JPS59227040A - Optical storage writing circuit - Google Patents

Abstract

PURPOSE:To reduce an average power of a recording current supplied for forming a bit, and to attain a long-lived optical recording head by changing a current supplying part, and forming only the leading edge and the trailing edge of a bit formed in an optical storage medium, by an optical output of a large power. CONSTITUTION:This write data (a), first of all, is delayed by a time T1 by a delaying circyit 3, becomes a write indicating signal (b), and it is supplied to AND circuits 5, 8, a delaying circuit 6 and a current switching circuit 12. A trailing edge pulse signal (c) and a leading edge pulse signal (e) are subjected to the sum by an OR circuit 9, become a power-up indicating signal (f), and it is inputted to a current supplying circuit 10. The current supplying circuit 10 operates so as to output a power-up current I1 only when the power-up indicating signal (f) is inputted, and on the other hand, a current supplying circuit 11 outputs a constant current I2. This power-up current I1 and the constant current are added, suppied as a write current (h) to the current switch 12, and by this switch, a recording current (g) is outputted only while the write indicating signal (b) is logical ''1''.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical storage write circuit, and more particularly to an optical storage write circuit for recording digital information onto a disk-shaped optical storage medium by optical means.

Generally, optical storage devices such as optical disk devices use laser light as a writing means.The laser light is focused into a very small light spot using an optical lens, and the energy is used to form bits on the optical storage medium. The information is recorded.

FIG. 1 is a relationship explanatory diagram for explaining the relationship between write data and pits on an optical storage medium in the present invention and a conventional optical storage write circuit.
MFM) shows the relationship between write data a and pit 2 on the optical storage medium in the recording modulation method.
It is important how accurately the end of the bit 2 is formed.

However, now the interval between the presence or absence of bits in write data a is l:
Even if the duty ratio is 50%, which corresponds to
Since it is affected by the relative speed between the optical storage medium and the optical recording head, the leading and trailing ends of bit 2 are not steep and the effective duty deviates from 50%.

This shift in duty ratio results in a shift in the data bit position during data reproduction, that is, a pit shift, which lowers the data discrimination margin and causes reading errors.

The above-mentioned duty ratio deviation on the optical storage medium is generally caused by
This can be improved by increasing the recording power, but on the other hand, semiconductor lasers are used as laser light sources in optical disk devices due to the need for smaller devices, but these semiconductor lasers should be used at the lowest possible power due to longevity issues. is desired.

A conventional optical recording write circuit includes a write instruction generator that generates a write instruction signal that instructs the formation of bits on an optical recording medium in response to all write data, and outputs a write current of a predetermined power. a current supply section; a current switch circuit that outputs the write current as a recording current when the write instruction signal is supplied; and a current switch circuit that outputs the write current as a recording current when the write instruction signal is supplied; and an optical recording head for forming the recording head.

In other words, in conventional optical storage writing circuits, a semiconductor laser is used as a laser light source due to the demand for miniaturization of optical disk devices, and semiconductor lasers are desired to be used at the lowest possible power due to longevity issues, so the power consumption of semiconductor lasers is relatively low. A recording current of a predetermined constant power is used, and a shift in duty ratio is offset by changing the duty ratio of write data.

However, since the power of the recording current is not sufficient, there is a drawback that the duty ratio fluctuates due to differences in medium characteristics or differences in relative speed due to track positions given in the radial direction on the disk.Also, the waveform of the recording current is Since it is a rectangular wave, changing the duty ratio of the write data essentially increases the average power.9 It does not contribute to extending the life of the semiconductor laser, and has the disadvantage that the life of the optical recording head is short. Ta.

An object of the present invention is to provide an optical storage write circuit that can extend the life of an optical recording head.

That is, an object of the present invention is to improve the above-mentioned drawbacks of the prior art, reduce fluctuations in duty ratio due to changes in medium characteristics or relative speed, and reduce average power to improve optical recording heads including semiconductor lasers. An object of the present invention is to provide an optical storage writing circuit that can improve the lifespan of an optical storage device.

The optical storage write circuit of the present invention generates a write instruction signal instructing the formation of a hit on an optical recording medium in accordance with write data, and also generates the write instruction signal at the front and trailing edges of the write instruction signal. a write instruction generation unit that outputs a power-up instruction signal;
a current supply unit that outputs a write current having a power greater when the power-up instruction signal is supplied (than a predetermined power output when the power-up instruction signal is not supplied); A current switch circuit that outputs the write current as a recording current when an instruction signal is supplied, and an optical recording head that forms pits on the optical recording medium by outputting light according to the recording current. It consists of:

That is, the optical storage writing circuit of the present invention is an optical storage writing circuit for recording a 2-speed digital signal on an optical storage medium in accordance with the presence or absence of optical output, and includes: It has a first nozzle level and a second nozzle level (which is smaller than the first nozzle level), and the first / It is configured to perform recording with a recording power and a waveform having a lower power level and a lower waveform having a smaller second power level except at the trailing edge of mJ.

That is, the optical storage write circuit of the present invention has two power levels of the recording current: a first power level and a second power level that is smaller than the first power level, and When forming the recording current, the waveform of the recording current has a first power level at the front and rear edges corresponding to the start and end of the optical output (double irradiation), and a second power level with a small power level at areas other than the front and rear edges. configured to have a power level.

Next, embodiments of the present invention will be explained with reference to the drawings.
do.

