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] The present specification relates to a display device in which an optical module is located on one side of a liquid crystal panel. [Background technology]

[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 backlight light source elements positioned on one side of a backlight light guide plate. The liquid crystal panel may be positioned 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 portion of the liquid crystal panel. For example, the liquid crystal panel may include an active area overlapping the backlight light guide plate and a sensing area overlapping the light source module. Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a display device that can prevent degradation of the quality of an image provided to a user due to a sensing area disposed within an active area.

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

[0006] Yet another problem to be solved by the present specification is to provide a display device in which an optical module can sense external light through a sensing area of ​​a liquid crystal panel without degrading image quality.

[0007] The problems to be solved by the present invention are not limited to those mentioned above, and problems not mentioned here will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0008] A display device according to the technical idea of ​​the present specification to achieve the above-mentioned problem 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 an upper surface of the first light guide plate. The liquid crystal panel includes a sensing region. A light source module is located on a 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 the sensing region of the liquid crystal panel. The first light guide plate includes an area 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 area.

[0010] The second light source elements may be located on two opposing side surfaces of the second light guide plate that are perpendicular to the top surface of the second light guide plate.

[0011] The first light guide plate and the first light source element may be accommodated by a bottom cover, and the bottom cover may include a cover hole overlapping a sensing area of ​​the liquid crystal panel.

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

[0014] A module sheet may 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 may be located near the second light guide plate. The module heat insulation layer may be located near the optical element. The module filter layer may 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 the module adhesive layer, the module filter layer, and the module heat insulating layer. The second hole may penetrate the module adhesive layer and the module heat insulating layer. The module filter layer may include an area overlapping with the second hole.

[0016] A backlight sheet may be disposed between the first light guide plate and the liquid crystal panel, and the backlight sheet may include a sheet hole overlapping the sensing area of ​​the liquid crystal panel.

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

[0018] To achieve another object of the present invention, a display device according to the technical concept of the present invention includes a backlight unit. The backlight unit includes a first light guide plate, a first light source element, and a bottom cover. The first light source element is located on one side of the first light guide plate. The bottom cover accommodates 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 area. The bottom cover includes a cover hole overlapping the sensing area of ​​the liquid crystal panel. A light source module is located on the bottom cover. 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 the sensing area of ​​the liquid crystal panel. The second light guide plate has an upper surface facing the bottom cover. 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 from the second light source element is located on the path of light passing through the first and second light guide plates.

[0019] A fixing tape may be positioned 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, and 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 may be mounted on one side of the module circuit board. The second light guide plate may include an inclined surface that overlaps the module circuit board outside the module light source.

[0021] A reflector may be disposed between the bottom cover and the first light guide plate, and the reflector may include a through-hole overlapping the sensing region of the liquid crystal panel.

[0022] A backlight sheet may be positioned 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 positioned on the base substrate. The optical member may be positioned outside an area of ​​the base substrate that overlaps with a sensing area of ​​the liquid crystal panel.

[0023] The second light guide plate may include a lower surface opposite to the upper surface, the optical element may be located on the lower surface of the second light guide plate, and a semi-transmissive surface may be located within the second light guide plate and tilted relative to the upper and lower surfaces. [Effects of the Invention]

