Display device which has a backlighting unit and a liquid crystal panel

Abstract

Display device (DP) comprising: a backlight unit (200) comprising a second light guide plate (222) arranged on a first light guide plate (221) and a light source element (210), a liquid crystal panel (100) on the second light guide plate (222) of the backlight unit (200), a first viewing angle control unit (410) arranged between the first light guide plate (221) and the second light guide plate (222) of the backlight unit (200), wherein the first viewing angle control unit (410) comprises first light-blocking patterns (413), and a retaining element (500) arranged between an edge of the first light guide plate (221) and an edge of the first viewing angle control unit (410), wherein the light source element (210) comprises a first light source (211) on one side of the first light guide plate (221).a second light source (212) on one side of the second light guide plate (222) and a light source circuit plate (213) in which the first light source (211) and the second light source (212) are mounted, and wherein the retaining element (500) is in contact with a surface of the light source circuit plate (213) between the first light source (211) and the second light source (212).

Description

Cross-reference to related registration

[0001] This application claims the benefit of Korean patent application No. 10-2020-0186540, which was filed on December 29, 2020. Background: Area of ​​Revelation

[0002] The present disclosure relates to a display device in which a liquid crystal panel is arranged on a backlight unit. Background description

[0003] Generally, a display device is provided to create an image. For example, the display device may include a liquid crystal panel mounted on a backlight unit. The backlight unit can provide light. The liquid crystal panel can create the image using the light provided by the backlight unit.

[0004] The display device can be used in various locations. For example, it can be installed in front of a passenger seat in a vehicle. The image displayed by the device can distract the eyes of people around the user, such as the driver. Therefore, the viewing angle of the display device can be selectively limited to prevent accidents caused by eye strain. For example, the display device can include a backlight unit with a second light guide plate mounted on top of a first light guide plate, and a viewing angle control unit positioned between the first and second light guide plates of the backlight unit.

[0005] The display device may include a retaining element to hold the viewing angle control unit and the second light guide plate. The retaining element may be coupled to a cover base that houses a light source element, the first light guide plate, the second light guide plate, and the viewing angle control unit. For example, at least one coupling hole may be formed in the cover base, and part of the retaining element may be attached to the coupling hole of the cover base by means of a press fit. However, particles may be generated in the display device during the coupling process of the retaining element with the cover base. These particles may block the light emitted by the backlight unit. Therefore, the particles may be perceived by the user as a dark spot in the display device. overview

[0006] Accordingly, the present disclosure relates to a display device which essentially eliminates one or more problems arising from limitations and disadvantages of the related technology.

[0007] More precisely, one objective of the present disclosure is to provide a display device capable of reducing or preventing the deterioration of image quality due to the coupling process of the holding element.

[0008] One objective of the present disclosure is also to provide a display device that is capable of reducing or preventing the particles generated during the coupling process of the holding element from interfering with the realization of the image.

[0009] Additional advantages and features of the disclosure are partly set forth in the following description and partly become apparent to a person skilled in the art as a result of examining the following or can be learned from practical experience with the disclosure. The features and other advantages of the disclosure can be realized and achieved by means of the structure particularly highlighted in the written description and the claims thereto, as well as in the accompanying drawings.

[0010] To achieve these and other advantages, and in accordance with the purpose of the disclosure as embodied and broadly described herein, a display device according to claim 1 and a display device according to claim 9 are provided. Preferred embodiments are described in the dependent claims. In accordance with one aspect of the present disclosure, a display device is provided that includes a backlighting unit. The backlighting unit comprises a first light guide plate, a second light guide plate, and a light source element. The light source element comprises a light source circuit plate in which a first light source, arranged on one side of the first light guide plate, and a second light source, arranged on one side of the second light guide plate, are mounted.A liquid crystal panel is arranged on the second light guide plate of the backlight unit. A first viewing angle control unit is arranged between the first and second light guide plates of the backlight unit. The first viewing angle control unit has first light-blocking patterns. A retaining element is arranged between an edge of the first light guide plate and an edge of the first viewing angle control unit. The retaining element is in contact with a surface of the light source circuit board between the first and second light sources.

[0011] The retaining element may be made of metal.

[0012] A lower surface of the first viewing angle control unit in the direction of the first light guide plate has an area that is in contact with the retaining element.

[0013] An optical film can be positioned between the first light guide plate and the first viewing angle control unit. An upper surface of the optical film, facing the first viewing angle control unit, can have an area that is in contact with the retaining element.

[0014] The light source circuit board can have a first light source area, a second light source area, and an intermediate area. The first light source can be mounted in the first light source area. The second light source can be mounted in the second light source area. The intermediate area can be located between the first and second light source areas. The retaining element can be in contact with the intermediate area of ​​the light source circuit board. The second light source area can be positioned at a distance from the intermediate area.

[0015] The intermediate area can be in contact with the first light source area.

[0016] The light source circuit board may further have a connection area that is in contact with one side of the first light source area and one side of the second light source area.

[0017] A second viewing angle control unit can be positioned between the backlight unit and the liquid crystal panel. This second viewing angle control unit can incorporate second light-blocking patterns. These second light-blocking patterns can extend in a direction perpendicular to the first light-blocking patterns.

[0018] In another aspect, a display device is provided which has a first light guide plate. At least one first light source is arranged on one side of the first light guide plate. A viewing angle control unit is arranged on the first light guide plate. The viewing angle control unit has light-blocking patterns. A second light guide plate is arranged on the viewing angle control unit. The second light guide plate overlaps the first light guide plate. At least one second light source is arranged on one side of the second light guide plate. A liquid crystal panel is arranged on the second light guide plate. A light source circuit board has an intermediate area between a first light source area, in which the at least one first light source is mounted, and a second light source area, in which the at least one second light source is mounted.The intermediate section of the light source circuit board is in contact with a retaining element. The retaining element extends between an edge of the first light guide board and an edge of the viewing angle control unit.

[0019] The first light guide plate, the at least one first light source, the viewing angle control unit, the second light guide plate, the at least one second light source, the light source circuit board, and the retaining element can be housed in a cover base. The cover base can have a side wall that is located on one side of the first light guide plate and on one side of the second light guide plate. The light source circuit board can be attached to the side wall of the cover base by means of a substrate adhesive layer.

[0020] The intermediate section of the light source circuit board can have at least one coupling hole. The retaining element can have at least one protruding section that is attached to the at least one coupling hole of the light source circuit board.

[0021] An adhesive layer can be arranged between the light source circuit board and the retaining element. The adhesive layer can have at least one through hole through which the protruding section of the retaining element passes.

[0022] The retaining element may contain an insulating material.

[0023] The retaining element can have a rod shape that extends along an edge of the viewing angle control unit.

[0024] An air gap can be arranged between the first light guide plate and the viewing angle control unit. The air gap can be positioned side by side with the mounting element. List of characters

[0025] The accompanying drawings, which are included to provide a further understanding of the revelation and which are incorporated into and form part of this application, illustrate one or more aspects of the revelation and, together with the description, serve to explain the principle of revelation.

[0026] In the drawings: is Fig. 1 a view showing a location where a display device is used in accordance with any aspect of the present disclosure, is Fig. 2 a schematic view showing the display device according to the aspect of the present disclosure, is Fig. 3 a view showing a coupling state of a backlight unit, a first viewing angle control unit and a holding element of the display device according to the aspect of the present disclosure, is Fig. 4 a view showing a separation state of a light source element and a holding element of the display device according to the aspect of the present disclosure, is Fig. 5 a view showing a first viewing angle control unit of the display device according to the aspect of the present disclosure, is Fig. 6 a view showing a second viewing angle control unit of the display device according to the aspect of the present disclosure, are Fig. 7A and Fig. 7B Views showing a direction of propagation of light emitted by the backlighting unit according to a change in a viewing angle in the display device according to the aspect of the present disclosure, are Fig. 8, Fig. 9A-9C, Fig. 10 and Fig. 11 views showing a display device according to another aspect of the present disclosure. Detailed description

[0027] Details relating to the above-mentioned properties, technical configurations, and operational effects of the aspects of this disclosure will be clearly understood through the following detailed description with reference to the drawings, which illustrate some aspects of this disclosure. The aspects of this disclosure are provided here to allow the technical idea(s) of this disclosure to be satisfactorily conveyed to the person skilled in the art; therefore, this disclosure may be embodied in other forms and is not limited to the aspects described below.

[0028] Furthermore, identical or extremely similar elements may be designated with the same reference symbols throughout the description, and in the drawings, the lengths and thicknesses of layers and areas may be exaggerated for the sake of simplicity. It should be understood that if a first element is described as being "on" a second element, a third element may be positioned between the first and second elements, even though the first element may be positioned on top of the second element in such a way that it is in contact with the second element.

