JPH07141660A - Optical disk device - Google Patents

Abstract

PURPOSE:To set the optimum light quantity range of a light beam in the test region within a PCA at every disk change in a region where a power source is closed, then to finely adjust this light quantity to the optimum within a program region. CONSTITUTION:A session 1 has a reading region 3 and a reading out region 4 before and after one program region 2. This program region 2 is divided to tracks of the number of data. The divided tracks 5 are composed of regions 7 of index '00' and regions of index '01'. The region 6 plays the role of a discriptor for identifying the tracks 5 and the region 7 is a user region composed of a packet 8 and includes a link region 9, a line region 10, a runout region 11 and a user data region 12. The limitation on the number of adjustment times is eliminated by executing trail writing in the user region and adjusting the light quantity of the light beam.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device capable of recording data on an optical disk.

[0002]

2. Description of the Related Art As one application of an optical disk, a write-once (WO) optical disk (hereinafter referred to as CD-R) has been proposed. The CD-R has an information recording surface formed by adhering an organic dye to a disc-shaped substrate of polycarbonate, for example, and the information recording surface is protected by a protective layer. As a result, the optical disk device intermittently irradiates the light beam to thermally change the organic dye on the information recording surface, thereby forming an area having a low reflectance on the information recording surface.

The data structure of the CD-R will be described below. FIG. 9 shows the data structure of the innermost portion of the CD-R. This part is addressed on the inner side of the lead-in area toward the center from 00 (minute): 00 (second): 00 (frame) to 00:35:36. . Here, 1 second is 75
It is a frame. Further, the CD-R has a wobbling groove for tracking, and by performing FM modulation on this wobbling groove, the absolute time (ATIP) is recorded. That is, the absolute address on the optical disc is recorded in advance.

Reference numeral 51 denotes a light amount adjustment area (PCA).
The PCA 51 is divided into a test area 52 for adjusting the light amount of the light beam during recording and a count area 53 for recording the usage state of the test area 52. The test area 52 has a range of (00:15:35 to 00:35:35), that is,
It consists of 1500 frames, and the count area 53 is (0
The range is from 0:13:55 to 00:15:05, that is, 100 frames.

The test area 52 is divided into 100 areas (referred to as partitions) 54, so that one partition is composed of 15 frames. The count area 53 is also divided into 100 areas (referred to as partitions) 54, like the test area 52.

In each partition 54 of the test area 52, in order to optimally adjust the light quantity of the light beam at the time of recording,
Test data is recorded in which the light intensity gradually decreases from the maximum light intensity of the light beam. At this time, a recorded mark is attached to the partition of the count area 53 corresponding to the partition of the test area 52. The partition of the count area 53 and the partition of the test area 52 correspond to each other on a one-to-one basis. By checking the partition of the count area 53, whether the partition of the test area 52 corresponding to the partition of the count area 53 has been recorded or not. Can be determined. FIG. 9 shows an example in which the first partition to the third partition have been used.

Reference numeral 55 represents a program memory area (PMA) having a size of 50 frames. The PMA 55 records the disc identification information and a part of the data of the track in the middle of recording, that is, serves as a temporary memorandum.

[0008]

As mentioned above, the CD-R is used.
In the above configuration, the area of the PCA 51 for recording is
Area for 100 times is prepared. However, 100
When performing recording more than the number of times, there is a problem that the area for adjusting the light amount of the light beam at the time of optimum recording is insufficient only with the PCA 51. In particular, in a system that always adjusts the light intensity of the light beam during optimal recording before recording data,
The number of recordings is limited.

On the other hand, when the data recording is performed by omitting the adjustment of the light amount of the light beam at the time of the optimum recording, the data is not recorded at the optimum light amount of the light beam, so that the error rate of the data is deteriorated. In the worst case, the recorded data may become unreadable.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above problems and provide an optical disk device capable of adjusting the light quantity of a light beam a number of times.

[0011]

According to the present invention, test data is recorded in a light amount adjustment area on an optical disk, and the test data is reproduced to adjust the light amount of a light beam during recording. In the optical disc device,
The optical disk device is characterized in that test data is recorded in a data recording area other than the light amount adjustment area in accordance with the recording format of the data recording area.