FIG. 2 is a block diagram showing an embodiment of the present invention, and the optical storage write circuit shown in FIG. It is composed of a recording head 13. Here, the write instruction generating section A includes delay circuits 3 and 6, inverter circuits 4 and 7, and an AND circuit 5.
, 8 and an OR circuit 9, and the current supply section A includes current supply circuits 10 and 11. Further, the optical recording head 13 includes a semiconductor laser diode 14 and a storage medium 1.
A light output P is supplied to 5.

FIG. 3 is an operational waveform diagram of each part in the embodiment shown in FIG. 2.

Next, the operation of the optical storage write circuit shown in FIG. 2 will be explained with reference to FIG. 3.

Although the write data a shows a waveform generated using a modified FM (MFM) recording modulation method, it is not particularly limited to this method.

This write data ali is first set by the delay circuit 3 for a time T
The write instruction signal is delayed by 1, and the AND circuit 5
, 8, the delay circuit 6 and the current switch circuit 12. Since one input of the AND circuit 5 is supplied with a signal with the reverse polarity of the write data a by 4, the trailing edge pulse signal C, which is the output of the AND circuit 5, is a write instruction signal. The signal has a pulse width of time T1 at the trailing edge of the signal. Furthermore, one input of the AND circuit 8 is supplied with the delayed signal d, which is obtained by delaying the write instruction signal S by the time T2 in the delay circuit 6, after the polarity has been reversed in the circuit 7. The leading edge pulse signal e, which is the output of the circuit 8, has a pulse width of time T2 at the leading edge of the write instruction signal.

The trailing edge pulse signal C and the leading edge signal (the pulse signal e are summed by the OR circuit 9) become a war-up instruction signal f,
A current supply circuit 10g is input.

'WL flow supply circuit IO operates to output power-up current II only when power-up instruction signal f is input, while current supply circuit 11 outputs constant current I2. This power-up 1[fi Ii and the constant current are added together and supplied as a write current to the current switch 12, where the recording current g is output only during the logic *i n of the write instruction signal.

Thereafter, the recording current g is supplied to the semiconductor laser diode 14 in the optical recording head 13 and becomes an optical output p, which is converged by the optical lens of the optical recording head 13 and onto the rotating optical storage medium 15. irradiation, and pits 2 are formed.

Since the optical output p output from the semiconductor laser diode 14 is proportional to the supplied recording current g, the power level is a first power level P1 corresponding to the current (If +I2) and a second power level P1 corresponding to the current IgK. There is a power level P2, and when forming bit 2, a large power level P1 is irradiated onto the optical storage medium 15 between time T2 corresponding to the leading edge of bit 2 and time T1 corresponding to the trailing edge of bit 2. Areas other than the edges will be irradiated with a small power level P2.

According to the above embodiment, near the boundaries between the presence and absence of pits, which are information points, are recorded with a large power, so the data-to-tea ratio is improved, and fluctuations in the data-to-tea ratio due to changes in medium characteristics or relative speed. is also reduced. The improvement effect of this duty ratio is considered to be equivalent to the case of uniform irradiation at a large power level P1 in the conventional technique, so conversely, the same duty ratio can be obtained with a smaller average power than in the conventional technique. It also becomes.

Furthermore, when a method of correcting the shift in duty ratio by changing the duty ratio of write data is also used, there is an advantage that the amount of increase in average power can be reduced because the irradiation time only increases at a small power level P2. .

The optical storage writing circuit of the present invention changes the current supply unit to form only the leading and trailing edges of the pits formed in the optical storage medium with high power optical output, thereby forming bits. Since the average power of the recording current supplied can be reduced, this has the effect of extending the life of the optical recording head.

In other words, the optical storage write circuit of the present invention has the power of the recording current at a small power level at the leading and trailing edges and a small power level at areas other than the leading and trailing edges. This has the effect of improving duty ratio deviations caused by changes in medium characteristics and relative speed.

[Brief explanation of drawings]

FIG. 1 is a relationship explanatory diagram for explaining the relationship between write data and pits on an optical storage medium in the present invention and a conventional optical storage write circuit. FIG. 2 is a block diagram showing an embodiment of the present invention. 3 are operation waveform diagrams of various parts in the embodiment shown in FIG. 2. A: Write instruction generation unit, B: Current supply unit, 2: Bit, 3, 6: Delay circuit % 4, 7: ...Inverter circuit, 5, 8-
...AND circuit, 9...OR circuit, 10
, 11... Current supply circuit, 12... Current switch circuit, 13... Optical recording head, 14
... Semiconductor laser diode, 15...-
- Optical storage medium, a...Write data, b...Write instruction signal, C... Trailing edge pulse signal, d...Delay signal, e... Leading edge pulse signal, f...
・Power-up instruction signal, g --- Recording current, h
・・・−・Write current, p・group・light output.

Claims (1)

[Claims] A write instruction generation unit that generates a write instruction signal that instructs the formation of pits on the optical recording medium in accordance with write data, and outputs a power-up instruction signal that is generated in the pre-spinning and post-spinning of the write instruction signal. a current supply unit that outputs a write current having a power greater than a predetermined power output when the power-up instruction signal is not supplied when the power-up instruction signal is supplied; A current switch circuit that outputs the write current as a recording current when an instruction signal is supplied, and an optical recording head that forms pits on the optical recording medium by outputting light according to the recording current. An optical memory writing circuit featuring: