A cholesteric liquid crystal display device

Abstract

The utility model discloses a kind of cholesteric liquid crystal display devices, lower substrate is equipped with multiple gate lines extending along first direction and multiple source lines extending along second direction in liquid crystal layer side, and pixel array formed by multiple pixel units is formed by multiple gate lines and multiple source lines, each pixel unit includes display area and non-display area, upper substrate is equipped with light absorption layer in liquid crystal layer side away, and light absorption layer includes opening area corresponding with the display area of pixel unit and light absorption area corresponding with non-display area. By setting light absorption layer corresponding with the non-display area of pixel unit on the outer surface of upper substrate, so that the light of incident non-display area is absorbed by light absorption layer, reduce the surface reflectivity of display device, improve the color saturation and contrast of cholesteric liquid crystal display, to effectively improve the display effect of product.

Description

Technical Field

[0001] This utility model relates to the field of cholesteric liquid crystal display technology, and in particular to a cholesteric liquid crystal display device. Background Technology

[0002] Reflective liquid crystal displays (LCDs) do not require a backlight module to provide a light source, thus offering advantages such as thinness and low power consumption. They are used in various electronic products where ambient light is present, such as electronic paper. Electronic paper is categorized into electrophoretic electronic paper, cholesteric liquid crystal electronic paper, and toner electronic paper. Among these, cholesteric liquid crystal electronic paper relies on a twisted cholesteric liquid crystal layer to reflect light of a specific wavelength and utilizes the bistable property of cholesteric liquid crystals to maintain the image even after power is off.

[0003] A typical single-layer cholesteric display device structure includes upper and lower substrates and a liquid crystal layer between them. The inner surface of the upper glass substrate contains a black light-shielding layer, a common electrode, and corresponding support structures. The inner surface of the lower glass substrate contains gate drive lines, signal lines, an insulating layer between metals, pixel electrodes, and transistor switches that control individual pixels. The outer surface of the lower glass substrate is coated with a black ink layer. A single pixel in the display device comprises two regions: an aperture area and a non-display area. The films in the aperture area are transparent, allowing light to pass through, while the reflected light from the liquid crystal can exit normally. The non-display area mainly consists of metal lines and transistor switches. To prevent their reflected light from affecting the reflection effect of the aperture area, a black light-shielding layer is typically formed on the inner surface of the upper glass substrate. This black light-shielding layer covers the metal trace areas on the glass substrate, preventing metal reflection; no liquid crystal reflected light exits from this area.

[0004] However, during the display process, the cholesteric liquid crystal is in the P-state. When external light is incident on the display device, in addition to the reflected light generated by the cholesteric liquid crystal layer, surface reflection occurs on the surface of the upper glass substrate due to the difference in refractive index between the upper glass substrate and the air layer. This reflected light covers the entire visible light band from 380 to 780 nm, with a reflectivity typically around 5%. The color saturation decreases due to the influence of this surface reflection. Furthermore, when the cholesteric liquid crystal is in the FC-state, external light is scattered upon impact with the display device. Most of the incident light is ultimately absorbed by the underlying black ink layer, resulting in a dark state. However, surface reflection still occurs on the upper glass substrate surface. The reflectivity of the display device in the FC-state increases, leading to a decrease in contrast and affecting the display effect. Utility Model Content

[0005] To address the technical problems existing in the background art, this utility model proposes a cholesteric liquid crystal display device.

[0006] This utility model proposes a cholesteric liquid crystal display device, comprising: an upper substrate, a lower substrate, and a liquid crystal layer sandwiched between the two.

[0007] The lower substrate has a plurality of gate lines extending in a first direction and a plurality of source lines extending in a second direction on the side near the liquid crystal layer. A pixel array formed by a plurality of pixel units is formed by the plurality of gate lines and the plurality of source lines. Each pixel unit includes a display area and a non-display area. The upper substrate has a light absorption layer on the side away from the liquid crystal layer. The light absorption layer includes an opening area corresponding to the display area of ​​the pixel unit and a light absorption area corresponding to the non-display area.

