JPH027232A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent erroneous discrimination for a code from being generated in reproduction by compensating the edge travel of a reproducing signal due to the finite value of a light spot. CONSTITUTION:A quantity of correction in which the quantity of correction obtained by calculation based on a phase difference outputted from a phase difference detecting means 103 is added on the quantity of correction already stored is stored in a correction quantity integration storage means 105. The edge position of an input digital signal is corrected via an edge position correction means 106 corresponding to the above quantity of correction, and a recording carrier 108 is irradiated by a beam of light by a signal recording means 101, and a pit is recorded. In such a way, it is hard to generate the erroneous discrimination for the code in the reproduction even where short length of '0' or '1' of the input digital signal exists, and a device with high reliability can be obtained even when information is recorded in high density of the recording carrier.

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to an optical information recording/reproducing device for optically recording digital information on a record carrier such as a disk or tape. 2. Description of the Related Art In recent years, optical information recording and reproducing devices for optically recording and reproducing information from record carriers such as video discs and compact discs have been commercialized. Hereinafter, with reference to the drawings, the reproduction principle of the above-mentioned conventional optical information recording and reproduction apparatus will be explained using a compact disc as an example. FIG. 4 is a diagram showing the principle of playback of a compact disc. 40
1 is a luminous flux, 402 is an objective lens, 403 is a light spot,
404 is a bit. On a compact disc, information is recorded that is modulated into a convex structure on the disc surface called a bit 404 whose length is defined by one interval. Information is reproduced from the via) 404 using an objective lens 402 to narrow down the light beam 401 to a light spot 403 to the convergence limit.
This is done by irradiating the disc surface with light and measuring the amount of light reflected from the disc surface. When the light spot 403 is not on the bit 404, the reflected light enters the objective lens 402 again without loss and is detected as a photocurrent. However, when the light spot 403 is above the bit 404, the reflected light is spread by diffraction at the bit 404, the amount of light that re-enters the objective lens 402 is reduced, and the photocurrent is smaller than in the former case. FIG. 5 is a waveform diagram showing the relationship between this photocurrent and the bit. a is a 1°0 digital signal modulated according to information G, b is a bit recorded corresponding to the digital signal, C is a photocurrent waveform during reproduction, and d is a digital signal reproduced from the photocurrent waveform. It is. In this way, the presence or absence of focus can be detected from the reproduction signal obtained from bits or bit intervals, and the information recorded on the disc can be reproduced. (For example, MJ Wireless and Experimental Special Edition CD Digital Audio Mastering Techniques, pages 9 to 11) Problems that the invention aims to solve Because the size of the light spot takes a finite value determined by the aperture ratio of the objective lens and the wavelength of the reproduced light. As shown in FIG. 5, when the bit size becomes smaller, the photocurrent waveform of the reproduced signal does not fall completely, and the signal corresponding to the bit size is reproduced shorter than it actually is. This phenomenon also occurs when the bit interval becomes narrower, and the signal is reproduced shorter than the actual bit interval. In the case of compact discs, information is recorded and reproduced by changing the focus length and bit spacing, so errors in code discrimination during playback can occur, especially in areas where the bit length is short or the focus spacing is narrow. It had the drawback of being raw. This is not limited to cases where information is expressed by the length of the bits or the focus interval, such as on compact discs, but even when 1.0 is expressed by the presence or absence of focus, when the bit interval is narrow, the signal is reproduced narrower. This has caused problems when recording and reproducing information at high density on optical discs. In view of the above-mentioned problems, the present invention provides an optical information recording/reproducing device that can record and reproduce information at high density on an optical disc. Means for Solving the Problems In order to solve the above problems, the present invention provides an edge position correction means for correcting the edge position of an input digital signal, and a method for correcting the corrected digital signal output from the edge position correction means. a signal recording means having a function of intermittent a first beam of light to record information on a record carrier in response to a signal recording means; and a signal recording means having a function of intermittent a first beam of light to record information on a record carrier; a signal reproducing means for outputting the input digital signal; a phase difference detecting means for detecting a phase difference by comparing the input digital signal and the output of the signal reproducing means; and one edge before and after the edge of the input digital signal.
. a correction amount integral storage means for calculating a correction amount for the edge position of the input digital signal, adding the correction amount to an already stored correction amount, and newly storing the added correction amount; The means is characterized in that the edge position of the input digital signal is corrected in accordance with the correction amount output from the correction amount integral storage means. Effect of the Invention With the above-described configuration, the present invention can compensate for the shift of the edge of the reproduced signal peculiar to optical disks due to the finite value of the light spot, and it is possible to compensate for the shift of the edge of the reproduced signal, which is unique to optical disks, and makes it possible to distinguish between codes during reproduction even when recording at high density. errors can be minimized. Embodiment Hereinafter, an optical information recording/reproducing apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an optical information recording/reproducing apparatus according to an embodiment of the present invention. In FIG. 1, 101 is a signal recording means, 102
103 is a signal reproduction means, 103 is a phase difference detection means, 104 is a code discrimination means, 105 is a correction amount integral storage means, 106 is an edge position correction means, 107 is a delay circuit, and 108 is a record carrier. The operation of the optical information recording/reproducing apparatus constructed as described above will be explained with reference to FIGS. 1, 2, and 3. For example, in the case of an EFM signal, the input digital signal is T
The basic unit is composed of 1's or 0's having a length of 3T to IIT, and pits are recorded on the record carrier 108 in correspondence with the 1's or O's. First, the 1s before and after the rising or falling edge of the input digital signal.
In all cases where the length of the 0 code is zero, an initial value is input into the correction amount integral storage means 105 so that the correction amount becomes zero, and the input digital signal is corrected via the edge position correction means 106. The signal recording means 101 outputs the signal to the signal recording means 101 in response to 1 or O of the input digital signal, and records the pits on the drum body 108, and the signal reproducing means 102 reproduces the digital signal from the recorded pits. do. The signal recording means 101 may be constituted by, for example, an AO modulator or an EO modulator, and may record pits by irradiating a light beam onto the record carrier 10 when the digital signal is O. The signal reproducing means 102 is the record carrier 10
A photocurrent signal obtained by irradiating a light beam onto the photodetector 8 and receiving the reflected light by a photodetector is waveform-shaped to detect a digital signal. The output of the signal reproducing means 102 and the phase of the input digital signal are compared, the phase difference detecting means 103 detects the phase difference, and the signal before and after the rising or falling edge of the input digital signal output from the sign determining means 104 is detected. Corresponding to the length of 1.0, the correction amount calculated based on the phase difference output from the phase difference detection means 103 is added to the correction amount already stored in the correction amount integral storage means 105. The added correction amount is newly stored in the correction amount integral storage means 105. Specifically, for example, as shown in FIG.
22 and the latch circuit 223, the correction amount integral storage means 10
Shift registers 201, 202, 203, 204, and 205 that take in input with a clock synchronized with the input.
, 206, 207, 208, 209° 210 and the outputs of the shift registers 205 and 206. The already stored correction amount obtained by latching from the RAM 221 in the launch circuit 223 is added to the correction amount calculated by the calculation adding circuit 222 based on the output of the phase difference detection means 103 in response to the addition. New correction amount is stored in RAM.
Write to 221. After that, for the input digital signal inputted, the code determination means 104 determines its code structure, and according to the code structure, the input digital signal is transferred to the edge position by the correction amount stored in the correction amount integral storage means 105. Corrected via the correction means 106, and recorded i3 by the signal recording means 101 according to 1 or O of this corrected digital signal.
The focus is recorded on the carrier 108. By repeating such an operation every time an input digital signal is input, the correction amount is calculated based on the phase difference output from the phase difference detection means 103 and the correction amount already stored in the correction amount integral storage means 105. The edge position of the input digital signal is corrected via the edge position correction means 106 according to this correction amount, and the signal recording means 101 irradiates the record carrier 108 with a light beam. and record the pit. If the digital signal output from the signal reproducing means 102 is delayed compared to the input digital signal due to a slight deviation between the recording position and the reproducing position, the input digital signal is detected by the phase difference detecting means 103.
