KR-20260064966-A - VIEWING ANGLE ADJUSTABLE PANEL USING POLYMER DISPERSED LIQUID CRYSTAL CAPSULES, DISPLAY DEVICE AND ELETRONIC APPARATUS HAVING THE SAME

Abstract

The present invention relates to a viewing angle control panel using a polymer-dispersed liquid crystal capsule, a display element equipped with the same, and an electronic device. The present invention discloses a viewing angle control panel using a polymer-dispersed liquid crystal capsule, characterized by comprising: a first substrate and a second substrate facing each other; a first transparent electrode formed on the opposite surface of the first substrate facing the second substrate; a second transparent electrode formed on the opposite surface of the second substrate facing the first substrate; and a dye-type liquid crystal capsule bonded between the first transparent electrode and the second transparent electrode by a binder matrix, wherein the dye-type liquid crystal capsule comprises a dichroic dye. According to an embodiment of the present invention, a viewing angle control panel capable of controlling transmittance and viewing angle is provided by mixing a dichroic dye into a liquid crystal at a certain ratio and then encapsulating it, thereby utilizing a polymer-dispersed liquid crystal capsule in a liquid crystal capsule method.

Inventors

• 황현하
• 강승곤

Assignees

• 이미지팹 주식회사

Dates

Publication Date

20260508

Application Date

20241030

Claims (16)

1. First substrate and second substrate facing each other; A first transparent electrode formed on the opposite surface of the first substrate facing the second substrate; A second transparent electrode formed on the opposite surface of a second substrate facing the first substrate; and A liquid crystal capsule layer comprising dye-type liquid crystal capsules bonded by a binder matrix between the first transparent electrode and the second transparent electrode. - The above dye-type liquid crystal capsule contains a dichroic dye - A viewing angle control panel using a polymer-dispersed liquid crystal capsule characterized by including
2. In Article 1, A viewing angle control panel using a polymer-dispersed liquid crystal capsule, characterized in that the dye-type liquid crystal capsule has an average particle size between 0.2 µm and 2.0 µm.
3. In Article 1, A viewing angle control panel using a polymer-dispersed liquid crystal capsule, characterized in that the refractive index anisotropy (Δn) of the liquid crystal used in the dye-type liquid crystal capsule is 0.2 or higher.
4. In Article 1, A viewing angle control panel using a polymer-dispersed liquid crystal capsule, characterized in that the concentration of the dichroic dye of the dye-type liquid crystal capsule is between 0.1 wt% and 10.0 wt% relative to the liquid crystal.
5. In Article 1, A viewing angle control panel using a polymer-dispersed liquid crystal capsule, characterized in that the dichroic dye of the above-mentioned dye-type liquid crystal capsule is black.
6. In Article 1, A viewing angle control panel using a polymer-dispersed liquid crystal capsule, characterized in that the dichroic dye of the above-mentioned dye-type liquid crystal capsule exhibits a color and consists of one or more selected from magenta, yellow, and cyan.
7. In Article 1, A viewing angle control panel using a polymer-dispersed liquid crystal capsule, characterized in that the binder matrix is a water-soluble polymer and is at least one selected from polyvinyl alcohol (PVA), gelatin, gum arabic, starch, carboxymethylcellulose, ethylcellulose, polyvinylpyrrolidone, and casein.
8. In Article 1, A viewing angle control panel using a polymer-dispersed liquid crystal capsule, characterized in that the transparent electrode is composed of any one selected from ITO (Indium Tin Oxide), TCO (Transparent Conductive Oxide), silver nanowires (Ag NW), a polymer material composed of PEDOT:PSS, CNT (Carbon Nano Tube), graphene, and a mixture of graphene and CNT.
9. In Article 1, A viewing angle control panel using a polymer-dispersed liquid crystal capsule, characterized in that the substrate is composed of any one selected from PET, PES, TAC, PAR, PC, PEN, COP, and CPI (Clear PI).
10. In Article 1, A viewing angle control panel using a polymer-dispersed liquid crystal capsule, characterized in that the thickness of the liquid crystal capsule layer is between 5 µm and 30 µm.
11. Display panel and A viewing angle adjustment panel using a polymer-dispersed liquid crystal capsule selected from any one of claims 1 to 10, provided on the upper part of the above display panel. A display element characterized by including
12. In Paragraph 11, A display element characterized by having a haze of 98% or more in the power-off state and an overall transmittance of 5% or less in the power-off state.
13. In Paragraph 11, A display element characterized by having an on-axis transmittance [Toff(On-axis)] of 0.1% or less in the power-off state.
14. In Paragraph 11, A display device characterized in that the above-described display panel is an OLED panel.
15. Display panel and A display element comprising a viewing angle adjustment panel using a polymer-dispersed liquid crystal capsule selected from any one of claims 1 to 10, provided on the upper part of the above display panel. An electronic device including
16. In Paragraph 15, The above electronic device is characterized as being any one selected from a laptop, tablet PC, smartphone, smartwatch, finger ring, POS device, and ATM machine.