[0012]

By using the present invention, it becomes possible to optimally adjust the light amount of the light beam more than 100 times in the CD-R.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical disk device according to the present invention will be described below with reference to the drawings. First, using FIG. 1, the CD-R
The overall data structure of is described. 1 indicates a data unit additionally written called a session. CD-R is P
It is composed of a CA 51, a PMA 55, and a plurality of sessions 1. Each session is composed of a program area 2, a lead-in area 3 and a lead-out area 4 before and after the program area 2.

FIG. 1B shows the detailed data structure of this session 1. The program area 2 sandwiched between the lead-in area 3 and the lead-out area 4 is given a track number TNO according to the number of recorded data. In this embodiment, one session has three data tracks. Each track 5 separated by the track number TNO is composed of two areas distinguished by an index.

FIG. 1C shows a detailed data structure of one track 5. The track descriptor is recorded in the area 6 whose index is "00". The index is `
The area 7 of 01 'is a recording area of user data, and the packet 8 is a unit. There are three methods for recording desired data in this area 7. That is, there are a track-at-once method, a fixed-length packet method, and a variable-length packet method, and these methods can be appropriately selected. The track descriptor has information that distinguishes these recording methods. Figure 1
Shows a fixed length packet system, that is, a data structure in which the length of one packet is 32 blocks and is constant, as an example of this.

FIG. 1D shows the detailed data structure of the packet 8. The link block area 9 is located at the head of the packet 8. The link block area 9 constitutes a connection portion with the previous packet together with the run-in area. The illustrated example is a fixed length packet system in which the packet length is 32 blocks. The user data area 12 sandwiched between the run-in area 10 and the run-out area 11 is composed of 32 blocks. At this time, the run-in area 10 and the run-out area 11 are guard areas in which data cannot be recorded due to the structure of the error correction code (cross interleaved Reed-Solomon code) of the optical disc.

Packet 8 shown in FIG. 1D is a fixed length packet. Next, the track-at-once method and the variable-length packet method will be described. FIG. 2 shows the data structure of a track-at-once packet. In the area 6 having an index of "00", that is, in the track descriptor, information indicating that this packet is the track-at-once method is recorded. Area 7 whose index is '01' is a user data recording area, and in the track-at-once method, run-out area 1
Pseudo signals (for example, data of all "0") are recorded up to 1. The link blocks 15 are composed of a link block area 9, a run-in area 10, and a run-out area 11, as described later.

FIG. 3 shows a data structure of a packet of the variable length packet system. In the area 6 having an index of "00", that is, in the track descriptor, information indicating that this packet is a variable length packet system is recorded. The area 7 having an index of “01” is a user data recording area, and each packet has an arbitrary number of blocks of 8 blocks (the user data area 12 is 1 block) or more. The link blocks 15 include the link block area 9 and the run-in area 1 as described later.
0, run-out area 11.

FIG. 4 shows a data structure of a fixed length packet type packet. In the area 6 whose index is "00", that is, in the track descriptor, this packet is of fixed length packet type, and the size of the packet, in the illustrated example, packet length = 18 blocks is recorded. The area 7 having an index of "01" is a user data recording area and is composed of the number of blocks of the packet recorded in the track descriptor.
The link blocks 15 are composed of a link block area 9, a run-in area 10, and a run-out area 11, as described later.

FIG. 5 shows the data structure of the link block 15 described above in detail. This link block 15
Link block area 9 is one block, run-in area 10
Is composed of 4 blocks and the runout area 11 is composed of 2 blocks, that is, a total of 7 blocks. The data structure of the link block 15 is that the link block 15 of the current packet is the link block area 9 and the run-in area 1.
FIG. 5 shows that the link block 15 of the packet immediately before the current packet is 0 and is the runout area 11.

In this embodiment, in addition to PCA51,
The program area 2, that is, the user data area 12 is also used as a light amount adjustment area of the light beam. More specifically, a specific track is used for adjusting the light quantity, and the light quantity of the light beam is adjusted using the packet 8 as one unit.

As an example, a desired track in the program area 2 in FIG. 1 is used for adjusting the light quantity of the light beam. Information (predetermined code) indicating that this track is for light intensity adjustment is recorded in the run-in area and the run-out area of the track descriptor. Since the run-in area and the run-out area are information unrecorded areas, normally recorded data are all recorded with "0" or "1". In the present invention, the run-in area 10 and / or the run-out area 11 have a value of "0".
Alternatively, by recording data other than "1", it is identified that this track is the light amount adjustment area.

As described above, the run-in area 10 and the run-out area 11 are sections in which no data can be recorded, but four blocks are additionally provided in view of a margin, and from this point, data is stored in these areas. It is possible to record in.

In the optical disk device of the present invention, the light quantity adjustment of the light beam is performed in the test area 52 and the program area 2 in the light quantity adjustment area (PCA) 51. At this time, the optical disc device detects whether or not this program area is a program area for adjusting the light amount. Also, in the program area for this light quantity adjustment, the identification of the tail end where the light quantity of the light beam has been adjusted,
The optical disk device detects from the level change of the reproduction RF signal.

The recording method of the light quantity adjusting track may be either a fixed length packet method or a variable length packet method. Then, if the track length is set to 2 minutes, 1000 packets can be recorded in the track, and therefore 1000 packets can be recorded.
It is possible to adjust the light intensity once.

Next, an optical disk device according to the present invention will be described with reference to the drawings. FIG. 6 shows a schematic diagram of a block diagram of the optical disc apparatus. The optical disc 21 is a disc-shaped recording medium having an information recording surface formed of, for example, an organic dye, and the servo circuit 23 causes the spindle motor 2 to rotate.
By controlling the rotation of No. 2, the optical disk 21 is rotationally driven at a predetermined constant linear velocity (CLV). Optical disc 21
An optical block 25 is provided on the sled 24 for recording data on and reproducing data from the optical disc 21. The sled 24 is sent by a linear motor or the like in the radial direction of the optical disk 21.

Reflected light obtained by irradiating the optical disk 21 with a light beam is received by a light receiving element (for example, a 4-division detector), and the optical block 25 amplifies the output signal of this light receiving element and outputs it to the matrix circuit 26. . The matrix circuit 26 performs addition / subtraction processing on the signals supplied from each detector from the four-division detector to generate a reproduction RF signal, a focus error signal, and a tracking error signal. The generated signal is supplied from the matrix circuit 26 to the servo circuit 23. The servo circuit 23 uses the supplied focus error signal and tracking error signal to generate control signals for feeding the sled 24 in the disk radial direction and tracking and focus control of the optical block 25.

As a result, tracking control and focus control are performed so that a pit can be reliably formed at a predetermined position by these controls.
The data can be surely reproduced. Further, the optical disk 21 is formed by wobbling a groove corresponding to the pit formation position in advance, and a tracking error signal is generated based on this groove. Further, the wobbling is FM-modulated, and by demodulating this, the optical disc 21
The position information (ATIP) of the above is detected.

This position information is supplied to the CPU block 29, and the CPU block 29 controls the access corresponding to the optical disk 21 on the basis of this position information, whereby the optical disk device sequentially writes data to a predetermined area. It is designed to be recordable.

Here, at the time of recording, data is recorded by thermally changing the organic dye to form pits. The optical disk device is characterized in that the pit size changes depending on the ambient temperature and the sensitivity of the organic dye even when the laser diode is driven under the same conditions. Therefore, in the optical disc device, the light amount of the light beam is sequentially switched to record the test data in the light amount adjustment area, and then the test data is reproduced to detect the asymmetry. Further, the optical disc device selects the control signal data of the light quantity of the light beam for which the asymmetry becomes the optimum value, based on the asymmetry detection result, and records the desired data with the optimum light quantity. As a result, the optical disk device can always form pits having a constant shape even when the ambient temperature or the like changes, thereby reducing the jitter or the like of the reproduction signal.

Here, the asymmetry represents the ratio of the time average of pits and lands, which is logical `in the reproduced data.
It is expressed by a relational expression between the slice level at which the occurrence probabilities of 0'and '1' are equal to the peak level and bottom level of the reproduction signal. Peak level from slice level to `A '
, Asymmetry Asy is expressed by the equation (1) with the slice level to the bottom level as `B '.

Asy = (B−A) / (2 × (A + B)) (1)

Optical block 25 to matrix circuit 2
The signal supplied to the RF processing circuit 27 via 6 generates a reproduction RF signal and is supplied to the asymmetry detection circuit 28. The asymmetry detection circuit 28 detects the signal level of the reproduction RF signal as described later, and the detection result of this signal level is converted into a digital signal by the CPU block 29.
Is supplied to.

