Abstract: To provide a carbon fiber Ti—Al composite material having hardness, heat resistance and abrasion resistance, having reduced weight and improved strength and thermal conductivity and being excellent in uniformity of the quality. A carbon fiber Ti—Al composite material which is prepared by pressure impregnating a molded product containing fine carbon fibers having a fiber diameter of from 0.5 to 500 nm and a fiber length of at most 1,000 ?m and having a hollow-structured central axis and a titanium powder or a titanium oxide powder, with aluminum or an aluminum alloy by molten metal forging.

Abstract: To provide a carbon fiber Ti—Al composite material having hardness, heat resistance and abrasion resistance, having reduced weight, improved strength, elastic modulus and thermal conductivity and being excellent in the uniformity of the quality. A carbon fiber Ti—Al composite material which is prepared by pressure impregnating a molded product containing fine carbon fibers having a fiber diameter of from 0.5 to 500 nm and a carbon length of at most 1,000 ?m and having a hollow-structured central axis, carbon long fibers having a fiber diameter of from 5 to 15 ?m and a titanium powder or a titanium oxide powder, with aluminum or an aluminum alloy by molten metal forging.

Abstract: To provide a fine carbon fiber/metal composite material having high mechanical strength, a high thermal conductivity and a low coefficient of thermal expansion and suitable as a substrate for an electronic device. A fine carbon fiber/metal composite material, which is prepared by pressure impregnating a molded product containing fine carbon fibers having a fiber diameter of from 0.5 to 500 nm and a fiber length of at most 1,000 ?m, having a multilayer structure wherein cylindrical carbon layers overlap one another, and having a hollow-structured central axis, with aluminum, magnesium, copper or an alloy of such a metal, by molten metal forging.

Abstract: To provide a novel process for producing a unidirectional carbon fiber reinforced carbon composite material having all of high thermal conductivity, low thermal expansion properties and high strength, useful as e.g. a semiconductor heatsink. Carbon fibers are impregnated with a liquid for impregnation prepared by dispersing or dissolving powdery carbon, fine carbon fibers having a fiber diameter of from 0.5 to 500 nm and a fiber length of at most 1,000 ?m and having a hollow-structured central axis and a thermosetting resin in a medium, and the carbon fibers are molded, cured and then carbonized so that they are aligned in one direction.

Abstract: To provide a fine carbon fiber/metal composite material having high mechanical strength, a high thermal conductivity and a low coefficient of thermal expansion and suitable as a substrate for an electronic device. A fine carbon fiber/metal composite material, which is prepared by pressure impregnating a molded product containing fine carbon fibers having a fiber diameter of from 0.5 to 500 nm and a fiber length of at most 1,000 ?m, having a multilayer structure wherein cylindrical carbon layers overlap one another, and having a hollow-structured central axis, with aluminum, magnesium, copper or an alloy of such a metal, by molten metal forging.

Abstract: To provide a carbon fiber Ti—Al composite material having hardness, heat resistance and abrasion resistance, having reduced weight and improved strength and thermal conductivity and being excellent in uniformity of the quality. A carbon fiber Ti—Al composite material which is prepared by pressure impregnating a molded product containing fine carbon fibers having a fiber diameter of from 0.5 to 500 nm and a fiber length of at most 1,000 ?m and having a hollow-structured central axis and a titanium powder or a titanium oxide powder, with aluminum or an aluminum alloy by molten metal forging.

Abstract: To provide a carbon fiber Ti—Al composite material having hardness, heat resistance and abrasion resistance, having reduced weight, improved strength, elastic modulus and thermal conductivity and being excellent in the uniformity of the quality. A carbon fiber Ti—Al composite material which is prepared by pressure impregnating a molded product containing fine carbon fibers having a fiber diameter of from 0.5 to 500 nm and a carbon length of at most 1,000 ?m and having a hollow-structured central axis, carbon long fibers having a fiber diameter of from 5 to 15 ?m and a titanium powder or a titanium oxide powder, with aluminum or an aluminum alloy by molten metal forging.

Abstract: An optical disk apparatus includes a tilt detection unit detecting the tilt value of an optical disk medium with respect to an optical system. A tilt compensation unit compensates for the tilt of the optical disk medium by adjusting a relative angle between the optical system and the optical disk medium according to the tilt value detected by the tilt detection unit. A tilt detection error estimation unit estimates tilt detection error of the tilt detection unit with respect to a radial position of the optical disk medium at which information is recorded/reproduced by the optical systems by referring to tilt values that are previously detected at a plurality of radial positions of the optical disk medium by the tilt detection unit. The tilt compensation unit has a correction unit that corrects the tilt value according to the tilt detection error estimated by the tilt detection error estimation unit.

Abstract: A data recording/reproduction apparatus is provided, which apparatus includes a spindle motor which is held by a base body and rotates an optical disk, an optical pickup which projects a laser beam into a spot on the optical disk for data recording/reproduction, first and second support mechanisms provided on the base body, and a seek mechanism which is held by the first and second support mechanisms so as to be freely tilted with respect to the base body and actuates the optical pickup in radial directions of the optical disk. The first support mechanism is vertically movable in directions of a thickness of the optical disk so that a tilt of the optical pickup with respect to the optical disk is adjusted.

Abstract: A data recording/reproduction apparatus is provided, which apparatus includes a spindle motor which is held by a base body and rotates an optical disk, an optical pickup which projects a laser beam into a spot on the optical disk for data recording/reproduction, first and second support mechanisms provided on the base body, and a seek mechanism which is held by the first and second support mechanisms so as to be freely tilted with respect to the base body and actuates the optical pickup in radial directions of the optical disk. The first support mechanism is vertically movable in directions of a thickness of the optical disk so that a tilt of the optical pickup with respect to the optical disk is adjusted.

Abstract: An optical disk apparatus includes a tilt detection unit detecting the tilt value of an optical disk medium with respect to an optical system. A tilt compensation unit compensates for the tilt of the optical disk medium by adjusting a relative angle between the optical system and the optical disk medium according to the tilt value detected by the tilt detection unit. A tilt detection error estimation unit estimates tilt detection error of the tilt detection unit with respect to a radial position of the optical disk medium at which information is recorded/reproduced by the optical systems by referring to tilt values that are previously detected at a plurality of radial positions of the optical disk medium by the tilt detection unit. The tilt compensation unit has a correction unit that corrects the tilt value according to the tilt detection error estimated by the tilt detection error estimation unit.

Abstract: A data recording/reproduction apparatus is provided, which apparatus includes a spindle motor which is held by a base body and rotates an optical disk, an optical pickup which projects a laser beam into a spot on the optical disk for data recording/reproduction, first and second support mechanisms provided on the base body, and a seek mechanism which is held by the first and second support mechanisms so as to be freely tilted with respect to the base body and actuates the optical pickup in radial directions of the optical disk. The first support mechanism is vertically movable in directions of a thickness of the optical disk so that a tilt of the optical pickup with respect to the optical disk is adjusted.