CN219552795U - Front lighting structure of electronic paper display screen - Google Patents

Abstract

A front lighting structure of electronic paper display screen comprises a surface cover plate with a viewing area and a black frame at the peripheral edge; a lighting module having a light guide plate and a point light source; the light adjusting layer is provided with a light-thinning medium area at the central part and frame-shaped glue at the peripheral edge, the refractive index of the light-thinning medium area is smaller than that of the light guide plate, the surface cover plate and the lighting module are bonded together by the frame-shaped glue of the light adjusting layer, and the light-thinning medium area is arranged on the upper surface of the light guide plate; an optical adhesive layer with refractive index equal to or greater than that of the light guide plate; the electronic paper display module is arranged on the bottom surface of the lighting module, and the electronic paper display module is attached to the bottom surface of the light guide plate by using the optical adhesive layer; by arranging the light-thinning medium region with low refractive index on the upper surface of the light guide plate, the upper surface of the light guide plate forms a total reflection interface, thereby eliminating the defect of ghost phenomenon on the display screen near the black frame part.

Description

Front lighting structure of electronic paper display screen

Technical Field

The utility model relates to the technical field of electronic paper display equipment, in particular to a front lighting structure of an electronic paper display screen with an improved structure.

Background

Electronic paper is widely used in combination with various electronic devices; the electronic paper has the characteristics of simulated paper such as flexibility, wide visual angle, light weight, high resolution, high contrast, indoor and outdoor readability and the like, and the electronic paper has the advantages of low power consumption and the like, but the electronic paper does not emit light, and is used as a source of illumination light of a display screen, and the display quality is seriously affected in the occasion of insufficient ambient light such as indoor space and the like, so that the electronic paper display equipment is mostly provided with an illumination module to provide auxiliary illumination light so as to ensure the display quality of the electronic paper. The lighting module is installed in front of the electronic paper display screen so as to provide auxiliary lighting for the electronic paper display screen.

As shown in fig. 1 and 2, the structure of the illumination module 30 is that one or more point light sources 32 are disposed on the side end surface of a light guide plate 31, and the light guide plate 31 can convert the point light sources 32 into surface light sources, so that light is uniformly projected onto the display screen of the electronic paper display module 50 to provide illumination; the illumination module 30 is disposed between the surface cover plate 10 and the lamination layers of the electronic paper display module 50, and the lamination layers are bonded into a whole by using the optical adhesive layer 40; wherein, a black frame 12 is provided as a decorative frame covering the edge circuit structure, and a point light source 32 of the lighting module is located just below the black frame 12.

However, such a conventional illumination structure disposed in front of the electronic paper display screen often generates a ghost phenomenon of uneven brightness on the display screen near the black frame 12, which affects the prospective of the electronic paper display screen; the reason for this is outlined as follows: the refractive indexes of the materials of the optical adhesive layer 40 and the light guide plate 31 are approximately between 1.47 and 1.51, and the refractive indexes of the two materials are similar, so that the optical adhesive layer 40 can destroy the total reflection effect of the surface of the light guide plate 31 after being bonded together, and therefore, part of the light of the point-shaped light source 32 incident from the side surface of the light guide plate 31 is refracted to the optical adhesive layer 40 and the surface cover plate 10, the refracted light can be influenced by the black frame 12, and the light and shade lines SD with uneven brightness are formed on the display screen near the black frame 12, thereby seriously affecting the appearance and reducing the look of the electronic paper display screen, and the reality is to be improved.

Disclosure of Invention

In view of the defect of the conventional illumination structure configured in front of the electronic paper display screen, the main object of the present utility model is to provide an improved front illumination structure of the electronic paper display screen, which can eliminate the defect of the ghost phenomenon generated on the display screen near the black frame part, so that the illumination of the electronic paper display device can achieve a uniform and bright effect.

In order to achieve the above-mentioned objective, the present utility model provides a front lighting structure of an electronic paper display screen, which comprises a surface cover plate, wherein the central portion is a prospective region, and a black frame formed by opaque or low light transmittance materials is arranged at the peripheral edge region of the bottom surface; the lighting module is provided with a light guide plate and a plurality of point-shaped light sources, and the point-shaped light sources are arranged at the outer side edge part of the light guide plate; the light adjusting layer is provided with a light-thinning medium area at the central part and frame-shaped glue at the peripheral edge area, the area of the light-thinning medium area is equal to or larger than that of the prospective area, the refractive index of the light-thinning medium area is smaller than that of the light guide plate, the frame-shaped glue has a size specification corresponding to that of the black frame, the surface cover plate and the lighting module are bonded together through the frame-shaped glue of the light adjusting layer, and the light-thinning medium area is arranged on the upper surface of the light guide plate; an optical adhesive layer with refractive index equal to or greater than that of the light guide plate; the electronic paper display module is arranged on the bottom surface of the lighting module, and the optical adhesive layer is used for attaching the electronic paper display module to the bottom surface of the light guide plate; by arranging the light and hydrophobic medium region with low refractive index on the upper surface of the light guide plate, the upper surface of the light guide plate forms a total reflection interface, thereby eliminating the defect of ghost phenomenon on the display screen near the black frame part.

