CN-121995674-A - Reflective liquid crystal display panel, preparation method thereof and reflective liquid crystal display device

CN121995674ACN 121995674 ACN121995674 ACN 121995674ACN-121995674-A

Abstract

The application relates to the technical field of liquid crystal display devices, in particular to a reflective liquid crystal display panel, a preparation method thereof and a reflective liquid crystal display device. The reflective liquid crystal display panel comprises a first substrate, a liquid crystal layer and a second substrate which are sequentially stacked, wherein the raw material components of the cholesteric liquid crystal composition comprise nematic liquid crystal, a hydrophobic first chiral compound and a hydrophilic second chiral compound, the optical rotations of the first chiral compound and the second chiral compound are opposite, and a hydrophilic interface is formed on one side of the first substrate and one side of the second substrate, which faces the liquid crystal layer. Breaks through the limit that the theoretical reflectivity of the single rotation cholesterol liquid crystal is not more than 50 percent, and improves the whole reflectivity and the display brightness. Because the components with different optical rotation are vertically layered in the same liquid crystal continuous phase, and an independent double-layer structure is formed by external lamination, no obvious independent mechanical interface exists between the layers, the light scattering loss can be reduced, and the optical coupling efficiency is improved.

Inventors

BI JINGZE
LI MINGXU
XIA JUNWEI
Feng Linger
ZHENG LIBIN
LIN XIQIAN
LI JIEWEI

Assignees

惠科股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260409

Claims (11)

1. The reflective liquid crystal display panel is characterized by comprising a first substrate, a liquid crystal layer and a second substrate which are sequentially laminated, wherein the liquid crystal layer comprises a liquid crystal film prepared from a cholesterol type liquid crystal composition; The raw material components of the cholesterol type liquid crystal composition comprise nematic liquid crystal, a hydrophobic first chiral compound and a hydrophilic second chiral compound, wherein the optical rotation of the first chiral compound and the optical rotation of the second chiral compound are opposite; one side of the first substrate and the second substrate facing the liquid crystal layer is formed with a hydrophilic interface.
2. The reflective liquid crystal display panel according to claim 1, wherein the first chiral compound is selected from the group consisting of R811, S811, CB15 (S), CB15 (R), R1011, and S1011.
3. The reflective liquid crystal display panel according to claim 1, wherein the second chiral compound is selected from the group consisting of R811-OH, S811-OH, R1011-OH, S1011-OH, a dihydroxyl modified chiral compound, a polyoxyethylene ether modified chiral compound, and a carboxyl modified chiral compound.
4. The reflective liquid crystal display panel of claim 1, wherein the raw material components of the cholesteric liquid crystal composition further comprise a photoinitiator and a polymerization monomer, the photoinitiator being configured to initiate polymerization of the polymerization monomer upon exposure to light.
5. The reflective liquid crystal display panel of claim 4, wherein said photoinitiator is selected from the group consisting of TPO, DMAP, photoinitiator 907 and photoinitiator 184, and said polymerized monomer is selected from the group consisting of 2-EHA, TMPTA, PEGMEA and HEMA.
6. The reflective liquid crystal display panel according to claim 1, wherein the hydrophilic interface is formed by oxygen plasma bombardment on a surface of the substrate, by ultraviolet ozone treatment on a surface of the substrate, or by applying a hydrophilic coating.
7. The reflective liquid crystal display panel according to any one of claims 1 to 6, wherein the other of the first substrate and the second substrate is formed with a hydrophobic interface toward a side of the liquid crystal layer.
8. The reflective liquid crystal display panel of claim 7, wherein the hydrophobic interface is formed by CF 4 plasma bombardment of the surface of the substrate, C 4 F 8 plasma bombardment of the surface of the substrate, or a hydrophobic coating.
9. The reflective liquid crystal display panel of claim 7, wherein the first substrate is positioned on a display side of the reflective liquid crystal display panel relative to the second substrate, the hydrophobic interface is positioned on a side of the first substrate facing the liquid crystal layer, and the hydrophilic interface is positioned on a side of the second substrate facing the liquid crystal layer.
10. A method for manufacturing a reflective liquid crystal display panel according to any one of claims 1 to 9, comprising: Respectively providing a first substrate and a second substrate, and carrying out hydrophilization treatment on the inner surface of one of the substrates to form a hydrophilic interface and a rubber frame; mixing the raw material components of the cholesterol type liquid crystal composition to obtain a uniform and stable liquid crystal composition mixed system; coating the liquid crystal composition mixed solution on the surface of the first substrate or the second substrate to form a liquid crystal film structure; the first substrate and the second substrate are mutually buckled, so that the first substrate and the second substrate are connected through the rubber frame.
11. A reflective liquid crystal display device comprising a reflective liquid crystal display panel according to any one of claims 1 to 9.

Description

Reflective liquid crystal display panel, preparation method thereof and reflective liquid crystal display device Technical Field The application relates to the technical field of liquid crystal display devices, in particular to a reflective liquid crystal display panel, a preparation method thereof and a reflective liquid crystal display device. Background Although the conventional display panel (such as a liquid crystal display panel) has the characteristics of light weight, durability, energy saving, environmental protection and low power consumption, the backlight source is required to be matched for use, so that the overall thickness of the module is increased, and the production and application costs are increased. In this context, electronic paper reflective displays are new display schemes that meet the needs of the public. The display can realize image display by means of external natural or environmental light sources without relying on backlight sources like a liquid crystal display, so that a user can clearly read information on electronic paper even in a scene with strong outdoor sunlight, and the problem of limited viewing angle does not exist. The current mainstream electronic paper display technology routes are various, and common technologies include an E-Ink microcapsule technology (microcapsule electronic Ink technology), a SiPix microcup technology (microcup type electrophoretic display technology), a Bridgestone electronic liquid powder technology, a cholesterol type liquid crystal display technology (Cholesteric Liquid CRYSTAL DISPLAY, abbreviated as CLCD) and an electrowetting (Electrowetting) technology. Among these, the cholesteric liquid crystal display technology has a core advantage in that its bistable property is embodied in two stable states of a planar state and a focal conic state, because the cholesteric liquid crystal therein has a specific pitch, and when the pitch is close to the wavelength of incident light, a specific optical rotation in a specific wavelength can be selectively reflected. When a voltage is applied thereto, the alignment state of the cholesteric liquid crystal molecules can be regulated so that it switches between these two stable states. In contrast, when the cholesteric liquid crystal is in a focal conic state, the light can directly penetrate. Based on this characteristic, the cholesteric liquid crystal can be controlled to take a state of "allowing light to pass through" or "reflecting light of a specific wavelength" by applying a voltage thereto. This process allows the display content to be maintained without the need for continuous power, greatly reducing power consumption. The characteristics enable the electronic book to be widely applied to the product fields of electronic books, electronic papers, electronic whiteboards, outdoor billboards and the like which have requirements on low power consumption. However, the existing single-color cholesterol type liquid crystal display technology has a core bottleneck which is difficult to break through. The traditional single-layer structure is limited by the principle of single-rotation reflection of the liquid crystal layer, and the theoretical reflectivity cannot break through 50%, so that the display brightness is insufficient, and the visibility under outdoor strong light is poor. In the related art, there are two-layer structure schemes attempting to break the reflectivity limit, namely, a physical stacking process is generally adopted to prepare a left-handed liquid crystal layer and a right-handed liquid crystal layer respectively, and then physical lamination or secondary coating is carried out, so that the step-by-step manufacturing process has the remarkable defects that on one hand, the production cost and time are increased by two independent coating or printing procedures, the yield is reduced, on the other hand, the two-layer liquid crystal layer structure lacks sufficient mechanical support, interlayer slippage or uneven thickness is easy to occur when external pressure or bending is carried out, so that color spots and performance decline are displayed, and on the other hand, physical spacing layers or air are inevitably present among materials of the multi-layer liquid crystal layer, so that the reflectivity improvement is limited. Disclosure of Invention The application aims to solve the technical problems that the single-layer structure cholesterol type liquid crystal layer has insufficient reflectivity, and the cholesterol type liquid crystal layer adopting the double-layer physical lamination structure has complex process, high cost and poor mechanical stability, and the reflectivity is limited to be improved due to the existence of a physical spacing layer or air between layers. In order to solve the technical problems, the embodiment of the application provides a reflective liquid crystal display panel, a preparation method thereof and a reflective liquid crystal display device.