JP4028193B2 - Optical disk playback device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical disc reproducing apparatus capable of reproducing a signal written in a plurality of sessions on one disc, and in particular, an optical disc having a function of automatically adjusting an offset of a pickup servo system and a gain of an RF amplifier for each session. The present invention relates to a playback device.
[0002]
[Prior art]
Multi-session recording is standardized as one of recording methods for CD-R / RW discs. In this method, a combination of a lead-in area, a program area, and a lead-out area is set as one session, and a plurality of sessions are recorded on one disc. In each session, the lead-in area stores lead-in information such as TOC information that is track information in each session. The program area often stores information including user data and a path table from the previous session. In addition, recording is determined to record sessions in order from the inner periphery to the outer periphery of the disc.
[0003]
Therefore, in a CD-R drive, a CD-RW drive, or a dual-purpose drive (hereinafter collectively referred to as a CD-R / RW drive), when a disc is loaded, all disc information and the latest user information are stored. In order to obtain data information (pass table recorded in the last session), by reading the Q subcode information in the innermost lead-in area and determining that the disc is a multi-session recorded disc, A disk search is performed to search all the disk information up to the last session and the path table of the last session.
[0004]
The multi-session format of the CD-R / RW disc will be briefly described. As shown in FIG. 4, the recording area of the multi-session recorded CD-R / RW disc is composed of the PMA area, the first session, the second session, the third session,... Yes. Each time recording is interrupted in the PMA area, newly recorded disc information (track number (continuous number throughout all sections), start time, end time, etc.) is sequentially recorded after the previous disc information. The In the PMA area, currently valid disc information is written and recorded in order from the first track, and the information in the PMA area is erased entirely by quick erase. Therefore, all disc information of the currently valid section is recorded in the PMA area. In the case of packet writing, recording can be interrupted in the middle of a track. When recording is interrupted in the middle of a track, the track number and start time are recorded in the PMA area of the CD-RW disc for the track being recorded. Since the end time is still fixed, FF: FF: FF is recorded. When the track is completed, the determined end time is overwritten (overwritten). In the case of a CD-R disc, even if recording is interrupted in the middle of a track, the information is not recorded in the PMA area, and the disc information (track number, start time, end) is not recorded until the recording of the track is completed. Time etc.) is recorded.
[0005]
Each session includes a lead-in area (LI), a program area (PGM), and a lead-out area (LO) from the inner periphery side. In the lead-in area, a lead-in area including the TOC information of the session is recorded as pits. The TOC information includes information such as a start time and a lead-out start time for each track in the session. In addition, in the pre-group of the lead-in area, the start time of the lead-in area is recorded as ATIP special information. The start time of the PMA area is defined as 1000 frames before the start time of the lead-in area. The ATIP special information in the lead-in area records identification information indicating whether the disc is a CD-R disc or a CD-RW disc.
[0006]
The lead-in area of the first session is determined to be 23.25 mm from the center of the disk. The length of the lead-out area of the first session is defined as 01 minutes 30 seconds 00 frames (hereinafter referred to as 01:30:30). After the second session, the length of the lead-in area is defined as 01:00 and the length of the lead-out area is defined as 00:30.
[0007]
The Q subcode format of each lead-in area is shown in FIG. A lead-in area can be seen by TNO = 0. Multi-session recording can be recognized by the fact that ADR = 5 (mode 5) exists and TIME when POINT = B0 is a value other than FF: FF: FF. TIME (FF: FF: value other than FF) when ADR = 5 and POINT = B0 represents the start time of the program area of the next session. PTIME when POINT = 1.99 represents the start time of the track number represented by the POINT value. PMIN when POINT = A0 represents the last track number of the section. PTIME when POINT = A2 represents the start time of the lead-out area of the section.
[0008]
FIG. 6 shows the Q subcode format of the program area and lead-out area of each session. A program area or a lead-out area can be recognized by TNO ≠ 0. TNO in the program area represents the track number at that position. In the lead-out area, TNO = AA (h). INDEX = 0 is recorded as a pre-gap of the first track for the first 2 seconds from the start time of the program area. Immediately after that, an area of INDEX = 1 is recorded as user data. TIME indicates the relative time in the track, and TIME indicates the absolute time from the start time of the first session program area. The relative time TIME in the track is 0: 00 = 10: 00 when INDEX = 1, and gradually increases from there. When INDEX = 0, the final time is gradually decreased to 00:00.
[0009]
Recording on the CD-R / RW disc is performed by sequentially writing tracks in the program area from the inner circumference side to the outer circumference side. When recording of one session is completed, the session is established by recording lead-in and lead-out based on the track information recorded in the PMA of the session.
[0010]
As a method for searching all disc information (track number, start time, end time, etc.) up to the last session, there is a method of sequentially reading the lead-in area of each session. That is, first, the TOC information in the lead-in area of the first session is read, and the program start time information of the second session obtained at this time is used as a clue, and then the lead-in area of the second session is accessed. The TOC information is read, and the lead-in area of the third session is accessed by using the program start time information of the third section obtained at this time as a clue, and the TOC information of the third session is read. In this way, the lead-in area of each session is sequentially accessed. If there is no data in the lead-in area at the access destination, it is determined as an unrecorded part, and the session immediately before is determined as the last session. When all the disk information up to the last session is obtained, the last session path table and the like are continuously accessed based on the disk information of the last session and the last session path table and the like are obtained. It is possible to access each track only after obtaining these pieces of information.
[0011]
In a disk device such as a CD-R / RW drive, a laser beam emitted from an optical pickup is focused on the signal surface of the disk, a pit row or a magnetic domain row (hereinafter referred to as a track) is traced, and reflected from the signal surface. Data is read by detecting light with an optical pickup.
[0012]
The signal surface of the disk is constantly displaced due to surface runout during disk rotation, and the track is also constantly displaced due to core runout during disk rotation. For this reason, in a disk apparatus such as a CD-R / RW, the focus servo system and tracking are used in order to keep the laser beam focused on the signal surface and to track the track. It is equipped with a pickup servo system consisting of a servo system.
[0013]
Also, when the signal read by the pickup is amplified by the RF amplifier, the equalizer cutoff frequency adjustment, booth adjustment, and group delay adjustment are performed in the RF amplifier, so that the RF signal jitter and reproduction data error rate are the best. It is trying to become.
[0014]
In order to read the recorded signal from the disc without error, it is necessary to adjust the servo characteristics of the pickup servo to the optimum state. Conventionally, the manufacturer turns the semi-fixed resistor while playing the reference disc before shipping. I was adjusting. However, in order to cope with the time-dependent change of the servo characteristics due to the use of the apparatus or to cope with the individual disk that the user wants to listen to, it is desirable to perform the optimum adjustment every time the disk is played. Especially in an in-vehicle disc player, if the vibration is strong and the servo characteristics are poor, it will cause out-of-focus or out-of-tracking, resulting in frequent sound interruptions and skipping. It is. For this reason, the servo characteristic of the pickup servo system is automatically adjusted to the optimum value automatically when the disk is loaded and when the power of the disk reproducing apparatus is turned on. In addition, when a disc is loaded and when the disc player is turned on, the equalizer cutoff frequency, boost value, and group delay value in the RF amplifier are automatically adjusted to optimum values. .
[0015]
FIG. 7 is an overall configuration diagram of a conventional optical disk reproducing apparatus such as a CD having a pickup servo system automatic adjustment function. In the figure, 1 is a disk, 2 is a turntable, 3 is a spindle motor that rotates the disk at a constant linear velocity, 4 is a spindle servo circuit that performs constant linear velocity control on the spindle motor, and 5 is a laser beam emitted to the disk The optical pickup detects the reflected beam. The optical pickup 5 is provided with a four-divided photodiode 51, and D _A ~ D _D Consists of. D _A And D _C Are connected in parallel to output an (A + C) signal, and D _B And D _D Are connected in parallel to output a (B + D) signal.
[0016]
FIG. 8 is a diagram showing a focus servo error detection method. When in the in-focus state, as shown in FIG. _A ~ D _D When the beam spot is too far from the signal surface, as shown in FIG. _A And D _C D _B And D _D Less hits. When the beam spot is too close to the signal surface, as shown in FIG. _B And D _D D _A And D _C Less hits. Therefore, (A + C)-(B + D) indicates the error between the focal point of the beam spot and the signal surface.
[0017]
The optical pickup 5 is provided with a photodiode 5E that receives the reflected beam of the side beam spot A and outputs an E signal, and a photodiode 5F that receives the reflected beam of the side beam spot B and outputs an F signal. It has been. Note that the side beam spots A and B are positioned slightly shifted to the left and right before and after the main beam spot on the disk signal surface.
[0018]
FIG. 9 is a diagram showing a tracking error detection method by the three-spot method. As shown in FIG. 9A, when the main beam spot is directly above the recording track, the reflected light amount of the side beam spot A and the reflected light amount of the side beam spot B become the same level, and the output levels of the photodiodes 5E and 5F. Are the same. As shown in FIG. 9 (2), when the main beam spot is shifted to the right from the recording track, the reflected light amount from the side beam spot A becomes larger than the reflected light amount from the side beam spot B, and the output level of the photodiode 5E is It becomes larger than 5F. On the contrary, as shown in FIG. 9 (3), when the main beam spot is shifted to the left from the recording track, the amount of reflected light from the side beam spot B becomes larger than the amount of reflected light from the side beam spot A, and the photodiode 5E The output level is less than 5F. Therefore, (E−F) becomes zero when the main beam spot is directly above the recording track, becomes + when it shifts to the right from the recording track, and the absolute value increases in proportion to the shift amount. In addition, when it shifts to the left from the recording track, it becomes-and the absolute value increases in proportion to the shift amount, so that (EF) indicates an error between the main beam spot and the recording track.
[0019]
Returning to FIG. 7, 6 is a sled motor that sends the optical pickup in the radial direction of the disk, 7 is a sled servo circuit that applies sled servo for tracking the track to the sled motor, and 8 is an RF amplifier. The RF amplifier 8 is configured as shown in FIG. 10. Of these, 8a and 8b are current-voltage converters (I) for individually converting current-voltage signals (A + C) and (B + D) input from an optical pickup. -V), 8c and 8d are current-voltage converters (IV) for individually converting the E signal and F signal input from the optical pickup into current-voltage converters, and 8e is the output of the current-voltage converters 8a and 8b. It is an adder that adds up to create an RF signal. Returning to FIG. 7, reference numeral 9 denotes a digital signal processing circuit which inputs an RF signal and demodulates music data and subcode data.
[0020]
A focus servo circuit 10 generates a focus error signal FE from the (A + C) signal and the (B + D) signal, drives a focus actuator (not shown) provided in the optical pickup 5 based on the focus error signal FE, and applies focus servo. It is configured as shown in FIG. 10a is a variable gain amplifier provided on the output side of the current-voltage converter 8a, 10b is a variable gain amplifier provided on the output side of the current-voltage converter 8b, and 10c is a variable gain amplifier from the output of the variable gain amplifier 10a. A subtractor for subtracting the output of 10b to create a focus error signal FE, and 10d is an A / D converter for analog / digital conversion of the output of the subtractor 10c. The output of the A / D converter 10d is input to a servo controller 16 described later. 10e is a subtractor that subtracts the output of the A / D converter 10d and the offset value given from the servo controller 16, and 10f is a loop that performs boosting of the low frequency gain of the output of the subtractor 10e and phase compensation of the high frequency. Filters 10g are variable gain amplifiers that amplify the output of the loop filter 10f. The gain of the variable gain amplifier 10g changes in accordance with a signal from the servo controller 16. Reference numeral 10h denotes a switch having one end connected to the output end of the amplifier 10g and turned on / off by a signal from the servo controller 16. An adder 10j is connected to the other end of the switch 10h, and an input terminal of the adder 10j is connected to the servo controller 16. Reference numeral 10i denotes a variable frequency oscillator that oscillates in response to a signal from the servo controller 16, and the output of the variable frequency oscillator 10i is connected to an adder 10j. Reference numeral 10k denotes a D / A converter that performs digital / analog conversion on the output of the adder 10j. The output of the D / A converter 10k is given to a servo driver 11 described later. Returning to FIG. 7, reference numeral 11 denotes a servo driver that amplifies the focus error signal FE and drives the focus actuator.
[0021]
A tracking servo circuit 12 generates a tracking error signal TE from the E signal and the F signal, drives a tracking actuator (not shown) provided in the optical pickup 5 based on the tracking error signal TE, and applies a tracking servo. The configuration is as shown in FIG. 12a is a variable gain amplifier provided on the output side of the current-voltage converter 8c, 12b is a variable gain amplifier provided on the output side of the current-voltage converter 8d, and 12c is a variable gain amplifier from the output of the variable gain amplifier 12a. A subtractor that subtracts the output of 12b to create a tracking error signal TE, and 12d is an A / D converter that performs analog / digital conversion on the output of the subtractor 12c. The output of the A / D converter 12d is input to a servo controller 16 described later. 12e is a subtractor that subtracts the output of the A / D converter 12d and the offset value supplied from the servo controller 16, and 12f is a loop that performs boosting of the low frequency gain of the output of the subtractor 12e and phase compensation of the high frequency. A filter 12g is a variable gain amplifier that amplifies the output of the loop filter 12f. The gain of the variable gain amplifier 12g changes according to the signal from the servo controller 16. A switch 12 h is connected at one end to the output terminal of the amplifier 12 g and is turned on / off by a signal from the servo controller 16. An adder 12j is connected to the other end of the switch 12h, and an input end of the adder 12j is connected to the servo controller 16. Reference numeral 12i denotes a variable frequency oscillator that oscillates in response to a signal from the servo controller 16, and the output of the variable frequency oscillator 12i is connected to an adder 12j. 12k is a D / A converter for digital / analog converting the output of the adder 12j. Returning to FIG. 7, reference numeral 13 denotes a servo driver that amplifies the input from the D / A converter 12k and drives the tracking actuator.
[0022]
14 is a detection circuit for detecting the lower envelope of the RF signal, 16 is a servo controller for starting up various servos and automatically adjusting the pickup servo system in response to a command from a system controller to be described later, and 17 is for inserting a disk. A disc insertion detector 18 to detect, a loading unit 18 for loading or unloading the disc 1 on the turntable 2 according to the control of the system controller, and 19 a system necessary for reproducing the disc A system controller that performs overall control, 20 is a RAM that stores TOC information, and 21 is an operation unit that performs various operations.
[0023]
FIG. 13 is a diagram showing an operation flow at the time of starting the conventional disk reproduction.
When the insertion of the disk 1 is detected by the disk insertion detector 17, the system controller 19 controls the loading unit 18 to start loading the disk 1 onto the turntable 2 (Step 101, Step 102). When the loading is completed, the loading unit 18 sends a loading completion notice to the system controller 19, and the system controller 19 that received the notice (YES in step 103) gives a servo-on / automatic adjustment command to the servo controller 16. Upon receiving this command, the servo controller 16 starts up various servos while automatically adjusting the pickup system in the following order (a) to (m).
