JPH04286768A - Optical information recording and reproducing method - Google Patents

Abstract

PURPOSE:To offer an optical information recording and reproducing method which discriminates whether data are master data or copied data and cannot reproduce the copied data. CONSTITUTION:A substituting means including a CPU 9 and a substitution re-synchronizing signal generating circuit 15 is provided on a recording system to substitute plural re-synchronous signals with a substitution signal, and a discrimination means including the CPU 9, a substitution re-synchronizing signal detecting circuit 24 and a substitution re-synchronizing signal detecting monitoring circuit 28 are provided on a reproducing system to discriminate the authenticity of the data.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording and reproducing method for distinguishing between a mask disk and a copy disk in an optical disk.

0002

[Prior Art] Optical discs have higher density recording tracks,
For reasons such as discrete partial writing and erasing, optically detectable guide tracks such as guide grooves are provided concentrically or spirally, and the recording layer formed on these guide tracks has a diameter of 1 μm or less. A focused laser beam is irradiated to create a hole or change in reflectance or transmittance to record. When attempting to record digital information whose data length is variable, the track is divided into a plurality of sectors to increase recording efficiency, and information is recorded and reproduced in units of approximately 512 bytes or 1 Kbyte. Each sector is composed of a sector index section containing track address and sector address information, and a data field section for recording and reproducing data.

On the other hand, when there are various defects, dust, scratches, etc. on the base material, recording film, protective layer, etc. of an optical disc, dropouts occur in the reproduced signal, but the recording pits and track pitch of the optical disc Since it is as small as about 1 μm, the raw error rate is very poor, and there are many long burst-like dropouts. This burst-like dropout is often caused by PLL (Pha) during playback.
se LockedLoop) and P
A bit slip phenomenon occurs in which the oscillation frequency of the LL changes and the number of self-regenerated clocks increases or decreases, and word synchronization shifts during data reproduction, causing all subsequent sector data to become errors.

[0004] For this reason, when recording data on an optical disc, a method is usually used to insert resynchronization signals into sector data at regular intervals. An example of this format is shown in FIG. Sector data consists of a synchronization pull-in signal 50 for PLL synchronization pull-in, a resynchronization signal 51 for identifying the beginning of data, and a data section 52, and one block (hereinafter referred to as a frame) is composed of m pieces. One sector consists of a frame. Data recording and reproduction is performed by detecting a sector identifier at the beginning of a sector and reading the address of the target sector. With such a configuration, even if word synchronization during playback is lost due to a bit slip phenomenon caused by a long dropout as described above, the error will be suppressed on a frame-by-frame basis by the resynchronization signal, and the error will be suppressed from the next frame onwards. , normal playback can be performed. In such a data format, when reproducing data in the target sector, a resynchronization signal is detected from the reproduction signal to activate the reproducing circuit, and the data in the target sector is reproduced. Furthermore, when a resynchronization signal cannot be detected due to a defect in the disc, the reproduction circuit is activated by detecting the resynchronization signal present in the next frame.

The operation of a reproducing method in a conventional optical information recording apparatus will be described below with reference to FIG.

Data recorded on the optical disc 1 is irradiated by a laser 2 and read out by a photodetector 3. Since the readout reproduction signal is very small, it is amplified by a preamplifier 4, and then passes through a waveform equalization circuit 5 for shaping the waveform, and then passes through a binarization reproduction circuit 6 to binarize the reproduction signal. The signal passes through and becomes a binarized reproduced signal 100. A clock 101 is generated from the binary reproduction signal 100 by the PLL circuit 8.
Extract. A clock 101 is sent to the address reproducing circuit 7. The address reproducing circuit 7 determines whether the addresses of each sector in the sector index section, for example, the CRC of the track address and the sector address, are normal, and then determines whether the target address 106 set by the CPU 9 is reached, and then sends an address detection signal. 102 to CPU
Let 9 know. The CPU 9 confirms the address detection signal 102 and outputs a demodulation control signal 104 for the target sector to the demodulation circuit 21. In the demodulation circuit 21, the PLL circuit 8 self-generates a clock 101 for the binary reproduced signal 100, and a demodulation operation is performed in accordance with this clock. In the resynchronization signal detection circuit 23, the input binary reproduction signal 10
When the bit pattern of the resynchronization signal appears among the zeros, a resynchronization detection signal is output. The demodulation timing gate signal generation circuit 26 outputs a demodulation timing gate signal in frame units according to these signals, and performs demodulation of one sector. The demodulated data is sent to the RAM control circuit 30 together with the RAM write gate signal and written into the RAM 31. Demodulated data of all frames is stored in RAM
31 and the demodulation operation for one sector is completed,
The error correction detection circuit 29 checks the demodulated data for errors, corrects any errors, generates correct data, and sends the data to the host computer 20.

