JPH0536075A - Reproducing method for direct-read-after-write type optical disk and optical disk reproducer - Google Patents

Abstract

PURPOSE:To reproduce a partly recorded R-CD by preparing virtual index information from the aftermost information piece in a recording area at the time of the absence of the index information. CONSTITUTION:When a switch SW5 controlled by a system controller 10 is turned ON, an actuator 23 is vibrated in a tracking direction. A brightness and darkness is generated at a reflected beam light amount in the recorded part, the difference of the brightness and darkness with a tracking orthogonal direction is used as the amplitude of an RF signal, and an H or L is outputted by a comparator 6 as an RF detection signal. At the time of L, an optical pickup 2 is moved to an outer peripheral side, and the presence or absence of the RF signal is detected. When the RF signal is detected, a spindle motor 9 is CLV-servo driven, a switch SW2 is turned ON, a tracking servo is operated in order to read the information at the end of information track, the sub-code data of time position information is decoded, a leading address is calculated from the relative time information, the pickup 2 is moved in the leading position, and this is repeated until the leading track. Thus, the partly recorded R-CD can be reproduced.

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 disk reproducing method and an optical disk reproducing apparatus, and more particularly to a reproducing method and reproducing apparatus suitable for reproducing recorded information from a write-once optical disk in the middle of recording.

[0002]

2. Description of the Related Art Conventionally, an optical disc having a diameter of 12 cm or 8 cm, which is called a compact disc (CD), has been known. On this CD, as shown in FIG. 5, a lead-in area, a program area, and a lead-out area are formed from the inner circumference of the disc. The recorded signal is an EFM (Eight to Fourteen Modulation) modulated digital signal, and includes a main code which is main information such as music information, and a sub code such as a time code (Q data) indicating time information. Has been. EFM
The signal includes a clock signal. The clock signal is compared with the reference synchronization signal, and the correction amount is fed back to the spindle motor through 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.

In the lead-in area, TOC (Table of C
Index information called ontents) is recorded. In the TOC, the total number of songs recorded in the program area of the disc, the total playing time, etc. are recorded as subcodes. In the program area, as shown in FIG. 6, music information and the like are recorded as main chords, Q data of sub chords,
A track number (TNO) indicating a song number, a relative playing time (P-TIME) from the start of the track, and an absolute total playing time (A-) measured from the track number 1.
TIME) etc. are recorded. In the lead-out area, a lead-out code indicating the lead-out area is recorded.

CD having such a recording format
Is a read-only medium, but in recent years, a write-once compact disc (R-CD: Recordable Compa) that enables additional recording of information while adopting the same format as a CD.
ct Disk) was developed. The recording format of this R-CD is commonly referred to as "Orange Book", and although it conforms to the CD format, as shown in FIG.
CA (Power Calibration Area) area and PMA (Progra
m Memory Area) area is provided. These PCA
The area and the PMA area will be described later.

On the other hand, a guide groove is formed on the recording track of the R-CD, and this guide groove uses a carrier (carrier) of 22.05 KHz as data (ATI) indicating absolute time information.
P: Absolute Time In Pregroove (W) is wobbling (meandering) at a frequency modulated by FM. Then, a laser beam (recording beam) for recording information is tracking-controlled along the guide groove, and the number of revolutions of the spindle motor is controlled so that the center frequency of wobbling becomes 22.05 KHz. Also, it is possible to perform tracking servo and spindle servo.

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

Further, in addition to the normal absolute time information, special information is encoded in the ATIP information by a combination of the leading 1 bit (MSB) of data indicating "minute", "second" and "frame". In particular, when this bit combination is "1""0""1", the information of 3 bits of the 6th to 8th bits represents the recommended recording power (light intensity) on the disc. That is, "000"-
Eight stages of recommended recording powers are defined corresponding to eight combinations of each bit of "111". This recommended recording power is based on the condition that the recording beam has a wavelength λ = 780 nm (nanometer) and a temperature T = 25 ° C. However, in reality, the wavelength λ has temperature dependency and the aperture ratio of the objective lens. The optimum recording power (light intensity) does not always match the recommended recording power due to the difference in NA and the like.

The PCA area is an area in which test recording is performed prior to the recording operation in order to make the laser power proper during recording, and is formed of 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 ATIP information does not always match the optimum recording power. One test recording consumes one of the subdivided areas of the test area.

The area of the test area once test-recorded is unusable at the next test-recording. Therefore, it is necessary to search an unused area located on the inner circumference side of the disk. A count area is provided to facilitate the operation. That is, for example, when an appropriate EFM signal is recorded up to a certain area of the count area and the adjacent area is an unrecorded state, the area of the test area corresponding to this is a test recordable area. Is shown. Therefore, the optimum recording power may be measured by searching 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 therein. .