[0024] A display device according to the present invention includes a backlight unit positioned between an optical module and a liquid crystal panel. The backlight unit includes a backlight light guide plate positioned between the optical module and the liquid crystal panel. The optical module includes a module light guide plate overlapping a sensing region of the liquid crystal panel, a module light source element positioned on at least one side of the module light guide plate, and an optical element spaced from the module light source element. The optical element may be positioned on a path of external light passing through the backlight light guide plate and the module light guide plate. Therefore, the display device according to the present invention can provide light with the same brightness 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 present invention can prevent brightness deviation between the active region and the sensing region. Therefore, the display device according to the present invention can sense external light without degrading the quality of the image provided to a user. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a diagram schematically illustrating a display device according to an embodiment of the present invention. [Figure 2] 2 is a cross-sectional view taken along lines II' and II-II' in FIG. 1. [Figure 3] FIG. 3 is an enlarged view of the K region in FIG. 2. [Figure 4] FIG. 2 is a cross-sectional view taken along line III-III' in FIG. [Figure 5] 2 is a diagram illustrating a module light source element, a module light guide plate, and a module reflector of an optical module in a display device according to an embodiment of the present invention; [Figure 6]2 is a diagram illustrating a module light guide plate, a module sheet, and an optical element of an optical module in a display device according to an embodiment of the present invention; [Figure 7] FIG. 10 is a diagram illustrating a display device according to another embodiment of the present invention. [Figure 8] FIG. 10 is a diagram illustrating a display device according to another embodiment of the present invention. [Figure 9] FIG. 10 is a diagram illustrating a display device according to another embodiment of the present invention. [Figure 10] FIG. 10 is a diagram illustrating a display device according to another embodiment of the present invention. [Figure 11] FIG. 10 is a diagram illustrating a display device according to another embodiment of the present invention. [Figure 12] FIG. 10 is a diagram illustrating a display device according to another embodiment of the present invention. [Figure 13] FIG. 10 is a diagram illustrating a display device according to another embodiment of the present invention. [Figure 14] FIG. 10 is a diagram illustrating a display device according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] The purpose, technical configuration, and operational effects of the present specification will be more clearly understood from the following detailed description with reference to the drawings illustrating examples of the present specification. The examples of the present specification are provided to fully convey the technical ideas of the present specification to those skilled in the art, and the present specification is not limited to the examples described below and may be embodied in other forms.

[0027] Furthermore, parts denoted by the same reference numerals throughout the specification refer to the same components, and in the drawings, the length and thickness of layers or regions may be exaggerated for convenience. Furthermore, when a first component is described as being "on" a second component, this includes not only the case where the first component is located above and in direct contact with the second component, but also the case where a third component is located between the first and second components.

[0028] Here, the terms "first," "second," etc. are used to describe various components and to distinguish one component from another, but the first and second components may be named arbitrarily for the convenience of those skilled in the art without departing from the technical spirit of this specification.

[0029] The terms used in the specification of this specification are used only to describe specific embodiments and are not intended to limit the technical ideas of the specification. For example, elements expressed in the singular include plural elements unless the context clearly dictates that only the singular element is used. Furthermore, in the specification of this specification, terms such as "comprise" or "have" are intended to specify the presence of features, numbers, steps, operations, elements, components, or combinations thereof described in the specification, and should be understood as not precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof.

[0030] Furthermore, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which this specification pertains. Terms, such as those defined in commonly used dictionaries, should be interpreted to have a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense unless expressly defined in the specification of this specification.

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

[0032] 1 to 4, a 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 to be provided to a user. For example, the liquid crystal panel 100 may include an active area AA in which a number of pixel areas are located and a bezel area BZ located outside the active area AA. The bezel area BZ may extend from the active area AA. The bezel area BZ may be disposed to surround a part or all of the active area AA. The liquid crystal panel 100 may include a liquid crystal layer overlapping the pixel areas. For example, the liquid crystal layer of the liquid crystal panel 100 may include an IPS mode liquid crystal or a TN mode liquid crystal. Various signals may be applied to each pixel area via signal lines. For example, liquid crystals located in a portion of the liquid crystal layer overlapping each pixel area may rotate due to a vertical electric field or a horizontal electric field formed in the pixel area via the signal lines. Therefore, the display device according to the embodiment of the present invention can generate images of various colors using 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 source element 210, a backlight light guide plate 220, a backlight reflector plate 230, and a backlight sheet 240.

[0034] The backlight light source elements 210 may supply light to the liquid crystal panel 100 via the backlight light guide plate 220. For example, the backlight light source elements 210 may be located on one side 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 elements 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 material 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 the embodiment of the present invention, light emitted through the lower surface of the backlight light guide plate 220 may be reflected by the backlight reflector 230 toward the liquid crystal panel 100. Therefore, in the display device according to the embodiment of the present invention, the amount of light supplied to the liquid crystal panel 100 by the backlight unit 200 may be increased.

