JPS63112864A - Recording and reproducing disk device - Google Patents

Abstract

PURPOSE:To control a revolving speed of a disk with high accuracy by holding a revolving speed of a recording and reproducing disk at the time of reproducing immediately after switching of a control system when a reproducing operation is shifted to a recording operation, and thereafter, shifting said revolving speed to a revolving speed determined by a position of a recording and reproducing head. CONSTITUTION:When a reproducing operation is shifted to recording operation, a revolving speed control system is switched from a first control system to a second control system. Also, a revolving speed of a recording and reproducing disk, stored in a storage means is set as a revolving speed condition which is supplied by the second control system to a revolving speed control means, and thereafter, the revolving speed of the recording and reproducing disk is shifted gradually to a revolving speed determined in accordance with a position of a recording and reproducing head. In such a way, it is prevented that the revolving speed goes to unstable by switching of the control system when the reproducing operation is shifted to the recording operation, and the revolving speed of the recording and reproducing disk can be controlled with high accuracy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a recording/reproducing disk device, in particular, to drive the recording/reproducing disk in such a way that the relative linear velocity with respect to a recording/reproducing head for recording/reproducing information is constant. The present invention relates to a recording and reproducing disc device that performs controlled recording of information on an unformatted recording and reproducing disc and reproducing information from the recording and reproducing disc.

[Prior Art] Optical disks are known as information recording media that are capable of recording at a higher density than magnetic disks and have excellent stability of recorded information against disturbances such as noise. Optical discs currently in practical use are playback-only and are used to record audio signals, image signals, and the like.

In response, research on optical discs that can be both recorded and played back by user devices is also progressing. As optical discs that can be recorded in a user device, there are known write-once (DRAW) type optical discs and erasable type optical discs that can erase recorded information. In this type of apparatus, an optical disk is rotated at high speed by a spindle motor, an optical head capable of recording and reproducing is positioned at a predetermined position on the radius of the optical disk, and recording and reproducing are performed on the disk.

CA is the control method for the spindle motor during recording and reproduction.
Two types are known: the V (constant angular velocity) method and the CLV (constant linear velocity) method. The CAV system is a system in which information is recorded and reproduced by rotating the spindle motor of the disk at a constant rotation speed, and the CLV system is a system in which recording and reproduction is performed by always keeping the relative speed between the optical head and the optical disk constant. Comparing the two methods, the CAV method has a simple control system as it only needs to drive the spindle motor at a constant rotation speed, whereas the CLV method has a linear velocity that varies depending on the distance between the optical head and the center of rotation of the optical disk. Since it is necessary to change the rotational speed of the spindle motor so as to keep the value constant, the CLV method has a problem in that the control system is considerably more complicated than the CAV method. On the other hand, from the perspective of recording density, the CAV method is better than the CAV method for the same optical disc.
The LV method has a fixed minimum recordable bit length, so
It has the advantage that the amount of information that can be recorded per disc is large.

Currently, the optical disc device using the CLV method is the CD
(compact disc) player system. CD
As for the system, only a reproduction-only device is currently in practical use. This type of device reads audio information from tracks recorded in a spiral on an optical disc and reproduces it through a speaker or the like. In the CD system, all audio information is converted into digital data (16 bits/sample value), and this 16 bit unit data is divided into 8 bits each and recorded by EFM modulation. In EFM modulation, 8 bits of data are converted to 14 bits of data, thereby limiting the reproduction frequency band to a certain limit and making it possible to stably extract a clock during information reproduction.

Rotation control of an optical disc in a CD system is performed by the following method. In a CD, a frame synchronization signal is recorded in advance, and rotation is controlled by detecting this frame synchronization signal during playback and controlling the spindle motor so that the detected pulse and the reference clock have the same phase and frequency. ing. With this method, stable CLV servo control can be performed in the CD system. However, the above method cannot be used in an apparatus that performs additional writing or erasing on an optical disc that has no preformatting such as header information or sector separation signals. This is because no signals are recorded on the optical disc in advance. Therefore, in order to perform CLV control, a means for detecting the distance between the optical head and the center of rotation of the optical disk and a means for detecting the rotational speed of the spindle motor are provided. The difference between the determined required disk rotation speed and the actually detected disk rotation speed at that time is used as an error signal,
A method is used to control the spindle motor based on this error signal.

FIG. 3 shows the structure of a conventional apparatus for recording and reproducing on write-once and erasable optical discs, which controls a spindle motor using the above-described method. Here, a structure is shown in which the optical disc is used as a so-called general-purpose filing device for recordable CDs (compact discs), document files, electronic albums, and the like.

In the figure, reference numeral 101 denotes an optical disc which is a recording medium, and this optical disc is rotationally driven by a spindle motor 102. The rotation speed of the spindle motor 102 is controlled by various types of FG (frequency generator) 10 such as optical or magnetic type.
Detected by 3. In addition, the spindle motor 102
The rotation speed is controlled by a motor drive circuit 111.

An optical head 104 is movably supported on the radius of the optical disk 101, and by moving the optical head 104 to a position on a certain radius, recording and reproduction can be performed on the optical disk 10. The position of the optical head 104 is detected by a position detector 106. Position detector 10
6 is connected to the optical head 104 by a detection arm 105, and detects the position of the optical head 104 using an optical linear encoder or the like.

A recording signal m is input to the optical head 104 from a terminal a. On the other hand, the reproduced signal reproduced by the optical head 4 is outputted from the terminal.

The operation during playback is performed as follows. During reproduction, the switch S1, which changes the servo system during recording and reproduction operations, is switched to the R side in the figure. Thereby, the motor drive circuit 111 is controlled via the synchronous separation circuit 114, the phase comparison circuit 113, and the amplifier 112 based on the reproduction signal. That is, the reproduced high-frequency reproduction signal n is input to the synchronization separation circuit 114, which detects a synchronization pattern inserted at regular intervals in the reproduction signal n, and outputs a detection pulse C. This detection pulse C is phase-compared with a reference clock d input from terminal 0 in a phase comparator circuit 113, and a control signal f is output according to the phase difference between the two. The spindle motor 102 receives this phase difference signal f via the motor drive circuit 111.
controlled based on As a result, the spindle motor 10
2 is controlled so that the phase and period of the reference clock d and the detection pulse C output from the synchronization separation circuit 114 are aligned.

When recording information, the switch s1 is set to W in the figure.
can be switched to the side. Thereby, the spindle motor is controlled not by the reproduction signal but by the position of the optical head 104 detected by the position detector 106. In this case, the actual rotational speed of the spindle motor 102 is detected by the FG 103, and this rotational speed signal j is input to the phase comparison circuit 109 and the edge detector 115. On the other hand, the optical head 10
The position signal g of No. 4 is generated by the phase detector 106 and input to the frequency division ratio calculation circuit 107, which forms a frequency division ratio signal corresponding to the position of the optical head in the disk radial direction. The predetermined reference clock fO is frequency-divided by the frequency divider 108.

As a result, a clock i is formed, and this clock i is input to the phase comparison circuit 109, where the phase comparison with the output signal of the FG 103 is performed.

The frequency division ratio calculation circuit 107 described above performs the following operations. For example, as shown in FIG. 6, when the distance between the objective lens of the optical head 104 and the center of rotation of the optical disk is r (m), and the constant value of the linear velocity is v□ (m/S),
The rotation speed P (rotation speed/S) of the optical disc is determined as follows.

Also, during one rotation of spindle motor 02, FG103
If a clock with a duty ratio of 50% inputted from the FG 103 is output for M periods, the clock frequency f g (Hz) generated from the FG 103 is determined by the following equation.

Therefore, there is the following relationship between r and fg.

The frequency division ratio calculation circuit 107 in FIG. 10 calculates how many times the reference clock fO should be divided in order to create fg that satisfies the relationship in equation (3) above from the positional information g of the optical head. Ru.

Edge detector 115 is controlled as follows.

The edge detector 115 detects the rising or falling edge of the output pulse of the FG 103, and inputs this edge detection signal to the frequency divider 8108 via the switch S2. The switch S2, as indicated by symbols R and W, is switched in synchronization with the switch S1. Therefore, during recording, the edge detection signal S is input to the frequency divider 108 as the reset signal t. During recording, the switch S2 is opened and input of a reset signal to the frequency divider is prohibited.

