An anisotropic light guide plate having a concave groove structure, a backlight module, and a display device

Abstract

Provided are a special-shaped light guide plate having a concave groove structure, a backlight module, and a display device, which can achieve excellent light uniformity when light is incident on the special-shaped light guide plate. 【Solution means】The backlight module includes a special-shaped light guide plate 10 having a concave groove structure. The display device includes the backlight module. The special-shaped light guide plate is provided with a dimming unit 12 in a concave groove 115 on the light-incident side 113 of its plate body 11. The first reflection part 121 of the dimming unit is provided between two second reflection parts 122, and the first reflection part and the second reflection part have different dimming characteristics. When light is incident on the special-shaped light guide plate, by arranging the first reflection part and the second reflection part with different dimming characteristics on the peripheral wall of the concave groove, the brightness difference in the area around the concave groove of the plate body is adjusted.

Description

Technical Field

[0001] The present invention relates to a light guide plate, and particularly to a deformed light guide plate applied to a backlight module in a display device.

Background Art

[0002] Currently, many existing display devices are liquid crystal display devices with geometric shapes such as rectangles and polygons on their outer shapes. The liquid crystal panel of the liquid crystal display device provides a backlight by a backlight module. Since the light guide plate in the backlight module is provided with concave grooves on the edge of its plate body, the distance between the edge of the plate body of the light guide plate and the side light source does not match the distance between the peripheral wall of the concave groove and the side light source. As a result, when the light rays emitted from the side light source of the backlight module are projected into the light guide plate, reflected, and emitted, the region of the plate body of the light guide plate close to the concave groove has a short distance to the side light source, resulting in a bright region with high luminance.

[0003] In order to ensure the screen display quality, further overcoming is required for the problem of the brightness difference caused by the provision of the concave grooves on the light guide plate.

Summary of the Invention

[0004] An object of the present invention is to provide a deformed light guide plate, a backlight module, and a display device having a concave groove structure for solving the technical problem of the brightness difference occurring in the peripheral wall region of the concave groove on the anti-incident light side in the light guide plate of the existing backlight module.

[0005] To achieve the above object, the deformed light guide plate having a concave groove structure proposed by the present invention includes a light-emitting surface, a light-incident side and an anti-incident light side located on both opposite sides of the light-emitting surface, and a plate body having a concave groove extending from the anti-incident light side toward the light-incident side. A dimming unit provided in the concave groove, including a first reflecting portion and two second reflecting portions, wherein the first reflecting portion and the second reflecting portions have different dimming characteristics, and the first reflecting portion is provided between the two second reflecting portions.

[0006] To achieve the above object, the backlight module proposed by the present invention is An irregular light guide plate as described above, A light source provided outside the light incident side of the irregular light guide plate and capable of irradiating light onto the light incident side, At least one optical film provided on the light emitting surface of the irregular light guide plate.

[0007] To achieve the above object, the display device proposed by the present invention is A backlight module as described above, A display panel provided on the optical film of the backlight module.

[0008] According to the creation of the irregular light guide plate, backlight module and display device having the above-mentioned concave groove structure, mainly, a dimming unit is provided in the concave groove on the light anti-incident side of the plate body of the irregular light guide plate. The dimming unit has a first reflecting portion and two second reflecting portions. The first reflecting portion is located between the two second reflecting portions, and by using an irregular light guide plate in which the first reflecting portion and the second reflecting portions have different dimming characteristics, when light enters the irregular light guide plate, the first reflecting portion and the second reflecting portions with different dimming characteristics are arranged at different positions on the peripheral wall of the concave groove to provide differentiated dimming performance. After the light enters the plate body, the brightness difference in the peripheral area of the concave groove is adjusted, so that excellent light uniformity can be achieved when light enters the irregular light guide plate.

[0009] In the present invention, further, by utilizing the fact that the parallel reflectance of the first reflecting portion is greater than the parallel reflectance of the second reflecting portion, or the light absorption rate of the first reflecting portion is greater than the light absorption rate of the second reflecting portion, the first reflecting portion and the second reflecting portion disposed on the peripheral wall of the concave groove utilize the difference in parallel reflectance or the change in the difference in light absorption rate, thereby enabling adjustment of the brightness of different regions around the concave groove of the plate body.

[0010] In the present invention, further, reflection sheets are respectively provided on the light incident side opposite to the plate body and on two side edges. By providing the reflection sheets, the light rays irradiated on the light incident side opposite to the plate body and on the two side edges are reflected back to the plate body again, improving the light energy utilization rate of the irregular light guide plate. At the same time, by providing reflection sheets on the light incident side opposite to the plate body and on the two side edges respectively, it supports the dimming performance of the peripheral region of the concave groove by the dimming unit disposed on the peripheral wall of the concave groove of the plate body, and can improve the light emission luminance and uniformity of the irregular light guide plate.

