Abstract: A medium 1, that is a laminated holographic medium of the present invention is composed of two or more core layers 2; 3 or more cladding layers 3 set so as to bind the core layers 2; one or more diffraction grating layers 4 storing information data and set at a boundary between a portion of the core layers 2 and the cladding layers 3 binding the core layers 2 or set inside the core layers 2; and one or more recording layers 42 storing information data as forms or a refractive index distribution and set at a boundary between a portion of the core layers 2 and the cladding layers 3 binding the core layers 2 or inside the core layers 2 through or without a gap layer.

Abstract: An information coding apparatus, an information decoding apparatus, and a method and a program therefor are provided, which can represent a large amount of information with a small number of pixels. Information bits which are inputted are coded as a block of a two-dimensional image made up from m (where m is a natural number)×n (where n is a natural number) pixels. Specifically, pixels which represent the information bits are arranged in a code area, which is an area of (m?o)×(n?p) pixels within a code block of m×n pixels (where o and p are natural numbers which satisfy 0<o<m and 0<p<n); and, no pixels which represent the information bits are arranged in a guide area, which is an area of the other pixels within the code block of m×n pixels.

Abstract: A magneto-optical recording medium has a recording layer and a reflective layer on a substrate. The recording layer has a layered structure in which at least one spinel ferrite (or rutile-type oxide or hematite) layer and at least one garnet ferrite layer are piled together. It is preferable that the layered structure is formed on tracks where data are recorded. A manufacturing method comprises the steps of heat treatment in the range of 500-700° C., preferably 600-630° C., after the formation of the recording layer. In the magneto-optical recording and playback device to record and play back data, the wavelength of light for recording data is different from that for reading data, which is preferable for a magneto-optical recording medium comprising a garnet ferrite layer.

Abstract: A medium 1, that is a laminated holographic medium of the present invention is composed of two or more core layers 2; 3 or more cladding layers 3 set so as to bind the core layers 2; one or more diffraction grating layers 4 storing information data and set at a boundary between a portion of the core layers 2 and the cladding layers 3 binding the core layers 2 or set inside the core layers 2; and one or more recording layers 42 storing information data as forms or a refractive index distribution and set at a boundary between a portion of the core layers 2 and the cladding layers 3 binding the core layers 2 or inside the core layers 2 through or without a gap layer.

Abstract: This invention relates to magneto-optical recording media such as magneto-optical disks and cards, manufacturing methods of the medium and a magneto-optical recording and playback device to record and play back data using the magneto-optical recording media. The magneto-optical recording medium of the present invention has a recording layer and a reflective layer on a substrate, and the recording layer has a layered structure in which at least one spinel ferrite (or rutile-type oxide or hematite) layer and at least one garnet ferrite layer are piled together. It is preferable that the layered structure is formed on tracks where data are recorded. The manufacturing method of the present invention comprises the steps of heat treatment in the range of 500-700° C., preferably 600-630° C., after the formation of the recording layer.

Abstract: In a two dimensional image recording and reproducing scheme, a position of a prescribed pattern in an information recording image that contains the prescribed pattern is detected by detecting a rough position of the prescribed pattern in the information recording image in units of pixel size, and then detecting a detailed position of the prescribed pattern in the information recording image in units less than the pixel size, according to the rough position and a center of gravity of a distribution of similarities between regions in the information recording image and a reference image of the prescribed pattern.

Abstract: A holographic medium is formed of an optical waveguide including at least one core layer positioned between at least one portion of a material having a lower refractive index, a diffraction grating layer formed at a boundary between the core layer and the material of lower refractive index or in the core layer, and a storage layer outside the optical waveguide. Upon storing information in the storage layer a reference beam and an object are input into the optical waveguide and in retrieving stored information the reference beam is emitted to an end face of the core layer and transmitted through the core layer to be transformed into a diffracted beam in a diffraction grating layer that is emitted outside the core layer and transmitted through the storage layer, where the object beam is retrieved as a retrieved beam.

Abstract: An information coding apparatus, an information decoding apparatus, and a method and a program therefor are provided, which can represent a large amount of information with a small number of pixels. Information bits which are inputted are coded as a block of a two-dimensional image made up from m (where m is a natural number)×n (where n is a natural number) pixels. Specifically, pixels which represent the information bits are arranged in a code area, which is an area of (m?o)×(n?p) pixels within a code block of m×n pixels (where o and p are natural numbers which satisfy 0<o<m and 0<p<n); and, no pixels which represent the information bits are arranged in a guide area, which is an area of the other pixels within the code block of m×n pixels.

Abstract: This invention relates to magneto-optical recording media such as magneto-optical disks and cards, manufacturing methods of the medium and a magneto-optical recording and playback device to record and play back data using the magnetic-optical recording media. The magneto-optical recording medium has a recording layer and a reflective layer on a substrate, and the recording layer has a layered structure in which at least on spinel ferrite (or rutile-type oxide or hematite) layer and at least one garnet ferrite layer are piled together. The manufacturing method comprises the steps of heat treatment after the formation of the recording layer. In the magneto-optical recording and playback device to record and playback data, the wavelength of light for recording data is different from that for reading data, which is preferable for a magneto-optical recording medium comprising a garnet ferrite layer.

Abstract: This invention relates to magneto-optical recording media such as magneto-optical disks and cards, manufacturing methods of the medium and a magneto-optical recording and playback device to record and play back data using the magneto-optical recording media. The magneto-optical recording medium of the present invention has a recording layer and a reflective layer on a substrate, and the recording layer has a layered structure in which at least one spinel ferrite (or rutile-type oxide or hematite) layer and at least one garnet ferrite layer are piled together. It is preferable that the layered structure is formed on tracks where data are recorded. The manufacturing method of the present invention comprises the steps of heat treatment in the range of 500-700° C., preferably 600-630° C., after the formation of the recording layer.

Abstract: An information reading apparatus can detect the coupling state of the input light to a waveguide of a laminated recording medium in a simple manner, so as to enable to focus the input light on a target recording layer to access the information recorded in the target recording layer quickly. The apparatus is compact and is economical to produce. The apparatus has a light source for injecting a light on an input edge of a lamination recording section, assembled into the recording medium containing a lamination of recording layers. Each recording layer has data represented by scattering centers which diffract an input light generated by a converging lens. An input light directing device directs the light source and the converging lens as a unit to focus the input light on a desired location. An image recording device records an informational image generated by guided waves produced within a laminated waveguide.

Abstract: In a two dimensional image recording and reproducing scheme, a position of a prescribed pattern in an information recording image that contains the prescribed pattern is detected by detecting a rough position of the prescribed pattern in the information recording image in units of pixel size, and then detecting a detailed position of the prescribed pattern in the information recording image in units less than the pixel size, according to the rough position and a center of gravity of a distribution of similarities between regions in the information recording image and a reference image of the prescribed pattern.

Abstract: A holographic medium comprising an optical waveguide including at least one core layer positioned between portions having a lower refractive index; a diffraction grating layer formed at a boundary between the core layer and the above portions or in the core layer; and a storage layer outside the optical waveguide. An optical waveguide having the above structure in which the diffraction efficiency of the diffraction grating layer has a specific distribution is useful. In multiple-angle storage, a reference beam is emitted from an end face of a core layer or from the upper or lower side of the medium and a photodetector may be used, so as to control the incident angle. The reference beam and/or the optical waveguide is moved so that the reference beam couples only with a specific diffraction grating layer. The object beam may be focused onto a small target area of the storage layer.

Abstract: The present invention provides a data readout apparatus and method using optical beams by which high data-recording density for optical recording media and high transfer rate for regenerated data can be realized.