[0029] Here, terms such as "first" and "second" can be used to distinguish one element from another. However, the first and second elements can be named arbitrarily according to the conventions of those skilled in the art, without deviating from the technical content of the present disclosure.

[0030] The terms used in the description of this revelation are employed solely to describe certain aspects and are not intended to limit the scope of this revelation. For example, an element described in the singular is intended to have multiple elements unless the context clearly indicates otherwise. Furthermore, in the description of this revelation, the terms "have" and "contain" are to be understood as specifying the presence of the aforementioned properties, integers, steps, processes, elements, components, and / or combinations thereof, but do not preclude the presence or addition of one or more other properties, integers, steps, processes, elements, components, and / or combinations.

[0031] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as they are generally understood by a person skilled in the art in the field to which the exemplary aspects belong. Furthermore, terms such as those defined in generally used dictionaries are to be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and are not to be interpreted in an idealized or overly formal sense, unless expressly defined as such herein.

[0032] Fig. Figure 1 is a view showing a location where a display device DP is used according to one aspect of the present disclosure.

[0033] Referring to Fig. 1. The display device DP, according to the aspect of this disclosure, can be installed in front of a passenger seat PS of a vehicle. Therefore, the display device DP, according to the aspect of this disclosure, can prevent accidents caused by the distraction of the driver sitting in the driver's seat DS by limiting the viewing angle while the vehicle is in motion. For example, the display device DP, according to the aspect of this disclosure, can comprise a liquid crystal panel 100, a backlight unit 200, and a first viewing angle control unit 410, as shown in Fig. 2 to Fig. 6 shown.

[0034] The liquid crystal panel 100 can realize an image that is provided to a user. For example, the liquid crystal panel 100 can have a liquid crystal layer between two substrates. The transmittance of the liquid crystal layer can be changed according to an electric field generated between a pixel electrode and a common electrode. For example, the liquid crystal layer can have a liquid crystal of an IPS (In-Plane Switching) mode, an ECB (Electronically Controlled Birefringence) mode, or a TN (Twisted Nematic) mode. A linear polarizer 310 and 320 can be arranged on an outer surface of the liquid crystal panel 100. For example, the liquid crystal panel 100 can be arranged between a first linear polarizer 310 and a second linear polarizer 320.The transmission axis of the second linear polarizer 320 can be perpendicular to the transmission axis of the first linear polarizer 310.

[0035] The backlight unit 200 can provide light to the liquid crystal panel 100. For example, the backlight unit 200 can have a light source element 210, a first light guide plate 221, and a second light guide plate 222. The second light guide plate 222 can be arranged on the first light guide plate 221. The light source element 210 can emit light to the first light guide plate 221 and / or to the second light guide plate 222. For example, the light source element 210 can have a first light source 211 arranged on one side of the first light guide plate 221 and a second light source 212 arranged on one side of the second light guide plate 222. The second light source 212 can be mounted on the same light source circuit board 213 as the first light source 211.For example, the light source circuit board 213 of the light source element 210 can extend from the side of the first light guide board 221 to the side of the second light guide board 222. The light source circuit board 213 can have an intermediate area MA located between a first light source area LA1, in which the first light source 211 is mounted, and a second light source area LA2, in which the second light source 212 is mounted.

[0036] The first light guide plate 221 and the second light guide plate 222 can operate as a single area light source. For example, the light incident on the first light guide plate 221 from the first light source 211 can be emitted through an entire upper surface of the first light guide plate 221 to the second light guide plate 222, and the light incident on the second light guide plate 222 from the second light source 212 can be emitted through an entire upper surface of the second light guide plate 222 to the liquid crystal panel 100. The light emitted from the upper surface of the first light guide plate 221 can be supplied to the liquid crystal panel 100 by passing through the second light guide plate 222. For example, the second light guide plate 222 can overlap the first light guide plate 221. The liquid crystal panel 100 can be arranged on the upper surface of the second light guide plate 222.

