Information-recorded media and methods for reading the information
First Claim
1. An information-recorded medium which includes a layer with a hologram recorded thereon that is composed of a hologram having interference fringes recorded in a transmittance profile or refractive index profile form in a thickness direction of the optical recording material, wherein spacings between interference fringes are made wide or narrow in a portion or portions of the hologram so as to conform to additionally written information, thereby making a wavelength reconstructed by the resultant portion different from that of another portion of the hologram.
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Accused Products
Abstract
The invention is directed to an information-recorded medium with easily selectable and identifiable items of information, which is virtually protected against forgery and has enhanced security against some improper use, and a method for reading such a medium. This information-recorded medium 1 includes a substrate 2 and a layer 3 with information recorded thereon by the printing of infrared absorbing ink, said layer 3 being provided on the surface of the layer 2. The printed layer 3 is provided thereon with a relief hologram-recorded layer 7 through an adhesive layer 4, said hologram-recorded layer 7 being built up of a reflecting layer 5 transparent to the infrared region and a relief hologram-formed layer 6 provided on the surface of the reflecting layer 5. For reading, the hologram-recorded layer 7 is reconstructed by visible light, while the printed layer is reconstructed by infrared light, and the medium 1 is identified on the basis of the thus reconstructed information.
259 Citations
22 Claims
- 1. An information-recorded medium which includes a layer with a hologram recorded thereon that is composed of a hologram having interference fringes recorded in a transmittance profile or refractive index profile form in a thickness direction of the optical recording material, wherein spacings between interference fringes are made wide or narrow in a portion or portions of the hologram so as to conform to additionally written information, thereby making a wavelength reconstructed by the resultant portion different from that of another portion of the hologram.
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6. A medium having information recorded thereon, comprising a first layer with a hologram or a diffraction grating recorded thereon and a second layer with information recorded thereon by printing, each layer having at least an information recorded thereon, wherein
the first layer comprises a shielding layer; -
a hologram or diffraction grating is recorded on the first layer; the first layer is deposited above the second layer, the first layer reflects visible light and transmits invisible light; the second layer has a component to reflect or absorb invisible light; and the information on the second layer is shielded by the first layer under visible light and can be read through the first layer under invisible light without interfering with reading of the first layer. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification