Patent ID: 7995256
Filing Date: 2011-08-09
Classification: G03H

Abstract:
1. An apparatus for recognizing a card with a transmission type Fourier transform lens having a computer generated hologram part comprising a point light source; a supporting part for supporting a card with a transmission type Fourier transform lens having a computer generated hologram part, disposed such that a light from the point light source is incident on the computer generated hologram part of the card with a transmission type Fourier transform lens having a computer generated hologram part; and a light receiving part for receiving the light transmitted the card with a transmission type Fourier transform lens having a computer generated hologram part supported by the supporting part, wherein the point light source, the computer generated hologram part supported by the supporting part, and the light receiving part are disposed in one straight line, wherein the card with a transmission type Fourier transform lens having a computer generated hologram part comprises a configuration with a transparent card substrate made of a resin transparent with respect to a visible light, and a hologram layer having the computer generated hologram part to function as a transmission type Fourier transform lens laminated, wherein the hologram layer is formed in an uppermost layer and has a plural layer structure with a transparent substrate, an image converting layer, a diffraction function layer, and a protection layer, wherein a minute concavo-convex shape on a surface of the hologram layer is multistage, wherein a refractive index of the hologram layer at 633 nm wavelength is in the range of 1.3 to 2.0, and wherein a light transmittance of the transparent card substrate in a visible light range is 80% or more.