Invention Grant
- Patent Title: Identification medium and method for identification thereof
- Patent Title (中): 识别介质及其识别方法
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Application No.: US13518414Application Date: 2010-11-08
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Publication No.: US08976449B2Publication Date: 2015-03-10
- Inventor: Tohru Ida
- Applicant: Tohru Ida
- Applicant Address: JP Yokohama-shi
- Assignee: NHK Spring Co., Ltd.
- Current Assignee: NHK Spring Co., Ltd.
- Current Assignee Address: JP Yokohama-shi
- Agency: Oliff PLC
- Priority: JP2010-016584 20100128
- International Application: PCT/JP2010/069817 WO 20101108
- International Announcement: WO2011/092922 WO 20110804
- Main IPC: G03H1/00
- IPC: G03H1/00 ; G02B5/30 ; G02B27/28 ; G06K9/74 ; B42D25/29 ; G03H1/02 ; B42D25/328 ; B42D25/391

Abstract:
An identification medium, in which a pattern is clearly altered in observation through a right-handed circularly polarizing filter and observation through a left-handed circularly polarizing filter, is provided. The identification medium is formed by laminating a cholesteric liquid crystal layer, a λ/4 plate, and a linearly polarizing filter layer, in that order, from an observing side. The cholesteric liquid crystal layer is formed with a hologram and selectively reflects light. In an observation through a circularly polarizing filter that transmits the light reflected at the cholesteric liquid crystal layer, light reflected at a pattern printed layer is not perceived due to the function of a circularly polarizing layer. Images are clearly altered by switching a right-handed and a left-handed circularly polarizing filter.
Public/Granted literature
- US20120262767A1 IDENTIFICATION MEDIUM AND METHOD FOR IDENTIFICATION THEREOF Public/Granted day:2012-10-18
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