发明授权
- 专利标题: System for determining the authenticity of an object
- 专利标题(中): 用于确定对象的真实性的系统
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申请号: US122265申请日: 1993-08-16
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公开(公告)号: US5497227A公开(公告)日: 1996-03-05
- 发明人: Itsuo Takeuchi , Hidekazu Hoshino , Mutumi Sasaki
- 申请人: Itsuo Takeuchi , Hidekazu Hoshino , Mutumi Sasaki
- 申请人地址: JPX Kanagawa
- 专利权人: NHK Spring Co., Ltd.
- 当前专利权人: NHK Spring Co., Ltd.
- 当前专利权人地址: JPX Kanagawa
- 优先权: JPX4-285270 19920929
- 主分类号: B42D15/10
- IPC分类号: B42D15/10 ; G02B27/28 ; G06K7/10 ; G06K19/06 ; G06K19/10 ; G06K19/16 ; G06T1/00 ; G07F7/08 ; G06K9/74 ; G03H1/00
摘要:
Provided is an identification system which is highly effective in identifying the authenticity of an object and extremely difficult to analyze for the purpose of forgery. The object to be identified is affixed with an identification element comprising a reflective layer including a hologram, a diffraction grating or the like, which directs incident light of a prescribed wave length into a plurality of point symmetric directions, and a polarization plane rotating layer which rotates the polarization plane of the light as it passes through the polarization rotating layer. A linearly polarized light is impinged upon the identification element, and is received by a multisegment photodiode arranged in an annular fashion. Those photodiode segments located on one side of a diametric line is covered by a first filter adapted to transmit substantially only the light emitted from the identification element whose plane of polarization is rotated by the polarization plane rotating layer while remaining segments are covered by a second filter adapted to transmit substantially only the light emitted from the identification element whose plane of polarization is not rotated by the polarization plane rotating layer. Thus, by detecting the ratios of the intensities of light received by each pair of diametrically opposing photodiode segments, the authenticity of the identification element or the authenticity of the object can be reliably detected.
公开/授权文献
- US4330051A Drive controlling mechanism 公开/授权日:1982-05-18