Next, a bit slip detection circuit will be explained. The resynchronization detection signal and the mask gate signal for masking false resynchronization signal detection are ANDed by an AND gate 36, and the output thereof is input to the clear terminal of the counter 32. This counter 32 receives the PLL clock 101 as a clock input, and when it counts one frame's worth of reproduced clocks, the decoder 33 outputs a predicted signal to the position comparison circuit 34 . In this position comparison circuit 34,
The resynchronization signal information generation circuit detects the presence or absence of bit slip reproduction by comparing the positions of the resynchronization detection signal and the predicted signal within a window signal that has a width of ± several bits with respect to the output position of the resynchronization detection signal. At 35, resynchronization information indicating the detection state of the resynchronization signal is generated and sent to the RAM control circuit 30.

[0008] The resynchronization information is stored in a RAM, for example, during demodulation.
The data is written in the demodulated data management area No. 31, and is used in the event that an error cannot be corrected after error detection and correction, and the cause of the error is the occurrence of a bit slip. Normally, a data reproduction gate is generated from the resynchronization signal, and data is stored in a buffer memory in units of frames. However, if a resynchronization signal is not detected, for example, if the first resynchronization signal is not detected, the data following the next detected resynchronization signal will not be erroneously stored in the buffer memory area of the first frame. After confirming that the undetected frame is undetected, the buffer memory address is forced to the address where the next frame's data should be stored so that the next frame's data can be stored in the specified location. Change to (Reference: Application number Tokuhei 1-182871)

[0009]

[Problems to be Solved by the Invention] However, the above configuration has a problem in that it is not possible to distinguish between master data and replicated data.

[0010] The present invention solves the above problem, and when recording data, by omitting or replacing the resynchronization signal of an arbitrary frame, during playback, the master data or the copied data is determined based on the detection information of the resynchronization signal. The purpose of the present invention is to provide an optical information recording and reproducing method that can distinguish between genuine and false data.

[0011]

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a replacement means for replacing a plurality of resynchronization signals with different signals in the recording system, and a means for detecting the authenticity of the recording medium in the reproduction system by detecting the different signals. The apparatus includes a discriminating means for discriminating.

0012

[Operation] The present invention uses the above-described configuration to distinguish whether master data or replicated data is genuine or false.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical information recording and reproducing method according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a recording method of an optical information recording and reproducing method according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a reproducing method.

1 and 2, 1 is an optical disk, 2 is a laser, 3 is a photodetector, 4 is a preamplifier, 5 is a waveform equalization circuit, 6 is a binarization reproduction circuit, 7 is an address reproduction circuit, 8 is a PLL circuit, 9 is a CPU, 10 is a modulation circuit, 1
1 is a gate signal generation circuit, 12 is a synchronization pull-in generation circuit, 13 is a resynchronization signal generation circuit, 14 is a data generation circuit,
15 is a replacement resynchronization signal generation circuit, 16 is an AND circuit, 1
7 is a multiplex circuit, 18 is a laser drive circuit, 19
is a parity generation circuit, 20 is a host computer, 21
2 is a demodulation circuit, 22 is a shift register circuit, 23 is a resynchronization signal detection circuit, 24 is a replacement resynchronization signal detection circuit, 25 is a prediction signal generation circuit, 26 is a gate signal generation circuit, 27 is a data regeneration circuit, and 28 is a replacement circuit. A resynchronization signal detection monitor circuit, 29 an error correction circuit, 30 a RAM control circuit, 31 a RAM, 100 a binary reproduction signal, 101
1 is a clock, and 102 is an address detection signal.

The operation of the optical information recording and reproducing method having the above-described structural blocks will be explained below with reference to FIGS. 1 and 2.

Note that an optical disk 1, a laser 2, a photodetector 3
, preamplifier 4, waveform equalization circuit 5, binarization reproduction circuit 6,
Address reproduction circuit 7, PLL circuit 8, CPU 9, binary reproduction signal 100, clock 101, address detection signal 1
02 has the same configuration as the conventional example.