According to the utility model, the refractive index of the photophobic medium region is close to 1; preferably, the photophobic medium region is an air layer or a hollow layer.

In an embodiment, the photophobic medium region is a transparent resin layer with a refractive index less than 1.40.

According to the utility model, the difference in size between the inner edge of the frame-shaped glue and the inner edge of the black frame is more than 500 um.

According to the utility model, the frame type glue is made of one of OCA optical glue, OCR optical glue, SCA optical glue and opaque double-sided glue.

According to the utility model, the material of the optical adhesive layer is selected from one of OCA optical adhesive, OCR optical adhesive or SCA optical adhesive.

Additional features and advantages of the utility model will be set forth in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following.

Drawings

Fig. 1 is a schematic plan view of a conventional electronic paper display.

FIG. 2 is a schematic side sectional view of the laminated composite structure of FIG. 1 along section line II-II.

FIG. 3 is a schematic side cross-sectional view of the laminated composite structure of the present utility model.

Fig. 4 is a schematic view of a component separator of the laminated composite structure of the present utility model.

Symbol description in the drawings:

10 a surface cover plate;

11 a prospective zone;

12 black frames;

12a inner edge of the black frame;

20 a light conditioning layer;

a light thinning medium region 21;

22 frame type glue;

22a inner edge of the frame glue;

a lighting module 30;

31 a light guide plate;

32 point light sources;

40 an optical cement layer;

50 an electronic paper display module;

51 visual area;

SD shadow lines;

Δd size difference.

Detailed Description

Fig. 3 and 4 show a preferred embodiment of the present utility model, which comprises, in order, a surface cover plate 10, a light adjusting layer 20, an illumination module 30, an optical adhesive layer 40, and an electronic paper display module 50, wherein:

the surface cover plate 10 uses a thin plate having high light transmittance with excellent mechanical strength, and the material thereof is selected from various glasses, polymethyl methacrylate (PMMA), polycarbonate (PC), polyester (PET), cyclic Olefin Copolymer (COC), cyclic Olefin Polymer (COP), etc., but the implementation range is not limited to the foregoing materials. Wherein, the central part of the surface cover plate 10 is a transparent prospective region 11, and the peripheral edge region of the bottom surface is provided with a black frame 12, the black frame 12 is an opaque or low-transmittance film layer made of a non-conductive material, and the non-conductive material can be selected from ink or photoresist (photo mask), but the applicable material range is not limited thereto; the non-conductive material may be formed into a thin film layer having a thickness of 15 μm or more on the peripheral portion of the bottom surface of the surface cover plate 10 by printing, sputtering, coating, or the like. The black frame 12 of the surface cover plate can shield the dot light sources 32 and the peripheral circuit area of the electronic paper display module 50 at the edge of the illumination module 30 below, so as to improve the aesthetic property of the whole device.

The illumination module 30 comprises a light guide plate 31, and at least one point light source 32 is disposed at an outer side edge of the light guide plate 31, wherein the point light source 32 can be an LED or a Mico LED; the point light source 32 projects light from one end face of the light guide plate 31, and converts the projected light into a surface light source that emits downward. The area of the light guide plate 31 is matched with the visible area 51 of the electronic paper display module 50, which will be described later, so as to provide good light illumination for the visible area 51. The material of the light guide plate 31 is selected from Polycarbonate (PC), polymethyl methacrylate (PMMA), and Polyester (PET), but the kind of the material is not limited thereto. In order to form a surface light source with uniformly distributed light brightness on the light guide plate 31, a plurality of light scattering points (not shown in the figure) may be disposed on the plate body of the light guide plate 31 to convert the incident light from the point light source 32 into light uniformly distributed on the plate body; wherein, the light-emitting points can be selected from materials with refractive index higher than that of the substrate of the light guide plate 31, or the concave holes or protruding bumps can be arranged on the plate body of the light guide plate 31, and the light-emitting points are distributed on the light guide plate 31 in a sparse and dense manner so as to achieve the effect of uniform light brightness distribution on the light guide plate 31.

