Sony Corporation

Sony Nec Optiarc Inc.

Mitsugu Imai

Junichi Horigome

Masayoshi Nagata

Satoru Higashino

Yuuichi Suzuki

Provided is a recording device, including a light irradiation/receiving unit that irradiates an optical recording medium with first light and second light, and that receives backpropagating light of the second light from the optical recording medium, a recording unit that carries out recording on the optical recording medium, a playback signal generating unit that obtains a playback signal of a signal, and a stray light signal component canceling unit that generates, based on recording data, a stray light cancel signal for canceling a stray light signal component.

Recording device and stray light signal component cancellation method

An information erasing device includes a recording section where recording is performed with regard to a disk-shaped recording medium, and a control section which controls the recording section so that the recording section overwrites a part of a erasing target sector so as not to overlap in a radius direction of the disk-shaped recording medium.

Information erasing device and information erasing method

A phase error detection apparatus includes: a sampling block; a first phase error calculation block; a second phase error calculation block; and a selective output block.

Phase error detection apparatus, phase error detection method, and reproduction apparatus

In a recording/reproducing system that performs PRML decoding, a suitable evaluation value for setting a recording condition can be obtained with a simple structure. It is assumed that a value corresponding to a difference between a difference metric between a maximum likelihood path for an equalized signal that is fed to maximum likelihood decoding processing and a path in a bit-advanced shift direction and a difference metric between the maximum likelihood path for the equalized signal and a path in a bit-delayed shift direction is a signal quality evaluation value dSAM. Further, the signal quality evaluation value dSAM is calculated using an equalization error value ek which is an error between an equalized signal value fed to the maximum likelihood decoding processing and an ideal equalized signal value determined from a decoded signal obtained as a result of the maximum likelihood decoding processing.

Recording/reproduction device, evaluation value calculation method, and evaluation value calculation device

In an information reproducing apparatus employing a maximum likelihood decoding method such as Viterbi decoding, there is a problem such that power consumption increases because a maximum likelihood decoding circuit is complicated, and many circuit elements must be used. A clock output control means is provided on a read clock transmission line of a maximum likelihood decoder, and no read clock is supplied to the maximum likelihood decoder in operation modes other than a specific operation mode when an input data is decoded by a Viterbi decoder, and thereby, it is possible to greatly reduce a power consumption. More specifically, in operation modes other than the read mode, the supply of read clock is stopped by the clock output control means based on a control signal from a controller for controlling an operation mode such as decoding or the like.

Information reproducing apparatus

A result of a blank/written identification performed concurrently with decoding is verified when an error occurs during decoding of read information, and retry is performed according to this identification result in order to achieve fast retry operation. Specifically, a blank check is performed concurrently with decoding of readout data so that when a decoding error occurs, the blank check status can be immediately identified. In this way, suitable retry operations can be undertaken.

Drive unit having blank/written area identification capability

In an optical recording a shape of a mark which is a data recording area can be formed into a desired shape even if a temperature of an optical recording medium changes. The present invention provides a temperature detecting means for detecting the temperature of the optical recording medium and a laser power adjusting means for adjusting first laser power and second laser power on the basis of the detected temperature, and the mark is recorded in the optical recording medium by using the adjusted first laser power and the adjusted second laser power. Thereby, even if the temperature of the optical recording medium changes with influence of environmental temperature, a recording operation can be performed with an optimum laser power determined based upon the temperature of the optical recording medium. Thus, even if the temperature of the optical recording medium changes, the shape of the mark which is the data recording area can be formed into the desired shape.

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Kanagawa, Japan

Mitsugu Imai