First, the recording operation will be explained with reference to FIG. The CPU 9 receives a control signal 1 for data recording operation.
03 to the modulation circuit 10. In the modulation circuit 10, a gate signal generation circuit 11 sends gate signals to a synchronization pull-in generation circuit 12, a resynchronization signal generation circuit 13, and a data generation circuit 14, respectively. The data generation circuit 14 receives data that has been sent from the host computer 20 and has parity added thereto by the parity generation circuit 19 . The data generated by each generation circuit is then combined by a multiplex circuit 17 and sent to a laser drive circuit 18, where the data is recorded on the optical disc 1 via the laser 2.

On the other hand, the replacement resynchronization signal generation circuit 15
A command from the PU 9 replaces the resynchronization signals of a plurality of frames with replacement resynchronization signals. If replaced, the resynchronization signal is sent from the gate signal generation circuit 11 to the AND circuit 1.
Masked by 6. In this embodiment, the output of the resynchronization signal generation circuit 13 is masked, but the gate signal of the resynchronization signal generation circuit 13 itself may be masked so that no resynchronization signal is generated.

Next, the reproduction operation will be explained with reference to FIG. The CPU 9 sends a demodulation control signal 104 to the demodulation circuit 21 for data reproduction operation. In the demodulation circuit 21, 2
The digitized reproduction signal 100 is subjected to serial-to-parallel conversion in a shift register circuit 22 according to a clock 101, and the signal is sent to a resynchronization signal detection circuit 23, a replacement resynchronization signal detection circuit 24, and a data reproduction circuit 27. Then, a prediction signal generation circuit 25 generates a prediction signal, a gate signal generation circuit 26 generates a gate signal for reproducing the data, a data reproduction circuit 27 demodulates the data, and the demodulated data is used together with a RAM write gate signal. The data is sent to the RAM control circuit 30 and written into the RAM 31. The demodulated data of all frames is written into the RAM 31, and when the demodulation operation of one sector is completed, the data is sent to the error correction circuit 29 and further sent to the host computer 20.

On the other hand, the number of replacement resynchronization signals detected by the replacement resynchronization signal detection circuit 24 is counted by the replacement resynchronization signal detection monitor circuit 28, and if the number is less than a predetermined number set in advance by the CPU 9, reproduction is performed. The gate signal generation circuit 2 immediately determines that the data is copied data.
6 and the error correction circuit 29,
The reproduction operation is stopped and no data is sent to the host computer 20.

As described above, according to this embodiment, when master data is copied and the data on the copied disk is reproduced, the detection of the replacement resynchronization signal signal is monitored, so that the data is transferred to the master disk. This makes it possible to determine the authenticity of the original or the copied disc.

However, the method of replacing the resynchronization signal with a replacement resynchronization signal when recording master data is only possible when creating a mastering disc, for example when recording application software on the disc.

Although this embodiment has been explained using an optical disk as an example, it is also possible to apply the present invention to optical cards, optical tapes, and even magnetic recording media.

[0025]

As is clear from the above embodiments, according to the present invention, when recording data, the resynchronization signal of a plurality of frames is replaced. It is possible to provide an optical information recording and reproducing method that distinguishes between original data and copied data.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a recording method of an optical information recording and reproducing method in an embodiment of the present invention.

FIG. 2 is a block diagram showing a reproduction method of an optical information recording and reproduction method in an embodiment of the present invention.

[Figure 3] Format of data field of optical disc

[Fig. 4] Block diagram showing a reproduction method of a conventional optical information recording and reproduction method.

[Explanation of symbols]

9 CPU 11 Gate signal generation circuit 15 Replacement resynchronization signal generation circuit 16 AND circuit 24 Replacement resynchronization signal detection circuit

Claims (2)

[Claims] 1. A recording/reproducing apparatus for a recording medium having a sector structure including a synchronization pull-in signal, a resynchronization signal for identifying the beginning of data, and a feed portion containing data, wherein a plurality of said resynchronization signals are provided in a recording system. 1. An optical information recording and reproducing method, comprising: a replacing means for replacing a signal with a different signal; and a discriminating means for determining authenticity of the recording medium by detecting the different signal in a reproducing system. 2. The replacing means includes means for masking the resynchronization signal, and replacement resynchronization signal generation means for replacing the resynchronization signal with a replacement resynchronization signal according to a command from a CPU, replacement resynchronization signal detection means for detecting replacement resynchronization signals; and authenticity determination means for determining that the used recording medium is false when the number of detected replacement resynchronization signals is less than or equal to a predetermined number set in the CPU. The optical information recording and reproducing method according to claim 1, comprising: