JPH1031862A - Reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a reproducing linear velocity according to a discriminated area, to speed up access operation and to reduce power consumption by making the speed difference of a disk rotational speed lower than a rotational speed difference between inner/outer peripheries. SOLUTION: Plural areas are set in the radial direction of a disk 90, and the operation switching the linear velocity at every area and reproducing is executed. Thus, the table data for switching the linear velocity are stored in a memory 17, and the area is set by an address value, and the linear velocities in respective areas are set. At this time, the no. of the address of a disk innermost side, the address of an outermost side are made nLAST, and n1-n4 show the certain specified addresses on the disk.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a linear velocity (CL)
The present invention relates to a reproducing apparatus for a disk-shaped recording medium on which information is recorded by the V) method.

[0002]

2. Description of the Related Art At present, disk media on which information is recorded by the CLV method, such as CD-DA (CD digital audio) and CD-ROM, are widely used.
In the reproducing apparatus for such a CLV optical disk, in order to appropriately read recorded information, the disk rotational speed, that is, the rotational speed of the spindle motor is appropriately controlled in accordance with the reproducing position on the disk, and the linear velocity is controlled. It needs to be kept constant.

[0003] Of course, the normal linear velocity (about 1.
When 3m / s) is set to 1x speed, high-speed playback such as 2x speed and 4x speed may be performed. In this case, too, naturally, the rotation speed of the spindle motor is variably controlled for constant linear speed control. I have. The rotation speed for keeping the linear velocity constant is inversely proportional to the radius of the disk. At the time of reproduction scanning at the innermost circumference of the disk, the rotation speed is about 2.5 times that at the time of reproduction scanning of the outermost circumference of the disk.

FIG. 8 shows the relationship between the position in the disk radial direction and the rotational speed. The position on the innermost peripheral side is an address n0,
The position on the outermost side is an address nLAST. It is shown that if reproduction scanning is performed from the innermost side to the outermost side at a certain CLV speed (h-times speed), a rotational speed difference Vd0 occurs between the innermost side scanning and the outermost side scanning.

[0005]

However, the occurrence of such a relatively large difference in rotational speed causes a problem in that the access operation time is prolonged and the power consumption is increased.

At the time of an access operation, the reproduction scanning position is often largely moved in the radial direction of the disk. For example, an access from the outer peripheral position to the inner peripheral position of the disk, and conversely, an access from the inner peripheral position to the outer peripheral position with a large movement amount in the disk radial direction are frequently performed.

At the time of such an access, in order to reproduce an address or data at a position of an access destination, it is necessary to set a linear velocity suitable for the position. In other words, if the amount of movement at the time of access is large, the rotational speed difference between the position before access and the position after access has an appropriate linear velocity is large, and reading after access is possible only with rotation. Since the speed is set, the access time becomes longer by waiting for the rotation speed to be set. Further, since the spindle motor is accelerated or decelerated every time the access is performed, a large amount of power is consumed for driving the spindle motor.

Further, the transfer rate has been increased,
When high-speed playback such as 2x speed, 4x speed, and 8x speed is performed as described above, the difference in rotation speed between the inner and outer circumferences of the disc becomes even greater, and the problem of longer access time and increased power consumption. Is a bigger problem.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a reproducing apparatus for a disk-shaped recording medium of the CLV system, which can shorten the access time and reduce the power consumption. The purpose is to:

For this reason, as a reproducing apparatus, an area discriminating means for dividing and setting an area in a radial direction on a disk and discriminating an area where a reproducing scan is being performed;
Reproduction control means for switching and controlling the reproduction linear velocity in accordance with the area determined by the area determination means.

Further, the reproduction control means does not switch the linear velocity in the entire area on the disk due to the difference in speed between the disk rotational speed during the innermost peripheral scan of the disk and the disk rotational speed during the outermost peripheral scan of the disk. The reproduction linear speed is switched and controlled so as to be smaller than the rotation speed difference between the inner and outer circumferences in the case.

That is, the area is divided in the disk radial direction,
In each area, reproduction is performed at a predetermined linear velocity, but the linear velocity is changed for each area. by this,
The rotational speed difference between the inner and outer sides of the disk is reduced, and the rotational speed settling time and the amount of acceleration / deceleration after access are reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A reproducing apparatus according to an embodiment of the present invention will be described below with reference to FIGS. FIG.
FIG. 1 is a block diagram of a reproducing apparatus of the present example corresponding to a CD-ROM which is a CLV optical disk. The disk 90 indicates a CD-ROM loaded in the playback device.

The disk 90 is driven to rotate at a constant linear velocity (CLV) by the spindle motor 1 during a reproducing operation. Then, data recorded in a pit form on the disk 90 is read by the optical head 2 and supplied to the RF amplifier 5. The optical head 2 includes a laser diode as a laser output unit, an optical system including a polarizing beam splitter and an objective lens, and a detector for detecting reflected light. The objective lens 2a is held by the biaxial mechanism 3 so as to be displaceable in the radial direction of the disk and in the direction of coming into contact with and separating from the disk. The entire optical head 2 can be moved in the disk radial direction by a sled mechanism 4.

A reproduction RF signal, a tracking error signal, a focus error signal, and the like are extracted from the information detected from the disk 90 by the optical head 2 by the reproduction operation, by a matrix calculation process in the RF amplifier 5. The reproduction RF signal extracted by the RF amplifier 5 is subjected to binarization processing and edge detection processing in a data slicer / edge detection unit 6, and a binarized signal, that is, an EFM signal is supplied to a decoder 9. An edge detection signal by the edge detection processing is used to generate a recovered clock by a PLL circuit 11.
Supplied to Based on the edge detection signal of the EFM signal, the PLL circuit 11 reproduces a reproduction clock C synchronized with the EFM signal (that is, proportional to the CLV speed of the spindle motor).
K is generated and supplied to necessary parts. The output of the data slicer / edge detector 6 is also supplied to the servo processor 7.

The tracking error signal and focus error signal extracted by the RF amplifier 5 are
Supplied to The servo processor 7 receives the supplied tracking error signal, focus error signal, and the system controller 1 constituted by a microcomputer.
Various servo drive signals are generated according to a track jump command, an access command, and the like from the controller 6, and the two-axis mechanism 3 and the thread mechanism 4 are driven by the servo driver 8 to execute focus and tracking control.

The data slicer / edge detector 6 outputs the EF
In the decoder 9 to which the M signal is supplied, EFM demodulation, CIR
By performing processes such as C decoding and CD-ROM decoding, so-called decoded reproduction data (data file or the like) is obtained. The reproduction data is supplied to a host computer connected via the interface unit 10. The decoder 9 also extracts the address Ad and other sub-codes.
Supplied to

Various operations during reproduction are controlled by a system controller 16 formed by a microcomputer. For example, playback start, end, track access,
Operations such as fast-forward playback and fast-reverse playback are performed by the system controller 16 via the servo processor 7.
It is realized by controlling the operation of. Communication with the host computer is performed via the interface unit 10, and the system controller 16 controls a predetermined data file reproduction operation from the disk 90 in response to an access request from the host computer.

The memory 17 stores data / coefficients / tables for various processes of the system controller 16 and the like. In the case of this example, a data table for CLV speed switching described later is stored.

In the reproducing apparatus of this embodiment, the spindle motor 1
Although the rotation speed is controlled by the CLV method, variable speed reproduction such as high-speed reproduction at a so-called 1 × speed is also possible, that is, the rotation speed of the spindle motor 1 can be switched to a different linear speed state. That is, a servo system for maintaining the rotation speed of the spindle motor 1 at a certain CLV speed is configured, and the CLV speed to be maintained can be varied.

First, a speed control unit 14 is provided for CLV servo of the spindle motor 2. Speed control unit 14
Are supplied with a reproduction clock CK and a reference clock CK _REF from a reference frequency setting circuit 13 that operates based on a master clock MCK from a crystal clock generator 12.

The reference clock CK _REF is a certain CL
The clock has a frequency corresponding to the V speed. Also PLL
The reproduction clock CK from the circuit 11 has a frequency corresponding to the CLV speed (reproduction linear velocity) of the spindle motor 2.
Therefore, in the speed control unit 14, the reference clock CK
An error between _REF and the reproduction clock CK is detected, and this is output as a spindle error signal SPE. When the spindle motor driver 15 applies driving power to the spindle motor 1 based on the spindle error signal SPE, the CLV servo system of the spindle motor 1 functions.

In such a CLV servo system, the system controller 16 controls the reference frequency setting circuit 13 to vary the frequency of the reference clock CK _REF , thereby realizing a CLV speed servo that is faster or slower than a single speed. In addition, even in the case of variable-speed playback other than 1x speed, P
The reference frequency setting circuit 13 variably sets the center frequency of the PLL circuit 11 according to the double speed value so that the LL circuit 11 can perform good locking. When performing variable-speed reproduction, the system controller 16 also switches the frequency characteristics of the equalizer in the RF amplifier 5 according to the shift value.