[0024]
(A) Focus offset adjustment (step 104)
With the laser of the optical pickup 5 turned off, the output of the subtracter 10c is read to determine the focus offset amount. The focus offset is zero when the current-voltage converters 8a and 8b, the variable gain amplifiers 10a and 10b, and the subtractor 10c are in a balanced state, but does not become zero when they are not in a balanced state. The servo controller 16 outputs the obtained focus offset amount as an argument to the subtractor 10e.
[0025]
(B) Tracking offset adjustment (step 105)
With the laser of the optical pickup 5 turned off, the output of the subtracter 12c is read to obtain the tracking offset amount. The tracking offset is zero when the current-voltage converters 8c and 8d, the variable gain amplifiers 12a and 12b, and the subtractor 12c are in a balanced state, but not zero when they are not in a balanced state. The servo controller 16 outputs the obtained tracking offset amount as an argument to the subtractor 12e.
[0026]
(C) Focus gain rough adjustment (step 106)
The laser of the optical pickup 5 is turned on, and the low frequency triangular wave is output from the variable frequency oscillator 10i with the loop switch 10h opened. Since the focus error signal FE draws an S-curve as shown in FIG. 14 (1), P-P (V (FE) in FIG. _PP Reference) is read, and the gain of the variable gain amplifier 10g is adjusted so that this becomes a predetermined reference value.
[0027]
(D) Focus servo on (step 107)
After the focus gain adjustment, the change in the focus error signal FE is monitored from the output of the subtractor 10c while the low-frequency triangular wave is output from the variable frequency oscillator 10i, and the timing when it becomes near zero cross (A in FIG. 14 (1)). Point), the loop switch 10h is closed and the focus servo is turned on. Thereafter, the oscillation of the variable frequency oscillator 10i is stopped.
[0028]
(E) Spindle motor activation (step 108)
A starting voltage is applied to the spindle servo circuit 4 to start the spindle motor 3 and start the rotation of the disk 1.
[0029]
(F) Tracking servo ON (step 109)
When the disk 1 rotates, the lower envelope of the RF signal periodically changes each time the laser beam crosses the track. Therefore, the servo controller 16 monitors the lower envelope of the RF signal that is the output of the detection circuit 14. The loop switch 12h is closed at the timing when the tracking servo enters the negative feedback region, and the tracking servo is turned on.
[0030]
(G) Weight, spindle servo and thread servo on (steps 110 to 112)
After waiting for several hundreds of milliseconds until the disk 1 reaches a specified rotational speed, the spindle servo is turned on, and then the sled servo is turned on.
[0031]
(H) Tracking gain rough adjustment (step 113)
Open the loop switch 12h and turn off the tracking servo. At this time, the tracking error signal TE periodically changes as shown in FIG. 14 (2) every time it crosses the track. Therefore, the change of the tracking error signal TE is read from the subtractor 12c, and P-P (FIG. 14 (2)). V (TE) _PP The gain of the variable amplifier 12g is adjusted so that the reference value becomes a predetermined reference value.
[0032]
(I) Tracking balance adjustment (step 114)
While the tracking servo is off, the change in the tracking error signal TE is read from the subtractor 12c, and the upper peak level and the lower peak level (V in FIG. 14 (2)) are read based on the tracking offset obtained in (b). ₁ And V ₂ The gains of the variable gain amplifiers 12a and 12b are adjusted so that the reference) matches.
[0033]
(J) Focus balance adjustment (step 115)
The tracking servo is turned on and a sine wave disturbance of several hundred Hz is injected into the focus servo system from the variable frequency oscillator 10i. At this time, the lower envelope of the RF signal periodically changes as shown in FIG. 14 (3). ₃ And V ₄ The gains of the variable gain amplifiers 10a and 10b are adjusted so as to match. Thereafter, the oscillation of the variable frequency oscillator 10i is stopped.
[0034]
(K) Focus gain fine adjustment (step 116)
Of the open loop gain characteristics of the focus servo system, the cross frequency f _c Is injected into the focus servo system from the variable frequency oscillator 10i, the one-round disturbance component is read from the output of the variable gain amplifier 10g, and the level ratio of the one-round disturbance component is the desired closed-loop gain characteristic. The gain of the variable gain amplifier 10g is adjusted so as to be a predetermined gain value. After the adjustment, the oscillation of the variable frequency oscillator 10i is stopped.