Frequency divider 108 is constructed as shown in FIG. That is, the frequency divider 108 is configured by a comparator 502 that compares the output of a latch circuit 503 that latches a frequency division ratio signal determined by a frequency division ratio calculation circuit 107 with a counter 501 . Output signal i is output from comparator 502. A reference clock fO is input to the counter 501 and latch 503. The clear terminal of the counter 501 is connected to the switch S3.
is connected. This switch S3 is indicated by the same symbols R and W as above, and the switches SL and S2 are
can be switched in sync with Thereby, the reset signal t inputted from the edge detection circuit 115 is inputted as a clear signal to the counter 501 during reproduction. During recording, by switching the switch S3 to the W side,
The counter 501 is reset by the output of the comparator 502. The comparator 502 is a counter 5 of the reference clock fo.
The count value A based on 01 is compared with the value B obtained by latching the frequency division ratio with the clock fO, and when A≧(B-1), the output i is set to high level. During recording, the counter is reset by this output signal and counts up again from 0. Switch S3 is set immediately before recording starts, that is, F during playback.
This is to keep the phase of the output signal of G103 and the phase of the divided output i of the frequency divider 108 aligned to some extent, thereby increasing the stability of CLV control when switching from playback operation to recording operation. can.

FIG. 5 shows changes in the signal j output from the FG 103, the reset signal t output from the switch S2, and the frequency-divided output signal i from the frequency divider 108 in the above configuration.

Frequency-divided signal i immediately after switching from playback operation to recording operation
starts frequency division based on timing A in FIG.

[Problems to be Solved by the Invention] By the way, when considering the above device as a general-purpose filing device for recordable CDs, document files, and electronic albums, it is inevitable to record additional information, and moreover, to record additional information in a specified location. is definitely necessary. In such an additional recording operation, the optical disk drive is first placed in playback mode, searches for a designated recording start location, and immediately switches to recording mode and starts recording operation immediately after the designated location is detected. functionality is required. Furthermore, considering the compatibility of recording on optical discs, it is necessary to ensure compatibility that an optical disc recorded by one disc drive can be played back by another drive or additional recording can be performed.

However, as mentioned above, the spindle motor similar to the optical disk is controlled by two different control systems for playback and recording, and the position detection device 1 of the optical head 104 is controlled by two different control systems.
Considering the fact that the detection accuracy of 06 varies from drive to drive, if you try to record additional information on an optical disc on which information has been recorded by one optical disc drive and another drive, the spindle rotational speed in the playback state will change. If an error occurs between V and the rotational speed of the spindle motor 102 determined from the optical head position immediately after switching from playback to recording, and this error becomes large to some extent, the recording state will change as shown in FIG. In the period of Δt immediately after switching to (timing B), CLV servo control becomes extremely unstable. Therefore, since information recorded in such a state cannot be reproduced, conventionally information is not recorded during this period of Δt.

Therefore, in an optical disk drive that performs recording and playback, C.
When attempting to use LV servo, the recording area of the optical disc is always wasted at the recording start position, which prevents high-density recording. Furthermore, although it is slight, the processing time required for recording and reproducing information is increased. moreover,
In the above section of Δt that cannot be recorded, power is wasted.

[Means for Solving the Problems] In order to solve the following problems, in the present invention, the driving rotation speed of the recording medium disk is controlled so that the relative linear velocity with the recording/reproducing head is constant. In a recording/reproducing disk device for recording information on an unformatted portion of a recording/reproducing disk following an already recorded area, the recording/reproducing disk comprises means for rotationally driving the recording/reproducing disk, and means for controlling the rotational speed of the rotational driving means; a first rotational speed control system that extracts a synchronization pattern from a reproduction signal from a recording/reproduction head when reproducing information from a recording/reproduction disk and applies a rotational speed condition to the rotational speed control means according to the synchronization pattern; and a recording/reproduction disk. a second rotational speed control system that detects the position of the recording/reproducing head on the radius of the recording/reproducing disk when information is recorded on the disk, and adjusts the rotational speed condition to the rotational speed control means accordingly; means for storing the final recording/reproducing disk rotation speed in the playback operation when moving from the playback operation to the recording operation, and switching the rotation speed control system from the first control system to the second control system when moving from the playback operation to the recording operation. At the same time, the recording/reproducing disk rotational speed stored in the storage means is used as a rotational speed condition given by the second control system to the rotational speed control means, and thereafter the recording/reproducing disk rotational speed is determined according to the position of the recording/reproducing head. We adopted a configuration that gradually shifts the rotation speed.

[Function] According to the above configuration, the rotational speed of the recording/reproducing disk at the time of reproduction is maintained immediately after switching the control system when transitioning from the reproducing operation to the recording operation, and thereafter the rotational speed is determined by the position of the recording/reproducing head. Since the number of rotations is shifted, the number of revolutions of the recording/reproducing disk can be controlled with high precision.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

FIG. 1 shows the structure of a control system of an optical disk device employing the present invention. The structure shown in FIG. 1 is similar to the structure shown in FIG. 3, and the same members as in the conventional example are given the same reference numerals. The parts in FIG. 1 that differ from FIG. 3 are the circuits in the blocks indicated by broken lines. This circuit is for controlling the rotation speed of the spindle motor 102 during a write operation on the optical disk 101. The blocks within the broken line above will be explained below.

The frequency divider 108 in the block indicated by the broken line in FIG. 1 is for feeding back a control signal to the phase comparator circuit 109, similar to the one in FIG. Frequency division ratio data h given to frequency divider 108 is formed by processing the outputs of frequency division ratio calculation circuit 107 and edge detection circuit 115 using the following logic circuit.

The frequency division ratio calculation circuit 107 outputs the frequency division ratio signal i using the same method as in the prior art example. This frequency division ratio signal i is input to the subtracter 121 together with the frequency division ratio signal actually applied to the frequency divider 108 . The subtracter subtracts the frequency division ratio data i output from the frequency division ratio calculation circuit 107 from the frequency division ratio signal actually applied, and outputs a difference signal j to the determination circuit 120.

The determination circuit 120 determines whether the above-mentioned difference signal j (=h-1) is positive or negative. When the frequency division ratio data h is larger than i, the determination circuit 120 sets the output signal k to a low level and the output signal l to a high level. Conversely, when the frequency division ratio data i is larger than h, the output is inverted, the output signal k becomes high level, and the output signal l becomes high level. When the frequency division ratio data h and i are equal, the output signal l becomes low level. be leveled. If the frequency division ratio data h and i are equal, the output signal of the determination circuit 120 may be undefined.

The determination circuit 120 can be composed of a flip-flop or the like that operates in synchronization with the clock f1.

The output signal of the determination circuit 120 controls tlP/DOWN of the up/down counter 119. The up/down counter 119 counts down when the output signal of the determination circuit 120 is at a low level, and counts up when the output signal is at a high level.

On the other hand, the output signal I of the determination circuit 120 is the 3-terminal input AN
It is input to D gate 117. The other input terminal of the AND game) 117 is connected to the clock f1 and the inverter 13.
The output signal of the switch S2 inverted at 0 is input. The switch S2 is connected to output a low level when writing and a high level when reading.

The output of the AND gate 117 is the up/down counter 11
It is given to the up/down counter 119 as a clock for incrementing 9.

On the other hand, FG1 attached to the spindle motor 102
Edge detection circuit 11 for detecting edges of the output signal of 03
The output signal r of No. 5 is input to the NAND gate 116. The other input of the NAND gate 116 receives the high level or low level signal output from the switch S2. The output signal S of NAND gate 116 is connected to reset counter 118 and
At the same time, the inverted signal S' from the inverter 131 is sent to the frequency divider 1.
It is given as a reset signal of 08.

Count data U of the counter 118 is input as preset data of the up/down counter 119. The output data of the up/down counter 119 is sent to the frequency divider 10.
8 as frequency division ratio data h.

Next, the operation of the above configuration will be explained. The above circuit is intended to eliminate CLV servo instability when switching the device from playback to write operation. Therefore, in the above circuit, the period of the output signal of the FG 103 immediately before switching from playback to recording operation is counted using the reference clock fO, and this count value is used as the frequency division ratio of the frequency divider 108. Detector 1
The optical head 104 is operated to approach a value determined according to the position of the optical head 104 on the optical disk 101 detected in step 06.

First, the operation during playback will be explained. Switch Sl, S2
is switched to the R side in FIG. 1 during reproduction. As a result, the synchronization pattern included in the reproduced signal is transmitted to the synchronization separation circuit 114, the phase comparison circuit 113, and the amplifier 11.
2, and the spindle motor 10 via switch S1.
The rotation speed of the spindle motor 102 is controlled by the same method as the conventional method.

At this time, the rotational speed detection signal output from the FG 103 is input to an edge detection circuit 115, and either the rising or falling edge of the signal is detected. The detection pulse r of the edge detection circuit 115 is input to the NAND gate 116 which is output from the switch S2 and is opened to a high level, so the output signal S of the NAND gate 116 is a signal obtained by inverting the output signal r of the edge detection circuit 115. becomes. Therefore, the counter 118 is reset every time edge detection is performed, and since the counter 118 performs a count-up operation during that time, the output signal U of the counter 118 corresponds to the period of the edge detection pulse. This periodic data U is input as preset data to the up/down counter 119 every time edge detection is performed.

As described above, during the reproducing operation, the cycle data of the edge detection signal continues to be set in the up/down counter 119 for each edge of the rotational speed signal outputted from the FG 103. As long as the playback operation continues, the up/down counter 11
Preset data 9 can always be rewritten with new values. Further, during the reproducing operation, the frequency divider 108 is reset by the edge detection signal, and is ready to output a frequency-divided output that is in phase with the rotational speed signal at any time.

Next, when moving from the playback state to the recording operation as described above,
The switches Sl and S2 are switched to the W side in the figure. As a result, the spindle motor 102 is controlled according to the phase data output from the frequency divider 108. Also, since switch S2 outputs a low level, NAND
The output of gate 116 is fixed at high level. Therefore, in the state immediately after switching, the up/down counter 119 holds a value corresponding to the edge period of the rotational speed signal of the FG 103 immediately before that.

This value is directly input to the frequency divider 108 as the frequency division ratio data of the frequency divider 108, and the frequency divider 108 controls the motor drive circuit 111 via the phase comparator circuit 109 and the amplifier 110 based on this data. Therefore, immediately after switching from the reproducing operation to the recording operation, the rotation speed of the spindle motor 102 is maintained at the value immediately before the switching. Therefore, as shown in FIG. 2, during the switching period A-B from reproduction to recording, the spindle motor 102 is controlled to the same rotation speed, and the rotation speed becomes unstable as in the conventional example shown in FIG. It never becomes.

Next, as the recording operation progresses, the optical disc 101
The rotation speed is gradually returned to a value determined depending on the position of the optical head 104. The position detector 106 detects the position of the optical head 104 as in the conventional example, and the frequency division ratio calculation circuit 107 calculates the frequency division ratio in accordance with the detected position signal as in the conventional example. ing. The frequency division ratio data i output from the frequency division ratio calculation circuit 107 and the frequency division data h actually received by the frequency divider 108 are processed by the subtracter 121, and the up/down counter is set according to the determination result. U.P.
/ DOWN is controlled. The AND gate 117 is opened by the inverted signal from the inverter 130 at a low level output from the switch S2, and if the output signal l of the determination circuit 120 is at a high level, the clock f1 is input to the up-down counter 119 as a small advance clock. be done. The clock f1 is set to a much lower frequency than the FG1030 rotation speed signal.

Since the determination circuit 120 processes 1 in the output signal as described above, if the frequency division data h is larger than 1, the frequency divider 1
The up-counter 119 gradually counts down the frequency division ratio data h given to 08 at the cycle of the clock f1, and conversely, if the actual frequency division ratio is smaller than i, it gradually counts up. That will happen.

Therefore, the frequency divider 108 outputs the spindle motor 10
The signal corresponding to the target number of revolutions 2 is gradually brought closer to the value corresponding to the position of the optical head 104 detected by the position detector 106 from the value corresponding to the number of revolutions immediately before switching from reproduction to recording. . That is, as shown in FIG. 2, the rotation speed of the spindle motor 102 is gradually switched from V immediately before the end of reproduction to V' determined by the position of the optical head 104. As is clear from a comparison with FIG. 4, according to this embodiment, the rotational speed of the spindle motor 102, that is, the optical disk 101, does not become unstable when the control system is switched, and the transition from the reproduction state to the recording state is smooth. Therefore, there is no need to refrain from the recording operation during the period when the 5 rotation speed control is unstable as shown in FIG. 4, and there is no wastage of processing time or the recording surface of the optical disc.

In the above configuration, CLV control during playback is performed using a synchronization pattern recorded in advance in the playback signal, but when CLV control is performed so that the clock itself of the playback signal is synchronized with a predetermined synchronization signal. but,
The above techniques can be applied. However, in this case, it is necessary to change the synchronization separation circuit 114 in FIG. 1 to a clock extraction circuit.

The above-described rotational speed control technology is not limited to optical disk devices, but can also be applied to magnetic disk devices and the like.

[Effects of the Invention] As is clear from the above, according to the present invention, the driving rotation speed of the recording medium disk is controlled so that the relative linear velocity with respect to the recording/reproducing head is constant, and the speed of the already recorded data on the recording/reproducing disk is A recording/reproducing disk device that records information in an unformatted area includes a means for rotationally driving a recording/reproducing disk, a means for controlling the number of rotations of the rotational driving means, and a means for reproducing information from the recording/reproducing disk. a first rotational speed control system which extracts a synchronization pattern from a reproduction signal from a recording/reproduction head and applies a rotational speed condition to the rotational speed control means according to the synchronization pattern; and a recording/reproduction head when recording information on a recording/reproduction disk. a second rotational speed control system that detects the position on the radius of the recording/reproducing disk and applies a rotational speed condition to the rotational speed control means according to the detected position; means for storing the number of rotations of the recording/reproducing disk;
When moving from a reproduction operation to a recording operation, the rotation speed control system is switched from the first control system to the second control system, and the rotation speed of the recording/reproducing disk stored in the storage means is switched to the second control system. is the rotational speed condition given to the rotational speed control means, and since the recording/reproducing disk rotational speed is gradually shifted to the rotational speed determined according to the position of the recording/reproducing head, it is possible to change from the reproducing operation to the recording operation. It is possible to provide an excellent recording/reproducing disk device that can effectively prevent the rotational speed from becoming unstable due to switching of the control system during transition, and can control the recording/reproducing disk rotational speed with high precision.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the structure of the control system of an optical disk device adopting the present invention, FIG. 2 is a diagram explaining the optical disk rotation speed control in the device of FIG. 1, and FIG. A block diagram showing the configuration of the control system of the optical disk device, FIG. 4 is a diagram showing the drawbacks of the conventional configuration shown in FIG. 3, and FIG. 5 is a timing chart showing signal waveforms of each part of FIG. 3. , FIG. 6 is an explanatory diagram showing the positional relationship between the optical receiver and the optical disk, and FIG. 7 is a block diagram showing the structure of the frequency divider shown in FIGS. 1 to 3. 101... Optical disk 102... Spindle motor 104... Optical head 106... Position detector 107... Frequency division ratio calculation circuit 108... Frequency divider 109.113... Phase comparator 115 ...Edge detector 118...Counter

Claims (1)

[Claims] Information is recorded in an unformatted portion of the recording/reproducing disk following an already recorded area by controlling the driving rotation speed of the recording medium disk so that the relative linear velocity with respect to the recording/reproducing head is constant. In a recording/reproducing disk device, a means for rotationally driving a recording/reproducing disk, a means for controlling the number of rotations of the rotational driving means, and a means for extracting a synchronization pattern from a reproduction signal from a recording/reproducing head when reproducing information from the recording/reproducing disk. a first rotational speed control system that applies a rotational speed condition to the rotational speed control means according to a synchronization pattern of the lever; detecting a position of a recording/reproducing head on a radius of the recording/reproducing disk when information is recorded on the recording/reproducing disk; a second rotational speed control system that applies a rotational speed condition to the rotational speed control means in accordance with this, and means for storing the final recording/reproducing disk rotational speed in the reproducing operation when moving from the reproducing operation to the recording operation, When moving from a reproduction operation to a recording operation, the rotation speed control system is switched from the first control system to the second control system, and the rotation speed of the recording/reproducing disk stored in the storage means is switched to the second control system. is the rotational speed condition given to the rotational speed control means, and thereafter the recording/reproducing disk rotational speed is gradually shifted to a rotational speed determined according to the position of the recording/reproducing head.