Abstract: A technique of optical card having high information recording density. In the optical cards, there are two types of optical cards having a read-only optical card and an additional recording optical card. Conventionally, separate readers for reproduction have been used due to difference in light reflectivity. In this invention, a light-absorbing layer (50) having light absorbing ability with respect to reading light (300) is arranged between a card side upon which the reading light is incident and a reflective surface of a pattern (21) of an optical data recording section (20), so that the optical cards have interchangeability therebetween in reading.

Abstract: An optical recording medium includes a silver grain layer containing a large number of blackened fine silver grains and a coloring matter layer containing coloring matter on a base board and the coloring matter has an ability of absorbing near-infrared ray. When laser beam having a density of optical energy more than a boundary which represents a threshold with respect to the density of optical energy is radiated to the optical recording medium, a part of the latter is deformed to form a plurality of convexities which will be utilized as optical recording pit. The recording pits formed in this way are detected by presence or absence of reflection of radiated light whereby the content of optical recorded informations can be read. The optical recording pits are not deformed further irrespective of how long a reading light comprising laser beam having a density of energy less than the threshold is repeatedly radiated to the optical pits.

Abstract: An optical or magneto-optical recording card is produced using a transfer type optical or magneto-optical recording medium. The transfer type optical or magneto-optical recording medium comprises a base film, a peeling layer, an optical or magneto-optical recording layer and a light permeable adhesive layer which are successively superimposed one above another to constitute a layered structure. A protective layer is adhered to the transfer type optical or magneto-optical recording medium with the aid of an adhesive layer and the base film is then peeled off together with the peeling layer. Next, the protective layer to which the optical or magneto-optical recording layer is adhered is adhesively attached to a card base in such a manner that the optical or magneto-optical recording layer is interposed therebetween whereby an optical or magneto-optical recording card is completely produced. The transfer type recording medium can be preserved in such a state that it is wound about a reel.

Abstract: A method of producing a plurality of masks which are used when ROM type data are written in an optical recording medium for ROM type optical recording cards. The method is practiced by way of steps of producing a mother mask having a preformatting pattern, next, transcribing the preformatting pattern for the mother mask, next, producing a master mask having a required optical recording pattern written therein and next, producing a working mask from the master mask. When the preformatting pattern is prepared in a writable type, writing or inspecting of the master mask or inspecting of the working mask or mother mask can be achieved using a writing/reading apparatus for writable type optical recording cards.

Abstract: An optical recording card is produced using a transfer type optical recording medium. The transfer type optical recording medium comprises a base film, a peeling layer, an optical recording layer and a light permeable adhesive layer which are successively superimposed one above another to constitute a layered structure. A protective layer is adhered to the transfer type optical recording medium with the aid of an adhesive layer and the base film is then peeled off together with the peeling layer. Next, the protective layer to which the optical recording layer is adhered is adhesively attached to a card base in such a manner that the optical recording layer is interposed therebetween whereby an optical recording card is completely produced. The transfer type recording medium can be preserved in such a state that it is wound about a reel. Accordingly, the transfer type recording medium is adhered to the protective layer when the optical recording card is produced, and thereafter it is adhered to the card base.

Abstract: In an optical card, a card substrate has its rigidity which is sufficient to handle the card substrate independently. The card substrate has a first side which serves as a reading side upon which reading light is incident. An optical-data recording section includes a light-reflective pattern. The optical-data recording section is arranged on one of the first and second sides of the card substrate. Optical data incident upon the optical-data recording section toward the reading side of the card substrate is recorded by the optical-data recording section. A shielding layer is arranged on one of the first and second sides of the card substrate, for shielding the optical-data recording section from a viewer's field of view. The shielding layer has its transmission characteristic with respect to the reading light, which is sufficient to shield light within a visual range and to enable reading of the optical-data recording section.

Abstract: A certification card such as ID card or the like includes a hologram and an optical recording portion. Hologram is such that an amplitude and a phase of a light wave emitted from an object are recorded and an image of the object is rebuilt by emitting light to reproduce of an amplitude and a phase of the thus emmited light. An optical recording technique for use with the card employs data pits which are formed on an optical reflective surface of an optical recording layer. The thus formed data pits are detected by difference in optical reflectivity from the data pits when the object is illuminated by laser beam so that data are read. The card is constituted by adhering a card front substrate to a card rear substrate, and hologram and optical recording portion are formed between the card front substrate and the card rear substrate. The certification card is difficult to falsify and alter and, therefore, has high safety.

Abstract: This optical recording card includes optical recording medium which is formed with optical information patterns each of which has an optical reflective layer and information stored in the optical recording card can be read out in dependency on the difference in optical reflectivity of the optical information pattern. It is not economical that the optical reflective layer of the optical recording card is formed on a base sheet by etching or the like, wherein the base sheet is prepared in the form of a sheet. The optical recording card is produced by way of the steps of forming an optical reflective layer on a continuous base film having large area and then die cutting the assembly of optical reflective layer and base film into a large number of optical recording cards having required dimensions in such a state that the optical recording medium is held between a card base and a protective sheet.

Abstract: The present invention is concerned with a certification card such as ID card or the like including hologram and an optical recording portion.Hologram is such that an amplitude and a phase of light wave emitted from an object are recorded and an image of the object is rebuilt by emitting light to reproduce of an amplitude and a phase of the thus emitted light.On the other hand, optical recording technique is such that data pits are formed on an optical reflective surface of an optical recording layer and the thus formed data pits are detected by difference in optical reflectivity from the data pits when the object is lightened by laser beam so that data are read.According to the present invention a card is constituted by adhering a card front board to a card rear board, and hologram and optical recording portion are formed between the card front board and the card rear board.The such prepared certification card is difficult to be falsified and altered and therefore it has high safety.

Abstract: An improved art of producing an optical recording medium by utilizing a photo-etching technique is disclosed. Pits pattern of address for guide groove and sector on each of tracks of optical recording medium to be preformatted is formed in accordance with a photo-etching process or a resist lift-off process. A film of optical recording medium is formed on a transparent base plate and it is then subjected to photo-etching process or alternatively to resist lift-off process to form preformatted pits pattern.