JP3831088B2 - Optical disc recording / reproducing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical disk recording / reproducing apparatus for recording / reproducing information on / from an optical disk, and in particular, an optical disk recording / reproducing apparatus capable of effectively preventing a recording / reproducing error due to an inclination or eccentricity of the optical disk. And an error recovery method applicable to the apparatus.
[0002]
[Prior art]
With the development of an advanced information society, development of an optical disk recording / reproducing apparatus capable of recording information with high accuracy and high density on an optical disk as an information storage medium or reproducing such recorded information has been developed. Has been promoted. Examples of the optical disc applied to this apparatus include a compact disc (CD), a laser disc (LD), a digital video disc (DVD, also referred to as “digital versatile disc”) for reproduction or recording / reproduction. It is done. Of these, a DVD capable of ultra-high capacity is attracting attention.
[0003]
Unlike a fixed magnetic disk device (hard disk device) or the like, an optical disk recording / reproducing device can exchange a recording medium, that is, an optical disk. The optical disk recording / reproducing apparatus has a disk rotating mechanism composed of, for example, a spindle motor for rotationally driving the optical disk, and uses a clamp mechanism to chuck the optical disk inserted into the optical disk recording / reproducing apparatus on the spindle motor turntable. It is supposed to be king.
[0004]
In such an optical disk storage device, the accuracy when the optical disk is chucked to the disk rotation mechanism greatly affects the information recording / reproducing operation. That is, if the optical disk is chucked in a tilted state, or if the optical disk is chucked in a state of being eccentric with respect to the disk rotation mechanism, the information recording / reproducing operation becomes impossible in the worst case.
[0005]
If the optical disk is chucked in a tilted state, an error in the axis of the optical system called a tilt angle increases. The tilt angle (also simply referred to as “tilt”) is an angle formed by the vertical axis with respect to the recording surface of the optical disc and the optical axis of the optical pickup. If this tilt exceeds the allowable range, information recording / reproduction is practically impossible.
[0006]
If the optical disk is chucked in an eccentric state, a track error occurs in which the light beam spot deviates from the optical disk track. This error is called a track error, and if the allowable range is exceeded as in the case of the tilt angle, information recording / reproduction is practically impossible.
[0007]
In particular, recently developed optical discs, especially large-capacity optical discs such as DVDs, have a very high information recording density. Therefore, in order to perform accurate recording / reproduction, the tilt angle or track error is more It is necessary to manage severely.
[0008]
For this reason, an optical disc apparatus that performs high-density recording / reproduction is provided with a mechanism for correcting the tilt of the optical disc using a servo motor and a mechanism for causing the optical axis of the optical pickup to follow the tilt angle. ing.
[0009]
[Problems to be solved by the invention]
As described above, particularly in a high recording density optical disc apparatus, the tilt angle depending on the disc tilt generated when the optical disc is chucked to the disc rotation mechanism, or the track error depending on the eccentricity deviation of the optical disc may cause the recording / reproducing operation. It is becoming a major factor in disability.
[0010]
For this reason, a servo mechanism or the like for correcting the tilt angle is required, which causes a complicated apparatus configuration and high cost. On the other hand, if the tolerance for manufacturing the optical disk or the disk rotating mechanism is very strict, the manufacturing cost increases.
[0011]
The present invention has been made in view of the circumstances as described above, and an object of the present invention is to eliminate a tilt (tilt angle) or eccentricity (track error) generated during chucking of an optical disk without requiring a complicated correction mechanism. An object of the present invention is to provide an optical disc recording / reproducing apparatus that can be effectively reduced.
[0012]
[Means for Solving the Problems]
The present invention relates to an optical disc recording / reproducing apparatus for recording or reproducing recorded information from an optical disc by an optical head in a state where the optical disc is chucked and rotated by a disc rotating mechanism, and the tilt angle of the optical disc during the rotating operation Detecting means for detecting the detection angle, determining means for determining whether or not the tilt angle detected by the detecting means is within an allowable range, and when the determining means determines that the tilt angle exceeds the allowable range And a control means for performing the chucking operation on the optical disk again, and the control means releases the optical disk from the disk rotation mechanism and then moves the disk rotation mechanism. When the tilt angle in one rotation period of the optical disk is distributed, the phase from which the maximum tilt angle is obtained It is characterized in that chucking is executed again after being rotated by a predetermined degree.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, first to tenth embodiments of the present invention will be described with reference to the drawings.
