JPH0341621A - Optical recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent a recording pit from forming in the same place by provid ing a recording data generating circuit and a data reproducing circuit capable of reproducing a data at a frame mark regarded upon detection of any one of different frame marks in pattern. CONSTITUTION:The frame mark pattern is changed for each recording by providing the recording data generating circuit with plural frome mork generat ing circuits 12-14 for generating their respective different frame mark patterns and a selector 17 for selecting one pattern at random from plural frame mark patterns A-C. Moreover, the data reproducing circuit is provided with plural frame mark detecting circuits 21-23 for detecting plural frame mark patterns A-C respectively. Consequently, the frame marks can accurately be detected, and their data can correctly be reproduced. By this method, the recording pit can be prevented from always forming in the same place, and the fatigue of a disk material is alleviated, and also the number of recording and reproducing repetitions can be promoted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an optical recording/reproducing device, and specifically, it irradiates an optical disk with a laser beam with a diameter of approximately 1 micron to record and reproduce signals with high density. - This invention relates to a rewritable optical recording and reproducing device that can repeatedly record and reproduce signals by erasing previously recorded signals by laser irradiation.

2. Description of the Related Art An example of the above-mentioned conventional optical recording/reproducing device will be described below with reference to the drawings.

FIG. 5 shows the countries in which conventional optical recording and reproducing devices are made up.

Light from a light source 2 such as a semiconductor laser is transmitted through a lens or the like.
The light is narrowed down to a minute light spot of about 1 micron and irradiated onto the optical disc 1. The reflected light from the optical disc l is detected by optical detection i! The signal is guided to S3, and a reproduced signal RF is obtained. During reproduction, the reproduction signal RF is input to the data reproduction circuit 6,
The data is played back.

During recording, the recording gate WG is output from the recording data generation circuit 4.
T and recording data WDT are input to the laser drive circuit 5, which modulates the intensity of the laser beam and outputs the recording data onto the optical disc 1.
recorded in

FIG. 6 is a block diagram of the recording data generation circuit 4, and FIG.
The figure shows the operation timing chart. The operation during recording will be explained using FIG. 6.

The reproduced signal RF is input to the address reproducing circuit 7, the address signal Ad (FIG. 7(a)) is taken out, and the address detecting circuit 8 detects a sector pulse SP indicating the sector interval from the address signal Ad (FIG. 7(a)). Take out (b)). The sector pulse SP is sent to the delay circuit 9 and given a certain predetermined time delay T to become a start pulse 5TP (FIG. 7(C)). The start pulse STP is sent to the timing generation circuit 10. The timing generation circuit 10 generates a recording gate WGT (FIG. 7(d)) indicating a recording period from the start pulse STP, and also sends select signals 5LTI and 5LT2 to the selector 28.
(Send Figure 7 (el, (f)).

The selector 28 receives the select signals 5LTI, 5L.
According to T2, the modulation circuit 11. Frame mark generation circuit 27. An operation command signal (ACT
l, ACT2. Send ACT3).

The synchronous data generation circuit 16 receives the operation command signal AC.
It operates when T1 (see FIG. 7) is "11" and sends a synchronizing signal 5YNC to the selector 28.

The frame mark generation circuit 27 operates when the operation command signal ACT2 (FIG. 7(h)) is "Ho" and sends a fixed pattern frame mark FM to the selector 28.

The modulation circuit 11 operates when the operation command (No. 3 ACT3 (Fig. 7 (1)) is "H", and modulation data V
DT is sent to the selector 28.

Then, the selector 28 configures recording data WDT (FIG. 7(j)) using the sent signals.

Here, the specific operation of the selector 28 with respect to the select signals 5LTI, SL, and T2 will be described below.

(1) When SLTI is "H" and 5LT2 is ''L'', the selector 28 sets the operation command signal ACTI ((80) in FIG. 7) sent to the synchronous data generation circuit 16 to ``H'' to generate the synchronous data. The circuit 16 is operated and the synchronizing signal 5YNC is used as recording data VDT (FIG. 7(j)).