[0037] The backlight unit 200 can have a first optical film 230a between the first light guide plate 221 and the second light guide plate 222, and a second optical film 230b on the upper surface of the second light guide plate 222. The light emitted through the upper surface of the first light guide plate 221 can acquire uniform properties by passing through the first optical film 230a. For example, the first optical film 230a can have a stacked structure consisting of a first diffusion film 231a and a first prism film 232a. The light emitted through the upper surface 222 can acquire uniform properties by passing through the second optical film 230b. The second optical film 230b can have a stacked structure identical to that of the first optical film 230a. For example, the second optical film 230b can have a stacked structure consisting of a second diffusion film 231b and a second prism film 232b.

[0038] The backlight unit 200 can have a reflective plate 240 arranged on a lower surface of the first light guide plate 221, the lower surface of the first light guide plate 221 being opposite the upper surface of the first light guide plate 221, which is opposite the second light guide plate 222. The reflective plate 240 can be made of a material with a high reflectivity. For example, the reflective plate 240 can be made of a metal, such as aluminum (Al) or silver (Ag). The light emitted by the lower surface of the first light guide plate 221 can be reflected by means of the reflective plate 240 towards the second light guide plate 222. Therefore, in the display device DP according to the aspect of this disclosure, the loss of the light emitted by the light source element 210 can be reduced or minimized.

[0039] The first viewing angle control unit 410 can be arranged between the first light guide plate 221 and the second light guide plate 222. For example, the first viewing angle control unit 410 can be arranged between the first optical film 230a and the second light guide plate 222. The first viewing angle control unit 410 can have first light-blocking patterns 413 arranged between a first lower control substrate 411 and a first upper control substrate 412. The first light-blocking patterns 413 can have a material capable of blocking light. For example, the first light-blocking patterns 413 can have a black dye, such as carbon black.

[0040] The first viewing angle control unit 410 can limit a viewing angle in a first direction X. For example, the first light-blocking patterns 413 can extend in a second direction Z perpendicular to the first direction X. Here, the first direction X can be a left-to-right direction (or a horizontal direction) of the user, and the second direction Z can be an up-to-down direction (or a vertical direction) of the user. For example, in the vehicle in which the display device DP according to the aspect of the present disclosure is installed in front of the passenger seat PS, the image realized by the display device DP according to the aspect of the present disclosure cannot be recognized by the driver sitting in the driver's seat DS by means of the first viewing angle control unit 410.Therefore, in the display device DP, according to the aspect of the present disclosure, accidents caused by the distraction of persons around the user, such as the driver, can be reduced or prevented by means of the first viewing angle control unit 410.

[0041] The first viewing angle control unit 410 can have a first control insulating layer 414 surrounding the first light-blocking patterns 413. The first control insulating layer 414 can be made of an insulating material. The first control insulating layer 414 can be made of a transparent material. For example, the light emitted by the upper surface of the first light guide plate 221 can pass through the first control insulating layer 414 between the first light-blocking patterns 413. A space between the first lower control substrate 411 and the first upper control substrate 412 can be completely filled by the first light-blocking patterns 413 and the first control insulating layer 414. Therefore, in the display device DP according to the aspect of the present disclosure, damage and deformation of the first light-blocking patterns 413 due to external influence can be reduced or prevented.

[0042] A second viewing angle control unit 420 can be arranged between the backlight unit 200 and the liquid crystal panel 100. For example, the second viewing angle control unit 420 can be arranged between the second light guide plate 222 of the backlight unit 200 and the first linear polarizer 310. The second viewing angle control unit 420 can have a stacked structure identical to the first viewing angle control unit 410. For example, the second viewing angle control unit 420 can have second light-blocking patterns 423 arranged between a second lower control substrate 421 and a second upper control substrate 422. The second light-blocking patterns 423 can comprise a material capable of blocking light. For example, the second light-blocking patterns 423 can comprise a black dye, such as carbon black.The second light-blocking patterns 423 can have the same material as the first light-blocking patterns 413.

[0043] The second viewing angle control unit 420 can limit a viewing angle in the second direction Z. For example, the second light-blocking patterns 423 can extend parallel to each other in the first direction X. Each of the second light-blocking patterns 423 can vertically intersect the first light-blocking patterns 413 (in other words, the directions in which the first and second light-blocking patterns 413, 423 extend can be perpendicular to each other). In the vehicle in which the display device DP is installed in front of the passenger seat PS according to the aspect of the present disclosure, the reflection of the image from the windshield FW can be reduced or prevented by means of the second viewing angle control unit 420.Therefore, in the display device DP, according to the aspect of the present disclosure, accidents caused by the distraction of persons around the user can be effectively reduced or prevented by means of the second viewing angle control unit 420.

