JP2981031B2 - Read-write optical disk reproducing method and optical disk reproducing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a write-once optical disc reproducing method and an optical disc reproducing apparatus, and more particularly to a reproducing method and a reproducing apparatus suitable for reproducing recorded information from a write-once optical disc during recording.

[0002]

2. Description of the Related Art Conventionally, an optical disk having a diameter of 12 cm or 8 cm called a compact disk (CD) is known. As shown in FIG. 6, the CD has a lead-in area, a program area, and a lead-out area formed from the inner periphery of the disc. The signal to be recorded is a digital signal modulated by EFM (Eight to Fourteen Modulation), and includes a subcode such as a time code (Q data) representing time information in addition to a main code which is main information such as music information. Have been. EFM
The signal includes a clock signal. The clock signal is compared with a reference synchronization signal, and the amount to be corrected is fed back to the spindle motor via an error amplifier, a spindle drive amplifier, etc., to control the rotation speed of the spindle motor. be able to. This is spindle servo control.

The lead-in area has a TOC (Table of C
index information called ontents) is recorded. In the TOC, the total number of music pieces, the total playing time, and the like recorded in the program area of the disc are recorded as subcodes. In the program area, as shown in FIG. 7, music information and the like are recorded as a main code, Q data of a subcode, a track number (TNO) indicating a song number, and a relative playing time from the start of the track. (P-TIME),
The absolute total performance time (A-TIME) measured from the track number 1 is recorded. In the lead-out area, a lead-out code indicating the lead-out area is recorded.

A CD having such a recording format
Is a read-only medium, but in recent years, a write-once compact disc (R-CD: Recordable Compa
ct Disk) was developed. The recording format of this R-CD is generally called "Orange Book" and conforms to the CD format. However, as shown in FIG.
CA (Power Calibration Area) area and PMA (Progra
m Memory Area) area is provided. These PCAs
The area and the PMA area will be described later.

On the other hand, a guide groove is formed in a recording track of the R-CD, and the guide groove transmits a carrier (carrier) of 22.05 KHz to data (ATI) indicating absolute time information.
P: Absolute Time In Pregroove (wobbling). A laser beam (recording beam) for recording information is track-controlled along the guide groove, and the number of rotations of the spindle motor is controlled so that the center frequency of wobbling becomes 22.05 KHz. , It is possible to perform tracking servo and spindle servo.

[0006] The ATIP information is composed of 42 bits per frame. After a 4-bit sync pattern SYNC, 8 bits each representing "minute (MIN)", "second (SEC)" and "frame (FRAME)" are provided. And the 14-bit error correction code ECC. ATI
The absolute time information indicated by the P information is 1 second in 75 frames, similarly to the Q data of the subcode.

Further, in the ATIP information, special information is encoded by a combination of the first one bit (MSB) of data indicating "minute", "second", and "frame" in addition to normal absolute time information. In particular, when the combination of the bits is "1", "0", or "1", the three bits of the sixth to eighth bits represent the recommended recording power (light intensity) for the disc. That is, "000" ~
Eight levels of recommended recording power are determined corresponding to eight combinations of each bit of “111”. The recommended recording power is based on the condition that the wavelength of the recording beam is λ = 780 nm (nanometers) and the temperature T is 25 ° C. However, in practice, the wavelength λ has temperature dependence and the aperture ratio of the objective lens. The optimum recording power (light intensity) does not always coincide with the recommended recording power due to a difference in NA or the like.

The PCA area is an area where test recording is performed prior to a recording operation in order to make the laser power at the time of recording appropriate, and is formed by a count area and a test area. In each area of the count area having a plurality of areas, an appropriate EFM signal is recorded in one-to-one correspondence with the area used in the test area. Prior to the recording operation, test recording for measuring the optimum recording power is performed in each area of the test area. This is because, as described above, the recommended recording power in the ATIP information does not always match the optimum recording power. One test recording consumes one of the subdivided areas of the test area.

