US 4,788,674 A · Optical disc record reproducing apparatus

Abstract

An optical disc apparatus provided with a recording correcting system for controlling variations in the recorded bit length. The recording correcting system may be controlled not only while the apparatus is put to work, but also during unoccupied times when the recording, reproducing, and erasing operations are not required from a higher level apparatus. Also, the controlling operation may be performed so that the value of the record correction may be renewed at proper time intervals. The repetition of the correction trial at the proper interval allows a time lapse after the apparatus power-supply is put to work to occur with no undesirable effects and the characteristic variation between respective discs during the disc exchange can be coped with.

Claims8

Dependent claims

An optical disc recording and reproducing apparatus, comprising:

laser beam generating means for producing laser beams of variable power;
recording means for recording information bit signals in the form of bits on an optical disc using laser beams of sequentially varied power produced by said generating means over a plurality of predetermined time periods;
and
power detecting means for detecting an optimal laser beam power, including
means for producing information pulse signals corresponding to the bits recorded by said recording means over said plurality of time periods,
means for comparing pulse widths of said information pulse signals with a reference pulse width and producing an output signal when said information pulse widths are at least equal to said reference pulse width, and
means responsive to the output signal from said comparing means for determining the optimal laser beam recording power.

4 more elements

Dependencies are inferred from the claim text.

Optical disc record reproducing apparatus

Life of this patent

Optical disc record reproducing apparatus

Life of this patent

Abstract

Claims8