CN-122018195-A - Reflective display device and driving method

CN122018195ACN 122018195 ACN122018195 ACN 122018195ACN-122018195-A

Abstract

The invention discloses a reflective display device and a driving method, wherein the reflective display device comprises a first liquid crystal box and a second liquid crystal box which is laminated on the light emitting side of the first liquid crystal box, second cholesteric liquid crystal molecules of the second liquid crystal box reflect first color light rays in a reflective state, first cholesteric liquid crystal molecules of the first liquid crystal box reflect complementary color light rays of the first color light rays in the reflective state, a second color resistance layer and a third color resistance layer are arranged on the reflective display device, projections of the second color resistance layer and the third color resistance layer on the reflective display device are completely staggered, at least one of the projections is arranged on a first opposite substrate, and the filtering wavelength of the second color resistance layer and the filtering wavelength of the third color resistance layer are partially overlapped with the wavelength of the complementary color light rays. Therefore, the reflective display device can realize color display by adopting the double liquid crystal boxes, the colors are richer, the box thickness is smaller, the display of three primary colors can be realized by only two sub-pixels, and the aperture opening ratio is larger.

Inventors

ZHONG DEZHEN
ZHENG HUILONG
JIANG JUAN
WANG XINGANG
ZHOU XUEQIN

Assignees

昆山龙腾光电股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260323

Claims (10)

1. A reflective display device, comprising a first liquid crystal cell (10) and a second liquid crystal cell (20) stacked on a light emitting side of the first liquid crystal cell (10), wherein the first liquid crystal cell (10) has a plurality of first pixel units (P1) distributed in an array, the second liquid crystal cell (20) has a plurality of second pixel units (P2) distributed in an array, and each second pixel unit (P2) corresponds to at least one first pixel unit (P1); The first liquid crystal cell (10) comprises a first opposite substrate (11), a first array substrate (12) arranged opposite to the first opposite substrate (11) and a first cholesteric liquid crystal layer (13) arranged between the first opposite substrate (11) and the first array substrate (12), the first opposite substrate (11) is arranged on one side of the first liquid crystal cell (10) facing the second liquid crystal cell (20), the first cholesteric liquid crystal layer (13) comprises first cholesteric liquid crystal molecules (131), the first cholesteric liquid crystal molecules (131) reflect light rays with the same color in a reflection state, a first pixel electrode (121) corresponding to the first pixel unit (P1) is arranged on the first array substrate (12), and a first common electrode (111) matched with the first pixel electrode (121) is arranged on the first opposite substrate (11); The second liquid crystal box (20) comprises a second opposite substrate (21), a second array substrate (22) arranged opposite to the second opposite substrate (21) and a second cholesteric liquid crystal layer (23) arranged between the second opposite substrate (21) and the second array substrate (22), the second cholesteric liquid crystal layer (23) comprises second cholesteric liquid crystal molecules (231), the second cholesteric liquid crystal molecules (231) reflect light rays with the same color in a reflection state, a second pixel electrode (221) corresponding to the second pixel unit (P2) is arranged on the second array substrate (22), and a second common electrode (211) matched with the second pixel electrode (212) is arranged on the second opposite substrate (21); The second cholesteric liquid crystal molecules (231) reflect first color light rays in a reflection state, the first cholesteric liquid crystal molecules (131) reflect complementary color light rays of the first color light rays in the reflection state, the reflective display device is provided with a second color resistance layer (113 a) and a third color resistance layer (113 b), projections of the second color resistance layer (113 a) and the third color resistance layer (113 b) on the reflective display device are completely staggered, at least one of the projections is arranged on the first opposite substrate (11), and the filtering wavelength of the second color resistance layer (113 a) and the filtering wavelength of the third color resistance layer (113 b) are partially overlapped with the wavelength of the complementary color light rays.
2. The reflective display device according to claim 1, wherein each of the second pixel units (P2) corresponds to two different first pixel units (P1), the second color resist layer (113 a) and the third color resist layer (113 b) are disposed on the first opposite substrate (11) and each correspond to a different first pixel unit (P1), and the second opposite substrate (21) is in a transparent state in a region corresponding to the second pixel unit (P2).
3. The reflective display device according to claim 1, wherein the first pixel units (P1) are in one-to-one correspondence with the second pixel units (P2), the second counter substrate (21) is located at a side of the second liquid crystal cell (20) away from the first liquid crystal cell (10), the third color resist layer (113 b) is disposed on the first counter substrate (11), the second color resist layer (113 a) is disposed on the second counter substrate (21), the first counter substrate (11) is in a transparent state in a region corresponding to the second color resist layer (113 a), and the second counter substrate (21) is in a transparent state in a region corresponding to the third color resist layer (113 b).
4. The reflective display device according to claim 1, wherein the first pixel units (P1) are in one-to-one correspondence with the second pixel units (P2), the second counter substrate (21) is located at a side of the second liquid crystal cell (20) away from the first liquid crystal cell (10), the second color resist layer (113 a) is disposed on the first counter substrate (11), the third color resist layer (113 b) is disposed on the second counter substrate (21), the first counter substrate (11) is in a transparent state in a region corresponding to the third color resist layer (113 b), and the second counter substrate (21) is in a transparent state in a region corresponding to the second color resist layer (113 a).
5. The reflective display device of any one of claims 1-4, wherein the first color is blue, one of the second color and the third color is red, and the other is green; Or, the first color is red, one of the second color and the third color is blue, and the other is green; or, the first color is green, one of the second color and the third color is red, and the other is blue.
6. The reflective display device according to any of claims 1-4, characterized in that the reflective display device comprises an entirely arranged light absorbing layer (30), which light absorbing layer (30) is arranged at a side of the first liquid crystal cell (10) remote from the second liquid crystal cell (20) and is arranged to absorb light rays passing through the first liquid crystal cell (10) and the second liquid crystal cell (20).
7. A reflective display device according to any one of claims 1-4, wherein a first black matrix (112) is provided on the first counter substrate (11), the first black matrix (112) being adapted to space a plurality of the first pixel units (P1) apart from each other; the second counter substrate (21) is provided with a second black matrix (212), and the second black matrix (212) is used for mutually spacing a plurality of second pixel units (P2).
