Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Canon Kabushiki Kaisha

Kenzo Ishibashi

Shunji O'Hara

Takashi Ishida

Tadashige Furutani

Yasumori Hino

Motoshi Ito

Shunji Ohara

Masahiro Birukawa

Makoto Ichinose

Hisashi Senga

Katsumi Gotoh

Takatoshi Yukimasa

Toshio Satoh

Yoshihisa Fukushima

Shinichi Tanaka

Takashi Inoue

Kenji Koishi

Yuji Takagi

Mitsuro Moriya

Hideshi Ishihara

Takeharu Yamamoto

Hideki Hayashi

Takahiro Nagai

Hiroshi Sugimoto

Eiji Ueda

Yasuyuki Miyaoka

Keiji Nishikiori

Hirotake Ando

Tomotada Kamei

Akira Yoshikawa

Chikashi Inokuchi

Shinji Kubota

Keiichi Kawashima

Yohichi Saitoh

Hirofumi Ide

Mayumi Hironaka

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 () 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.

Semiconductor laser driving circuit, and optical disc device and integrated circuit provided with semiconductor laser driving circuit

An optical pickup according to the present invention includes an integrated circuit element (LDD)for driving first, second, and third semiconductor lasers, and. The LDDis shaped so as to have a rectangular principal face surrounded by one side, with a plurality of input/output pins being arranged along each side. The plurality of input/output pins include a first pin group connected to a blue-violet laserwhose oscillation wavelength is the shortest, a second pin group connected to a red laser, and a third pin group connected to an infrared laser. The wiring structure of the optical pickup includes a first transmission linefor connecting the first pin group to the blue-violet laser, a second transmission linefor connecting the second pin group to the red laser, and a third transmission linefor connecting the third pin group to the infrared laser, where the first transmission lineis shorter than both the second and third transmission linesand. Of the rectangular principal face of the LDD, the side along which the first pin group is provided is orthogonal to the side along which the second pin group is provided or to the side along which the third pin group is provided.

Optical pickup and optical disc device

A tracking control apparatus for stable tracking lead-in of an optical disc which has wobble grooves as tracks, including: a signal detection unit that detects tracking error and wobble signals from an optical spot; a speed detection unit that calculates a relative moving speed between the optical spot and the tracks; a polarity judgment unit that judges that the optical spot is on a land if a wobble signal amplitude value is equal to or lower than a predetermined value in the vicinity of a zero-cross point; a moving direction judgment unit that, when the relative moving speed is within a predetermined range and the optical spot is on a land, judges a moving direction of the optical spot from a rise/decay direction of the tracking error signal; and a control unit that performs a tracking lead-in by reducing the moving speed, based on the moving speed and moving direction.

Optical disc tracking control device, tracking control method, and tracking control program

A semiconductor laser device according to the present invention includes a mechanism section having a semiconductor laser, a first frame for holding the mechanism section and radiating heat generated in the mechanism section, a control section for controlling the mechanism section, a second frame for holding the control section and radiating heat generated in the control section, and a coupling section for insulatively coupling the first frame to the second frame.

Semiconductor laser device

An optical disk according to the present invention is the optical disk on which secret information on unique information given to a specific optical disk manufacturer or a specific optical disk and information recorded on an infringement disk list of identifying an illegitimate optical disk manufacturer or an illegitimate optical disk are recorded in advance, and the optical disk has an area in which reproduction-only encrypted data encrypted based on the secret information and the information on the infringement disk list is recorded in advance or an area capable of recording the encrypted data to be encrypted based on the secret information and the information on the infringement disk list.

Optical disk and optical method

An optical disc apparatus is provided, which comprising a laser light emitting portion for generating laser light for irradiating an optical disc, and a laser control portion for controlling a light emission operation of the laser light emitting portion. The laser control portion causes the laser light emitting portion to emit light with a first period during a first operation, and the laser control portion causes the laser light emitting portion to emit light with a second period during a second operation. The first period and the second period are different from each other.

Optical disc apparatus, camera apparatus, and method for controlling light emission operation

An optical disc cutting apparatus capable of suppressing an unnecessary deflection component and unnecessary light intensity variation component and manufacturing a optical disc suitable for a high definition, high precision and high density optical disc. The optical disc cutting apparatus includes a light beam controller including at least one of an optical modulator for controlling the light intensity of light beam emitted from a laser beam source and an optical deflector for controlling the deflection amount of the light beam in the radial direction on an optical disc original master, a deflection error detector for detecting a deflection error in the radial direction included in the light beams controlled by the light beam controller, a second optical deflector, which is disposed between the light beam controller and the deflection error detector, for deflecting the light beams in the radial direction, and a feedback controller for feeding back a feedback signal using the deflection error in the radial direction to the second optical deflector.