(System configuration)
First, an apparatus configuration common to the first to tenth embodiments of the present invention will be described with reference to the block diagram shown in FIG.
[0025]
In FIG. 1, reference numeral 1 denotes an optical disk as an information storage medium. The optical disk storage device of this embodiment includes an optical disk exchanging mechanism for exchanging the optical disk 1. This mechanism has a disc tray 2 for holding the optical disc 1 and a drive motor 3 for driving the disc tray 2 in the horizontal direction.
[0026]
This optical disk exchanging mechanism drives the optical disk 1 in the horizontal direction, and inserts it between the spindle motor 7 and the clamper 4 that are opposed to each other in the vertical direction. The clamper 4 and the spindle motor 7 are driven in the vertical direction by the respective moving mechanisms 5 and 8 and the motors 6 and 9 so as to chuck the central portion of the optical disc 1 in the vertical direction. The spindle motor 7 is connected to a motor driving circuit 10 and rotationally drives the chucked optical disk 1 at a predetermined rotational speed.
[0027]
Further, this apparatus controls the optical pickup 11 for recording / reproducing information on the optical disc 1, the optical pickup moving mechanism 12 for driving the optical pickup 11, and the optical pickup moving mechanism 12. And an optical pickup driving circuit 13.
[0028]
Reference numerals 14 and 15 denote a system controller and a memory as a main control device of this apparatus. The system controller 14 includes a microprocessor (CPU) as a main component, and controls the motors 3, 6, 9 and the motor drive circuit 10 in addition to the optical pickup drive circuit 13.
[0029]
As will be described later, the system controller 14 is provided with a tilt detector 14a that detects a tilt angle based on an output from the optical pickup 11 and a track error detector 14b that detects a disc eccentricity (track error value). Yes.
[0030]
The tilt detector 14a and the track error detector 14b calculate the tilt angle and the track error value (disc eccentricity) by using the measured value of the reflected laser light emitted from the optical pickup 11 and reflected by the optical disc 1. . Specifically, using a four-division photodiode of an optical system built in the optical pickup 11 or the like, based on the change of the output signal and preset distance and angle information, the radial direction and the tangential direction The tilt angle and track deviation amount are calculated.
[0031]
The memory 15 stores a tilt angle (T) and a track error value (E) detected by the system controller 14, and various controls necessary for a tilt adjustment operation and a track error adjustment operation as will be described later. Used to store information.
(First embodiment)
Next, a first embodiment of the present invention will be described with reference to FIGS.
[0032]
As shown in the flowchart of FIG. 2, the first embodiment relates to a tilt adjustment method that re-executes chucking of the optical disc 1 when the tilt value T detected by the tilt detector 14a exceeds an allowable range. is there.
[0033]
As shown in step S1 of FIG. 2, first, when the user places the optical disc 1 on the disc tray 2 and operates, for example, an insertion / ejection switch, the motor 3 is activated and the optical disc 1 is stored in the apparatus. (State shown in FIG. 1). Next, the system controller 14 drives and controls the motors 6 and 9, lowers the clamper 4 by the clamper moving mechanism 5, and raises the spindle motor 7 by the spindle motor moving mechanism 8.
[0034]
Thereby, the optical disk 1 is chucked by being clamped by the clamper 4 on the turntable of the spindle motor 7 (step S2). Then, the system controller 14 controls the motor drive circuit 10 and operates the spindle motor 7 to rotate the optical disc 1 (step S3).
[0035]
At this time, a magnetic path is formed between a magnet (not shown) provided at the center of the spindle motor 7 and the clamper 4 whose contact surface is made of a magnetic material. By this magnetic force, the optical disk 1 is securely held on the turntable of the spindle motor 7 and rotates stably without being separated from the spindle motor 7.
[0036]
Next, the tilt detector 14a of the system controller 14 calculates the tilt angle (shown as a tilt value T) of the optical disc 1 based on the detection signal from the optical pickup 11 (step S4). Further, the system controller 14 compares the detected tilt value T with a specified value (allowable value) T0 previously stored in the memory 15 (step S5).
[0037]
If the comparison result is within the allowable range (T ≦ T0), the system controller 14 proceeds to a normal information recording / reproducing operation for the optical disc 1 (YES in step S6, S7). That is, the system controller 14 controls the optical pickup moving mechanism 12 and the optical pickup driving circuit 13 to move the optical pickup 11 to the target position, and record or reproduce information on the access target position of the optical disc 1. To do.
