JPH07254157A - Optical disk device - Google Patents

Abstract

(57) [Summary] [Object] In an optical disc having a read-only ROM area and a writable RAM area within one optical disc area, a track at a target address can be stably accessed, and stable focus and To provide an optical disk device capable of realizing tracking servo. A servo system switching signal C is generated by the pit signal detection circuit 8 and the servo system switching signal generation circuit 9, and when the pit signal is not included in the reproduction signal, the polarity of the servo system switching signal, the gain, and In addition to changing the gain of the focus servo signal, a track jump signal is generated from the 1/2 track jump circuit 12 to accelerate and decelerate the light spot in the disk radial direction.

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 for recording / reproducing an information signal on / from an optical disk having a recordable area made of an optical information recording medium and a read-only area.

[0002]

2. Description of the Related Art Recently, a read-only area (hereinafter referred to as RO
There has been proposed an optical disc having a M area) and a recordable area (hereinafter referred to as a RAM area) in which an information signal can be newly added or rewritten. An optical disc of this type using a magneto-optical film which is an alloy of a transition metal and a rare earth metal as an optical information recording medium in the RAM area is disclosed in, for example, Japanese Patent Laid-Open No. 2-239440. 6 and 7 are diagrams showing a schematic configuration of an optical disc according to the above-mentioned prior application, FIG. 6 is a configuration diagram showing an arrangement of a ROM area and a RAM area, and FIG. 7 is a sectional view of the optical disc of FIG. 6 cut in the plate thickness direction. FIG. FIG. 8 is a diagram showing a configuration of a conventional optical disc device using this optical disc.

In FIG. 6, reference numeral 100 denotes an optical disk, 10
Reference numeral 1 is a RAM area, and 102 is a ROM area. As shown in the figure, the ROM area 102 is provided in the inner peripheral portion of the optical disc 100, and the RAM area 101 is provided in the outer peripheral portion of the optical disc 100. This makes it possible to realize a convenient large-capacity file optical disk as compared with a read-only optical disk (compact disk or the like).

In this optical disc 100, as shown in FIG. 7, the RAM area 101 accurately reflects a light spot emitted from an optical head on an information signal train (hereinafter referred to as an information track) in the disc radial direction. It has a guide groove 104 for so-called tracking which is aligned with. The information signal to be additionally recorded is the guide groove 1
A signal domain (not shown) due to a difference in magnetic direction is recorded on the magneto-optical film 04. As a result, while the information signal is recorded on the guide groove 104, the signal quality of the information signal is improved. Further, an identification signal for identifying the position of the information track, the recording information position in the information track, or the like is also recorded in advance as the uneven pit 105 between the guide grooves 104. On the other hand, in the ROM area 102, there is no tracking guide groove 104 in the RAM area 101, and an information signal is recorded in advance by the uneven pits 103.

The optical disc 100 having the above-mentioned structure is recorded / recorded.
In the optical disk device for reproduction, as shown in FIG. 8, the focus error signal detected by the optical head 1 is input to the focus servo circuit 2 and subjected to processing such as phase compensation for stabilizing the servo system. . The output of the focus servo circuit 2 is controlled by driving a focus actuator (not shown) mounted on the optical head 1 via a drive amplifier 3 so that the light spot is focused on the recording surface of the optical disc 100. Is done. Similarly, the tracking error signal detected by the optical head 1 is input to one input terminal of the switch 5 and also to the inverting amplifier 4. The output of the inverting amplifier 4 is the switch 5
Is input to the other input terminal of. Switch 5 is RAM
The input signal is selected based on the access control signal for accessing the area 101 or the ROM area 102, and the polarity of the signal input to the tracking servo circuit 6 is switched. In the tracking servo circuit 6, processing such as phase compensation for stabilizing the servo system is performed. The output of the tracking servo circuit 6 drives a tracking actuator (not shown) mounted on the optical head 1 via a drive amplifier 7 so that a light spot is generated between the guide grooves 104 of the optical disc 100 or the recording pit 103. Tracking control is performed so as to follow.

[0006]

By the way, the optical disk 10 in which the RAM area 101 and the ROM area 102 are mixed.
When 0 is used, when the vicinity of the boundary between the RAM area 101 and the ROM area 102 is accessed, the accuracy of the seek causes
ROM despite accessing RAM area 101
The seek may end in the area 102, or the seek may end in the RAM area 101 even though the ROM area 102 is accessed. In the above conventional device, the polarity of the signal input to the tracking servo circuit 6 is switched based on the access control signal for accessing the RAM area 101 or the ROM area 102. If the seek ends in an area different from the accessed area, the polarity of the signal will be opposite to the correct polarity. In this case, since the light spot follows the track to be originally reproduced, it is possible to reproduce the identification signal for identifying the recorded information position in the information track in which the track information is recorded. Therefore, there arises a problem that the subsequent operations are disabled.

In the RAM area 101, the light spot follows the tracking guide groove 104, whereas the ROM area 102 follows the concave and convex pits 103.
As compared with the area 101, the focus error signal level is lowered and the characteristics of the focus servo system are deteriorated. Furthermore, regarding the tracking error signal, R
In the OM area 102, since the tracking error signal is obtained only in the pit portion, the tracking error signal level is lower than that in the RAM area 101, and there is a problem that the characteristics of the tracking servo system are deteriorated.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide an optical disk device suitable for using an optical disk having a ROM area and a RAM area.

[0009]

To achieve the above object, in the optical disk device of the present invention, the pit 105
As a pit signal detection result, a pit signal detecting means for detecting the presence or absence of an identification signal for identifying a recorded information position or the like in a previously recorded information track or an information signal prerecorded by the pit 103 is provided. Based on this, when the servo system switching signal is generated and the signal recorded in advance by the pit is not included in the reproduction signal, the polarity of the tracking servo signal is changed and the light spot is accelerated and decelerated in the disk radial direction. Therefore, the drive signal is applied to the tracking actuator.

As another means, the RAM area and the RO
When accessing near the boundary of the M area, even if the seek end track is deviated due to the accuracy of seek, when the RAM area is accessed, the seek always ends in the RAM area, and when the ROM area is accessed. The seek track position is adjusted in advance so that the seek always ends in the ROM area, and after the seek, the light spot is surely positioned on the track of the target address by a track jump or the like, so that the access is performed.

Further, by the servo system switching signal, R
The focus and tracking servo system gains are switched between the AM area and the ROM area.

[0012]

When the seek is completed in a region other than the accessed region, the guide groove 10 for tracking is used.
4 or the light spot follows between the tracks on which the pits 103 are formed.
The identification signal for identifying the recorded information position in the information track pre-recorded as 05, or the pit 10
3 makes it impossible to obtain a prerecorded information signal. Therefore, by detecting the presence or absence of the identification signal or the information signal recorded in advance as a pit from the reproduction signal, it is possible to determine whether or not the light spot correctly follows the track. Therefore, the servo system switching signal is generated based on this detection result, and when the reproduction signal from the pit is not included, the polarity of the servo signal is changed to the correct polarity by changing the polarity of the tracking servo signal. The light spot can follow the track to be reproduced. After that, the identification signal can be reproduced, and processing such as accessing the track of the target address again can be performed. Further, when switching the polarity of the tracking servo signal, by applying a drive signal for accelerating and decelerating the light spot in the disk radial direction to the tracking actuator, the light spot can be stably moved to the track to be originally reproduced. it can.

As another method, by adjusting the number of tracks to seek in advance so that the seek always ends in the accessed area, the polarity of the tracking error signal after the end of seek always becomes the correct polarity. Since the light spot can follow the track to be reproduced and the identification signal recording the track information can be reproduced, the light spot can be reliably positioned on the track of the target address by a track jump or the like thereafter. .

Further, by the servo system switching signal, R
By switching the gain of the focus and tracking servo system between the AM area and the ROM area, the gain of the focus and tracking servo system can be made substantially constant in the RAM area and the ROM area, and the servo system can be stabilized. .

As described above, the optical disk device of the present invention can surely access the track of the target address in the optical disk having the ROM area and the RAM area, and can perform the focus and tracking servo stably. I can.

[0016]

The present invention will be described in detail below with reference to the illustrated embodiments. FIG. 1 is a block diagram showing the configuration of an optical disk device according to the first embodiment of the present invention. In FIG. 1, 1 is an optical head, 2 is a focus servo circuit, 3 is a drive amplifier, 4 is an inverting amplifier, 5 is a switch, 6 is a tracking servo circuit, 7 is a drive amplifier, 8 is a pit signal detection circuit, and 9 is a servo. A system switching signal generation circuit, 10 is an amplifier, 11 is a switch, 12 is a 1/2 track jump circuit, 13 is an addition circuit, and 100 is an optical disk having the configuration shown in FIGS.

In the configuration shown in FIG. 1, the reproduction signal A from the optical head 1 is input to the pit signal detection circuit 8. The pit signal detection circuit 8 detects whether or not the reproduction signal A includes a reproduction signal from the pit. If the reproduction signal A includes a reproduction signal from the pit, the reproduction signal from the pit at the “H” level is included. If not, the discrimination signal B of "L" level is output to the servo system switching signal generation circuit 9. In the servo system switching signal generation circuit 9, the ROM area 102 is controlled by the access control signal at the start of access.
The servo system switching signal C is set to the “L” level when accessing the RAM, and the servo system switching signal C is set to the “H” level when accessing the RAM area 101. Further, when the discrimination signal B is at the "L" level for a predetermined time or more, that is, when the discrimination signal B is at the "L" level for a repetition period of the identification signal or more, the servo system switching signal generation circuit 9 It is determined that the light spot does not follow the original track, the level of the servo system switching signal C is inverted, and this is output to the switch 11, the switch 5 and the 1/2 track jump circuit 12. .

The focus error signal from the optical head 1 is input to one input terminal 11-a of the switch 11,
The amplifier 1 is connected to the other input terminal 11-b of the switch 11.
A focus error signal amplified by a predetermined amount Gf by 0 is input. In the switch 11, for example, when the level of the servo system switching signal C is “L”, the input terminal 1
The signal input to 1-b is output, and when the level of the signal C is "H", the signal input to the input terminal 11-a is output. The output of the switch 11 is input to the drive amplifier 3 after being subjected to processing such as phase compensation for stabilizing the servo system in the focus servo circuit 2. In the drive amplifier 3, the focus servo circuit 2
The focus actuator mounted on the optical head 1 is driven based on the output of the. As a result, control is performed so that the light spot is focused on the recording surface of the optical disc 100.

Further, one input terminal 5-a of the switch 5 is
Is input with the tracking error signal from the optical head 1, and the other input terminal 5-b of the switch 5 is input with the tracking error signal which is amplified by the inverting amplifier 4 by a predetermined amount Gt and whose polarity is inverted. It In the switch 5, for example, when the level of the servo system switching signal C is "L", the signal input to the input terminal 5-b is output,
When the level of the signal C is "H", the signal input to the input terminal 5-a is output. The output of the switch 5 is input to the drive amplifier 7 via the adder circuit 13 after being subjected to processing such as phase compensation for stabilizing the servo system in the tracking servo circuit 6. The drive amplifier 7 drives the tracking actuator mounted on the optical head 1 based on the output of the tracking servo circuit 6. As a result, control is performed so that the light spot follows the track of the optical disc 100.

The 1/2 track jump circuit 12 outputs the track jump signal E for moving the optical spot in the disk radial direction at the time when the level of the servo system switching signal C changes, and the track jump signal E While being output, the “H” level hold signal G is output to the tracking servo circuit 6. The track jump signal E is input to the drive amplifier 7 via the adder circuit 13. Further, in the tracking servo circuit 6, the low frequency component of the servo signal immediately before or immediately after the track jump signal E is output is held while the hold signal G is “H” and is output to the adder circuit 13. There is. In the drive amplifier 7, the tracking servo circuit 6
The tracking actuator mounted on the optical head 1 is driven based on the output F from the track jump signal E and the track jump signal E from the 1/2 track jump circuit 12. As a result, the light spot moves by 1/2 track in the disk radial direction.

Next, the operation of this embodiment will be further described with reference to the operation waveforms of FIG. FIG. 2 corresponds to the case where the seek is completed in the RAM area 101 when the ROM area 102 is accessed, and shows the case where the light spot 200 follows the guide groove 104 for tracking after the seek is completed. 2 (1) shows an optical disc on which an array of concave and convex recording pits 103 in the ROM area 102 is formed at a position displaced by 1/2 track with respect to the extension line of the guide groove 104 in the RAM area 101. 3 shows the relationship between the track and the locus of the light spot 200. In addition, (2) of FIG. 2 shows a case where the concave and convex recording pit 103 rows in the ROM area 102 are formed on the extension line of the guide groove 104 in the RAM area 101.
The relationship between the track on the optical disk and the locus of the light spot 200 is shown.

As shown in FIG. 2C, the light spot 2
00 is a concave continuous guide groove 104
, The level of the reproduction signal is low and the high frequency signal from the pit 105 portion is not included. Therefore, in the pit signal detection circuit 8, since the reproduction signal A does not include the high frequency signal from the pit portion, the discrimination signal B of "L" level is generated.
Is output. In the servo system switching signal generation circuit 9, the target R
Although the servo system switching signal C of "L" level indicating the OM area 102 is output, when the discrimination signal B is "L" level, it is determined that the light spot does not follow the original track. , And inverts the level of the servo system switching signal C, and outputs an "H" level signal indicating the RAM area (time t1).

The "H" level servo system switching signal C is input to the switch 11, the switch 5 and the 1/2 track jump circuit 12. This allows the switch 1
At 1, the signal input to the input terminal 11-a is selected,
The switch 5 selects the signal input to the input terminal 5-a and outputs it to the servo circuits 2 and 6. The 1/2 track jump circuit 12 outputs the track jump signal E for accelerating the light spot 200 in the disk radial direction at the time t1 when the level of the servo system switching signal C changes, and also outputs the track jump signal E. During this period, the hold signal G of "H" level is output to the tracking servo circuit 6. 1/2
The tracking error signal D is input to the track jump circuit 12, the light spot 200 is moved by approximately 1/4 track, and the time t2 at which the tracking error signal D reaches a substantially maximum level is detected, and the light spot 200 is detected. A track jump signal E having the opposite polarity to that at the time of acceleration is output to reduce the moving speed of the. Same time as acceleration (t2-t1)
Then, the track jump signal E for deceleration is output, and at a time point t3 when the light spot 200 moves by about 1/2 track and reaches the middle of the guide groove 104, the track jump signal E is set to 0 level. Then, the hold signal G is set to the “L” level.

After that, the light spot 200 is subjected to tracking control based on the tracking error signal selected by the switch 5. As a result, the light spot 200 follows the original track position between the guide grooves 104 for tracking, and the reproduction signal A is a high frequency signal indicating a reproduction signal from the pit 105 which is previously formed as a pit as an identification signal. Signal will be reproduced. Therefore, the pit signal detection circuit 8 outputs the "H" level determination signal B. In the servo system switching signal generation circuit 8, when the discrimination signal B is at “H” level, it is determined that the light spot 200 follows the original track, and the level of the servo system switching signal C is not inverted, An "H" level signal indicating the RAM area 101 is output.

FIG. 3 corresponds to a case where the seek is completed in the ROM area 102 when the RAM area 101 is accessed, and the light spot 200 is located between the tracks composed of the concave and convex recording pits 103 after the seek is completed. The case of following is shown. In (1) of FIG. 3, a row of concave and convex recording pits 103 in the ROM area 102 is 1 with respect to an extension line of the guide groove 104 in the RAM area 101.
2 shows the relationship between the track on the optical disk and the locus of the light spot 200 when it is formed at a position shifted by / 2 track. Further, (2) of FIG. 3 shows a track and an optical spot 2 on the optical disc when the concave and convex recording pit 103 rows in the ROM area 102 are formed on the extension line of the guide groove 104 in the RAM area 101.
The relationship of the loci of 00 is shown.

As shown in FIG. 3C, the light spot 2
When 00 is following between tracks composed of a row of concave and convex recording pits 103, the amount of reflected light is large, the level of the reproduction signal is large, and the high frequency signal from the pits 103 is not included. . Therefore, the pit signal detection circuit 8 outputs the discrimination signal B of "L" level because the reproduction signal A does not include the high frequency signal from the pit portion. The servo system switching signal generation circuit 9 outputs an "H" level servo system switching signal C indicating the target RAM area 101 at the end of the seek by the access control signal, but the discrimination signal B is at the "L" level. In this case, it is determined that the light spot does not follow the original track, the level of the servo system switching signal C is inverted, and "L" indicating the ROM area 102 is shown.
A level signal is output (time t1).

The "L" level servo system switching signal C is input to the switch 11, the switch 5 and the 1/2 track jump circuit 12. This allows the switch 1
At 1, the signal input to the input terminal 11-b is selected,
The switch 5 selects the signal input to the input terminal 5-b and outputs it to the servo circuits 2 and 6. The 1/2 track jump circuit 12 outputs the track jump signal E for accelerating the light spot 200 in the disk radial direction at the time t1 when the level of the servo system switching signal C changes, and also outputs the track jump signal E. During this period, the hold signal G of "H" level is output to the tracking servo circuit 6. 1/2
The tracking error signal D is input to the track jump circuit 12, the light spot 200 is moved by approximately 1/4 track, and the time t2 at which the tracking error signal D reaches a substantially maximum level is detected, and the light spot 200 is detected. A track jump signal E having the opposite polarity to that at the time of acceleration is output to reduce the moving speed of the. Same time as acceleration (t2-t1)
Then, the track jump signal E for deceleration is output, and the light spot 200 moves by about 1/2 track to reach the track composed of the recording pit 103 rows at time t3, and the track jump signal E is set to 0 level. The hold signal G is set to "L" level.

After that, the light spot 200 is subjected to tracking control based on the tracking error signal selected by the switch 5. As a result, the light spot 2
00 follows the original track position consisting of a row of concave and convex recording pits 103, and the reproduction signal A is a high-frequency signal representing a reproduction signal from the pit 103 which is previously formed as an information signal. become. Therefore,
The pit signal detection circuit 8 outputs the "H" level determination signal B. In the servo system switching signal generation circuit 9, when the discrimination signal B is at the “H” level, it is determined that the light spot 200 follows the original track, and the level of the servo system switching signal C is not inverted, R
An "L" level signal indicating the OM area 102 is output.

FIG. 4 is a block diagram showing the configuration of an optical disk device according to the second embodiment of the present invention. In FIG. 4, the same parts as those in the first embodiment of FIG. is there. In FIG. 4, 14 is an address reproducing circuit, and 15
Is a target seek position setting circuit, 16 is a light spot position detection circuit, 17 is a seek control circuit, and 18 is a drive amplifier.

In the configuration shown in FIG. 4, the reproduction signal A from the optical head 1 is input to the address reproduction circuit 14. The address reproducing circuit 14 detects the address of the track followed by the light spot from the identification signal formed in advance with the pit and outputs it to the target seek position setting circuit 15. A target address signal is input from a controller (not shown) to the target seek position setting circuit 15, and the target seek address and the target seek address are input based on the current address and the target address to be accessed, which are input from the address reproducing circuit 14. The servo system switching signal is set, the target seek address is output to the seek control circuit 17, and the servo system switching signal C is output to the switches 5 and 11, respectively.

The light spot position detection circuit 16 detects the position of the light spot in the disk radial direction at the time of seek by counting the number of sine waves output each time the light spot moves one track on a track. To do. The seek control circuit 17 outputs a seek control signal based on the target seek address input from the target seek position setting circuit 15 and the light spot position input from the light spot position detection circuit 16. The seek control signal output from the seek control circuit 17 is the drive amplifier 1
A linear motor (not shown) equipped with the optical head 1 is driven via 8 in the radial direction of the disk to position the light spot at the target seek address.

FIG. 5 shows an example of setting the target seek address and the servo system switching signal in the target seek position setting circuit 15 described above.

In the seek position setting circuit 15, first, the target address Nt is read from the controller (step ST
1) The difference ΔNt between the target address Nt and the address Nro of the outermost circumference of the ROM area which has been input in advance is ΔNt.
= Nro-Nt is calculated (step ST
2). Next, this difference ΔNt is compared with a predetermined value No. If the difference ΔNt ≧ No (Y in step ST3)
(In the case of ES), the target address is located sufficiently inside the outermost position of the ROM area, and even if the seek end position is shifted due to the position detection accuracy of the light spot position detection circuit 16 at the time of seek. , It is determined that the seek end position is inside the outermost position of the ROM area, and the target address Nt is set as the target seek address Ns (step ST
4). Since the seek end position is in the ROM area, the servo system switching signal C is set to the "L" level (step ST5).

As a result of comparing the difference ΔNt with the predetermined value No, if No> ΔNt ≧ 0 (step ST
6 is YES), the target address is in the ROM area but near the outermost peripheral position of the ROM area, and the seek end position is deviated due to the position detection accuracy of the light spot position detection circuit 16 at the time of seek. , Seek end position is RAM
The target address Nt-No is set as the target seek address Ns so that the seek end position is always within the outermost peripheral position of the ROM area (step ST7). Since the seek end position is in the ROM area, the servo system switching signal C is set to the "L" level (step ST8).

As a result of comparing the difference ΔNt with the predetermined value No, if 0 ≧ ΔNt> -No (step S
If T9 is YES), the target address is in the RAM area but near the outermost peripheral position of the ROM area, and the seek end position is displaced due to the position detection accuracy of the light spot position detection circuit 16 at the time of seek. , Seek end position is RO
The target address Nt + No is determined to be the target seek address Ns so that the seek end position is surely in the RAM area (step ST10).
Since the seek end position is in the RAM area, the servo system switching signal C is set to the "H" level (step ST11).

Further, as a result of comparing the difference ΔNt with a predetermined value No, if −No ≧ ΔNt (step ST
9 (NO in 9)), the target address is at a position sufficiently outer than the outermost position of the ROM area, and the seek end position deviates due to the position detection accuracy of the light spot position detection circuit 16 at the time of seek. Also, the seek end position is determined to be in the RAM area outside the outermost circumference position of the ROM area, and the target address Nt is set as the target seek address Ns (step ST12). The seek end position is RAM
Servo system switching signal C becomes "H"
The level is set (step ST13).

By setting the target seek address Ns as described above, even if the seek end position is deviated due to the position detection accuracy of the light spot position detection circuit 16 at the time of seek, the seek end position is always the target address. The light spot can follow the correct track position by setting the servo system switching signal correctly within the same area. As a result, the track identification signal can be reproduced after the end of the seek, and the track can be positioned on the track of the target address thereafter by processing such as track jump.

Here, in the description of the present embodiment, an example in which the tracking error signal is used as the position detection method of the light spot position detection circuit 16 has been described, but the present invention is not limited to this, and other sensors such as a sensor provided in the linear motor may be used. It may be a detection method. Further, in the description of FIG. 5, when comparing the difference ΔNt with the predetermined value No, No is not a fixed value,
Depending on the difference between the current reproduction address input from the address reproduction circuit 14 and the target address Nt, No is increased when the difference is large, and No is decreased when the difference is small. Is also good. Also, FIG.
The explanation of the flow of FIG.
02 corresponds to the case where the RAM area 101 is located on the inner circumference and the RAM area 101 is located on the outer circumference, and the address of the track increases from the inner circumference to the outer circumference. However, the present invention is not limited to this. In this case, the target seek address Ns is set so that the seek end position is always in the same area as the target address.
Should be set.

As described in detail above, by using the optical disk device of the present invention, it is possible to stably access the track of the target address in the optical disk having the RAM area and the ROM area. RAM area and R
It is possible to realize stable focus and tracking servo with little gain variation in the OM region.

[0040]

As described above, according to the present invention, a track at a target address can be stably accessed in an optical disc having a read-only ROM area and a writable RAM area in one optical disc area. Therefore, stable focus and tracking servo can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an optical disk device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a light spot of R in the first embodiment of the present invention.
It is explanatory drawing which shows the locus | trajectory and operation waveform of a light spot when it is located in an AM area.

FIG. 3 is a schematic diagram of the first embodiment of the present invention in which the light spot is R
It is explanatory drawing which shows the locus | trajectory and operation waveform of a light spot when it is located in an OM area.

FIG. 4 is a block diagram showing a configuration of an optical disc device according to a second embodiment of the present invention.

FIG. 5 shows an optical disk device according to a second embodiment of the present invention.
It is a flowchart figure which shows the setting processing flow of a target seek address and a polarity switching signal.

FIG. 6 is an explanatory diagram showing an arrangement configuration of an optical disc having a ROM area and a RAM area.

FIG. 7 is an explanatory diagram showing a main configuration of the optical disc of FIG.

FIG. 8 is a block diagram showing a configuration of a conventional optical disc device using an optical disc having a ROM area and a RAM area.

[Explanation of symbols]

 1 Optical head 8 Pit signal detection circuit 9 Servo system switching signal generation circuit 12 1/2 track jump circuit 13 Adder circuit 14 Address reproduction circuit 15 Target seek position setting circuit 16 Optical spot position detection circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toru Sasaki Toru Sasaki 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside the Visual Media Research Laboratory, Hitachi, Ltd. (72) Inventor Naoki Mori 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. Visual Media Research Center

Claims (5)

[Claims] 1. A transmissive substrate having at least a recordable optical information recording medium, and having a read-only area and a recordable area on the same surface of the substrate, wherein the read-only area has concave and convex pits. The first information signal is recorded in advance by the arrangement of No. 2, the recordable area has guide grooves formed of concavities and convexities, and the second information signal (additional signal) is recorded between the guide grooves, and the address signal ( An optical head for irradiating the optical disc with a light spot and reproducing or recording information from the optical disc using an optical disc on which a third information signal such as an identification signal) is provided in advance by an array of concave and convex pits, and the optical disc. Focus control means for controlling the focus state of the light spot on the recording surface of the optical disc based on the focus error signal output from the head, and tracking error output from the optical head. In an optical disc device having a tracking control means for controlling a light spot to follow a track on the optical disc based on a signal, it is determined whether the light spot is located in the reproduction-only area or the recordable area. An optical disk device, characterized in that an area discriminating means for discriminating is provided and the gain of the focus control means, the gain of the tracking control means and the polarity of a signal are switched based on the output of the area discriminating means. 2. A recordable optical information recording medium is provided on a transparent substrate, and a read-only area and a recordable area are provided on the same surface of the substrate, and the read-only area is an uneven pit. The first information signal is recorded in advance by the arrangement of No. 2, the recordable area has guide grooves formed of concavities and convexities, and the second information signal (additional signal) is recorded between the guide grooves, and the address signal ( An optical head for irradiating the optical disc with a light spot and reproducing or recording information from the optical disc using an optical disc on which a third information signal such as an identification signal) is provided in advance by an array of concave and convex pits, and the optical disc. Focus control means for controlling the focus state of the light spot on the recording surface of the optical disc based on the focus error signal output from the head, and tracking error output from the optical head. In an optical disc device having a tracking control means for controlling a light spot to follow a track on the optical disc based on a signal, it is determined whether the light spot is located in the reproduction-only area or the recordable area. An area discriminating means for discriminating and a track jump means for moving the light spot in the radial direction of the disk by about 1/2 track pitch are provided, and the light spot is discriminated by about 1 / n based on the output of the area discriminating means. An optical disk device characterized in that it is moved in the radial direction of the disk by two track pitches. 3. The area information discriminating device according to claim 1, wherein the first information signal is formed by an array of concave and convex pits of the optical disk or an address signal (identification is formed in advance by an array of concave and convex pits. The optical disc device is characterized in that the area is discriminated by whether or not the third information signal such as a signal) is included in the reproduction signal from the optical head. 4. A recordable optical information recording medium is provided at least on a transparent substrate, and a read-only area and a recordable area are provided on the same surface of the substrate, and the read-only area is an uneven pit. The first information signal is recorded in advance by the arrangement of No. 2, the recordable area has guide grooves formed of concavities and convexities, and the second information signal (additional signal) is recorded between the guide grooves, and the address signal ( An optical head for irradiating the optical disc with a light spot and reproducing or recording information from the optical disc using an optical disc on which a third information signal such as an identification signal) is provided in advance by an array of concave and convex pits, and the optical disc. Focus control means for controlling the focus state of the light spot on the recording surface of the optical disc based on the focus error signal output from the head, and tracking error output from the optical head. Tracking control means for controlling the light spot to follow the track on the optical disc based on the signal, and for moving the optical spot in the radial direction of the optical disc by moving the optical head in the radial direction of the optical disc. Transporting means and position detecting means for detecting the position of the light spot in the radial direction of the optical disc,
Position setting means for designating the position of the light spot in the radial direction of the optical disk, and transfer for driving the transfer means based on the outputs of the position detecting means and the position setting means to position the light spot on a target track. In an optical disc device having a control means, when the target track is near the boundary between the read-only area and the recordable area, the position setting means is provided with a position deviated from the position of the target track by a predetermined amount N. An optical disk device characterized by being set. 5. The optical disk device according to claim 4, wherein the predetermined amount N is changed according to the difference between the current position of the light spot in the disk radial direction and the position of the target track. .