Optical disc cutting apparatus and method for manufacturing optical disc

An optical disk is made of tracks that are magnetically separated from one another by scanning a focused light beam over lands between tracks at a predetermined power and annealing to lower the magnetic anisotropy of a magnetic layer on the lands, and is provided with a power testing region comprising one or more tracks for finding the predetermined annealing power at the location of at least one of the group consisting of a specific region within the data region, a region more to the inner side than the innermost track of the data region, and a region more to the outer side than the outermost track of the data region. Thus, an optical disk and a manufacturing method for the same can be provided that have a high recording density and with which annealing can be implemented in a short time and at the correct annealing width.

Optical disk and manufacturing method for the same

A control adjustment method for adjusting a control of a recording/reproduction apparatus for a disc-shaped recording medium is provided, wherein the control is adjusted in response to an environmental change inside the recording/reproduction apparatus, such as a temperature change, the control adjustment method comprising the steps of: requesting an execution of the control adjustment; determining whether to inhibit or approve the execution of the control adjustment; and executing the control adjustment in the case where the execution of the control adjustment is approved in the step of determining the execution of adjustment.

Method for adjusting control operation in an optical disc recording device

A a recording method and apparatus for an optical disk employs a data format having a fixed pattern sync portion in which a minimum run length of zeros and the maximum run length of zeros are not adjacent to each other. As such temperature difference caused during recording the optical disk may be made smaller, thermal stress applied upon the medium may be reduced, the deterioration thereof may be restrained, and the repetitive frequency of the medium may be improved.

Recording method and recording and reproducing apparatus for optical disk

A recording method and apparatus for an optical disk employs a data format having a fixed pattern sync portion in which a minimum run length of zeros and a maximum run length of zeros are not adjacent to each other. As such temperature difference caused during recording the optical disk may be made smaller thermal stress applied upon the medium may be reduced, the deterioration thereof may be restrained, and the repetitive frequency of the medium may be improved.

A recording method and apparatus for an optical disk employs a data format having a fixed pattern sync portion in which a minimum run length of zeros and a maximum run length of zeros are not adjacent to each other. As such, temperature difference caused during recording the optical disk may be made smaller, thermal stress applied upon the medium may be reduced, the deterioration thereof may be restrained, and the repetitive frequency of the medium may be improved.

In an optical recording and reproducing apparatus which forms at least first and second light spots on a track of an optical recording medium to record, reproduce or erase information, a movable range of the second light spot is limited to less than one half of a track pitch, normal to the track, from the track to prevent tracks other than a target track from being miserased, misrecorded or misreproduced. When a deviation of the second light spot from the target track exceeds a predetermined amount, light emission of the second light spot is stopped to prevent a track other than the target track from being miserased, misrecorded or misreproduced. When the deviation of the second light spot from the target track exceeds the predetermined amount, the second light spot is returned to a neutral position to prevent a track other than the target track from being miserased, misrecorded or misreproduced.

Optical recording and reproducing apparatus having a plurality of light

A recording method and apparatus for an optical disk employs a data format having a fixed pattern sync portion in which a minimum run length of zeros and a maximum run length of zeros are not adjacent to each other. As such, temperature difference caused during recording the optical disk may be made smaller thermal stress applied upon the medium may be reduced, the deterioration thereof may be restrained, and the repetitive frequency of the medium may be improved.

Recording method and recording apparatus for optical disk

A clock changeover apparatus including a reference frequency divider for dividing a reference clock by a first frequency division number; a comparative frequency divider for dividing by a second frequency division number an output clock obtained by the clock changeover apparatus; a phase comparator for comparing phase of a signal of the reference frequency divider with that of the comparative frequency divider; a clock controller for changing the output clock so as to make the phase of the signal of the reference frequency divider coincident with that of the comparative frequency divider; a clock determining member which gives an initial value of the output clock to the clock controller and is capable of selecting the initial value of the output clock arbitrarily; a changeover member for effecting changeover between the first and second frequency division numbers; and a phase lock detector for monitoring whether or not the phase of the signal of the reference frequency divider coincides with that of the comparative frequency divider.

Growing community of inventors

Moriguchi, Japan

Kenzo Ishibashi