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:
Feb. 09, 2016
Filed:
Feb. 24, 2011
Nobuyuki Hashimoto, Iruma, JP;
Makoto Kurihara, Kawagoe, JP;
Kenji Matsumoto, Tokyo, JP;
Masafumi Yokoyama, Tokyo, JP;
Ayano Tanabe, Tokyo, JP;
Nobuyuki Hashimoto, Iruma, JP;
Makoto Kurihara, Kawagoe, JP;
Kenji Matsumoto, Tokyo, JP;
Masafumi Yokoyama, Tokyo, JP;
Ayano Tanabe, Tokyo, JP;
CITIZEN HOLDINGS CO., LTD., Tokyo, JP;
Abstract
A polarization conversion element includes a phase reversal element and a polarization plane rotation element including a liquid crystal layer. The liquid crystal layer has a plurality of regions disposed along circumferential direction with the intersection point of the polarization plane rotation element and the optical axis as the center with alignment directions different from each other. When electric voltage in accordance with the wavelength of linear polarization incident on the polarization plane rotation element is applied, each region rotates the polarization plane of the polarization component transmitted by each region, and thereby converts linear polarization to radial polarization. The phase reversal element reverses, among the first and the second annular portions alternately disposed along the radial direction with the optical axis as the center, the phase of light incident on the first annular portion relative to the phase of light incident on the second annular portion.