Sanyo Electric Co., Ltd.

Other

Ken Hirose

Noboru Mamiya

Kenji Nakao

Hiroshi Watanabe

Shuichi Ichiura

Naoyuki Takagi

Koichi Tada

Shinichi Ohe

Satoshi Sumi

Koichi Kawakami

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

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.

Optical disc device

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.

In order to reproduce signals from a double-layer optical disc having two signal recording surfaces, a focus jump that the focusing of an objective lens from the one signal recording surface to the other signal recording surface is quickly achieved, is necessary. When a focus error signal (FE) from a pickup ( ) reaches a predetermined threshold value (Vcomp), a deceleration signal for decelerating the objective lens ( ) is supplied to an actuator ( ). Preferably, a deceleration pulse voltage is lowered step by step. The deceleration pulse voltage is determined in accordance with the maximum value (DFEmax) of a differential focus error signal (DFE) generated by differentiating the focus error signal (FE). Preferably, the address seeking is done simultaneously with the focus jump. The focus jump is performed in accordance with the layer-to-layer distance which is measured beforehand. The focus jump is performed by using a lens ( ) having a controllable focal distance. Preferably, whether the layer is the first layer or the second layer is judged based on the reflected luminous power. If the focus error signal (FE) from the other layer is not obtained even when a certain time passages after the focus jump is started, the objective lens ( ) is moved in the reverse direction.

Growing community of inventors

Gifu, Japan

Ken Hirose