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

This is a partially recorded disc (Partia
This is because the TOC information cannot be recorded in the lead-in area until the completion of recording is finally instructed in the lly recorded disk) because information may be continuously recorded in the remaining program area. For this reason, it is necessary to temporarily record only the recorded information of each track. On the other hand, when the instruction to complete the recording that no further recording is given is given by the user's instruction or the instruction from the system controller, the TO
The C information and the lead-out signal are recorded respectively. In this case, the TOC information of the recorded PMA is
It is transferred to the lead-in area multiple times to ensure reliability. In this way, the RC
Since D (Finalized Disk) conforms to the CD format, A for decoding ATIP information
It can be played back even in a normal playback-only CD player that does not have a TIP decoder or the like. R-C in FIG.
The recording state in D is shown. 8A shows an unrecorded disc (virgin disc), FIG. 8B shows a partially recorded disc, and FIG. 8C shows a disc on which recording has been completed.

[0012]

However, in the partially recorded R-CD, since no information is recorded in the lead-in area as described above, in a normal read-only CD player, this area is not recorded. However, since the EFM signal is not obtained even when the spindle motor is accelerated / rotated, the spindle servo does not lock (converge), and there is a risk that the spindle motor will run abnormally and the rotation speed of the spindle motor will become abnormally high or reverse. Further, even if an attempt is made to perform the spindle servo by detecting the wobbling frequency, it is impossible because the conventional reproduction-only CD player is not provided with a means for detecting the wobbling. Further, there is a case where the pickup cannot transfer to the PMA area even if the temporary TOC in the PMA area is read.

Therefore, the present invention utilizes the function of the conventional read-only disc player as much as possible to make a partially recorded RC.
It is an object of the present invention to provide a reproduction method and a reproduction device that enable reproduction of D.

[0014]

In order to solve the above-mentioned problems, the invention according to claim 1 is such that an information recording area in which a plurality of information pieces can be recorded and recording in all areas of the information recording area is completed. In the case where the write-once type optical disc having index areas for recording index information for information retrieval is rotated, the recordable information is recorded using a pickup means for irradiating the write-once type optical disc with a light beam to read the recordable information. A method of reproducing a write-once optical disc for reproducing a write-once optical disc, the first step of detecting whether or not index information is recorded in the index area without rotating the write-once optical disc, and the index in the first step. When it is detected that the index information is not recorded in the area, the last information piece of the information pieces recorded in the information recording area is not rotated in the write-once optical disc. A second step of moving the pickup means to the last information piece while searching, and when the pickup means reaches the last information piece, the write-once optical disc is rotated to cause the pickup means to A third step of reading the last information piece and extracting and recording the temporal position information of the last information piece, and transferring the pickup means to the information piece immediately before the information piece based on the third time positional information. Then, the write-once optical disc is rotated to read the immediately preceding information piece by the pickup means, and the procedure for extracting and recording the temporal position information of the immediately preceding information piece is described with the time of the first information piece in the recording area. And a fourth step of sequentially repeating until the target position information is extracted and recorded.

According to a second aspect of the present invention, 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 a write-once optical disc comprising: a rotating unit for rotating the write-once optical disc; and irradiating the write-once optical disc with a light beam to read information. Pickup means, and transfer means capable of transferring the pickup means to an arbitrary position in the radial direction of the write-once type optical disc,
A control means for controlling the rotation means, the pickup means, and the transfer means, the control means detecting whether or not index information is recorded in the index area without rotating the write-once optical disc. When it is detected that the index information is not recorded in the index area, the last information piece of the information pieces recorded in the information recording area is recorded on the write-once read-many optical disc by the rotating means. When the pickup means is moved to the transfer means to the last information piece while searching without rotating, and when the pickup means reaches the last information piece, the write-once optical disc is rotated by the rotation means. By rotating the pick-up means to read the last piece of information and extract and record the temporal position information of the last piece of information, Based on the information piece, the pickup means is moved to the information piece immediately before the information piece by the transfer means, the write-once optical disc is rotated by the rotating means, and the information piece immediately before is read by the pickup means. The procedure for extracting and recording the temporal position information of the information piece is sequentially repeated until the temporal position information of the leading information piece in the recording area is extracted and recorded.

[0016]

According to the reproducing method and the optical disk reproducing apparatus of the write-once optical disc having the above-described structure, the write-once optical disc is rotated depending on whether index information (for example, TOC) is recorded in the index area (for example, lead-in area). If it is detected that the index information is not recorded, the last information piece of the information pieces (for example, individual music pieces) recorded in the information recording area (for example, program area) is detected. Again, the write-once optical disc is searched without rotating and the temporal position information (eg, subcode Q data) of this last information piece is read and recorded, and from this last information piece to the head information piece in reverse. By repeating the same procedure, the temporal position information of all information pieces is read to generate information (so-called temporary TOC) relating to the recording history of this disc, and based on this temporal position information. It reads desired recorded information from the information recording area. Therefore, even in an optical disk reproducing apparatus having a structure in which the pickup means or the like cannot transfer to the PMA area, the temporary TOC can be generated and the disk can be played based on this temporary TOC. At this time, the pickup means is moved while searching without rotating the disc until the last information piece is reached, so there is no risk of the rotation means (for example, the spindle motor) becoming uncontrollable.
Non-discs and completely unrecorded discs can be ejected immediately because the rotation means is stopped.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of an embodiment of the present invention.
As shown in FIG. 1, this disc player has an optical pickup 2 as a pickup means, a sled mechanism 3 as a transfer means, a reproduction 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 which is a rotating means, a system controller 10, an oscillation circuit 11,
Changeover switch SW ₁ , SW ₂ , SW ₃ , SW ₄ , SW ₅
And is configured. Here, the system controller 10, the servo circuits 7 and 14, the peak hold circuit P,
Low-pass filter 8, the changeover switch SW ₁ to SW ₅ constitute a control unit.

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

Read from the main body 21 of the optical pickup
The signal (read RF signal) is returned to the EFM via the reproduction amplifier 4.
In addition to being supplied to the regulator 5, the coupling capacitor C₁To
More AC coupled, more diode D₁and
Capacitor C₂By the peak hold circuit P consisting of
A voltage corresponding to the RF signal level is generated, which is
It is supplied to one input terminal of the parator 6. COMPARE
The other input terminal of switch 6 has a predetermined threshold level.
Voltage V_thIs supplied, and as a result, the comparator 6
Output is "H" or "L" depending on the presence or absence of RF signal.
RF detection signal D _RFTo detect. The output of the EFM demodulator 5 is
It is supplied to the servo circuit 14.

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

Each change-over switch is connected to a drive signal source for not only simply turning the servo loop ON / OFF but also forcibly driving the driven portion whose drive is controlled by the servo loop. For example, in the tracking servo loop, since the actuator 23 is caused to jump in the disk radial direction, the FWD having a polarity corresponding to the direction
The (forward) voltage and the REV (reverse direction) voltage are applied to the movable contact of the change-over switch SW ₂ in order to move the optical pickup at a high speed in the radial direction of the disk in the sled servo loop. F switch for accelerating and decelerating the spindle motor in the spindle servo loop to the movable contact of the changeover switch SW _3.
The WD voltage and the REV voltage are 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 reproducing operation of the partially recorded R-CD in this disc player will be described with reference to FIGS. As shown in FIG. 2, first, the optical pickup 2 is moved 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 within the 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 causing the optical pickup 2 to move by the sled mechanism 3 until the sensor switch is reached. it can.

Next, the focus servo is turned on and it is determined whether or not the focus is locked (converged) (step S2). The focus servo is retracted by using the means described in Japanese Patent Publication No. 63-13261, etc., and when the retracting operation is not completed within a predetermined time or within a predetermined number of retries (retries), etc. It is determined that the focus is unlocked (non-converged), and in this case, "no disk" is determined (step S3).

When the pull-in of the focus servo is completed, the changeover switch SW ₅ is closed (ON) while the spindle motor 9 is stopped (step 4). The changeover switch SW ₅ is the system controller 10
Is controlled by the switch. When the changeover switch SW ₅ is turned on, the output of the oscillation circuit 11 is mixed in the tracking servo loop. The oscillator circuit 11 is an oscillator circuit that oscillates at a single frequency. Therefore, the tracking servo loop is turned off (that is, the changeover switch SW ₂ is turned off).
F) When the switch SW ₅ is turned on, the oscillation output of the oscillation circuit 11 is supplied during the tracking servo loop, so that 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 so as to cross a plurality of tracks on the disk 1. Generally, the driving range of the tracking actuator is several hundred μm, and when the track pitch is 1.6 μm, 100 or more tracks are crossed.

Next, the waveform of the read RF signal reproduced by the optical pickup 2 when the information read beam crosses the track as described above will be described. First, when the actuator is vibrated in the tracking direction in the unrecorded portion so as to cross a plurality of recording tracks, RC
Read R depending on the presence or absence of the guide groove formed on the D disc.
The strength appears in the F signal waveform. This is called radial contrast (contrast in the radial direction of the disc). 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 a very small level. Therefore, the output level peak-held by the peak-hold circuit P is also extremely small, and the comparator 6 outputs "L" as the RF detection signal.

On the other hand, when the actuator is oscillated in the tracking direction at the recorded portion, the light quantity of the reflected beam becomes bright or dark due to the phenomenon that the laser beam is diffracted by the pits recorded in the traversed tracks. The RF signal can be obtained during normal reproduction by utilizing the principle that the reflected beam causes light and darkness due to the phenomenon that the laser beam is diffracted by the pits existing in the track tangential direction. That is, even if the beam is moved in the radial direction of the disk), there are pits in the tracks that cross it, so the frequency band is different,
A similar amount of light and darkness occurs. Since the difference between light and dark 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. 4 shows the waveform of the RF signal. At time t ₁ , the focus servo is pulled in, and at time t _{2, the} sled servo is started to move in the FWD direction while vibrating 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 the recorded program area is entered at time t ₃ , the amplitude of the RF signal increases due to the light and dark due to the diffraction phenomenon of the pits of each track. When the unrecorded area is reached at time t _4, the waveform again has a minute amplitude due to the radial contrast.
The time t ₅ is the time when the vibration of the actuator is stopped.

The RF signal thus fluctuating is AC-coupled by the capacitor C ₁ to remove the DC component, so that the peak hold circuit P eventually holds the peak value from the center value of the amplitude of the RF signal. Become. Then, this hold voltage is compared with an appropriate threshold level V _th by the comparator 6 so that R
The F signal is detected (step S5).

Thus, the RF in the lead-in area
By discriminating the "H" or "L" state of the detection signal D _RF , the compact disc or the R-
It is determined whether it 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 the TOC information is read as in the case of reproducing a conventional compact disc.
Then, the program area is reproduced (step S6).

When the RF detection signal D _RF is "L", the process moves to the 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 moved from the lead-in area to the outer peripheral side (step S21). This can be done by detecting the position where it cannot go further to the outer peripheral side by a mechanism similar to the above-mentioned sensor switch. In this case, if the optical pickup 2 cannot be moved further to the outer peripheral side, the disc is ejected (step S22).

If the optical pickup 2 can be further moved to the outer peripheral side, the sled mechanism 3 moves the optical pickup 2 to the outer peripheral side (program area side) at a low constant speed (step S23). In this case also, the spindle motor 9 remains stopped. At the same time, the changeover switch SW ₅ is turned on in the same manner as in step S4 described above (step S2
4) The presence or absence of the RF signal is detected (step S25).
By repeating this operation, the inner peripheral side approaches the program area, which is the information recording area, at a low constant speed while monitoring the presence or absence of the RF signal. In this case, if the RF signal is not detected even at the outermost position of the disc 1, the disc is a completely unrecorded disc (virgin disc) and is ejected (ejected) to the outside of the player in step S22 as described above.

When the RF signal is detected in step S25, it means that the program area in which the record information is written is entered. However, in the program area, a plurality of tracks (which may be considered as songs) that are information pieces are recorded, and it is necessary to specify which is the last track. This is because if the subcode is read from the first track, the optical pickup 2 suddenly enters the unrecorded portion after reading the last track, and the spindle motor 9 may run away at that point.
That is, in the case of normal CD reproduction, CLV (constant linear velocity: Constant Linear Velocit) is generated by the EFM signal.
y) Servo but C at a position where EFM signal is not obtained
This is because the LV servo may cause the spindle motor to run out of control.

Therefore, the optical pickup 2 is further transported to the outer peripheral side at the above-mentioned low constant speed (step S26). Also in this case, the changeover switch SW ₅ is turned on in the same manner as above.
Then, (step S27), the presence or absence of the RF signal is determined (step S28). The spindle motor 9 remains stopped during these operations. These operation steps S2
If 6 to S28 are repeated and then the RF signal is detected, it means that the program area is still in the program area.
When the F signal is no longer detected, it indicates that the F signal has passed through the program area and is further transferred to the outer peripheral side.
If the RF signal is no longer detected (step S2
8) Although it depends on the feed speed of the sled mechanism 3, the position is on the outer peripheral side by about 10 tracks from the program area, so the predetermined number of tracks (for example, 30 tracks) is returned to the inner peripheral side from this position (step S8). The optical pickup 2 is positioned on the last information piece of the recording track.

At this time, the spindle motor 9 is driven by the CLV servo, the changeover switch SW ₂ is turned on, and while the tracking servo is being performed (step S9), the information of the last track (song) is read and the temporal position information is obtained. Decode the subcode Q data that is (step S
10) Calculate the start address of the track (song) from the relative time information, and then move the optical pickup 2 to the start position of the track (song) by the sled mechanism 3 based on the calculated start address. Then (step S
11) Read the subcode Q data at the leading position. The decoded subcode Q data is recorded in a memory (not shown) in the system controller 10 as temporary index information (hereinafter referred to as “temporary TOC”) (step S12).

These procedure steps S8 to S12 are repeated until the head track is reached. When the first track (that is, track number = 1) is reached (step S1)
3) Since the provisional TOC of this R-CD is obtained, it is possible to reproduce desired information (for example, music piece) in the program area which is the information recording area.
Therefore, here, the spindle motor 9 is switched to the CLV servo drive, the selector switch SW ₂ is switched to the TE side, and the tracking servo is also performed to start the information reading / reproducing operation (step S14).

As described above, in this embodiment, the temporary TOC can be created even with the disc player having the structure in which the optical pickup cannot move to the PMA area.
Based on this provisional TOC, desired information in the program area can be read and reproduced. Step S for searching the last track of the program area in this embodiment
In the case of No. 7, it is possible to drive the optical pickup 2 by CLV servo-driving the spindle motor 9 as in step S9 or S10, but in that case, since the EFM signal cannot be obtained in the lead-in area, the spindle motor is There is a risk of runaway, and CAV (Constant angular velocity: Cons
tamt Angnlar Velocity) Even if servo is performed, if the disk is a virgin disk, it is necessary to stop the spindle motor once to eject the disk in step S22 of FIG. .

[0037]

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

[Brief description of drawings]

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

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

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

FIG. 4 is a diagram showing a signal waveform of an RF detection signal in FIG.

FIG. 5 is a diagram showing a recording format of a compact disc.

FIG. 6 is a diagram showing a recording format in a program area.

FIG. 7 is a diagram showing a recording format of R-CD.

FIG. 8 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

Claims (2)

[Claims] 1. An additional recording comprising: an information recording area capable of recording a plurality of information pieces; and an index area for recording index information for information retrieval when recording of all the information recording areas is completed. A reproducing method of a write-once optical disc which reproduces the record information by using a pickup means for irradiating the write-once optical disc with a light beam to read the record information while rotating the write-once optical disc. The first step of detecting whether or not the information is recorded without rotating the write-once optical disc, and if it is detected that the index information is not recorded in the index area in the first step, the information is recorded. Of the information pieces recorded in the recording area, the last information piece is searched for without rotating the write-once optical disc, and the pickup means is moved to the last information piece. The second
And, when the pickup means reaches the last information piece, the write-once optical disc is rotated and the last information piece is read by the pickup means, and the temporal position information of the last information piece is read. And the third step of extracting and recording the information piece, and transferring the pickup means to the information piece immediately before the information piece based on the temporal position information, rotating the write-once optical disc, and immediately before the information piece by the pickup means. And a procedure of extracting and recording the temporal position information of the immediately preceding information piece is sequentially repeated until the temporal position information of the leading information piece in the recording area is extracted and recorded.
A method of reproducing a write-once optical disc, comprising: 2. An additional recording comprising: an information recording area capable of recording a plurality of information pieces; and an index area for recording index information for information retrieval when recording of the entire information recording area is completed. An optical disc reproducing apparatus capable of reproducing the recorded information from a write-once type optical disc, a rotating means for rotating the write-once type optical disc, and a pickup means for irradiating the write-once type optical disc with a light beam to read information. And a control means for controlling the rotation means, the pickup means and the transfer means, the control means indexing the index area. Whether or not information is recorded is detected without rotating the write-once read-many optical disc, and when it is detected that index information is not recorded in the index area. Among the information pieces recorded in the information recording area, the rearmost information piece is searched by the rotating means without rotating the write-once read-many optical disc, and the last information piece is transferred to the transfer means. When the pickup means is moved and the pickup means reaches the last information piece, the rotating means rotates the write-once optical disc to read the last information piece by the pickup means. Of the information piece, the temporal position information of the information piece is extracted and recorded, and based on the temporal position information, the pickup means is transferred to the information piece immediately before the information piece by the transfer means, and the write-once optical disc is rotated by the rotation means. Is rotated to read the immediately preceding information piece by the pickup means, and the temporal position information of the immediately preceding information piece is extracted and recorded. Procedure optical disk reproducing apparatus and controls to repeat successively to said recording extracting time position information of the head of the information pieces of territory records.