[0038]
On the other hand, if the detected tilt value T is outside the allowable range (T> T0), the system controller 14 executes the following tilt adjustment processing. That is, the system controller 14 first controls the spindle motor 7 to stop the rotation of the optical disc 1 (step S8). Next, the clamper moving mechanism 5 raises the clamper 4 and the spindle motor moving mechanism 8 lowers the spindle motor 7 to unchuck (release) the optical disk 1 (step S9).
[0039]
Then, after the spindle motor 7 is rotated for a predetermined time or a predetermined angle and stopped, the optical disk 1 is chucked again (steps S10 to S12). That is, the system controller 14 controls the motors 6 and 9 to lower the clamper 4 by the clamper moving mechanism 5 and raise the spindle motor 7 by the spindle motor moving mechanism 8.
[0040]
In this re-chucking state, the spindle motor 7 is driven again to rotate the optical disc 1 (step S3). Then, the tilt detection and determination process is re-executed. In this case, if the tilt detection value T is outside the allowable range, the unchucking and chucking operations are further repeated. The system controller 14 repeats the unchucking / chucking operation until the tilt detection value T falls within the allowable range, up to a predetermined number of times set in advance (step S13).
[0041]
If the tilt detection value T is outside the allowable range even after repeating the specified number of times, the system controller 14 determines that the tilt angle cannot be recovered, and proceeds to a predetermined error process (step S14). As the error processing, for example, the host system or the user may be notified that an error has occurred in the inserted optical disk 1. Alternatively, the optical disk 1 may be released from the disk rotating mechanism and automatically ejected while being placed on the disk tray.
[0042]
According to the above configuration, even when an excessive tilt angle occurs, it is possible to correct the tilt angle to be within a predetermined allowable range by performing an unchucking / chucking operation of the optical disc. become.
[0043]
That is, the occurrence of the tilt angle is due to the fact that the optical disc 1 is chucked in a tilted state. In this embodiment, the occurrence of a tilt angle is detected immediately after chucking by using an optical pickup, and an unchucking / chucking operation is performed again, thereby changing the chucking posture with respect to the optical disc, thereby changing the tilt angle. Can be adjusted (corrected).
[0044]
3A and 3B show experimental data obtained by measuring the relationship between the number of times of chucking operation (number of adjustments) and the detected tilt value (normalized tilt amount T) according to this embodiment. . Here, the specified tilt value (allowable value) T0 is "3.0".
[0045]
As shown in FIG. 3A, in trial 1, the number of adjustments (the number of re-chucking) is the second time, and is corrected within an allowable range less than the specified value. In trial 2, it is within the allowable range from the time of the first chucking, and the allowable range is maintained in the subsequent chucking operation. In trial 3, it is corrected within the allowable range at the first time. In trial 3, the value is increased to the specified value at the fourth time. However, in the method of this embodiment, the chucking position at the time of correction within the allowable range is set. There is no.
[0046]
FIG. 3B is a diagram showing a frequency distribution (histogram) of measurement results obtained by measuring the tilt value T 40 times for each chucking adjustment. In this figure, the horizontal axis represents the normalized tilt amount, and the vertical axis represents the frequency of each normalized tilt amount. With respect to the specified tilt value (3.0), two errors (including 3.0) have occurred in 40 measurements. From this, it can be estimated that a tilt error occurs due to chucking with a probability of 5%. In other words, when a tilt error occurs, it can be estimated that the tilt error can be reduced with a probability of about 95% by re-chucking.
(Second Embodiment)
The second embodiment relates to control for correcting the tilt angle of the optical disc 1 by accelerating / decelerating the spindle motor 7. Hereinafter, this embodiment will be described with reference to FIG.
[0047]
First, when the optical disc 1 is placed on the disc tray 2 and inserted into the apparatus, the optical disc 1 is placed on the turntable of the spindle motor 7 by the clamper 4 and the spindle motor 7 as described above. It is chucked so as to be sandwiched (steps S20 and S21). When the optical disc 1 is rotated, the tilt detector 14a of the system controller 14 detects the tilt angle of the optical disc 1 during the rotating operation by the spindle motor 7, and performs a determination process with the specified value (allowable value) T0. (Steps S22 to S24).
[0048]
In the second embodiment, when the detected tilt value T is outside the allowable range (T> T0), the following tilt adjustment processing is executed. First, the drive of the spindle motor 7 is stopped, and the rotation of the optical disk 1 is stopped (step S27). Thereafter, the system controller 14 controls the spindle motor 7 again to accelerate the spindle motor 7 or execute control to alternately repeat acceleration / deceleration (step S28). Then, the tilt detection and determination process is re-executed.
[0049]
In this case, if the tilt detection value T is outside the allowable range, the tilt adjustment process is further repeated. If the tilt detection value T is out of the permissible range even after repeating the specified number of times, the system controller 14 determines that the tilt angle cannot be recovered and proceeds to a predetermined error process (steps S29 and S30). .
[0050]
According to such a configuration, unlike the first embodiment, the tilt of the optical disc can be corrected without releasing the optical disc 1 from the disc rotation mechanism. That is, the optical disk 1 can be slid on the turntable of the spindle motor 7 by accelerating or accelerating / decelerating the rotational speed of the spindle motor 7 in the chucked state. The combined state (chucking posture) can be changed.
[0051]
As a result, the tilt of the optical disc 1 can be corrected in the same manner as in the first embodiment, so that the tilt angle can be corrected within an allowable range.
(Third embodiment)
In the first or second embodiment described above, there may be a case where the tilt angle is not corrected within the allowable range even if the tilt adjustment processing exceeds the specified number j. The third embodiment relates to a specific example of error processing in this case. Hereinafter, this embodiment will be described with reference to FIGS.
[0052]
That is, if the detected tilt value T is outside the allowable range based on a comparison between the detected tilt value T and the specified value T0, the system controller 14 executes a tilt adjustment process (steps S37 to S39). Note that the previous processes (steps S31 to S36) are the same as those in the first or second embodiment described above, and thus the description thereof is omitted.
[0053]
As described above, the system controller 14 repeats the tilt angle adjustment process (number of times i) up to the specified number of times j until the tilt angle is corrected within the allowable range (steps S35 to S40). Then, when the number of tilt angle adjustment processes i exceeds the specified number j, error processing shown in steps S45 to S48 in FIG. 6 is executed.
[0054]
That is, the system controller 14 outputs a tilt error signal to, for example, a personal computer or a television receiver that is a host system (step S45). In response to the tilt error signal, a message such as a “disc playback error” or a symbol mark is displayed on the screen of the display device of the personal computer or the television receiver. Alternatively, a process of generating a warning sound via a speaker and notifying the user may be performed. Further, the system controller 14 stops the spindle motor 7, releases the optical disk 1 from the disk rotation mechanism, and ejects it from the apparatus (steps S46 to S48).
[0055]
By the way, in step 38 of FIG. 5, if the detected tilt value T is equal to or less than the specified value T0, the system controller 14 determines that the tilt angle is within the allowable range and tries to shift to a normal recording / reproducing operation. (Step S42).
[0056]
However, here, for example, when the detected tilt value T is substantially the same as the prescribed value T0, the probability of occurrence of a reproduction error due to the tilt angle increases. Therefore, the system controller 14 sets a reference value T1 (e.g., 2.9 when T0 is 3.0) that is stricter than the specified value T0, and when the detected tilt value T exceeds the reference value T1. The detected tilt value T is recorded as tilt information, for example, at a predetermined position on the optical disc 1 (steps S41 and S43).
[0057]
The detected tilt value is represented by T (r, φ). Here, r is a radial position, and φ is a parameter that physically or logically defines a position on the optical disk 1 that means a phase. Therefore, the tilt value T is recorded on the optical disc together with the position where the tilt value T is generated. The tilt value thus recorded can be used as maintenance information of the optical disc 1 or the drive, for example, in addition to not recording information at the position in the recording / reproducing operation of step S42 (step S44).
(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIG.
[0058]
In the fourth embodiment, an eccentricity deviation amount (referred to as a track error value (value E)) in the chucking state of the optical disc 1 is detected, and the track error value E is outside the allowable range (E0). The present invention relates to a control method for executing error adjustment processing (track error recovery processing).
[0059]
First, as shown in steps S50 to S52 of FIG. 7, the system controller 14 chucks the optical disk 1 on the turntable of the spindle motor 7 and rotates it. In this state, a track error detection process is executed (step S53). That is, the system controller 14 performs the process determination shown in steps S53 to S55, and if the detected track error value E is outside the specified value E0 (allowable range), executes the track error adjustment process described below (steps). S57 to S62).
[0060]
First, the system controller 14 controls the spindle motor 7 to stop the rotation of the optical disc 1 (step S57). Next, the optical disk 1 is unchucked (released) from the disk rotation mechanism, and the spindle motor 7 is rotated for a predetermined time to be stopped. Next, the optical disk 1 is chucked again (steps S58 to S61).
[0061]
In this re-chucking state, the spindle motor 7 is driven again to rotate the optical disc 1 (step S52). Then, the track error detection determination process (S53 to S55) is re-executed. At this time, if the track error detection value E is outside the allowable range, the above-described unchucking / chucking operation is further repeated. The system controller 14 repeats the above-described operation until the track error detection value E falls within the allowable range, up to a predetermined number of times set in advance (step S62).
[0062]
If the track error detection value E is out of the allowable range even after repeating up to the specified number of times, the system controller 14 determines that the recovery of the track error is impossible, and proceeds to a predetermined error process (step S63).
[0063]
According to such a configuration, when the detection amount is outside the allowable range, the chucking posture of the optical disc 1 can be changed by performing the unchucking and chucking operations of the optical disc 1. The eccentric deviation can be corrected. This can prevent track errors during recording / reproduction.
(Fifth embodiment)
The fifth embodiment relates to control for correcting the track error value by performing acceleration / deceleration of the spindle motor 7 when a track error value E outside the allowable range is detected. Hereinafter, this embodiment will be described with reference to FIG.
[0064]
First, when the optical disc 1 is placed on the disc tray 2 and stored in the apparatus in step S70, the optical disc 1 is placed on the turntable of the spindle motor 7 and the clamper 4 and the spindle motor as described above. 7 and is chucked so as to be sandwiched between them (step S71). Then, the system controller 14 detects the track error value E of the rotating optical disc 1, and performs a comparison determination process with a specified value (allowable value) E0 (steps S73 to S74).
[0065]
In the fifth embodiment, when the detected track error value E is outside the allowable range (E> E0), the following track error adjustment processing is executed (steps S77 to S80).
[0066]
First, the motor 9 is controlled to stop driving the spindle motor 7 and stop the rotation of the optical disc 1 (step S77). Thereafter, the system controller 14 controls the motor 9 again to accelerate the spindle motor 7 or execute control to alternately repeat acceleration / deceleration (step S78). Then, the track error detection and the comparison determination process are re-executed (steps S72 to S75). In this case, if the track error detection value E is outside the allowable range, the track error adjustment process is further repeated.
[0067]
If the track error detection value E is out of the allowable range even after repeating up to the specified number of times, the system controller 14 determines that the recovery of the track error value is impossible and shifts to a predetermined error process (step S79). , S80).
[0068]
According to such a configuration, the optical disk 1 is not released (unchucked) from the spindle motor 7, but the spindle motor 7 is stopped once and accelerated / decelerated while the optical disk 1 is chucked. Value correction can be performed. That is, by accelerating or decelerating the spindle motor 7 at a predetermined acceleration, a slip can be generated between the chucked optical disc 1 and the turntable of the spindle motor 7 to change the chucking posture of the optical disc. . As a result, the amount of eccentric deviation of the optical disc 1 can be corrected, so that the track error value can be adjusted to be within an allowable range.
(Sixth embodiment)
In the fourth or fifth embodiment described above, there may be a case where the tilt angle is not corrected within the allowable range even if the track error value adjustment processing exceeds the specified number j. The sixth embodiment relates to a specific example of error processing in this case. Hereinafter, this embodiment will be described with reference to FIGS.
[0069]
That is, if the detected track error value E is outside the allowable range by comparing the detected track error value E with the specified value E0, the system controller 14 executes a track error adjustment process (steps S87 to S89). Note that the previous processes (steps S81 to S86) are the same as those in the above-described fourth or fifth embodiment, and thus description thereof is omitted.
[0070]
As described above, the system controller 14 repeats the track error adjustment process (number of times i) up to the specified number of times j until the track error value is corrected within the allowable range (steps S85 to S90). Then, when the number of track error adjustment processes i exceeds the specified number j, the error process shown in steps S95 to S98 in FIG. 10 is executed.
