Abstract: A battery device designed so that a plurality of battery modules (1) are arranged in rows at given spaces in a enclosure (2). Turbulence accelerators (5), such as dummy battery units or the like, are provided in a position on the uppermost-stream side of the enclosure in which air flows in the direction of arrangement of the battery modules. The heat transfer ability for the battery modules in the upper-stream position is enhanced by the turbulence accelerators which disorders the airflow introduced into the enclosure. Auxiliary coolant intake ports (7) for the introduction of a coolant are provided in the middle of an airflow path, whereby the heat transfer ability on the lower-stream side is enhanced, so that battery temperature differences between the battery units arranged in the enclosure can be restrained. Thus, a simple-construction battery device is realized enjoying improved quality and operation stability.

Abstract: An initializing apparatus includes a laser light source for emitting an erasing laser light for initializing an optical disk, a laser drive circuit for driving the laser light source according to an AC waveform signal, an optical system for irradiating the optical disk with the erasing laser light and track address detecting circuitry for detecting the track address. Furthermore, the laser light source, the laser drive circuit and the optical system are previously adjusted so that an amorphous portion having a size of ½ or less of a wavelength of the erasing laser light may be formed at the inside of a melting re-crystallization portion.

Abstract: An optical disk apparatus of the present invention forms, in a first embodiment, two laser beams for erasure of data and irradiates the two laser beams from a single erasing head 102 so that focuses 207 and 208 thereof may be disposed on a same track of an optical disk 206. In order to construct the erasure head so as to provide two beams, either a two beam semiconductor laser 201 may be used or a beam from a semiconductor laser 215 may be divided into two beams. For the means for dividing the beam into two beams, a Wollaston polarizing prism 216, a Bragg diffraction grating 218, a Foucault prism 219 or some other suitable element can be used. Meanwhile, in a second embodiment, data are reproduced by an optical equivalence method using an optical disk 82, 100 or 206 of a phase change medium which exhibits a phase difference smaller than 180 degrees in reflected light therefrom based on recorded data. The phase difference preferably ranges from 120 degrees to 150 degrees.

Abstract: According to an astigmatic difference correcting method for an optical head, a rotational optical member which is arranged between a first laser beam source having an astigmatic difference and a collimator lens to be rotatable around an optical path of a laser beam of a first wavelength emitted from the first laser beam source is rotated and adjusted. Rotation and adjustment of the rotational optical member is caused to set a minimum difference between focal positions in an X-axis direction and in a Y-axis direction which are perpendicular to the optical path of the laser beam. The laser beam in which the difference between the focusing offset positions is minimum is irradiated on an optical disk having a recording density having a bit length not more than half a laser wavelength.

Abstract: According to an astigmatic difference correcting method for an optical head, a rotational optical member which is arranged between a first laser beam source having an astigmatic difference and a collimator lens to be rotatable around an optical path of a laser beam of a first wavelength emitted from the first laser beam source is rotated and adjusted. Rotation and adjustment of the rotational optical member is caused to set a minimum difference between focal positions in an X-axis direction and in a Y-axis direction which are perpendicular to the optical path of the laser beam. The laser beam in which the difference between the focusing offset positions is minimum is irradiated on an optical disk having a recording density having a bit length not more than half a laser wavelength.

Abstract: An optical recording medium is provided, this medium having a first substrate, onto the surface of which is formed a phase-change recording layer, and a second substrate, onto the surface of which is formed a magneto-optical recording layer, these layers being adhered to one another in a manner that causes their surface to be mutually opposing. By providing a means for selectively collecting laser light onto the phase-change recording layer and onto the magneto-optical recording layer, and selecting the output of either a differential amplifier or amplifier, to which are input the received-light outputs from light reflected from the optical recording medium, it is possible to perform access of both the phase-change recording layer and the magneto-optical recording layer, and to perform both recording and playbacking of information at high speed.

