Patent ID: 8704984

Claim:
A method of preparing a composite optical retarder, comprising: (a) providing a first support substrate; (b) forming an photoalignment film by coating a photoalignment resin on a top surface of the first support substrate, and irradiating an exposed first surface of the photoalignment resin with first linearly polarized ultraviolet having a first polarized direction and a first dosage to perform a first photoalignment reaction; (c) forming a first optical retarder on an exposed first surface of the photoalignment film by coating a first liquid crystal coating material on the exposed first surface of the photoalignment film, and irradiating the first liquid crystal coating material with first non-polarized ultraviolet to cure the first liquid crystal coating material; (d) exposing an opposite second surface of the photoalignment film by adhering a second support substrate onto the first optical retarder, and removing the first support substrate from the second surface of the photoalignment film; (e) irradiating the second surface of the photoalignment film with second linearly polarized ultraviolet having a second polarized direction and a second dosage to perform a second photoalignment reaction, wherein the first and the second polarized directions are different and the second dosage is greater than the first dosage; and (f) forming a second optical retarder on the second surface of the photoalignment film by coating a second liquid crystal coating material on the second surface of the photoalignment film, and irradiating the second liquid crystal coating material with second non-polarized ultraviolet to cure the second liquid crystal coating material.