[0071]
That is, the system controller 14 outputs a tilt error signal to, for example, a personal computer that is a host system or a television receiver (step S95). In response to the tilt error signal, a message such as a “disc playback error” or a symbol mark is displayed on the screen of the display device of the personal computer or the television receiver. Alternatively, a process of notifying the user by generating a warning sound or lighting an LED through a speaker may be used. Further, the system controller 14 stops the spindle motor 7, releases the optical disk 1 from the disk rotation mechanism, and ejects it from the apparatus (steps S96 to S98).
[0072]
By the way, in step 88 of FIG. 9, if the detected track error value E is equal to or less than the specified value E0, the system controller 14 determines that the track error value is within the allowable range and proceeds to normal recording / reproducing operation. (Step S92).
[0073]
However, here, for example, when the detected track error value E is substantially the same as the specified value E0, the probability of occurrence of a reproduction error due to the track error increases. Therefore, the system controller 14 sets a reference value E1 that is stricter than the specified value E0. If the detected track error value E exceeds the reference value E1, the detected track error value E is used as track error information, for example. Recording is performed at a predetermined position on the optical disc 1 (steps S91 and S93).
[0074]
The detected track error value is represented by E (r, φ). Here, r is a radial position, and φ is a parameter that physically or logically defines a position on the optical disk 1 that means a phase. Therefore, the track error value E is recorded on the optical disc together with the position where the track error value E is generated. The track error value recorded in this way is used as maintenance information of the optical disc 1 or the drive, for example, in addition to not recording information at the position (step S94).
(Seventh embodiment)
The seventh embodiment relates to a control that performs both the tilt detection and the track error detection described above and performs the tilt adjustment process and the track error adjustment process described in the first to sixth embodiments based on the detection. is there. In the seventh embodiment, the unchucking / chucking operation of the optical disc 1 is performed as tilt adjustment processing and track error adjustment processing. Hereinafter, this embodiment will be described with reference to FIGS.
[0075]
First, as shown in FIG. 11, the system controller 14 detects the tilt angle and executes the determination process with the specified value in a state where the optical disk 1 is chucked and rotated by the disk rotation mechanism (step S100). To S106). The system controller 14 repeats the tilt adjustment process (here, the chucking adjustment process) up to the specified number j until the tilt angle is corrected within the allowable range (steps S107 to S104). When the number of tilt adjustment processes i exceeds the specified number j, the error process shown in steps S45 to S48 in FIG. 6 is executed.
[0076]
Here, in the present embodiment, the system controller 14 determines that the reference value is stricter than the specified value T0 as described above when the detected tilt value T is corrected within the allowable range by the tilt adjustment processing within the specified number j. A determination process based on T1 is performed (step S110). When the detected tilt value T exceeds the reference value T1, the system controller 14 records the detected tilt value T as a tilt information at a predetermined position on the optical disc 1, and the next time regardless of the comparison result. The process proceeds to track error detection processing (steps S110 to S112).
[0077]
Next, as shown in FIG. 12, the system controller 14 determines whether or not the detected track error value E is within an allowable range by comparing the detected track error value E with a specified value E0 (step). S113 to S116). The system controller 14 repeats the track error adjustment process (here, the chucking adjustment process) up to the specified number m until the track error value is corrected within the allowable range (steps S113 to S118). When the number k of track error adjustment processes exceeds the specified number m, the error process shown in steps S95 to S98 in FIG. 10 is executed.
[0078]
Here, the system controller 14 is based on the reference value E1 that is stricter than the specified value E0, as described above, when the detected track error value E is corrected within the allowable range by the adjustment processing within the specified number m. A determination process is performed (step S119). When the detected track error value E exceeds the reference value E1, the system controller 14 records the detected track error value E at a predetermined position on the optical disc 1 as track error information. Then, the process proceeds to the recording / reproducing operation shown in step S120 (step S120).
[0079]
The tilt information (position information) and track error information (position information) recorded on the optical disc 1 are used to prevent information from being recorded at the position during the recording / reproducing operation shown in step S120. . In addition, for example, it is used as maintenance information of the optical disc 1 or the drive (S122).
[0080]
In this embodiment, the prescribed number j of tilt angle adjustments and the prescribed number m of track error adjustments may be set individually or may be defined by the total number of adjustment processes.
[0081]
In this embodiment, the re-chucking operation for adjusting the tilt angle and adjusting the track error is performed at the same time, but may be performed separately.
