom of the backlight unit and the light source module and passes through the cover hole.

17. The second light source element includes a module circuit board and a module light source mounted on the module circuit board, The display device according to claim 15, wherein the second light guide plate includes an inclined surface that overlaps the module circuit board outside the module light source.

18. The backlight unit includes a reflector positioned between the cover bottom and the first light guide plate, The display device according to claim 15, wherein the reflector includes a through hole that overlaps the sensing region of the liquid crystal panel.

19. The backlight unit includes a backlight sheet positioned between the first light guide plate and the liquid crystal panel, The backlight sheet includes a base substrate and an optical member positioned on the base substrate, The base substrate includes a region that overlaps the sensing region of the liquid crystal panel, The display device according to claim 15, wherein the optical member is positioned outside the region of the base substrate that overlaps the sensing region.

20. The optical element is positioned on the lower surface facing the upper surface of the second light guide plate, In the second light guide plate, a semi-transmissive surface is positioned so as to be inclined with respect to the upper surface and the lower surface of the second light guide plate. The display device according to claim 15.

Images