Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Toshiba Samsung Storage Technology Corporation

Hiroshi Nakane

Takeshi Nakano

Daiki Nabeshima

Satoru Maeda

Taiji Inomata

Yasuhiro Hayashi

Takuro Ono

Mikio Kakizaki

Noboru Aoyama

Shigeru Todokoro

Kazumi Sugiyama

Tatsuro Shimizu

Takayuki Uchida

Shigeo Tsuchiya

An optical disk device includes a pickup head, and a controller which controls the pickup head. The controller subtracting a second measured value determined from an amplitude value of the tracking error signal when the pickup head irradiates a second area of the optical disk with a first DVD laser beam, from a first measured value determined from the amplitude value of the tracking error signal output when the pickup irradiates a first area of the optical disk with the first DVD laser beam, to determine an evaluation value. The controller determining that the optical disk is the first DVD if the evaluation value is smaller than a reference value, and determining that the installed optical disk is a second DVD if the evaluation value is larger than the reference value, the second DVD optical disk having a smaller track width than the first DVD optical disk.

Optical disk device and method for determining disk type

An optical disk apparatus includes an optical pickup head (PUH) which outputs a laser beam through an objective lens. When a control unit receives an instruction to halt data read-out from an optical disk, the control unit moves the PUH to a predetermined position, stores a focus driving voltage corresponding to a position of the objective lens in a memory unit, and halts the output of the laser beam from the PUH. When the control unit receives an instruction to resume the data read-out, the control unit resumes the output of the laser beam from the PUH, starts a focus search on the basis of the focus driving voltage that is stored in the memory unit, moves the objective lens in a direction toward the optical disk, and achieves focus adjustment.

Optical disk apparatus and data read-out control method

A rotation correcting apparatus has a tracking servo controller which generates a tracking signal to perform a tracking servo control for guiding an optical beam spot outputted from a pickup to tracks of an optical disk and a track jump control for moving the optical beam spot to a certain track; a feed motor controller which controls a feed motor for moving the pickup to radius direction of the optical disk; a storage which stores signal component with a prescribed frequency band including a rotation frequency of the optical disk, the signal component being included in an output signal of the tracking servo controller; and a combination unit which combines the signal component stored in the storage with the tracking signal to generate an ultimate tracking signal for the tracking servo control and the tracking jump control, wherein the feed motor controller controls the feed motor based on the tracking signal generated by the tracking servo controller without using the signal component stored in the storage.

Rotation correcting apparatus and optical disk apparatus

Comparators compare the amplitudes of a DPD tracking error signal indicating the phase difference between the detection signals supplied from a photodetector, and a PP tracking error signal indicating the level difference between the detection signals with the reference values, respectively. A gain control amplifier mutes a tracking error signal with the maximum amplitude smaller than a reference value.

Disk apparatus and method of generating a tracking error signal

A Differential Phase Detecting (DPD) tracking error generating section generates a DPD tracking error signal from a plurality of sense signals supplied from an optical sensor. A Push Pull (PP) tracking error generating section generates a PP tracking error signal from a plurality of sense signals supplied from the optical sensor. The amplitude of each of the DPD tracking error signal and PP tracking error signal is adjusted suitably under the control of a CPU. The suitably adjusted signals are added by an adder, thereby generating a tracking error signal.

Optical disk apparatus

An optical disk has a reflecting layer and a transparent substrate formed on the reflecting layer. The type of the optical disk changes depending on the physical characteristics of the reflecting layer and the thickness of the transparent substrate. When discriminating such a disk, an objective lens which focuses an optical beam on the disk is moved toward the disk. Along with this movement, a detection signal that detects an optical beam reflected by the disk generates a detection signal. First, a peak accompanying mirror surface reflection of the surface of the disk appears, and then a peak accompanying reflection of the reflecting layer appears. The type of the disk which concerns the transparent substrate of the optical disk is discriminated from the time interval between the two peaks. The characteristics and reflection level of the RF component of detection signal generated by the detector change in accordance with the count of reflecting layers and the reflectance of the reflecting layer(s). This discriminates the physical characteristics of the reflecting surface and the type of the optical disk. In this manner, with the disk type discrimination method and device according to the present invention, discrimination can be performed within a substantially constant, short period of time after the disk is set in the device until the disk is recognized.

Disk discrimination method and device

Disc reading apparatus having a transferable motor unit and motor power

A track jump control circuit includes: a head; a rotary motor which drives the head and is controlled in accordance with an input signal; a unit for detecting a speed of rotation corresponding to the rotation of the rotary motor; distance detection unit for producing a signal corresponding to a distance which the head should move with using no data read by the head when the head is moved to a desired position; speed setting unit for setting a speed of movement of the head based on the signal produced by the distance detection unit; and a unit for comparing a speed detected by the speed detection unit with a speed set by the speed setting unit to produce an output as the input signal to the rotary motor.

Speed detection apparatus, speed control motor, and track jump control

A track jump control circuit includes a head; a rotary motor which drives the head and is controlled in accordance with an input signal; a unit for detecting a speed of rotation corresponding to the rotation of the rotary motor; distance detection unit for producing a signal corresponding to a distance which the head should move with using no data read by the head when the head is moved to a desired position; speed setting unit for setting a speed of movement of the head based on the signal produced by the distance detection unit; and a unit for comparing a speed detected by the speed detection unit with a speed set by the speed setting unit to produce an output as the input signal to the rotary motor.

A disc reproducing system having a pickup for reading data recorded on a disc that is rotated by a disc drive motor. The system, also has a clock signal generator for generating a clock signal that is phase-locked with the data read by a pickup, and a processor for processing the data read by the pickup based on the clock signal generated by the clock signal generating means. Further included in the system is a linear velocity signal generator for generating a linear velocity signal with a frequency that is related to the rotational speed of the disc, a servo controller for controlling the rotation speed of the disc drive motor so as to keep constant a relative speed between the pickup and the disc, and a pickup feed motor for moving the pickup in the radial direction of the disc. The apparatus is characterized by the fact that a capture range of the clock signal generator can be controlled to meet the clock signal with the data read by the pickup at a completion of the pickup feed operation.

Track jump servo apparatus for disc reproducing system

A drive speed detector for a pickup feed motor including a detector for detecting the drive speed of the optical pickup feed motor by generating an AC signal with a frequency which is proportional to the drive speed of the optical pickup feed motor and a controller for controlling the sensitivity of the detecting means in order to uniform an amplitude level of the AC signal output from the detecting means.

Drive speed detector for a motor that drives a data reproducing device

In a disk reproducing device of this invention for reading out data from a disk by means of a pickup element, a speed signal proportional to the speed of relative movement between the disk and the pickup element is created in a case where the pickup element is moved in the radial direction of the disk according to a high frequency signal (RF) read out from the disk and a tracking error signal (TE) derived from the high frequency signal (RF).

Device for detecting traveling speed of pickup

A track jump control circuit comprises: a head; a rotary motor which drives the head and is controlled in accordance with an input signal; a unit for detecting a speed of rotation corresponding to the rotation of the rotary motor; distance detection unit for producing a signal corresponding to a distance which the head should move with using no data read by the head when the head is moved to a desired position; speed setting unit for setting a speed of movement of the head based on the signal produced by the distance detection unit; and a unit for comparing a speed detected by the speed detection unit with a speed set by the speed setting unit to produce an output as the input signal to the rotary motor.

An optical data reading apparatus for reading data stored in an optical record disc includes an optical pickup head for transducing an optical signal from the optical record disc to an electrical signal, a detector for detecting the level of the electrical signal, a source for supplying a reference signal representative of a minimum acceptable level for the electrical signal, a comparator for continuously comparing the level of the electrical signal and the reference signal and outputting a comparison signal when the level of the electrical signal is less than the reference signal and a warning device responsive to the comparison signal to indicate that the level of the electrical signal is below the minimum acceptable level.

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Fukaya, Japan

Hiroshi Nakane