[0044] The second viewing angle control unit 420 can have a second control insulating layer 424 surrounding the second light-blocking patterns 423. The second control insulating layer 424 can be made of an insulating material. The second control insulating layer 424 can be made of a transparent material. For example, the second control insulating layer 424 can be made of the same material as the first control insulating layer 414. The light emitted by the upper surface of the second light guide plate 222 can pass through the second control insulating layer 424 between the second light-blocking patterns 423. A space between the second lower control substrate 421 and the second upper control substrate 422 can be completely filled by the second light-blocking patterns 423 and the second control insulating layer 424.Therefore, in the display device DP, according to the aspect of the present disclosure, damage and deformation of the second light-blocking pattern 423 due to external influence can be reduced or prevented.

[0045] The first viewing angle control unit 410 and the second light guide plate 221 can be held by a retaining element 500. For example, the retaining element 500 can be positioned between an edge of the first light guide plate 221 and an edge of the first viewing angle control unit 410. For example, a lower surface of the first viewing angle control unit 410, facing the first light guide plate 221, can have a region that is in contact with the retaining element 500. The retaining element 500 can be rod-shaped and extend along the edge of the first viewing angle control unit 410. The first viewing angle control unit 410 can be positioned at a distance from the first optical film 230a by means of the retaining element 500. For example, an air gap AG can be positioned between the first optical film 230a and the first viewing angle control unit 410.The air gap AG can be arranged side by side with the retaining element 500. Therefore, in the display device DP, an optical path for the first optical film 230a can be sufficiently ensured according to the aspect of the present disclosure.

[0046] The retaining element 500 can press against an edge of the first optical film 230a. For example, an upper surface of the first optical film 230a facing the first viewing angle control unit 410 can have a region that is in contact with the retaining element 500. The air gap AG arranged between the first optical film 230a and the first viewing angle control unit 410 can have a vertical distance equal to the thickness of the retaining element 500. Therefore, in the display device DP according to the aspect of this disclosure, the mobility of the first optical film 230a can be reduced or prevented by means of the retaining element 500.

[0047] The retaining element 500 can be coupled to the light source element 210. For example, the retaining element 500 can be attached to a surface of the light source circuit board 213 between the first light source 211 and the second light source 212 using surface mount technology (SMT). The retaining element 500 can be made of metal. For example, the retaining element 500 can be made of metal. The retaining element 500 can be in contact with the intermediate area MA of the light source circuit board 213. Therefore, in the display device DP according to the aspect of this disclosure, particles generated during a coupling process of the retaining element 500 can be minimized.

[0048] The backlight unit 200 can have a cover base 250 that houses the light source element 210, the first light guide plate 221, the second light guide plate 222, the first optical film 230a, the second optical film 230b, the reflective plate 240, the first viewing angle control unit 410, and the retaining element 500. For example, the cover base 250 can have a sub-section 251 that holds the reflective plate 240 and a side wall 252 that extends from an edge of the sub-section 251 toward the liquid crystal panel 100. The side wall 252 of the cover base 250 can be located on one side of the first light guide plate 221 and on one side of the second light guide plate 222. The light source circuit board 213 of the light source element 210 can be attached to the cover base 250.For example, the light source circuit board 213 can be attached to the side wall 252 of the cover base 250 by means of a substrate adhesive layer 260. Therefore, in the display device DP according to the aspect of the present disclosure, the generation of particles during a coupling process of the light source element 210 can be reduced or prevented.

[0049] An edge of the second optical film 230b can be pressed against a guide plate 270. For example, the second viewing angle control unit 420 and the liquid crystal panel 100 can be stacked on the guide plate 270. The guide plate 270 can be coupled to the cover base 250. For example, the guide plate 270 can have a flat plate section 271 that has an area in contact with an edge of the second optical film 230b, and a coupling section 272 that extends along the side wall 252 of the cover base 250.

[0050] Fig. Figure 7A is a view showing a direction of propagation of the light emitted by the backlight unit 200 when the viewing angle is limited, so that the image realized by the display device DP according to the aspect of the present disclosure is not recognized by the persons around the user.

[0051] With reference to Fig. 1 to Fig. 6 and Fig. 7A in the display device DP according to the aspect of the present disclosure, the light emitted by the first light source 211 can fall on the first light guide plate 221, and the second light source 212 cannot emit any light.

