JP2568528B2 - Signal recording / reproducing device - Google Patents

Description

The present invention relates to an audio recording medium called a compact disk, a video recording medium called a laser disk or a video disk, and a recording medium for an information processing device such as a computer called an optical disk file. The present invention relates to a signal recording / reproducing apparatus for avoiding the influence of a defect of a recording medium when reproducing a signal.

Conventional technology Optical discs such as compact discs have pits that represent signal information, but they do not have guide grooves like conventional analog records, so in order to reproduce signals, control differs from that for analog records. Must be applied. That is, in order to pick up information held in the recording medium, control called focus servo for focusing laser light on pits and control called tracking servo for correctly tracing a row of pits are necessary.

These two controls are based on a signal called a tracking error signal and a control signal called a focus error signal, which are created by condensing laser light incident on an optical disc as a recording medium on light reflected from the optical disc surface. Done in Optical discs, which are recording media, are susceptible to defects such as defects that occur during the manufacturing process and scratches that occur during use.These defects cause the laser light incident on the optical disk to not be reflected correctly on the optical disk surface. I will. If these defects are unacceptably large, the tracking error signal and the focus error signal are greatly disturbed, so that pits on the optical disk cannot be read correctly, and reproduction signals such as music are interrupted or large noise occurs. Will be done.

In order to solve the above inconvenience, the following recording signal reproducing apparatus has been conventionally known. The description is given below with reference to the drawings.

FIG. 5 is a block diagram showing the overall configuration of a conventional recording signal reproducing apparatus. 1 is a recording medium, 2 is a reproducing means, 3 is a detecting means, and 4 is a control means. The recording medium 1 is an audio recording medium called a compact disk, a video recording medium called a laser disk or a video disk, or a recording medium for an information processing device such as a computer called an optical disk file. The reproducing means 2 is a means for driving the recording medium 1 to reproduce information contained in the recording medium 1. When a compact disc is used as the recording medium 1, an output such as a music signal can be obtained. The detection means 3 does not externally output a noise mixed in an output signal such as a tracking error signal or a focus error signal obtained from the reproduction means 2 or a music signal or the like of a recording / reproducing apparatus caused by the occurrence of a defect of the recording medium 1. The detection of the occurrence of an error detection signal such as the muting signal described above. If the control means 4 detects the occurrence of a defect of the recording medium 1 by the output of the detection means 3, the control means 4 operates the control system of the portion for driving the recording medium 1 of the reproduction means 2 to impair the information of the recording medium as much as possible. It works to play without.

Problems to be Solved by the Invention However, according to such a conventional method, the effect of the occurrence of the defect after the occurrence of the defect of the recording medium 1 is reduced to a small extent. There is a limit, and it is impossible to sufficiently cope with the defect of the recording medium 1 unless it is very small. Depending on the type and size of the defect of the recording medium 1, noise or the like is mixed in an output signal such as a music signal of the recording / reproducing apparatus. There is a problem of doing it.

In view of the above problems, the present invention, once the occurrence of a defect having a recording medium is detected, storing information necessary to avoid the influence of the defect having the recording medium such as the position where the defect occurs, When the same recording medium is reproduced next time, the influence of the defect can be avoided by controlling the reproducing means based on the stored information before the defective portion of the recording medium is reproduced. It is another object of the present invention to provide a signal recording / reproducing apparatus capable of reproducing information on a recording medium without error.

In order to solve the above problems, the signal recording and reproducing apparatus of the present invention includes a reproducing unit that reproduces a recording medium on which a signal is recorded, a recording medium recognizing unit that individually recognizes the recording medium,
Position detection means for detecting the current signal reproduction position of the recording medium, detection means for detecting a defect of the recording medium during reproduction of the recording medium, control means for controlling the reproduction means, output and control means of the reproduction means A defect detecting means for detecting information relating to a defect of the recording medium while reproducing the recording medium by the output of the recording medium; an output of the recording medium recognizing means, an output of the position detecting means, an output of the detecting means, and an output of the defect detecting means. Generation storage means for recording information for individually identifying a recording medium, a defect occurrence position of the recording medium, and information relating to a defect of the recording medium; output of the recording medium recognition means, output of the generation storage means, and position detection means; The output is used to predict the location of a defect in the recording medium during reproduction of the recording medium, to predict the location of the defect in the recording medium, and to measure the effect of the defect in the recording medium. A predicting means for predicting a control amount of the control means necessary for performing the operation, and a control amount of the control means being changed from immediately before a defect occurrence position of the recording medium based on the output of the predicting means during reproduction of the recording medium. And means for avoiding the influence of defects of the recording medium by controlling the reproducing means.

In the signal recording / reproducing apparatus of the present invention, the recording medium recognizing means and the position detecting means are coupled to the output of the reproducing means, and the recording medium is individually recognized by the recording medium recognizing means and the position detecting means. Of the current signal reproduction position is detected. The defect detection means is coupled to the output of the reproduction means and the output of the control means,
Information about the type and size of a defect included in the recording medium is detected. The occurrence storage means is coupled to the output of the recording medium recognition means, the output of the position detection means, the output of the detection means, and the output of the defect detection means, and has information for individually recognizing the recording medium, a defect occurrence position, and the storage medium. Information on the type and size of the defect is stored. The predicting means is coupled to the output of the recording medium recognizing means, the output of the position detecting means, and the output of the generation storage means, in order to avoid the occurrence position of the defect of the recording medium and the influence of the defect during reproduction of the recording medium. The type of control amount of the control means for controlling the reproducing means and the required size are predicted.
The avoiding means is combined with the output of the predicting means to control the reproducing means while reproducing the recording medium by changing the type and size of the control amount of the control means immediately before the position where the defect of the recording medium has occurred. Thus, the information of the recording medium can be reproduced without error by avoiding the influence of the defect of the recording medium.

Therefore, once the occurrence of a defect in the recording medium is detected, the identification code of the recording medium having the defect, the position where the defect has occurred in the recording medium, and information necessary to avoid the influence of the defect are stored. In the case where the same recording medium is reproduced next time, before reproducing the defect occurrence position of the recording medium, the reproducing means is controlled based on the stored information to thereby reproduce the defect. It is possible to realize a signal recording / reproducing apparatus capable of reproducing information contained in a recording medium without error while avoiding the influence.

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

FIG. 1 is a block diagram showing the overall configuration of an embodiment of a recording signal reproducing apparatus according to the present invention.

