JPH07161131A - Method and apparatus for rotation control of disc apparatus - Google Patents

Abstract

PURPOSE:To obtain a rotation control method and a rotation controller for a disc apparatus by which the disc apparatus can be simplified and a motor can be made to rotate with a normal revolution instantly when a pickup reaches a target position. CONSTITUTION:Motor revolution instructions corresponding to the positions of a pickup 3 are predetermined and stored in a table form in a clock number/ motor revolution conversion table 18 and outputted through a rotation instruction generating means 19 in accordance with a seek instruction from a host 21. The revolution of an information recording disc 1 is obtained in accordance with the position of the pickup 3 on the information recording disc 1 which is detected by a position detecting means 19 and the length of a recorded information which is measured by a data interval measuring means 11 when the revolution of the information recording disc 1 is controlled and the revolution is compared with the motor revolution instruction by a revolution error sampling means 13. The revolution of the information recording disc 1 is controlled in accordance with the comparison result.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for controlling the rotation of a disk device such as a CD player or a CD-ROM device which performs constant linear velocity control.

[0002]

2. Description of the Related Art In an optical disc device such as a compact disc player, in order to increase the recording capacity per disc, motor control (CLV control-Constant Linear) is performed so that the linear velocity of the disc becomes constant.
Velocity control) is performed. If the linear velocity is constant, the data recording density is the same regardless of the diameter of the disc, and it is possible to use up to the central portion of the disc to maximize the use of the disc surface. Therefore, the storage capacity per disk can be increased.

However, when the optical pickup for recording and reproducing data is moved to an arbitrary radial position of the disc, it is necessary to change the number of revolutions of the disc, and the responsiveness of the motor for changing the number of revolutions depends on the optical pickup. This will affect the travel time, that is, the access time.
Especially, since the CD-ROM drive is used as a storage device of a computer, high speed access is required.
The issue of motor responsiveness is important.

In the CLV control, a clock of a constant cycle is extracted from the data read by the pickup and used as motor rotation phase information, which is compared with a rotation reference phase signal of a constant frequency generated by an oscillator. As a result, if the reproduction clock frequency is lower than the reference clock frequency (when the rotation speed is lower than the reference value), the motor drive command is increased to increase the rotation speed, and conversely, when it is high (when the rotation speed is higher than the reference value. ) Scanning is performed to reduce the drive command to reduce the number of revolutions, and the motor rotation is controlled so that the rotational phase information and the rotational reference phase signal have the same frequency and phase, and the linear velocity is constant. At this time, the frequency of the constant frequency clock extracted from the read data is the same regardless of the position of the pickup on the disc, and is always equal to the frequency of the rotation reference phase signal. At this time, the rotation speed of the motor becomes higher as the pick is closer to the inner circumference of the disk and lower as the pick is closer to the outer circumference.

Compact disc player, CD-RO
In the M drive, EFM modulation is performed and data is recorded on the disc as convex pits. EFM modulation is
Eight to Fourteen Modulat
Abbreviation of ion (= 8 bit, 14 bit modulation) is a method of modulating an 8-bit signal into a 14-bit signal, and the pits are converted from 3T to 11T in length to improve the reading accuracy. Here, T means the length of one clock pulse, and 3T means the length of three clock pulses.

Data is written on the disc in a physical format as shown in FIG. There is a specific bit array at every interval, separating the data into blocks. This bit array is called a sync signal, and a block of data is called a frame. 588-bit data is written in one frame. 98 frames are 1 in time
/ 75 seconds is fixed. Therefore, the time for one frame is 1/7350 seconds.

FIG. 8 is a block diagram of a conventional rotation control device for a disk device. In FIG. 8, 1 is a disk, 2 is a motor, 3 is a pickup, 4 is a pickup feed mechanism, 5 is a feed control means, 6 is a demodulation means, 7 is a motor drive means, 14 is a switching means, 15 is a PLL circuit,
Reference numeral 16 is a reference clock comparison means, 17 is a reference clock generation means, 20 is a CPU, 21 is a host, 26 is a rotation speed detector, 27 is a target reference clock comparison means, and 28 is a target reference clock generation means.

A conventional rotation control method for a disk device will be described with respect to the rotation control device for a disk device comprising the above components. First, a rotation control method of the disk device when the pickup 3 is following a track will be described.

The data on the disk 1 read by the pickup 3 is converted into a binary signal by the demodulation means 6 and sent to the PLL circuit 15. 2 in the PLL circuit 15
The reproduction clock synchronized with the value signal is extracted. Next, in the reference clock comparison means 16, the reproduced clock and the reference clock output from the reference clock generation means 17 are compared in frequency and phase. As a result, if the reproduction clock frequency is lower than the reference clock frequency, the command of the motor driving means 7 is increased to increase the rotation speed, and conversely, if the reproduction clock frequency is higher, the drive command is decreased to decrease the rotation speed. The motor rotation control (CLV control) is performed so that the frequency and the phase match and the linear velocity becomes constant.

Next, a rotation control method of the disk device at the time of moving the pickup (hereinafter, the movement will be referred to as seek) will be described. During the seek, the frequency of the reproduction clock that is synchronized with the reproduction signal changes rapidly, so that the PLL circuit 15 is unlocked and CLV control cannot be performed.

Therefore, the motor 2 is provided with a rotation speed detector 26, and the rotation speed of the motor 2 is controlled by using the obtained rotation speed information. The control at this time is performed by comparing the frequency and the phase between the clock synchronized with the rotation speed output from the rotation speed detector 26 and the rotation reference clock that determines the rotation speed of the motor 2, and comparing with the rotation speed synchronization clock. The motor 2 is rotated so that the rotation reference clock has the same frequency and phase.

When a seek command is sent from the host 21 such as a personal computer to the CPU 20, the CPU 20 obtains the motor rotation speed required for the seek target track from the address of the seek target track. Next, the rotation reference clock frequency required at that time is obtained from the motor rotation speed. The target reference clock generating means 28 outputs the rotation reference clock having the obtained frequency. A drive command is sent from the CPU 20 to the feed control means 5 to start seeking. The feed control means 5 moves the pickup feed mechanism 4 to move the pickup to the seek target track. When the seek is started, the rotation speed detector 26
A clock synchronized with the rotation of the motor output from is sent to the target reference clock comparison means 27. The target reference clock comparison means 27 compares the frequency and the phase between the rotation reference clock and the motor rotation speed synchronization clock. At this time, the motor rotation speed synchronization clock and the rotation reference clock have the same frequency and phase, and rotation control is performed so that the motor rotates at the rotation speed required for the seek target track.

When the pickup 3 reaches the seek target track, the switching means 14 is switched to perform the above-mentioned C when the pickup 3 is following the track.
LV control is performed (for example, it is disclosed in JP-A-59-186178).

[0014]

However, in the conventional configuration, the rotation speed detector 26 for detecting the rotation speed of the motor,
Since the target reference clock generating means 28 for generating the rotation reference clock of an arbitrary frequency is required, the device becomes complicated and the cost is increased.

Further, since the rotation reference clock can be set only in a stepwise manner, the motor cannot be accurately rotated at the required number of rotations in the seek target track, and the pickup reaches the seek target track to perform CLV control. There is also a problem that the motor cannot be immediately rotated at a normal rotation speed when the switching is performed.

The present invention solves the above-mentioned conventional problems, and simplifies the apparatus without adding components such as the rotation speed detector 26 and the target reference clock generating means 28, thereby reducing the cost. A rotation control method for a disk device that can realize a reduction and can immediately rotate the motor at a normal rotation speed when the pickup reaches a seek target track without deteriorating the responsiveness of the rotation control of the motor. The purpose is to provide a device.

[0017]

In order to solve the above-mentioned problems, a rotation control method for a disc apparatus according to the present invention provides a position on the information recording disc of a pickup for reproducing information on the information recording disc, and Based on the length of the recorded information reproduced from the information recording disc, the rotation speed of the information recording disc is obtained, and a motor rotation speed command determined in advance corresponding to this rotation speed and the position on the information recording disc. And the rotation speed of the information recording disk is controlled so that the difference between them is minimized.

Also, the rotation control device of the present invention reproduces information recorded on the information recording disk, a motor for rotating the information recording disk, a motor driving means for sending a rotation command to the motor. In a rotation control device for a disk device including a pickup, position detecting means for detecting the position of the pickup, and recording information length measuring means for measuring the length of recording information reproduced from the information recording disk by the pickup. A motor rotation speed calculation means for obtaining rotation speed information of the information recording disk based on the position information of the pickup detected by the position detection means and the length of the recording information measured by the recording information length measuring means; Rotation command generation means for generating a speed command and the motor rotation speed calculation means Rotation speed error amount extraction means for obtaining a rotation speed error amount by comparing the rotation speed information and the motor rotation speed command generated by the rotation command generation means, and a reference speed command generation for generating a reference speed command for reproducing recorded information. Means for comparing the length of the record information measured by the record information length measuring means with the record information reproducing reference speed command generated by the reference speed command generating means to obtain a record information reproducing speed error amount. An amount extracting means and a switching means for switching between a first control mode for minimizing the rotational speed error amount and a second control mode for minimizing the recorded information reproducing speed error amount in the rotation control of the motor. The configuration is provided.

[0019]

According to the method of the present invention, the motor rotation speed command is predetermined according to the position of the pickup. The rotational speed of the information recording disk is determined based on the position of the pickup on the information recording disk and the length of the recorded information when controlling the rotational speed of the information recording disk, and is compared with the motor rotational speed command. .

Further, according to the structure of the present invention, when the pickup moves a long distance, the switching means sets the first control mode for minimizing the rotational speed error amount obtained by the rotational speed error amount extraction means. Select to control the rotation speed of the information recording disc.

When the pickup moves a short distance,
The switching means controls the rotation speed of the information recording disk by selecting the second control mode which minimizes the recording information reproduction speed error amount obtained by the recording information reproduction error amount extraction means.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a rotation control device for a disk device according to a first embodiment of the present invention. Figure 1
In the figure, 1 is a disk, 2 is a motor, 3 is a pickup, 4 is a pickup feed mechanism, 5 is a feed control means, and 6
Is demodulation means, 7 is motor drive means, 8 is a track counter, 9 is a data interval counter, 10 is position detection means, 1
1 is a data interval measuring means as a recorded information length measuring means,
Reference numeral 12 is a motor rotation speed calculation means as motor rotation speed calculation means, 13 is a rotation speed error amount extraction means, 14 is a switching means, 15 is a PLL circuit, 16 is a reference clock comparison means, 17 is a reference clock generation means, and 18 is Number of clocks
A motor rotation speed conversion table, 19 is rotation command generating means,
20 is a CPU, 21 is a host, 22 is a count clock generating means, and 25 is a drive command generating means.

FIG. 2 is a flow chart showing a rotation control method of the disk device according to the first embodiment of the present invention. In addition,
The method of controlling the rotation of the motor when the pickup 3 is following the track is the same as that of the conventional example, and therefore will be omitted.