[0036] The backlight sheet 240 may be located between the backlight light guide plate 220 and the liquid crystal panel 100. Light supplied to the liquid crystal panel 100 through the backlight light guide plate 220 may have an overall uniform brightness due to 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 prism members 241p positioned on a first base substrate 241s. The prism members 241p may have various shapes. For example, the cross-sectional shape of the prism members 241p may have a shape in which triangles are repeatedly arranged. The first base substrate 241s may include a transparent material. For example, the first base substrate 241s may include plastic or glass. The prism members 241p may include a transparent material. For example, the prism members 241p may be formed of the same material as the first base substrate 241s. The interface between the first base substrate 241s and the prism members 241p is not recognizable. For example, the prism members 241p may be formed integrally with the first base substrate 241s.

[0038] The diffusion sheet 242 may include diffusion particles 242p dispersed on a second substrate 242s. The second substrate 242s may include a transparent material. For example, the second substrate 242s may include plastic or glass. The second substrate 242s may include the same material as the first substrate 241s. The diffusion particles 242p may have various sizes. Therefore, the display device according to this embodiment may 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 substrate 242s by a transparent adhesive such as resin.

[0039] The backlight unit 200 may include a bottom cover 250 for housing the backlight source elements 210, the backlight light guide plate 220, the backlight reflector 230, and the backlight sheet 240. The bottom cover 250 may include an insulating material. For example, the bottom cover 250 may include plastic, glass, or ceramic. The bottom cover 250 may include a bottom surface and sidewalls protruding from edges of the bottom surface. The backlight reflector 230 may be located between the backlight light guide plate 220 and the bottom surface of the bottom cover 250. The backlight source elements 210, the backlight light guide plate 220, and the backlight sheet 240 may be located within a space formed by the sidewalls of the bottom cover 250. For example, the sidewalls of the bottom cover 250 may partially or entirely surround at least one of the backlight source elements 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 bottom cover 250. For example, the middle frame 260 may include a coupling region extending between the bottom cover 250 and the backlight light guide plate 220. The backlight light source elements 210 may be fixed to the coupling region of the middle frame 260. For example, the backlight light source elements 210 may be attached to the coupling region of the middle frame 260 by an adhesive or a fastening member. The fastening 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 an edge of the backlight sheet 240. For example, the seating region of the middle frame 260 may overlap a part or all of the bezel region BZ of the liquid crystal panel 100. The active area AA of the liquid crystal panel 100 may not overlap the seating area of ​​the middle frame 260. For example, the central area of ​​the backlight sheet 240 may be exposed by the middle frame 260. The seating area of ​​the middle frame 260 may be in direct contact with the backlight sheet 240. Therefore, in the display device according to the embodiment of the present invention, the middle frame 260 can reduce or prevent the movement of the backlight sheet 240.

[0041] The optical module 300 may sense external light through the liquid crystal panel 100 and the backlight unit 200. For example, the optical module 300 may 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 may include a through-hole 230h overlapping the sensing area HA of the liquid crystal panel 100, the backlight sheet 240 may include a sheet hole 240h overlapping the sensing area HA of the liquid crystal panel 100, and the cover bottom 250 may include a cover hole 250h overlapping 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 may not overlap 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 plate 330 , a module sheet 340 , and an optical element 350 .

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

[0043] 2 and 4 to 6, the module light source elements 310 are located on opposite sides of the module light guide plate 320, and the module light guide plate 320 may overlap the sensing area HA of the liquid crystal panel 100. The side of the module light guide plate 320 on which the module light source elements 310 are located may be perpendicular to the top 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 the sensing area HA of the liquid crystal panel 100. For example, the module light source elements 310 may be located on a side that is perpendicular to the top surface of the module light guide plate 320 and the inclined surface 320c. Therefore, in the display device according to an embodiment of the present invention, light emitted from the module light source elements 310 may be supplied to the sensing area HA of the liquid crystal panel 100 via 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 capable of generating and emitting 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 may be mounted on one side end of the module circuit board 311. For example, the module light sources 312 may be turned on / off simultaneously. The module light source 312 may be driven simultaneously with the backlight light source 212. For example, in a display device according to an embodiment of the present invention, the liquid crystal panel 100 may generate an image using light emitted from the backlight light source element 210 and light emitted from the module light source element 310. That is, in a display device according to an embodiment of the present invention, when the liquid crystal panel 100 generates an image, light may be supplied to the sensing area HA of the liquid crystal panel 100 by the module light source element 310. Therefore, in the display device according to the embodiment of the present invention, when the liquid crystal panel 100 generates an image, the light supplied to the sensing area HA can have substantially the same brightness as the light supplied to the active area AA, and therefore, the display device according to the embodiment of the present invention can prevent degradation of image quality due to brightness deviation between the active area AA and the sensing area HA.

[0045] The module reflector 330 may be positioned 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 a metal such as aluminum (Al) or silver (Ag). The module reflector 330 may include the same material as the backlight reflector 230. Therefore, in the display device according to the embodiment of the present invention, the light emitted through the inclined surface 320c of the module light guide plate 320 can be reflected toward the inside of the module light guide plate 320 by the module reflector 330. Therefore, in the display device according to the embodiment of the present invention, the amount of light supplied to the sensing area HA of the liquid crystal panel 100 through the module light guide plate 320 can be increased.

[0046] The module sheet 340 may be disposed on a side of the module light guide plate 320 opposite the inclined surface 320c. The optical element 350 may be disposed on the module sheet 340. For example, in a display device according to an embodiment of the present invention, external light applied to the module light guide plate 320 via the sensing region HA of the liquid crystal panel 100 and the backlight light guide plate 220 may be supplied to the optical element 350 via the module sheet 340. The external light applied via the sensing region HA of the liquid crystal panel 100 may pass through the sheet holes 240h of the backlight sheet 240. Therefore, in a display device according to an embodiment of the present invention, the external light supplied to the optical element 350 may not be refracted and / or diffused by the backlight sheet 240. That is, the display device according to an embodiment of the present invention may sense the external light through the optical element 350 without distortion due to the backlight sheet 240. Therefore, the display device according to an embodiment of the present invention may have improved external light sensing characteristics.

[0047] The module sheet 340 may be located between the module light guide plate 320 and the optical element 350. For example, the module sheet 340 may have a laminated structure including a module adhesive layer 341, a module filter layer 342, and a module heat insulating layer 343. The module adhesive layer 341 may be located near 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 via the module adhesive layer 341. The module heat insulating layer 343 may be located near the optical element 350. Therefore, the display device according to this embodiment may reduce or prevent damage and deformation of the module sheet 340 due to heat generated by operation of the optical element 350. The module filter layer 342 may be located between the module adhesive layer 341 and the module heat insulating layer 343. The module filter layer 342 may reduce or prevent diffusion of visible light among the light traveling through the module light guide plate 320 toward the optical element 350. Here, visible light refers to 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. Therefore, the display device according to the embodiment of the present invention can prevent distortion of light supplied to the optical element 350 due to diffuse reflection and / or specular 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, and 343a corresponding to the camera 351 and second holes 341b and 343b corresponding to the IR sensor 352. The first holes 341a, 342a, and 343a of the module sheet 340 may penetrate the module adhesive layer 341, the module filter layer 342, and the module heat insulating layer 343. For example, the first holes 341a, 342a, and 343a of the module sheet 340 may be composed of the first hole 341a penetrating the module adhesive layer 341, the filter hole 342a penetrating the module filter layer 342, and the first module hole 343a penetrating the module heat insulating layer 343. The second holes 341b and 343b of the module sheet 340 may penetrate the module adhesive layer 341 and the module heat insulating layer 343. The module filter layer 342 may include a filter region 342f overlapping the second holes 341b and 343b of the module sheet 340. For example, the second holes 341b and 343b of the module sheet 340 may be composed of the second hole 341b penetrating the module adhesive layer 341 and the second module hole 343b penetrating the module heat insulating layer 343. Therefore, the display device according to this embodiment of the present invention may provide the camera 351 with external light that has passed through the first holes 341a, 342a, and 343a of the module sheet 340, and provide the IR sensor 352 with external light that has passed through the second holes 341b and 343b of the module sheet 340. That is, the display device according to the 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 can be blocked by the filter region 342f of the module filter layer 342. Therefore, the display device according to the embodiment of the present invention can reduce or prevent degradation of the sensing characteristics of the IR sensor 352 due to visible light.