The delay circuit 107 may be inserted between the input signals. The length of the shift register may be determined according to the range of influence of the light spot on the record carrier 10B. Specifically, the edge position correction means 106 can be constructed of a multiplexer 301 and a delay circuit 302 as shown in the third figure. Select terminal 30 of multiplexer 301
3 connects the data in the RAM 221 to the latch output terminal 224 launched by the launch circuit 223 so that the delay time can be varied according to this latch output, and the signal is output according to the corrected input digital signal output from the multiplexer 301. Bits are recorded on the record carrier 108 by the recording means 101 . In order to match the timing of the select terminal and the edge timing of the input digital signal to be corrected, the output can be taken out from the shift register 206 and the output terminal 225 can be connected to the input terminal 304 of the multiplexer, as shown in FIG. . As described above, according to this embodiment, by repeating the operation of recording bits on the record carrier according to 1.0 of the corrected input digital signal, it is possible to record bits at short bits or at corners between short bits during playback. It is possible to minimize errors in code discrimination that tend to occur, and improve the reliability of the device. Effects of the Invention As described above, the present invention includes an edge position correction means for correcting the edge position of an input digital signal, and a second edge position correction means for recording information on a record carrier according to the corrected digital signal output from the edge position correction means. a signal recording means having a function of intermittent one light beam; a signal reproducing means for outputting a digital signal based on the signal recorded on the record carrier by irradiating the record carrier with a second light beam; a phase difference detection means for detecting a phase difference between a digital signal and the output of the signal reproduction means by comparing the output; a code determination means for determining the length of 1.0 before and after an edge of the input digital signal; Calculate the amount of correction of the edge position of the input digital signal based on the output of the phase difference detection means according to the lengths of 1 and 0 before and after the edge of the input digital signal output from the discrimination means, and perform the correction. The edge position correction means includes a correction amount integral storage means for adding the amount to the already stored correction amount and newly storing the added correction amount, and the edge position correction means adds the correction amount to the correction amount outputted from the correction amount integral storage means. Since the edge position of the input digital signal is corrected accordingly, errors in code discrimination are unlikely to occur during playback even when the length of 1 or 0 in the input digital signal is short, and the recording medium can be printed at high density. It is possible to provide a device with high reliability even when recording information on a computer.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an optical information recording and reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram of a code discrimination means and correction amount integral storage means, and FIG. 3 is a block diagram of an edge position correction means. The fourth leap is an explanatory diagram of a conventional optical information recording/reproducing apparatus, and FIG. 5 is a waveform diagram of the conventional optical information recording/reproducing apparatus. 101...Signal recording means, 102...
Signal reproducing means, 103... Phase difference detecting means, 1
04... Sign discrimination means, 105... Correction integral storage means, 106... Edge position correction means, 108... Record carrier. Name of agent: Patent attorney Toshio Nakao (1 person) Figure 1 Figure 3 Stomach diagram Procedural amendment 1986 30 [ ] 1988 Patent application No. 305045 Title of invention Optical information recording and reproducing device Person who makes the amendment Address related to the incident: Representative Patent Applicant: Akira Tanii, Matsushita Electric Industrial Co., Ltd., 1006 Kadoma, Kadoma City, Osaka (582) Address: 1006 Kadoma, Kadoma City, Osaka 571 Address Matsushita Electric Industrial Co., Ltd. 5 Details to be corrected Lu 1. Name of the invention Optical information recording and reproducing device 2. Claims Edge position correction means for correcting the edge position of an input digital signal, and the edge position correction a signal recording means having a function of intermittent a first beam of light for recording information on a record carrier according to a corrected digital signal outputted from the means; a signal reproducing means for outputting a digital signal based on the signal recorded on the record carrier; a phase difference detecting means for detecting a phase difference by comparing the input digital signal and the output of the signal reproducing means; a sign discriminating means for discriminating the phase and straightness of the edges of the input digital signal; and the phase difference detecting means according to the edge tracking of the input digital signal output from the sign discriminating means. and correction amount integral storage means for calculating the correction amount of the edge position of the input digital signal based on the output of the input digital signal, adding the correction amount to the already stored correction amount, and storing the added correction amount as a new value. The optical information recording and reproducing apparatus is characterized in that the edge position correction means is configured to correct the edge position of the input digital signal according to the correction amount output from the correction amount integral storage means. 3. DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an optical information recording/reproducing apparatus for optically recording digital information onto a record carrier such as a disk or tape. 2. Description of the Related Art In recent years, optical information recording and reproducing devices for optically recording and reproducing information from record carriers such as video discs and compact discs have been commercialized. Hereinafter, with reference to the drawings, the reproduction principle of the above-mentioned conventional optical information recording and reproduction apparatus will be explained using a compact disc as an example. JshiLi't Compact Disc "(S+7),
-"There is f. 501 is a luminous flux, 502 is an objective lens, 50
