Abstract: Aluminum nitride crystal particles, aluminum nitride powders containing the same, production processes for both of them, an organic polymer composition comprising the aluminum nitride crystal particles and a sintered body. Each of the aluminum nitride crystal particles has a flat octahedral shape in a direction where hexagonal faces are opposed to each other, which is composed of two opposed hexagonal faces and 6 rectangular faces, in which the average distance “D” between two opposed corners of each of the hexagonal faces is 3 to 110 ?m, the length “L” of the short side of each of the rectangular faces is 2 to 45 ?m, and L/D is 0.05 to 0.8; each of the hexagonal faces and each of the rectangular faces cross each other to form a curve without forming a single ridge; and the true destiny is 3.20 to 3.26 g/cm3.

Abstract: After a wet blasting treatment for jetting a slurry, which contains spherical alumina as abrasive grains in a liquid, to the surface of a ceramic substrate 10 of aluminum nitride sintered body so that the ceramic substrate 10 has a residual stress of not higher than ?50 MPa and so that the surface of the ceramic substrate 10 to be bonded to the metal plate 14 has an arithmetic average roughness Ra of 0.15 to 0.30 ?m, a ten-point average roughness Rz of 0.7 to 1.1 ?m and a maximum height Ry of 0.9 to 1.

Abstract: Aluminum nitride crystal particles, aluminum nitride powders containing the same, production processes for both of them, an organic polymer composition comprising the aluminum nitride crystal particles and a sintered body. Each of the aluminum nitride crystal particles has a flat octahedral shape in a direction where hexagonal faces are opposed to each other, which is composed of two opposed hexagonal faces and 6 rectangular faces, in which the average distance “D” between two opposed corners of each of the hexagonal faces is 3 to 110 ?m, the length “L” of the short side of each of the rectangular faces is 2 to 45 ?m, and L/D is 0.05 to 0.8; each of the hexagonal faces and each of the rectangular faces cross each other to form a curve without forming a single ridge; and the true destiny is 3.20 to 3.26 g/cm3.

Abstract: After a wet blasting treatment for jetting a slurry, which contains spherical alumina as abrasive grains in a liquid, to the surface of a ceramic substrate 10 of aluminum nitride sintered body so that the ceramic substrate 10 has a residual stress of not higher than ?50 MPa and so that the surface of the ceramic substrate 10 to be bonded to the metal plate 14 has an arithmetic average roughness Ra of 0.15 to 0.30 ?m, a ten-point average roughness Rz of 0.7 to 1.1 ?m and a maximum height Ry of 0.9 to 1.

Abstract: A method for manufacturing a ceramic substrate having a via hole(s) and a surface wiring pattern electrically connected to the via hole(s). The method includes: preparing a sintered ceramic substrate having a via hole(s); forming over the sintered ceramic substrate a sintered ceramic layer having a hole(s) or opening(s) whose bottom is configured to be at least a part of an exposed end surface of the via hole(s) by post-firing method; forming inside the hole(s) or opening(s) a conductive portion which electrically connects the surface of the sintered ceramic layer and the via hole(s); and forming over the surface of the sintered ceramic layer a surface wiring pattern electrically connected to the conductive portion.

Abstract: A method for manufacturing a ceramic substrate having a via hole(s) and a surface wiring pattern electrically connected to the via hole(s). The method includes: preparing a sintered ceramic substrate having a via hole(s); forming over the sintered ceramic substrate a sintered ceramic layer having a hole(s) or opening(s) whose bottom is configured to be at least a part of an exposed end surface of the via hole(s) by post-firing method; forming inside the hole(s) or opening(s) a conductive portion which electrically connects the surface of the sintered ceramic layer and the via hole(s); and forming over the surface of the sintered ceramic layer a surface wiring pattern electrically connected to the conductive portion.