[0011] In the present invention, further, it is defined that there is a first distance between the light incident side opposite to the plate body and the light incident side, and there is a second distance between the concave groove and the light incident side. It is controlled such that the first ratio of the second distance to the first distance is 0.15 or more and 0.5 or less (including both end values). Alternatively, it is defined that the light incident side opposite to the plate body has a first width, and the concave groove has a second width. It is controlled such that the second ratio of the second width to the first width is 0.25 or more and 0.7 or less (including both end values). Thereby, the influence of the concave groove of the irregular light guide plate on the uniformity of the light emitting surface on the light incident side opposite to the plate body is reduced. Further, by combining with the dimming unit installed in the concave groove of the irregular light guide plate, better dimming performance can be achieved, and the light emission luminance and uniformity of the irregular light guide plate can be improved.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0013] Based on the content described in the above-mentioned outline of the invention, the present invention includes a deformed light guide plate having a concave groove structure, a backlight module, and a display device. Hereinafter, with reference to the drawings, specific structures such as the deformed light guide plate, the backlight module, and the display device will be described respectively.

[0014] As shown in FIGS. 1 to 3, an embodiment of a deformed light guide plate 10 having a concave groove structure according to the present invention is disclosed. The deformed light guide plate 10 includes a plate body 11 and a dimming unit 12.

[0015] As shown in FIGS. 1 and 3, the plate body 11 includes a light-emitting surface 111, a light-incident side 112 and a non-light-incident side 113 located on both opposite sides of the light-emitting surface 111. The plate body 11 further has two side edges 114 located between the light-incident side 112 and the non-light-incident side 113, and a back side 116 located on the opposite side of the light-emitting surface 111. The plate body 11 has a concave groove 115 extending from the non-light-incident side 113 towards the light-incident side 112. The concave groove 115 penetrates from the light-emitting surface 111 to the back side 116. At a location adjacent to the non-light-incident side 113 of the plate body 11, the concave groove 115 provides a space for accommodating external elements, such as human-computer interaction elements such as an image capture element, a sensing element, or a combination thereof.

[0016] The dimming unit 12 is specifically used to reduce the brightness difference of light rays in the peripheral area of the concave groove 115 of the plate body 11. As shown in FIG. 2, the dimming unit 12 is provided in the concave groove 115 of the plate body 11 and includes a first reflection part 121 and two second reflection parts 122. The first reflection part 121 is provided between the two second reflection parts 122. The first reflection part 121 and the two second reflection parts 122 may each be independent members, or the first reflection part 121 and the two second reflection parts 122 may be integrated into a single member. In the dimming unit 12, the first reflection part 121 and the second reflection part 122 have different dimming characteristics. By providing the first reflection part 121 and the second reflection part 122 having different dimming characteristics at different positions on the peripheral wall of the concave groove 115 of the plate body 11, a differentiated dimming performance can be provided, and the brightness difference of light rays in the peripheral area of the concave groove 115 of the plate body 11 can be effectively reduced.

[0017] As shown in FIGS. 1 to 3, in addition to traveling in the direction of the light exit side 113 from the light incident side 112 of the plate body 11 of the irregular light guide plate 10, the light rays incident from the light incident side 112 are generally guided to the light exit surface 111 and emitted by utilizing total internal reflection by the plate body 11. By providing the concave groove 115 on the light non-incident side 113 of the plate body 11, the total internal reflection performance of the plate body 11 of the original rectangular shape with respect to the light rays changes. When the dimming unit 12 is not provided in the concave groove 115, the peripheral region adjacent to the concave groove 115 of the plate body 11 is close to the light incident side 112, and a bright region with high luminance is generated.