A method of controlling the rotation of the disk device at the time of seeking will be described. Assuming that the pickup 3 is located in the innermost track where the first frame data shown in FIG. 7 is present, 3T when the rotation speed of the motor 2 changes
The relationship between the number of clocks of the 3T signal and the number of revolutions of the motor 2 at the time when the signal is counted by the count clock of a constant frequency generated by the count clock generating means 22 is checked in advance, and the clock number / motor rotation number conversion table 18 is created. However, it should be recorded in the memory inside the CPU 20. The radius distance on the innermost disk 1 is stored as X0 in the memory (step # 1). Before the seek starts, set the radial distance X1 on the disc 1 of the pickup 3 to
Based on the address information read from the disc 1 by the pickup 3, it is obtained and recorded in a memory (step #
2). When a seek command is sent from the host 21 to the CPU 20, the rotation command generating means 19 inside the CPU 20 finds the number of rotations of the motor 2 required for the seek target track, and uses the clock number / motor rotation number conversion table 18 created in advance. Then, the number of clocks of the 3T signal at that rotation speed is obtained (step # 3). A drive command is sent from the drive command generation means 25 inside the CPU 20 to the feed control means 5, and seek is started. The feed control means 5 moves the pickup feed mechanism 4 to move the pickup 3 to the seek target track (step # 4). When the seek operation is started, the track counter 8 counts the number of times the pickup 3 has crossed the track. Track count value is CPU
It is taken in by 20 and sent to the position detecting means 10. The position detecting means 10 multiplies the track count value by the track pitch value to obtain the movement amount X2 of the pickup 3 (step # 5). The pickup radial distance X (X = X1 + X2) is obtained from the pickup movement amount X2 and the pickup radial distance X1 before the start of seek (step # 6). At the same time, read the data on disk 1,
The interval of the data binarized by the demodulation means 6 is counted by the count clock of a constant frequency generated by the count clock generation means 22 (step # 7). The count value of the data interval is fetched by the CPU 20 and sent to the data interval measuring means 11. The operation of counting data intervals is repeated for each data, and here, for example, the intervals of all data for 8 frames are measured. If the pickup 3 crosses the track during this time, the steps # 5 and # 6 are performed to update the pickup radial distance X (step # 8). When the intervals of all the data for 8 frames are measured, the process proceeds to the next step (step # 9). Since the 3T data is the data with the shortest interval in EFM modulation, the data interval measuring means 11 uses the shortest-length record information extracting means provided therein to obtain the data with the shortest interval among the data of 8 frames. It is extracted as 3T data, and the interval of this 3T data is used as motor rotation speed information (step # 10). Here, the data for 8 frames is taken in because the sampling frequency for motor rotation speed detection is 1 kHz (the time for one frame is 1/7350).
Seconds, the time for 8 frames is about 1 msec. ) To increase the rotation control band of the motor to improve control responsiveness, and to increase the probability of capturing a large amount of data having a length of several frames or more and extracting 3T data. In the motor rotation speed calculation means 12, the clock number of the extracted 3T data is multiplied by X / X0, and the clock value counted at the point X at the current pickup position is used as the clock value at the point X0 at the innermost circumference. Convert (step # 11). FIG. 3 shows the relationship between the intervals of 3T data at points X and X0. In the CLV control, the data recording density on the disc is the same at any radial position on the disc, so the 3T data interval is also the same at any radial position on the disc as shown in FIG. Here, considering the case where the motor is rotating at a certain number of rotations regardless of the location of the pickup as shown in FIG. 3B, data is read at the same intervals as when reading 3T data at point X0. When attempting to read from the X point, data at a longer interval than the X0 point must be recorded at the X point. Since the ratio of the data interval is proportional to the circumference, it is also proportional to the radial distance of the disc. By multiplying the 3T data interval at the X point by X / X0, the data interval at the X0 point at that time can be obtained. After that, if the relationship between the data interval at the X0 point and the motor rotation speed is investigated, the rotation speed of the motor can be detected. In the rotational speed error amount extraction means 13, the calculated 3T data interval at the X point is X0.
The value converted into the number of clocks at the point is compared with the 3T clock number at the point X0 of the required number of rotations in the seek target track recorded in step # 3 to obtain the error amount (step # 12). The motor driving means 7 fetches the error data and issues a rotation operation command to the motor 2 so that the error amount becomes the minimum and the motor 2 rotates at the required rotation speed on the seek target track (step # 13). The motor 2 receives the rotation operation command and changes the motor rotation speed (step #
14). The operations from step # 5 to step # 14 are repeated (step # 15). When the pickup 3 reaches the seek target track, the switching means 14 is switched to perform the CLV control described in the conventional example when the pickup is following the track (step # 1).
6).

According to the method of the first embodiment, the 3T at the pickup position X on the disc is sought at the seek time.
The 3T data interval value in the innermost circumference X0 is obtained by multiplying the data interval by X / X0, and the 3T data interval value in the innermost circumference X0 at the rotation speed required for the seek target track is obtained.
By comparing with the data interval value and rotating the motor so that the error is minimized, even if there is no device such as a rotation speed detector, the response of the motor rotation control does not deteriorate and the pickup seeks the target. When a truck is reached, it is possible to immediately control the rotation of the motor so that it can always be rotated at the normal rotation speed.

The second embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a block diagram of a rotation control device for a disk device according to a second embodiment of the present invention. In FIG. 4, 1 is a disk, 2 is a motor, 3 is a pickup, 4 is a pickup feed mechanism, 5 is a feed control means, 6 is a demodulation means, 7 is a motor drive means, 8 is a track counter, 9 is a data interval counter, Reference numeral 10 is a position detecting means, 11 is a data interval measuring means as a recording information length measuring means, 12 is a motor rotation speed calculating means as a motor rotation speed calculating means, 13 is a rotation speed error amount extracting means, 14
Is a switching means, 15 is a PLL circuit, 16 is a reference clock comparison means, 17 is a reference clock generation means, 18 is a clock number / motor rotation number conversion table, 19 is a rotation command generation means, 20 is a CPU, 21 is a host, 22 Is a count clock generating means, 23 is a data reading error amount extracting means as a recording information reproducing error amount extracting means, 24 is a reference speed command generating means, and 25 is a drive command generating means.

Since the method of controlling the rotation of the disk device when the pickup 3 is following the track is the same as that of the conventional example, the description thereof will be omitted. A method of controlling the rotation of the disk device at the time of seeking will be described with reference to FIGS. Here, assuming that the pickup 3 is located in the innermost track where the first frame data exists, a 3T signal of a constant frequency generated by the count clock generating means 22 when the rotation speed of the motor 2 changes is generated. The relationship between the number of clocks of the 3T signal when counted by the count clock and the number of rotations of the motor 2 at that time is checked in advance, and the number of clocks
It is assumed that the motor rotation speed conversion table 18 is created and recorded in the memory inside the CPU 20.

In FIG. 5, as the initial setting, the radial distance on the innermost disk 1 is recorded as X0 in the memory (step # 101). When a seek command is sent from the host 21 to the CPU 20, the length of the seek distance is determined and the seek mode is set to the first control mode by the switching means 14 according to the seek distance and the selecting means provided therein. Switch to the second control mode (step # 102).

If it is determined in step # 102 that the seek distance is relatively long, a control method for a relatively long seek distance will be described later. Step # 102
If it is determined that the seek distance is relatively short in, the control method for a relatively short seek distance as the second control mode described below is performed.

If the seek distance is relatively short, the CPU 20
A drive command is sent from the internal drive command generation means 25 to the feed control means 5 to start seeking. The feed control means 5 moves the pickup feed mechanism 4 to move the pickup 3 to the seek target track (step # 103). When the seek is started, the pickup 3 reads the data on the disk 1 and the demodulation means 6 converts the read data into binary data. The binarized data is sent to the data interval counter 9, and the data interval is counted by the count clock having a constant frequency output from the count clock generating means 22 (step # 104). This operation is repeated for each data, and the intervals of all data for 8 frames are measured (step # 105). The measured count value is taken into the CPU 20, and the data interval measuring means 11
Sent to. In the data interval measuring means 11, the shortest length record information extracting means provided therein extracts the data having the shortest interval among the data of 8 frames as 3T data and records the number of clocks in the memory (step # 106). In the reference speed command generating means 24, 3 of the value obtained by counting the reproduction clock interval with the count clock is used.
A multiple value is obtained (step # 107). In the data read error amount extraction means 23, the triple value of the reproduction clock interval obtained by the reference speed command generation means 24 and the step # 10.
The number of clocks of the 3T data recorded in 6 is compared to obtain the error amount (step # 108). By performing a motor rotation control similar to the CLV control performed when the pickup 3 described in the conventional example is following a track, by comparing the 3T data interval with a tripled value of one clock interval of the reproduction clock. You can The motor driving means 7 takes in the error data and issues a rotation operation command to the motor 2 so that the error amount is minimized (step # 109). The motor 2 receives the rotation operation command and changes the motor rotation speed (step # 110).

The operations from step # 104 to step # 110 are repeated (step # 111). Pickup 3
When the seek target track is reached, the switching means 14
Is switched to perform CLV control performed when the pickup described in the conventional example is following the track (step # 112).

