US 11,841,560 B2
Depolarizing plate
Akio Takada, Sendai (JP); Eiji Takahashi, Tagajo (JP); Nobuyuki Koike, Sendai (JP); Koji Sasaki, Miyagi (JP); and Naoki Hanashima, Sendai (JP)
Assigned to Dexerials Corporation, Tokyo (JP)
Filed by Dexerials Corporation, Tokyo (JP)
Filed on Feb. 18, 2021, as Appl. No. 17/178,244.
Application 17/178,244 is a continuation of application No. 15/185,305, filed on Jun. 17, 2016, granted, now 11,002,993.
Claims priority of application No. 2015-123101 (JP), filed on Jun. 18, 2015.
Prior Publication US 2021/0181541 A1, Jun. 17, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. G02F 1/01 (2006.01); G02B 5/30 (2006.01); G02B 1/14 (2015.01); G02F 1/1335 (2006.01)
CPC G02F 1/0136 (2013.01) [G02B 5/3083 (2013.01); G02B 1/14 (2015.01); G02F 1/1335 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A depolarizing plate comprising
a light-transmitting substrate having a surface layer portion in which a fine pattern is provide, wherein
the fine pattern includes a plurality of curved lines of lands each having a protruding shape and a plurality of grooves formed between the lands and each having a recessed shape composed of an air layer between the lands,
the curved lines are randomly disposed,
each pair of one of the curved lines and adjacent one of the grooves defines a distance L+S where L is a width of the curved line and S is a width of the groove,
the distance L+S is no greater than a wavelength of visible light, and
the fine pattern exhibits structural birefringence.