[0018] The shape and size of the concave groove 115 are set according to the needs of the product. In the embodiment shown in FIG. 2, the concave groove 115 includes a groove bottom wall 1151 and two groove side walls 1152 located on both sides of the groove bottom wall 1151, and the groove bottom wall 1151 faces the light incident side 112. According to the fact that the groove bottom wall 1151 is at a position facing the light incident side 112 of the concave groove 115, the distance from the groove bottom wall 1151 to the light incident side 112 is smaller than the distance from the light non-incident side 113 to the light incident side 112. Regarding the peripheral wall of the concave groove 115, since the distance between the groove bottom wall 1151 and the light incident side 112 is close, after the light enters, the luminance in the region adjacent to the groove bottom wall 1151 of the plate body 11 is greater than the luminance in the region adjacent to the groove side wall 1152 of the plate body 11. Both the groove bottom wall 1151 and the groove side wall 1152 are linear wall surfaces, and the included angle θ between the groove bottom wall 1151 and the adjacent groove side wall 1152 may be a right angle or an obtuse angle, that is, the included angle θ between the groove bottom wall 1151 and the adjacent groove side wall 1152 is not an acute angle. In this way, the light rays from the light incident side 112 can directly contact the light non-incident side 113, the groove bottom wall 1151 and the groove side wall 1152 of the concave groove 115 without any obstacles. On the contrary, when the included angle θ is an acute angle, since the light rays can only travel linearly, dead angles where uniform transmission cannot occur may be generated. In this case, obvious chipping will occur on the plate body 11 of the irregular light guide plate 10.

[0019] As shown in FIG. 2, in this embodiment, the first reflection portion 121 is located on the groove bottom wall 1151 of the concave groove 115, and the two second reflection portions 122 are respectively located on the two groove side walls 1152. By utilizing the parallel reflection characteristic of light or the light absorption characteristic of the light of the dimming unit 12 on the peripheral wall of the concave groove 115 of the plate body 11 to adjust the brightness difference in the peripheral area of the concave groove 115, the desired light uniformity can be achieved. In this embodiment, in order to effectively improve the brightness difference at different parts of the concave groove 115 of the plate body 11 after light enters, in the dimming unit 12 provided in the concave groove 115, the first reflection portion 121 and the second reflection portion 122 having different dimming characteristics can be set such that the parallel reflectivity of the first reflection portion 121 is greater than the parallel reflectivity of the second reflection portion 122. Alternatively, it can be set such that the light absorption rate of the first reflection portion 121 is greater than the light absorption rate of the second reflection portion 122.

[0020] For example, when selecting an embodiment in which the parallel reflectivity of the first reflection portion 121 is greater than the parallel reflectivity of the second reflection portion 122, a white reflection sheet is used as the second reflection portion 122, and a silver reflection sheet having a high parallel reflectivity is used as the first reflection portion 121. By utilizing the fact that the first reflection portion 121 is located on the groove bottom wall 1151 of the concave groove 115, high parallel reflection performance is provided for the light from the light incident side 112, the light rays irradiated on the groove bottom wall 1151 are appropriately reflected to adjust the reflection angle of the light, and the brightness difference in the peripheral area of the concave groove 115 can be adjusted. When selecting an embodiment in which the light absorption rate of the first reflection portion 121 is greater than the light absorption rate of the second reflection portion 122, a white reflection sheet is used as the second reflection portion 122, and a gray reflection sheet having a high light absorption rate is used as the first reflection portion 121. The gray reflection sheet may refer to the reflection surface of any gradation value among the gradation changes from white to black in the gray scale image. By utilizing the fact that the first reflection portion 121 is located on the groove bottom wall 1151 of the concave groove 115, high light absorption dimming performance is provided for the light from the light incident side 112, and the brightness difference in the peripheral area of the concave groove 115 can be adjusted.

[0021] As shown in FIGS. 1 and 2, the irregular light guide plate 10 may further include reflection sheets 123 on the light incident side 113 and the two side edges 114 of the plate body 11 respectively. By providing the reflection sheets 123, the light rays irradiated on the light incident side 113 and the two side edges 114 can be reflected back to the plate body 11 again, and the light energy utilization rate of the irregular light guide plate 10 can be improved. At the same time, by providing the reflection sheets 123 on the light incident side 113 and the two side edges 114 of the plate body 11 respectively, the dimming performance of the peripheral area of the concave groove 115 by the dimming unit 12 arranged on the peripheral wall of the concave groove 115 of the plate body 11 can be assisted, and the light emission luminance and uniformity of the irregular light guide plate 10 can be improved.

[0022] As shown in FIGS. 1 and 2, examples of the reflection sheets 123 provided on the light incident side 113 and the two side edges 114 of the plate body 11 include silver reflection sheets, white reflection sheets, or other reflection sheets with high reflectivity. In this embodiment, the dimming characteristics of the reflection sheet 123 are the same as those of the second reflection portion 122. When a white reflection sheet is used for the second reflection portion 122, the reflection sheet 123 also uses a white reflection sheet, but it is not limited thereto.