[0052] Therefore, in the display device DP according to the aspect of the present disclosure, the light L1, in which the viewing angle in the first direction X is limited by the first viewing angle control unit 410, can be provided to the second viewing angle control unit 420 by passing through the second light guide plate 222. Therefore, in the display device DP according to the aspect of the present disclosure, the viewing angle in the first direction X can be limited by the first viewing angle control unit 410, and the image generated by the light, in which the viewing angle in the second direction Z perpendicular to the first direction X is limited by the second viewing angle control unit 420, can be provided to the user. That is to say, in the display device DP according to the aspect of the present disclosure, the realized image cannot be perceived by people around the user, such as the driver.

[0053] Fig. Figure 7B is a view showing a direction of propagation of the light emitted by the backlighting unit 200 when the image realized by the display device DP according to the aspect of the present disclosure is shared with the persons around the user.

[0054] With reference to Fig. 1 to Fig. 6 and Fig. 7B In the display device DP according to the aspect of the present disclosure, the light emitted by the first light source 211 can fall onto the first light guide plate 221, and the light emitted by the second light source 212 can fall onto the second light guide plate 222. Therefore, in the display device DP according to the aspect of the present disclosure, the light L1, in which the viewing angle in the first direction X is limited by means of the first viewing angle control unit 410, can be provided to the second viewing angle control unit 420 together with the light L2, in which the viewing angle in the first direction X is not limited, by means of the second light guide plate 222. That is to say, in the display device DP according to the aspect of the present disclosure, the viewing angle can only be limited in the second direction Z perpendicular to the first direction X by means of the second viewing angle control unit 420.Therefore, in the display device DP, according to the aspect of the present disclosure, the realized image can be shared with the persons who are adjacent to the user in the first direction X, such as the driver sitting in the driver's seat DS.

[0055] Accordingly, the display device DP, according to the aspect of this disclosure, can comprise the backlight unit 200, which has the light source element 210, the first light guide plate 221 and the second light guide plate 222, the liquid crystal panel 100 on the second light guide plate 222 of the backlight unit 200, and the first viewing angle control unit 410 between the first light guide plate 221 and the second light guide plate 222 of the backlight unit 200, wherein the retaining element 500, which holds the first viewing angle control unit 410 and the second light guide plate 222, can be in contact with the surface of the light source circuit plate 213 of the light source element 210. Therefore, according to the aspect of this disclosure, the display device DP can reduce or minimize the generation of particles during the coupling process of the retaining element 500.And in the display device DP according to the aspect of this disclosure, the retaining element 500 can be housed in the cover base 250 in the state in which it is coupled to the light source circuit board 213. That is to say, in the display device DP according to the aspect of this disclosure, particles generated during the coupling process of the retaining element 500 cannot impair the light emitted by the backlight unit 200. Therefore, in the display device DP according to the aspect of this disclosure, the viewing angle can be selectively limited by controlling the first light source 211, which is arranged on the side of the first light guide board 221, and the second light source 212, which is arranged on the side of the second light guide board 222, and the deterioration of image quality due to the coupling process of the retaining element 500 can be reduced or prevented.

[0056] In the display device DP according to one aspect of the present disclosure, the light source circuit board 213 has the form of a single plate. However, in a display device according to another aspect of the present disclosure, the light source circuit board 213 can be of various forms. For example, in the display device according to another aspect of the present disclosure, the light source circuit board 213 can have a first gap G1 arranged between the first light source 211, which is mounted in the first light source region LA1, and the intermediate region MA, and a second gap G2 arranged between the second light source 212, which is mounted in the second light source region LA2, and the intermediate region MA, as shown in Fig. Figure 8 shows. Therefore, in the display device according to another aspect of the present disclosure, particles generated during the process of attaching the retaining element 500 to the intermediate area MA of the light source circuit board 213 cannot be moved towards the first light source 211 and the second light source 212. That is, in the display device according to another aspect of the present disclosure, damage to the first light source 211 and the second light source 212 due to particles generated during the coupling process of the retaining element 500 can be reduced or prevented. And in the display device according to another aspect of the present disclosure, particles generated during the coupling process of the retaining element 500 can be easily removed using the first gap Gl and the second gap G2.Therefore, according to another aspect of the present disclosure, it is possible with the display device to effectively prevent particles generated during the coupling process of the holding element 500 from being perceived by the user as a dark spot.

