JPH11134776A - Disk reproducing device and data reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a disk rotation standby time and to rapidly start data read-out processing by temporarily accelerating a rotational speed of a disk like recording medium only for the time from an end place of seek operation until arriving at a start position (transfer request start position) of a read-out section. SOLUTION: When a read command is issued, the seek operation is started making a top of a transfer request sector of a spiral track TK, that is, the transfer request start position TGS as a target. When a seek landing point SE is defined to be nearly one revolution or below this side from the transfer request start positron TGS, an angle of a read-out standby W becomes θW, and since it is the angle θN or above, a spindle motor is accelerated temporarily. Then, when it becomes this side by the angle θN from the transfer request start position TGS, the spindle motor is decelerated to be made regular rotation, and the read operation RD of the data is performed until a transfer request end position TGE. Thus, the time of the read-out standby W is shortened, and a whole data transfer time is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk reproducing apparatus capable of performing a reproducing operation for a disk-shaped recording medium.

[0002]

2. Description of the Related Art CD (Compact Disc) type discs as optical disc recording media and DVD (Digital Versatile Disc / Digital) suitable for multimedia applications.
Discs called VideoDisc) have been developed. In a reproducing apparatus corresponding to these optical discs, data is read by irradiating a track on the disc with laser light and detecting the reflected light.

Tracks TK on a disk are formed, for example, in a spiral shape from the inner circumference to the outer circumference of the disk, as schematically shown in FIG. When the disk is rotated, laser light from the reproducing device is irradiated along the spiral track, and data is read.

[0004]

By the way, in a reproducing apparatus for performing a disk reproducing operation in response to a read command (data transfer request) from a host computer and transmitting the reproduced data to the host computer, for example, It is required to perform data transfer promptly. The read command includes data as a normal read command, a start position as a transfer request data section, and a data length from the start position. That is, the host computer specifies a playback command and a section to be played back.

As an operation of the reproducing apparatus when such a read command is generated, first, a seek operation of the optical head is executed in order to read a requested data section together with the read command. That is, this is a seek operation for reading data from a start position of a data section requested to be transferred by a read command (hereinafter, referred to as a transfer request start position). After the seek is completed, data reading is started from the time when the transfer request start position is reached, and the reading operation is performed up to the end position of the data section requested to be transferred by the read command (hereinafter, referred to as a transfer request end position). As described above, data is read from the transfer request start position to the transfer request end position, necessary decoding processing and error correction processing are performed, and the requested data is transferred to the host computer.

One of the causes of such an operation delay is a standby time from the end of the seek operation to the point where the transfer request starts. FIG. 8 illustrates the processing delay due to the standby time. FIG. 8 shows a part of a spiral track TK on the disk, and it is assumed that data reading from the transfer request start position TGS to the transfer request end position TGE is requested as shown in FIG. The seek operation of the optical head is performed, for example, from the transfer request start position TGS to the track 1.
The target position is set to the range before the orbit. Now, the position of the spot of the laser beam at the time when the seek operation has been completed (hereinafter referred to as a seek landing point) is the transfer request start position TGS.
It is assumed that the position is indicated by SE in FIG.

In this case, as shown by the broken line, the read standby W is maintained until the spot reaches the transfer request start position TGS.
Becomes In the case of this example, the rotation time for about ／ of the disk becomes the standby time. When the spot reaches the transfer request start position TGS, the read operation RD up to the transfer request end position TGE is executed as shown by the thick line. In other words, in the case of this example, the time required for the disk to rotate about 3/4 turns is wasted time, and the rotation wait (latency)
The data transfer to the host computer is delayed by the time. Such a rotation wait is the time required for the disk to make a rotation of less than about one round at the maximum, depending on the positional relationship between the seek landing point and the transfer request start position TGS.

[0008]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a disk reproducing apparatus for performing a reproducing operation on a disk-shaped recording medium having tracks formed in a spiral shape. An object of the present invention is to eliminate a delay in a reproducing operation due to a waiting time.

For this purpose, the control means of the reproducing apparatus causes the read position control means to execute a seek operation of the data read means with a target of the start position of the read section in response to a data request in which the read section is designated. The spindle means temporarily increases the rotation speed of the disk-shaped recording medium until the read position of the data read means reaches the start position of the read section (transfer request start position) from the end point of the seek operation. I do. That is, the rotation waiting time is reduced by temporarily increasing the disk rotation speed during the rotation waiting period. Of course, after the end of the rotation waiting, that is, when the transfer request start position is reached, the reading operation is started at the normal rotation speed. After the start, deceleration is performed at a predetermined timing.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a disk reproducing apparatus using an optical disk as a recording medium will be described as an embodiment of the present invention. The optical disc loaded in the disc reproducing apparatus of these examples is, for example, a CD-DA (Compact Disc Digital).
AUDIO), CD-type discs such as CD-ROM,
DVD (DIGITAL VERSATILE DISC / DIGITAL VIDEO DIS
A disk called C) is conceivable. Of course, the present invention can be applied to a disc reproducing apparatus corresponding to other types of optical discs.