[0035]
(M) Fine adjustment of tracking gain (step 117)
Of the open loop gain characteristics of the tracking servo system, the cross frequency f _c Is injected into the tracking servo system from the variable frequency oscillator 12i, the looped disturbance component is read from the output of the variable gain amplifier 12g, and the level ratio of the looped disturbance component is the desired closed loop gain characteristic. The gain of the variable gain amplifier 12g is adjusted so as to be a predetermined gain value. After the adjustment, the oscillation of the variable frequency oscillator 10i is stopped.
[0036]
Thus, after the adjustment of the servo system of the pickup is completed, the equalizer of the RF amplifier is adjusted (step 118). The equalizer adjustment of the RF amplifier is performed according to the following procedure.
(1) Search for the best cut-off frequency
The cutoff frequency value that minimizes the jitter amount is searched while changing the cutoff frequency FC value of the RF amplifier.
(2) Setting the best cutoff frequency
The cutoff frequency FC value determined in process (1) is set.
(3) Search for the best boost value
The boost value that minimizes the jitter amount is searched while changing the boost value of the RF amplifier.
(4) Boost best value setting
The boost value determined in process (3) is set.
(5) Search for the best cut-off frequency
The cutoff frequency value that minimizes the jitter amount is searched while changing the cutoff frequency FC value of the RF amplifier.
(6) Setting the best cutoff frequency
The cutoff frequency FC value determined in the process (5) is set.
(7) Find the best value of group delay
The group delay value that minimizes the jitter amount is searched and set while changing the group delay value of the RF amplifier.
[0037]
Thus, after the servo adjustment from the focus offset adjustment to the tracking gain adjustment and the equalizer adjustment of the RF amplifier are completed, the lead-in area on the innermost circumference of the disk is accessed and the TOC information of the first session is read (step 119). ). Thereafter, the TOC information read in step 119 is stored in the RAM 20 (step 120).
[0038]
Next, the program start time information of the next session obtained from the read TOC information is used as a clue to access the lead-in area of the next session, and it is determined whether there is data in the lead-in area at the accessed destination. (Step 121). That is, it is determined whether there is a next session.
[0039]
If there is a next session, return to step 119 and read the TOC information of that session. Until there is no next session, the processing from step 119 to step 121 is continued. On the other hand, if there is no next session, the automatic adjustment process is terminated. Thereafter, referring to the TOC information stored in the RAM 20, the head of one track is searched and reproduction is started.
[0040]
[Problems to be solved by the invention]
By the way, when a multi-session disc is reproduced, reproduction after the second session is performed using various servo adjustment values in the first session located on the inner circumference of the disc when the disc is inserted or when the apparatus is turned on. The write-once disc may be recorded by a different device for each session, or the pit formation state may be different for each session even for the same disc due to a difference in writing speed at the time of recording.
[0041]
If the session after the second session is played back using the adjustment value adjusted in the first session as in the past, data cannot be read due to the difference in the recording state (difference in the pit formation state) It was difficult.
[0042]
As described above, an object of the present invention is to provide an optical disc reproducing apparatus that performs reproduction using an optimum adjustment value for each session at the time of reproduction of a multi-session disc and enables stable reproduction.
[0043]
[Means for Solving the Problems]
According to the present invention, there is provided a disc discriminating means for discriminating whether or not a disc is a multi-session disc in an optical disc reproducing apparatus capable of reproducing a multi-session disc in which a plurality of sessions are recorded on one disc. An automatic adjustment means for performing various adjustments of the disk drive, and an adjustment for performing automatic adjustment for each session by the automatic adjustment means and storing the adjustment value for each session when the disk discrimination means discriminates the multi-session disc This is achieved by an optical disk reproducing apparatus comprising value storage means and control means for reading an adjustment value corresponding to a session to be reproduced from the storage unit and controlling the disk drive based on the adjustment value during disk reproduction.