3- is a light spot, and 504 is a focus. On a compact disc, information is recorded that is modulated in a convex structure on the disc surface called pits 504, each having a length of 9 intervals. Reproduction of information from the optical disc 504 is performed by irradiating the disc surface with a light spot 5o3 that has narrowed down the light beam 501 to the convergence limit using the objective lens 6i02, and checking the amount of light reflected from the disc surface. When the light spot 503 is not above the pin 504, the reflected light enters the objective lens 502 again without loss and is detected as a photocurrent. However, the light spot 503 is the pit 5
When it is above 04, the reflected light is spread by diffraction at 604, and the amount of light that re-enters the objective lens 93 is reduced, making the photocurrent smaller than in the former case. FIG. 6 is a waveform diagram showing the relationship between this photocurrent and pits. - The theory is that the 1°0 digital signal modulated according to the information, (b) are the pits recorded corresponding to the digital signal, and the charging current waveform 5 (d) during playback is the same as the charging current waveform. This is a reproduced digital signal. In this way, the presence or absence of pits can be detected from the reproduction signal obtained from the pits or the intervals between the pits, and the information recorded on the disc can be reproduced. (For example, MJ Wireless and Experimental Special Edition CD Digital Audio Mastering Techniques pages 9 to 11) Problems to be Solved by the Invention Since the size of the light spot takes a finite value determined by the aperture ratio of the objective lens and the wavelength of the reproduced light, As shown in FIG. 6(C), when the size of the pit becomes smaller, the charge flow waveform of the reproduced signal does not fall completely as shown by x and y, and the signal corresponding to the size of the pit is reproduced shorter than it actually is. This phenomenon also occurs when the pit spacing becomes narrow, and the signal is reproduced shorter than the actual pit spacing. In the case of compact discs, information is recorded and reproduced by changing the length of the pits and the spacing between the pits, so errors in code discrimination during playback can occur, especially in areas where the pit length is short or the pit spacing is narrow. The disadvantage is that it is easy to occur. This is not limited to cases where information is expressed by the length of the pits or the distance between the focus points, such as on compact discs, but even when 1.0 is expressed by the presence or absence of pits, when the pit intervals are narrow, the signal is reproduced more narrowly. However, this has been a problem when recording and reproducing information at high density on optical discs. In view of the above-mentioned problems, the present invention provides an optical information recording and reproducing device that can record and reproduce information at high density on an optical disc. Means for Solving the Problems In order to solve the above problems, the present invention provides an edge position correction means for correcting the edge position of an input digital signal, and an edge position correction means for correcting the edge position of an input digital signal, and a digital signal output from the edge position correction means according to the corrected digital signal. A signal recording means having a function of intermittent a first beam of light for recording information on a record carrier, and outputting a digital signal based on the signal recorded on the record carrier by irradiating the record carrier with a second beam of light. a signal reproducing means for detecting the input digital signal; a phase difference detecting means for detecting a phase difference between the input digital signal and the output of the signal reproducing means; and a phase difference detection means for determining the length before and after the edge of the input digital signal. a sign discriminating means; and a correction amount of the edge position of the input digital signal is calculated based on the output of the phase difference detecting means according to the length before and after the edge of the input digital signal output from the sign discriminating means. A correction amount integral storage means is provided for adding the correction amount to an already stored correction amount and newly storing the added correction amount, and the edge position correction means is outputted from the correction amount integral storage means. The present invention is characterized in that the edge position of the input digital signal is corrected in accordance with the amount of correction. Effect: With the above-described configuration, the present invention can compensate for the edge movement of the reproduced signal peculiar to optical disks caused by the light spot having a finite value, and even when recorded at high density, code discrimination during reproduction is possible. Errors can be minimized. Embodiment Hereinafter, an optical information recording/reproducing apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an optical information recording/reproducing apparatus according to an embodiment of the present invention. In FIG. 1, 1o1 is a signal recording means, 10
2 is a signal reproducing means, 103 is a phase difference detecting means, 104 is a sign discriminating means, 105 is a correction amount integral storage means, 106 is an edge position correcting means, 107 is a delay circuit, and 108 is a recording carrier. The operation of the optical information recording/reproducing apparatus configured as described above will be explained with reference to FIGS. 1, 2, and 3. The input digital signal may be, for example, a
or 0, and pits are recorded on the record carrier 108 in correspondence with the 1 or 0. First, for any case where the length of the 1 and 0 symbols before and after the rising edge or falling edge of the input digital signal is
Correction amount integral storage means 105 so that the correction amount becomes zero.
The initial value is output to the signal recording means 101, the signal recording means 101 records a pit on the record carrier 108 according to 1 or 0 of the input digital signal, and the signal reproducing means 102 records a digital signal from the recorded pit. Play the signal. The signal recording means 101 records the light beam on the recording carrier 1o8.
All you have to do is record the pits by irradiating the area. Signal reproducing means 10
2 detects a digital signal by irradiating a light beam onto the record carrier 108 and receiving the reflected light by a photodetector, shaping the waveform of a photocurrent signal obtained. This signal reproducing means 1
02 and the phase of the input digital signal are compared, and the phase difference detection means 103 detects the phase difference. At this time,
1. before and after the rising edge 9 or falling edge 9 of the input digital signal output from the sign discrimination means 104.
Corresponding to the length of 0, the correction amount obtained by calculating based on the phase difference at the edge outputted by the phase difference detection means 103 is the correction amount already stored in the correction amount integral storage means 105. , and the added correction amount is newly recorded in the correction amount integral memory 81o5. Correspondingly, the already stored correction amount obtained by latching from the RAM 221 with the latch circuit 223 is added to the correction amount calculated by the calculation adding circuit 222 based on the output of the phase difference detection means 103. Newly RA the corrected amount
Write to M221. For the input digital/l' signal input after that,
The code determination means 104 determines the code structure, and the input digital signal is corrected by the correction amount stored in the correction M-integral storage means 105 according to the code structure via the edge position correction means 106. Bits are recorded on the record carrier 108 by the signal recording means 101 according to 1 or 0 of this corrected digital signal. By repeating this operation every time an input digital signal is input, the phase difference output from the phase difference detection means 103 is added to the correction amount already stored in the correction amount integral storage means 106. The correction amount obtained by adding the correction amount calculated based on the above-mentioned information is stored. The edge position of the input digital signal is corrected via the edge position correction means 106 according to this correction amount, and the signal recording means 101 irradiates the recording medium 108 with a light beam to record pits. (e) is phase-compared, and the digital output from the signal reproducing means 102 is compared to the input digital signal when the position of recording on the third record carrier and the position of reproduction are slightly different. If the signal is delayed, the delay circuit 107 may be inserted while the input digital signal is input to the phase difference detection means 103. The length of the shift register may be determined according to the range of influence of the light spot on the record carrier 108. 402 is a delay circuit, 403 is a select terminal 404 is an input terminal, and 405 is an output terminal. As described above, according to this embodiment, by repeating the operation of recording pits on the record carrier according to 1.0 of the corrected input digital signal, it is possible to record pits at short pits or at short focus intervals during playback. Errors in code discrimination that tend to occur can be minimized, and the reliability of the device can be improved. Effects of the Invention As described above, the present invention includes an edge position correction means for correcting the edge position of an input digital signal, and a second edge position correction means for recording information on a record carrier according to the corrected digital signal output from the edge position correction means. a signal recording means having a function of intermittent one light beam; a signal reproducing means for outputting a digital signal based on the signal recorded on the record carrier by irradiating the record carrier with a second light beam; a phase difference detection means for detecting a phase difference between the digital signal and the output of the signal reproducing means by comparing the digital signal with the output of the signal reproduction means; a code discrimination means for discriminating the length before and after the edge of the input digital signal; The amount of correction of the edge position of the input digital signal is calculated based on the output of the phase difference detection means according to the length before and after the edge of the input digital signal outputted from the discrimination means, and the amount of correction is already stored. The edge position correction means includes a correction amount integral storage means for adding the correction amount to the correction amount and newly storing the added correction amount, and the edge position correction means adjusts the input digital value according to the correction amount output from the correction amount integral storage means. It is configured to correct the edge position of the signal, so that the 1 or 0 of the input digital signal
Even when the length of the code is short, code discrimination errors are unlikely to occur during reproduction, and the device can be highly reliable even when recording information on a record carrier at high density.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an optical information recording/reproducing apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram of a code discriminating means and a complementary signal recording means. 102...
Signal reproducing means, 103... Phase difference detecting means, 1
04... Sign discrimination means, 105... Correction amount integral storage means, 106... Edge position correction means, 108... Record carrier. Name of agent: Patent attorney Shigetaka Awano and one other person

Claims (1)

[Claims] An edge position correction means for correcting an edge position of an input digital signal, and a signal having a function of intermittent a first light beam for recording information on a record carrier in accordance with the corrected digital signal output from the edge position correction means. a recording means; a signal reproducing means for outputting a digital signal based on a signal recorded on the record carrier by irradiating the record carrier with a second light beam; phase difference detection means for detecting the phase difference by comparison; sign discrimination means for determining the lengths of 1 and 0 before and after the edge of the input digital signal;
A correction amount for the edge position of the input digital signal is calculated based on the output of the phase difference detection means according to the lengths of 1 and 0 before and after the edge of the input digital signal outputted from the sign determination means. and a correction amount integral storage means for adding the correction amount to an already stored correction amount and newly storing the added correction amount, and the edge position correction means is outputted from the correction amount integral storage means. An optical information recording/reproducing apparatus characterized in that the apparatus is configured to correct an edge position of the input digital signal according to a correction amount.