The light conditioning layer 20 is arranged between the aforementioned surface cover plate 10 and the lighting module 30; the central part of the light regulating layer 20 is an optical-hydrophobic medium area 21 with low refractive index, and a frame type glue 22 is arranged at the peripheral edge area; wherein the area of the photo-thinning medium region 21 is equal to or slightly larger than the area of the prospective region 11 of the surface cover plate, and the refractive index of the photo-thinning medium region 21 is smaller than the refractive index of the light guide plate 31, preferably, the photo-thinning medium region 21 is an air layer or a vacuum layer with the refractive index approaching 1; in other possible embodiments, when the light guide plate 31 is made of PMMA with a refractive index of 1.491, the optically-sparse medium region 21 may be made of a transparent resin with a refractive index of 1.40 or less, for example, 1.375Acrylic #18204. In addition, the frame glue 22 has a size corresponding to the black frame 12 of the surface cover plate, preferably, the difference Δd between the inner edge 22a of the frame glue and the inner edge 12a of the black frame is 500um or more to reduce the addition ofThe working accuracy and the technical difficulty are simplified; the frame-type adhesive 22 can be made of various adhesives, such as OCA (Optical Clear Adhesive), OCR (Optical ClearResin), SCA (Solid Optically Clear Adhesive) or opaque double-sided adhesive, but the applicable range is not limited thereto.

The optical adhesive layer 40 may be a commercially available optically transparent adhesive such as OCA optical adhesive, OCR optical adhesive or SCA optical adhesive; wherein the refractive index of the optical adhesive layer 40 is equal to or greater than the refractive index of the light guide plate 31.

The electronic paper display module 50 is a reflective display with low power consumption and flexibility, and uses electrophoresis technology or cholesterol liquid crystal technology to display the image signal on the display screen (i.e. the visual area 51) of the electronic paper display module 50 as an image frame.

As shown in fig. 3 and 4, the surface cover plate 10 and the lighting module 30 are adhered together by the frame glue 22 of the light adjusting layer, and the light-shielding medium area 21 of the light adjusting layer is disposed on the upper surface of the light guide plate 31, wherein the refractive index of the light-shielding medium area 21 is smaller than that of the light guide plate 31, so that a total reflection interface is formed on the upper surface of the light guide plate 31, and the light incident into the light guide plate 31 from the side surface is not refracted upwards any more and is adversely affected by the black frame 12, thereby improving the problem of ghost phenomenon on the display screen near the black frame. In addition, the optical adhesive layer 40 is attached to the bottom surface of the light guide plate 31 of the lighting module, wherein the refractive index of the optical adhesive layer 40 is equal to or greater than the refractive index of the light guide plate 31, so that the light in the light guide plate 31 can smoothly pass through the bottom surface of the light guide plate 31 and the optical adhesive layer 40 to be projected onto the visual area 51 of the electronic paper display module 50 to provide good lighting.

Although the utility model has been fully described with reference to the accompanying drawings in connection with the specific embodiments, it is to be understood that the foregoing embodiments are merely illustrative examples for further description and that the embodiments of the utility model are not limited thereto, but are to be construed as included within the scope of the utility model as defined by the appended claims.

Claims (7)

1. A front lighting structure of an electronic paper display screen, comprising:

a surface cover plate, the central part of which is a prospective zone, and the peripheral edge area of the bottom surface of which is provided with a black frame formed by opaque or low light transmittance materials;

the lighting module is provided with a light guide plate and a plurality of point-shaped light sources, and the point-shaped light sources are arranged at the outer side edge part of the light guide plate;

the light adjusting layer is provided with a light-thinning medium area at the central part and frame-shaped glue at the peripheral edge area, the area of the light-thinning medium area is equal to or larger than that of the prospective area, the refractive index of the light-thinning medium area is smaller than that of the light guide plate, the frame-shaped glue has a size specification corresponding to that of the black frame, the surface cover plate and the lighting module are bonded together through the frame-shaped glue of the light adjusting layer, and the light-thinning medium area is arranged on the upper surface of the light guide plate;

an optical adhesive layer with refractive index equal to or greater than that of the light guide plate; and

and the electronic paper display module is arranged on the bottom surface of the lighting module, and the optical adhesive layer is used for attaching the electronic paper display module to the bottom surface of the light guide plate.

2. The front lighting structure of electronic paper display screen of claim 1, wherein the refractive index of the optically hydrophobic medium region is approximately 1.

3. The front lighting structure of electronic paper display screen according to claim 2, wherein the light-sparse medium area is an air layer or a hollow layer.

4. The front lighting structure of electronic paper display screen of claim 1, wherein the light-sparse medium region is a transparent resin layer having a refractive index of less than 1.40.

5. The front lighting structure of electronic paper display screen according to claim 1, wherein a size difference between an inner edge of the frame glue and an inner edge of the black frame is 500um or more.

6. The front lighting structure of electronic paper display screen according to claim 1, wherein the frame glue is made of one of OCA optical glue, OCR optical glue, SCA optical glue and opaque double-sided glue.

7. The front lighting structure of electronic paper display screen according to claim 1, wherein the material of the optical adhesive layer is selected from one of OCA optical adhesive, OCR optical adhesive and SCA optical adhesive.