Reference numeral 1 denotes a recording medium such as an audio recording medium called a compact disk, a video recording medium called a laser disk or a video disk, and a recording medium for an information processing device such as a computer called an optical disk file. Reference numeral 2 denotes a reproducing unit for driving the recording medium 1 to reproduce information contained in the recording medium 1. When a compact disk is used as the recording medium 1, the compact disk is rotated to irradiate pits on the surface of the compact disk with laser light. After receiving the reflected light, the information contained in the pits on the surface of the compact disc is read, and if a reading error is detected by checking a correction code or the like, a signal such as a music signal is output to an external device through signal processing such as correcting the error. In addition, an output of an information signal called a subcode including a recording content information and a time code which can be used as a recognition code of the recording medium of the recording medium 1 and an error for performing a correction if a reading error is detected by checking a correction code and the like. The output of the detection signal, the recording medium 1 is rotated, and the pits on the surface of the recording medium 1 are irradiated with laser light. A tracking error signal for reading the information possessed by the pit of the received and the recording medium 1 surface reflected light, and outputs a control signal such as a focus error signal. Reference numeral 3 denotes an output signal such as a tracking error signal, a focus error signal, or the like obtained from reflected light from the recording medium 1 obtained from the reproducing unit 2 or a music signal or the like of a recording / reproducing apparatus caused by a defect of the recording medium 1. This is detection means for detecting occurrence of an error detection signal such as a muting signal for preventing the mixed noise from being output to the outside. Reference numeral 4 denotes control means for operating a control system of a portion for driving the recording medium 1 so as to read out information contained in pits on the surface of the recording medium 1 as little as possible. Reference numeral 5 denotes a recording medium recognizing unit that reads out recording content information that can be used as a recognition code of the recording medium 1 from the subcode signal obtained from the reproducing unit 2 and individually recognizes the recording medium 1. 6 is reproduction means 2
This is a position detecting means for reading the time code of the recording medium 1 from the obtained subcode signal and detecting the current signal reproduction position of the recording medium 1. Reference numeral 10 denotes a basis of an output signal such as a music signal obtained by receiving reflected light from the recording medium 1 obtained from the reproducing means 2 with a photodiode or the like.
The type of the defect of the recording medium 1 based on the RF signal, the tracking error signal and the focus error signal which are the control signals of the control system of the reproducing means 2, and the information on the type and magnitude of the control amount output from the control means 4 And a defect detecting means for detecting information on the size and the like. Reference numeral 7 denotes recording content information which can be used as a recognition code of the recording medium 1 output by the recording medium recognizing means 5, information on detection of occurrence of an error signal output by the detecting means 3, and recording output by the position detecting means 6. This is a generation storage unit that stores information on the detection of the current signal reproduction position on the medium 1 and information on the type and size of the defect of the recording medium 1 output from the defect detection unit 10. Reference numeral 8 denotes the recording medium 1 based on the output of the recording medium recognition means 5, the output of the position detection means 6, and the output of the generation storage means 7.
Is a prediction means for predicting the type and size of the control amount of the control means 4 necessary for avoiding the occurrence position of the defect of the recording medium 1 and the influence of the defect during reproduction. Reference numeral 9 denotes the recording medium 1 by controlling the reproducing means 2 by changing the control amount of the control means 4 from immediately before the defect occurrence position of the recording medium 1 based on the output of the predicting means 8 while reproducing the recording medium 1. This is avoidance means for avoiding the influence of the defects of the above.

The operation of the signal recording / reproducing apparatus configured as described above will be described with reference to FIGS.

FIG. 2 is a block diagram showing a specific configuration of an embodiment of the present invention. The functions of the above-mentioned detecting means, recording medium recognizing means, position detecting means, occurrence storing means, predicting means, avoiding means and defect detecting means are provided by a microcomputer. This is realized in 11. FIG. 3 is a flowchart showing a main part of the processing operation of the microcomputer according to the embodiment of the present invention.

If the recording medium 1 is mounted on the signal recording / reproducing apparatus of this embodiment and necessary processing for reproduction is performed, in step 20,
From the sub-code input to the microcomputer 11 from the reproducing means 2, a recognition code created from the recorded content information or the like of the recording medium 1 is determined and read, and the recognition code of the recording medium 1 is stored in the microcomputer 11 in step 21. Then, it is determined whether or not the recording medium is a recording medium in which a reproduction error has occurred previously during reproduction by comparing with the recognized recognition code. If the recording medium 1 reproduced for the first time by the signal recording / reproducing apparatus of the present embodiment is used, the process proceeds to step 22, where an error detection signal input from the reproducing means 2 to the micro computer 11 is read, and step 23 is performed. And checks an error detection signal such as a correction code to determine whether or not a reproduction error has occurred. If a reproduction error has occurred, since the recording medium 1 has a defect such as a scratch, the time code is determined and read from the subcode input to the microcomputer 11 from the reproduction means 2 in step 24. In step 25, the recording medium 1 is stored by storing the time code.
The location of a defect such as a scratch is stored. Then step 26
Then, the magnitude of a signal such as an RF signal, a tracking error signal, a focus error signal, and the like obtained by receiving reflected light from the recording medium 1 input to the microcomputer 11 from the reproducing means 2 and a change with time thereof are obtained. In addition to reading the progress, the control system 4 reads control amounts of the control system of the reproducing unit 2 such as tracking gain, focus gain, tracking offset, and focus offset which are input to the microcomputer 11 from the control unit 4, and reads the recording medium 1 from these information. In step 27, information on the type and size of the defect is detected and stored. Then step 28
Then, the recognition code of the recording medium 1 created from the recording content information of the recording medium 1 read in step 20 is stored,
The fact that the recording medium has caused a reproduction error during the reproduction is registered in the storage element of the microcomputer 11. Here, the recognition code to be registered in the storage element of the microcomputer 11 does not need to be the recording content information itself of the recording medium 1 read in step 20, and it is better to use the information after shortening it. The required amount of is small.

