US 12,292,623 B2
Display apparatus
Harish Bhaskaran, Horton-cum-Studley (GB); Peiman Hosseini, Bicester (GB); and Ben Broughton, Marston (GB)
Assigned to E Corporation, Billerica, MA (US)
Filed by E INK CORPORATION, Billerica, MA (US)
Filed on Oct. 27, 2023, as Appl. No. 18/384,522.
Application 18/384,522 is a continuation of application No. 16/469,167, granted, now 11,846,835, previously published as PCT/GB2017/053270, filed on Oct. 31, 2017.
Claims priority of application No. 1621178 (GB), filed on Dec. 13, 2016.
Prior Publication US 2024/0053624 A1, Feb. 15, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. G02F 1/01 (2006.01); B42D 25/36 (2014.01); C09K 5/14 (2006.01); G02F 1/00 (2006.01); H10N 70/00 (2023.01); H10N 70/20 (2023.01); H04N 9/31 (2006.01)
CPC G02F 1/01 (2013.01) [B42D 25/36 (2014.10); C09K 5/14 (2013.01); G02F 1/0054 (2013.01); H10N 70/231 (2023.02); H10N 70/8613 (2023.02); H10N 70/882 (2023.02); H10N 70/8825 (2023.02); H10N 70/8828 (2023.02); G02F 1/0147 (2013.01); G02F 2202/10 (2013.01); G02F 2203/12 (2013.01); H04N 9/312 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A display apparatus, comprising:
a reflective layer comprising reflective material, and one or more stacks of additional layers provided on a first side of the reflective layer, wherein each stack comprises an optically switchable layer;
a plurality of switching elements located on a second side of the reflective layer opposite to the first side or forming part of the reflective layer, each switching element being operable to apply a signal through the reflective layer to a switchable portion of the optically switchable layer and thereby change an appearance of the switchable portion when viewed from a viewing side of the display apparatus, wherein
the optically switchable layer comprises a phase change material, the phase change material being switchable between a plurality of stable states, each of the stable states having a different refractive index relative to each of the other stable states, the phase change material being switchable by application of heat between the plurality of stable states; and
the optically switchable layer is configured such that switching of the optically switchable layer causes the apparatus to provide one or both of the following effects for incident radiation within a predetermined frequency range:
(i) a change in reflectivity of a factor of at least 50; or
(ii) a change in phase that is within 5% of nπ/2 radians, where n is an integer.