Sanyo Electric Co., Ltd.

Noboru Mamiya

Kenji Nakao

Satoshi Sumi

Ken Hirose

Toshiaki Hioki

Kenji Torazawa

Kenji Asano

Yoshiharu Uchihara

Yoshihiro Hori

Hisashi Matsuyama

Yoshihisa Suzuki

Seiichiro Takahashi

Akiomi Kunisa

Nobuo Itoh

Hiroshi Watanabe

Kenji Nagatomi

Kenji Tanase

Morio Nakatani

Katsutoshi Hibino

Toshihide Hamaguchi

Masahiro Nakata

Sayoko Tanaka

Shigeki Hori

Hideharu Toda

Koichi Kawakami

Tomohiro Goto

Takashi Tanifuji

An optical pickup device is so configured as to change the propagating directions of light fluxes in four light flux areas defined in the periphery of an optical axis of laser light, out of the laser light reflected on a disc, to separate the four light fluxes one from the other. A signal light area where only signal light exists is defined on a detecting surface of a photodetector. Sensors for signal light is disposed at a position in the signal light area to be irradiated by the signal light, and a tracking error signal is generated based on a signal from the sensors. A direct-current component of the tracking error signal resulting from positional displacements of the sensors is cancelled by adjusting a gain of the signal from the sensor.

Optical pickup device and optical disc device

An information recording and reproducing apparatus for increasing a speed of tilt control, including a portion for storing reference data, a portion for storing sample values data, a portion for obtaining positional information, a stilt servo generator, a tilt adjuster.

Information recording and reproducing apparatus

The first layer (DVD layer) is first reproduced using the red layer light. Thereafter, search for the second layer (HDDVD layer) is performed with the blue laser light in accordance with the reproducing operation being temporarily interrupted for menu display (display for chapter or language selection). If the second layer is detected, a display indicating that the second layer can be selected is displayed over the menu display. If instruction to reproduce the second layer is input from the user according to the display, the reproducing operation of the first layer using the red laser light is switched to the reproducing operation of the second layer (HDDVD layer) using the blue laser light.

Optical disc device and disc reproducing method

When a disc loaded on a player is a hybrid next generation DVD, determination is made on whether the connected TV device is adaptable for the HD mode. Such determination is performed by whether or not the copyright protecting function of the connected TV device satisfies a condition set in advance. When adaptable for the HD mode, reproduction prioritizing the HDDVD layer is performed. When not adaptable for the HD mode, reproduction prioritizing the DVD layer is performed. Thus, the video content of HD mode recorded on the HDDVD layer is protected against leakage to the outside via the connected TV device by reproducing the DVD layer in preference in the case the copyright protecting function of the TV device is not sufficient.

Optical disc device

The present invention aims to smoothly and adequately adjust recording laser power while an increase in processing load during recording is suppressed. When a recording operation start request is received, OPC is executed with reference to a target &#x3b2; value (&#x3b2;t) of a disc to set recording laser power Pws. Recording operation is performed based on the set recording laser power Pws. When a system is brought into an intermittent standby state, R-OPC is executed, so the recording laser power Pws is adjusted and set again. Then, its subsequent recording operation is performed based on the recording laser power Pws which is set again. When a duration of the recording operation exceeds a maximal waiting time Ts, the recording operation is suspended so that the system is set to a recording standby state. Then, the R-OPC is executed, so that the recording laser power Pws is adjusted and set again.

Optical disc device for recording and reproducing information on and from a write-once-type disc using laser light

The number of recording layers of the loaded disc is determined using the blue laser light. If the number of recording layers is two, drawing is performed in the recording layer on the near side when seen from the laser light entering side, and demodulation is performed with the HDDVD decoder. If demodulatable, the disc is determined as a disc in which two HDDVD layers are arranged. If not demodulatable, determination is made on whether or not the data of the recording layer is demodulatable with the DVD decoder. If demodulatable with the DVD decoder, the laser light is switched to the red laser light and the number of recording layers is determined. If two recording layers are detected in this determination, the disc is determined as a disc in which two DVD layers are arranged. On the other hand, if one recording layer is detected, the disc is determined as a hybrid HDDVD in which one HDDVD layer and one DVD layer are arranged.

Optical disc device and disc determining method

In order to set optimum laser power for a disk smoothly and appropriately with a small number of times of test writing, an integrated value Sn is obtained from each kind of laser power Pwn set for the test writing and the modulation factor m(Pwn) of a reflection light intensity obtained through the test writing with the laser power Pwn using an expression 'Sn=m(Pwn)&#xd7;Pwn', laser power Pwth is obtained at which the modulation factor m(Pwn) becomes zero when relational characteristics of the integrated value Sn and the laser power Pwn are linearly approximated, and optimum laser power Pw is set based on the laser power Pwth. Here, the optimum laser power Pw is obtained from the target &#x3b3; value of the disk using an expression 'Pw=Pwth&#xd7;{1+1/(&#x3b3;+1)}'. The target &#x3b3; value is obtained from an ADIP of the disk.