(Eighth embodiment)
In the first to seventh embodiments, the tilt angle detection and the track error value detection are continuously sampled over the entire circumference of the optical disc. Alternatively, a method of sampling in a scattered manner from the logical address may be used. That is, this embodiment relates to a method for detecting a tilt angle and a track error value in a fixed phase set to be discrete on the optical disc 1.
[0082]
When considering the generation of the tilt angle, the 0, 1, 2 and 3rd order components of the relatively low frequency disk rotation speed are almost all. Therefore, in one rotation of the disc, the state of tilt can be reproduced by sampling about 10 times, and it is not necessary to calculate the tilt angle continuously. This embodiment focuses on this point.
[0083]
However, since the influence is large when the tilt angle of the error is small, it is desirable to set the detection amount as the average or worst value of a plurality of measurements at one point on the disk.
[0084]
Further, the tilt angle is detected by using a counter electromotive current waveform generated in synchronization with the rotation of the spindle motor 7 and sampling in synchronization with a rotation synchronization signal of, for example, 6 pulses per rotation and substantially equal phase intervals. But you can. Further, since the tilt angle varies depending on the disk radius position, the sample may be sampled only on the outer peripheral side where the influence of general disk distortion is large, or an error may be determined from sampling data of a plurality of radii. In addition, a method of sampling data at an equal time interval of “T / 6 (seconds), for example, if the rotation cycle is T (seconds), may be estimated from the number of rotations of the spindle motor 7.
(Ninth embodiment)
The ninth embodiment outputs a tilt error signal when the number of tilt adjustments i exceeds a specified number j in the error processing by the tilt adjustment processing, and for example, a normal track provided on the innermost circumference of the optical disc 1. In this method, tilt error information is recorded in a three-fold area.
[0085]
Here, since the tilt angle is larger than the specified value, even when information cannot be recorded / reproduced on a normal track, for example, it is limited to a part of the outer periphery or the tilt angle is large in a certain angle region. It can be fully expected that the area is less than the specified value.
[0086]
Further, for example, by increasing the track width of a partial area such as the inner circumference side, recording / reproduction may be possible if the warp of the optical disk is within a certain range. Therefore, for example, by securing a special recording area on the innermost circumference of the disc 1, it is possible to save history information such as the tilt angle and the number of tilt errors.
[0087]
Of course, the history information may be recorded on a normal track while using tilt servo processing together.
(Tenth embodiment)
The tenth embodiment relates to an apparatus for correcting the tilt angle by the operation of unchucking / chucking among the above-described embodiments. After the unchucking in this apparatus, the spindle motor 7 is rotated by a predetermined phase. The present invention relates to control for executing chucking again after the rotation.
[0088]
Hereinafter, this embodiment will be described with reference to FIG. Note that the same components and operations as those of the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
In this embodiment, a phase detector 131 that detects the rotational phase of the spindle motor 7 is used. Examples of the phase detector 131 include a rotation pulse generation device and a counter electromotive force pulse generation device using an encoder plate.
[0089]
The detection signal from the phase detector 131 is processed by the rotational phase detector 132 provided in the system controller 14. The phase detection result is processed by the tilt angle distribution logic operation circuit 133 provided in the system controller 14 together with the tilt angle detected by the tilt angle detector 14a. That is, the tilt angle distribution logic operation circuit 133 calculates the tilt angle distribution over the entire circumference of the optical disc 1 by associating the rotational phase of the spindle motor 7 with the tilt angle on a one-to-one basis. This tilt angle distribution is stored in the memory 15 and passed to the chucking phase calculation unit 134.
[0090]
The chucking phase calculation unit 134 determines a chucking phase based on the tilt angle distribution. That is, in this embodiment, when the tilt angle exceeds a reference value, the optical disc 1 is released (unchucked) and rechucked. Then, while releasing the optical disc 1, the spindle motor 7 is rotated to change the chucking position. The rotation phase of the spindle motor 7 at this time is called a chunking phase.
[0091]
For example, when the tilt angle has a sinusoidal distribution with respect to one rotation period, the chucking phase calculation unit 134 determines a position shifted by 90 ° or 180 ° from the phase at which the maximum tilt angle is obtained. Chucking phase.
[0092]
Next, based on the chucking phase determined by the chucking phase calculator 134, the system controller 14 controls the motor driving circuit 10 to rotate the spindle motor 7. Next, after re-chucking the optical disk, the tilt angle is measured and compared again.
