Hitachi, Ltd.

Hitachi-lg Data Storage, Inc.

Other

Hitachi Software Engineering Company, Ltd.

Shigeki Yamazaki

Hisataka Sugiyama

Toshimitsu Kaku

Tsuyoshi Toda

Tetsuya Fushimi

Hiroyuki Minamura

Makoto Itagaki

Motoyuki Suzuki

Tomomi Okamoto

Toshio Saitoh

Jinya Ikeda

Kazuki Nakazawa

In a three-wavelength-compliant optical disk apparatus, the present invention enables to shorten time required for starting the apparatus such as discrimination of an optical disk and adjustment of a beam-expander. At the time of starting the apparatus, the operation of a tray driver which pulls a loaded optical disk within the apparatus is conducted in parallel with the operation of a beam-expander driver which allows a movable lens of the beam-expander to move to a predetermined position in accordance with the kind of optical disk. Further, at the time of discriminating the disk, the number of times an optical disk of a specific kind has continuously been loaded into the apparatus to date is stored in a memory, and a sequence of discriminating the kind of optical disk that is newly discriminated is switched by referring to the history information.

Optical disk apparatus and starting method thereof

The present invention provides an optical disc apparatus that reduces access time while suppressing the emanation of heat from a beam expander. A microcomputer manages the operation time and pause time of a stepping motor constructed to move the movable lens of the beam expander, and in accordance with the duration of an immediately previous pause, limits the number of successive stepping-motor driving actions following the pause time, below a maximum permissible count. When the pause duration is shorter than a threshold value or when the number of successive stepping-motor driving actions reaches the maximum permissible count, the microcomputer starts next driving of the stepping motor after a required waiting time.

Optical disc apparatus and control method thereof

An optical disc apparatus and method for recording and reproducing information to/from an optical disc, including discrimination of the optical disc, reading control information in an un-recordable area formed in an inner periphery of the optical disc, conducting focus control based on a focus error signal in a recordable area formed outside of the un-recordable area, and determining an optimum offset value of the focus error signal in the recordable area. Further, adjustment in amplitude of a reproduced signal from an inner periphery of the recordable area is conducted, test-writing in the inner periphery of the recordable area is conducted, test-writing in an outer periphery of the recordable area is conducted, and adjustment in amplitude of a reproduced signal from the outer periphery of the recordable area is conducted. The respective operations are conducted sequentially so as to make the optical disc in a reproducible and recordable condition.

Optical disc apparatus and method thereof

An optical disc apparatus having at least two optical condenser lens for recording and reproducing information of an optical disc, comprising: means for discriminating the optical disc; means for reading control information in a ROM area which is formed in an inner periphery of said optical disc; means for conducting focus control in a RAM area which is formed outside of said ROM area; means for conducting adjustment in amplitude of a reproduced signal from an inner periphery of said RAM area; means for conducting a pre-writing (a sample-writing); means for conducting test-writing in the inner periphery of said RAM area; means for conducting test-writing in an outer periphery of said RAM area; and means for conducting adjustment in amplitude of a reproduced signal from the outer periphery of said RAM area, wherein said means conducts the respective operations sequentially, thereby making said optical disc in reproducible and recorable condition, with a short time period and with a smooth confirmation operation.

The device seeks to improve the reliability of information and to increase recording capacity by controlling the recording mark to be recorded on the recording medium with high preciseness. To improve the conformity of a recording medium with a device that records, retrieves and erases information, a recording pulse train is generated by a test write data generating circuit,and a recording pulse forming circuit,and a recording mark is recorded on a recording medium,by a laser driver,Excessive power recording is reduced, an optimum recording power is determined and regular information recording and retrieving is carried out by detecting a test write data from a test write data detecting circuit,to which the retrieved signal from the recording medium,is input. Based upon analysis of the retrieved signal by a controller,and the range of next power scan is changed so as to avoid excessive power recording while making it possible to determine the optimum recording power.

Optical disk recording and retrieving device

The device seeks to improve the reliability of information and to increase recording capacity by controlling the recording mark to be recorded on the recording medium with high preciseness. To improve the conformity of a recording medium with a device that records, retrieves and erases information, a recording pulse train is generated by a test write data generating circuit 18 and a recording pulse forming circuit 15 and a recording mark is recorded on a recording medium 5 by a laser driver 14. Excessive power recording is reduced, an optimum recording power is determined and regular information recording and retrieving is carried out by detecting a test write data from a test write data detecting circuit 12 to which the retrieved signal from the recording medium 5 is input. Based upon analysis of the retrieved signal by a controller 19, and the range of next power scan is changed so as to avoid excessive power recording while making it possible to determine the optimum recording power.

Growing community of inventors

Matsudo, Japan

Shigeki Yamazaki