When the acceleration / deceleration is forcibly performed on the spindle motor 1, a CLV servo loop is opened, and the system controller 16 supplies the spindle kick / brake signal SPKB to the spindle motor driver 15. The spindle motor driver 15 applies acceleration power or deceleration power to the spindle motor 1 based on the spindle kick / brake signal SPKB to accelerate or decelerate the rotation speed of the spindle motor 1.

In the reproducing apparatus of this embodiment configured as described above, a plurality of areas are set in the radial direction of the disk 90, and the operation of switching the linear velocity for each area to perform the reproduction is performed. For this purpose, the memory 17 stores, for example, table data for switching linear velocities as shown in FIG. 2, and sets an area by an address value and sets a linear velocity in each area. Here, the innermost address of the disk is n0, the outermost address is nLAST, and n1 to n
Reference numeral 4 indicates a specific address on the disk.

In this case, the innermost area from the address n0 to the address n1, the address n1 + 1 to the address n2, the address n2 + 1 to the address n3, the address n3 + 1 to the address n4, the address n4 + 1 to the address nLAST, and the area on the disk. Information for division setting into five areas of 1 to 5 is stored. Then, as linear velocities corresponding to each of the regions 1 to 5,
hx speed, h + 0.5x speed, h + 1.0x speed, h + 1.5x speed,
Each linear velocity of h + 2.0 times speed is set.

The system controller 16 controls the disk 9
The address detected at the time of the reproducing operation of 0, that is, the address of the current reproducing scanning position, is compared with the table data in FIG. Set. For example, if the area 1 is being reproduced, the reference frequency setting circuit 13 is caused to execute the operation for h-times speed reproduction, and the detected address exceeds the address n1 and the reproduction scan enters the area 2. Upon detection, the operation of the reference frequency setting circuit 13 is switched to an operation for h + 0.5 speed reproduction.

FIG. 3 shows the relationship between the rotational speed and the position in the disk radial direction realized by such an operation. FIG.
, NLAST, n1 to n4 in FIG.
Is the address at the position on the disk indicated on the horizontal axis.

Area 1, ie, from address n0 to address n
In the section up to 1, the linear velocity is h-speed (1 if h = 1)
(Double speed if h = 2), and reproduction is performed. In the area 2, that is, in the section from the address n1 + 1 to the address n2, the linear velocity is h + 0.5 times speed (if h = 1,
(1.5 times speed, 2.5 times speed if h = 2). In the area 3, that is, in the section from the address n2 + 1 to the address n3, the linear velocity is set to h + 1 times speed (double speed when h = 1, triple speed when h = 2), and reproduction is performed. Similarly, from address n3 + 1 to address n4
In the area 4 up to, the linear velocity is h + 1.5 times speed, address n4
In region 5 from +1 to address nLAST, the linear velocity is h +
Reproduction is performed at double speed.

As a result, the change in the rotational speed in the radial direction of the disk is as shown in the figure, and the speed difference Vd1 between the rotational speed at the innermost periphery of the disk and the rotational speed at the outermost periphery of the disk is the normal difference shown in FIG. The speed difference Vd0 in CLV reproduction can be made smaller.

The fact that the speed difference Vd1 is smaller than the conventional speed difference Vd0 means that the speed adjustment width of the spindle motor 1 to be adjusted by acceleration or deceleration at the time of access can be reduced. It is possible to shorten the time required for the settling process for obtaining a suitable rotation speed. As a result, the access time can be reduced. In addition, the fact that the acceleration or deceleration width can be reduced can also reduce power consumption for acceleration and deceleration, and promote power saving.

The rotation speed switching control as shown in FIG. 3 is performed by having the table data as shown in FIG. 2. However, the disk radial direction area setting and the linear velocity setting method in each area are as follows. Various examples are conceivable. 4 to 6 show four more examples.

FIG. 4 shows an example in which the area is set more finely. The area is divided into ten areas with certain addresses n11 to n19 as boundaries. By switching the linear velocity in each area at higher speeds toward the outer peripheral area, the relationship between the scanning position in the disk radial direction and the rotational speed of the spindle motor 1 is shown in the figure. The speed difference is Vd2. That is, the speed difference is made smaller than that in the example of FIG. 3 described above, and the shortening of the access time and the reduction of the power consumption are promoted.