The test area once recorded in the test area cannot be used in the next test recording. Therefore, it is necessary to search for an unused area located on the inner peripheral side of the disc. A count area is provided to facilitate the operation. That is, for example, an appropriate EFM signal is recorded up to a certain area of the count area, and if an adjacent area is in an unrecorded state, the corresponding test area area is a test recordable area. Is shown. Therefore, the optimum recording power may be measured by searching for the unrecorded test area and performing test recording. When the measurement of the optimum recording power in the test area is completed, the area of the count area corresponding to the area is searched, and appropriate information (EFM signal) indicating that the test has been completed is recorded. .

The PMA area is an area for storing the record history of the record information sequentially recorded in the program area. The start address and end address of each track number recorded in the program area are used as the TOC information in the lead-in area. It is recorded in a similar format.

This is a partially recorded disc (Partia
lly recorded Disk), information may be continuously added to the remaining program area. Therefore, information in the PMA (hereinafter referred to as “temporary TOC”) is lead-in until recording completion is finally instructed. This is because it cannot be recorded in the area. For this reason, it is necessary to temporarily record only information of each recorded track.
On the other hand, when a recording completion instruction not to perform further recording is given by a user's instruction or a command from a system controller or the like, the TOC information and the lead-out signal are respectively recorded for the first time. In this case, the TOC information of the PMA for which recording has been completed is transferred to the lead-in area a plurality of times in order to ensure reliability. An R-CD (Finalized Disk) for which recording has been finally completed in this way
Is compatible with the CD format.
It is possible to reproduce even a normal reproduction-only CD player having no ATIP decoder or the like for decoding IP information. FIG. 9 shows a recording state in the R-CD. FIG. 9A shows an unrecorded disk (virgin disk)
FIG. 9 (B) shows a partially recorded disc, and FIG. 9 (C)
Indicates disks on which recording has been completed.

[0012]

However, as described above, in a partially recorded R-CD, no information is recorded in the lead-in area. In this case, since the EFM signal cannot be obtained even if the spindle motor is accelerated and rotated, the spindle servo is not locked (converged), and there is a danger that the spindle motor will run out of control and the rotation speed of the spindle motor will become abnormally high or reverse. Further, it is impossible to detect the wobbling frequency and perform the spindle servo because the conventional read-only CD player has no means for detecting wobbling. Furthermore, the provisional TOC in the PMA area
There is a case where the optical pickup is a disc player having a structure in which the optical pickup cannot be transported to the PMA area even when trying to read the data.

Therefore, the present invention provides a partially recorded R-C by utilizing the function of a conventional read-only disc player as much as possible.
It is an object of the present invention to provide a reproducing method and a reproducing apparatus capable of reproducing D.

[0014]

According to a first aspect of the present invention, there is provided an information recording area in which a plurality of information pieces can be recorded, and recording of the information recording area in all areas is completed. And an index area for recording index information for information search in the case where the information is recorded. The write-once optical disc is rotated while rotating the write-once optical disc. A step of detecting whether or not index information is recorded in the index area without rotating the write-once optical disc; and a step of detecting the index in the first step. When it is detected that the index information is not recorded in the area, the first information piece among the information pieces recorded in the information recording area is rotated without rotating the write-once optical disc. A second step of transferring the pickup means to the leading information piece while searching, and, when the pickup means reaches the leading information piece, rotating the write-once optical disc and recording the recorded information by the pickup means. A third step of reading and reproducing the recorded information only in a portion where the recorded information is recorded while detecting whether or not the recorded information is present.

According to a second aspect of the present invention, there is provided an information recording area in which a plurality of information pieces can be recorded, and an index area for recording index information for information retrieval when recording in all areas of the information recording area is completed. An optical disc reproducing apparatus capable of reproducing the recorded information from the write-once optical disc, comprising: a rotating means for rotating the write-once optical disc; and irradiating the write-once optical disc with a light beam to read information. Pickup means, transfer means capable of transferring the pickup means to any position in the radial direction of the write-once optical disc,
Control means for controlling the rotation means, the pickup means, and the transfer means, and the control means detects whether or not index information is recorded in the index area without rotating the write-once optical disc. If it is detected that the index information is not recorded in the index area, the first information piece among the information pieces recorded in the information recording area is rotated by the rotating means to rotate the write-once optical disc. The search means is moved to the leading information piece while searching, and if the pickup means reaches the leading information piece, it is determined whether or not the recording information is present by the pickup means. It is configured to read and reproduce the recorded information only in a portion where the recorded information is recorded while detecting.

[0016]

According to the write-once optical disc reproducing method and the optical disc reproducing apparatus having the above-described configuration, the write-once optical disc is rotated by determining whether or not index information (for example, TOC) is recorded in an index area (for example, a lead-in area). If it is detected that the index information has not been recorded, the information piece at the head of the information recording area (for example, the program area) is searched without rotating the write-once optical disc. The desired recorded information is read and reproduced from the information piece. During reproduction, reading and reproduction are performed only in the portion where the recording information is recorded, while detecting whether or not the recording information exists. Therefore, there is no danger that the rotating means (for example, a spindle motor) will become uncontrollable, and the reproduction can be performed by simple control.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of one embodiment of the present invention.
As shown in FIG. 1, the disc player comprises an optical pickup 2, a sled mechanism 3, a reproducing amplifier 4, a peak hold circuit P, an EFM demodulator 5, and a servo circuit 7.
And 14, a low-pass filter 8, a spindle motor 9, a system controller 10, an oscillation circuit 11,
Changeover switch _{SW 1, SW 2, SW 3} , SW 4, SW 5
And is provided.

Next, a normal CD reproducing operation in the disc player will be described. Information recorded on the disk 1 is read by the main body 21 of the optical pickup 2. The optical pickup 2 supports an objective lens 22 for focusing a laser beam on the disk 1. The objective lens 22 can be driven in an optical axis direction (focus direction) and a disk radial direction (tracking direction) by an actuator 23. It is configured. The optical pickup 2 itself is configured to be movable in the disk radial direction by a thread mechanism 3.

The data is read from the main body 21 of the optical pickup.
The signal (read RF signal) is sent to the EFM
Supply to the controller 5 and a coupling capacitor C₁To
More AC coupled and diode D₁and
Capacitor C_TwoThe peak hold circuit P
A voltage corresponding to the RF signal level is generated, which is
It is supplied to one input terminal of the parator 6. Comparing
A predetermined threshold level is applied to the other input terminal of the
Voltage V_thIs supplied, and as a result, the comparator 6
The output of “H” or “L” depends on the presence or absence of the RF signal.
RF detection signal D _RFIs detected. The output of the EFM demodulator 5 is
It is supplied to the servo circuit 14.

Further, a focus error signal FE and a tracking error signal TE are generated by the servo circuit 7, and the error signals FE and TE are respectively switched by a changeover switch S
The signals are supplied to the actuator 23 via W ₁ and SW ₂ to form a focus servo loop and a tracking servo group. Further, a low-pass component of the tracking error signal TE is extracted by the low-pass filter 8, and a thread error signal SLE for moving the optical pickup 2 along the thread mechanism 3 is generated.
Sled error signal SLE is sled servo loop is supplied to the thread mechanism 3 via the switch SW ₃ is formed. Further, from the servo circuit 14, for example, the reproduction E
The spindle error signal SPE is generated by detecting the phase difference between the reproduction clock extracted from the FM signal and the reference clock. The spindle error signal SPE is switched by the changeover switch S
It is supplied to the spindle motor 9 through the W _4. The reproduced clock is generated by a PLL (Phase Locked Loop) circuit (not shown) of the servo circuit 14.
PLL lock detection signal D _PL indicating the locked state of the circuit is supplied to the system controller 10. The switching of these switches SW _{1 to} SW ₄ is controlled by the system controller 10.

Each of the changeover switches is connected to a drive signal source for not only turning on / off the servo loop but also forcibly driving a driven portion driven and controlled by the servo loop. For example, in order to cause the actuator 23 to jump in the radial direction of the disk in the tracking servo loop, the FWD having a polarity corresponding to the direction
(Forward) voltage, REV (the reverse direction) the movable contact of the voltage selector switch SW _2, the polarity of the FWD voltage corresponding to the direction for which high-speed movement of the optical pickup in a disk radial direction in the sled servo loop, the REV voltage the movable contact of the switch SW _3, F for the spindle motor acceleration, decelerates the spindle servo loop
WD voltage, REV voltage is configured to be supplied to the movable contact of the changeover switch SW _4. The DC level generated by each drive signal source is controlled by the system controller 10. For example, if the voltage levels of the FWD and REV signals given to the sled mechanism 3 are changed, the moving speed of the optical pickup 2 can be made variable.

Next, the operation of reproducing a partially recorded R-CD in the disc player will be described with reference to FIGS. As shown in FIG. 2, first, the optical pickup 2 is transferred to the position of the lead-in area of the disk 1 by the sled mechanism 3 with the spindle motor 9 stopped (step S1). In a normal CD, the lead-in area is set in a range of 23 mm to 25 mm from the center of the disc. Therefore, the above operation can be performed by providing a sensor switch (not shown) at the innermost peripheral position of the lead-in area and transferring the optical pickup 2 by the sled mechanism 3 until the optical pickup 2 reaches the sensor switch. it can.

Next, the focus servo is turned on, and it is determined whether or not locking (convergence) has been achieved (step S2). Retraction of the focus servo is performed using means described in Japanese Patent Publication No. 63-13261, etc., and when the retraction operation is not completed within a predetermined time or when it is not completed within a predetermined number of retries (retry), etc. Is determined to be focus unlocked (non-convergence), and in this case, it is determined that there is no disk (step S3).

[0024] When the retraction of the focus servo is completed, remains in a state where the spindle motor 9 is stopped, the switch SW ₅ is closed (ON) (Step 4). Change-over switch SW ₅ is the system controller 10
The switching is controlled by. When the switch SW ₅ to ON, the output of the oscillation circuit 11 is mixed into the tracking servo loop. The oscillation circuit 11 is an oscillation circuit that oscillates at a single frequency. Therefore, the tracking servo loop and OFF (i.e., the changeover switch SW ₂ OF
F), since the oscillation output of the oscillation circuit 11 to the switch SW ₅ If ON when the tracking servo loop is supplied, the actuator 23 of the optical pickup 2 vibrates in the tracking direction (disk radial direction) at the frequency of the oscillation output. By setting the amplitude of the oscillation output at this time to an appropriate level, the information reading beam is driven to cross a plurality of tracks on the disk 1. Generally, the driving range of the tracking actuator is several hundred μm, and if the track pitch is 1.6 μm, it will cross 100 or more tracks.

Next, the waveform of the read RF signal reproduced by the optical pickup 2 when the information reading beam crosses the track as described above will be described. First, when the actuator is oscillated in the tracking direction in an unrecorded portion so as to cross a plurality of recording tracks, R-C
Depending on the presence or absence of the guide groove formed in the D disk, the read R
The strength of the F signal waveform appears. This is called radial contrast (contrast in the disk radial direction). The amplitude of the radial contrast is determined by the depth of the guide groove, the wavelength of the beam, and the track pitch, but is generally at an extremely small level. Accordingly, the output level peak-held by the peak hold circuit P also becomes an extremely small level, and the comparator 6 outputs “L” as the RF detection signal.

On the other hand, when the actuator is oscillated in the tracking direction in the recorded portion, the pits recorded on the traversed track cause the laser beam to be diffracted, thereby causing the light intensity of the reflected beam to be bright and dark. An RF signal is obtained at the time of normal reproduction by utilizing the principle that the reflected beam is bright and dark due to the phenomenon that the laser beam is diffracted by pits existing in the track tangential direction. In other words, even if the beam is moved in the radial direction of the disk), there are pits in the crossing tracks, so although the frequency band is different,
A similar amount of light and dark occurs. Since this difference in brightness appears as the amplitude of the read RF signal, the output level peak-held by the peak hold circuit P becomes a large level, and the comparator 6 outputs “H” as the RF detection signal.

FIG. 5 shows the waveform of the RF signal. At time t ₁ , the focus servo is pulled in, and from time t _{2, the} thread servo starts to be transferred in the FWD direction while oscillating the actuator. Toward the t ₃ from the time t _2, the shows the RF signal in the lead-in area of the disc, the waveform of small amplitude is obtained by radial contrast. Next, when at time t ₃ into the recorded program area, the amplitude of the RF signal increases by brightness of the diffraction effect of each track pit. Again if at time t ₄ reaches the unrecorded area becomes a small amplitude of the waveform due to radial contrast.
The time t ₅ is a time when allowed stopping the vibration of the actuator.

The RF signal which varies in this manner, since the DC component is removed by AC coupling by the capacitor C _1, the peak hold circuit P eventually to hold the peak value from the central value of the amplitude of the RF signal Become. Then, the hold voltage is compared with an appropriate threshold level _Vth by the comparator 6 so that R
An F signal is detected (step S5).

As described above, the RF in the lead-in area
By discriminating the "H" or "L" state of the detection signal _DRF , the compact disc or the recorded R-
It is determined whether the CD is a CD or a partially recorded R-CD. In this case, if the RF detection signal D _RF is “H”, the disc is a compact disc or a recorded R-CD, so that the TOC information is read as in the case of reproducing a conventional compact disc.
Thereafter, the program shifts to the reproduction of the program area (step S6).

If the RF detection signal _DRF is "L", the flow shifts to a pickup transfer routine (step S7). FIG. 3 shows the configuration of the pickup transfer routine. First, it is determined whether or not the optical pickup 2 can be further transported from the lead-in area to the outer peripheral side (step S21). This can be performed by detecting a position where it cannot go any further to the outer peripheral side by a mechanism similar to the sensor switch described above. In this case, if the optical pickup 2 cannot be further moved to the outer peripheral side, the disc is ejected (ejected) (step S22).

If the optical pickup 2 can be further moved to the outer periphery, the sled mechanism 3 moves the optical pickup 2 to the outer periphery (program area side) at a low constant speed (step S23). Also in this case, the spindle motor 9 remains stopped. At the same time, the ON the switch SW ₅ in the same manner as in step S4 described above (step S2
4) The presence or absence of an RF signal is detected (step S25).
This operation is repeated to approach the program area at a low constant speed from the inner peripheral side while monitoring the presence or absence of the RF signal. In this case, if the RF signal is not detected even when the outermost position of the disk 1 is reached, the disk is a completely unrecorded disk (virgin disk) and is ejected (ejected) to the outside of the player in step S22 as described above. In this case, the transfer of the optical pickup 2 without rotating the spindle motor 9 is performed in the case of normal CD reproduction by a CLV (Constant Linear Velocit) by the EFM signal.
y) Servoing, but C at the position where EFM signal cannot be obtained
This is because if the LV servo is performed, the spindle motor may run out of control. Also, if the spindle motor 9 is
It is also possible to transfer the optical pickup 2 by performing an AV (Constant Angular Velocity) servo drive, but in this case, if the disk is a virgin disk, the spindle is once used to eject the disk in step S22 in FIG. This is because it is necessary to stop the motor, and there is a disadvantage that useless steps increase.

If an RF signal is detected in step S25, it indicates that the vehicle has entered the program area in which the recording information has been written. Thus, where the tracking servo even performed by switching the changeover switch SW ₂ switches the spindle motor 9 in CLV servo drive in TE side (step S8), and reads the information of the program area, the subcode Q data which is temporal location information Is decoded (step S9). The subcode Q data is recorded in a memory (not shown) in the system controller 10 (step S10), and based on the subcode Q data, the optical pickup 2 is transferred to a pause area immediately before the first track (track number 1) (step S10). Step S1
1).

Next, an R-CD reproduction routine (step S1)
Go to 2). In the R-CD reproduction routine, reproduction is performed sequentially from the first track (step S31). In this case, since the provisional TOC of all recorded tracks has not been obtained, search reproduction cannot be performed. Next, it is determined whether or not the stop key has been pressed (step S32). If the stop key has not been pressed, the reproduction is being continued, so RF
It is determined whether there is a detection signal (step S33). If there is an RF detection signal, since there is recorded information, the information of the track is read and the subcode Q data is decoded (step S34). This subcode Q data is recorded in a memory (not shown) in the system controller 10 (step S35). If this subcode Q data is recorded for all recorded tracks, the temporary TOC
Therefore, when reproduction is performed again, search reproduction or the like can be performed. Next, check the track number,
It is determined whether the track number has changed (step S36). If the track number has changed, it is written to the start address of the track number table in the memory (step S38). If the track number has not changed, the end address of the track number table in the memory is updated. Then (step S37), the process returns to step S31, and the above procedure is repeated. If the stop key is pressed in step S32 or the RF detection signal is not detected in step S33, the reproduction is stopped, and the rotation of the spindle motor 9 is stopped (step S39). Finally, the optical pickup 2 is moved to the innermost peripheral standby position of the disk (step S40), and the reproducing operation is completed.

As described above, in this embodiment, when the optical pickup picks up the PTO when trying to read the temporary TOC in the PMA area.
Even a disc player having a structure that cannot be transported to the MA area can reproduce an R-CD by a simple control.

[0035]

As described above, according to the present invention,
There is an advantage that a partially recorded R-CD can be reproduced only by changing the algorithm of the system controller or the like by utilizing the function of the conventional reproduction-only disc player as much as possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a flowchart (1) for explaining the operation of one embodiment of the present invention.

FIG. 3 is a flowchart (2) for explaining the operation of the embodiment of the present invention;

FIG. 4 is a flowchart (3) for explaining the operation of the embodiment of the present invention;

FIG. 5 is a diagram showing a signal waveform of an RF detection signal in FIG. 1;

FIG. 6 is a diagram showing a recording format of a compact disc.

FIG. 7 is a diagram showing a recording format in a program area.

FIG. 8 is a diagram showing a recording format of an R-CD.

FIG. 9 is a diagram illustrating a recording state on an R-CD.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Disk 2 ... Optical pickup 3 ... Thread mechanism 4 ... Reproduction amplifier 5 ... EFM demodulator 6 ... Comparator 7 ... Servo circuit 8 ... Low-pass filter 9 ... Spindle motor 10 ... System controller 11 ... Oscillation circuit 14 ... Servo circuit 21 ... Objective lens 22 ... optical pickup main body 23 ... actuator P ... peak hold circuit SW ₁ to SW ₅ ... changeover switch

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 7/00 G11B 19/00-19/12

Claims (2)

(57) [Claims] 1. An additional recording apparatus comprising: an information recording area in which a plurality of information pieces can be recorded; and an index area for recording index information for information search when recording in all areas of the information recording area is completed. A method of reproducing a write-once optical disc, wherein the write-once optical disc is rotated while irradiating a light beam on the write-once optical disc to read out the record information, and wherein the index information is stored in the index area. A first step of detecting whether or not the information is recorded without rotating the write-once optical disc; and, when it is detected in the first step that no index information is recorded in the index area, the information is read. Transferring the pickup means to the first information piece while searching for the first information piece among the information pieces recorded in the recording area without rotating the write-once optical disc. When the pickup means reaches the first information piece, the record information is recorded while rotating the write-once optical disc and detecting whether or not the record information is present by the pickup means. And a third step of reading and reproducing the recorded information only in the portion where the information is recorded. 2. An additional recording apparatus comprising: an information recording area in which a plurality of information pieces can be recorded; and an index area for recording index information for information search when recording in all areas of the information recording area is completed. An optical disc reproducing apparatus capable of reproducing the recorded information from a write-once optical disc, comprising: a rotation unit for driving the write-once optical disc to rotate; a pickup unit for irradiating the write-once optical disc with a light beam to read information; Transport means capable of transporting means to an arbitrary position in the radial direction of the write-once optical disc; and control means for controlling the rotating means, the pickup means, and the transport means. The control means includes an index in the index area. Whether or not information is recorded is detected without rotating the write-once optical disc, and when it is detected that no index information is recorded in the index area, Moving the pickup means to the leading information piece while searching for the leading information piece among the information pieces recorded in the information recording area without rotating the write-once optical disc by the rotating means. When the pickup means reaches the first information piece, the pickup means detects whether or not the recording information is present while detecting the recording information only in a portion where the recording information is recorded. An optical disc reproducing apparatus which controls reading and reproducing.