Abstract: The present invention makes it possible to acquire image information required for displaying a three-dimensional image of an object in a space with a simple configuration and to achieve display of a stereoscopic dynamic image in a true sense with a simple configuration. Light from an object (10) impinges upon a deflecting plate (11). Among the incident beams of light, the deflecting plate (11) allows beams of light at a predetermined angle to the plane of the deflecting plate (11) to pass, the beams exiting as parallel beams of light perpendicular to the plane of the deflecting plate (11). The light passes through a converging lens (12), a pinhole member (13), and a converging lens (14) to impinge upon a CCD (15). An angle of incident light selected by the deflecting plate (11) is sequentially changed as time passes.

Abstract: In a servo operation, position-controlling light, which is red light, is projected onto a recording medium so as to converge to a minimum diameter on a reflecting surface of the recording medium. In a recording operation, information light and recording-specific reference light, each of which is green light, are projected coaxially onto one side of an information recording layer of the recording medium so as to converge to a minimum diameter at an identical position located off the reflecting surface. Information is recorded in the information recording layer in the form of an interference pattern resulting from interference between the information light yet to impinge on the reflecting surface and the recording-specific reference light reflected by the reflecting surface and an interference pattern resulting from interference between the recording-specific reference light yet to impinge on the reflecting surface and the information light reflected by the reflecting surface.

Abstract: An optical disc recording medium of the present invention comprises a first substrate (11) having a physically pre-formatted surface; a reflective film (12) formed on the pre-formatted surface of the first substrate (11); a transparent layer (13) with a thickness of 50-430 ?m formed on the reflective film (12); a second substrate (15) composed of transparent material and located at a distance of certain spacing from the transparent layer (13); and a recording layer (14) for hologram recording filled between the transparent layer (13) and the second substrate (15).

Abstract: Image information necessary to display a three-dimensional image of an object in a space is acquired with a simple structure, and a three-dimensional dynamic image in a true sense is displayed with a simple structure. Part of light from an object (10) falls on a polarizer (11). The polarizer (11) passes the component of the incident light polarized at a predetermined angle to the surface of the polarizer (11) and allows the component to emerge from the polarizer (11) as parallel light perpendicular to the surface of the polarizer (11). The parallel light passes through a condenser lens (12), a pinhole member (13), and a condenser lens (14) and falls on a CCD (15). The angle of incident light selected by the polarizer (11) can be changed with time. Therefore, the image information outputted from the CCD (15) is a set of items of two-dimensional image information including the direction of imaging changing with time and is necessary to display a three-dimensional image of an object in a space.

Abstract: The present invention makes it possible to acquire image information required for displaying a three-dimensional image of an object in a space with a simple configuration and to achieve display of a stereoscopic dynamic image in a true sense with a simple configuration. Light from an object (10) impinges upon a deflecting plate (11). Among the incident beams of light, the deflecting plate (11) allows beams of light at a predetermined angle to the plane of the deflecting plate (11) to pass, the beams exiting as parallel beams of light perpendicular to the plane of the deflecting plate (11). The light passes through a converging lens (12), a pinhole member (13), and a converging lens (14) to impinge upon a CCD (15). An angle of incident light selected by the deflecting plate (11) is sequentially changed as time passes.

Abstract: An optical-disk recording method, recording apparatus and reproducing apparatus are provided which are capable of continuously recording/reproducing a hologram with ultra-high density. In the case of recording a hologram to a holographic recording area, a holographic recording spot HSP on one track of the holographic recording area and a holographic recording spot HSP on a track adjacent thereto are recorded in circumferentially different positions. At least one holographic recording spot HSP is formed on each track, making the process continuous. Recording is made such that, provided that the holographic recording spot HSP has a diameter D and a multiplex number of holographic recording spots HSP is m, a pitch P between adjacent holographic recording spots HSP is P=D/m. Consequently, it is possible to efficiently record a hologram with density to a holographic recording area of an optical disk recording medium, and to achieve the density increase of holographic recording capacity.

Abstract: In a servo operation, position-controlling light, which is red light, is projected onto a recording medium so as to converge to a minimum diameter on a reflecting surface of the recording medium. In a recording operation, information light and recording-specific reference light, each of which is green light, are projected coaxially onto one side of an information recording layer of the recording medium so as to converge to a minimum diameter at an identical position located off the reflecting surface. Information is recorded in the information recording layer in the form of an interference pattern resulting from interference between the information light yet to impinge on the reflecting surface and the recording-specific reference light reflected by the reflecting surface and an interference pattern resulting from interference between the recording-specific reference light yet to impinge on the reflecting surface and the information light reflected by the reflecting surface.

Abstract: An optical information recording device for recording information utilizing holography comprises a recording medium moving means for moving a recording medium, a follow-up control circuit for controlling an irradiation position, and a signal converting means for obtaining a reproduction signal from an address servo-control area including a light source for radiating an information beam and a reference beam onto the recording medium. The follow-up control circuit is composed of a binary-coding means for binary-coding the reproduction signal and a follow-up signal circuit, and detects the travel amount of the irradiation position moving means and generates, according to the travel amount detected and for a specific time during which the irradiation position of the information beam and the reference beam follows, an irradiation position control signal for controlling an irradiation position moving in one information recording area through an output terminal of a gain control amplifier.

Abstract: Spherical graphite cast iron utilized to prepare a lapping tool is manufactured by casting a molten composition into a mold cavity, and by chilling one side of the resulting casting thereby causing unidirectional solidification, the one side being used as the operating surface of the lapping tool. The molten composition consists of 3.0-3.8 wt. % of carbon, 2.0-2.9 wt. % of silicon, 0.3-0.9 wt. % of manganese, less than 0.05 wt. % of phosphorus, less than 0.03 wt. % of sulfur, 0.2-1.0 wt. % of nickel, 0-0.8 wt. % of copper, 0.05-0.5 wt. % of molybdenum, 0.03-0.09 wt. % of magnesium and the balance of iron. The lapping tool made of this casting has a percentage of sphericity of higher than 80%, graphite particle diameter of less than 100 microns, a density of graphite particles of larger than 70/mm.sup.2, and a Vickers hardness of larger than 200.

Abstract: Spherical graphite cast iron utilized to prepare a lapping tool is manufactured by casting a molten composition into a mold cavity, and by chilling one side of the resulting casting thereby causing unidirectional solidification, the one side being used as the operating surface of the lapping tool. The molten composition consists essentially of 3.0-3.8 wt. % of carbon, 2.0-2.9 wt. % of silicon, 0.3-0.9 wt. % of manganese, less than 0.05 wt. % of phosphorus, less than 0.03 wt. % of sulfur, 0.2-1.0 wt. % of nickel, 0-0.8 wt. % of copper, 0.05-0.5 wt. % of molybdenum, 0.03-0.09 wt. % of magnesium and the balance of iron. The lapping tool made of this casting has a percentage of sphericity of higher than 80%, graphite particle diameter of less than 100 microns, a density of graphite particles of larger than 70/mm.sup.2, and a Vickers hardness of larger than 200.

Abstract: A polishing machine has an upper polishing plate and a lower polishing plate provided below the upper polishing plate. The upper polishing plate has slurry passages. Plugs for supplying slurry are detachably quick coupled to the slurry passages. A piece of polishing pad is bonded to the lower surface of the upper polishing plate. After a spent polishing pad has been removed and a fresh polishing pad has been attached to the lower surface of the upper polishing plate, a hole-cutter is downwardly inserted in each slurry passage until it pierces the fresh polishing pad, thus cutting a hole in the polishing pad.