JPS63229625A - Optical disk device - Google Patents

Abstract

PURPOSE:To reduce the degradation of disk materials due to repeated use of the same position in a sector and to increase the number of times of repeated use by providing a means which varies the recording start point in the sector at random. CONSTITUTION:A D-type flip-flop (D-FF) 11 latches a pulse SPD from a delay circuit 3 as the data input and sends an output Q to a data generating circuit 4 as a start pulse STP. The D-FF 11 delays the start pulse STP at random by the period of a clock input CK1 oscillated asynchronously with the data input SPD. Consequently, the data generating circuit 4 simultaneously generates recording data WDT, where the start pulse STP is delayed at random, and a recording gate WDT to vary the recording start point in the sector. Thus, the degradation of disk materials due to repeated use in the same position in the sector is reduced to increase the number of times of repeated use.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an optical disc device, and specifically, irradiates an optical disc with a laser beam having a diameter of about 1 μm,
The present invention relates to a rewritable optical disk device that can repeatedly record and reproduce signals by recording and reproducing signals at high density and erasing once recorded signals by laser irradiation.

Recording in a conventional optical disc apparatus is performed by modulating the intensity of a laser beam using a signal indicating a recording section and recording data.

An example of the above optical disc device is shown in FIG. In the figure, 1 is an address reproducing circuit, which receives RF signals reproduced from an optical disk.
Double the signal and take out the address signal Adi. Reference numeral 2 denotes an address detection circuit which extracts a sector pulse SP indicating a sector interval from the address signal Ad. The sector pulse SP is sent to three delay circuits and given a predetermined time delay to become a start pulse STP. Reference numeral 4 denotes a data generation circuit which, triggered by the input of the start pulse STP, generates recording data VDT to be recorded on the optical disc and a recording gate WGT'i indicating a recording section. Recorded data VDT
and the recording gate WGT are sent to the laser drive circuit 6,
The recording data VDT is recorded on the optical disk by intensity modulating the laser beam.

FIG. 6 shows an operation timing chart of the optical disc device shown in FIG. In FIG. 6, & is an address signal section d where the RF multiplied signal is generated by the address reproducing circuit.

b is a sector pulse SP representing a sector interval, which is obtained from the address signal section d. The sector pulse SP is given a time delay ΔTi so that recording is within the sector interval, and the data generating circuit 4 receives a start pulse STP indicated by C.
sent as. The start pulse STP serves as a trigger for the data generation circuit 4, and the recording data WDT of d, e
Record game) WGT occurs at the same time. Recorded data WD
(T and recording game) WGT is turned off within the sector interval.

Problems to be Solved by the Invention In the device, recording game) WGT and recording data V
Since the start point of DT is accurately determined by the start pulse STP, the recording start point is always at the same location within the sector, and the same location is used for repeated recordings. The nature of rewritable optical discs is that if they are repeatedly recorded in the same location, the recording marks and their surroundings will deteriorate due to thermal stress, etc., and the next time a different signal is recorded, the marks will not be recorded accurately. For example, experiments have shown that, compared to the number of repetitions of recording the same data, recording different data for each repetition improves the number of repetitions by about one digit.

In reality, even if the recorded data is different, the position of the important synchronization signal portion during reproduction is fixed, so the conventional method does not improve the number of repetitions. In view of this, the present invention randomly varies the recording start point within a sector and prevents repeated use of the same location, thereby averaging and reducing fatigue of the disk material, resulting in repeated use. An object of the present invention is to provide an optical disc device that can be used more frequently.

Means for Solving the Problems The present invention sets the recording start point in a sector of an optical disk by
This optical disc device is equipped with means for randomly changing recorded data within a range within a sector.

Effect of the Invention By changing the recording start point on the optical disc, the present invention reduces fatigue of the optical disc material due to repeated use of the same location within a sector, and increases the number of times the rewritable optical disc can be used repeatedly.

Embodiment FIG. 1 shows a partial configuration diagram of an optical disc device in a first embodiment of the present invention. FIG. 2 shows a time chart explaining the operation of the device.

First, referring to FIG. 1, parts added to the conventional example shown in FIG. 6 described above will be explained.

11 is a D-type flip-prop (hereinafter abbreviated as D-FF), which receives pulses 5PDi from the delay circuit 3;
It is latched as a data input, and the output Q is sent to the data generation circuit 4 as the start pulse STP. D-F
F11 gives a random time delay to the start pulse STP with the period of the clock CK1 which oscillates asynchronously with the data SPD. Therefore, the data generation circuit 4 simultaneously generates the recording data WDT and the recording data WGT with a random time delay of the start pulse STP, thereby varying the recording start point within the sector.

1o is a counter which divides the frequency of a clock 0KQf having a certain period to produce a clock CK1 having an appropriate period asynchronous with the data manual pulse SPD, and supplies the clock CK1 to the D-FF 11. The period of the clock CK1 is the maximum time delay given to the start pulse STP (recording data VDT, recording game)
A value is selected such that WGT falls within the range of the sector section.

Next, the operation will be explained using FIG. 2. As shown in the conventional example, a sector pulse SP of b indicating a sector section is generated from an address signal of a.

The sector pulse SP is given a predetermined time delay ΔTi by the delay circuit 3, and becomes the C pulse SPD.
Enter 11. d is the clock input CK1 of D-FF.
The FF data oscillates at a certain frequency asynchronously with the human-powered SPD. For this reason, the D-FF11 randomly latches the SPD of C as data according to the oscillation period of the clock CK1, and outputs a start pulse of e, 5TPi. In other words, the start pulse of e is 10 cycles of clock CK,
It fluctuates due to random time delays.

