JPS6142736A - Recording and reproducing disk and its using method - Google Patents

Abstract

PURPOSE:To improve the reliability of writing and reading operation by performing adaptive control over the light quantity power of write laser light to and that of read laser from a write and read area according to a radial position on a disk. CONSTITUTION:A switching circuit 19 is switched to the side of a contact a2 in, for example, playback mode with a switching control signal and initial data is read out of a recording area and stored in a memory 23. In a readout operation state, switching circuits 19 and 27 are switched to sides of contacts a2 and b2 with the switching control signal to supply a readout output RD to a light quantity power control circuit 17 and a setting circuit 28 is controlled with a setting signal 13 obtained from the initial data stored in the memory 23, so that a comparing circuit 18 generates a control signal S5 which controls the control circuit 17 so that the light quantity power varies according to a constant curve as laser light scans on the innermost diameter part, intermediate part, and outermost diameter part of the write and read area. Consequently, the reliability of writing and reading operation is further improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording/reproducing disk and a method of using the same, such as D RAW (direct read after).
This method is suitable for application to (r write) discs.

[Conventional technology]

DRAW discs record information by causing a change in the crystalline state on the recording film surface using the heat generated when laser light is irradiated, and the reflectance of this recording film surface changes depending on the recorded information. It is designed to reproduce information by using it.

[Problem that the invention seeks to solve]

However, in such a recording and reproducing disk that allows optical recording and reproducing, the melting point of the material constituting the recording film is relatively low (for example, about 200 to 300°C), so the laser light to be supplied during recording (this is (referred to as writing laser beam)
There is a drawback that the difference between the light amount and power of the laser beam and the light amount and power of the laser beam (this is called a readout laser beam) to be supplied at the time of successive output cannot be made sufficiently large.

For example, when an amorphous layer is used as the recording film, information is recorded by crystallizing the amorphous layer by irradiating it with a writing laser beam LW having relatively high power as shown in FIG. On the other hand, in the case of continuous writing, written information is read by irradiating the amorphous layer with a read laser beam LR having a smaller light amount and power than the writing laser beam LW.Here, the intensity of the read laser beam LR is: Although it is necessary to use a laser beam weak enough not to cause any change in the state of the amorphous layer formed during writing, the value of the optimum light amount power P1 of the writing laser beam originally depends on the material constituting the recording film. Since the value is limited to a low value due to the melting point of the reading laser beam LR, there is a problem that information cannot be read out without error unless a strictly controlled value is used as the optimum light amount power P2 of the reading laser beam LR.

In reality, the crystalline state of the material of the recording film varies depending on the manufacturing conditions when manufacturing the disk, so the optimum sight power P1 of the writing laser beam LW and the optimum sight power P2 of the reading laser beam LR vary considerably. Furthermore, it is considered that the amorphous portion of the recording film tends to crystallize little by little over time, and as a result, the value of the optimum light amount power P2 of the readout laser beam LR also changes over time.

In addition, since this type of disk is disc-shaped, the circumferential speed of each track that is formed from the inner circumference to the outer circumference increases, so the intensity of the laser beam to be irradiated can be kept constant. If so, there is a problem that the light amount power of the laser beam per unit area is weaker at the outer circumferential portion than at the inner circumferential portion, and therefore the optimum light amount power P1 of the writing laser beam LW and the optimum light amount power P2 of the reading laser beam LR are needs to be changed along the write characteristic curve CW and continuous characteristic curve CR as shown in Fig. 3, which makes it difficult to set the intensity of the laser beam to the optimum light amount power during recording and reading. It is thought that this is becoming increasingly large.

From the above points, it is a conventional DRAW disc body.

There have been problems in that it is difficult for users to use DRAW disks as recording media because of poor compatibility, poor manufacturing yields, and variable error rates when writing and reproducing information.

The present invention has been made in consideration of the above points, and is a recording and reproducing disk that can sufficiently correct the above-mentioned shortcomings that conventional optical disks inherently have when writing or continuously distributing information, and its use. This is an attempt to propose a method.

[Means for solving problems]

Firstly, the present invention provides a data recording area in which, in an optically recordable and reproducible recording/reproducing disk 1, initial data regarding the optimal light amount power for recording and reproducing at a predetermined position in the radial direction during manufacturing is formed on the inner circumference. Record in pit shape on 3A.

Second, the present invention provides a method for using the recording/reproducing disk manufactured in this way, when recording information on the recording/reproducing disk 1 or reproducing information from the recording/reproducing disk 1. The initial data recorded on the inner circumferential portion is reproduced, the reproduced data is held by the holding means 23, the held data is sequentially read out according to the radial position of the recording or reproduction scan, and based on the read data. The light amount power of the reproduction light is controlled.

[Effect]

The data regarding the light quantity and power for the radial position recorded on the disk 1 during manufacture is read out during reproduction, and the data is used to generate a reproduction light having a specified light quantity and power corresponding to the scanning radial position. Accordingly, the light amount power of the reproduction light can be adaptively controlled to the optimum value for the position in the radial direction.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings.

In Fig. 1, reference numeral 1 denotes a recording/reproducing disk, which has a write/read area 2, into which information is written using a writing laser beam LW (Fig. 2) with relatively strong sight power. The stored information can be read out using a readout laser beam LR (FIG. 2) having a relatively weak light amount and power.

Data recording areas 3A and 3B are provided inside the write/read area 2, that is, on the inner circumference of the disk 1, and on the outside, that is, on the outer circumference of the disk 1. In the inner part 3AI of the data recording area 3A, initial data unique to each recording/reproducing disc is pre-cut into a pit shape by a laser beam at the time of manufacturing the recording/reproducing disc 1, and the outer part 3AU of the data recording area 3A and the data recording In the area 3B, when the user uses the recording/reproducing disc 1 thereafter, user data for knowing the change over time of the recording/reproducing disc 1 can be recorded and reproduced.

Here, the following data is written in the recording area 3AI as the initial data ID.

(1) Data regarding the optimum write light amount power P1 and the optimum read light amount power P2 of the innermost diameter (effective innermost diameter) portion of the write/read region 2.

This data represents the optimum intensity of the laser beam required when writing or reading information to or from the innermost diameter portion of the write/read area 2 of the disc 1.

(2) Data on the writing optimum sight power P1 and the reading optimum light amount power P2 at the outermost diameter (effective outermost diameter) portion.

This data represents the optimum intensity of the laser beam required when writing or reading information to or from the outermost diameter portion of the writing/reading area 2.

(3) Data on the optimum write light amount power P1 and the optimum read light amount power P2 for a midpoint position in the radial direction of the write/read area 2;

This data represents the optimum intensity of the laser beam when writing or reading information at a predetermined position in the radial direction in the writing/reading area 2. As the radius increases, as shown by the writing characteristic curve CW and the successive characteristic curve CR in FIG. Therefore, the song wACW and C
In order to write and read information with a strength as close as possible to R, data at intermediate positions is written and
A laser beam with an intensity matching the X-optimal fluorescence data is generated. In practice, each value of the characteristic curves CW and CR is measured when writing a sector to each track during the manufacture of the disk 1.

The data at these intermediate positions may be collected and recorded continuously over the entire range in the radial direction of the write recording area 2. However, if a sufficiently wide area cannot be secured as the data recording area 3A, data at discrete positions may be collected. Collect and record data about the curve, or parameters about the curve between the innermost radius position and the outermost radius position (for example, a parameter representing the squared curve ratio)
When data or parameters at discrete positions are recorded in this way, when using these initial data, the recording/reproducing device performs interpolation calculations for each position in the radial direction. .

Further, the following data is recorded and reproduced as user data in the recording areas 3AU and 3B.

(4) User data This data is used when the user uses the disc 1 to generate a laser beam with an intensity that allows the user to measure changes over time that the disc 1 undergoes and compensate for this change. Then, the user writes test data for checking any signal format to the data recording area 3AU and/or 3B, and reads this written data (then
When the content of the test data written on the disc 1 matches the content of the test data read out, it is determined that the intensities of the write laser beam LW and the read laser beam LR for the disc 1 are at the optimum light amount power. I can think. On the other hand, when the contents of the read data and the contents of the written test data do not match, either or both of the write laser beam LW and the read laser beam LR do not have the optimum sight power. Therefore, the intensities of the writing laser beam LW and the reading laser beam LW are adjusted until a match is obtained.

Here, the reason why the outer data recording area 3B is provided in addition to the inner data recording area 3AU is that when the change over time that the write/read area 2 of the disk 1 undergoes is different at each position in the radial direction, the inner data recording area 3AU is provided. If you use the data in the data recording area 3AU and the data in the outer data recording area 3B,
The intensity of the laser beam for the continuous writing area 2 can be corrected with high accuracy overall. However, either area 3AU or 3B may be omitted.