[0008] Preferably, the upper substrate is further provided with a light-shielding layer on the side near the liquid crystal layer, and the light-shielding layer includes a light-shielding area corresponding to the non-display area of ​​the pixel unit.

[0009] Preferably, the light-shielding area and the non-display area are the same size.

[0010] Preferably, the light absorption region and the opening region of the light absorption layer form a mesh structure.

[0011] Preferably, an antireflection layer is also provided on the side of the upper substrate away from the liquid crystal layer.

[0012] Preferably, the light absorption layer is disposed on the side of the antireflection layer away from the upper substrate.

[0013] Preferably, the light-absorbing area is made of black ink or black photoresist.

[0014] The present invention proposes a cholesteric liquid crystal display device, comprising multiple stacked display modules and a light absorption layer, wherein each display module comprises an upper substrate, a lower substrate and a liquid crystal layer sandwiched between the two.

[0015] The lower substrate has multiple gate lines extending along a first direction and multiple source lines extending along a second direction on the side near the liquid crystal layer. A pixel array formed by multiple pixel units is formed by the multiple gate lines and multiple source lines. Each pixel unit includes a display area and a non-display area. The pixel units of multiple display modules are vertically aligned.

[0016] The light absorption layer is located on the upper substrate of the top display module. The light absorption layer includes an opening area corresponding to the display area of ​​the pixel unit and a light absorption area corresponding to the non-display area.

[0017] In this invention, the proposed cholesteric liquid crystal display device has a lower substrate with multiple gate lines extending along a first direction and multiple source lines extending along a second direction on the side near the liquid crystal layer. These gate lines and source lines form a pixel array composed of multiple pixel units, each pixel unit including a display area and a non-display area. An upper substrate has a light-absorbing layer on the side away from the liquid crystal layer. This light-absorbing layer includes an opening area corresponding to the display area of ​​the pixel unit and a light-absorbing area corresponding to the non-display area. By providing a light-absorbing layer corresponding to the non-display area of ​​the pixel unit on the outer surface of the upper substrate, light incident on the non-display area is absorbed by the light-absorbing layer, reducing the surface reflectivity of the display device and improving the color saturation and contrast of the cholesteric liquid crystal display, thereby effectively improving the product's display performance. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a prior art cholesteric liquid crystal display device.

[0019] Figure 2 This is a schematic diagram of the gate and source arrangement on the lower substrate in the prior art.

[0020] Figure 3 This is a schematic diagram of one embodiment of the cholesteric liquid crystal display device proposed in this utility model.

[0021] Figure 4 This is a schematic diagram of the light absorption layer in one embodiment of the cholesteric liquid crystal display device proposed in this utility model.

[0022] Figure 5 This is a schematic diagram of another embodiment of the cholesteric liquid crystal display device proposed in this utility model.

[0023] Figure 6 This is a schematic diagram of another embodiment of the cholesteric liquid crystal display device proposed in this utility model.

[0024] Figure 7 This is a schematic diagram of another embodiment of the cholesteric liquid crystal display device proposed in this utility model. Detailed Implementation

[0025] Reference Figures 2 to 4 The present invention proposes a cholesteric liquid crystal display device, comprising an upper substrate 1, a lower substrate 2, and a liquid crystal layer 3 sandwiched between the two.

[0026] The lower substrate 2 has a plurality of gate lines 4 extending in a first direction and a plurality of source lines 5 extending in a second direction on the side near the liquid crystal layer 3. A pixel array formed by a plurality of pixel units is formed by the plurality of gate lines 4 and the plurality of source lines 5. Each pixel unit includes a display area and a non-display area. The upper substrate 1 has a light absorption layer 6 on the side away from the liquid crystal layer 3. The light absorption layer 6 includes an opening area 61 corresponding to the display area of ​​the pixel unit and a light absorption area 62 corresponding to the non-display area.

