Front light module and display device
By designing multiple inner concave dot structures in the front light module of the electronic ink screen, the problem of limited use of EPDs under low -light conditions is solved, and higher brightness and contrast are achieved.
Patent Information
- Application Number
- CN202420383349.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-28
- Publication Date
- 2025-01-28
- Estimated Expiration
- 2034-02-28
AI Technical Summary
Existing electronic ink screens (EPDs) are limited in use in dark or weak light, and their visibility in low-light conditions is needed.
Design a front light module, including transparent cover, light guide plate, and light source. There are multiple inner concave dot structures on the light guide plate. The dot structure and the cover plate form an empty cavity to enhance the reflection and transmission effect of the light.
By enhancing the reflection and transmission of light, the brightness and contrast of the front light module are improved, and the visibility of the low light conditions is improved.
Smart Images
Figure CN222420584U_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of display technology, and more specifically, to a front light module and a display device. Background Art
[0002] With the development of technology, there are more and more types of display screens. Among them, electronic ink display (EPD) is becoming more and more widely used due to its eye-protection properties.
[0003] Based on the display characteristics of EPD, its contrast is low and it needs to be visible in the presence of light, which limits the use of EPD products in dark or low-light conditions. It is necessary to improve it. Utility Model Content
[0004] The present disclosure aims to provide a front light module and a display device to solve at least one of the problems existing in the prior art.
[0005] In order to achieve the above objectives, the present invention adopts the following technical solutions:
[0006] A first aspect of the present disclosure provides a front light module, the front light module comprising a transparent cover plate, a light guide plate, and a light source;
[0007] The light guide plate has a light incident surface, a light emitting surface and a bottom surface, and the light incident surface is connected between the light emitting surface and the bottom surface;
[0008] The light source is arranged on one side of the light incident surface of the light guide plate;
[0009] The transparent cover plate is arranged on one side of the light emitting surface of the light guide plate;
[0010] The light emitting surface of the light guide plate has a plurality of concave mesh structures, and a cavity is formed between the transparent cover plate and the mesh structure;
[0011] The lattice structure comprises a light-facing surface and a backlight surface, and a light-facing angle formed by the light-facing surface and the transparent cover plate is 35° to 42°.
[0012] In a possible implementation manner, a backlight angle formed by the backlight surface and the transparent cover plate is 18° to 25°.
[0013] In a possible implementation manner, the depression depth of the mesh dot structure is 5.5 μm to 6.5 μm.
[0014] In a possible implementation manner, a length of the mesh dot structure in a direction perpendicular to the light incident surface is 28 μm to 34 μm.
[0015] In a possible implementation manner, a length of the mesh dot structure in a direction parallel to the light incident surface is 20 μm to 26 μm.
[0016] In a possible implementation, a gap between the light source and the light incident surface of the light guide plate is less than or equal to 0.15 mm.
[0017] In a possible implementation, the front light module further includes a light-shielding tape, which is disposed on a side of the light guide plate close to the cover plate and is adhered to cover a gap between the light source and the light guide plate and to cover the light source.
[0018] In a possible implementation, the front light module further includes a light-shielding frame covering the light guide plate and the light source.
[0019] A second aspect of the present disclosure provides a display device, including the front light module and the ink screen provided by the first aspect of the present disclosure, wherein:
[0020] The front light module is covered on the ink screen.
[0021] In a possible implementation, the display device further includes a touch layer, and the touch layer is disposed on a side of the ink screen away from the front light module.
[0022] The beneficial effects of the present disclosure are as follows:
[0023] In the front light module provided by the present disclosure, a light guide plate is provided with a plurality of recessed mesh dot structures, and a cavity is formed between the mesh dot structure and the cover plate. The cavity can allow the incident light to be fully reflected, thereby increasing the effective amount of illumination light and improving the brightness and contrast of the front light module. By designing the light-facing angle formed by the light-facing surface of the mesh dot structure, the brightness and contrast of the front light module are further improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The specific implementation methods of the present disclosure are further described in detail below with reference to the accompanying drawings.
[0025] Figure 1 A schematic structural diagram of a front light module provided in the first embodiment of the present disclosure is shown.
[0026] Figure 2 Three views of the dot structure provided by the first embodiment of the present disclosure are shown.
[0027] Figure 3-5 The relationship curves between the incident light angle of the dot structure and the illumination, total brightness and center brightness of the front light module are shown respectively.
[0028] Figure 6-8 The relationship curves between the backlight angle of the dot structure and the front light module, the total brightness and the center brightness are shown respectively.
[0029] Figure 9-11 The relationship curves between the depression depth of the dot structure and the front light module, the total brightness and the center brightness are shown respectively.
[0030] Figure 12-14 The relationship curves between the length of the dot structure in the direction perpendicular to the light incident surface and the front light module, the total brightness and the center brightness are respectively shown.
[0031] Figure 15-17 The relationship curves between the length of the dot structure in the direction parallel to the light incident surface and the front light module, the total brightness and the center brightness are respectively shown.
[0032] Fig.18 A schematic structural diagram of a display device provided in a second embodiment of the present disclosure is shown. DETAILED DESCRIPTION
[0033] The terms “on”, “formed on” and “disposed on” in the present disclosure may mean that one layer is directly formed or disposed on another layer, or may mean that one layer is indirectly formed or disposed on another layer, i.e., there are other layers between the two layers.
[0034] It should be noted that, although the terms "first", "second", etc. may be used herein to describe various parts, components, elements, regions, layers and / or parts, these parts, components, elements, regions, layers and / or parts should not be limited by these terms. Instead, these terms are used to distinguish one part, component, element, region, layer and / or part from another. Thus, for example, the first part, first member, first element, first region, first layer and / or first part discussed below may be referred to as the second part, second member, second element, second region, second layer and / or second part without departing from the teachings of the present disclosure.
[0035] In the present disclosure, unless otherwise specified, the term "same-layer arrangement" used refers to two layers, parts, components, elements or parts that can be formed by the same preparation process (such as a patterning process, etc.), and the two layers, parts, components, elements or parts are generally formed of the same material. For example, two or more functional layers are arranged in the same layer, which means that these functional layers arranged in the same layer can be formed using the same material layer and the same preparation process, thereby simplifying the preparation process of the display substrate.
[0036] In the present disclosure, unless otherwise specified, the expression "patterning process" generally includes steps such as photoresist coating, exposure, development, etching, photoresist stripping, etc. The expression "one-time patterning process" means a process of forming patterned layers, components, members, etc. using one mask.
[0037] Figure 1A cross-sectional schematic diagram of a front light module is provided for the first embodiment of the present disclosure, referring to Figure 1 The front light module provided in the present disclosure includes: a light guide plate 102, a light source 101 and a cover plate 104, wherein:
[0038] The light guide plate 102 has a light incident surface 102B, a light emitting surface 102A and a bottom surface 102C, wherein the light incident surface 102B connects the light emitting surface 102A and the bottom surface 102C, and the light emitting surface 102A is provided with a plurality of concave mesh structures 1021;
[0039] The light source 101 is disposed on one side of the light incident surface 102B to provide light, and the light is incident from the light source 101 into the light guide plate 102;
[0040] Specifically, the light source 101 is, for example, a light strip formed by a plurality of light-emitting lamp beads, and the light source 101 is, for example, bonded to the light incident surface of the light guide plate through an optical adhesive layer 103;
[0041] In this implementation, the light emitting surface 102A of the light guide plate 102 is provided with a plurality of mesh structures 1021 recessed toward the bottom surface 102C of the light guide plate 102, such as Figure 2 As shown, the concave shape of the mesh structure 1021 is, for example, a triangular prism, and the mesh structure 1021 has a light-facing surface 1021A and a backlight surface 1021B, wherein the light-facing surface 1021A of each mesh structure is arranged away from the light source 101 relative to the backlight surface 1021B;
[0042] Through simulation verification and comprehensive analysis of the total luminous flux, total brightness and center point brightness of the front light module, the light-facing angle α formed by the light-facing surface 1021A and the first plane is greater than or equal to 35° and less than or equal to 42°.
