Kabushiki Kaisha Toshiba

Ryoji Takeuchi

Akihiko Doi

Tomohisa Yoshimaru

An optical apparatus for an optical disk recording/reproducing apparatus including a recording laser light emitting device emitting a recording beam for recording data on an optical disk, a reproduction laser light emitting device provided near the recording laser light emitting device and emitting a reproducing beam for reproducing data and a reproduction photo-detector receiving and detecting reflection light of the reproducing beam. By providing light emitting devices dedicated to the recording beam and the reproducing beam, respectively, it is possible to reproduce data while recording the data.

Optical apparatus used for optical disk recording and reproducing apparatus

An optical disk apparatus comprising a head having an objective lens, a tracking controller, a CPU, and a counter. The CPU determines a tracking error if the count of the counter is greater than a predetermined value when the disk is rotated 360.degree. after the counter has been cleared during data-reproducing operation. Then, the CPU outputs a tracking re-try signal to the tracking controller. In response to this signal, the controller locks the lens at the center position within the head. Then, the frequency of vibration of the lens decreases so much that servo tracking is no longer required. When the relative rate-of-change of tracking position between the head and the disk has decreased sufficiently, the CPU determines that the head is applying a laser beam onto the target track of the disk. Thus, every time a tracking error is made due to an external force, the servo tracking is automatically performed, and the apparatus is therefore reliable. The CPU also outputs a tracking re-try signal if the head is stopped upon completion of coarse accessing of an optical disk. In this case, the lens is locked at the center position. Therefore, the vibration of the lens can be suppressed within a short time after the completion of the coarse accessing. As soon as the relative rate-of-change of tracking position between the lens and the disk decreases sufficiently, the head starts applying a laser beam onto the target track of the disk, thus tracking the optical disk.

Optical disk apparatus

In an information recording system, a semiconductor laser is energized in response to a drive current which is modulated in accordance with a recording signal in a recording mode so that a modulated laser beam is generated from the semiconductor laser. The modulated laser beam is focused on an optical disk and is reflected from the optical disk and the reflected laser beam is detected by an photo-detector. A detection signal from the detector is compared with a predetermined threshold level by a binary circuit and a relationship between the recording signal and an output signal from the binary circuit is detected by a detection circuit. In a overwrite mode in which the laser beam is focused on a pit or pits on the optical disk, an overwrite detection signal is generated from the detection circuit and the overwrite detection signal is counted by a counter circuit. When the counter circuit counts a predetermined count value, the counter circuit generates a recording inhibition signal for preventing the semiconductor laser from generating the modulated laser beam.

System for recording information on an optical recording medium

In an information recording system, a semiconductor laser is energized in response to a drive current which is modulated in accordance with a recording signal in a recording mode so that a modulated laser beam is generated from the semiconductor laser. The modulated laser beam is focused on an optical disk and is reflected from the optical disk and the reflected laser beam is detected by an photo-detector. A detection signal from the detector is compared with a predetermined threshold level which is set in accordance with the peak intensity by a binary circuit and a relationship between the recording signal and an output signal from the binary circuit is detected by a detection circuit. In an overwrite mode in which the laser beam is focused on pit or pits on the optical disk, an overwrite detection signal is generated from the detection circuit and the overwrite detection signal is mounted by a counter circuit. When the counter circuit counts a predetermined count value, the counter citcuit generates a recording inhibition signal for preventing the semiconductor laser from generating the modulated laser beam.

Information recording system capable of preventing overwriting

An apparatus for reproducing data from an optical disk by a light beam includes a housing which is movable in the readial direction of the optical disk. The housing includes a directing element for directing the light beam onto the optical disk, a detector for detecting the light beam from the optical disk so as to generate an electrical signal corresponding to the detected light beam, a dividing element for dividing the electrical signal generated by the detector into a low frequency component and a high frequency component, and an amplifier for amplifying the high frequency component divided by the dividing element. The reproducing apparatus further includes a moving element for moving the housing in radial direction of the optical disk, an adjuster for adjusting a distance of the directing element with respect to the optical disk in response to the low frequency component divided by the dividing element, and a reproducing circuit for reproducing data from the optical disk in response to the amplifier.

Apparatus having a movable portion and a fixed portion for reproducing

A power amplifying apparatus for amplifying an input signal to drive a load, includes an amplifier for amplifying the input signal so as to generate an output signal for driving the load and a current/voltage converter for current/voltage converting the output signal generated by the amplifier and feeding back the converted voltage to the amplifier. The converted voltage is used to control the amplitude of the output signal which flows into the load. The power amplifying apparatus further includes a circuit for determining a current-to-voltage conversion ratio of the current/voltage converter. The amplitude of the converted voltage converted by the current/voltage converter may be varied in accordance with the current-to-voltage converting ratio determined by the determining circuit.

Power amplifying apparatus for optical disk apparatus

An apparatus for adjusting the amount of laser light includes a laser light generator for generating laser light, and a detector for detecting the amount of the laser light so as to generate an output signal corresponding to the amount of the laser light. The apparatus further includes a first adjuster for adjusting the amplitude of the output signal and a second adjuster for adjusting the amount of the laser light generated by the laser light generator. The adjustment of the amplitude of the output signal and the adjustment of the amount of the laser light are performed separately through a selector.

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Yokohama, Japan

Ryoji Takeuchi