Abstract: When information is recorded or reproduced on or from an optical information medium having three or more recording layers using blue light, interference by another layer light is reduced and, when information is reproduced from an optical information medium using red light, an S/N ratio is held excellently high.

Abstract: Provided is an optical disk apparatus capable achieving stable focus control or tracking control. A first detector receives reflected light from an object lens optical system, a second detector receives reflected light from a prescribed information layer, a positional deviation determination unit determines positional deviation between a focal point of a light beam and a point where information on the prescribed information layer is recorded or reproduced, on the basis of a signal from the second detector, a stray light determination unit determines a surface stray light component which is reflected light from the surface of an optical disk and is included in the signal from the positional deviation determination unit, on the basis of the signal from the first detector, and a stray light correction unit corrects the signal output from the positional deviation determination unit on the basis of the surface stray light component thus determined.

Abstract: An optical disc recording apparatus (10) is provided with a tracking servo (13) for tracking a spiral track of concave and convex marks, an analog signal processor (14) for extracting a reproduction signal corresponding to the concave and convex marks, a digital signal processor (15) for extracting a channel clock synchronized with a channel bit length of the concave and convex marks, and a sub-information recording section (30) for recording sub-information by irradiating laser light based on the tracking to the spiral track. The sub-information recording section (30) records all the sub-information by repeating a process of recording a part of the sub-information by discretely irradiating laser light at a specified interval and with a specified frequency in synchronism with a channel clock by one tracking to form recordable marks on a reflective film a plurality of times.

Abstract: To provide a fully electric extrusion press to reduce power consumption, improve maintenability and operability, and eliminate an adverse effect on the environment. An extrusion press (10) comprises an end platen (1), a fixed platen (2) arranged at the rear thereof, a tie rod (4) configured to link the end platen and the fixed platen, a die (20), a container (3) loaded with a billet (8), an extrusion stem (13) configured to press the billet, a crosshead (7) attached with the extrusion stem, and an extrusion drive configured to reciprocate the extrusion stem. The extrusion drive comprises a rotatable wire drum (31) driven by an electric extrusion main motor (39) and drives the extrusion stem to perform extrusion molding by winding the wire (30) by rotating the wire drum.

Abstract: With a large capacity of an optical disk and high-speed recording, a frequency of a recording signal is increased and a pulse width is narrowed. In the case that a laser is driven by a signal having the short pulse width, unfortunately the high-speed recording is hardly performed to an optical disk when a rise time and a fall time of the optical pulse are lengthened. During user data recording, a bottom driving current is set to a second bottom driving current value that is a current value of a threshold or less, so that the rise time and the fall time of the optical pulse can be shortened to perform the high-speed recording of the optical disk.

Abstract: An extrusion press includes a container mover that moves a container at an end platen and molding a product by extruding a billet loaded in the container from a die by a stem driven by a main cylinder device, wherein the extrusion press includes a deflection amount detector that detects a deflection amount of the die; a deflection amount of the die during extrusion is detected; a deviation between the detected deflection amount and a reference deflection amount of the die set in advance is mathematically processed; and the extrusion press includes a controller that sends an output to the container mover to reduce a container sealing force when the deviation is minus, or increase the container sealing force when the deviation is plus so that a container sealing force corresponding to the reference deflection amount acts on an end surface of the die.

Abstract: When information is recorded or reproduced on or from an optical information medium having three or more recording layers using blue light, interference by another layer light is reduced and, when information is reproduced from an optical information medium using red light, an S/N ratio is held excellently high.

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: An object of this invention is to improve stability of tracking control and improve recording and reproduction performance. The tracking control device comprises a main push-pull signal generation section, which generates a main push-pull signal based on a signal obtained by photoelectric conversion of return light of the main beam; a microcomputer, which detects an other-layer stray light signal component included in a signal obtained by photoelectric conversion of return light of the sub-beam; a signal correction section, which corrects the signal obtained by photoelectric conversion of the return light of the sub-beam, based on the other-layer stray light signal component; and a sub-push-pull signal generation section, which generates a sub-push-pull signal based on the corrected signal obtained by photoelectric conversion of the return light of the sub-beam.

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 invention provides a tracking control device, a tracking control method, and an optical disc apparatus that enable to stably perform the tracking control, and reduce an influence of stray light from the other layer on the tracking control. A sub push-pull signal correcting section corrects a sub push-pull signal to be generated from returning light of a sub beam in such a manner that a track crossing component of a main push-pull signal to be generated from returning light of a main beam, and a track crossing component of the sub push-pull signal to be generated from the returning light of the sub beam are canceled. A low pass filter reduces a high frequency component of the sub push-pull signal corrected by the sub push-pull signal correcting section. A subtractor subtracts a sub push-pull signal passing the low pass filter from the main push-pull signal to thereby generate a tracking error signal.