[0043] The light guide plate in the front light module provided by the present invention is provided with a plurality of recessed mesh dot structures, and a cavity is formed between the mesh dot structure and the cover plate. The cavity can allow the incident light to be fully reflected, thereby increasing the effective amount of lighting light, and improving the total luminous flux, brightness and center point brightness of the front light module, thereby improving the contrast of the front light module. By designing the light-facing angle formed by the light-facing surface of the mesh dot structure, the total luminous flux, total brightness and center point brightness of the front light module are further improved.
[0044] like Figure 2 As shown, Figure 2 (a) is a top view of the concave portion of the dot structure, Figure 2 (b) is a side view of the recessed portion of the dot structure, Figure 2(c) is a front view of the recessed portion of the dot structure, wherein the length of the dot structure in a direction perpendicular to the light source is X, the length of the dot structure in a direction parallel to the light source is Y, and the recessed depth of the dot structure is H.
[0045] The light guide plate in the front light module provided by the present invention is provided with a plurality of recessed mesh dot structures, and a cavity is formed between the mesh dot structure and the cover plate. The cavity can allow the incident light to be fully reflected, thereby increasing the effective amount of lighting light, and improving the total luminous flux, brightness and center point brightness of the front light module, thereby improving the contrast of the front light module. By designing the light-facing angle formed by the light-facing surface of the mesh dot structure, the total luminous flux, total brightness and center point brightness of the front light module are further improved.
[0046] Specifically, the relationship between the incident light angle α and the luminance is simulated by optical simulation software, and the following is obtained: Figure 3 The curve diagram shown by Figure 3 It can be seen that when the incident angle α is 36°, the illuminance value of the front light module is the largest, wherein the illuminance is the luminous flux irradiated by the front light module onto a unit area. When the area is constant, the greater the illuminance value, the higher the luminous flux.
[0047] Specifically, the relationship between the incident light angle α and the total brightness (Total Power) is simulated by optical simulation software, and the following is obtained: Figure 4 The relationship curve shown is Figure 4 It can be seen that when the incident light angle α is 40°, the total brightness of the front light module is the largest.
[0048] Specifically, the relationship between the incident light angle α and the center brightness (Center Brightness) is simulated by optical simulation software, and the following is obtained: Figure 5 The relationship curve shown is Figure 5 It can be seen that when the incident light angle α is 42°, the central brightness of the front light module is the maximum.
[0049] It should be noted that the incident light angle of the dot structure can be selected within the above range according to customer requirements and is not specifically limited here.
[0050] In a possible implementation, after simulation verification, the total luminous flux, total brightness and center point brightness of the front light module are comprehensively analyzed, and based on these three considerations, the backlight angle β formed by the backlight surface and the first plane is limited to be greater than or equal to 18° and less than or equal to 25°.
[0051] It should be noted that the first plane is parallel to the bottom surface of the light guide plate.
[0052] In the front light module provided by the present disclosure, a light guide plate is provided with a plurality of recessed mesh dot structures, and a cavity is formed between the mesh dot structure and the cover plate. The cavity can allow the incident light to be fully reflected, thereby increasing the effective amount of illumination light and improving the brightness and contrast of the front light module. By designing the front light angle formed by the light-facing surface of the mesh dot structure and the backlight angle formed by the backlight surface, the total luminous flux, total brightness and center point brightness of the front light module are further improved.
[0053] Specifically, the relationship between the backlight angle β and the illumination is simulated by optical simulation software, and the following is obtained: Figure 6 The curve diagram shown by Figure 6 It can be seen that when the backlight angle β is 15°, the illumination value of the front light module is the largest, wherein the illumination is the luminous flux irradiated by the front light module onto a unit area. When the area is constant, the greater the illumination value, the higher the luminous flux.