Next, in step 35, it is determined whether or not the reproduction of the recording medium 1 is completed. If not, the process returns to step 21, and if the reproduction is completed, a command is issued to the control means 4 to stop the recording medium 1 in step 36. Output.

Here, a fourth method for detecting information on the type and size of a defect such as a scratch on the recording medium 1 in step 26 is described.
This will be described with reference to the explanatory diagram of the defect type detection of the recording medium shown in FIG. FIG. 4 shows a cross-sectional view of the recording medium 1 and a waveform of an RF signal. (A) When dirt is attached to the surface of the surface protection layer A of the recording medium 1, (b) Pit forming layer of the recording medium 1 B shows a case where B has a defect and the reflection of the irradiated laser light is disturbed, and (c) a case where the surface protective layer A of the recording medium 1 is damaged. It can be seen that the waveform of the RF signal is different for each type of defect of the recording medium 1, and the type of defect of the recording medium 1 is determined from the difference in the waveform of the RF signal. In addition, since the disturbance of the waveform of the RF signal causes disturbance of the control signals of the control system of the reproducing means 2 such as a focus error signal and a tracking error signal, the time during which the disturbance occurring in these control signals occurs is shortened. And the magnitude of the disturbance generated in the control signal, the type and magnitude of the defect of the recording medium 1 are detected. However, the length of time during which the disturbance of the RF signal and the disturbance of the control signal of the control system of the reproducing means 2, such as the focus error signal and the tracking error signal, and the magnitude thereof are determined by the tracking gain, the focus gain, and the tracking offset. And the control amount of the control means of the reproducing means 2 such as the focus offset.

For the above reasons, the magnitude of signals such as RF signals, tracking error signals, and focus error signals obtained by receiving reflected light from the recording medium 1 input to the microcomputer 11 from the reproducing means 2, By reading the progress of various changes and reading the control amounts of the control system of the reproducing means 2 such as tracking gain, focus gain, tracking offset, and focus offset which are input from the control means 4 to the microcomputer 11,
From this information, it is possible to detect information on the type and size of the defect of the recording medium 1.

Next, a process for reproducing the recording medium 1 reproduced above will be described. If the recording medium 1 is mounted again on the signal recording / reproducing apparatus of this embodiment and necessary processing for reproduction is performed, in step 20, the recognition code of the recording medium 1 is input from the reproducing means 2 to the microcomputer 11 by the subcode. Then, in step 21, the recognition code of the recording medium 1 is compared with the recognition code stored in the microcomputer 11 to determine whether or not the recording medium has a reproduction error before. In this case, since a recording medium in which a reproduction error has occurred previously is used as the recording medium 1, the process proceeds to step 29, where the time code is read from the subcode input to the microcomputer 11 from the reproducing means 2, and In step 30, the time code is checked to determine whether or not the playback error occurs immediately before or during the playback error. If it has not yet reached the position immediately before the position where the reproduction error occurs, the time code is checked in step 33 to determine whether or not the position has passed the position where the reproduction error occurs. The above processing is performed in steps 22, 23, 24, 25, 26, 27, 28 and step 35, and the process returns to step 21. Then, similarly to the above-described processing, steps 21 to 29 and step 30
If the reproduction error occurs immediately before or during the position where the reproduction error occurs, the process proceeds to step 31, where information on the type and size of the defect of the recording medium 1 when the reproduction error has occurred last time is provided. Is read from the storage element of the microcomputer 11, and in step 32, the recording medium 1 is read.
Based on information on the type and size of defects
This time, the control amount of the control unit 4 which is expected to be able to reproduce the recording medium 1 without causing a reproduction error is output to the control unit 4.