Laser power adjustment method and optical recording and reproduction apparatus

An optimum power set value Pwpfor Layerobtained by an OPC is used as an initial value Pwof the OPC for Layer. At this time, an inclination Ia is obtained from an approximation line of a &#x3b2; value for Layer(recording power to the &#x3b2; value) obtained by the OPC. From the &#x3b2; value obtained by performing a test recording at the initial value Pwand the inclination Ia, an approximation line of a &#x3b2; value for Layer(recording power to the &#x3b2; value) is obtained. Then, on the obtained approximation line, a laser power for providing a target &#x3b2; value (&#x3b2;t) is obtained, and set as an optimum power Pwpfor Layer. Thus, an optimum power setting conforming to characteristics of a disc can be performed. As a result, setting the optimum power for Layercan be performed more smoothly and quickly.

Optical recording and reproducing apparatus

Laser power adjustment is performed using a power calibration area (PCA) until the PCA is used up. After the PCA is used up, an additional PCA is reserved at the next recording start position and laser power adjustment is performed using the additional PCA. When an additional PCA is reserved, the additional PCA exists between an information file recorded this time and the last one of information files recorded previously in terms of a physical format. However, information test-written into the additional PCA is not regarded as an information file and PMA information is generated only from the information file recorded this time by excluding the test-written information. As a result, a situation is obtained in which the additional PCA does not logically exist on the disk and there will never occur an inconvenient situation where the additional PCA is erroneously reproduced at the time of reproduction.

Provided is an optical disc device in which adjustment precision of recording laser power is improved without complication of a processing sequence during recording operation. In response to a recording start instruction, OPC is executed using an inner disc drive zone to set an initial value of recording laser power Pws. Then, when a first recording instruction REC(1) is detected, recording is successively performed from the head of a data area using the laser power Pws. After that, when an intermittent standby period is set, sample data is recorded to a next recording position and R-OPC is executed. Therefore, the recording laser power Pws is set again. Next, when a second recording instruction REC(2) is detected, recording is successively performed from a next recording position, that is, a position next to an end portion of the first recording instruction REC(1) using the reset laser power Pws. At this time, data corresponding to a head portion of the second recording instruction REC(2) is overwritten on sample data in the head of the recording position.

Provided is an optical disc device in which adjustment precision of recording laser power is improved without complication of a processing sequence during recording operation. In response to a recording start instruction, OPC is executed using an inner disc drive zone to set an initial value of recording laser power Pws. Then, when a recording instruction REC() is issued, recording is successively performed from the head of a data area using the laser power Pws. After that, when an intermittent standby period T is set, sample data is recorded at the number of times corresponding to the intermittent standby period T in a next recording position, and R-OPC is executed. Therefore, the recording laser power Pws is set again. Then, when a second recording instruction REC() is issued, recording is successively performed from a next recording position, that is, a position next to an end portion of data recorded by the first recording instruction REC() using the reset laser power Pws. At this time, data corresponding to a head portion of the second recording instruction REC() is overwritten on sample data in the head of the recording position.

A magneto-optical record medium and a reproducing apparatus for the same allow data reproduction having good characteristics by a simple structure. The magneto-optical record medium includes a plurality of first grooves ( ) each having sidewalls, at least one of which is wobbled in accordance with address information; an address mark ( ) formed by changing a width of a land located between second grooves connected to the first grooves; and third grooves wobbled cyclically, formed in a data portion magnetically storing data and connected to the second grooves. The reproducing apparatus reproduces the data from the magneto-optical record medium.

Record medium and reproducing apparatus of the same for detecting an offset correction

An magneto-optical disc recording/reproducing apparatus includes an optical head ( ) to detect a wobble ( ) and an address mark ( to ) in an magneto-optical disc ( ) and output a wobble signal (WB , WB ) and an address mark signal (AML, AMG), a PLL circuit ( ) to generate a clock signal (CK) in response to wobble signal (WB ), an address mark synchronous signal generation circuit ( ) to generate an address mark synchronous signal (AM) in response to address mark signal (AML, AMG), a synchronizing circuit ( ) to synchronize clock signal (CK) with address mark synchronous signal (AM) and generate a synchronized clock signal (SCK), and a timing setting circuit ( ) to generate a timing pulse signal (TG ) to control a magnetic head driving circuit ( ) and a timing pulse signal (TG ) to control a laser driving circuit ( ). The recording/reproducing apparatus can detect a address mark ( to ), record la data signal on magneto-optical disc ( ) in synchronization with the detected address mark, and reproduce a data signal from magneto-optical disc ( ) in synchronization with the detected address mark, so that the data signal can be surely recorded/reproduced.

Information recording/reproducing apparatus to record/reproduce information on a recording medium recorded with an address mark

A meandering groove is formed in a digital disk (,) with a wobble signal that is wobbled to reproduce a clock signal. The wobble signal is read out by an optical head (,). An address detection circuit (,) detects an address signal that is multiplexed with the wobble signal. A PLL oscillation circuit (,) provides a clock signal in synchronization with the wobble signal. Data is modulated by a modulation circuit (,) according to the clock signal and a timing signal based on the address signal, and recorded on the digital disk (,). In reproduction, a RF signal in the wobble signal is converted into a digital signal by an A/D converter (,). The signal is demodulated by a demodulation circuit (,) for data output.

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Mizuho, Japan

Noboru Mamiya