[0054] Specifically, the relationship curve between the backlight angle β and the total brightness is obtained by simulating with optical simulation software, such as Figure 7 As shown, when the backlight angle is about 20°, the total brightness value of the front light module is the largest.
[0055] Specifically, the relationship curve between the backlight angle β and the center brightness is obtained by simulating with optical simulation software, such as Figure 8 As shown, when the backlight angle is about 30°, the central brightness value of the front light module is the largest, but when the backlight angle is 15°, the central brightness value of the front light module is almost zero.
[0056] It should be noted that the backlight angle β of the dot structure can be selected within the above range according to customer requirements and is not specifically limited here.
[0057] In this implementation, based on the above three relationship curves, the inventor defines the backlight angle β formed by the backlight surface and the first plane as about 20°, for example, the backlight angle β is greater than or equal to 18° and less than or equal to 25°.
[0058] In a possible implementation manner, a recess depth H of the mesh dot structure is 5 μm to 6 μm, for example, 5.3 μm, 5.5 μm or 5.8 μm.
[0059] In the front light module provided by the present disclosure, a light guide plate is provided with a plurality of recessed dot structures, and a cavity is formed between the dot structure and the cover plate. The cavity can allow the incident light to be fully reflected, thereby increasing the effective amount of illumination light and improving the brightness and contrast of the front light module. By designing the specific parameters of the dot structure, the front light angle formed by the light-facing surface of the dot structure, the backlight angle formed by the backlight surface, and the recess depth are limited, thereby further improving the total luminous flux, total brightness, and center point brightness of the front light module.
[0060] Specifically, the present disclosure uses optical simulation software to comprehensively analyze the relationship between the total light flux, total brightness, and center brightness of the front light module and the depression depth of the dot structure, and comprehensively analyzes the following three items:
[0061] Specifically, by simulating the relationship between the depression depth H and the illumination, we can obtain Fig. 9 The relationship curve shown by Fig. 9 It can be seen that when the depth of the recess is greater than or equal to 6 μm, the illumination of the front light module is maximum.
[0062] Specifically, by simulating the relationship between the depression depth and the total brightness, we can obtain Fig.10 The relationship curve shown by Fig.10 It can be seen that when the dot depth is greater than or equal to 6 μm, the total brightness of the front light module is the maximum.
[0063] Specifically, by simulating the relationship between the depression depth and the center brightness, we can obtain Fig.11 The relationship curve shown by Fig.11 It can be seen that when the dot depth is greater than or equal to 5.5 μm, the central brightness of the front light module is the maximum.
[0064] It should be noted that the depression depth of the dot structure can be selected within the above range according to specific requirements and is not specifically limited here.
[0065] In this implementation, Figure 9-11 According to the three relationship curves, the inventor defines the depression depth of the dot structure as about 6 μm. For example, the depression depth of the dot structure is greater than or equal to 5.5 microns and less than or equal to 6.5 μm.
[0066] In a possible implementation, a length X of the mesh dot structure in a direction perpendicular to the light incident surface is 28 μm to 34 μm; a length Y of the mesh dot structure in a direction parallel to the light incident surface is 20 μm to 26 μm.
[0067] In the front light module provided by the present disclosure, a light guide plate is provided with a plurality of recessed dot structures, and a cavity is formed between the dot structure and the cover plate. The cavity can allow the incident light to be fully reflected, thereby increasing the effective amount of illumination light and improving the brightness and contrast of the front light module. By designing the specific parameters of the dot structure, the light-facing angle formed by the light-facing surface of the dot structure, the backlight angle formed by the backlight surface, the recessed depth, and the length and width of the dot structure are limited, thereby further improving the total luminous flux, total brightness and center point brightness of the front light module.
[0068] Specifically, the relationship between the length X of the dot structure and the total luminous flux is simulated by optical simulation software, and the following is obtained: Fig.12 The relationship curve shown by Fig.12It can be seen that when the length of the dot structure in the direction perpendicular to the light incident surface is 32 μm, the illumination value of the front light module is the largest. The larger the illumination value of the front light module, the larger the corresponding total luminous flux.
[0069] Specifically, the relationship between the length of the dot structure and the total brightness is simulated by optical simulation software, and the following is obtained: Fig.13 The relationship curve shown by Fig.13 It can be seen that when the length of the dot structure in the direction perpendicular to the light incident surface is 32 μm, the total brightness of the front light module is the maximum.
[0070] Specifically, the relationship between the length of the dot structure and the center brightness is simulated by optical simulation software, and the following is obtained: Fig.14 The relationship curve shown by Fig.14 It can be seen that when the length of the dot structure in the direction perpendicular to the light incident surface is 32 μm, the central brightness of the front light module is the maximum.
[0071] Specifically, the relationship between the width Y of the dot structure and the total luminous flux is simulated by optical simulation software, and the following is obtained: Fig.15 The relationship curve shown by Fig.15 It can be seen that when the length of the dot structure in the direction parallel to the light incident surface is 23.5 μm, the illumination value of the front light module is the largest. The larger the illumination value of the front light module, the larger the corresponding total luminous flux.
[0072] Specifically, the relationship between the width of the dot structure and the total brightness is simulated by optical simulation software, and the following is obtained: Fig.16 The relationship curve shown by Fig.16 It can be seen that when the length of the dot structure in the direction parallel to the light incident surface is 22.5 μm, the total brightness of the front light module is the maximum.
[0073] Specifically, the relationship between the width of the dot structure and the center brightness is simulated by optical simulation software, and the following is obtained: Fig.17 The relationship curve shown by Fig.17 It can be seen that when the length of the dot structure in the direction parallel to the light incident surface is 23.5 μm, the central brightness of the front light module is the maximum.
[0074] In a possible implementation manner, the mesh dot structure is prepared by a transfer process.
[0075] Specifically, the designed dot morphology and arrangement are processed on a steel plate using a dot collision process to obtain a master plate; a nickel plate is used as a mold through electroplating; and finally, the dot arrangement on the mold is transferred to the light guide plate raw material through hot rolling to obtain a light guide plate with multiple concave dot structures.
[0076] In a possible implementation, a gap between the light source 101 and the light incident surface 102B of the light guide plate 102 is less than or equal to 0.15 mm.
[0077] In a possible implementation, the front light module further includes a cover glass, one side of the cover glass is disposed on optical adhesive and bonded to the light emitting surface of the light guide plate, and a cavity is formed between the recessed portion and the cover glass.
[0078] In a possible implementation, the entire surface of the cover glass 104 is provided with optical adhesive 103 to bond the light guide plate and the transparent cover plate.
[0079] In this implementation, the transparent cover plate is bonded to the light guide plate by full-surface bonding using optical adhesive, which improves bonding reliability and avoids the generation of Newton rings.
[0080] In a possible implementation, the front light module further includes a light-shielding tape, which is disposed on a side of the light guide plate close to the cover plate and is adhered to cover a gap between the light source and the light guide plate and to cover the light source.
[0081] Specifically, the light-shielding tape is, for example, a light-shielding black adhesive including an ink layer and a conductive adhesive layer, or a light-shielding black adhesive including an ink layer, a conductive adhesive layer and an aluminum-chromium alloy layer.
[0082] The aluminum-chromium alloy layer includes two metals, aluminum and chromium, and chromium can accelerate the oxidation process of aluminum and make the color of the first section of the aluminum-chromium alloy layer darker after oxidation, thereby reducing the reflectivity of the first section of the aluminum-chromium alloy layer and weakening the reflective effect. The intensity of light reflected by the aluminum-chromium alloy layer is reduced to a large extent, and the bright line at the edge of the shading tape is significantly weakened, thereby improving the display effect of the display device and improving the user experience.
[0083] In a possible implementation, the front light module further includes a light-shielding frame covering the light guide plate and the light source.
[0084] The shading frame is, for example, a four-sided shading tape that wraps the light guide plate and the light source.
