Abstract: The present invention proposes an optical head apparatus provided with light-blocking structure that can reliably prevent nonessential light from reaching the photo detector, without being an impediment to miniaturization and flattening, moreover, without increasing manufacturing cost. In an optical head apparatus, and in a lens holder, light-blocking section is provided that blocks nonessential light from passing outside the effective diameter of objective lens. This light-blocking section is constructed so that it extends only in tracking direction T of objective lens 5. Further, light-blocking face of light-blocking section slants at an angle of 1° or more toward the face orthogonal to the optical axis, consequently, nonessential light is reflected in a direction other than the direction of photo detector.

Abstract: The present invention proposes an optical head apparatus provided with light-blocking structure that can reliably prevent nonessential light from reaching the photo detector, without being an impediment to miniaturization and flattening, moreover, without increasing manufacturing cost. In an optical head apparatus, and in a lens holder, light-blocking section is provided that blocks nonessential light from passing outside the effective diameter of objective lens. This light-blocking section is constructed so that it extends only in tracking direction T of objective lens 5. Further, light-blocking face of light-blocking section slants at an angle of 1° or more toward the face orthogonal to the optical axis, consequently, nonessential light is reflected in a direction other than the direction of photo detector.

Abstract: An optical head device includes a lens holder holding an objective lens and a magnetic drive mechanism for driving the lens holder in a tracking direction and a focusing direction. The magnetic drive mechanism includes a plurality of drive coils mounted on the lens holder and a drive magnet facing the drive coils on a frame. The plurality of drive coils are formed with a continuous coil wire such that a plurality of mid-portions of the continuous coil wire are wound around to form the plurality of drive coils that are electrically connected in series. A coil manufacturing apparatus includes a plurality of winding core parts each of which includes a protrusion part around which the continuous coil wire is wound and a base portion which gives a winding start position for the continuous coil wire. The plurality of winding core parts being constructed such that the respective base portions of the winding core parts are set to be successively higher by a size substantially the same as the thickness of the coils.

Abstract: A grating mounting section 10 for mounting a laser diode 3 and a diffraction grating element 8 is formed in a frame body 2 of an optical pickup device. The diffraction grating element 8 includes a main body 83 provided with a grating face 82, a holder 84 being integral with the main body 83 while surrounding the same, and an arm portion 81 protruded outward from the outer circumferential face of the holder 84 as viewed in the radial direction. The arm portion 81 is protruded outward through a groove 22 formed in the grating mounting section 10 of the frame body side. An angular position adjustment of the diffraction grating element 8 can be carried out by turning the arm portion 81 about the optical axis.

Abstract: A system for positioning a movable body for a processing machine. A lead screw is rotatably and axially shiftably supported and engaged with the movable body. The lead screw is rotated by a motor to move the movable body. A hydrostatic thrust bearing is provided for preventing axial movement of the lead screw. The lead screw is finely moved in the axial direction by controlling the pressure difference of oil supplied to the thrust bearing to position the movable body.

Abstract: A grinding machine including optical detectors for detecting an inclination and a difference of a reference position of the workpiece with respect to a reference position of the grinding machine; an inclinable jig capable of inclining the reference position of the workpiece; controlling members for rotating the inclinable jig; displacement detectors for detecting an inclination of the inclinable jig; and a controlling device for calculating the correction amount of the reference position of the workpiece according to the position information from the optical detectors, providing the control signal to the controlling members in accordance with the calculated value to rotate the inclinable jig, simultaneously receiving the information from the displacement detectors, rotating the inclinable jig until the information from the displacement detectors coincides with the calculated value, and holding the jig.

Abstract: A measuring device for oblique angle which is wide in the range of measurement and is high in measuring accuracy, wherein an oblique table is controlled in such a way that the oblique table static-pressure supported is subjected to servo-control so that a detection signal of an oblique angle detector is zero, and an oblique angle is measured by the control signal.

Abstract: A grinding machine comprising a tool mounting head which is movable vertically between a pair of guide columns on which guide surfaces are provided for guiding the head. A plurality of workpieces are mounted on corresponding holding jigs which are mounted by means enabling them to be tilted, and measurement means such as X-ray or optical means are provided to sense the orientation of a workpiece being machined, with signals from the measurement means controlling the tilting of the corresponding holding jig. Jigs are mounted on a rotary table rotatably mounted on a workpiece slide which can be traversed below a grinding tool.

Abstract: In a machine tool such as a surface grinding machine or the like, a guide mechanism for the machine tool wherein one of a pair of opposed guideways is formed into a hydrodynamic guideway, whilst the other guideway is formed into a hydrostatic guideway, the hydrodynamic guideway is utilized as only one master guide, and on the other hand, the hydrostatic guideway is made to act in such that a moving body is pushed onto the hydrodynamic guideway with a constant pressure, so that this arrangement makes uniform the contact pressure distribution in the hydrodynamic guideway, thus the posture of the moving body is improved thereby making the same to perform precision linear motion.

Abstract: An apparatus is disclosed which enables a controlled member (e.g. a workpiece retaining member in a jig) to be adjusted in position by extremely small amounts of linear displacement or angular rotation, with a very high degree of accuracy and static and dynamic stability. The apparatus is based on a servo system controlled by electrical signals and employs hydrostatic pads to support and move the controlled member.

Abstract: A machine tool elevating and guiding apparatus comprising a tool mounting head which is movable vertically between a pair of guide columns. Guide surfaces on the guide columns are positioned closely adjacent to guided surfaces on the tool mounting head and a flow of pressurized fluid is passed at a fixed pressure between the guide and guided surfaces, such as to eliminate tilting of the tool mounting head. At least one guide surface serves as a reference surface, with a thin film of pressurized lubricating oil being formed between this and an adacent guided surface. The tool mounting head is mounted on an elevating feed screw, with means provided whereby the weight of the head is supported independently of that screw, so that a very high degree of precision in vertical positioning of the tool mounting head is attained.