The disk 1 having such a configuration is loaded into the recording/reproducing apparatus shown in FIG. 4, and information is written to or read from the continuous writing area 2 while being corrected using the data in the data recording areas 3A and 3B.

The recording/reproducing bag fil irradiates the disk l with the laser light from the semiconductor loop 12 via the half mirror 13, the filter 14, and the lens system 15. The reflected light from the disk l enters the half mirror 13 through the lens system 15 and the filter 14, is reflected by the half mirror 13, is applied to the photodetecting element 16, and is converted into an electrical reproduction signal S1.

The semiconductor laser 12 includes a light emitting element section 12A that generates a laser beam with a light intensity power corresponding to the output signal S2 of the light intensity power control circuit 17, and a light intensity monitoring element section 12B for monitoring the light intensity of the laser output. The light amount monitor output S3 is compared with the reference level output S4 in the comparison circuit 18, and the comparison output is given to the light amount power control circuit 17 as a control signal S5. The write data WD is transmitted to the light amount power control circuit 17 through the contact a1 of the switching circuit 19, which is controlled by the switching control signal Sll, to the light emission output S6.
and voltage source 20 through contact a2.
A continuous output RD having a constant voltage value is provided as a light emission output S6. This light emission output S6 is given to the light emitting element section 12A via the light amount power control circuit 17 and converted into laser light.

On the other hand, the reproduced signal S1 obtained by the photodetecting element 16 is given to the reproduced signal processing circuit 21, and the reproduced signal S1 read from the write/read area 2 of the disc I is reproduced.

That is, first, prior to writing or reading data to the continuous write area 2, the readout output RD is given to the light amount power control circuit 17, so that the data written in the data recording areas 3A and 3B of the disk l is (This is called program data PD) is extracted through the program data extraction port 22 and stored in the memory 23.

Here, the program data extracting circuit 22 calculates the optimum light amount power for writing and continuous output for each position in the radial direction of the write/read area 2 based on the reproduced program data, and stores the calculated data as program data PD in the memory 23. Send to.

The initial data thus stored in the memory 23 is
An address signal ADM obtained from the decoder 25 based on the address data ADD extracted from the reproduction signal S1 by the address extraction circuit 24 during the recording and reproduction mode.
and the switching control signal S11. That is, in the recording mode, the readout output RD is first obtained from the switching circuit 19, and the address data ADD at the position to be written is read from the disc 1 by the laser beam generated via the light amount power control circuit 17, and then the address data ADD is read out from the disk 1. The optimum light amount and power of the writing laser beam LW is read out from the memory 23 based on this, and is given as a setting signal S12 to the writing reference level setting circuit 26.

The write reference level setting circuit 26 consists of a controllable DC power supply,
When the laser beam scans the innermost portion of the disc 1 through the middle portion and the outermost portion of the disc 1 in accordance with the setting signal S12, the reference level output s4 of a value corresponding to the light amount power at the scanning position is switched accordingly. The signal is applied to the comparator circuit 18 via the contact b1 of the circuit 27. Then, a control signal S5 is sent from the comparator circuit 18 to cause the semiconductor laser 12 to generate a laser beam having an optimum write light amount and power PL (FIG. 1) depending on the scanning position of the disk 1.

On the other hand, in the reproduction mode, similarly to the recording mode, the readout output RD is first applied from the switching circuit 19 to the light amount power control circuit 17, and after sequentially outputting the address data ADD of the position to be reproduced, the memory Initial data regarding the scanning position, that is, data regarding the optimum light amount power at the innermost diameter portion, outermost diameter portion, and intermediate portion are read out from 23 and sent to the reference level setting circuit 28 as a setting signal S13.
give as. The successive reference level setting circuit 28 is a controllable voltage source, and provides its set output to the comparison circuit 18 through the successive side contact b2 of the switching circuit 27 as a reference level output S4. As a result, the comparator circuit 18 sends a control signal S5 corresponding to each reproduction scanning position 1 to the scene power such that the light amount power of the laser beam to be generated from the semiconductor laser 12 is set to the optimum readout light amount power P2 (FIG. 1). It is applied to the control circuit 1-7.

The switching circuits 19 and 27 are switched to the contact a1 and bl side in the recording mode and switched to the a2 and b2 side in the playback mode in response to the switching control signal Sll.

