Abstract: A first comparator (112a) compares a first voltage signal to a predetermined threshold to output a first binary signal corresponding to a comparison result. A second comparator (112b) compares a second voltage signal to a predetermined threshold to output a second binary signal corresponding to a comparison result. A first digital sampling section (113a) samples the first binary signal output by the first comparator 112a to generate a first sampling signal. A second digital sampling section (113b) samples the second binary signal output by the second comparator (112b) to generate a second sampling signal. A phase difference detector circuit (114) detects a phase difference between the first sampling signal generated by the first digital sampling section (113a) and the second sampling signal generated by the second digital sampling section (113b).

Abstract: The stem slide device of the present invention in an extruder has a stem vertical movement support (71) and slide guide members (72-1, 2) fastened to the support and forming guide grooves. A stem (6) pushing against a billet loaded in a container is held at the slide table (73) horizontally. The slide table slides in the vertical direction along the vertical face of the support. When the slide table is positioned at the bottom end of the guide groove, the hydraulic cylinders (77-1, 2) are driven so that the rods (78-1, 2) push the back surface of the slide table against the vertical face of the support. Therefore, the axis of the stem is held matched with the axis of the container.

Abstract: An output voltage of a cathode driving type semiconductor laser driving circuit is made minimum, power consumption of a driving circuit section is suppressed, and heat generation of an optical head or an optical disc device is reduced. In addition to the conventional constitution, the semiconductor laser driving circuit permits the output voltage of the semiconductor laser driving circuit to be at a prescribed level by measuring a cathode voltage (Vout) of a semiconductor laser (1) and controlling an anode voltage (Vld) so that the cathode voltage (Vout) is at the prescribed level, reduces power consumption of the driving circuit and suppresses temperature increase of the optical head or the optical disc device to be minimum.

Abstract: A stem slide apparatus comprises a stem slide base (73) with a stem (6) horizontally mounted thereon to press a billet (B) mounted on a container (5), a slide guide member (72, 72a, 72b) mounted on a vertical stem move support member (71) and formed with guide grooves in which the side end portions of the stem slide base are fitted and vertically slid, and a lock means (77a, 77b) arranged on the slide guide member to press the side end portions of the stem slide base. The stem slide apparatus further comprises a drive mechanism (10) having an electric motor (11) to move the slide base in the sliding direction. Therefore the indirect cause of a fire is removed and the maintenance work simplified.

Abstract: An optical information apparatus includes a laser which emits a light beam, an objective lens and the like which converge a light beam emitted from the laser on an optical recording medium, spherical aberration correction instrument which is arranged on an optical axis of the light beam which links the laser and the objective lens, and corrects a spherical aberration generated on the optical recording medium. Correction is performed so that outgoing power of the laser changes according to a correction amount by the spherical aberration correction instrument.

Abstract: The present invention provides an extrusion press and an extrusion control method capable of obtaining a uniformly-shaped extruded product by constantly applying a constant container sealing force between a container and a die even when an extrusion force varies during an extrusion process, improving product yield, and keeping a small energy consumption at the time of extrusion. A hydraulic pressure of a main cylinder device is detected, a deviation between the detected hydraulic pressure and a reference pressure set in advance is mathematically processed, and constant pressure extrusion is performed by correcting a container sealing force to reduce the container sealing force when the deviation is larger than the reference pressure, or to increase the container sealing force when the deviation is smaller than the reference pressure, so that a container sealing force corresponding to the reference pressure acts on the end surface of the die.

Abstract: A discard conveying apparatus comprising a chute provided below a die of an extrusion pressing machine in which discards are freely dropped along the chute through which the discards are guided, in which the discard conveying apparatus comprises a chute having a discharging port in a position which is approximately just under the dies, a bucket for containing the discards disposed in the discharging port of the chute, and a transporter capable of freely moving the bucket in a forward and backward direction, the transporter being attached to a machine base in the direction of crossing to an axis line of the machine base in the manner of being passed through the machine base and supporting an inversion axis of the bucket, and the bucket is turned and inversed when the bucket is transported to an end portion of the forward movement.

Abstract: The stem slide device of the present invention in an extruder has a stem vertical movement support (71) and slide guide members (72-1, 2) fastened to the support and forming guide grooves. A stem (6) pushing against a billet loaded in a container is held at the slide table (73) horizontally. The slide table slides in the vertical direction along the vertical face of the support. When the slide table is positioned at the bottom end of the guide groove, the hydraulic cylinders (77-1, 2) are driven so that the rods (78-1, 2) push the back surface of the slide table against the vertical face of the support. Therefore, the axis of the stem is held matched with the axis of the container.

Abstract: An extrusion molding method of an extrusion press includes a first step of loading a billet, the outer surface of which is subjected to a barking treatment, into a container, and extruding the billet in such a manner as to leave a predetermined length, a second step of loading a next billet into the container, additionally extruding the preceding billet with the succeeding billet in such a manner as to leave a predetermined length of the succeeding billet; and a third step of loading a next billet into the container and additionally extruding the preceding billet with the succeeding billet in such a manner as to leave a predetermined discard length of the succeeding billet and stopping extrusion. By way of these steps, the container does not move while maintaining contact with a die, and the billet is continuously extruded by leftover and additional extrusion.

Abstract: An aberration correction lens 4 is disposed in a space between a laser light source 3 and an objective lens 5, and a lens holder 10 is frictionally coupled to a drive shaft 7 via a frictional holding body 8. A piezoelectric element 6 is provided to one end of the drive shaft 7. The piezoelectric element 6 extends and contracts in response to an applied voltage. The lens holder 10 is moved relatively with respect to the drive shaft 7 in the drive shaft direction by varying a change rate when the applied voltage to the piezoelectric element 6 is increased and decreased.