[0023] As described above, in the present invention, the main purpose of making the dimming characteristics of the reflection sheet 123 the same as those of the second reflection portion 122 is to enable the process of making the light rays consistent with the reflection sheets 123 having the same optical characteristics at the edges other than the groove bottom wall 1151 of the concave groove 115 in the irregular light guide plate 10, for example, the groove side wall 1152, the light incident side 113, and the side edge 114, thereby ensuring the luminance consistency of the light emitting surface 111 in other regions of the irregular light guide plate 10. Therefore, under the same light reflection conditions or light absorption conditions, it is only necessary to adjust the light rays to the groove bottom wall 1151 at the first reflection portion 121, and there is no need for excessive trial and error to achieve the effect of the light emission uniformity of the entire light emitting surface 111.

[0024] In terms of product applications, the irregular light guide plate according to the present invention is applicable to products such as mobile phones, tablets, computers, displays, or in-vehicle products. For example, in the process of human-computer interaction between a vehicle and a driver, it is necessary to sense the driver's instructions or messages by using sensors or camera modules installed in the display located in front of the driver's seat. Therefore, the size of the concave groove of the irregular light guide plate in in-vehicle products is larger than the size of the irregular light guide plate in mobile phones. Referring to FIG. 4, in an embodiment where the irregular light guide plate according to the present invention is applied to an in-vehicle product, there is a first distance D1 between the light-receiving side 113 and the light-incident side 112 of the plate body 11, and there is a second distance D2 between the concave groove 115 and the light-receiving side 113. The first ratio of the second distance D2 to the first distance D1 is 0.15 or more and 0.5 or less. More specifically, the second distance D2 refers to the distance from the groove bottom wall 1151 of the concave groove 115 to the light-receiving side 113.

[0025] Referring to FIGS. 5 and 6, in another embodiment of the irregular light guide plate according to the present invention, the light-receiving side 113 of the plate body 11 has a first width W1, the concave groove 115 has a second width W2, and the second ratio of the second width W2 to the first width W1 is 0.25 or more and 0.7 or less. The first width W1 of the light-receiving side 113 may refer to the distance between two opposing side edges 114. The second width W2 of the concave groove 115 may be the width of the groove bottom wall 1151 of the concave groove 115 or the opening width of the entire concave groove 115, but here it is not limited to the width of the groove bottom wall 1151. More specifically, in in-vehicle products, usually, high brightness and low power consumption are required. Therefore, by combining the dimming unit 12 provided in the concave groove 115 in the irregular light guide plate 10 disclosed in the present invention, light rays can contact the first reflecting portion 121, the second reflecting portion 122, and the reflecting sheet 123 having different dimming characteristics in different regions, return to the irregular light guide plate 10, and then be emitted. Thereby, not only can the hot spot problem in the region close to the groove bottom wall 1151 of the concave groove 115 be solved, but also the requirements of uniformity and low power consumption required for each model of the in-vehicle display device can be satisfied.

[0026] On the other hand, in the backlight module of a small mobile phone, when an aperture is provided in the light guide plate to mount the front camera, the ratio of the distance (i.e., length) from the light-incident side to the light-emitting side of the light guide plate (i.e., length) to the distance (i.e., length) from the aperture to the light-incident side is usually less than 0.2, or the ratio of the width between both side edges of the light guide plate to the diameter of the aperture is known to be less than 0.07. The light guide plate of a small mobile phone that satisfies the above specifications usually uses a mode without attaching any reflective sheet, and directly passes the concave groove without reflecting the light rays in the light guide plate, so as to meet the uniformity requirement of the light-emitting surface.

[0027] As shown in FIG. 7, an embodiment of the backlight module 1 of the present invention is disclosed. The configuration and structure of the backlight module 1 in the present invention include a deformed light guide plate 10, a light source 20, and at least one optical film 30. The specific shape and structure of the deformed light guide plate 10 are as described above, and will not be repeated here.

[0028] As shown in FIG. 7, the light source 20 is provided outside the light-incident side 112 of the deformed light guide plate 10, and irradiates light on the light-incident side 112 of the plate body 11, so that the incident light rays are uniformly emitted from the light-emitting surface 111 of the plate body 11 due to the light guiding performance such as total reflection of the light of the plate body 11. As the light source 20, an LED light bar including a plurality of LED light-emitting elements may be used so as to achieve effects such as low power consumption and long life.