The start pulse STP of e enters the data generation circuit as a trigger and simultaneously generates the recording data VDT and the recording gate WGT with a random time delay. The recording data VDT and the recording gate WGT are sent to the laser drive circuit, the recording start point within the sector is changed randomly, and the recording data WDT and the recording gate WGT are shifted and recorded throughout.

As described above, according to this embodiment, the recording start point within a sector can be varied randomly by simply inserting the D-FFi in front of the data generation circuit, and the disk Material deterioration can be reduced.

FIG. 3 shows a partial configuration diagram of an optical disc device in a second embodiment of the present invention. FIG. 4 shows a time chart explaining the operation of the device.

In the second embodiment, a delay is used while the recording start point is being varied, so that the desired set value can be changed at random.

First, referring to FIG. 3, parts added to the conventional example shown in FIG. 5 described above will be explained.

2o is a counter which is controlled by a control line S to count the clock CK5 which is oscillating at a certain frequency. The outputs q and Q of the counter 2Q are randomly selected from four combinations of H'' and L''. The counter 2o is stopped by a control line S before recording starts, and holds randomly selected values of Q and Qs during recording. The outputs Q and QB of the counter 20 are connected to the input and B of the selection circuit 21.

The selection circuit 21 has a data input, 4 connected to ~DD.
Input one from the two address signals MDO to MDO3 to A and B.
randomly selected in combination with

22, 23, and 24 are analog delay circuits that provide time delays ΔT, 2ΔT, and
Gives 3ΔT.

Next, the operation will be explained using FIG. First, when the output QA of the counter 2o is QA=LIQ, =L, the selection circuit 21 selects the address signal Mdok that does not pass through the delay of the data input Dm. The operation at this time is exactly the same as in the conventional example.
A certain time delay is given by the delay circuit 3, and the start pulse C becomes 5TPo. The start pulse 5TPo of C enters the data generation circuit 4 as a trigger, and the recording game (d) WGTo and the recording data WDTo
and occur at the same timing.

Here, the output of the counter 2o is Q,=H! Qa"'
Consider the case of L. At this time, the selection circuit 21 selects the address signal d+ of e which has a time delay ΔTi when data is input. The address signal Ad of e is given a sector pulse SP1 of f by the address detection circuit 2 and given a certain time delay by the delay circuit 3, and becomes the start pulse STP of g. C start pulse S
T.P.

On the other hand, the start pulse STP of g is, therefore, the data generation circuit 4 triggered by the start pulse STP of g is Δ with respect to the recording gate WGTo of d.
Only time delayed? A recording game (with h) WGT, and recording data WIIT1 are generated.

Similarly, the output of the counter 20 is Q, =L tQ,
=H, address signal d2 of i with time delay 2ΔT is selected, and recording gate WGT2 and recording data W
DT2 is the recording gate WGT of d.

However, there is a time delay of 2ΔT.

Further, the output of the counter 2o is Q,=H.

In the case of Qs-H, the address signal d of j with a time delay of 3ΔT is selected and the recording gate WGT is selected.

and recording data WGT5 are the recording gate WGT of d.

However, there is a time delay only at 3Δ.

As described above, according to this embodiment, by providing a delay circuit and a selection circuit in the address signal line and randomly selecting the address signal using the output of the counter, the variable width of the recording start point within the sector can be changed. This can reduce fatigue of the disk material due to repeated use of the same location within a sector.

The present invention can be applied to any rewritable recording device using heat, such as a phase change type or magneto-optical type recording material.

Further, in the second embodiment, the delays 22 to 24 and the selection circuit 21 are placed before the address detection circuit 2, but the delays 22 to 24 and the selection circuit 21 are placed before the address detection circuit 2. It may be placed after the delay circuit 3 or the data generation circuit 4. I also used three delays,
Any number is acceptable as long as it is at least one.

Additionally, in the present invention, it goes without saying that the erase gate indicating the section to be erased is sufficiently longer than the recording gate and the recorded data. Preferably, the same time delay as the recording gate is applied to the erasing gate.

As described in detail, according to the present invention, an optical disc device is provided with means for randomly varying the recording start point within a sector, thereby reducing disc material by repeatedly using the same location within a sector. It is possible to reduce deterioration and increase the number of repetitions, which has great practical effects.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an optical disc device according to a first embodiment of the present invention, FIG. 2 is a timing chart for explaining the operation in the first embodiment, and FIG. 3 is a diagram of a second embodiment of the present invention. FIG. 4 is a timing chart for explaining the operation in the second embodiment, FIG. 5 is a configuration diagram of a conventional optical disk device, and FIG. 6 is a diagram of the conventional optical disk device. 5 is a timing chart for explaining the operation of the optical disc device. 1...Address regeneration circuit, 2...Address detection circuit, 3...Delay circuit, 4...
・Data generation circuit, 6... Laser drive circuit, 1
1...D-flip-flop. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 4 Figure 6

Claims (2)

[Claims] (1) An optical disc device that includes means for randomly changing the recording start point in a sector of an optical disc within a range in which recorded data falls within the sector. (2) The means for randomly changing the recording start point includes a recording data generation circuit that generates recording data using an input pulse as a trigger, and a random selection circuit that gives a random time delay to the input pulse to the recording data generation circuit. An optical disc device according to claim 1, comprising: