US 12,332,511 B2
Method of forming a pattern on an optical device
Peiman Hosseini, Oxon (GB); Lokeshwar Bandhu, Oxford (GB); and Ben Broughton, Oxford (GB)
Assigned to E Ink Corporation, Billerica, MA (US)
Appl. No. 17/772,168
Filed by E INK CORPORATION
PCT Filed Oct. 21, 2020, PCT No. PCT/GB2020/052635
§ 371(c)(1), (2) Date Apr. 27, 2022,
PCT Pub. No. WO2021/084228, PCT Pub. Date May 6, 2021.
Claims priority of application No. 1915606 (GB), filed on Oct. 28, 2019.
Prior Publication US 2022/0382081 A1, Dec. 1, 2022
Int. Cl. G02F 1/01 (2006.01); B41J 2/21 (2006.01)
CPC G02F 1/0147 (2013.01) [B41J 2/21 (2013.01)] 18 Claims
OG exemplary drawing
 
9. A method of forming a pattern on an optical device, wherein:
the optical device comprises a plurality of pixel elements, each pixel element comprising a stack of layers that includes a color control layer and a brightness control layer superposed over each other in a viewing direction; and
the method comprises, for each of one or more of the pixel elements:
depositing energy into the color control layer of the pixel element to modify the color control layer and thereby change an effect of the color control layer on the color of light leaving the optical device from the pixel element in use; and
depositing energy into the brightness control layer of the pixel element to modify the brightness control layer and thereby change an effect of the brightness control layer on the intensity of light leaving the optical device from the pixel element in use, wherein:
the color control layer comprises a phase change material switchable between a plurality of stable states having different refractive indices relative to each other; and
the depositing of energy into the color control layer of each pixel element is arranged to switch the color control layer in the pixel element from one of the states to another of the states, and wherein the stack of layers in each pixel element further comprises a reflective layer and the brightness control layer of each stack is provided on a side of the color control layer opposite to the reflective layer.