[0027] During display, a single pixel in a display device comprises two areas: an aperture area and a light-blocking area. Within the aperture area, each film layer is made of transparent material, allowing light to pass through. During display, the liquid crystal in some pixel units is in the P-state, allowing light to be reflected and emitted normally, while the liquid crystal in other pixel units is in the FC-state, allowing light to pass through. The light-absorbing area of ​​the light-absorbing layer covers the non-display area of ​​the pixel unit from the outside of the upper substrate, preventing reflections from the metal traces of the pixel unit and thus completely eliminating the reflective effects of the non-display area of ​​the pixel unit and its corresponding light-incident area on the upper substrate.

[0028] In this embodiment, the proposed cholesteric liquid crystal display device has a lower substrate with multiple gate lines extending along a first direction and multiple source lines extending along a second direction on the side near the liquid crystal layer. These gate lines and source lines form a pixel array composed of multiple pixel units, each pixel unit including a display area and a non-display area. An upper substrate with a light-absorbing layer on the side away from the liquid crystal layer includes an opening area corresponding to the display area of ​​the pixel unit and a light-absorbing area corresponding to the non-display area. By providing a light-absorbing layer corresponding to the non-display area of ​​the pixel unit on the outer surface of the upper substrate, light incident on the non-display area is absorbed by the light-absorbing layer, reducing the surface reflectivity of the display device and improving the color saturation and contrast of the cholesteric liquid crystal display, thereby effectively improving the product's display performance.

[0029] In the specific design of the light absorption layer, the light absorption area 62 uses black ink or black photoresist to ensure the light absorption effect on the incident non-display area. In actual operation, other light-absorbing materials can also be used for the light absorption layer.

[0030] like Figure 4 As shown, in one specific embodiment, a light-absorbing layer may be provided only on the top of the upper substrate. The light-absorbing region 62 and the opening region 61 of the light-absorbing layer 6 form a mesh structure corresponding to the pixel array. When incident light is incident on the surface of the display device, the light in the opening region is reflected normally, while the incident light in the light-absorbing region is absorbed and no reflection occurs; thereby reducing the surface reflectivity of the device and improving the color saturation and contrast of the display device.

[0031] In the specific design of the size of the light absorption region, the surface reflectivity ratio R% = S 光吸收区 / S 单个像素 *100%, of which S 光吸收区 S represents the area occupied by the light absorption region in a single pixel. 单个像素 The area occupied by a single pixel.

[0032] like Figure 5 As shown, in another specific embodiment, a light-shielding layer 7 can also be provided on the side of the upper substrate 1 near the liquid crystal layer 3. The light-shielding layer 7 includes a light-shielding area corresponding to the non-display area of ​​the pixel unit. By further shielding the non-display area through the light-shielding area, the influence of scattered light from the non-display area on the display is further reduced.

[0033] In the specific design of the light-shielding area, the light-shielding area can correspond one-to-one with the non-display area and have the same size, so as not to affect the liquid crystal reflected light of the display area.

[0034] Furthermore, in the opening region of the light-absorbing layer at the top of the upper substrate, the refractive index of the interface between the air and the upper substrate is relatively high, which reduces the light incident efficiency of the liquid crystal display area. Therefore, as Figure 6 As shown, in other specific embodiments, an antireflection layer 8 is also provided on the side of the upper substrate 1 away from the liquid crystal layer 3. Further, a light absorption layer 6 is disposed on the side of the antireflection layer 8 away from the upper substrate 1. By first providing an antireflection layer on the outer surface of the upper substrate, and by optimizing the refractive index of the antireflection layer, the reflectivity of the upper glass surface can be reduced. By then providing a light absorption layer above the antireflection layer, the surface reflectivity of the device can be further reduced.

[0035] In practical antireflection layer design, the antireflection layer typically comprises at least two layers, with refractive indices between those of air and the upper substrate, and these refractive indices differ from those of the upper substrate. The refractive indices at the interfaces between air and layer, layer and layer, and layer and substrate are all lower than the refractive index at the air-substrate interface. This reduces the reflectivity of effectively incident light in the opening region when incident light enters the antireflection layer, further improving the color saturation and contrast of the cholesteric liquid crystal display.