Next, if the result of determination in step # 102 is that the seek distance is relatively long, the control method shown in FIG. 6 is executed as the first control mode. Before the seek starts, set the radial distance X1 on the disc 1 of the pickup 3 to
Based on the address information read from the disc 1 by the pickup 3, it is obtained and recorded in a memory (step #
113). When a seek command is sent from the host 21 to the CPU 20, the CPU 20 obtains the number of rotations of the motor 2 required for the seek target track, and uses the clock number / motor rotation number conversion table 18 created in advance to obtain the number of rotations. Obtain the number of clocks of the 3T signal (step # 11
4). A drive command is sent from the drive command generation means 25 inside the CPU 20 to the feed control means 5, and seek is started. The feed control means 5 moves the pickup feed mechanism 4 to move the pickup 3 to the seek target track (step #
115). When the seek operation is started, the track counter 8 counts the number of times the pickup 3 has crossed the track. The track count value is fetched by the CPU 20 and sent to the position detecting means 10. In the position detecting means 10, the track count value is multiplied by the track pitch value to obtain the movement amount X2 of the pickup 3 (step # 11).
6). The radial distance X (X = X1 + X2) of the pickup 3 at the present time is obtained from the pickup movement amount X2 and the radial distance X1 of the pickup 3 before the start of seek (step # 1
17). At the same time, the data on the disk 1 is read, and the interval between the binarized data by the demodulating means 6 is counted by the count clock of a constant frequency generated by the count clock generating means 22 (step # 118). The count value of the data interval is fetched by the CPU 20 and sent to the data interval measuring means 11. The operation of counting data intervals is repeated for each data, and the intervals of all data for 8 frames are measured. If the pickup 3 crosses the track during this time, perform steps # 116 and # 117,
Update the pickup radial distance X (step # 11)
9).

When the intervals of all data for 8 frames are measured, the process proceeds to the next step (step # 120). In the data interval measuring means 11, the shortest length recording information extracting means provided therein extracts the data having the shortest interval among the data of 8 frames as 3T data, and the interval of this 3T data is rotated by the motor 2. It is used as numerical information (step # 121). The motor rotation speed calculation means 12 multiplies the clock number of the extracted 3T data by X / X0 and converts the clock value counted at the X point into the clock value when counted at the X0 point (step # 12).
2). The rotational speed error amount extraction means 13 converts the calculated 3T data interval at the X point into the number of clocks at the X0 point and the 3T at the X0 point of the required rotational speed in the seek target track recorded in step # 113. The amount of error is calculated by comparing with the number of clocks (step # 123).
The motor driving means 7 fetches the error data and issues a rotation operation command to the motor 2 so that the error amount becomes the minimum and the motor 2 rotates at the required number of rotations on the seek target track (step # 124). The motor 2 receives the rotation operation command and changes the motor rotation speed (step # 125). The operations from step # 116 to step # 125 are repeated (step # 126). When the pickup 3 approaches the seek target track, the switching means 14 is switched to control the rotation of the disk device when the seek distance is relatively short (step # 102 to step # 112 in FIG. 5).
Carry out.

According to the method of the second embodiment, at the time of seeking, when the pickup is away from the seek target track, the theta is controlled to rotate at the required number of revolutions on the seek target track, and the pickup is picked up. When approaching the seek target track, the control mode is switched so as to perform the CLV control, so that when the pickup reaches the seek target track, the response of the motor rotation control is not deteriorated and the pickup is moved. When the seek target track is reached, the motor can be immediately and always rotated at the normal rotation speed.

[0035]

According to the present invention, the motor rotation speed command is determined in advance in correspondence with the position of the pickup, and the rotation speed of the information recording disk is controlled when the rotation speed of the information recording disk is controlled. It is obtained based on the position of the upper pickup and the length of the recorded information, and can be compared with the motor rotation speed command.

When the pickup moves a long distance, the switching means selects the first control mode which minimizes the rotational speed error amount obtained by the rotational speed error amount extraction means, and selects the information recording disk. You can control the rotation speed of.

