Sony Corporation

Futoshi Tsukada

Tetsuji Kawashima

Kunihiko Miyake

Michihiko Iida

Eiji Kumagai

Yukio Shishido

Kenji Nagashima

Norio Nishida

Shinji Ohta

Masazumi Shiozawa

An optical disc having a power calibration area for calibrating the power of a data recording laser beam. The power calibration area is provided at an inner peripheral part of the disc and has test areas and count areas. The test areas are provided to accomplish trial writing of data, and the count areas are provided to record data representing the use condition of the test areas. Data is recorded on the optical disc, while calibrating the data recording laser beam. The number of the test areas is increased in accordance with an increase in the recording density of the optical disc. The optical disc may be a double-density CD. In this case, the disc has 800 to 1200 test areas. The test areas have the smallest possible size, and the count areas are provided in the smallest possible number. Therefore, the disc can have sufficiently large data regions. Thus, the power of the data recording laser beam can be therefore adjusted many times. The amount of data that can be recorded on the optical disc therefore increase.

Optical disc, data-recording apparatus and data-recording method

Physical addresses of the recording areas provided on an optical disc are represented in a time-axis data format and in a binary data format. The physical address value gradually increases from the inner part of the disc to the outer part of the disc, while the formats remain in one-to-one correspondence over the recording areas. The distance the optical head must move to reach a target recording area can therefore be calculated easily independently of where on the disc the optical head is located, enabling the optical head to quickly access the target recording area.

Optical disc and optical disc apparatus

A method and apparatus for information signals in which, in recording and/or reproducing information signals responsive to a request from a host device, a first address defined with the time domain information is converted into a second address defined with consecutive hexadecimal numbers and vice versa by way of reciprocal address conversion. Specifically, an uppermost order value in the time domain information in the first address and a second address value are converted reciprocally using a conversion table.

Recording and/or reproducing method and apparatus having reciprocal time domain to binary conversion means

An optical disc having a data area in which information signals are recorded, a lead-in area and a lead-out area provided before and after the data area, and a program memory area for temporarily storing address information necessary for additionally writing information signals. A subcode Q of the lead-in area or a subcode Q of the program memory area is provided with identification information for identifying these subcodes Q. For example, the identification information is provided at least in one of address (ADR), track number (TNO), and zero (ZERO) constituting the subcode Q of the program memory area or the lead-in area. Thus, it is possible to discriminate the subcode Q of the program memory area and the subcode Q of the lead-in area securely and instantaneously.

Optical disc and optical disc driving device

A laser light beam is illuminated via an objective lens on the signal surface of an optical disc and the objective lens is displaced by a servo processor along the optical axis for focussing search to generate focussing error signals by a RF block from a detected output of the laser light by the signal surface of the optical disc. Based on these focussing error signals, a system controller discriminates the types of the optical disc having different numbers of signal recording layers for setting an operating mode in keeping with the types of the optical disc.

Optical disc device and optical disc discriminating method

An optical disc apparatus using zone record system that successively records data in a plurality of zones without a time lag in switching zones is disclosed. A phase error signal is formed with a reproduced signal of a servo zone of an optical disc 1. A servo clock is generated by a servo PLL 8. Data PLLs 9a and 9b divide the frequency of the servo clock. The laser power of the servo zone is detected by a circuit 11a so as to perform a read ALPC operation. The record laser power is detected by a circuit 11b so as to perform a write ALPC operation. A DSP 14 compares the monitor values and a reference value and controls a bias value of the drive signal so that the detected value becomes equal to the reference value. In write mode, a laser device emits pulse laser light in response to the data clock. Since the write ALPC operation is performed for the next zone while it is performed for the present zone, one of the PLLs 9a and 9b generates data clock for the present zone. The other generates the data clock for the next zone. These data clocks are selectively supplied to the laser device.

Growing community of inventors

Kanagawa, Japan

Futoshi Tsukada