[0044]
Further, according to the present invention, the above-described problem is achieved by an optical disc reproducing apparatus in which the items adjusted by the automatic adjustment means are adjustment values of a pickup servo system.
[0045]
Further, according to the present invention, the above-described problem is achieved by an optical disc reproducing apparatus in which the item adjusted by the automatic adjustment means is an adjustment value of an equalizer of an RF amplifier.
[0046]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram showing a configuration of an optical disk reproducing apparatus according to the present invention. A difference from the conventional reproducing apparatus is that a RAM 30 for storing servo system adjustment values for each session is connected to the system controller 19 and added. The same reference numerals as those in the prior art are the same as those in the conventional reproducing apparatus.
[0047]
FIG. 2 is a diagram showing an operation flow at the time of activation of the optical disk reproducing apparatus of the present invention.
As in the prior art, when the insertion of the disk 1 is detected by the disk insertion detector, the system controller 19 controls the loading unit 18 to start loading the disk 1 onto the turntable 2 (step 201, step 202). ).
[0048]
When the loading is completed, the loading unit 18 sends a loading completion notice to the system controller 19, and the system controller 19 that has received the notice (YES in step 203) removes the pickup from the innermost lead-in area (that is, the first area). The position is moved to a readable position in the session lead-in area) and a servo-on / automatic adjustment command is given to the servo controller 16. Upon receiving this command, the servo controller 16 performs automatic adjustment processing (automatic adjustment of the pickup servo system, automatic adjustment of the equalizer of the RF amplifier) described in the prior art (step 204).
[0049]
Next, the TOC information recorded in the lead-in area on the innermost circumference side of the disc is read (step 205). That is, the lead-in area of the first session is accessed and the TOC information of the first session is read.
[0050]
When reading of the TOC information of the session is completed, the next session's lead-in area is accessed using the program start time information of the next session obtained at this time, and whether there is data in the lead-in area at the accessed destination. (Step 206). That is, it is determined whether there is a next session.
[0051]
If there is a next session, various adjustment values automatically adjusted in step 204 are stored in the RAM 30 together with the corresponding session number (step 207), the pickup 5 is moved to the next session (step 208), and step 204 is performed. Return to and perform automatic adjustment processing in the next session. If there is no next session in step 206, the disk activation process is terminated. As described above, automatic adjustment processing is performed for each session when the disk is started, and adjustment values for each session are stored in the RAM 30.
[0052]
At the time of disc reproduction, the adjustment value corresponding to the session to be reproduced is read from the RAM 30 and set. Further, even when the session to be reproduced changes, the adjustment value corresponding to the session to be reproduced is read from the RAM 30 and set.
[0053]
FIG. 3 shows an operation flow for setting an adjustment value in accordance with a section during disk reproduction. Here, the description will be made assuming that the adjustment value for each session is already stored in the RAM 30.
[0054]
First, the target address is calculated (step S301), and it is determined whether or not the corresponding address is a session different from the current session, that is, whether or not the session for reading data has changed from the current session (step S301). 302).
[0055]
If there is a session change in step 302, various adjustment values for the target section are read from the RAM 30, and the pickup servo system and RF amplifier are set (step 303).
[0056]
Thereafter, a seek operation to the target address is performed (step 304), and the address is read (step 305). If the read address is the target address, the seek operation is completed. If the read address is not the target address, the process returns to step S301 to repeat the process (step 306).
[0057]
In this way, when playing back a multi-session disc, playback can be performed using an adjustment value suitable for each session to be played back.
[0058]
In the description of the above embodiment, the CD-R has been described as an example. However, the present invention can be applied to an optical disc such as a CD-RW, a DVD-R, and a DVD-RW.