Thereafter, the process proceeds to step 22 and the above-described processing is performed.
From step 22, steps 28 and 35 are performed, and the process returns to step 21. Steps 21 to 29 are performed in the same manner as in the above-described processing, and the process proceeds to step 30. If it is determined that the reproduction error has been passed this time, steps 30 to 33 are executed.
Then, at step 33, the time code is checked to determine whether or not the vehicle has passed a position where a reproduction error occurs. The control amount before the change is output to the control means 4 to return to the original state.

The reasons for performing such processing are tracking gain,
This is because the degree to which the pit information of the recording medium 1 can be correctly read for a defect such as a flaw of the recording medium 1 is changed by changing a control amount of a control system of the reproducing unit 2 such as a focus gain, a tracking offset, and a focus offset. Normally, if the tracking gain and the focus gain are reduced, the degree to which the pit information of the recording medium 1 can be correctly read with respect to a defect such as a flaw of the recording medium 1 increases, and similarly, the control amounts such as the tracking offset and the focus offset change. By doing so, it is possible to change the degree to which the pit information of the recording medium 1 can be correctly read for a defect such as a scratch that the recording medium 1 has. However, depending on the magnitude of these control amounts, even if the recording medium 1 is strong against defects such as flaws, the property that the recording medium 1 is weak against vibrations applied from the outside becomes large. Cannot be set small or the control amounts such as tracking offset and focus offset are set to extremely deviated set values. Therefore, the recording medium 1 is reproduced by changing these control amounts only when necessary. In other cases, the control amount is normally set, that is, the recording medium 1 is resistant to disturbances such as vibrations applied from the outside. It is necessary to perform a process of setting a control amount having a strong reproduction capability even for a certain degree of defect and reproducing the defect.

As described above, the functions of the recording medium recognizing means 5 are performed in Steps 20 and 21, the function of the position detecting means 6 is performed in Steps 22 and 23, the function of the detecting means 3 is performed in Steps 24 and 29, and the function of the detecting means 3 is determined in Step 26. The function of the detecting means 10 is
The functions of the generation storage means 7 are described in steps 29, 30, 30, 31,
2. The functions of the predicting means 8 and the avoiding means 9 are realized by the steps 33 and 34.

As described above, according to the present embodiment, once the occurrence of a defect in the recording medium is detected, information necessary to avoid the influence of the defect in the recording medium, such as the position where the defect occurs, is stored. In the case where the same recording medium is reproduced next time, the influence of the defect is controlled by controlling the reproducing means based on the stored information before the defective portion of the recording medium is reproduced. Thus, it is possible to provide a signal recording / reproducing apparatus capable of reproducing information on a recording medium without error by avoiding the above problem.

In this embodiment, the functions of the detecting means, the recording medium recognizing means, the position detecting means, the generating and storing means, the predicting means, the avoiding means, and the defect detecting means are realized by a single microcomputer. The functions may be realized by a single microcomputer, or all or some of these functions may be realized by a general-purpose integrated circuit other than the microcomputer.

Further, in this embodiment, as the recognition code for individually recognizing the recording medium by the recording medium recognizing means, the recorded content information from the subcode recorded on the recording medium is read, and based on this recorded content information. The recognition code is created and used as a recognition code. The recognition code is read from the recorded content information display such as a barcode format written on a label attached to the surface of the recording medium, and the recognition code is created based on this. You may use it.

Further, in this embodiment, as a method of detecting a defect of the recording medium in the detecting means, a method of detecting an error detection signal such as a focus error signal, a tracking error signal, and a muting signal input from the reproducing means to the microcomputer is used. Although a method is used, a method of optically exploring the surface of the recording medium with a light source and an imaging element such as a CCD element to detect a defect of the recording medium may be used.

