Write control method and apparatus for writing optical disk data
AssigneeFujitsu Limited
InventorsSeiichi Iwasa, Nagaaki Koshino, Kenichi Utsumi, Masahiro Nakada
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Abstract
A write control method for writing optical disk data wherein pits are written by a write signal composed of mark signal parts and space signal parts, and a length of each pit represents the optical disk data, comprising the steps of: converting the mark signal parts to pulses and generating a series of pulse trains which correspond to lengths of the mark signal parts, respectively; controlling a lengths and/or amplitude of each of the pulse trains in accordance with a length of the space signal part immediately before the mark signal part; and applying successively the controlled pulse trains to a laser irradiation device so that the pits are written.
Claims28
A write control method for writing data represented by pit length on an optical disk medium using a laser in accordance with a write signal that includes mark signal parts each having a first length and space signal parts each having a second length, comprising the steps of:
- (a) converting the mark signal parts to pulses;
- (b) generating from the pulses a series of pulse trains which respectively correspond to the first lengths of the mark signal parts;
- (c) recognizing the second length of one of the space signal parts immediately before one of the mark signal parts in real time, at an end of the one of the space signal parts, to produce a recognition result;
- (d) controlling at least one of a length and an amplitude of each of the pulse trains in accordance with the recognition result obtained in said step (c);
- and
- (e) writing the data to the optical disk medium by applying successively the pulse trains controlled in step (d) to the laser.
A write control method for writing data represented by pit length on an optical disk medium using a laser in accordance with a write signal that includes mark signal parts each having a first length and space signal parts each having a second length, comprising the steps of:
- (a) dividing each of the mark signal parts into three parts including a start part, an intermediate part and an end part;
- (b) elevating the temperature of the optical disk medium to a writable temperature in dependence upon the start part;
- (c) maintaining a balance between the temperature of the optical disk medium and heat radiation from the optical disk medium in dependence upon the intermediate part;
- (d) maintaining a decrease in the temperature of the optical disk medium in dependence upon the end part;
- (e) converting the three parts of each of the mark signal parts to pulses having pulse widths set for said elevating, maintaining a balance and maintaining a decrease, respectively;
- (f) generating from the converted pulses a series of pulse trains which correspond to respective first lengths of the mark signal parts;
- (g) varying the number of pulses of the intermediate part of one of the mark signal parts to correspond to the first length of the one of the mark signal parts;
- (h) controlling at least one of the length and amplitude of each of the pulse trains in accordance with the second length of one of the space signal parts immediately before the one of the mark signal parts;
- and
- (i) applying successively the pulse trains controlled in step (h) to the laser to write on the optical disk medium.
A write control method for writing data represented by pit length on an optical disk medium using a laser in accordance with a write signal which includes mark signal parts each having a first length and space signal parts each having a second length, comprising the steps of:
- (a) converting the mark signal parts to pulses;
- (b) generating from the pulses a series of pulse trains which respectively correspond to the first lengths of the mark signal parts;
- (c) recognizing the second length of one of the space signal parts immediately before one of the mark signal parts at an end of the one of the space signal parts in real time, to produce a recognition result;
- (d) time condensing a part or whole of each of the pulse trains in accordance with a second length of one of the space signal parts immediately before one of the mark signal parts;
- and
- applying successively the pulse trains time condensed in step (d) to the laser.
A write control apparatus for writing data represented by pit length on an optical disk medium using a laser to irradiate the optical disk medium in accordance with a write signal generated in write signal cycles using a basic clock and comprising mark signal parts each having a first length, and space signal parts, each having a second length, comprising:
- first delay means for delaying by a first predetermined range each of the mark signal parts and for providing a first delayed signal based on the delaying by the first predetermined range;
- second delay means for delaying the first delayed signal by a second predetermined range and for providing a second delayed signal based on the delaying by the second predetermined range;
- control signal generating means for generating a start part control signal, an intermediate part control signal and an end part control signal based on the first and second delayed signals and the corresponding one of the mark signal parts;
- pulse forming means for converting each of the start part control signal, intermediate part control signal and end part control signal to a pulse or pulses, and for generating a series of pulse trains which respectively correspond to the first lengths of the mark signal parts by combining the pulse or pulses converted from each of the control signals;
- and
- pulse train control means for controlling at least one of the length and the amplitude of each of the pulse trains in accordance with the second length of one of the space signal parts immediately before each of the mark signal parts.
A write control apparatus for writing data represented by a pit length on an optical disk medium of the optical disk memory in accordance with a write signal comprising mark signal parts each having a first length, and space signal parts each having a second length, comprising:
- pulse forming means for converting the mark signal parts to pulses and for generating a series of pulse trains which correspond to the first lengths of the mark signal parts, respectively;
- space recognition means for recognizing the second length of one of the space signal parts immediately before one of the mark signal parts at one end of the one of the space signal parts in real time and for providing a result based on the recognizing;
- and
- time condensation means for time condensing at least part of each of the pulse trains in accordance with the recognition result so that a position of an end pulse of the pulse train becomes the same position.
A write control apparatus for writing data represented by pit length on an optical disk medium using a laser in accordance with a write signal including mark signal parts each having a first length and space signal parts each having a second length, comprising:
- dividing means for dividing each of the mark signal parts into three parts including a start part, an intermediate part and an end part;
- pulse converting means for converting the three parts of each of the mark signal parts to pulses;
- temperature control means for elevating the temperature of the optical disk medium to a writable temperature in dependence upon the start part, for maintaining a balance between the temperature of the optical disk medium and heat radiation from the optical disk medium in dependence upon the intermediate part and for maintaining a decrease in the temperature of the optical disk medium in dependence upon the end part;
- pulse train generating means for generating from the pulses a series of pulse trains corresponding to respective first lengths of the mark signal parts;
- and
- pulse controlling means for varying a number of pulses of the intermediate part of one of the mark signal parts in dependence upon the first length of the one of the mark signal parts, and for controlling at least one of the length and amplitude of each of the pulse trains in dependence upon the second length of one of the space signal parts immediately before the one of the mark signal parts.
Dependencies are inferred from the claim text.