[0085] A second embodiment of the present disclosure provides a display device, such as Fig.18 As shown, it includes the front light module and the ink screen 202 provided in the first embodiment, wherein the front light module is arranged on the ink screen, and the front light module and the ink screen can be bonded by optical glue.
[0086] The front light module includes a transparent cover plate 104, a light guide plate 102, and a light source 101;
[0087] The light guide plate 102 has a light incident surface, a light emitting surface and a bottom surface, and the light incident surface is connected between the light emitting surface and the bottom surface;
[0088] The light source 101 is disposed on the light incident surface side of the light guide plate;
[0089] The transparent cover plate 104 is disposed on one side of the light emitting surface of the light guide plate;
[0090] The light emitting surface of the light guide plate 102 has a plurality of concave mesh structures, and a cavity is formed between the transparent cover plate and the mesh structures.
[0091] Specifically, the bottom surface of the light guide plate 102 is bonded to the ink screen 202 by optical adhesive.
[0092] In a possible implementation, the display device further includes a touch layer 201 , and the touch layer 201 is disposed on a side of the ink screen 202 away from the front light module.
[0093] The display device provided by the present disclosure has a light guide plate of a front light module with multiple mesh dot structures, wherein a cavity is formed between the mesh dot structure and the cover plate, and the cavity can allow incident light to be fully reflected, thereby increasing the amount of effective illumination light, and improving the total luminous flux, brightness and center point brightness of the front light module, thereby improving the contrast and picture quality of the display device, and by designing the light-facing angle formed by the light-facing surface of the mesh dot structure, the total luminous flux, total brightness and center point brightness of the display device are further improved, thereby further improving the brightness, contrast and picture quality of the display device.
[0094] Obviously, the above embodiments of the present disclosure are merely examples for clearly illustrating the present disclosure, and are not limitations on the implementation methods of the present disclosure. For ordinary technicians in this field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present disclosure are still within the protection scope of the present disclosure.
Claims
1. A front light module, characterized in that: The front light module includes a transparent cover plate, a light guide plate, and a light source; The light guide plate has a light incident surface, a light emitting surface and a bottom surface, and the light incident surface is connected between the light emitting surface and the bottom surface; The light source is arranged on one side of the light incident surface of the light guide plate; The transparent cover plate is arranged on one side of the light emitting surface of the light guide plate; The light emitting surface of the light guide plate has a plurality of concave mesh structures, and a cavity is formed between the transparent cover plate and the mesh structure; The lattice structure comprises a light-facing surface and a backlight surface, and a light-facing angle formed by the light-facing surface and the transparent cover plate is 35° to 42°.
2. The front light module according to claim 1, characterized in that: The backlight angle formed by the backlight surface and the transparent cover plate is 18° to 25°.
3. The front light module according to claim 1, characterized in that: The depression depth of the dot structure is 5.5 μm to 6.5 μm.
4. The front light module according to claim 1, characterized in that: The length of the mesh dot structure in a direction perpendicular to the light incident surface is 28 μm to 34 μm.
5. The front light module according to claim 1, characterized in that: The length of the mesh dot structure in a direction parallel to the light incident surface is 20 μm to 26 μm.
6. The front light module according to claim 1, characterized in that: A gap between the light source and the light incident surface of the light guide plate is less than or equal to 0.15 mm.
7. The front light module according to claim 1, characterized in that: The front light module further comprises a light shielding tape, which is arranged on a side of the light guide plate close to the cover plate, and is pasted to cover the gap between the light source and the light guide plate and to cover the light source.
8. The front light module according to claim 1, characterized in that: The front light module also includes a light shielding frame covering the light guide plate and the light source.
9. A display device, characterized in that: The front light module and ink screen according to any one of claims 1 to 8 are included, wherein: The front light module is covered on the ink screen.
10. The display device according to claim 9, characterized in that: The display device further includes a touch layer, and the touch layer is arranged on a side of the ink screen away from the front light module.