(2) When SLTI is ``L'' and 5LT2 is H', the selector 28 sets the operation command signal ACT2 (FIG. 7(h)) to be sent to the frame mark generation circuit 27 to H'', and the frame mark generation circuit 27, the frame mark FM, which is a fixed pattern, is recorded as the recording data WDT (7th
Figure (j)).

(3) When SLTI is “Ho” and 5LT2 is “H”, the selector 28 sends the operation command signal ACT3 to the modulation circuit 11.
(Fig. 7(i)) is set to "'1", and the modulation circuit 1
1, the modulation data VD pre-recorded data WDT (
Figure 7(j)).

Finally, the recording gate WGT from the timing generation port mto and the recording data WDT from the selector 28 are as follows:
It is sent to the laser drive circuit 5 and recorded.

FIG. 8 shows a block diagram of the data reproducing circuit 6, and FIG. 9 shows an operation timing chart. The operation during reproduction will be explained using FIG. 8. Reproduction signal RF (Figure 9(a))
is binarized by the binarization circuit 19, and the PLL circuit 20
The signal is also supplied to the frame mark detection circuit 29 and demodulation circuit 24. Frame mark detection circuit 29
is the frame mark pattern in the reproduced signal RF.
1 BLL, frame mark detection signal FMD (9th
Figure (b)) is output. The frame mark detection signal F
MD is input to the demodulation timing generation circuit 26, and in RF, a data gate signal DOT indicating the position of data is input.
(FIG. 9(C)) is output. The demodulation circuit 24 extracts, from the reproduced signal RF and the data gate signal DGT,
The data is demodulated and demodulated data is output.

Problems to be Solved by the Invention However, in the above configuration, the frame mark pattern is always a fixed pattern, and the laser is always irradiated to the same position on the disk to record recording bits. Therefore, the same location is always used to form recording bits in repeated recordings. Due to the nature of rewritable optical discs, if recording bits are repeatedly formed in the same location over and over again, the recording bits and their surroundings will deteriorate faster than usual due to thermal stress, making accurate recording impossible. Experiments have shown that the number of times that recording can be repeated is an order of magnitude worse than the number of times that data with a different pattern can be repeated each time.

Therefore, there was a problem in that deterioration started at a relatively early stage from the frame mark of the fixed pattern, making the data unreadable.

In view of this, the present invention prevents the recording focus from being formed at the same location by recording a frame mark with a different pattern each time, thereby reducing fatigue of the material and increasing the number of repetitions of recording and reproduction. It is an object.

Means for Solving the Problems In order to solve the above problems, the optical recording/reproducing device W of the present invention includes:
A recorded data generation circuit that generates recorded data with a different frame mark pattern for each recording, and a data reproducing circuit that can reproduce data by regarding it as a frame mark if any of the different frame mark patterns is detected. , has been prepared.

Effects of the present invention With the above-described configuration, the present invention reduces material fatigue by preventing frame marks of the same pattern from being recorded each time, that is, by preventing recording bits from always being formed at the same location. You can improve the number of repetitions.

Embodiment Hereinafter, an optical recording/reproducing apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of a recording data generation circuit of an optical recording/reproducing apparatus according to the present invention. Components in FIG. 1 that are the same as those in FIG. 6 are given the same numbers. FIG. 2 shows an operation timing chart of the recording data generation circuit of FIG. 1.

Further, FIG. 3 shows an embodiment of the data reproducing circuit of the optical recording/reproducing apparatus of the present invention. In FIG. 3, the same parts as in FIG. 8 are given the same numbers. FIG. 4 shows an operation timing chart of the data reproducing circuit of FIG. 3.

First, the operation of the recording data generation circuit of the optical recording/reproducing apparatus of the present invention will be explained using FIG.

The reproduced signal RF is input to the address reproducing circuit 7, the address signal Ad (FIG. 2(a)) is taken out, and the address detecting circuit 8 generates a sector pulse SP indicating the sector interval from the address signal Ad (FIG. 2(a)). (b)], the sector pulse SP is sent to the delay circuit 9 and is given a certain predetermined time delay T to extract the start pulse STP (
Figure 2 (C)). The start pulse STP is sent to the timing generation circuit 10. The timing generating circuit IO generates a recording game) WGT (FIG. 2(d)) indicating a recording section from the start pulse STP, and also sends select signals 5LTI, 5L to the selector B08).
Send T2 (Fig. 2(e), (f)).

The selector BOB) outputs the select signal SLT l
According to 5LT2, modulation circuit II, select Af171
Operation command signal G1CTIAC to synchronous data generation circuit 16
T2. Send ACT3).

The synchronous data generation circuit 16 receives the operation command signal AC.
It operates when TI (Figure 2 (dark)) is H'' and sends a synchronizing signal 5YNC to the selector B08.

The selector A07) outputs the operation command signal ACT2(
Frame mark A generation circuit 12, frame mark B generation circuit 13, which operates when 01)) in FIG. 2 is H'' and generates frame marks of different patterns.
Three frame marks (FMA, FMB) from the frame mark C generation circuit 14.

FMC), the operation command signal ACT2 (second
A frame mark FM is selected at random according to the random number from the random number generation circuit 15 when the signal in FIG.

The modulation circuit 11 operates when the operation command signal ACT 3 (FIG. 2(i)) is "H" and modulates the modulation data V.
DT to the selector Boil).

Then, the selector Bf18) composes recording data WDT (FIG. 2(j)) using the sent signal.

Here, the specific operation of the selector BO31 with respect to the selector signals 5LTI and 5LT2 will be described below.

(1) When SLTI is “H” and 5LT2 is “L”, the selector B08) sets the operation command signal ACTI (FIG. 2 (8)) sent to the synchronization data generation circuit 16 to “H” to The data generation circuit 16 is operated and the synchronization signal 5YN is generated.
Let C be recording data WDT (FIG. 2(j)).

(2) When SLTI is "L" and 5LT2 is 'H',
The selector B08) sets the operation command signal ACT2 (FIG. 2 (b)) sent to the selector A07) to °゛H'', operates the selector AO7), and sets the frame mark FM to the recording data WDT (FIG. 2 (b)). j)).

(3) When SLTI is “H” and 5LT2 is “H”, the selector B side sends the operation command signal ACT to the modulation circuit 11.
3 (FIG. 2(i)) is set to H", and the modulation circuit 11
is operated to obtain modulated data VD pre-recorded data WDT (FIG. 2(j)).

Finally, the recording data WD from the recording gate WGT from the timing generation circuit 10 and the recording data WD from the selector Bolt)
T is sent to a laser drive circuit and recorded.

Here, as already mentioned, the frame mark FM included in the recording data WDT (FIG. 2 (j)) is selected by the selector 807) into three different patterns: FMAFMB,
Since the frame marks are randomly selected from the FMC, the probability that the same pattern of frame marks will be recorded every time is smaller than in the past. Therefore, the probability that a recording focus will be formed at the same location on the optical disk is reduced, material fatigue is reduced, and the number of repetitions of recording and reproduction can be increased.

Note that here, there are three types of frame mark patterns, but if there are two or more types, the probability that the same pattern of frame marks will be recorded each time will be smaller than in the past, so the number of repetitions of recording and playback will be reduced. It is possible to improve

Of course, the more types of frame mark patterns there are, the more
The improvement in the number of repetitions is significant.

Next, the operation of the data reproducing circuit of the optical recording/reproducing apparatus of the present invention will be explained using FIG.

The reproduced signal RF (FIG. 4(a)) is generated by the 2(+! conversion circuit 19
The signal is binarized and the PLL circuit 20 is operated.

Also, the frame mark A detection circuit 21. Frame mark B detection circuit 22. It is also supplied to the frame mark C detection circuit 23 and demodulation circuit 24. Frame mark A detection circuit 2
1 detects the frame mark A (FMA) among the frame marks in the reproduced signal RFO, and
A detection signal FMAD (FIG. 4(b)) is output. Similarly, the frame mark B detection circuit 22 detects the frame mark B
(FMB), and the frame mark C detection circuit 23 detects frame mark C (FMC), respectively.
Frame mark B detection signal FMBD (Fig. 4 FC>)
.

A frame mark C detection signal FMCD (FIG. 4(d)) is output. These detection signals FMAD and FMBD.

FMCD is sent to the OR circuit 25, and the O of the three signals is
R, the frame mark detection signal FMD (Fig. 4(e)
)) is created.

The frame mark detection signal FMD is input to the demodulation timing generation circuit 26, and in the reproduced signal RF, a data gate signal DGT (FIG. 4(r)) indicating the data position is generated.
) is output. The demodulation circuit 24 demodulates data from the reproduction signal RF and the data gate signal DGT, outputs demodulated data, and reproduces the data.

As described above, according to this embodiment, different frame mark patterns are generated in the recording data generation circuit. By including a plurality of frame mark generation circuits and a selector that randomly selects one pattern from the plurality of frame mark patterns, the frame mark pattern can be changed for each recording and recorded at the same location on the optical disk. The formation of pits can be prevented, fatigue of the disk material can be reduced, and the number of repetitions can be increased.

Furthermore, by providing the data reproducing circuit with a plurality of frame mark detection circuits that respectively detect patterns of the plurality of frame marks, frame marks can be detected correctly and data can be correctly reproduced.

Effects of the Invention As described above, the present invention provides a recording data generation circuit that includes a plurality of frame mark generation circuits that generate different frame mark patterns, and a selector that randomly selects one pattern from the plurality of frame mark patterns. By having a data reproducing circuit including a circuit and a plurality of frame mark detection circuits each detecting the patterns of the plurality of frame marks, it is possible to record frame marks of the same pattern every recording, that is, always at the same location. It is possible to prevent the formation of a recording focus on the disc, reduce fatigue of the disc material, and increase the number of repetitions of recording and reproduction.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a recorded data generating circuit of an optical recording/reproducing apparatus according to a first embodiment of the present invention, FIG. 2 is an operation timing chart of the recorded data generating circuit of FIG. 1, and FIG. A block diagram of the data reproducing circuit of the optical recording/reproducing apparatus in the first embodiment, FIG. 4 is an operation timing chart of the data reproducing circuit of FIG. 3, FIG. The figure is a block diagram of a recorded data generation circuit of a conventional optical recording and reproducing device, FIG. 7 is an operation timing chart of the recorded data generating circuit of FIG. 6, and FIG. 8 is a block diagram of a data reproducing circuit of a conventional optical recording and reproducing device. 9 is an operation timing chart of the data reproducing circuit of FIG. 8. DESCRIPTION OF SYMBOLS 1... Optical disk, 2... Semiconductor laser, 12... Frame mark A generation circuit, 13
...Frame mark B generation circuit, 14...
... Frame mark C generation circuit, 21 ... Frame mark A detection circuit, 22 ... Frame mark B detection circuit, 23 ... Frame mark C detection circuit.

Claims (3)

[Claims] (1) A recorded data generation circuit that generates recorded data with a different frame mark pattern for each recording, and a data reproduction circuit that can reproduce data by regarding it as a frame mark if any one of the plurality of different frame mark patterns is detected. An optical recording/reproducing device characterized by comprising a circuit. (2) The recording data generation circuit randomly selects one pattern from the plurality of frame mark generation circuits that generate frame marks in different patterns, and the plurality of frame mark patterns output from the plurality of frame mark generation circuits. The optical recording and reproducing apparatus according to claim 1, further comprising a selector. (3) The optical recording and reproducing apparatus according to claim 1, wherein the data reproducing circuit includes a plurality of frame mark detection circuits that respectively detect the plurality of frame mark patterns.