Abstract: A two-split seal block is enabled, when closed, to come into close contact with an abutment surface of the seal block and an outer circumferential surface of an extrusion stem or fix dummy block via a seal member pasted to the abutment surface of the seal block and a seal member provided on an inner circumferential surface of the seal block and a pressing means capable of pressing and causing a seal member provided on a container side end surface of the seal block against and to come into close contact with a stem side end surface of the container is provided movably in the extrusion direction, and the seal block is provided so as to be capable of opening and closing by rocking in a direction crossing the axial direction of the extrusion stem and at the same time, the seal block is provided so as to be capable of moving in the direction crossing the axial direction of the extrusion stem in an open state.

Abstract: The output voltage of a cathode drive-type semiconductor laser driving circuit is set to a minimum, power consumption by a driving circuit portion is suppressed, and the heat that is generated by the optical head or the optical disc device is reduced. In addition to a conventional configuration, the semiconductor laser driving circuit of the invention measures the cathode voltage (Vout) of a semiconductor laser (1) and controls the anode voltage (Vld) such that the cathode voltage (Vout) becomes a predetermined level, and by doing so sets the output voltage of the semiconductor laser driving circuit to a predetermined level in order to curtail power consumption by the driving circuit and minimize the rise in temperature of the optical head or the optical disc device.

Abstract: An optical disc apparatus has: a spherical aberration correction unit (7) which corrects the spherical aberration generated in a light spot on a recording layer; a control unit (52) which focuses a light beam on a predetermined recording layer, and shifts the focal point position of the light beam from the current recording layer to another recording layer; and a focus jump control unit (60) which controls correction of spherical aberration and shift of the focal point position based on the interlayer distance between the current recording layer and a recording layer which adjoins in a direction opposite to a direction of shifting the focal point position of the light beam. By this configuration, focus jump is stably executed.

Abstract: 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 recording apparatus (10) is provided with a tracking servo (13) for tracking a spiral track of concave and convex marks, an analog signal processor (14) for extracting a reproduction signal corresponding to the concave and convex marks, a digital signal processor (15) for extracting a channel clock synchronized with a channel bit length of the concave and convex marks, and a sub-information recording section (30) for recording sub-information by irradiating laser light based on the tracking to the spiral track. The sub-information recording section (30) records all the sub-information by repeating a process of recording a part of the sub-information by discretely irradiating laser light at a specified interval and with a specified frequency in synchronism with a channel clock by one tracking to form recordable marks on a reflective film a plurality of times.

Abstract: The invention provides a tracking control device, a tracking control method, and an optical disc apparatus that enable to stably perform the tracking control, and reduce an influence of stray light from the other layer on the tracking control. A sub push-pull signal correcting section corrects a sub push-pull signal to be generated from returning light of a sub beam in such a manner that a track crossing component of a main push-pull signal to be generated from returning light of a main beam, and a track crossing component of the sub push-pull signal to be generated from the returning light of the sub beam are canceled. A low pass filter reduces a high frequency component of the sub push-pull signal corrected by the sub push-pull signal correcting section. A subtractor subtracts a sub push-pull signal passing the low pass filter from the main push-pull signal to thereby generate a tracking error signal.

Abstract: An object of this invention is to improve stability of tracking control and improve recording and reproduction performance. The tracking control device comprises a main push-pull signal generation section, which generates a main push-pull signal based on a signal obtained by photoelectric conversion of return light of the main beam; a microcomputer, which detects an other-layer stray light signal component included in a signal obtained by photoelectric conversion of return light of the sub-beam; a signal correction section, which corrects the signal obtained by photoelectric conversion of the return light of the sub-beam, based on the other-layer stray light signal component; and a sub-push-pull signal generation section, which generates a sub-push-pull signal based on the corrected signal obtained by photoelectric conversion of the return light of the sub-beam.

Abstract: A fixing device is configured by: a pushing device of the die unit capable of pushing the die unit from ahead in the direction of extrusion; and a pressing device of the die unit capable of pressing a die ring and the die cassette from above in a direction intersecting the direction of extrusion. The fixing device of the die unit is arranged between the discard cutting device and an end platen and at the same time, the pressing device of the die unit is provided with a fixing metal fitting of the pushing device of the die unit and a pressing metal fitting of the die ring and when the pressing device of the die unit operates and presses and fixes the die ring and the die cassette, the pushing device of the die is fixed.

Abstract: To adjust the symmetry of a focus error signal, the symmetry of the focus error signal needs to be measured during upward and downward driving of an objective lens, which is performed at every varying setting of a signal correction gain value of the focus error signal, and such adjustment takes a long time. An optical disc device (100) measures a focus error signal before differentiation at a local maximum point and a local minimum point of a focus error signal using a prior-to-differentiation FE measurement unit (50), and calculates the symmetry of the S-shape of a focus error signal using a symmetry calculation unit (51), and performs balance adjustment based on the calculation result. The device with this structure adjusts the symmetry of a focus error signal at a high speed by requiring an upward and downward operation to be performed only once.