JPH05159491A - Track jump controller - Google Patents

Abstract

PURPOSE:To improve the reliability of access operation to a disk shape recording medium having plural data areas with different, recording and reproducing frequency. CONSTITUTION:A second timing signal TS2 hold-jumping an optical head 8 on the half way of the track is generated based on a first timing signal TS1 generated based on the detection of the ID part of the final sector of the track. The second timing signal TS2 is generated by delaying the first timing signal TS1 for a prescribed time by a counter circuit 21. A timing switching signal is outputted to a jump timing generating circuit 15 by a controller 16 when the optical head 8 is moved between different zones on a disk 17 corresponding to an M-CAV system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an M-CAV for a disk-shaped recording medium having recording tracks formed in a spiral shape.
The present invention relates to a recording / reproducing apparatus for performing recording / reproducing by a (Modified Constant Angular Velocity) method, and particularly, for each rotation of a disk-shaped recording medium, the recording / reproducing head is jumped to the inner peripheral side of one track and the recording / reproducing head is arranged on the same track. The present invention relates to a track jump control device for holding.

[0002]

2. Description of the Related Art The M-CAV system rotates a disc-shaped recording medium at a constant angular velocity to increase the recording / reproducing frequency in multiple steps from the inner peripheral side to the outer peripheral side of the disc-shaped recording medium. This is a control method that tries to keep the linear recording density almost constant. The M-CAV method has an advantage that the recording capacity of the disk-shaped recording medium can be increased while using a simple rotation control system.

A disc-shaped recording medium compatible with the M-CAV system is divided into a plurality of data areas (hereinafter referred to as zones) according to the radial position. The recording / reproducing frequency is set within a certain allowable range for each zone, and normal recording / reproducing becomes difficult at frequencies other than the set recording / reproducing frequency.

Here, the above disk-shaped recording medium includes
It is assumed that the recording track is formed in a spiral shape, and one turn of the recording track is one track. One track is further divided into areas called sectors, in which one unit of data is recorded. At the head of each sector, there is an ID portion in which address information indicating which track and which sector the sector belongs to is recorded.

The recording / reproducing apparatus compatible with the disc-shaped recording medium as described above controls the recording / reproducing head to stay on the same track while the recording / reproducing operation is on standby.
That is, the position of the final sector is known by reproducing the ID portion, and immediately after the final sector is detected, the recording / reproducing head is caused to make a track jump to the inner circumference side of one track (hereinafter referred to as a hold jump). Therefore, one hold jump is performed by one rotation of the disc-shaped recording medium.

By the way, when the recording / reproducing head is moved from the zone including the track currently undergoing the hold jump to a predetermined track included in a different zone, the ID portion and the data of the target track can be read normally.
Immediately before moving, access control is performed after switching to the recording / reproducing frequency corresponding to the destination zone. In order to determine whether or not the target track has been reached and to know the position of the last sector where the hold jump is performed, it is necessary to reproduce the ID portion and obtain the address information immediately after performing the access control.

Generally, the access control is a combination of a rough search using a linear motor or the like and a fine search including a track jump using a tracking actuator or the like. In recent years, the accuracy of the rough search has been remarkably improved by the track counting technique and the like, but still some errors may occur due to miscounting.

[0008]

However, if an error occurs in the rough search, when the target track is located near the boundary between two different zones, the track in the zone which does not correspond to the recording / reproducing frequency switched in advance is detected. May reach. In this case, since the recording / reproducing frequency does not match, the ID portion of the arrived track cannot be normally reproduced, and thus the problem that the address information cannot be obtained occurs.

The object of the present invention is to improve the probability that the address information of the target track can be obtained even when the track of the zone which does not correspond to the recording / reproducing frequency switched in advance is reached due to the error of the rough search. To provide the track jump control device.

[0010]

In order to solve the above-mentioned problems, a track-jump control device according to the present invention provides (1)
Rotation drive means (for example, a spindle motor drive unit) for rotating the disk-shaped recording medium at a constant angular velocity, and (2) setting a plurality of data areas on the disk-shaped recording medium based on the radial position thereof, and for each data area. A recording / reproducing frequency setting means (for example, a recording / reproducing frequency generating section) for setting a recording / reproducing frequency adapted to, and (3) a recording / reproducing head means (for example, an optical head) for recording / reproducing data for each data area, (4) Head moving means (for example, a linear motor and a track jump drive circuit) for moving the recording / reproducing head means in the radial direction of the disk-shaped recording medium,
(5) For each rotation of the disc-shaped recording medium, at the first timing determined with respect to the rotation period of the disc-shaped recording medium,
A track jump control device comprising a first timing generating means (for example, a jump timing generating circuit) for generating a first timing signal for causing the recording / reproducing head means to jump to the inner peripheral side of one track, (6) The first timing Second timing generation means (for example, a jump timing generation circuit) for generating a second timing signal for causing the recording / reproducing head means to jump to the inner circumference side of one track at a second timing different from (7) A jump timing switching unit (for example, a controller) for switching the first timing signal to the second timing signal when the recording / reproducing frequency is switched is provided.

[0011]

With the above structure, the recording / reproducing head unit sets the recording / reproducing frequency set by the recording / reproducing frequency setting unit due to an error in the coarse search accuracy when the head moving unit moves the recording / reproducing head unit in the radial direction. Even if a track that belongs to a data area that does not correspond to 1 is reached, the recording / reproducing head means jumps to the inner circumference side of one track at a second timing different from the first timing.
Rather than jumping to the inner circumference of one track at the timing
The probability of detecting the target track increases.

This is because the first timing signal for holding the recording / reproducing head means on the same track is generated based on the detection of the last part of one track.

That is, according to the first timing signal,
Since the recording / reproducing head means can be made to jump to the inner peripheral side only at the final portion of the erroneously arrived track, the recording / reproducing head means is held on the erroneously arrived track.

On the other hand, when the erroneously arrived track is located adjacent to the outer circumference of the target track by one track, the second timing signal indicates that recording / reproduction is performed in the middle of the erroneously arrived track. The head means can be made to jump in the middle of the target track. Alternatively, when the erroneously arrived track is located adjacent to the inner circumference side of the target track by one track, the second timing signal causes the erroneously arrived track to pass over the last part of the erroneously arrived track and reach the middle of the target track. The recording / reproducing head means can be made to jump to the inner peripheral side.

As a result, when the recording / reproducing head means is moved to the track located at the innermost or outermost part of the data area where the recording / reproducing frequency is set in advance, the recording / reproducing frequency is affected by an error of one track. Even if the recording / reproducing head unit reaches a data area that does not correspond, the probability of detecting the target track can be increased.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe one embodiment of the present invention with reference to FIGS.

As shown in FIG. 3, the disk formatted for M-CAV control is divided into a plurality of data areas (hereinafter referred to as zones) according to the radial position.
In FIG. 3, in order to simplify the drawing, only zones 1 to 3 are shown, and spiral tracks provided in each zone 1 to 3 are also omitted. The recording / reproducing frequency is set to be constant in each zone, and is set to be higher in the zones located on the outer peripheral side.

Each track has, for example, numbers 4 to 6 in FIG.
As shown in, it is further divided into a plurality of areas. 1
Each area is called a sector, and one unit of data is recorded therein. One turn of a spiral track
Assuming that the track is a track, an ID portion is provided at the beginning of each sector in which address information indicating which track and which sector the sector belongs to is recorded.

FIG. 2 is a block diagram of a track jump control device embodying the present invention. Disk 17
The spindle motor drive unit 7 rotates at a constant angular velocity. The optical head 8 records data on the disk 17 and reads a reproduction signal. The linear motor drive circuit 10 sends a drive current for moving the optical head 8 in the radial direction of the disk 17 to the linear motor 9.

The signal processing section 11 performs processing such as waveform equalization and waveform shaping on the reproduction signal read by the optical head 8. A recording / reproducing frequency generating unit (hereinafter, referred to as a frequency generating unit) 12 generates a synchronizing signal at the time of recording / reproducing by switching in a plurality of stages according to a zone in which recording / reproducing is performed. The ID decoder unit 13 obtains address information such as a track number and a sector number from the reproduction signal processed by the signal processing unit 11.

Further, the track jump drive circuit 14 is
The optical head 8 is moved to the inner circumference side of one track, and the optical head 8 is made to stand by on the same track that can be arbitrarily selected (hereinafter, the jump operation in which the optical head 8 is made to stand by on the same track is called a hold jump. ). The jump timing generation circuit 15 gives the track jump drive circuit 14 the start timing of the track jump.
The start timing of the optical head 8 is as described later.
Switched when moving between zones.

The control controller 16 is a control unit for performing zone management and comprehensive control of the system including recording and reproducing operations based on the address information received from the ID decoder unit 13, and controls the spindle motor drive unit 7. It gives an instruction of the angular velocity error amount, an instruction of the movement amount to the linear motor drive circuit 10, an instruction to switch the synchronization signal to the frequency generator 12, an instruction to switch the start timing to the jump timing generator circuit 15, and the like.

Next, FIG. 4 shows the hold jump timing used in the present invention. The first timing signal TS ₁ shown in FIG. 4A is generated by the jump timing generation circuit 15 based on the detection of the ID part of the last sector of each track. While the recording / reproducing operation is on standby, a hold jump is performed in synchronization with the falling edge of the first timing signal TS ₁ . On the other hand, the second timing signal TS ₂ shown in FIG. 4B has the above first signal so that the hold jump is performed in the sectors other than the last sector.
It is generated by delaying the timing signal TS ₁ by a certain time t. As will be described later in detail, in which sector of the destination track the hold jump is performed is time t.
And the amount of movement of the optical head 8 in the disk radial direction.

Although not described in detail, the first timing signal TS ₁ and the second timing signal TS ₂ are artificially output by interpolation even when the ID part becomes unreadable.

Further, the timing switching signal TS _c shown in FIG. 4C is the first timing signal TS ₁ and the second timing signal TS _c .
The controller 16 supplies the jump timing generating circuit 15 for switching between the timing signals TS ₂ . In this embodiment, the first timing signal TS ₁ is switched to the second timing signal TS ₂ before and after the movement to the track belonging to the zone different from the zone where the optical head 8 is located, and the ID of the target track is changed. When the parts are confirmed, they are returned to the first timing signal TS ₁ .

FIG. 1 shows a specific configuration of the main part of the jump timing generation circuit 15 for carrying out this timing switching. The first timing signal TS ₁ is supplied to one input terminal of the counter circuit 21 and the LAW ACTIVE NAND circuit 23. The counter circuit 21 is supplied with a clock signal from the controller 16. The output of the counter circuit 21 is connected to one input terminal of the LAW ACTIVE NAND circuit 24.

Further, the timing switching signal TS _c output by the controller 16 is supplied to the other input terminal of the LAW ACTIVE NAND circuit 23 via the inverter 22 and also to the other input terminal of the LAW ACTIVE NAND circuit 24. Is being supplied. LAW ACTIVE NAND circuit 23
Each output of 24 is connected to each input terminal of the LAW ACTIVE NOR circuit 25. The output of the LAW ACTIVE NOR circuit 25 is supplied to the track jump drive circuit 14.

The operation of the jump timing generating circuit 15 will be briefly described. By counting a predetermined number of clock signals, the counter circuit 21 delays the first timing signal TS ₁ by a predetermined time t to generate a second timing signal TS ₂ as shown in FIG. 4B.

When the timing switching signal TS _c is at high level, the LAW ACTIVE NAND circuit 23 opens the gate, while the LAW ACTIVE NAND circuit 24 closes the gate. At this time, the LA connected to the output of the LAW ACTIVE NAND circuit 24
Since the input terminal of the W ACTIVE NOR circuit 25 becomes low level, the LAW ACTIVE NOR circuit 25 uses the first timing signal T
Output S ₁ .

On the other hand, when the timing switching signal TS _c is at low level, LAW ACTIVE
The NOR circuit 25 outputs the second timing signal TS ₂ .

FIG. 5 shows that the hold jump is performed in the last sector of the track by the first timing signal TS ₁ . The beam spot P projected from the optical head 8 onto the disk 17 rotating in the direction indicated by the arrow R
Is, for example, from n + 2 th track T _{n + 2} of the last sector S _l, performs hold jump n + 1 th track T _{n + 1} adjacent to the one track inward into the end sector S _l '. As a result, it can be seen that the ID portion (hatched in FIG. 5 for convenience) of the same track (that is, the track T _{n + 1} ) is always read. In other words, the beam spot P is the I of a sector located on the same track.
Only part D can be read.

On the other hand, as shown in FIG. 6, according to the second timing signal TS ₂ , the beam spot P is, for example, a sector S located in the middle of the track T _{n + 2} other than the last sector S _{l. From m} , the track T inside one track
_A hold jump is performed to the sector _Sm 'located in the middle of _{n + 1} . That is, two tracks T _{n +} adjacent to each other
_It can be seen that the ID part of the sector included in ₁ · T _{n + 2} is read.

Next, the method for carrying out the present invention will be specifically described. As shown in FIG.
Consider one zone 1-3. 0000H in zone 1
It is assumed that track numbers from 1 to 1FFFH correspond, zone 2 corresponds to track numbers from 2000H to 2FFFH, and zone 3 corresponds to track numbers from 3000H to 3FFFH. further,
It is assumed that the optical head 8 is located on the track included in the zone 1, the recording / reproducing frequency corresponding to the zone 1 is set, and the first timing signal TS ₁ is used.

It is assumed that the optical head 8 is moved onto a track represented by a track number 2FFFH (hereinafter simply referred to as track 2FFFH). The controller 16 calculates the difference in the number of tracks between the current track and the destination track 2FFFH, applies a voltage corresponding to the amount of movement to the linear motor drive circuit 10, and causes the linear motor 9 to move the optical head 8. Since the recording / reproducing frequency and the hold jump timing have to be switched immediately before or after the optical head 8 is moved, the controller 1
Reference numeral 6 gives a timing switching instruction for switching the recording / reproducing frequency corresponding to the zone 2 to which the destination track belongs to the frequency generation unit 12, and switching timing for instructing switching from the first timing signal TS ₁ to the second timing signal TS ₂ . The signal TS _c is supplied to the jump timing generation circuit 15.

When the controller 16 determines that the optical head 8 has reached the vicinity of the target track 2FFFH, the rough search operation by the linear motor 9 is terminated. However, it is assumed that the optical head 8 has reached the track 3000H on the outer peripheral side of one track adjacent to the target track 2FFFH due to an error in the rough search operation. Track 3000H belongs to Zone 3,
Due to the incompatibility with the recording / reproducing frequency corresponding to the zone 2 which was switched in advance, the ID portion of the sector included in the track 3000H cannot be read normally.

In particular, the first timing signal T ₂ is not changed to the second timing signal TS ₂ as in the conventional case.
When the hold jump is activated by S ₁ , the hold jump is performed in the last sector of the track 3000H, so the optical head 8 cannot read the ID part of the sector included in the track 2FFFH at all.

However, the second timing signal TS of the present invention
_{If the} hold jump can be activated in the sector located in the middle of the track 3000H by ₂ , the optical head 8 can jump to the middle sector included in the track 2FFFH and detect a part of the track 2FFFH. be able to. However, immediately after the timing given by the second timing signal TS ₂ , the optical head 8
Reaches the track 3000H, the optical head 8 cannot jump to the track 2FFFH.

This will be described in more detail with reference to FIG.

[0039] For simplicity of explanation, consider the four tracks T _R0 through T _R3 sequentially adjacent to the outer side from the inner peripheral side, and each track T _R0 through T _R3, setting different recording frequencies from each other Shall be done. Also, track T _R0
T _R1 has six sectors T _{R0 -1 to} T _R0-6 and T _{R1-1 to} T _R1.
R1-6 is provided in the track T _R2 · T _R3 are eight sectors T _R2-1 ~T _R2-8, it is assumed that T _R3-1 ~T _R3-8 is provided (for each sector For convenience, the ID section located at the beginning is
Hatched).

The first timing signal TS ₁ is sent by the optical head 8 to the last sector T _R0-6 , T _R1-6 , T _R2-8 , or T _R3-8.
Is reached, the jump timing generation circuit 15 supplies the track jump drive circuit 14 with the track timing drive circuit 14.
As a result, the optical head 8 jumps to the final sector on the inner circumference side of one track.

Regarding the second timing signal TS ₂ , 3
Consider different types of hold jump timing. That is, the second timing signal TS ₂ -J ₁ gives the hold jump timing J ₁ in the first half of the sector, the second timing signal TS ₂ -J ₂ gives the hold jump timing J ₂ in the middle portion sectors, Second timing signal T
S ₂ -J ₃ is to give a hold jump timing J ₃ in the second half of the sector. Second timing signal TS ₂
-J ₁ ~TS ₂ -J ₃ are both capable of a first timing signal TS ₁ by using the counter circuit 21 may be delayed a predetermined time.

Here, if the target track is a track T _R2
Table 1 below shows the detectability of the track T _R2 when the optical head 8 reaches the sector at a different position. [1] to [11] in Table 1 correspond to the arrival positions [1] to [11] of the optical head 8 in FIG. 7. Further, the meanings of ◯, Δ, and × respectively mean that ◯ ... the ID part of the target track can be reproduced. Δ ... Depending on the arrival position of the optical head 8, the ID part of the target track can be reproduced or not. ... The ID part of the target track cannot be played.

[0043]

[Table 1]

In Table 1, the optical head 8 tracks the track T.
When reaching the _R1, potentially ID of somewhere sector of the track T _R2 by the first timing signal TS ₁ is detected little. The only possibility is that the optical head 8 reaches the sector T _R1-6 after the first timing.

Further, the case where the track T _R2 can be detected is limited to the case where the optical head 8 reaches any sector of the track T _R2 . This is because the first timing signal TS ₁ can cause the optical head 8 to hold and jump only in the final sector of the track reached by the optical head 8. That is, the first timing signal TS ₁ holds the optical head 8 on the track that has arrived by mistake.

On the other hand, for example, according to the second timing signal TS ₂ -J ₁ , when the optical head 8 reaches any of the sectors T _{R1-3 to} T _R1-6 belonging to the track T _R1 , the track hold jump is performed on a sector-by-sector T _R2-3 belonging to T _R2. Therefore, in this case, the sector T _R2-1
To ID of T _R2-3 are detected.

If the optical head 8 reaches the sector T _R1-2 at the time when the hold jump timing given by the second timing signal TS ₂ -J ₁ is passed, similarly, the sector T _R2- The ID portion from ₁ to TR _2-3 is detected. Therefore, the evaluation for sector T _R1-2 is Δ
Becomes

[0048] When the optical head 8 has reached the Sector T _R3-6 belonging to the track T _R3, for example, a second timing signal TS ₂ -J ₃ are sector T _R2 belonging from the sector T _R3-7 the track T _R2 Jump the optical head 8 to _-7 .
Therefore, in this case, the ID portion of the sector T _R2-8 is detected.

As described above, even if the optical head 8 erroneously reaches the sector on the one track inner circumference side or one track outer circumference side of the target track, the second timing signal T
S ₂ -J ₁ ~TS ₂ -J ₃ are be selected which, first
The detectability of the target track can be significantly increased as compared with the timing signal TS ₁ .

Therefore, when the target track is located at the innermost or outermost part of the zone in which the recording / reproducing frequency is set in advance, the optical head 8 is displaced by one track from the target track, and the recording / reproducing frequency is changed. Even if the zone which does not conform is reached, a part of the sector included in the target track can be detected unless the arrival timing has passed the hold jump timing given by the second timing signal TS ₂ .

Since the track located at the innermost part of the zone, that is, the so-called start track is frequently accessed, according to the track jump control apparatus of the present invention, M
-The reliability of the access operation to the CAV control compatible disk is improved, and the recording / reproducing of the zone of the moving destination can be started quickly.

Note that, for example, if the ID portion cannot be reproduced at all after the waiting time of one rotation on the same track,
The position information can be obtained by determining that there is a high possibility that the recording cannot be performed due to the mismatch of the recording / reproducing frequencies and switching the recording / reproducing frequency.

In this embodiment, the hold jump timing is switched when accessing different zones. However, if there is no particular problem, the hold jump timing may be switched from the beginning to a sector other than the last sector. You can leave it.

Further, in this embodiment, the second timing signal TS ₂ is set to the first timing signal TS ₂ based on the detection of the ID portion of the last sector.
Although it is generated based on the timing signal TS ₁ , it may be generated based on a reference clock used for rotation control of the spindle motor.

[0055]

As described above, the track jump control device according to the present invention causes the recording / reproducing head means to operate at the second timing different from the first timing determined for the rotation period of the disk-shaped recording medium. Second timing generating means for generating a second timing signal for jumping to the inner circumference side of one track based on the first timing signal, and when the recording / reproducing frequency is switched, the first timing signal is changed to the second timing signal. And jump timing switching means for switching to.

Therefore, when the recording / reproducing head means is moved to the track located at the innermost peripheral portion of the data area for which the recording / reproducing frequency is set in advance, the inner periphery where the recording / reproducing frequency does not correspond due to an error of one track. Even if the recording / reproducing head means arrives at the side data area, the second timing signal causes the recording / reproducing head means to jump to the inner peripheral side in the middle of the target track, passing over the last part of the accidentally arrived track. be able to.

As a result, since a part of the target track can be detected and its position information can be obtained, the reliability of the access operation to the disc-shaped recording medium having a plurality of data areas having different recording / reproducing frequencies is improved. There is an effect that can be.

Further, when the recording / reproducing head means is moved to the track located at the outermost peripheral portion of the data area for which the recording / reproducing frequency is set in advance, data on the outer peripheral side where the recording / reproducing frequency does not correspond due to an error of one track. Even if the recording / reproducing head means reaches the area, the second timing signal makes it possible to cause the recording / reproducing head means to jump to the inner circumference side from the middle of the erroneously arrived track to the middle of the target track.

As a result, similarly to the above, since it is possible to detect a part of the target track and obtain its position information, it is possible to perform the access operation to the disk-shaped recording medium having a plurality of data areas having different recording / reproducing frequencies. An effect that reliability can be improved is exhibited.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part of a jump timing generation circuit in a track jump control device of the present invention.

FIG. 2 is a block diagram schematically showing a configuration of a track jump control device of the present invention.

FIG. 3 is an explanatory diagram showing a disk-shaped recording medium formatted according to the M-CAV system.

FIG. 4 is a timing chart showing a relationship between input / output signals of a jump timing generation circuit.

FIG. 5 is an explanatory diagram showing an enlarged view of a beam spot when a hold jump is performed based on a first timing signal.

FIG. 6 is an explanatory diagram showing an enlarged state of a beam spot when a hold jump is performed based on a second timing signal.

FIG. 7 is an explanatory diagram schematically showing the relationship between the arrival position of the beam spot and the position to which the hold jump timing is given.

[Explanation of symbols]

7 Spindle Motor Driving Section (Rotation Driving Means) 8 Optical Head (Recording / Reproducing Head Means) 9 Linear Motor (Head Moving Means) 10 Linear Motor Driving Circuit (Head Moving Means) 12 Recording / Reproducing Frequency Generating Section (Recording / Reproducing Frequency Setting Means) 14 track jump drive circuit (head moving means) 15 jump timing generating circuit (first timing generating means and second timing generating means) 16 control controller (jump timing switching means) 17 disk (disk-shaped recording medium)

Claims (1)

[Claims] 1. A rotary drive means for rotating a disk-shaped recording medium at a constant angular velocity, and a plurality of data areas are set on the disk-shaped recording medium based on its radial position.
The recording / reproducing frequency setting means for setting a recording / reproducing frequency suitable for each data area, the recording / reproducing head means for recording / reproducing data to / from each data area, and the recording / reproducing head means in the radial direction of the disk-shaped recording medium. A head moving means for moving the recording / reproducing head means for jumping to the inner circumference side of one track at a first timing determined with respect to the rotation period of the disk-shaped recording medium for each rotation of the disk-shaped recording medium; In a track jump control device having a first timing generating means for generating one timing signal, a second timing for causing the recording / reproducing head means to jump to the inner circumference side of one track at a second timing different from the first timing. Second timing generating means for generating a signal based on the first timing signal; When the example is performed, the track jump control apparatus characterized by and a jump timing switching means for switching the first timing signal a second timing signal.