Optical Device

Abstract

An optical device is provided in the present application. The present application provides an optical device capable of varying transmittance, and such optical device can be used for various applications such as eyewear, for example, sunglasses or AR (augmented reality) or VR (virtual reality) eyewear, an outer wall of a building or a sunroof for a vehicle.

Claims

1. An optical device, comprising: first and second outer substrates disposed to face each other; and an active liquid crystal element encapsulated between the first and second outer substrates, wherein at least one of the first and second outer substrates is a curved substrate.

2. The optical device according to claim 1, wherein the first and second outer substrates are both curved substrates.

3. The optical device according to claim 1, wherein a difference between curvature radii of the first and second outer substrates is within 10%.

4. The optical device according to claim 1, wherein curvatures of the first and second outer substrates are different from each other.

5. The optical device according to claim 1, wherein a curvature radius of the curved substrate is from 100R to 10,000R.

6. The optical device according to claim 1, wherein, among the first and the second outer substrates, one of outer substrates that exists at an upper position in a direction along a convex direction formed by the curved substrate has a larger curvature radius than the other outer substrate that exists at a lower position in a direction along the convex direction formed by the curved substrate.

7. The optical device according to claim 1, wherein the first or the second outer substrate is a glass substrate.

8. The optical device according to claim 2, wherein curvature centers of the first and second outer substrates are present in the same portion of an upper part or a lower part of the first and second outer substrates.

9. The optical device according to claim 1, wherein a thickness at a center of gravity is thinner than a thickness at a rim.

10. The optical device according to claim 9, wherein a thickness difference between the thickness at the center of gravity and the thickness at the rim is 0.5% or more.

11. The optical device according to claim 1, further comprising a polarizer encapsulated between the first and second outer substrates.

12. The liquid crystal display device according to claim 11, wherein the active liquid crystal element and the polarizer are encapsulated with adhesive films existing between the outer substrate and the active liquid crystal element, between the active liquid crystal element and the polarizer, between the polarizer and the outer substrate, and on the sides of the active liquid crystal element and the polarizer.

13. The optical device according to claim 1, wherein the active liquid crystal element comprises two base films disposed opposite to each other and an active liquid crystal layer existing between the two base films.

14. A method of manufacturing the optical device of claim 1 comprising encapsulating an active liquid crystal element between first and second outer substrates disposed opposite to each other through an autoclave process using an adhesive film, wherein at least one of the first and second outer substrates is a curved substrate.

15. An automobile comprising a body on which one or more openings are formed; and the optical device of claim 1 attached to the openings.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0144] FIGS. 1 to 3 are drawings for explaining a folded structure of a liquid crystal element of the present application.

[0145] FIGS. 4 to 9 are illustrative drawings for explaining an optical device of the present application.

[0146] FIG. 10 is a photograph showing the result of an example.

[0147] FIGS. 11 to 13 are photographs related to thickness measurement of an optical device.

DETAILED DESCRIPTION

[0148] Hereinafter, the scope of the present application will be described in more detail through Examples and Comparative Examples, but the scope of the present application is not limited by the following examples.

[0149] 1. Measurement of Curvature Radius

[0150] A curvature radius of curvature of an outer substrate was measured using a 2D profile laser sensor. Also, in the following, the curvature radii of the respective outer substrates were curvature radii of the surfaces facing each other, and when the curvature radii were not constant and there were different portions, the largest curvature radius was used as a reference.

[0151] 2. Measurement of Thickness

[0152] Thicknesses of the center of gravity and the rim in an optical device were measured using an instrument that a thickness measuring instrument (Mitutoyo, thickness gage 12/0.001 mm 547-401, resolution: 1 m, accuracy: 3 m, range: 0 to 12 mm) was reassembled on a stand as shown in FIG. 11. The zero point of the measuring instrument was first set as in FIG. 11, the thickness was measured as in FIGS. 12 and 13, and then the thickness was determined by confirming whether or not the zero point was correct again.

Example 1

[0153] An optical device was produced by encapsulating a guest-host liquid crystal device (cell gap: about 12 m, base film type: PET (poly(ethylene terephthalate) film), liquid crystal/dye mixture type: mixture of MAT-16-969 liquid crystals from Merck and an anisotropic dye (BASF, X12)) as an active liquid crystal element and a PVA (polyvinyl alcohol)-based polarizer between two outer substrates with thermoplastic polyurethane adhesive films (thickness: about 0.38 mm, manufacturer: Argotec Co., Ltd., product name: ArgoFlex). Here, as the outer substrates, glass substrates having a thickness of about 3 mm or so were used, where a substrate having a curvature radius of about 1030R (first outer substrate) and a substrate having a curvature radius of 1000R (second outer substrate) were used. The difference between the curvature radii of the first and second outer substrates is approximately 3%. A laminate was produced by laminating the first outer substrate, the adhesive film, the active liquid crystal element, the adhesive film, the polarizer, the adhesive film and the second outer substrate in this order, and disposing the adhesive film on all sides of the active liquid crystal element as well. Referring to FIG. 7, the structure of the laminate was in the form of the first outer substrate (curvature radius 1030R, 301), the adhesive film, the active liquid crystal element, the adhesive film, the polarizer, the adhesive film and the second outer substrate (curvature radius 1000R, 302), where the second outer substrate (302) was arranged in the gravity direction as compared to the first outer substrate (301). Thereafter, the optical device was produced by performing an autoclave process at a temperature of about 100 C. and a pressure of about 2 atm or so.

[0154] The thickness at the center of gravity was about 7.82 mm and the thickness at the rim was about 8.03 mm, as measured for the manufactured optical device. Thus, the thickness difference is approximately 2.69% or so. The produced optical device was then applied to a high temperature long term durability test (holding at a temperature of 100 C. for about 168 hours). FIG. 10 is a photograph of the device after the durability test. From the drawing, it can be confirmed that the optical device has been produced stably without occurrence of bubbles or widening of the substrate.

EXPLANATION OF REFERENCE NUMERALS AND SYMBOLS

[0155] 10: active liquid crystal element [0156] 101: first line [0157] 102: second line [0158] A, AA: folded area [0159] D: bisector of the first line [0160] T: Tangent of the bisector of the first line [0161] P: normal to the tangent of the bisector of the first line [0162] 1022: line for measuring the angle of the second line [0163] 20: polarizer [0164] 201: polarizing coating layer [0165] 30: outer substrate [0166] 40: adhesive film [0167] 50: buffer layer [0168] 110: base film [0169] 120: active liquid crystal layer