Abstract: A reproducing and recording apparatus, a decoding apparatus, a recording apparatus, a reproducing and recording method, a decoding method and a recording method are provided in which a computation for changing acoustic characteristics of compressed digital data is effected on a scale factor of each divided band in the compressed digital data including spectrum data band-divided into a plurality of bands on a frequency axis and the scale factor of every divided band.

Abstract: A semiconductor laser driving apparatus for directing light to an optical disc for recording a recording mark based on a recording current and reproducing the recording mark to generate a reproduction signal. The apparatus includes a reproduction current generation section; a high frequency current generation section for generating a current including a high frequency component for reducing semiconductor laser noise in the reproduction; a recording current generation section, the recording current including a pulse corresponding to the recording mark and including a plurality of multi-pulses; and a current driving section for amplification. The apparatus further includes a filter to attenuate the enhanced high frequency components in the high frequency current and in the enhanced high frequency component; and a switching section for switching the filter so that the enhanced component in the recording current is superposed on at least one of the multi-pulses.

Abstract: A reproducing and recording apparatus, a decoding apparatus, a recording apparatus, a reproducing and recording method, a decoding method and a recording method are provided in which a computation for changing acoustic characteristics of compressed digital data is effected on a scale factor of each divided band in the compressed digital data including spectrum data band-divided into a plurality of bands on a frequency axis and the scale factor of every divided band.

Abstract: A reproducing and recording apparatus, a decoding apparatus, a recording apparatus, a reproducing and recording method, a decoding method and a recording method are provided in which a computation for changing acoustic characteristics of compressed digital data is effected on a scale factor of each divided band in the compressed digital data including spectrum data band-divided into a plurality of bands on a frequency axis and the scale factor of every divided band.

Abstract: Data read from a disk is input to an RF amplifier. An RF amplifier generates, based on bit data, an RF signal constituted by a plurality of components of mutually different frequencies. The RF amplifier determines a relation between the frequencies and gains on the basis of a control clock and adjusts the gains of respective components in the RF signals on the basis of the relation (equalize-processing). A PLL circuit has a first VCO and first frequency divider to generate a bit clock and generates, on the basis of an output signal of a data slice circuit, a first control voltage for controlling the first VCO. The first control voltage, being passed through a lowpass filter, is converted to a second control voltage for controlling a second VCO. The second VCO has an arrangement and characteristic substantially the same as those of the first VCO.

Abstract: An equalizer used for an optical reproducing apparatus performs an optimal equalizing operation in accordance with the spatial frequency without needing an electrical equalizer. The optical reproducing apparatus reproduces the reproducing data in the following manner. A detector is provided for receiving reflected light from a disc. The detector is divided into a plurality of light receiving areas by a line perpendicular to the light receiving direction corresponding to the disc track direction. Then, calculations are made on the outputs from the respective light receiving areas to specifically correct the spatial frequency characteristics. The calculated signal is then decoded.