The CPU block 29 detects the asymmetry of the test data recorded in the predetermined light amount adjustment area by using the detection result from the asymmetry detection circuit 28, and at the time of recording so that the detected asymmetry becomes a predetermined value. The light amount control data for setting the light amount of the light beam is generated. That is, the CPU block 29 outputs the light amount control data to the automatic light amount control circuit 30 so that the light amount of the light beam can be freely set, whereby the light amount of the light beam at the time of recording is set to an optimum value. Further, during recording and reproduction, the light amounts of the light beams can be switched to the recording and reproducing light amounts, respectively.

Further, the CPU block 29 controls the servo circuit 23 and the automatic light amount control circuit 30 before the start of recording to switch the light amount of the light beam stepwise from the maximum value and to set a predetermined value for each light amount of the light beam. Is recorded in the light amount adjustment area of the optical disc 21, and then the test data is reproduced by switching to the light amount at the time of reproduction.

Here, the test data has a pulse width of 3T to 11
The CPU block 2 is formed by the recording signal of T.
9 detects the asymmetry of the test data recorded on the optical disc 21 with the light amount of each light beam, and stores the data of the control signal of the light amount of the light beam in the memory 31 from the detected asymmetry. Then, the optimum light amount of the light beam at the time of recording is set by reading the data of the control signal of the light amount of the light beam for which the asymmetry is optimum from the memory 31.

An example of the asymmetry detection circuit 28 will be described with reference to FIG. This asymmetry detection circuit 2
Reference numeral 8 inputs the reproduction RF signal to the differentiating circuit 41, differentiates the reproduction RF signal which changes in a sine wave form, and reproduces this reproduction RF signal.
At the timing of rising to the signal peak level and falling to the bottom level, a differential signal whose signal level crosses the `0` level is generated. The comparator circuit 42 detects the signal level of the differential signal with reference to the `0` level, thereby generating an output signal in which the signal level switches at the timing when the differential signal crosses the` 0` level, and detects the edge. The circuit 43 outputs edge detection signals POS and NEG in which the signal level rises at the rising edge and the falling edge of this output signal and the signal level falls after a predetermined period has elapsed.

The sampling pulse generation circuit 44 generates the first and second sampling pulses whose signal levels rise at the timing when the signal levels of the edge detection signals POS and NEG rise, and the sampling pulses are sampled and held by the sample hold circuit (S). / H) 46 and 47. Sample and hold circuits 46 and 4
Reference numeral 7 samples and holds the reproduced RF signal based on the first and second sampling pulses, respectively.

As a result, as shown in FIG. 8, in the asymmetry detection circuit 28, in the sample hold circuit 46, the reproduced RF signals are successively reproduced at the timings tP1, tP2, tP3, ... At which the signal level of the reproduced RF signal rises to the peak level. The signal level of the reproduction RF signal is sequentially sampled at the timing tN1, tN2, tN3, ..., At which the signal level of the reproduction RF signal falls to the bottom level in the sample hold circuit 47. It is designed to sample levels.

The peak-bottom hold circuit 48 holds the peak value and the bottom value of the sample-hold results of the sample-hold circuits 46 and 47, respectively, to reproduce a land having a pulse width of 11T and obtain a reproduction RF.
Peak level RFTOP of signal, bottom level RFB of reproduced RF signal obtained by reproducing pit with pulse width 11T
Reproduction R obtained by reproducing land with TM and pulse width 3T
Peak level 3TTOP of F signal, bottom level 3T of reproduced RF signal obtained by reproducing pit with pulse width 3T
BTM is detected and the detection result is output to the CPU block 29.

As a result, the CPU block 29 has the following expression (2).

[0042]

[Equation 1]

The arithmetic processing (1) is executed to detect the asymmetry Asy. That is, in the optical disc 21 of this output, the probability of occurrence of pits and lands having a pulse width of 3T occupies 1/3 of the whole. Therefore, if the peak level 3TTOP and bottom level 3TBTM of the pulse width 3T are added, a logical `0 'And `1'
It is possible to detect a level twice as high as the slice level SL at which the occurrence probabilities of the same occur.

Therefore, it is possible to easily detect the asymmetry Asy by executing the arithmetic processing of the equation (2) corresponding to the equation (1). At this time, in the asymmetry detection circuit 28, the peak level and the bottom level are sequentially sampled, and then the minimum value and the maximum value of each sampling result are detected and the peak level 3TTOP and the bottom level 3TBTM of the pulse width 3T and the peak of the pulse width 11T are detected. By detecting the level RFTOP and the bottom level RFBTM, it is possible to detect the asymmetry Asy in a much shorter time than before, and therefore, the light quantity of the light beam at the time of recording can be adjusted in the short light quantity adjustment area. .

By using the above-described asymmetry detection method, the light quantity of the light beam can be adjusted in 8 blocks, which is the minimum unit of the packet 8.

According to the above configuration, after the peak level and the bottom level are sequentially sampled, the minimum value and the maximum value of each sampling result are detected and the peak level 3TTOP and the bottom level 3TBT having the pulse width 3T are detected.
By detecting the peak level RFTOP and the bottom level RFBTM with the pulse width M and the pulse width 11T and detecting the asymmetry based on the detection result, the asymmetry can be detected easily in a short time. With, it is possible to adjust the light amount of the light beam during recording.

As described above, in adjusting the light amount of the light beam, the light amount is gradually reduced from the maximum light amount to record the test data, and the recorded test data is read to perform the optimum light amount adjustment of the light beam.

In the present invention, the light quantity adjustment of the light beam is performed in the test area 52 and the program area 2 in the light quantity adjustment area (PCA) 51. However, in the program area 2, conventionally readable digital data is recorded. Therefore, when the program area 2 is used for adjusting the light amount, if the light amount is adjusted, the unreadable range is also included, and the optical disc device determines that such an optical disc is defective in recording. In order to avoid this problem, the light amount of the light beam is adjusted in two steps.

That is, in the test area in the PCA 51 at power-on or every time the disk is replaced,
The optimum light amount range of the light beam is set, and as the next step, the optimum light amount fine adjustment of the light beam within the light amount range is performed in the program area.

The PCA 51, that is, the test area 52 for adjusting the light amount of the light beam and the count area 53 for recording the usage state of the test area 52 are the PCA 51.
And the program memory area (PMA) 55 between the program area 2 and the lead-out area 4 can be configured as a light amount adjustment area when the number of times exceeds 100 times.

[0051]

According to the present invention, it is possible to maintain the quality of recorded data and record data more than 100 times in the write-once type optical disc apparatus. Therefore, the amount of light can be adjusted to the optimum value for each additional write operation over 100 times.

In the recording in the program area, 100
Since data is recorded more than once, the optimum adjustment of the light amount of the light beam more than 100 times is an essential function of the write-once optical disc device.

[Brief description of drawings]

FIG. 1 is an example of a data structure on an optical disc to which the present invention is applied.

FIG. 2 is a schematic diagram of an example of a data structure of a track of a write-once optical disc.

FIG. 3 is a schematic diagram of an example of a data structure of a track of a write-once optical disc.

FIG. 4 is a schematic diagram of an example of a data structure of a track of a write-once optical disc.

FIG. 5 is a schematic diagram of an example of a packet connection portion of a write-once optical disc.

FIG. 6 is a block diagram of an example of an optical disc device.

FIG. 7 is a block diagram of an example showing an asymmetry detection circuit.

FIG. 8 is a signal waveform diagram for explaining the operation.

FIG. 9 is a schematic diagram showing an example of a data structure on the inner circumference side of a conventional write-once optical disc.

[Explanation of symbols]

 2 program area 3 lead-in area 4 lead-out area 5 tracks 8 packets

Claims (3)

[Claims] 1. A test data is recorded in a light amount adjustment area on an optical disc, and the test data is reproduced to adjust the light amount of a light beam during recording.
In the optical disc device, test data is recorded in a data recording region other than the light amount adjusting region according to a recording format of the data recording region. 2. The optical disk device according to claim 1, wherein identification information for identifying a data recording area in which the test data is recorded is recorded. 3. The optical disk device according to claim 1, wherein the data recording area is made up of a fixed-length or variable-length recording unit including a predetermined redundant section, and the recording information includes identification information as test data. An optical disk device characterized by recording in a redundant section.