[0057] In the display device DP according to one aspect of the present disclosure, the light source circuit board 213 has a shape that extends to the side of the second light guide board 222 from the side of the first light guide board 221. However, a display device according to another aspect of the present disclosure may have the light source circuit board 213 having a strip shape. For example, in the display device according to another aspect of the present disclosure, the light source circuit board 213 may have a connecting area CA arranged between one side of the first light source area LA1 and one side of the second light source area LA2, and the connecting area CA of the light source circuit board 213, which has a strip shape, may be folded twice so that the second light source area LA2 may be arranged on top of the first light source area LA1, as shown in Fig. 9A to Fig. Figure 9C shows that the intermediate area MA, where the retaining element 500 contacts the light source plate 213, can be in contact with the first light source area LA1. For example, the second light source area LA2, which is arranged on top of the first light source area LA1 by folding the connecting area CA, can be positioned at a distance from the intermediate area MA. Therefore, in the display device according to another aspect of this disclosure, the degree of freedom for the shape of the light source circuit board 213 can be improved.

[0058] In the display device DP according to one aspect of the present disclosure, the retaining element 500 is attached to the intermediate area MA of the light source circuit board 213 using surface mounting (SMT) technology. However, in a display device according to another aspect of the present disclosure, the retaining element 500 can be coupled to the light source circuit board 213 in various ways. For example, in the display device according to another aspect of the present disclosure, the intermediate area MA of the light source circuit board 213, in which the first light source 211 and the second light source 212 are mounted, can have at least one coupling hole 213h, and the retaining element 500 can have at least one projecting section 500p that is attached to the coupling hole 213h, as shown in Fig. 10 and Fig.Figure 11 shows that, for example, the retaining element 500 can be made of an insulating material that is easy to process, such as plastic. Therefore, in the display device according to another aspect of the present disclosure, the degree of freedom for the material of the retaining element 500 can be improved.

[0059] An element adhesive layer 510 can be arranged between the intermediate area MA of the light source circuit board 213 and the retaining element 500. The element adhesive layer 510 can comprise an adhesive material. For example, the retaining element 500 can be coupled to the light source circuit board 213 by means of the preceding section 500p and the element adhesive layer 510. The element adhesive layer 510 can surround the preceding section 500p of the retaining element 500. For example, the element adhesive layer 510 can have at least one penetrating hole 510h located in a region corresponding to the coupling hole 213h of the light source circuit board 213. The preceding section 500p of the retaining element 500 can pass through the penetrating hole 510h.Therefore, in the display device according to another aspect of the present disclosure, particles generated during the coupling process of the retaining element 500 can be attached to the element adhesive layer 510. That is, in the display device according to another aspect of the present disclosure, particles generated during the coupling process of the retaining element 500 cannot be moved towards the first light guide plate 221 and / or the second light guide plate 222. Therefore, in the display device according to another aspect of the present disclosure, the deterioration of image quality due to particles generated during the coupling process of the retaining element 500 can be reduced or prevented.

[0060] As a result, the display device according to the aspects of this disclosure can comprise the backlight unit in which the second light guide plate is arranged on the first light guide plate, the viewing angle control unit between the first light guide plate and the second light guide plate of the backlight unit, and the retaining element that holds the viewing angle control unit and the second light guide plate, wherein the retaining element can be in contact with the surface of the light source circuit board in which the light sources of the backlight unit are mounted. Therefore, in the display device according to the aspects of this disclosure, the particles generated during the coupling process of the retaining element cannot interfere with the light emitted by the backlight unit. This can improve the image quality in the display device according to the aspects of this disclosure. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] KR 1020200186540

[0001]