Further, in this embodiment, as a method of detecting information relating to the type and size of a defect of the recording medium in the defect detecting means, a control signal such as a focus error signal and a tracking error signal input from the reproducing means to the microcomputer and a reproducing signal are used. A method of detecting based on the control amount of the control system of the means is used, but the type and size of the defect that the recording medium has by optically exploring the surface of the recording medium with a light source and an imaging element such as a CCD element May be used.

In the above-described embodiment, the case where the type and size of the defect is described as the defect information of the recording medium has been described. However, the present invention can be realized even when the defect information is only the type or the size. .

As described above, the present invention provides a reproducing unit that reproduces a recording medium on which a signal is recorded, a recording medium recognizing unit that individually recognizes the recording medium, and a current signal reproducing position of the recording medium. Position detecting means for detecting, detecting means for detecting a defect of the recording medium while reproducing the recording medium, control means for controlling the reproducing means, and an output of the reproducing means and an output of the control means. A defect detection unit for detecting information on a defect of the recording medium while reproducing the recording medium; an output of the recording medium recognition unit, an output of the position detection unit, an output of the detection unit, and an output of the defect detection unit Generating storage means for storing information for individually identifying the recording medium, an occurrence position of a defect of the recording medium, and information on the defect of the recording medium, and the recording medium Based on the output of the recognizing means, the output of the occurrence storage means, and the output of the position detecting means, the occurrence position of the defect of the recording medium is predicted while the recording medium is being reproduced, and the influence of the defect of the recording medium is avoided. Predicting means for predicting the control amount of the control means necessary for the control, and controlling the control amount of the control means from immediately before a position where a defect of the recording medium has occurred based on the output of the predicting means while reproducing the recording medium. Changing means for controlling the reproducing means to avoid the influence of a defect of the recording medium,
Once a playback point reaches a defect or scratch and its presence is detected, the information can be detected so that defects that occur during the manufacturing process of the recording medium and scratches that occur during use can be detected in advance during playback. In advance, the position where a defect or a scratch is generated is detected in advance at the next reproduction, and the reproducing unit is controlled based on the information stored before the defective portion of the recording medium is reproduced. By doing so, the effect of the defect can be avoided and the information possessed by the recording medium can be reproduced without error.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of an embodiment of a signal recording / reproducing apparatus of the present invention, FIG. 2 is a block diagram showing a specific configuration of an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. 4 is a flowchart showing a main part of the processing operation of the microcomputer, FIG. 4 is an explanatory diagram of detection of a defect type of the recording medium,
FIG. 5 is a block diagram showing the overall configuration of a conventional signal recording / reproducing apparatus. 2 ... reproduction means, 3 ... detection means, 4 ... control means, 5
... Recording medium recognizing means 6, position detecting means 7, generating storage means 8, predicting means 9, avoiding means 10,
Defect detection means.

Claims (1)

(57) [Claims] 1. A reproducing means for reproducing a recording medium on which a signal is recorded, a recording medium recognizing means for individually recognizing the recording medium, and a position detecting means for detecting a current signal reproducing position of the recording medium. Detecting means for detecting a defect of the recording medium during reproduction of the recording medium; control means for controlling the reproduction means; and reproduction of the recording medium by an output of the reproduction means and an output of the control means. Defect detection means for detecting information about the defect of the recording medium,
Information for individually identifying the recording medium based on the output of the recording medium recognizing means, the output of the position detecting means, the output of the detecting means, and the output of the defect detecting means; Generating storage means for storing information relating to a defect of the recording medium, the output of the recording medium recognizing means, the output of the generating storage means, and the output of the position detecting means having the recording medium during reproduction of the recording medium; Predicting means for predicting the position of the defect and predicting the control amount of the control means necessary to avoid the influence of the defect on the recording medium, and based on the output of the predicting means during reproduction of the recording medium. The influence of the defect of the recording medium is avoided by controlling the reproducing means by changing the control amount of the control means immediately before the position where the defect of the recording medium has occurred. Signal recording and reproducing apparatus characterized by comprising a avoidance means that.