Abstract: The invention relates to a technique to detect lands and grooves formed on an optical disk, and is intended to provide a land/groove detecting apparatus capable of steadily obtaining track detection signals and land/groove detection signals. According to the invention, +1-, 0- and -1-order light beams obtained from a three-beam type optical head are received by a 6-divided optical sensor, and the 0-order beam is detected by optical sensor elements a, b, c and d of a 4-divided optical sensor while the +1- and -1-order beams are detected by two optical sensor elements e and f, respectively, on the two sides of the 4-divided optical sensor. The output signals of the optical sensor elements a, b, c, d, e and f are denoted by A, B, C, D, E and F, respectively. As a tracking error signal and a land/groove detection signal are calculated by equations TE=E-F and LG=(2.times.

Abstract: An optical disc apparatus which records and reproduces an information signal from an optical disc having land and groove tracks, whose width ratio being set to be 1 or to be a value close thereto, is capable of detecting a moving direction of a beam spot in a random access mode, by applying a four-division or six-division optical sensor, segmented by division lines tilted by 45.degree..+-.25.degree. from the track tangential direction, wherein two output signals having a phase difference of about 90.degree. are produced and the moving direction is detected.

Abstract: An optical head apparatus is realized in which an objective lens actuator and the whole optical system are reduced in height, and which can be used in common between a system in which the light beam comes incident in the direction of the radius of the information disk and another in which the light beam is arranged in a direction tangent to the information disk. A lens holder having a substantially hexagonally shaped plane is supported by two wire springs, each shaped in a triangle with two of its aides extended and fitted to an actuator base, to be able to freely move up and down and to freely rotate. On two side walls of a lens holder are arranged tracking coils and focusing coils, and magnets are arranged in opposite positions of the actuator base.

Abstract: A device capable of initializing an optical disc in high-speed and accurate manner includes a moving table (106) movable in the radius direction of a optical disc (101) to which first and second photo head moving sections (107) and (108) are fixed. A laser beam (131) emitted from a fixed section (105) is branched into two erasing beams through a beam splitter (136) and a reflection mirror (138), and the erasing beams are irradiated on the optical disc (101) from respective objective lenses (142) and (152). The erasing beam are of sizes that can erase a plurality of tracks simultaneously. The moving table (106) advances by a plurality of tracks to thereby initialize the plurality of tracks at once.

Abstract: A 0-th order diffracted beam and a plus order diffracted beam generated by passing a single beam emitted from a semiconductor laser through a diffraction grating are focused on a recorded mark on an optical track. Signals of reflected light of the two beams from the recorded mark are detected by a two-element sensor. A difference between the signals is calculated by a differential amplifier. The difference signal is differentiated by a differentiator and the differentiated signal input into a zero cross detector which detects a zero cross point of the differentiated signal. Information represented by the recorded mark is played back according to the zero cross point detected by the zero cross detector.

Abstract: A beam emitted from a beam source is irradiated on an optical disc. A part of the reflected beam from the optical disc is incident on a four-piece prism, while the remaining part of the reflected beam is incident on a second sensor. The reflected beam incident on the four-piece prism is split into four beams outgoing in different directions so that they are incident on the first optical sensor. The first optical sensor is provided with first and second optical sensor elements, and the first optical sensor element that has received two beams of four beams split by the four-piece prism outputs a signal for producing a focus error signal. A plurality of operational amplifiers generate a focus error signal based on the signal output from the first optical sensor element. On the other hand, the second optical sensor element that has received two beams of a plurality of beams divided by the prism outputs a signal for generating an RF signal.

Abstract: An optical disk initializing apparatus includes the first optical system having a gain waveguide laser, a collimator lens, diffraction gratings, and a 45.degree. mirror, the second optical system having a 680-nm red laser, a polarizing beam splitter, a collimator lens, and a .lambda./4 plate, a dichroic mirror, an objective lens, an optical sensor, a phase compensator, a voltage-current conversion amplifier, and an objective lens actuator. The first optical system outputs a first beam for initialization. The second optical system outputs a second beam having a wavelength different from that of the first beam. The dichroic mirror multiplexes the beam emerging from the first optical system and the second beam emerging from the second optical system. The objective lens focuses an output beam emerging from the dichroic mirror on a phase change recording or magneto-optical recording optical disk. The optical sensor detects a focusing error signal from a return beam of the second beam reflected by the optical disk.