FIG. 1 is a block diagram of a main part of the disk reproducing apparatus of the present embodiment. The disc 90 is loaded on the turntable 7 and is driven by the spindle motor 1 at a constant linear velocity (CLV) or a constant angular velocity (CA) during a reproducing operation.
V). The pickup 1 reads data recorded on the disk 90 in the form of embossed pits or phase change pits. In the pickup 1, a laser diode 4 serving as a laser light source, a photodetector 5 for detecting reflected light, an objective lens 2 serving as an output end of the laser light, and a laser beam are irradiated on the disk recording surface via the objective lens 2. Further, an optical system for guiding the reflected light to the photodetector 5 is formed. The objective lens 2 is held by a biaxial mechanism 3 so as to be movable in a tracking direction and a focus direction. The entire pickup 1 can be moved in the disk radial direction by a thread mechanism 8.

The information on the reflected light from the disk 90 is detected by the photodetector 5, converted into an electric signal corresponding to the amount of received light, and supplied to the RF amplifier 9. The RF amplifier 9 includes a current-voltage conversion circuit, a matrix operation / amplification circuit, and the like corresponding to output currents from a plurality of light receiving elements as the photodetector 5, and generates necessary signals by matrix operation processing. For example, it generates an RF signal as reproduction data, a focus error signal FE for servo control, a tracking error signal TE, and the like. The reproduction RF signal output from the RF amplifier 9 is supplied to a binarization circuit 11, and the focus error signal FE and the tracking error signal TE are supplied to a servo processor 14.

The reproduced RF signal obtained by the RF amplifier 9 is 2
By being binarized by the value conversion circuit 11, it is converted into a so-called EFM signal (8-14 modulated signal; in the case of CD) or an EFM + signal (8-16 modulated signal; in the case of DVD), and supplied to the decoder 12. The decoder 12 performs EFM demodulation, error correction processing, and the like.
The information read from the disk 90 is reproduced by performing OM decoding, MPEG decoding, and the like.

The decoder 12 accumulates the data subjected to the EFM demodulation in a data buffer 20 as a memory unit, and performs error correction processing and the like on the data buffer 20. That is, as data to be reproduced and output,
While the data read from the data buffer is accumulated in the data buffer 20, necessary processing such as error correction processing is performed to form a predetermined data stream.

The interface unit 13 is connected to an external host computer and communicates reproduction data and read commands with the host computer. That is, the reproduced data constructed on the data buffer 20 is output to the host computer via the interface unit 13. A read command and other signals from the host computer are supplied to the system controller 10 via the interface unit 13.

The servo processor 14 detects various focus, tracking, thread, and spindle servo drives based on a focus error signal FE and a tracking error signal TE from the RF amplifier 9 and a spindle error signal SPE from the decoder 12 or the system controller 10. A signal is generated to execute a servo operation. That is, the focus error signal FE and the tracking error signal T
A focus drive signal and a tracking drive signal are generated according to E and supplied to the two-axis driver 16. The two-axis driver 16 drives the focus coil and the tracking coil of the two-axis mechanism 3 in the pickup 1. As a result, a tracking servo loop and a focus servo loop are formed by the pickup 1, the RF amplifier 9, the servo processor 14, the two-axis driver 16, and the two-axis mechanism 3.

The servo processor 14 sends a spindle error signal SP to the spindle motor driver 17.
The spindle drive signal generated according to E is supplied. The spindle motor driver 17 applies, for example, a three-phase drive signal to the spindle motor 6 according to the spindle drive signal, and executes the CLV rotation of the spindle motor 6. Further, the servo processor 14 generates a spindle drive signal in response to a spindle kick / brake control signal from the system controller 10, and causes the spindle motor driver 17 to execute operations such as starting or stopping the spindle motor 6. An FG (frequency generator) 6a is attached to the spindle motor 7, and the FG 6a outputs an FG pulse which is a frequency signal corresponding to the motor rotation speed. The system controller 11 can know the rotation speed and the rotation angle position of the spindle motor 6 (disk 90) by counting the FG pulse.

The servo processor 14 generates a thread drive signal based on, for example, a thread error signal obtained as a low-frequency component of the tracking error signal TE or an access execution control from the system controller 10 and supplies the thread drive signal to the thread driver 15. I do. The thread driver 15 drives the thread mechanism 8 according to a thread drive signal. Although not shown, the thread mechanism 8 has a mechanism including a main shaft for holding the pickup 1, a thread motor, a transmission gear, and the like.
5 drives the sled motor 8 according to the sled drive signal, whereby the required sliding movement of the pickup 1 is performed.