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

[0050] As a result, a display device according to an embodiment of the present invention includes a liquid crystal panel 100 positioned on an upper surface of a backlight light guide plate 220 and an optical module 300 positioned on a lower surface of the backlight light guide plate 220, the liquid crystal panel 100 including a sensing area HA for sensing external light, and the optical module 300 including a module light guide plate 320 overlapping the sensing area HA, a module light source element 310 positioned on a side perpendicular to an inclined surface 320c of the module light guide plate 320, and an optical element 350 positioned opposite the inclined surface 320c of the module light guide plate 320. Therefore, in the display device according to an embodiment of the present invention, when the liquid crystal panel 100 generates an image, light supplied to the sensing area HA of the liquid crystal panel 100 by the module light source element 310, which is turned on / off simultaneously with the backlight light source element 210, may have the same brightness as light supplied to the active area AA of the liquid crystal panel 100 by the backlight light source element 210. Furthermore, when the liquid crystal panel 100 does not generate an image, the display device according to the embodiment of the present invention can sense external light applied through the sensing area HA of the liquid crystal panel 100, the backlight light guide plate 220, and the module light guide plate 320 using the optical element 350. Therefore, the display device according to the embodiment of the present invention can sense external light without degrading the quality of the image.

[0051] In the display device according to the embodiment of the present invention, the optical element 350 is described as including a camera 351 and an IR sensor 352. However, in the display device according to other embodiments of the present invention, the optical element 350 may include various elements. For example, in the display device according to other embodiments of the present invention, the optical element 350 may include one of the camera 351 and the IR sensor 352. Furthermore, in the display device according to other embodiments 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 other embodiments 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 other embodiments of the present invention can improve the flexibility in the configuration of the optical element 350.

[0052] In the display device according to the embodiment of the present invention, each module light source 312 is described as 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 may be determined depending on the brightness of light supplied to the active area AA of the liquid crystal panel 100 by the backlight light source 212. In addition, in the display device according to another embodiment of the present invention, the type and number of each module light source 312 may be determined depending on 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 the other embodiment of the present invention, when the liquid crystal panel 100 generates an image, the type and number of each module light source 312 may be adjusted so that the brightness of light supplied to the sensing area HA of the liquid crystal panel 100 is substantially the same as the brightness of the light supplied to the active area AA of the liquid crystal panel 100. Therefore, the display device according to the other embodiment of the present invention may effectively prevent degradation of image quality due to brightness deviation between the active area AA and the sensing area HA of the liquid crystal panel 100.

[0053] In the display device according to another embodiment of the present invention, the module heat insulating layer 343 may include a material capable of absorbing light. For example, the module heat insulating layer 343 may include a black dye such as carbon black. The module heat insulating layer 343 may have a multi-layer structure. For example, the module heat insulating layer 343 may have a double-layer structure of a heat insulating layer and an absorbing layer. Therefore, in the display device according to another embodiment of the present invention, the module heat insulating layer 343 may block light traveling through a portion of the module sheet 340 that does not overlap with the optical element 350. Therefore, the display device according to another embodiment of the present invention may have improved external light sensing characteristics.

