Fujitsu Corporation

Akira Nanba

Masakazu Taguchi

Kenichi Hamada

Toru Fujiwara

Toru Ikeda

Shigeyoshi Tanaka

Satoshi Furuta

Takanobu Kashiwagi

Masahiko Katada

Kenichi Ogura

Yukio Sekiguchi

Manabu Ogino

Katsufumi Onaka

Eiji Kaneko

The present invention relates to protection of accommodated items such as cartridges each incorporating recording media and enhances a protection function for the accommodated items. The present invention relates to protection of accommodated items accommodated in an accommodating shelf into/out of which accommodated items (cartridges) such as cartridges each incorporating recording media such as magnetic tapes can be put/taken. The present invention includes guard bars (longitudinal bars BV and lateral bars BL) that are disposed on or in front of entrance/exit portions of a plurality of cells that accommodate the accommodated items and that obstruct putting in/taking out of the accommodated items, and the present invention includes a structure that enables loading in or loading out of the accommodated items by moving guard bars corresponding to a cell into/out of which the accommodated item is loaded, from a closed position to an opened position and that, after the loading in or the loading out, protects the accommodated item by moving the guard bars from the opened position thereof to the closed position. Thereby, the protection of the accommodated items is facilitated by a simple structure.

Apparatus, method and program for protecting accommodated item such as cartridge

A data recording method for calculating a digital sum value (DSV) corresponding to a proportion of positive data and negative data included in predetermined data ranges, selecting a resync pattern to be inserted between the data ranges according to the DSV, and inserting the selected resync pattern between the data ranges, has a step of selecting a resync pattern that minimizes differences in DSV between the data ranges.

Data recording method, data reproduction method, data recording device, data reproduction device and optical recording medium

The digital phase locked loop circuit according to the invention includes a GAC circuit () for calculating the average frequency of the phase locked sampling clock signals in selected channels and for feeding back the calculated average to the phase locked loop. The GAC circuit () includes comparators () for comparing the frequency of the sampling clock signals in each channel with an allowable frequency range and for outputting a frequency error signal with respect to any channel in which the frequency of the sampling clock signals is outside the allowable frequency range.

Digital phase lock loop circuit

Data recording method and apparatus for reducing fluctuation in DC component

A data reproduction apparatus that employs an expected value generation unit that employs a maximum likelihood decoding algorithm, thereby an expected value is correctly determined from a histogram of sampled values of a signal to be reproduced, even when an offset arises in the signal to be reproduced, the offset being removed from the sampled values used in generating a histogram that is used to determine the expected value.

Expected value generation unit and a data reproduction apparatus

The present invention realizes stable and more proper data reproduction even when a reproduced signal varies locally due to a noise or includes a steady distortion. In a data reproduction control method and apparatus, and an optical disk unit that adjust sampled values, in sampling a signal reproduced from a recording medium recorded with data, the frequencies of the levels of quantized data are counted, a histogram of the frequencies of the levels is created based on the counting results, and more accurate reproduced data is obtained by means of a distribution of the frequencies of the levels in the histogram.

Data reproduction control method and apparatus, and optical disk unit

A data reproduction device includes an A/D converter quantizing a reproduction signal read from data recorded on a recording medium to produce quantized data based on a sampling clock; a reproduction signal determination unit determining rising and falling parts of the reproduction signal based on the quantized data, and outputting a gate signal corresponding to a result of determining the rising and falling parts; a leading-edge clock generation unit generating a leading-edge clock signal synchronous to a leading edge indicating a rising part of the reproduction signal; a trailing-edge clock generation unit generating a trailing-edge clock signal synchronous to a trailing edge indicating a falling part of the reproduction signal; a signal switch unit generating the sampling clock by selecting one of the leading-edge clock signal and the trailing-edge clock signal based on a value of the gate signal; and a signal supply unit supplying the sampling clock to the A/D converter, wherein the data reproduction device reproduces the data recorded on the recording medium by executing digital signal processing on the quantized data. The data reproduction device can share a single A/D converter and a single decoder used for reproducing recorded data based on clocks synchronous to a leading edge and a trailing edge of the recording pit. As a result, a circuit structure of the data reproduction device is simplified, thereby achieving decreases in a size of an implementation area and in the number of implemented parts in the circuit structure of the data reproduction device.

Data reproduction device with simplified circuit structure

A data reproduction device reproduces the data recorded on the recording medium by executing digital signal processing on the quantized data. The data reproduction device can share a single A/D converter and a single decoder used for reproducing recorded data based on clocks synchronous to a leading edge and a trailing edge of the recording pit.

There is provided an optical storage device that can position a lens carriage and objective lens even when position sensors for the lens carriage and objective lens are excluded in an effort to make an optical disk unit thinner. In the optical storage device, immediately after an optical disk is loaded in a main body, the cutoff frequency of a filter lying on a path of a reproduction signal is temporarily changed to a lower frequency. A spacing of sectors of the optical disk is detected using a signal sent from the filter. A type of an optical storage medium and a position of a current reproduction track are detected on the basis of the detected sector spacing and data stored in a memory.

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Kato, Japan

Akira Nanba