[0059]
Further, in the description of the above embodiment, it has been described that all adjustments are made for each session when the disk is started. However, all adjustments are made only for the first session, and for the sessions after the second session, Only a part of the adjustment may be performed, and the adjustment value may be stored in the RAM 30 for each session. In this case, at the time of reproduction for the second and subsequent sessions, the adjustment value for each session stored in the RAM 30 and the adjustment value that is not stored may be reproduced using the adjustment value stored in the first session. Good.
[0060]
The present invention has been described with reference to the embodiments. However, the present invention can be variously modified in accordance with the gist of the present invention described in the claims, and the present invention does not exclude these.
[0061]
【The invention's effect】
As described above, according to the present invention, automatic adjustment is performed for each session at the time of starting the disc, the adjustment value is stored in association with each session, and at the time of disc playback, playback is performed using the adjustment value corresponding to the session to be played back. Thus, stable data reading can be performed, and playability can be improved.
[0062]
Further, according to the present invention, since the adjustment value that is automatically adjusted at the time of starting the disk and stored in association with each session is the adjustment value of the pickup servo system, the session to be reproduced when each session is reproduced Servo characteristics suitable for the recording state can be obtained, and stable disk reproduction can be performed.
[0063]
Further, according to the present invention, automatic adjustment is performed at the time of starting the disk, and the adjustment value stored in association with each session is set as the adjustment value of the equalizer of the RF amplifier. Therefore, the reproduction is performed when each session is reproduced. The equalizer characteristics of the RF amplifier suitable for the recording state of the session can be obtained, and stable disc reproduction can be performed.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an optical disk reproducing apparatus according to the present invention.
FIG. 2 is a diagram showing an operation flow at the time of starting the disc of the optical disc reproducing apparatus of the present invention.
FIG. 3 is a diagram showing an operation flow for setting an adjustment value according to a section during disk playback of the optical disk playback apparatus of the present invention.
FIG. 4 is an explanatory diagram of a multi-session format of a CD-R / RW disc.
FIG. 5 is an explanatory diagram of a Q subcode format of each lead-in area.
FIG. 6 is an explanatory diagram of a Q subcode format of a program area and a lead-out area of each session.
FIG. 7 is a diagram showing a configuration of a conventional optical disc playback apparatus.
FIG. 8 is a diagram showing a focus servo error detection method.
FIG. 9 is a diagram illustrating a tracking error detection method.
FIG. 10 is a diagram illustrating a configuration of an RF amplifier.
FIG. 11 is a diagram illustrating a configuration of a focus servo circuit.
FIG. 12 is a diagram showing a configuration of a tracking servo circuit.
FIG. 13 is a diagram showing an operation flow at the time of conventional disc playback start-up.
FIG. 14 is a wave diagram illustrating an automatic adjustment method.
[Explanation of symbols]
1. Disk
5. Pickup
8. RF amplifier
10. Focus servo circuit
12. Tracking servo circuit
16. Servo controller
19. System controller
20, 30 ... RAM

Claims (3)

In an optical disc reproducing apparatus capable of reproducing a multi-session disc in which a plurality of sessions are recorded on one disc,
Disk discriminating means for discriminating whether or not the disc is a multi-session disc;
Automatic adjustment means for performing various adjustments of the disk drive;
When disc discriminating means is discriminated as a multi-session disc,
Automatic adjustment for each session by the automatic adjustment means, adjustment value storage means for storing an adjustment value for each session,
An optical disk reproducing apparatus comprising: control means for reading an adjustment value corresponding to a session to be reproduced from the storage unit during disk reproduction, and controlling the disk drive based on the adjustment value. 2. The optical disk reproducing apparatus according to claim 1, wherein the item to be adjusted by the automatic adjustment means is an adjustment value of a pickup servo system. 2. The optical disk reproducing apparatus according to claim 1, wherein the item to be adjusted by the automatic adjustment means is an adjustment value of an equalizer of an RF amplifier.

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