[0054] In the display device according to the embodiment of the present invention, the optical element 350 is described as being located near the center of the backlight unit 200. However, in the display device according to the other embodiment of the present invention, the optical element 350 may be located at various positions. For example, as shown in FIG. 7 , in the display device according to the other embodiment of the present invention, the optical element 350 may be located on a side of the module light guide plate 320 facing outward from the backlight unit 200. The inclined surface of the module light guide plate 320 may be located near the center of the backlight unit 200. Therefore, the display device according to the other embodiment of the present invention can have greater flexibility in the position of the optical element 350.

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

[0056] In the display device according to the embodiment of the present invention, the prism member 241p is described as including the same material as the first base substrate 241s. However, in the display device according to other embodiments of the present invention, the first base substrate 241s may include a different material from 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 other embodiments of the present invention can improve the flexibility 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 substrate substrate 241s and the second substrate substrate 242s may include a region located outside the corresponding optical member, for example, the prism member 241p or the diffusing particles 242p. For example, as shown in FIG. 9, in a display device according to another embodiment of the present invention, the first substrate substrate 241s and the second substrate substrate 242s may extend inward of the sheet hole 240h. Each of the first substrate substrate 241s and the second substrate substrate 242s may include a region overlapping with a sensing region of the liquid crystal panel. The sheet hole 240h may be a region where the prism member 241p and the diffusing particles 242p are not formed. That is, in a display device according to another embodiment of the present invention, the process of forming a hole in the first substrate substrate 241s and the process of forming a hole in the second substrate substrate 242s may be omitted. Therefore, the display device according to another embodiment of the present invention may improve the efficiency of a process for forming a backlight sheet 240.

[0058] 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, a portion of the prism member 241p overlapping a sensing region of the liquid crystal panel is covered by a first index matching member 241m, and a portion of the diffusion particles 242p overlapping a sensing region of the liquid crystal panel is covered by a second index matching member 242m. The first index matching member 241m may include a material capable of offsetting refraction by the prism member 241p. The second index matching member 242m may include a material capable of offsetting 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 refraction by the prism member 241p and the diffusion particles 242p may be formed by the first index matching member 241m and the second index matching member 242m. That is, the display device according to another embodiment of the present invention may omit the process of removing the prism member 241p formed on a portion of the first base substrate 241s overlapping the sensing region of the liquid crystal panel and the process of removing the diffusion particles 242p formed on a portion of the second base substrate 242s overlapping the sensing region of the liquid crystal panel, thereby effectively improving process efficiency.

[0059] In the display device according to an embodiment of the present invention, the module circuit board 311 is positioned parallel to the upper surface of the module light guide plate 320 facing the backlight light guide plate 220, and the module light sources 312 are mounted at the edge of the module circuit board 311. However, in a display device according to another embodiment of the present invention, the module light sources 312 may be positioned near the center of the module light guide plate 320. For example, as shown in FIG. 11 , in a display device according to another embodiment of the present invention, a step 320d may be formed on the upper end of the side of the module light guide plate 320 facing each module light source 312. The module circuit board 311 may extend along the step 320d of the module light guide plate 320. Therefore, the display device according to another embodiment of the present invention may prevent a decrease in efficiency due to the position of the module light source 312. Furthermore, the display device according to another embodiment of the present invention may prevent brightness deviations in the active area AA and the sensing area HA due to a decrease in efficiency of the module light source 312.

[0060] In display devices according to other embodiments of the present invention, the module light guide plate 320 may have various shapes to accommodate the movement of the module light source 312. For example, in display devices according to other embodiments of the present invention, a portion of the module light guide plate 320 overlapping the module light source element 310 may be recessed to form a groove in the module light guide plate 320, and the module light source element 310 may be inserted into the groove in the module light guide plate 320. Also, as shown in FIG. 12 , in display devices according to other embodiments of the present invention, a side 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 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 devices according to other embodiments of the present invention may 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 decrease 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 brightness deviation between the active area AA and the sensing area HA.

