JPH0235387B2 - KIROKUDEISUKUNOKIROKUOYOBISAISEIHOSHIKI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording/reproducing method for a recording disk, and more particularly to a recording/reproducing method for a lead-out signal on a recording disk.

In recent years, optical recording disks have become available as recording media that can record information at a high density, but in order to achieve higher density, instead of a constant rotational angular velocity type like conventional music records, it is possible to record information at an arbitrary radial position. A constant linear velocity disk has a constant linear velocity in the direction of the recording track.
Velocity Disc (hereinafter abbreviated as CLV disk)
Methods to do so are being implemented. In addition, by recording digital signals such as PCM signals on such high-density recording media, it can be used as a compact music record that has good sound quality and can be recorded for a long time, or as a high-density memory. There is a lot of research going on. Since the track pitch of such discs is very narrow, usually around 1 to 2 μm, in order to locate the desired information position on a playback device (hereinafter abbreviated as search), it is necessary to use the musical tone converted into a digital signal at the time of recording. Address data for searching is mixed and recorded between the time series of information data such as A method in which the desired search position is reached by repeatedly moving the and pick-up in the radial direction using a fast-forwarding means, that is, performing the fast-forwarding operation in an appropriate direction toward the outer circumference or inner circumference of the disk. is possible. Furthermore, it is naturally possible to perform a fast-forward operation not only for such a search but also for simply changing the radial position at which reproduction is desired.

On the other hand, in the case of a CLV disk, if the track radius is different, the disk rotation speed to obtain a predetermined linear velocity will be different. Therefore, when changing the track radius by rapid traverse as described above, it is also necessary to change the disk rotation speed accordingly.
This rotation servo is required (hereinafter referred to as spindle servo). As a method for performing spindle servo during fast-forward operation, the inventor proposed a method in which the clock frequency is extracted from the playback signal obtained from the pickup during fast-forward operation, and the disk is rotated so that this clock frequency remains constant. For details, please refer to
56-5899, 5900 and 5901.

According to these methods, it is possible to perform spindle servo during fast forwarding, but if the pick-up deviates to a non-recording area during fast forwarding,
Since the servo signal for performing spindle servo cannot be obtained, the spindle servo goes out of control.

In general, in a disk-shaped recording medium, the track radius at the start position of information is mechanically determined by the format, but the track radius at the end position of information varies depending on the amount of recorded information. Therefore, a method has been realized in which the track radius of the end position of information is known in advance, the current playback track radius is known by a mechanical detection method, and the playback position does not protrude into areas where no information is recorded. Can not. In addition, even if a lead-out signal in a predetermined format determined by the format is recorded for a predetermined width after the end of information on a disk-shaped recording medium, in order to increase the density of information, the amount of information is reduced like the lead-out signal. Signals that are not involved are often not recorded for very long. On the other hand, when attempting to search for a certain information location, depending on the relative relationship between the current location and the desired location, the disk and pick-up are moved relatively to the desired location using fast forwarding means, and the address data is read. A possible method would be to fast forward in the same direction again if the address data has not yet been sent to the desired position, and if it turns out that the address data has passed the desired position, read the address data while going back little by little in the opposite direction. If you use this search method, if the address is in the format of track number, minute, and second, and there is no absolute address, like a digital audio disc, the distance to be fast-forwarded at one time will be longer than the width of the lead-out signal. If so, the lead-out signal may not be read and the track may end up in an unrecorded area. For example, on a disk where information is recorded from the inner circumference to the outer circumference as shown in FIG. Even if the last address c is just before the destination address b, if c and b have different song numbers, you won't know that you're almost there, so the next fast-forward will be until now. Similarly, the width is greater than the width of the lead-out signal in the outer circumferential direction, and the position d where the address is stopped at next time becomes a portion without a track. If you want to avoid protruding from the track like this, it is obvious that the distance of one fast-forward must be less than the width of the lead-out signal, but if you do this, you will have to search while reading the address very frequently. Therefore, when attempting to search from the vicinity of the innermost circumference to the vicinity of the outermost circumference, the search time becomes extremely long. For example, if the innermost radius is 23mm, the outermost radius is 58mm, and the width of the readout signal is 0.5mm, reading the address at intervals of 0.5mm or less from the innermost radius to the outermost radius will result in 70. If you need to read the address more than once, and it takes 50mS to read the address once, the total time spent reading the address alone will take more than 3.5 seconds until you realize that you have passed the target position. Therefore, this is not preferable for realizing a quick search.

The above numerical value is just an example, but if the width of the lead-out signal is narrow and you try to avoid the lead-out signal from being intruded, you will not be able to fast-forward a long distance at a time as described above, which will result in a search time. This increases the number of discs, which becomes an obstacle to providing an easy-to-use disc player.

In the numerical example above, if the width of the readout signal is 3.5 mm, if you read the address at intervals of 3.5 mm or less from the innermost circumference to the outermost circumference, you will only need to read the address a little more than 10 times. Therefore, the total time spent reading the address before realizing that it has passed the target position is
Although the time is considerably shortened to just over 0.5 seconds, recording a signal that is not an information signal, such as a lead-out signal, over a large width is undesirable because it leads to a decrease in the amount of information. In particular, in the case of a disc that records from the inner circumference to the outer circumference, the lead-out signal will be recorded in an area with a larger radius than the outer circumference, and if it is a CLV disk, the lead-out signal will have a large width near the outer circumference. The presence of the signal results in a significant reduction in the maximum amount of information that can be recorded.

Another method, when there is little information to be recorded, is to record the lead-out signal in the entire remaining area where the track can be formed. A method of always keeping constant is considered, but this would result in a significant increase in disk mastering time. For example, if you want to record 5 minutes of information on a recording disc whose maximum recordable time is 60 minutes, and if all 55 minutes after this 5 minutes of information are used as a lead-out signal, the mastering time would normally be just over 5 minutes. This is inconvenient since it takes 60 minutes. In FIG. 1, 1 indicates the center of the disk, 2 indicates the innermost recording track, 3 indicates the information recording section, 4 indicates the lead-out signal recording section, and 5 indicates the non-recorded portion.

The present invention provides a recording method for a recording disk that can record as much information as possible on a recording disk whose recording track format area is limited, can expect a short search time, and does not cause an unnecessary increase in mastering time, and its reproduction. The purpose is to provide a method.

The recording method according to the present invention is a recording method for a recording disk in which the width in the radial direction of the recordable disk is set to a constant value W ₀ , and the recording method is a recording method for a recording disk in which the width in the radial direction of the recordable disk is set to a constant value W 0. Let W ₁ be a certain width that is slightly larger than the maximum fast-forwarding distance, and the width W _S of the information recording part is
If W _S ≦ W ₀ − _{W 1} , the recording width of the lead-out signal indicating the end of the information recording portion is recorded to a constant value W ₁ , and if W _S > W ₀ − W ₁ , this W ₀ −
The part W _S is the recording part of the lead-out signal, and the minimum width of this lead-out signal recording part is
The present invention is characterized in that the pick-up is set to a predetermined width _W2 that is larger than the distance that the pick-up moves from when the fast-forwarding operation stop command is issued until it stops.

In the reproduction method according to the present invention, the relationship between the widths W _S and W _L of the information recording section and the lead-out signal recording section is W ₁
This is a fast-forward playback method for recording discs that are recorded so that ≧W _L = W ₀ - _{W S} ≧ W _2. The feature is that the pick-up is approximately a predetermined width W from the end edge of the lead-out signal recording area. This feature is characterized in that the fast forward movement is stopped when it is detected that the position has reached the inner position by ₂ .

The present invention will be explained below using the drawings.

FIGS. 2A to 2E are partially enlarged views of the periphery of the recording disk for explaining the embodiments of the present invention, and for the sake of simplicity, all portions that should be circular arcs are shown as straight lines. Parts equivalent to those in FIG. 1 are designated by the same reference numerals. Generally, the recordable radial width of a recording disk is determined, and if this is W ₀ (constant), then the radial width of the information recording area to be recorded (hereinafter simply referred to as width) W _S The relationship between the width W _L of the lead-out signal recording portion and the width W L of the lead-out signal recording portion must always be as follows: W _S +W _L ≦W ₀ (1). Therefore, when there is little information to be recorded, the width W _L of the lead-out signal can be made sufficiently large, but as mentioned above, the mastering process becomes large and this is not a good idea. Therefore, in such a case, the recording width _WL of the lead-out signal is set to a constant value _W1 for recording, an example of which is shown in FIGS. 2A and 2B. In other words, in A, the relationship W _S < W ₀ − W ₁ (2) is shown, and in B, the relationship W _S = W ₀ − W ₁ (3) is shown. It is shown. Note that line 6 indicates the end edge of the area where recording tracks can be formed.

Here, the constant width _W1 as the lead-out signal recording width is set to a value slightly larger than the maximum fast-forward distance at one time during fast-forward operation in the disk radial direction between the disk and the pickup of the playback device. Therefore, when searching toward the outer periphery with the playback device, the fast-forward operation is stopped every width W ₁ ′ that is slightly smaller than the width W ₁ and the address data is determined so that the current address skips the target address. It is determined whether or not it has been exceeded, and if it has not been exceeded, fast-forward movement is performed again in the same direction by the width W ₁ '. By doing this, in any case where the target address is outside the address f that was last read, the next stop position will always be in the lead-out signal recording section 4.
Therefore, since the lead-out signal is read, it is determined that the target address is between f and g. Therefore, the pickup will not deviate to the unrecorded area 5.

Next, as the amount of information to be recorded increases and the relationship becomes W _S > W ₀ − W ₁ (4), it is necessary to always satisfy equation (1), so the readout signal Width of recording section 4 W _L
becomes smaller accordingly, and W ₁ > W _L = W ₀ − W _S (5). In such a case, the lead-out signal is recorded with a width of W ₀ - W _S , but the minimum value is within the specified width.
It is considered W ₂ . This _W2 is set to a value that is slightly larger than the distance that the pickup moves from when the fast forward stop command is issued until it stops. That is, the relationship is set as follows: W ₁ >W _L =W ₀ −W _S ≧W ₂ (6).

Then, in the case of the relationship shown in equation (4) or equation (6) above, the playback device detects that the pick-up has reached a position inside the lead-out end edge 6 by approximately a predetermined width W ₂ and stops the fast-forward movement. A structure is adopted that applies a brake to the movement of the pick-up.

Figures 2C and 2D show examples of each field in the relationship shown in equation (6) above, where W _L = W ₀ − W _S > W ₂ (7) W _L = W This is the case when ₀ −W _S =W ₂ ......(8). A line 7 indicates a portion corresponding to a position inside the terminal edge 6 of the lead-out signal recording portion 4 by a width W ₂ .

In both figures C and D, if the target address is located further outside than the last read address f, then normally the next fast-forward movement would be by width W ₁ ' and it would deviate from the recorded area. However, in this example, when the pick-up passes the position 7 that is a width W ₂ inside from the terminal edge 6 of the lead-out signal recording section 4, this is detected, and the rapid forward movement is stopped instantly and the brake is applied to the pick-up movement. It is done so that it is applied. Here, since the width W ₂ is selected to be slightly larger than the travel distance of the pick-up until it is stopped by the brake, the pick-up will not deviate from the unrecorded area 5.

For example, when the rapid traverse speed is 30 mm/sec and the deceleration by the brake is 1 G (such numerical examples are fully achievable), the distance the pickup moves is about 46 μm. Therefore, at most 100 μm is sufficient for W ₂ , but in reality,
Since there is an eccentricity between the center of the recording track and the center of the recording disk, which is usually 50 to 100 μm, W ₂
The width needs to be at least 100μm, which is 0.3~0.5mm.
The width is appropriate.

In addition, as another example, as shown in Fig. 2E, W ₂
It may also be possible to detect that the pickup passes through a position 7' whose width is greater than the width of the pickup. In this case, the read-out signal 4 can be read without fail by setting the position 7' to the inner side of the position 7 by about 1 mm, and by setting the distance of one quick feed to about 0.3 mm outside the position 7'. Furthermore, the detection accuracy at position 7' may be low.

As mentioned above, the distance of one fast feed is usually the width
Since the width W _{1 ′} can be smaller than W ₁ , for example, W ₁
If it is set to 3.7 to 4 mm, W ₁ ' will be about 3.5 mm. Therefore, even if the width W _S of the information recording portion 3 is at most 35 mm, the address will be within at least 3.5 mm of the target address by reading the address a maximum of 10 times.
Even when method E is adopted, if the target address is outside position 7', it can be seen that by reading the address at most 15 times, the address can be within at least 0.3 mm of the target address.

Once you know that it is within 3.5mm of the target address, then by reading the address at intervals of 0.5mm, for example, you can find that it is within at least 0.5mm of the target address in about 7 times. Recognize. Therefore, the number of addresses read until this stage is reached is about 17 times at most. If the readout signal is always 0.5mm wide, then 35mm
It takes about 70 readings to read the recording width at 0.5 mm intervals and find out that the target address is within 0.5 mm of the target address, which demonstrates the effectiveness of the lead-out signal recording method according to the present invention. can be understood.

Also, the maximum amount of information that can be recorded is
It is clear that there is no difference at all between setting W ₂ to 0.5 mm and simply setting the lead-out signal recording width to 0.5 mm, and it is also easier to master than when setting the lead-out signal to everything outside the information track. It is also clear that it takes less time.

FIG. 3 is a block diagram illustrating the reproduction method of the present invention, in which a clock extraction circuit 21 selectively extracts only clock components representing phase information from the reproduction signal from the pickup 20. Since this circuit 21 has a PLL (phase locked loop) circuit configuration, it is possible to generate a signal synchronized with the reproduced clock signal even during fast forwarding by the so-called flyhole effect of the PLL circuit. The phase of this reproduced clock signal is compared with the reference signal Vr in a phase error generating circuit 22 to generate an error signal. This error signal controls the rotation of a spindle motor (not shown) via the spindle motor drive circuit 23, and disk rotation is controlled to maintain a substantially constant linear velocity even during fast forwarding.

A control circuit 25 is provided for fast-forward control, and in response to a fast-forward command signal, the pickup is controlled so that the moving distance in the disk radial direction is the maximum W ₁ ' each time. Each time, the address information is read and compared with the target address, and control is performed according to the difference. On the other hand, a position detector 2 for determining the position of the pickup 20 in the disk radial direction
4 is provided, and 7 or 7' shown in FIG.
The device is configured to detect the moment the pick-up crosses the position of the pickup and generate a detection signal.
For example, a potentiometer or the like may be used. This detection signal causes the fast forward control circuit 25 to respond and apply a brake to the pickup.

As described above, according to the present invention, it is possible to effectively maintain the amount of recorded information on a disc, reduce mastering time, and perform a search in a short time.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the movement of the pickup during fast forwarding at the end of the recorded portion of the recording disk, FIGS. 2A to 2E are diagrams illustrating each embodiment of the recording method of the present invention, and FIG. FIG. 2 is a schematic block diagram illustrating a reproduction method. Explanation of symbols of main parts, 3...Information recording part,
4...Leadout signal recording portion, 5...No recording portion, 20...Pickup, 24...Pickup position detector, 25...Fast forward control circuit.

Claims (1)

[Scope of Claims] 1. A recording method for a recording disk in which the width in the radial direction of the recordable disk is set to a constant value W ₀ , wherein 1 during a fast-forward operation in the radial direction of the recording disk and a pick-up during playback. Let W ₁ be the width that is slightly larger than the maximum fast-forwarding distance of the time, and if the width W _S of the information recording section is W _S ≦ W ₀ − W ₁ , then the recording width of the lead-out signal indicating the end of the information recording section is
Record it so that W ₁ , and if W _S > W ₀ − W ₁ , then
The part with a width of W ₀ - W _S is set as the lead-out signal recording section, and the minimum width of this lead-out signal recording section is set to a predetermined width that is larger than the distance that the pickup moves from when the fast forward operation stop command is issued until it stops. A recording method characterized by being set to W ₂ . 2 The width of the recordable disk in the radial direction is a constant value W ₀ , and the width is W ₁ which is slightly larger than the maximum fast-forward distance in one fast-forward operation in the disk radial direction between the recording disk and the pickup during playback. In addition, when the predetermined width W ₂ is greater than the distance that the pickup moves from when the fast forward operation stop command is issued until it stops, the width W _S of the information recording section and the lead-out signal indicating the end of this information recording section are determined. The relationship with recording width W _L is W ₁ ≧ W _L = W ₀
- In a fast-forward playback method for a recording disc recorded so that _{W S} ≧ W ₂ , the pickup reaches a position approximately the predetermined width W ₂ inside from the end edge of the lead-out signal recording portion. A method characterized in that the rapid forward movement is stopped upon detection.