Abstract: An optical disc controller of the present invention servo-controls an optical disc device which comprises a disc motor rotating an optical disc and an optical head emitting a light beam for recording data on the optical disc and/or reproducing data from the optical disc. The optical disc controller comprises: a variable clock output section for outputting a plurality of clock signals of different frequencies, and a control section which receives from the optical head a signal indicating a deviation from a predetermined target value to servo-control the light beam of the optical disc device and performs an operation according to the signal indicating the deviation so as to obtain and output a signal indicating a control amount.

Abstract: When a focus error signal (FE signal) is detected with an astigmatic method, a track crossing component leaks into the FE signal. Another detection method for the FE signal would reduce the leaking signal, but is not applicable when the light use efficiency decreases. An optical crosstalk correction amount determination unit (1000) determines a correction amount to correct an output of a tracking error detection unit (120) based on optical crosstalk from a TE signal to an FE signal occurring in reflection light from an optical disc (102) when a spot crosses a track. An output of the tracking error detection unit (120) is multiplied by the determined correction amount, and added to an output of the focus error detection unit (118). A focus control unit (138) executes focus control based on the addition result. This effectively reduces a TE signal component that leaks into the FE signal due to optical crosstalk.

Abstract: When a light-receiving element receives a first laser beam, an output power detection unit detects a differential quantum efficiency value of the first laser beam. A control unit judges whether or not an intensity filter and a filter driving unit are operated in accordance with a control signal output from the control unit by using the differential quantum efficiency value from the output power detection unit.

Abstract: An optical disc apparatus according to the present invention is usable for an optical disc including a bar code area and a control data area adjacent to the bar code area in a radial direction of the optical disc. The optical disc apparatus includes an optical head for directing an optical beam toward the optical disc so as to form an optical spot on the optical disc and output a signal in accordance with the optical beam reflected by the optical disc; a bar code area determination section for determining whether or not the optical spot is positioned on the bar code area of the optical disc based on the signal output by the optical head; and a control section for controlling the optical head so that the optical spot moves toward the control data area, when the optical spot is determined to be positioned on the bar code area.

Abstract: To provide an optical disc drive that can shift the focal point steadily to a focus controllable range. An optical disc drive includes: an optical branching element for splitting light from a light source into main and sub-beams; a condenser element for condensing the main and sub-beams; a photodetector section including photodetectors to receive reflected portions of the main and sub-beams, each photodetector having photosensitive areas, each of which outputs a signal representing the intensity of light received there; and a computing section for generating a first focus signal, representing where the focal point of the main beam is located with respect to the storage layer, based on the reflected light of the main beam, and a second focus signal based on the reflected light of the main and sub-beams.

Abstract: An optical disc drive includes a light source, a lens, a focusing section, a spherical aberration corrector, a focus signal generator, a gain calculator and a processor. The focusing section forms a beam spot in a focusing state on the information storage layer of an optical disc by controlling the position of the lens. The spherical aberration corrector changes a spherical aberration with the beam spot in a focusing state according to a drive value of a driving signal supplied to the spherical aberration corrector. The focus signal generator generates a focus signal representing the focusing state of the beam spot. The gain calculator calculates a loop gain of a focus control system in response to the focus signal. The processor determines the drive value for the spherical aberration corrector by the loop gain.

Abstract: When a spherical aberration generated on an optical recording medium is optically corrected, there has been a problem of irradiation power change of an output on an objective lens side due to a change of a signal level detected by a light quantity detector in response to the correction value.

Abstract: An extrusion molding method of an extrusion press includes a first step of loading a billet, the outer surface of which is subjected to a barking treatment, into a container, and extruding the billet in such a manner as to leave a predetermined length, a second step of loading a next billet into the container, additionally extruding the preceding billet with the succeeding billet in such a manner as to leave a predetermined length of the succeeding billet; and a third step of loading a next billet into the container and additionally extruding the preceding billet with the succeeding billet in such a manner as to leave a predetermined discard length of the succeeding billet and stopping extrusion. By way of these steps, the container does not move while maintaining contact with a die, and the billet is continuously extruded by leftover and additional extrusion.

Abstract: An optical disk apparatus comprises a focusing means for focusing a light beam on a recording medium having first and second information faces; means for moving a focal point of the light beam in a direction substantially perpendicular to the information faces of the recording medium; means for detecting a reflected light from the recording medium; means for detecting a focus condition of the light beam on the basis on an output signal from the reflected light detecting means; a focus control means for driving the focal point moving means on the basis of an output signal from the focus condition detecting means, and controlling the light beam so that the focus condition of the light beam becomes a prescribed focus condition; and a focus jumping means for moving the focal point of the light beam from the first information face to the second information face by driving the focal point moving means.

Abstract: An optical disc apparatus includes: a converging section for converging a light beam and irradiating a rotating information medium with the converged light beam; a moving section for moving the converging section, thereby moving a converging point of the converged light beam in a direction perpendicular to an information surface of the information medium; a converging state detection section for generating a focus servo signal which represents a converging state of the light beam on the information medium based on reflected light or transmitted light of the light beam from the information medium; a focus servo control section for controlling the moving section based on the focus servo signal, so that the light beam reaches a predetermined converging state on the information medium; and a focus pull-in section for turning ON the control by the focus servo control section, wherein the focus pull-in section turns ON the control by the focus servo control section in a case where the focus pull-in section determin