Claims

[1] Display device (DP) which includes: a backlighting unit (200) comprising a second light guide plate (222) arranged on a first light guide plate (221) and a light source element (210), a liquid crystal panel (100) on the second light guide plate (222) of the backlight unit (200), a first viewing angle control unit (410) arranged between the first light guide plate (221) and the second light guide plate (222) of the backlight unit (200), the first viewing angle control unit (410) having first light-blocking patterns (413), and a retaining element (500) that is arranged between an edge of the first light guide plate (221) and an edge of the first viewing angle control unit (410), wherein the light source element (210) comprises a first light source (211) on one side of the first light guide plate (221), a second light source (212) on one side of the second light guide plate (222) and a light source circuit plate (213) in which the first light source (211) and the second light source (212) are mounted, and wherein the retaining element (500) is in contact with a surface of the light source circuit board (213) between the first light source (211) and the second light source (212). [2] Display device (DP) according to claim 1, wherein the retaining element (500) comprises a metallic material. [3] Display device (DP) according to claim 1 or 2, wherein a lower surface of the first viewing angle control unit (410) has a region in the direction of the first light guide plate (221) which is in contact with the retaining element (500). [4] Display device (DP) according to any one of claims 1 to 3, wherein the backlight unit (200) further comprises an optical film (230a) between the first light guide plate (221) and the first viewing angle control unit (410), and wherein an upper surface of the optical film (230a) in the direction of the first viewing angle control unit (410) has a region which is in contact with the retaining element (500). [5] Display device (DP) according to any one of claims 1 to 4, wherein the light source circuit board (213) has a first light source area (LA1) in which the first light source (211) is mounted, a second light source area (LA2) in which the second light source (212) is mounted, and an intermediate area (MA) between the first light source area (LA1) and the second light source area (LA2), wherein the retaining element (500) is in contact with the intermediate area (MA) of the light source circuit board (213), and wherein the second light source area (LA2) is arranged at a distance from the intermediate area (MA). [6] Display device (DP) according to claim 5, wherein the intermediate area (MA) is in contact with the first light source area (LA1). [7] Display device (DP) according to claim 5 or 6, wherein the light source circuit board (213) further comprises a connection area (CA) which is in contact with one side of the first light source area (LA1) and one side of the second light source area (LA2). [8] Display device (DP) according to any one of claims 1 to 7, which further comprises a second viewing angle control unit (420) arranged between the backlight unit (200) and the liquid crystal panel (100), wherein the second viewing angle control unit (420) has second light-blocking patterns (423) extending in a direction perpendicular to the first light-blocking patterns (413). [9] Display device (DP) which includes: at least one first light source (211) on one side of a first light guide plate (221), a viewing angle control unit (410) arranged on the first light guide plate (221), wherein the viewing angle control unit (410) has light-blocking patterns (413), a second light guide plate (222) on the viewing angle control unit (410), wherein the second light guide plate (222) overlaps with the first light guide plate (221), at least one second light source (212) on one side of the second light guide plate (222), a liquid crystal panel (100) on the second light guide plate (222), a light source circuit board (213) which has an intermediate area (MA) between a first light source area (LA1) in which the at least one first light source (211) is mounted and a second light source area (LA2) in which the at least one second light source (212) is mounted, and a retaining element (500) that is in contact with the intermediate area (MA) of the light source circuit board (213), wherein the retaining element (500) extends between an edge of the first light guide board (221) and an edge of the viewing angle control unit (410). [10] Display device (DP) according to claim 9, which further comprises a cover base (250) that accommodates the first light guide plate (221), the at least one first light source (211), the viewing angle control unit (410), the second light guide plate (222), the at least one second light source (212), the light source circuit board (213) and the retaining element (500), wherein the cover base (250) has a side wall (252) which is arranged on one side of the first light guide plate (221) and on one side of the second light guide plate (222), and wherein the light source circuit board (213) is attached to the side wall (252) of the cover base (250) by means of a substrate adhesive layer (260). [11] Display device (DP) according to claim 9 or 10, wherein the intermediate area (MA) of the light source circuit board (213) has at least one coupling hole (213h), and wherein the retaining element (500) has at least one projecting section (500p) which is attached to the at least one coupling hole (213h) of the light source circuit board (213). [12] Display device (DP) according to claim 11, which further comprises an element adhesive layer (510) arranged between the light source circuit board (213) and the retaining element (500), wherein the element adhesive layer (510) has at least one through hole (510h) through which the protruding section (500p) of the retaining element (500) passes. [13] Display device (DP) according to claim 11 or 12, wherein the retaining element (500) comprises an insulating material. [14] Display device (DP) according to any one of claims 9 to 13, wherein the retaining element (500) has a rod shape extending along an edge of the viewing angle control unit (410). [15] Display device (DP) according to any one of claims 9 to 14, further comprising an air gap (AG) arranged between the first light guide plate (221) and the viewing angle control unit (410), wherein the air gap (AG) is arranged side by side with the retaining element (500).

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