[0029] As shown in FIG. 7, the optical film 30 is one or more sheets and may have specific optical properties. Generally, as the optical film 30, a diffusion sheet having light diffusion properties, a brightness enhancement sheet having brightness enhancement properties, a prism sheet having properties for guiding the turning of light, or the like may be used. The number of sheets of the optical film 30 and the selection of its optical properties are set according to the usage needs of the backlight module 1. The optical film 30 is provided on the light-emitting surface 111 of the irregular light guide plate 10, and the shape of the optical film 30 coincides with the shape of the plate body 11 having the concave grooves 115 of the irregular light guide plate 10. The light emitted from the light source 20 is guided by the irregular light guide plate 10 and then emitted. Subsequently, through light diffusion and brightness enhancement by the optical film 30, etc., the light-emitting brightness and uniformity of the backlight module 1 are improved.

[0030] As shown in FIG. 8, an embodiment of the display device according to the present invention is disclosed. The configuration and structure of the display device according to the present invention include a backlight module 1 and a display panel 4. The display panel 4 is provided on the optical film 30 of the backlight module 1. The display panel 4 is a liquid crystal panel. The backlight module 1 provides a backlight source 20. The shape of the display panel 4 coincides with the shape of the irregular light guide plate 10. The display panel 4 has a notch 40 that coincides with the concave groove 115 of the irregular light guide plate 10. The display device can mount external elements such as an image capture element, a sensing element, or a combination of the image capture element and the sensing element in a space formed by the concave groove 115 of the corresponding irregular light guide plate 10 and the notch 40 of the display panel 4. Thereby, due to the overall modular structure, it facilitates mounting a display device including an image capture element, a sensing element, or a combination thereof in the instrument area of an automobile and connecting it to an in-vehicle computer. The present invention can be widely applied to various models of side-light type in-vehicle display devices, and can be particularly widely applied to electric vehicles and smart driving cabins, etc. The display device according to the present invention can meet the mounting requirements of a plurality of external elements for human-computer interaction in electric vehicles and smart driving cabins.

Description of Reference Numerals

[0031] 1: Backlight module 10: Irregular light guide plate 11: Plate body 111: Light-emitting surface 112: Light-incident side 113: Anti-light-incident side 114: Side 115: Concave groove 1151: Groove bottom wall 1152: Groove side wall 116: Back side θ: Angle between the groove bottom wall and the groove side wall 12: Dimming unit 121: First reflection part 122: Second reflection part 123: Reflective sheet 20: Light source 30: Optical film 4: Display panel 40: Notch D1: First distance from the light-reverse entry side to the light entry side D2: Second distance from the concave groove to the light-reverse entry side W1: First width on the light-reverse entry side W2: Second width of the concave groove

Claims

1. A plate body including a light-emitting surface, a light-incident side and a non-light-incident side located on both opposite sides of the light-emitting surface, and having a concave groove extending from the non-light-incident side toward the light-incident side; A dimming unit provided in the concave groove and including a first reflection portion and two second reflection portions, wherein the first reflection portion and the second reflection portions have different dimming characteristics, and the first reflection portion is provided between the two second reflection portions, and a special-shaped light guide plate having a concave groove structure.

2. The special-shaped light guide plate having a concave groove structure according to Claim 1, wherein the parallel reflectivity of the first reflection portion is greater than the parallel reflectivity of the second reflection portion.

3. The special-shaped light guide plate having a concave groove structure according to Claim 1, wherein the light absorption rate of the first reflection portion is greater than the light absorption rate of the second reflection portion.

4. The concave groove includes a groove bottom wall and two groove side walls located on both sides of the groove bottom wall. The groove bottom wall and the groove side walls are both straight walls. The first reflection portion is provided on the groove bottom wall, the second reflection portion is provided on the groove side wall, and the included angle between the groove side wall adjacent to the groove bottom wall is not an acute angle. The special-shaped light guide plate having a concave groove structure according to Claim 1.

5. The special-shaped light guide plate having a concave groove structure according to Claim 1, having a first distance between the non-light-incident side and the light-incident side, a second distance between the concave groove and the non-light-incident side, and a first ratio of the second distance to the first distance is 0.15 or more and 0.5 or less.

6. The special-shaped light guide plate having a concave groove structure according to Claim 1, wherein the non-light-incident side has a first width, the concave groove has a second width, and a second ratio of the second width to the first width is 0.25 or more and 0.7 or less.

7. A special-shaped light guide plate according to any one of Claims 1 to 6; A light source provided outside the light-incident side of the special-shaped light guide plate and capable of irradiating light onto the light-incident side; At least one optical film provided on the light-emitting surface of the special-shaped light guide plate, and a backlight module.

8. A backlight module according to Claim 7; A display device including a display panel provided on the optical film of the backlight module.

9. The display device according to Claim 8, wherein the display panel has a notch corresponding to the concave groove of the special-shaped light guide plate, and an image capture element, a sensing element or a combination thereof can be mounted on the notch and the concave groove.

Images