When the pickup moves a short distance,
The switching means can control the rotation speed of the information recording disk by selecting the second control mode which minimizes the recording information reproduction speed error amount obtained by the recording information reproduction error amount extraction means.

Therefore, cost reduction can be realized by simplifying the device without adding components such as a rotation speed detector and target reference clock generating means as in the conventional case. Further, the responsiveness of the rotation control of the motor is not deteriorated, and when the pickup reaches the seek target track, the motor can always be immediately rotated at the normal rotation speed.

As a result, the access time of the recording surface on the disc can be shortened and the information on the disc can be read out quickly.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a rotation control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a rotation control method of the embodiment.

FIG. 3 is a structural diagram of 3T data recorded on a disc.

FIG. 4 is a configuration diagram of a rotation control device according to a second embodiment of the present invention.

FIG. 5 is a flowchart of the same embodiment when the seek distance is short.

FIG. 6 is a flowchart of a long seek distance according to the first embodiment.

FIG. 7 is a structural diagram of data recorded on a disc of an optical disc device.

FIG. 8 is a block diagram of a conventional rotation control device.

[Explanation of symbols]

 10 Position Detecting Means 11 Data Interval Measuring Means 12 Motor Rotational Speed Calculating Means 13 Rotating Speed Error Amount Extracting Means 14 Switching Means 19 Rotation Command Generating Means 23 Data Reading Error Amount Extracting Means 24 Reference Speed Command Generating Means

Claims (7)

[Claims] 1. A rotational speed of the information recording disc based on a position of a pickup for reproducing information on the information recording disc on the information recording disc and a length of recorded information reproduced from the information recording disc by the pickup. Then, this rotation speed is compared with a motor rotation speed command determined in advance corresponding to the position on the information recording disk, and the rotation speed of the information recording disk is adjusted so that the difference between them is minimized. A rotation control method of a disk device for controlling. 2. An information recording disk has information recorded on a helix of a recording surface, and the rotational speed of the information recording disk is adjusted so that the recording density in the tangential direction is the same at all positions where the information is recorded. The method of controlling rotation of a disk device according to claim 1, wherein the rotation is controlled. 3. The length of the record information used when calculating the rotation speed of the information recording disc is the shortest among the lengths of at least one record information reproduced from the recorded information by a pickup. The rotation control method for a disk device according to claim 2. 4. A disk device comprising an information recording disk, a motor for rotating the information recording disk, a motor driving means for sending a rotation command to the motor, and a pickup for reproducing recorded information on the information recording disk. In the rotation control device, position detecting means for detecting the position of the pickup, recording information length measuring means for measuring the length of the recording information reproduced from the information recording disk by the pickup, and the position detecting means are used for detection. Motor rotation speed calculation means for obtaining rotation speed information of the information recording disk based on the position information of the pickup and the length of the recording information measured by the recording information length measuring means, and a rotation command generation for generating a motor rotation speed command. Means, rotation speed information obtained by the motor rotation speed calculation means, and the rotation command Rotational speed error amount extraction means for obtaining a rotational speed error amount by comparing with a motor rotational speed command generated by the generation means, reference speed command generation means for generating a reference speed command for reproducing recorded information, and the recorded information length measurement. The recording information reproduction error amount extraction means for obtaining the recording information reproduction speed error amount by comparing the length of the recording information measured by the means with the recording information reproduction reference speed command generated by the reference speed command generation means; In the rotation control, a rotation control device for a disk device provided with a switching means for switching between a first control mode for minimizing the rotation speed error amount and a second control mode for minimizing the recording information reproduction speed error amount. . 5. The information recording disk according to claim 4, wherein the information is recorded on a helix of the recording surface, and the recording density in the tangential direction on the helix is the same at all positions where the information is recorded. Disk drive rotation controller. 6. The recorded information length measuring means comprises a shortest length recorded information extracting means for extracting the shortest of the lengths of at least one or more recorded information reproduced by a pickup from the recorded information. The rotation control device for a disk device according to claim 5. 7. The switching means includes a selection means for selecting a first control mode for long-distance movement of the pickup and a second control mode for short-distance movement of the pickup. A rotation control device for a disk device according to claim 6.