[0093]
According to such a configuration, it is possible to estimate the optimal chucking position for correcting the tilt angle, so that the tilt angle can be corrected with a small number of corrections.
[0094]
Note that the technique of the eighth embodiment can also be applied to a technique of performing correction by accelerating / decelerating the spindle motor 7 and to correcting a track error.
When correction is performed by accelerating and decelerating the spindle motor 7, it is determined in advance how much the phase shift between the optical disc 1 and the turntable of the spindle motor 7 occurs with respect to the acceleration applied to the spindle motor 7 and its duration. It is stored in the memory 15 or the like. And the process similar to the above can be performed by using the data.
[0095]
In addition, when used for correcting a track error, the correction is basically performed based on the theory that the track error value can be eliminated by correcting the shift in the direction where the track error value is shifted by 180 ° from the maximum position. Like that.
In addition, this invention is not limited to the said 1st-10th embodiment, A various deformation | transformation is possible in the range which does not change the summary of invention.
[0096]
【The invention's effect】
As described in detail above, according to the present invention, the tilt angle depending on the tilt of the disk generated when the optical disk is chucked to the disk rotating mechanism, or the track error value depending on the eccentricity of the rotating disk is detected. Thus, it is possible to effectively reduce the tilt angle or the track error value without adding a special correction mechanism.
[0097]
Therefore, reliable information recording or reproducing operation can be realized without complicating the configuration and increasing the cost associated with the addition of the correction mechanism. In addition, in the manufacturing process of the apparatus, there is no need for special high accuracy in the manufacturing accuracy of the optical disk and the assembly accuracy of the disk rotating mechanism, and therefore, there is an effect that the manufacturing cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a main part of an optical disk storage device according to the present invention.
FIG. 2 is a flowchart for explaining the operation of the first embodiment;
FIG. 3 is a diagram showing experimental data for explaining the effect of the first embodiment.
FIG. 4 is a flowchart for explaining the operation of the second embodiment;
FIG. 5 is a flowchart for explaining the operation of the third embodiment;
FIG. 6 is a flowchart for explaining the operation of the third embodiment;
FIG. 7 is a flowchart for explaining the operation of the fourth embodiment;
FIG. 8 is a flowchart for explaining the operation of the fifth embodiment;
FIG. 9 is a flowchart for explaining the operation of the sixth embodiment;
FIG. 10 is a flowchart for explaining the operation of the sixth embodiment;
FIG. 11 is a flowchart for explaining the operation of the seventh embodiment;
FIG. 12 is a flowchart for explaining the operation of the seventh embodiment;
FIG. 13 is a schematic configuration diagram for explaining a tenth embodiment.
[Explanation of symbols]
1 ... Optical disc
2 ... Disc tray
3 ... Drive motor (disc tray motor)
4 ... Clamper
5. Clamper moving mechanism
6 ... Drive motor (clamper moving mechanism motor)
7 ... Spindle motor
8 ... Spindle motor moving mechanism
9 ... Drive motor (motor for spindle motor moving mechanism)
10 ... Motor drive circuit (motor for spindle motor)
11 ... Optical pickup
12 ... Optical pickup moving mechanism
13. Optical pickup drive circuit
14 ... System controller (control means)
15 ... Memory

Claims (2)

An optical disc recording / reproducing apparatus for recording or reproducing recorded information from the optical disc by an optical head in a state where the optical disc is chucked and rotated by a disc rotating mechanism,
Detecting means for detecting a tilt angle of the optical disc during rotation;
Determination means for determining whether the tilt angle detected by the detection means is within an allowable range;
Control means for re-chucking the optical disc when the determination means determines that the tilt angle exceeds an allowable range;
The control means releases the optical disk from the disk rotation mechanism, and then moves the disk rotation mechanism from the phase at which the maximum tilt angle is obtained when the tilt angle in one rotation period of the optical disk is distributed. An optical disk recording / reproducing apparatus, wherein chucking is performed again after rotating a predetermined angle.   When the tilt angle has a sinusoidal distribution with respect to one rotation period of the optical disk, the control means defines a position shifted by 90 degrees or 180 degrees from the phase at which the maximum tilt angle is obtained as the chucking phase. The optical disk recording / reproducing apparatus according to claim 1, wherein the disk rotating mechanism is rotated.

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