JPH10149615A - Disk player - Google Patents

Abstract

PROBLEM TO BE SOLVED: To read out data from a disk having little eccentricity at high speed and to read out data from a disk having large vibration due to eccentricity in automatically decelerating linear velocity and reducing the vibration accordingly. SOLUTION: The disk 14 is rotated by a spindle motor 12. The data is read out of the disk 14 by a pickup 16. The pickup 16 is moved in the radial direction, while the spindle motor 12 is controlled to change the revolving speed of the disk 14 in accordance with a position of the pickup 16 by a system control part 18. When the vibration more than a prescribed value is detected, a detecting signal is outputted by an acceleration sensor 24. Moreover, the disk 14 can be rotated at plural linear velocities, and also when an output of the detecting signal is detected at the time of rotating the disk 14 at one linear velocity, a linear velocity at the time of reading out the data is lowered than this one linear velocity by the system control part 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a disk player for reading data from a compact disk (CD).

[0002]

2. Description of the Related Art Recently, a CD is widely used as an external storage medium of computer equipment, such as a CD-ROM, because it has a larger capacity than a conventional floppy disk. And a CD that reads data from such a CD
The reading speed (data transfer speed) of the drive device, that is, the disk player, has been increased to double speed, quadruple speed,... With the improvement of the processing speed of the computer equipment. It became.

[0003]

However, the conventional disk player has the following problems. Data is recorded on the disc based on a recording method called CLV (Constant Linear Velocity). In this recording method, the linear velocity is constant, and each time the pickup is moved in the radial direction of the disk, it is necessary to change the rotation speed of the disk according to the position. That is, when data is read from the outer circumference of the disk, the rotation speed of the disk is reduced, and when data is read from the inner circumference, the rotation speed of the disk is increased to maintain the data amount per unit time to be read. It should be noted that even in a disk recorded by the CLV method, a clock included in the read data is extracted, and data is sampled based on this clock to rotate the disk at a constant rotational speed (CAV: Constant Angular Veloc).
)), that is, data can be read even when the linear velocities are different between the inner circumference and the outer circumference. This is called a CAV method.

For this reason, especially in the case of the CLV system, when the reading speed of the disk player is to be increased as described above, the number of revolutions especially at the inner circumference of the disk becomes extremely high. For example, in the case of 12-times speed, the number of rotations on the inner circumference
60 rpm (2400 rpm on the outer circumference), the number of revolutions on the inner circumference is 4240 rpm in the case of 8 × speed (1600 rpm on the outer circumference)
). On the other hand, discs that can be rotated at high speed are mass-produced by resin molding once the mold is formed, but naturally not all products can be molded to exactly the same dimensions. The size of the individual products always varies within the range, and the center of gravity of the disk is not always the center of rotation. That is, the disk may be eccentric. In addition, the surface of the majority of discs are printed with characters or patterns indicating the contents of the disc, and in some cases, the user himself puts a label on the surface of the disc for management reasons. It is no exaggeration to say that most disks are more or less eccentric when considered.

[0005] When such an eccentric disk is rotated, vibration always occurs. Particularly, in the case of high-speed rotation such as the number of rotations of the disk on the inner circumference of the disk at 12-times speed, the vibration is considerably large. Becomes From the viewpoint of the disk player, the vibration adversely affects the focus servo and the tracking servo for the pickup, and causes a large number of read errors. As a result, there is a problem that a disk that is eccentric and has a large amount of vibration during rotation cannot be read. Also, this vibration adversely affects a hard disk which is often mounted in the same computer device together with the disk player. Particularly, in the case of a hard disk, there is a problem that the operation becomes unstable and the data cannot be read or written because the hard disk is more vulnerable to vibration than the disk player. In addition, there is also a problem that vibration is transmitted to the computer device and chatter is generated, thereby deteriorating the product image for the user.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above-mentioned problems. It is an object of the present invention that a disk with little eccentricity can read data at a high speed, and a disk with large vibration due to eccentricity automatically adjusts a linear velocity and a rotation speed. An object of the present invention is to provide a disk player which can read data with a reduced speed and reduced vibration.

[0007]

To solve the above-mentioned problems, the present invention has the following arrangement. That is, the invention according to claim 1 includes a spindle motor for rotating a disk on which data is recorded, a pickup for reading the data from the disk, and moving the pickup in the radial direction of the disk, and moving the pickup to the position of the pickup. A disk controller comprising a system control unit that controls the spindle motor in accordance with the rotation of the disk and changes the number of rotations of the disk. The system control unit is capable of rotating the disk at a plurality of linear velocities, and when detecting the output of the detection signal when rotating the disk at one linear velocity, the system control unit The linear velocity at the time of reading is set to a linear velocity lower than the one linear velocity. By adopting this configuration, the system control unit can automatically reduce the linear velocity when the vibration detected through the vibration detecting means is a predetermined vibration or more, and can read even an eccentric disk with much vibration. Becomes possible.

According to a fourth aspect of the present invention, there is provided a spindle motor for rotating a disk on which data is recorded, and a system control unit for controlling the rotation speed of the spindle motor to rotate the disk at a predetermined rotation speed. A disk player having vibration detection means for outputting a detection signal when a predetermined or more vibration is detected, wherein the system control unit can rotate the disk at a plurality of rotation speeds When the output of the detection signal is detected when the disk is rotated at one rotation speed, the rotation speed at the time of reading the data is set to a rotation speed lower than the one rotation speed. And By adopting this configuration, the system control unit can automatically reduce the rotation speed when the vibration detected through the vibration detection means is a predetermined level or more, and can read even an eccentric disk with much vibration. Becomes possible.

[0009]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. First, the configuration of the disc player 10 will be described with reference to FIG. 1, and also the basic operation will be described. The spindle motor 12 rotates a disk 14 on which data is recorded. Pickup 1
Numeral 6 irradiates the disk 14 with laser light and reads data from the disk 14. The system control unit 18 is configured using a microcomputer and a memory, and controls the pickup feed mechanism 20 to move the pickup 16 in the radial direction of the disk 14. Pickup 1
There is also a case where a command of focus servo or tracking servo is given to 6. Also, the spindle motor 12 is controlled according to the position of the pickup 16 to change the rotation speed of the disk 14. In addition, the signal processing circuit 22
Switching between LV operation and CAV operation and CLV
At the time of operation, a clock corresponding to the linear velocity at which reading is being performed is output. The memory stores a program that defines the operation and a data table that indicates the number of rotations on the inner circumference at each linear velocity during the CLV operation as described below.

In the CLV operation mode, the signal processing circuit 22 demodulates data from a signal output from the pickup 16 based on a clock received from the system control unit 18 and outputs the data. In the CAV operation mode, a clock is first extracted from a signal output from the pickup 16, and data is demodulated and output based on the clock. The vibration detecting means is configured by using an acceleration sensor 24 using a piezo element as an example, detects a vibration generated in the disk player 10, and detects a vibration equal to or more than a predetermined vibration (vibration limit) set in advance. In this case, a detection signal is output to the system control unit 18.

Next, the operation will be described. At first,
The basic operation principle will be described. The characteristic point of the disk player 10 is to detect a vibration when the eccentric disk 14 is rotated, and when the vibration is equal to or more than a predetermined vibration, when the reading operation by the CLV system is performed, the vibration is detected. The point is that the linear velocity is reduced or the data is read by switching to the CAV method at a constant rotation speed less than the predetermined vibration before reaching the predetermined vibration during the reading operation by the CLV method. Further, in the case of a read operation by the CAV method, the number of rotations is reduced to read data. As a result, it becomes possible to read even a disc 14 with many eccentricities, which has been impossible to read due to a large number of read errors in the conventional disc player. In addition, the vibration generated by the eccentric rotation of the disk 14 can be reduced, so that other devices, for example, a hard disk can stably read and write data.

Next, the operation will be described in detail with reference to FIGS. As shown in FIG. 2, the outline flow of the operation determines the reading operation mode in advance (step 10).
0), the reading operation of the disk 14 is performed according to the determined operation mode (step 200). This reading operation mode is a kind of reading operation, that is, the CLV method or C type.
There are several types depending on the AV system, and each operation mode will be described below.

First, the operation mode determination flow when the reading operation is performed by the CLV method will be described with reference to FIGS. After the disk 14 is mounted in the disk player 10, the system control unit 18 first reads data of the inner disk rotation speed at the fastest linear velocity from the CLV data table (see FIG. 5) in the memory, and reads the rotation speed. It is stored as Z (step 102). Next, the disk 14 is rotated at the rotation speed Z (step 104), and it is detected whether or not a detection signal is output from the acceleration sensor 24 at this time (step 106).

If a detection signal is detected in step 106, the data of the rotation speed of the disk 14 at the inner circumference at the linear speed which is one step lower is read from the memory (step 108), and a new rotation speed Z is set again. Steps 104 to 106 are repeated to obtain a linear velocity at which no detection signal is detected. In step 106,
When the linear velocity at which the detection signal is not detected is obtained, it is selected whether reading is performed only by the CLV method or reading is performed by using both the CLV method and the CAV method (step 11).
0).

When the reading operation by the CLV system alone is selected, the disk 14 is read at the linear velocity (for example, 8 × speed which is one step lower than 12 × speed) as shown in Pattern 1 of FIG. (Step 112). In this case, even at the inner circumference where the rotation speed of the disk 14 becomes the highest at the linear velocity, the magnitude of the vibration can be less than the predetermined vibration, and the linear velocity becomes the maximum velocity (for example, 1
2x speed), but the disk 1
4 can be avoided. Also, since the vibration is reduced, there is no adverse effect on other devices and the hard disk.

When the reading operation using both the CLV system and the CAV system is selected, as shown in pattern 2 in FIG. 4, the disk is driven at the highest linear velocity (12 × speed in the present embodiment) from the outer periphery to the middle. 14 is read.
The system control unit 18 constantly detects the rotation speed of the disk 14. If the vibration detected in step 104 reaches the rotation speed Z on the inner circumference at a linear velocity within the allowable range, the reading operation mode by the CAV method is performed. Then, the data is read in a state where the rotation speed is held until the inner circumference (step 114). In the case of the disk 14 with little eccentricity in step 106, since the detection signal is not detected even at the highest linear velocity (12 times speed), the operation directly proceeds to step 110 without performing the operation of step 108.
In this case, in step 110, the linear velocity at 12 × speed from the outer circumference to the inner circumference can be selected without any choice.
The reading operation of the LV system is performed.

Further, in the above-described embodiment, the case where the vibration level is equal to or less than the predetermined vibration when the linear velocity is set to one paragraph from the 12 × speed to the 8 × speed has been described, but depending on the degree of eccentricity of the disk 14, In some cases, it may be necessary to reduce the linear velocity when reading at 6 × speed or 4 × speed.
In this embodiment, as an example, it has been described that the 12 × speed is the highest linear velocity. However, in the case where the linear velocity further increases in the future, and the vibration caused by the rotation of the eccentric disk becomes larger, the present invention will be described. More effective.

Second, a description will be given of a flow of determining an operation mode when the reading operation is performed only by the CAV method.
In this case, in step 100 of FIG. 2, the system control unit 18 detects the presence or absence of a detection signal while gradually lowering the rotation speed of the disk 14 from the highest rotation speed, and determines the rotation speed at which no detection signal is detected. And step 2
The reading operation of 00 is performed on the disk 1 at the obtained rotation speed.
Read data while rotating 4. Therefore, the magnitude of the vibration generated by the rotation of the disk 14 can be made smaller than the predetermined magnitude of the vibration, and the disk 1 cannot be read at all at the highest rotational speed due to the vibration.
Also, the reading of data 4 can be automatically reduced to an appropriate number of revolutions and data can be read.

As described above, various preferred embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and it is noted that many modifications can be made without departing from the spirit of the invention. Of course.

[0020]

When the disk player according to the present invention is used, the system control section automatically reduces the linear velocity and the number of revolutions when the vibration detected by the vibration detecting means is a predetermined vibration or more. Operation can be performed,
It is possible to read even an eccentric disk whose vibration increases when rotated at high speed. Also, no matter what kind of disk is used, the vibration generated by the rotation of the disk can be suppressed to less than the predetermined vibration, and the influence on other devices such as a hard disk incorporated in the same housing with the disk player can be obtained. This has the effect of reducing noise.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a disc player according to the present invention.

FIG. 2 is a flowchart showing an outline of the operation of the disc player of FIG. 1;

FIG. 3 is a flowchart for determining a reading operation mode in FIG. 2;

FIG. 4 is a graph showing the relationship between the position of a pickup and the number of rotations of the disk when reading by the disk player of FIG. 1;

FIG. 5 is a CLV data table stored in a memory.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Disc player 12 Spindle motor 14 Disk 16 Pickup 18 System control part 24 Acceleration sensor

Claims (6)

[Claims] A spindle motor for rotating a disk on which data is recorded; a pickup for reading the data from the disk; a pickup for moving the pickup in a radial direction of the disk; And a system control unit that changes the number of rotations of the disk.When a vibration equal to or more than a predetermined value is detected, the system control unit includes a vibration detection unit that outputs a detection signal. It is possible to rotate the disk at a plurality of linear velocities, and when the output of the detection signal is detected when the disk is rotated at one linear speed, a line at the time of reading the data is used. A disk player, wherein the speed is lower than the one linear speed. 2. The system control unit according to claim 1, wherein the system control unit detects the presence or absence of the detection signal by previously rotating the disk at a maximum rotation speed of the disk at one linear velocity, and when the detection signal is detected, 2. The disk player according to claim 1, wherein a linear velocity at the time of reading the data is lower than the one linear velocity. 3. The system control section rotates the disk at one linear velocity while moving the pickup while detecting the output of the detection signal in advance, and when the detection signal is detected, the disk at that time is detected. When the data is read from the disk at the one linear velocity, the rotation speed of the disk or the position of the pickup does not reach the vibration start rotation speed or the vibration start position. 2. The disk player according to claim 1, wherein the disk is rotated at a constant rotation speed less than the vibration start rotation speed. 4. A disk player comprising: a spindle motor for rotating a disk on which data is recorded; and a system controller for controlling the rotation speed of the spindle motor to rotate the disk at a predetermined rotation speed. When the vibration of the disk is detected, the system control unit includes a vibration detection unit that outputs a detection signal, and the system control unit is capable of rotating the disk at a plurality of rotation speeds, and the disk is rotated at one rotation speed. A rotation speed at the time of reading the data is set to a rotation speed lower than the one rotation speed when an output of the detection signal is detected at the time of rotating the disk. 5. The system control unit according to claim 1, wherein the system control unit detects the presence or absence of the detection signal by rotating the disk in advance at one rotation speed, and when the detection signal is detected, the system control unit reads the data when reading the data. 5. The disc player according to claim 4, wherein the number of revolutions is lower than the one number of revolutions. 6. The disk player according to claim 1, wherein said vibration detecting means is an acceleration sensor.