Description

Viewing angle adjustable panel using polymer-dispersed liquid crystal capsules, display device and electronic apparatus having the same The present invention relates to a viewing angle control panel using a polymer-dispersed liquid crystal capsule, a display element equipped with the same, and an electronic device. More specifically, it relates to a viewing angle control panel using a polymer-dispersed liquid crystal capsule that improves the low contrast ratio characteristic, which is the biggest drawback of existing commercially available polymer-dispersed liquid crystal (PDLC) displays, by applying a dichroic dye and a liquid crystal capsule method, and to a display element equipped with the same. A polymer dispersed liquid crystal (PDLC) display device has liquid crystal droplets in a polymer matrix This is a display device that utilizes the principle in which incident light is scattered or transmitted due to the difference in refractive index between the polymer matrix and the liquid crystal when an electric field is applied to a dispersed state (Overseas Patent US 4,688,900, Domestic Patent 10-0255624). Since this polymer-dispersed liquid crystal display device does not require an alignment layer and does not use a polarizer, it has the advantages of a simple manufacturing process and high light transmittance in the On-state. On the other hand, because the light transmittance in the Off-state is also relatively high, it has the disadvantage of a very low contrast ratio depending on the voltage On/Off. Because this polymer-dispersed liquid crystal display device has low resolution for use as a display, it is sometimes used as a low-cost optical shutter that controls transmittance depending on whether power is applied. Therefore, it may be more appropriate to call it an optical shutter using polymer-dispersed liquid crystal rather than a polymer-dispersed liquid crystal display device; however, since it is also used as a display device, it will be referred to as a display device. Attempts to improve contrast ratio characteristics by mixing a dichroic dye into the liquid crystal layer to overcome the disadvantages of such polymer-dispersed liquid crystal display devices have been reported (Korean Patent 10-1598539). When the dichroic dye is mixed with the liquid crystal, it tends to align with the movement of the liquid crystal due to interaction with the liquid crystal molecules. Therefore, it is known that when the dichroic dye is mixed into the aforementioned polymer-dispersed liquid crystal layer, changes in optical transmittance characteristics occur as it is aligned or randomly distributed under the influence of the movement of the liquid crystal due to the application of an external electric field. FIG. 1 is an overall process diagram for manufacturing a viewing angle control panel using a polymer-dispersed liquid crystal capsule according to one embodiment of the present invention. FIG. 2 is a diagram showing the configuration and operating principle of a viewing angle control panel using a polymer-dispersed liquid crystal capsule to which a dye according to the present invention is applied. Figure 3 is measurement data showing the viewing angle characteristics of a viewing angle control panel using a polymer-dispersed liquid crystal capsule according to the present invention. FIG. 4 is an explanatory diagram of the operation of a display element according to an embodiment of the present invention, wherein a viewing angle adjustment panel using a polymer-dispersed liquid crystal capsule manufactured according to the present invention is combined on the upper part of a display panel. The terms used in this invention are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. In addition, in this specification, the phrase “on or above” means being located above or below the target part, and does not necessarily mean being located on the upper side with respect to the direction of gravity. Furthermore, when a part such as a region or plate is said to be “on or above” another part, this includes not only cases where it is in contact with or spaced apart from the other part “immediately on or above” the other part, but also cases where there is another part in between. In addition, when a component is described in this specification as being "connected" or "connected" to another component, it should be understood that the component may be directly connected to or directly connected to