The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 13, 2004
Filed:
Apr. 17, 2002
Sumitomo Chemical Company, Limited, Osaka, JP;
Abstract
The present invention provides a phase retarder made of a copolymer prepared by polymerizing one non-cyclic olefin monomer (A) selected from ethylene and &agr;-olefin compound having 3 to 20 carbon atoms, one cyclic olefin monomer (B) selected from cyclic olefin compound such as norbornene, and one cyclic vinyl monomer (C) selected from vinyl compound having a cyclic unit made of an aromatic hydrocarbon or an alicyclic hydrocarbon such as styrene or vinylcyclohexane; wherein (1) an amount of the aromatic vinyl monomer is from about 1 to about 20 mol % and a total amount of the non-cyclic olefin monomer (A) and the cyclic olefin monomer (B) is from about 80 to about 99 mol % in case the component (C) is the aromatic vinyl monomer, or (2) an amount of the alicyclic vinyl monomer is from about 80 to about 99 mol % and a total amount of the non-cyclic olefin monomer and the cyclic olefin monomer is from about 1 to about 20 mol % in case the component (C) is the alicyclic vinyl monomer. The present phase retarder makes it possible to conduct uniform polarizing conversion within a wide wavelength range using a single plate.