In the configuration shown in FIG. 4, when the recording/reproducing device 11 enters the recording mode, the switching control signal Sll temporarily switches the switching circuit 19 to the contact a2 side.

At this time, the semiconductor laser 2 enters a state in which it generates a laser beam with an intensity corresponding to the successive output RD via the switching circuit 19 and the light amount power control circuit 17, thereby reading out the data in the data recording area 3AI of the disc 1. It enters the initial scanning state. At this time, the data recording area 3A of disk 1
The initial data read from the disc 1 is input to the photodetector element 16 as reflected light from the disc 1, and the reproduced signal S
1, and the program data thus obtained is extracted by the program extraction circuit 22. Therefore, the memory 23 stores data representing the optimum light amount powers P1 and P2 at each radial position of the disk 1.

When the storage of the initial data in the memory 23 is completed in this way, the recording/reproducing device 11 is then switched to the write operation mode, and the switching circuit 19 is switched by the switching control signal Sll.
and 27 switches to the contacts a1 and b1. Therefore, the light amount power control circuit 17 is given the write data WD, and the comparison circuit 18 is given the reference level output S4 of the write reference level setting circuit 26. Here, the output of the write reference level setting circuit 26 is set to the memory 23 by the setting signal.
The laser beam sequentially scans the innermost portion, middle portion, and outermost portion of the writing/reading area 2 based on the initial data stored in the writing characteristic curve CW (Fig. 3). Standard level output S4 to obtain light amount power
Go ahead and change it.

In this way, the write data WD can be written in the continuous writing area 2 of the disc 1 with the strength of the optimum sight power P1.

On the other hand, when the recording and reproducing device 11 enters the reproducing mode,
As in the recording mode, first, the initial data reading operation state is temporarily entered, and the switching circuit 19 is switched to the contact a2 side by the switching control signal Sll, and the initial data is read from the data recording area 3AI of the disk 1. This is stored in the memory 23.

After that, when the recording/reproducing device 11 enters the read operation state, the switching circuits 19 and 27 are switched to the contact a2 by the switching control signal Sll.
and b.2 side, and provides the continuous output RD to the light amount power control circuit 17. The continuous reference level setting circuit 28 is controlled by the setting signal S13 obtained from the initial data stored in the memory 23, and the laser beam The control circuit controls the light amount power control circuit 17 so that the light amount power changes along the successive characteristic curve CR (FIG. 3) as it scans the innermost, intermediate, and outermost portions of the write/read area 2. A signal S5 is generated from the comparator circuit 18. By irradiating the read/write area 2 of the disk 1 with the read laser beam LR (FIG. 2) having the optimum light amount power P2, the information written in the continuous write area 2 is irradiated. It can be read without error.

FIG. 5 shows another example of how the disc 1 is used. In this case, the user uses the user data recording areas provided in the data recording areas 3AU and 3B to correct changes in the disc 1 over time. Correction data can be obtained.

There are the following problems regarding the aging of the disc 1.

In other words, the disk 1 has an amorphous recording film.
In this case, crystallization of the recording film tends to progress after a long period of time after manufacture. As such crystallization progresses, the threshold level for transitioning from an amorphous state to a crystalline state decreases.

If this phenomenon is not corrected and the readout laser beam of the initially set intensity is irradiated onto the disk 1, the intensity of the readout laser beam will exceed the threshold and the recorded portion of the recording film will be crystallized and the recorded data will be lost. There is a risk that it will disappear. The embodiment shown in FIG. 5 is intended to effectively avoid such a possibility.

In FIG. 5, in which parts corresponding to those in FIG. the switching circuit 34 through the switching circuit 33
give to The switching circuit 34 is provided in the signal path of the control signal S5 from the comparison circuit 18 (FIG. 4) to the light amount power control circuit 17.

When using the user correction circuit 31, the switching circuit 34
By switching from the contact C1 side to the C2 side, the control signal 521 generated in the user correction circuit 31 can be used as a control signal for the light amount power control circuit 17.

The user correction circuit 31 has a comparison circuit 36 that receives the write data WD via the memory 35 as one comparison input,
This write data WD is compared with the reproduced data PBD obtained in the reproduced signal processing circuit 21, and when they match, a coincidence detection output DT is sent out. The coincidence detection signal DT is applied to the switch circuit 33, and the switch circuit 33 is controlled to be switched from an on state to an off state by the coincidence detection signal DT.

On the other hand, the control signal 321 passes through the memory content correction circuit 3 through the switch circuit 37 which is turned on in response to the coincidence detection signal DT.
8 and stored in the memory 23, the correction data SH is made up of the signal level of the control signal S21 when the switch circuit 37 is turned on.

At this time, the control voltage generation circuit 32 receives the coincidence detection signal DT and is controlled to maintain the signal level of the control signal S21.

In the user correction circuit 31 having the configuration shown in FIG. 5, test write data WD is first applied to the light amount power control circuit 17 through the switching circuit 19. At this time, the laser light obtained from the light emitting element section 12A is irradiated onto the data recording areas 3AU and 3B prepared at the inner and outer circumferential parts of the disc 1, and test data WD is written in the data recording areas 3AU and 3B.

After that, when the state is switched to the playback operation state, the switching circuit 19 switches to the contact a2 side, so that the data recording area 3AU
and 3B are irradiated with successive laser beams whose intensity changes according to the sawtooth wave-like changes in the control signal 321, thereby reading test data, which is then outputted from the reproduction signal processing circuit 21 as reproduction output data PBD. The signal is applied to the comparison circuit 36.

By the way, the test data WD written in the data recording areas 3AU and 3B and the reproduced data PBD can match each other by reading the test data from the disk 1, which has undergone crystallization due to changes over time, without error. This occurs when the readout laser beam with the minimum intensity possible is obtained.

Therefore, when the data taken into the memory content correction circuit 37 when the coincidence detection signal DT is obtained is stored in the memory 23 as the correction data SH, the contents are transferred to the write/read area 2 of the disk 1 which has undergone changes over time. It represents the optimum light amount and power of the read laser beam used when reading written data.

The correction data SH stored in the memory 23 is used to correct the light amount and power of the read laser beam used when reading information from the continuous writing area 2 of the disk 1, as described above with reference to FIG. Thus, if the recording film of the disk 1 changes over time, writing and continuous output can be performed with the optimum light amount and power that adapts to the change.

In this way, it is possible to provide high adaptability to changes in the disc 1 over time, and therefore information can be written to and read from the disc 1 with a sufficiently low error rate.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to adaptively control the light amount and power of the writing laser beam and the reading laser beam for the continuous writing area of the recording/reproducing disk according to the position in the radial direction of the disk. A recording and reproducing device that can further improve the reliability of reading and writing operations can be easily realized.

Therefore, by using the user correction circuit 31 described above with reference to FIG. 5, it is possible to easily obtain a recording/reproducing apparatus that can be applied to changes over time in the recording film of a recording/reproducing disk.

[Brief explanation of the drawing]

FIG. 1 is a route map showing a recording/reproducing disk according to the present invention;
Fig. 2 is a characteristic curve diagram showing the writing laser beam and reading laser beam, Fig. 3 is a characteristic curve diagram showing the relationship between the disk diameter and the light amount power, and Fig. 4 is a characteristic curve diagram showing the relationship between the disk diameter and the light amount power. Block diagram showing one embodiment of the recording/reproducing device, No. 5
The figure is a block diagram showing a recording/reproducing apparatus in another embodiment. 1...Recording/reproducing disk, 2...Writing/reading area, 3A, 3B...Data recording area, 1
1...Recording/reproducing device, 12...Semiconductor laser, 13...Half mirror 116...
...Photodetection element, 17...Light amount power control circuit, 1B...Comparison circuit, 21...Reproduction signal processing circuit, 22...Program data extraction Circuit, 23...Memory, 24...Address extraction circuit, 25...Decoder, 26.28.
...Writing and reading reference level setting circuit, 31...
...User correction circuit.

Claims (1)

[Claims] 1. In an optically recordable and playable recording/playback disc, a data recording area in which initial data regarding the optimum light amount power for recording and playback at a predetermined position in the radial direction at the time of manufacture is formed on the inner circumference. A recording/playback disc characterized by recording in the form of pits. 2. In the method for recording information on a recording/reproducing disk or reproducing information from the recording/reproducing disk described in claim 1, the method comprises: reproducing initial data recorded on the inner circumferential portion of the disk; , the reproduced data is held by the holding means, the held data is sequentially read out according to the radial position of recording or reproduction scanning, and the light amount power of the reproduction light is controlled based on the read data. A recording and reproducing method characterized by the following.