Abstract: According to an astigmatic difference correcting method for an optical head, a rotational optical member which is arranged between a first laser beam source having an astigmatic difference and a collimator lens to be rotatable around an optical path of a laser beam of a first wavelength emitted from the first laser beam source is rotated and adjusted. Rotation and adjustment, of the rotational optical member is caused to set a minimum difference between focal positions in an X-axis direction and in a Y-axis direction which are perpendicular to the optical path of the laser beam. The laser beam in which the difference between the focusing offset positions is minimum is irradiated on an optical disk having a recording density having a bit length not more than half a laser wavelength.

Abstract: A matrix circuit receives, as inputs, signals after opto-electrical conversion of reflected light of three light beams of the plus first, 0-th and minus first order light beams from the optical disk. Based on the signals, four tracking error signal are produced by the matrix circuit. Zero cross calculator detects zero cross points of the four tracking error signals, whereby movement of the beam spot formed of the light beams is monitored with points at 1/4, 2/4, 3/4 and 4/4 of a track pitch. Here, recording or reproduction is performed on both lands and grooves. The mute state of a tracking servo is released at a timing when the beam spot passes through a point at 2/4 of the track pitch and the polarity of the tracking servo is changed over at this timing.

Abstract: An optical head apparatus for a phase change disk includes a semiconductor laser, a rectangular prism, diffraction gratings, an optical sensor element, and a four-divisional optical sensor. The semiconductor laser outputs a laser beam. The rectangular prism has an inclined surface formed with a polarizing beam splitter film, and deflects the laser beam emitted from the semiconductor laser by 90.degree. toward an optical disk. The polarizing beam splitter passes a return beam of the laser beam which is reflected by the optical disk. The diffraction gratings are arranged in contact with or close to the inclined surface of the prism, and generate a 0th-order polarized laser beam and .+-.1st-order polarized laser beams from the beam returning from the optical disk through the rectangular prism. The optical sensor element detects the 0th-order polarized laser beam output from the diffraction gratings. A reproducing signal is obtained from an output from the optical sensor element.

Abstract: An objective lens actuator for an optical head includes an objective lens, an objective lens holder, a focusing coil, a pair of tracking coils, a plurality of wire springs, a magnetic circuit, and a pair of photosensors. The objective lens is constituted by an aspherical plastic lens to receive a beam reflected by an optical disk. The objective lens holder has a substantially square frame shape to hold the objective lens. The focusing coil is wound on the objective lens holder. The pair of tracking coils are arranged on parallel side surfaces of the objective lens holder, respectively. The plurality of wire springs hold the objective lens holder with a degree of freedom in focusing and tracking directions. The magnetic circuit has a substantially closed magnetic circuit arrangement to cooperate with the focusing and tracking coils to electromagnetically drive the objective lens holder.

Abstract: It is the object of the invention to decrease the gain peak of an objective lens holder at a natural frequency of a biaxial objective lens actuator used in an optical disc system using a reproducing-only-disc, a write-once-disc or an erasable disc. The out-line of a construction is such that each support for the objective lens holder is composed of plural elastic wires surrounded by damping material (silicone, for example), and a damping effect can be achieved by shearing stress caused in the damping material, and each of the support springs passes through a hole of a damping box, wherein the clearance between the support spring and the inner wall of the hole of the damping box is filled with gelled damping material. A further improvement of damping can be achieved by the damping box.

Abstract: An objective lens actuator for an optical head includes an objective lens, an objective lens holder, a focusing coil, a pair of tracking coils, a plurality of wire springs, a magnetic circuit, and a pair of photosensors. The objective lens is constituted by an aspherical plastic lens to receive a beam reflected by an optical disk. The objective lens holder has a substantially square frame shape to hold the objective lens. The focusing coil is wound on the objective lens holder. The pair of tracking coils are arranged on parallel side surfaces of the objective lens holder, respectively. The plurality of wire springs hold the objective lens holder with a degree of freedom in focusing and tracking directions. The magnetic circuit has a substantially closed magnetic circuit arrangement to cooperate with the focusing and tracking coils to electromagnetically drive the objective lens holder.

Abstract: An optical head has the structure that an optical system is mounted on a movable body and is separated from a fixed optical system with which the optical system cooperates and an objective lens actuator does not have the magnetic circuit on the movable body. The objective lens actuator is balanced so that the focusing drive point of the objective lens actuator corresponds to the gravity center thereof.