8. A driving method of a reflective display device according to claim 2, characterized in that the driving method comprises: When a first color is displayed, controlling the second cholesteric liquid crystal molecules (231) in the corresponding area of the second pixel unit (P2) to be in a reflection state and the first cholesteric liquid crystal molecules (131) in the corresponding area to be in a transparent state or a fog state, wherein the second pixel unit (P2) reflects light rays of the first color; When a second color is displayed, controlling the second cholesteric liquid crystal molecules (231) in the corresponding area of the second pixel unit (P2) to be in a transparent state or a fog state, controlling the first cholesteric liquid crystal molecules (131) in the corresponding area of the second color resistance layer (113 a) to be in a reflective state, and controlling the first cholesteric liquid crystal molecules (131) in the corresponding area of the third color resistance layer (113 b) to be in a transparent state or a fog state, wherein the first pixel unit (P1) in the corresponding area of the second color resistance layer (113 a) reflects light of the second color; when a third color is displayed, controlling the second cholesteric liquid crystal molecules (231) in the corresponding area of the second pixel unit (P2) to be in a transparent state or a fog state, controlling the first cholesteric liquid crystal molecules (131) in the corresponding area of the third color resistance layer (113 b) to be in a reflection state, and controlling the first cholesteric liquid crystal molecules (131) in the corresponding area of the second color resistance layer (113 a) to be in a transparent state or a fog state, wherein the first pixel unit (P1) in the corresponding area of the third color resistance layer (113 b) reflects light of the third color; In the dark state, the second cholesteric liquid crystal molecules (231) in the corresponding region of the second pixel unit (P2) are controlled to be in a transparent state or a fog state, and the first cholesteric liquid crystal molecules (131) in the corresponding region of the first pixel unit (P1) are controlled to be in a transparent state or a fog state, at this time, light directly passes through the first cholesteric liquid crystal layer (13) and the second cholesteric liquid crystal layer (23).
9. A driving method of a reflective display device according to claim 3, characterized in that the driving method comprises: When a first color is displayed, controlling the first cholesteric liquid crystal molecules (131) and the second cholesteric liquid crystal molecules (231) of the corresponding area of the second color resistance layer (113 a) to be in a transparent state or a fog state, controlling the second cholesteric liquid crystal molecules (231) of the corresponding area of the third color resistance layer (113 b) to be in a reflection state, and controlling the first cholesteric liquid crystal molecules (131) of the corresponding area of the third color resistance layer (113 b) to be in a transparent state or a fog state, wherein at the moment, the second pixel units (P2) corresponding to the third color resistance layer (113 b) reflect light rays of the first color; When a second color is displayed, controlling the second cholesteric liquid crystal molecules (231) in the corresponding area of the second pixel unit (P2) to be in a transparent state or a fog state, controlling the first cholesteric liquid crystal molecules (131) in the corresponding area of the second color resistance layer (113 a) to be in a reflective state, and controlling the first cholesteric liquid crystal molecules (131) in the corresponding area of the third color resistance layer (113 b) to be in a transparent state or a fog state, wherein the first pixel unit (P1) in the corresponding area of the second color resistance layer (113 a) reflects light of the second color; when a third color is displayed, controlling the second cholesteric liquid crystal molecules (231) in the corresponding area of the second pixel unit (P2) to be in a transparent state or a fog state, controlling the first cholesteric liquid crystal molecules (131) in the corresponding area of the third color resistance layer (113 b) to be in a reflection state, and controlling the first cholesteric liquid crystal molecules (131) in the corresponding area of the second color resistance layer (113 a) to be in a transparent state or a fog state, wherein the first pixel unit (P1) in the corresponding area of the third color resistance layer (113 b) reflects light of the third color; In the dark state, the second cholesteric liquid crystal molecules (231) in the corresponding region of the second pixel unit (P2) are controlled to be in a transparent state or a fog state, and the first cholesteric liquid crystal molecules (131) in the corresponding region of the first pixel unit (P1) are controlled to be in a transparent state or a fog state, at this time, light directly passes through the first cholesteric liquid crystal layer (13) and the second cholesteric liquid crystal layer (23).
10. A driving method of a reflective display device according to claim 4, characterized by being used for driving the reflective display device, the driving method comprising: When a first color is displayed, controlling the first cholesteric liquid crystal molecules (131) and the second cholesteric liquid crystal molecules (231) of the corresponding areas of the third color resistance layer (113 b) to be in a transparent state or a fog state, controlling the second cholesteric liquid crystal molecules (231) of the corresponding areas of the second color resistance layer (113 a) to be in a reflection state, and controlling the first cholesteric liquid crystal molecules (131) of the corresponding areas of the second color resistance layer (113 a) to be in a transparent state or a fog state, wherein at the moment, the second pixel units (P2) corresponding to the second color resistance layer (113 a) reflect light rays of the first color; When a second color is displayed, controlling the second cholesteric liquid crystal molecules (231) in the corresponding area of the second pixel unit (P2) to be in a transparent state or a fog state, controlling the first cholesteric liquid crystal molecules (131) in the corresponding area of the second color resistance layer (113 a) to be in a reflective state, and controlling the first cholesteric liquid crystal molecules (131) in the corresponding area of the third color resistance layer (113 b) to be in a transparent state or a fog state, wherein the first pixel unit (P1) in the corresponding area of the second color resistance layer (113 a) reflects light of the second color; when a third color is displayed, controlling the second cholesteric liquid crystal molecules (231) in the corresponding area of the second pixel unit (P2) to be in a transparent state or a fog state, controlling the first cholesteric liquid crystal molecules (131) in the corresponding area of the third color resistance layer (113 b) to be in a reflection state, and controlling the first cholesteric liquid crystal molecules (131) in the corresponding area of the second color resistance layer (113 a) to be in a transparent state or a fog state, wherein the first pixel unit (P1) in the corresponding area of the third color resistance layer (113 b) reflects light of the third color; In the dark state, the second cholesteric liquid crystal molecules (231) in the corresponding region of the second pixel unit (P2) are controlled to be in a transparent state or a fog state, and the first cholesteric liquid crystal molecules (131) in the corresponding region of the first pixel unit (P1) are controlled to be in a transparent state or a fog state, at this time, light directly passes through the first cholesteric liquid crystal layer (13) and the second cholesteric liquid crystal layer (23).