The example of FIG. 5 is effective when it is desired to increase the transfer rate on the inner circumference side of the disk. In other words, at a position close to the inner peripheral side, the area is finely divided with certain addresses indicated by n21 to n24 as boundaries, and the linear velocity is switched in each area. In this case, the rotation speed is maintained at a high speed in a range close to the inner peripheral side, whereby an improvement in the transfer rate on the inner peripheral side is realized.

In the example of FIG. 6, the transfer rate on the inner circumference is improved as shown in FIG. 5, and the speed difference between the inner and outer circumferences is reduced as compared with FIG. That is, in the range near the inner circumference, the area is finely divided by using certain addresses indicated by n21 to n24 as boundaries as in FIG. 5, and in the range closer to the outer circumference, certain addresses denoted by n25 to n28 are divided. The region is finely divided as boundaries. The divided areas are 9 areas in total. The relationship between the scanning position in the disk radial direction and the rotation speed of the spindle motor 1 is illustrated by switching the linear velocity in each area at a higher speed as it goes toward the outer peripheral area. In this case, the speed difference Vd4 between the inner and outer peripheries can be made smaller than the speed difference Vd3 in FIG. 5, and it is possible to promote a reduction in access time and a reduction in power consumption.

FIG. 7 minimizes the speed difference between the inner and outer circumferences, and the area is finely divided by using certain addresses n31 to n36 as boundaries. Then, the linear velocities in the respective areas are switched at a higher speed as they approach the outer peripheral area. In this case, the speed difference Vd5 between the inner and outer circumferences can be extremely small.

Although the respective examples have been described above, it is needless to say that the present invention is not limited to the illustrated ones, and various other examples can be considered. In particular, the number of area divisions and the set value of the linear velocity in each area should be set according to the characteristics, circuit configuration, processing capacity, and the like of each playback device. In addition, as shown in FIG. 2, the example in which the linear velocity is switched for each area using the table data is shown. However, it is of course possible to perform the linear velocity switching according to the area by the arithmetic processing using the detected address. It is.

[0038]

As described above, the reproduction apparatus of the present invention divides and sets the area on the disk in the radial direction, determines the area where the reproduction scan is being performed, and determines the reproduction line according to the determined area. Speed switching control is performed so that the difference between the disk rotation speeds at the inner and outer circumferences of the disk is smaller than the rotation speed difference at the inner and outer circumferences when the linear speed is not switched over the entire area on the disk. ing. By reducing the difference between the rotation speeds on the inner and outer sides of the disk in this manner, the rotation speed settling time after access and the acceleration / deceleration amount of the rotation speed can be reduced, thereby speeding up the access operation and reducing power consumption. This has the effect of realizing the reduction of the amount.

[Brief description of the drawings]

FIG. 1 is a block diagram of a playback device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a data table of areas and linear velocities in the playback device according to the embodiment;

FIG. 3 is an explanatory diagram of a relationship between a region and a rotation speed in the playback device according to the embodiment;

FIG. 4 is an explanatory diagram of a modified example of the linear velocity switching method in the reproducing device of the embodiment.

FIG. 5 is an explanatory diagram of a modification of the linear velocity switching method in the playback device of the embodiment.

FIG. 6 is an explanatory diagram of a modification of the linear velocity switching method in the playback device of the embodiment.

FIG. 7 is an explanatory diagram of a modification of the linear velocity switching method in the playback device of the embodiment.

FIG. 8 is an explanatory diagram of a relationship between a region and a rotation speed in a conventional reproducing apparatus.

[Explanation of symbols]

1 spindle motor, 2 optical head, 5 RF amplifier, 7 servo processor, 9 decoder, 11 PL
L circuit, 13 reference frequency setting circuit, 14 speed controller, 15 spindle motor driver, 16 system controller, 17 memory

Claims (2)

[Claims] 1. A reproducing apparatus for a disk-shaped recording medium on which information is recorded by a constant linear velocity method, wherein a region on a disk is divided and set in a radial direction.
An area discriminating means capable of discriminating an area where the reproduction scanning is being performed; and a reproduction control means for controlling switching of a reproducing linear velocity in accordance with the area determined by the area discriminating means. Playback device. 2. The reproduction control means according to claim 1, wherein the difference between the rotational speed of the disk at the time of scanning the innermost periphery of the disk and the rotational speed of the disk at the time of scanning the outermost periphery of the disk switches the linear velocity in the entire area on the disk. 2. The reproducing apparatus according to claim 1, wherein the reproducing linear velocity is switch-controlled so as to be smaller than the velocity difference in the case where there is no reproduction.