Abstract: A sintered ceramics for mounting a light-emitting element, which is capable of realizing high optical reflectance over the entire region from ultraviolet radiation to visible light. The sintered ceramics has a light-reflective face of which reflectance to light in each wavelength in the range of 250 nm˜750 nm is 70% or more. The light-reflective face satisfies following reaction: |RA?RB|?20 when reflectance to light of 750 nm is defined as RA%, and reflectance to light of 300 nm is defined as RB. The sintered ceramics has not layer to be peeled from the light-reflective face when a Tape Peeling Test is carried out to the light-reflective face in accordance with the method described in JIS H8504 (1990).

Abstract: A portable information terminal device cradle apparatus includes a recording/reproducing apparatus for recording and reproducing data using a recording disk, disposed in an inner space enclosed by an enclosure including an upper plate and a lower plate, a main part of a connector for a connection with a portable information terminal device and/or a cradle assembly placed on the upper plate, and a connector holding part for holding the main part of the connector such that the main part of the connector is rotatable with respect to the upper plate.

Abstract: A portable information terminal device cradle apparatus includes a recording/reproducing apparatus for recording and reproducing data using a recording disk, disposed in an inner space enclosed by an enclosure including an upper plate and a lower plate, a main part of a connector for a connection with a portable information terminal device and/or a cradle assembly placed on the upper plate, and a connector holding part for holding the main part of the connector such that the main part of the connector is rotatable with respect to the upper plate.

Abstract: A memory cartridge having a plurality of dynamic memory units includes an access conversion circuit which converts a static access signal into its inverted signal and an access control circuit which controllably switches between a signal for refreshing each dynamic unit and a signal for external access. The memory cartridge also includes a power switching circuit which switches power from an internal power supply to an external power supply when the memory cartridge is mounted to an external device.

Abstract: An optical head has a stationary optical system and a movable optical system. The stationary optical system includes a semiconductor laser located in a holding member with an opening, and a beam splitter for guiding light emitted from the light source, to the outside of the holding member through the opening. The sheet member contacts both the beam splitter and that portion of the holding member which surrounds the opening thereof, thereby sealing the opening. Further, the holding member is movably secured to the frame of the movable optical system.

Abstract: A memory cartridge having a plurality of dynamic memory units includes an access conversion circuit which converts a static access signal into its inverted signal and an access control circuit which controllably switches between a signal for refreshing each dynamic unit and a signal for external access. The memory cartridge also includes a power switching circuit which switches power from an internal power supply to an external power supply when the memory cartridge is mounted to an external device.

Abstract: A photomagnetic signal detecting apparatus, in the reflected light path of a light beam reflected from a recording medium in which information is magnetically recorded, there is provided an optical element having a light beam dividing device transmitting one of two polarized lights intersecting at right angles with each other and reflecting the other polarized light and a light path converting device emitting by reflection or refraction the light beam reflected by this light beam dividing device in substantially the same direction as of the transmitted light transmitted through the above mentioned light beam dividing device so that the transmitted light and reflected light emitted from this optical element may be received by a photodetecting device.

Abstract: A semiconductor file memory has a semiconductor memory connected to an information processor and operated to store data transferred from the information processor and read out stored data, the file memory comprising a serial/parallel conversion circuit which receives, in a serial manner, data to be stored in the semiconductor memory and converts the data line parallel data, a parallel/serial conversion circuit which receives data read out of the semiconductor memory and converts the data into serial data, and an address data holding circuit which holds address data transferred from the information processor, the serial data transferred from the information processor being converted into parallel data by the serial/parallel conversion circuit and the converted data stored in the semiconductor memory in accordance with addresse data held in the address data holding circuit, and parallel data stored in the semiconductor memory is read out in accordance with address data held in the address data holding circuit,

Abstract: A semiconductor file memory, intended for use as an external memory of an information processor such as an arithmetic processor, including an interface for transacting data with the information processor, a plurality of memory units each including semiconductor memory devices mounted on a substrate and having identical terminal assignments in connection commonly to a bus of the interface through a connector, a control circuit unit having identical terminal assignments for the connectors of the memory units and operating to control the memory units by taking the place of at least one of the memory units, and a selection circuit for selecting a memory unit or control circuit unit out of the memory units and the control unit which has taken the place of the memory unit in response to signal from the interface.