[0061] In the display device according to an embodiment of the present invention, the module light source element 310 and the optical element 350 are described as being located outside the sensing area HA. ​​However, as shown in FIG. 13 , in a 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-transmitting surface 320sr inclined relative 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, light emitted from the module light source element 310 can be reflected toward the sensing area HA of the liquid crystal panel 100 by the semi-transmitting surface 320sr of the module light guide plate 320. Furthermore, when the liquid crystal panel 100 does not generate an image, the display device according to another embodiment of the present invention may supply external light applied via the sensing region HA of the liquid crystal panel 100 and the backlight light guide plate 220 to the optical element 350 through the semi-transmitting surface 320sr of the module light guide plate 320. That is, the display device according to another embodiment of the present invention may prevent degradation of image quality due to the sensing region HA and may effectively improve the degree of freedom for the position of the optical element 350.

[0062] In the display device according to an embodiment of the present invention, the module light guide plate 320 is described as having an inclined surface 320c. However, in display devices according to other embodiments 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 , the display device according to another embodiment of the present invention may have the module light guide plate 320 in a plate shape having a certain curvature. For example, the display device according to another embodiment of the present invention may reflect external light applied through the sensing region HA of the liquid crystal panel 100 and the backlight light guide plate 220 toward the optical element 350 due to the refractive index difference at the curved surface of the module light guide plate 320. That is, the display device according to another embodiment of the present invention may omit the module reflector. Therefore, the display device according to another embodiment of the present invention may have greater flexibility in 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. [Explanation of symbols]

[0063] 100 LCD panels 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 Elements

Claims

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

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

3. The display device of claim 1 , wherein the second light source elements are located on two opposing side surfaces of the second light guide plate that are perpendicular to the top surface.

4. the backlight unit includes a cover bottom that accommodates the first light guide plate and the first light source element; The display device of claim 1 , wherein the cover bottom includes a cover hole overlapping the sensing area of ​​the liquid crystal panel.

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

6. The display device of claim 5 , wherein the optical module further comprises a module reflector positioned on the inclined surface of the second light guide plate.

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

8. The display device of claim 7 , wherein the module sheet includes a module adhesive layer located near the second light guide plate and a module heat-insulating layer located near the optical element.

9. The display device of claim 8 , wherein the module sheet further comprises a module filter layer located between the module adhesive layer and the module heat insulating 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; the first hole penetrates the module adhesive layer, the module heat insulating layer, and the module filter layer; the second hole penetrates the module adhesive layer and the module heat insulating layer; The display device of claim 9 , wherein the module filter layer includes an area corresponding to the second hole.

11. the backlight unit includes a backlight sheet disposed 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 overlapping the sensing area 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 of claim 1 , wherein the second light source element and the optical element are located on different surfaces of the second light guide plate.

14. 2. The display device of claim 1, wherein when the liquid crystal panel generates an image, the light provided to the sensing area by the second light source element has the same brightness as the light provided to the active area of ​​the liquid crystal panel by the first light source element.

15. a backlight unit including a first light source element positioned on one side of a first light guide plate and a cover bottom accommodating 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 area; a light source module including: a second light guide plate having 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 overlapping the sensing area of ​​the liquid crystal panel; the second light guide plate of the light source module overlaps with the sensing area of ​​the liquid crystal panel; The optical element is located on a path of light that has passed through the first light guide plate and the second light guide plate.

16. The display device of claim 15, further comprising 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 of 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 disposed between the cover bottom and the first light guide plate; The display device of claim 15 , wherein the reflector includes a through-hole overlapping the sensing area of ​​the liquid crystal panel.

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

20. the optical element is located on a lower surface of the second light guide plate opposite to the upper surface, The display device of claim 15, wherein a semi-transmissive surface is positioned within the second light guide plate, the semi-transmissive surface being inclined relative to the upper and lower surfaces of the second light guide plate.

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