Hitachi-lg Data Storage, Inc.

Hitachi, Ltd.

Mitsuhiro Nishidate

Atsushi Yamada

Tooru Kawashima

Tomoya Hoshi

Tsuyoshi Toda

Koichiro Nishimura

Toru Kawashima

It is to provide an optical disc recording apparatus and a recording power control method that are adapted to high-speed recording and can set an optimal erasing power with high accuracy. A test writing signal detector reproduces a test writing signal of a predetermined mark length or space length with varied power, and detects the number of error mark signals and an amplitude value of an envelope. A controller obtains a first threshold Peof the erasing power based on the number of error mark signals in a region where laser power is low, and obtains a second threshold Peof the erasing power based on the amplitude value in a region where the laser power is high. Then, the controller sets an optimal value of the erasing power from an average value of the first and second thresholds.

Optical disc recording apparatus and recording power control method

The present invention makes it possible to reproduce reproduction images without a break without having to use any additional identification information even when real-time recorded data is not completely continuous. A control circuit references a data identification flag ('Recording Type') which is attached to each sector of reproduction data to indicate the type of recorded data, and counts the number of sectors to which the data identification flag representing real-time recorded data is attached. When the count is not smaller than a threshold value, the control circuit reproduces all the sectors of the target reproduction block in a real-time reproduction mode. In the real-time reproduction mode, the control circuit masks a portion of reproduction data that is found to be defective, changes the value of the defective data to 0 (zero), and transfers the resulting reproduction data to a host device.

Optical disc apparatus and reproduction control method

An optical disc apparatus capable of improving an overwrite performance for performing an overwrite operation on a re-writable type optical disc. The apparatus includes a calculating section which calculates out a recording power at the time of previously performing recording in a recording area of the optical disc, and a recording power determining section which determines a write power of the recording power calculated out by the calculating section as a write power of the currently recorded recording power, and at the same time, adjusts erase power, cooling power, and/or middle power of the recording power calculated out by the calculating section to finally determine the currently recorded recording power.

Optical disc apparatus and method for controlling overwrite power

Growing community of inventors

Sagamihara, Japan

Mitsuhiro Nishidate