[0036] Reference Figure 7 This embodiment also proposes a cholesteric liquid crystal display device, including multiple stacked display modules and a light absorption layer. Each display module includes an upper substrate 1, a lower substrate 2 and a liquid crystal layer 3 sandwiched between the two.

[0037] The lower substrate 2 has a plurality of gate lines 4 extending in a first direction and a plurality of source lines 5 extending in a second direction on the side near the liquid crystal layer 3. A pixel array formed by a plurality of pixel units is formed by the plurality of gate lines 4 and the plurality of source lines 5. Each pixel unit includes a display area and a non-display area. The pixel units of the plurality of display modules are vertically aligned.

[0038] The light absorption layer 6 is located on the upper substrate 1 of the top display module. The light absorption layer 6 includes an opening area 61 corresponding to the display area of ​​the pixel unit and a light absorption area 62 corresponding to the non-display area.

[0039] To achieve multi-color display, multiple display modules can be stacked and arranged in layers. The pixel units of different display modules correspond vertically. Only a light absorption layer needs to be set on the top of the uppermost display module to block the non-display areas of all display modules.

[0040] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A cholesteric liquid crystal display device, characterized in that, include: Upper substrate (1), lower substrate (2) and liquid crystal layer (3) sandwiched between the two; The lower substrate (2) is provided with a plurality of gate lines (4) extending in a first direction and a plurality of source lines (5) extending in a second direction on the side near the liquid crystal layer (3), and a pixel array formed by a plurality of pixel units is formed by the plurality of gate lines (4) and the plurality of source lines (5). Each pixel unit includes a display area and a non-display area. A light absorption layer (6) is provided on the side of the upper substrate (1) away from the liquid crystal layer (3). The light absorption layer (6) includes an opening area (61) corresponding to the display area of ​​the pixel unit and a light absorption area (62) corresponding to the non-display area.

2. The cholesteric liquid crystal display device according to claim 1, characterized in that, The upper substrate (1) is also provided with a light-shielding layer (7) on the side near the liquid crystal layer (3), and the light-shielding layer (7) includes a light-shielding area corresponding to the non-display area of ​​the pixel unit.

3. The cholesteric liquid crystal display device according to claim 2, characterized in that, The light-blocking area is the same size as the non-display area.

4. The cholesteric liquid crystal display device according to claim 1, characterized in that, The light absorption region (62) and the opening region (61) of the light absorption layer (6) form a mesh structure.

5. The cholesteric liquid crystal display device according to claim 1, characterized in that, An antireflection layer (8) is also provided on the side of the upper substrate (1) away from the liquid crystal layer (3).

6. The cholesteric liquid crystal display device according to claim 5, characterized in that, The light absorption layer (6) is disposed on the side of the antireflection layer (8) away from the upper substrate (1).

7. The cholesteric liquid crystal display device according to claim 1, characterized in that, The light absorption area (62) is made of black ink or black photoresist.

8. A cholesteric liquid crystal display device, characterized in that, It includes multiple stacked display modules and light absorption layers. Each display module includes an upper substrate (1), a lower substrate (2), and a liquid crystal layer (3) sandwiched between the two. The lower substrate (2) is provided with a plurality of gate lines (4) extending along a first direction and a plurality of source lines (5) extending along a second direction on the side near the liquid crystal layer (3). A pixel array formed by a plurality of pixel units is formed by the plurality of gate lines (4) and the plurality of source lines (5). Each pixel unit includes a display area and a non-display area. The pixel units of the plurality of display modules are vertically aligned. The light absorption layer (6) is located on the upper substrate (1) of the top display module. The light absorption layer (6) includes an opening area (61) corresponding to the display area of ​​the pixel unit and a light absorption area (62) corresponding to the non-display area.

Images