Description

Reflective display device and driving method Technical Field The present invention relates to the field of display technologies, and in particular, to a reflective display device and a driving method thereof. Background The display panel has the advantages of light weight, durability, energy conservation, environmental protection, low power consumption and the like, but needs to be matched with a backlight source, so that the module is thick and the cost is high. The electronic paper display (reflective display) is a display meeting the needs of the public, and the electronic paper display can display images by using an external light source, unlike a liquid crystal display which needs a backlight, so that information on the electronic paper can still be clearly seen in an environment with strong outdoor sunlight without a problem of visual angle, and the electronic paper display has been widely applied to electronic readers (such as electronic books and electronic newspapers) or other electronic components (such as price tags) because of the advantages of power saving, high reflectivity, contrast ratio and the like. Existing electronic paper displays typically employ E-Ink microcapsule technology (microcapsule electronic Ink technology), siPix microcup technology (microcup electrophoretic display technology), bridgestone electronic liquid powder technology, cholesteric liquid crystal display (Cholesteric Liquid CRYSTAL DISPLAY, CLCD) technology, microelectromechanical system (MEMS) technology, or electrowetting (electrowetting) technology. However, the existing electronic paper display technology is not mature relatively to the liquid crystal display technology, the mass production efficiency is low, the manufacturing cost is relatively high, and the existing electronic paper display cannot realize color display. In the prior art, a reflective display device adopting cholesteric liquid crystal only can reflect one color and transmit light rays of other colors due to the requirement of the pitch of the cholesteric liquid crystal. Therefore, the reflective display device of single-layer cholesteric liquid crystal is mostly displayed in the forms of yellow-background black characters or black-background yellow characters, black-background red characters or red-background black characters, and the like, and can not realize the display of black-background white characters or white-background black characters like books, so that the reflective display device is greatly limited in product application, and the color of the reflective light of the cholesteric liquid crystal is poor, so that the display effect is affected. If white display or color display is required to be realized, the reflective display device needs to use three layers of cholesteric liquid crystal boxes to reflect red/green/blue light respectively, so that white display and color display are realized, but the three layers of cholesteric liquid crystal boxes are large in box thickness, and each layer of cholesteric liquid crystal box needs to be provided with a thin film transistor array substrate, so that the cost is high. Disclosure of Invention In order to overcome the defects and shortcomings in the prior art, the invention aims to provide a reflective display device and a driving method thereof, so as to solve the problem that three layers of cholesteric liquid crystal boxes are needed to realize full-color reflective display in the prior art. The aim of the invention is achieved by the following technical scheme: The invention provides a reflective display device, which comprises a first liquid crystal box and a second liquid crystal box, wherein the second liquid crystal box is laminated on the light emitting side of the first liquid crystal box, the first liquid crystal box is provided with a plurality of first pixel units distributed in an array, the second liquid crystal box is provided with a plurality of second pixel units distributed in an array, and each second pixel unit at least corresponds to one first pixel unit; The first liquid crystal box comprises a first opposite substrate, a first array substrate and a first cholesteric liquid crystal layer, wherein the first array substrate is arranged opposite to the first opposite substrate, the first cholesteric liquid crystal layer is positioned between the first opposite substrate and the first array substrate, the first opposite substrate is positioned on one side of the first liquid crystal box facing the second liquid crystal box, the first cholesteric liquid crystal layer comprises first cholesteric liquid crystal molecules, the first cholesteric liquid crystal molecules reflect light rays with the same color in a reflection state, a first pixel electrode corresponding to the first pixel unit is arranged on the first array substrate, and a first common electrode matched with the first pixel electrode is arranged on the first opposite substrate; The second liquid crystal box compr