The laser diode 4 in the pickup 1 is driven by a laser driver 18 to emit laser light. The system controller 10 sets the control value of the laser power in the auto power control circuit 19 when executing the reproducing operation on the disc 90, and the auto power control circuit 19 performs the laser output according to the set laser power value. The laser driver 18 is controlled so as to be operated.

When the apparatus is capable of performing a recording operation, a signal modulated according to recording data is applied to the laser driver 18. For example, when recording is performed on a recordable type disc 90, the recording data supplied from the host computer to the interface unit 13 is added with an error correction code by an encoder (not shown),
After processing such as EFM + modulation is performed, the data is supplied to the laser driver 18. Then, the laser driver 18 causes the laser diode 4 to perform a laser emission operation according to the recording data, so that data recording on the disk 90 is performed.

Various operations such as servo, decoding and encoding as described above are controlled by a system controller 10 formed by a microcomputer.
For example, as a series of playback operation control, the system controller 10 issues a command to the servo processor 14 as an operation for reading a requested data section in response to a read command from the host computer, and issues a transfer request by the read command. The seek operation of the pickup 1 targeting the transfer request start position as the data section thus performed is executed. After the seek is completed, the data section from the transfer request start position to the transfer request end position is read, and the decoder 12 and the data buffer 20 perform necessary processing, and the reproduction from the transfer request start position to the transfer request end position is performed. Control is performed to transfer data (requested data) from the interface unit 13 to the host computer.

The processing when a read command is issued from the host computer in such a disk reproducing apparatus will be described with reference to FIGS. FIG. 2 shows a control process of the system controller 10 when a read command is generated, and FIG. 3 schematically shows an operation on a track TK of the disk 90 realized by the control of the system controller 10. is there. FIG. 4 shows the operation of controlling the rotation speed of the spindle motor 6 before the start of the reading operation.

When a read command is generated, the processing of the system controller 10 proceeds to step F101 in FIG. 2, and firstly performs a seek operation with respect to the specified request data range (the leading address and data length to be read) together with the read command. . In this case, the seek target is set at a transfer request start position as a target, and is within a range of one track before the transfer request start position. By setting such a seek target to the servo processor 14 as a seek operation and issuing an instruction, the movement of the pickup 1 by the sled mechanism 8 and the movement of the objective lens 2 by the biaxial mechanism 3
By the track jump, the position of the laser spot is moved to a range one track before the transfer request end position. Upon completion of such a seek operation, the process proceeds from step F102 to F103, and then proceeds to step F103.
At 103, it is determined whether or not to execute a spindle control operation which is a characteristic operation of the present embodiment.

First, in step F103, an angle as a track range from the landing point of the seek operation to the transfer request start position TGS is determined. This angle is a rotation angle range (rotation waiting angle) corresponding to a reading standby period from when the laser spot from the pickup 1 reaches the transfer request start position TGS from the seek landing point. As shown in FIG. 3, the seek landing point SE is, for example, the transfer request start position TG.
Assuming that the point is about one turn before S, the rotation waiting angle becomes θW as shown in the figure. That is, the rotation of the disk 90 by the angle θW causes the laser spot to reach the transfer request start position TGS. The period required for rotation by the angle θW is a rotation waiting period, and is read out as indicated by a broken arrow W. It will wait for operation.

The rotation waiting angle θW differs each time depending on the positional relationship between the seek landing point SE and the transfer request start position TGS. In step F103, the rotation waiting angle θW is set to the angle illustrated in FIG. This is a process for determining whether or not θN or more. In the example of FIG. 3, the angle θN is an angle range from the transfer request start position TGS to about 45 ° before. Note that this angle θN = 4
5 mm is only an example. The rotation waiting angle θW can be calculated, for example, from the address obtained at the seek landing point SE and the address of the transfer request start position TGS.

If the rotation waiting angle θW is equal to or larger than the predetermined angle θN, the process proceeds to step F104, and instructs the servo processor 14 to accelerate the spindle motor 6. Thus, an acceleration drive voltage is applied from the spindle motor driver 17 to the spindle motor 6, and the rotation speed of the spindle motor 6 (disk 90) is accelerated. For example, FIG. 4A shows the rotational speed of the spindle motor 6 and FIG. 4B shows the drive voltage. From the time when the process proceeds to step F104, that is, from the time when the laser spot is at the seek landing point SE, FIG. As shown in FIG. 4B, the drive voltage is raised from the normal voltage VN (that is, the voltage value corresponding to the rotation speed SPN to be controlled in the reading operation) to the voltage value VH, and in response to this, as shown in FIG. As described above, the rotation speed of the spindle motor 6 is changed from the rotation speed SPN to
It is accelerated to a higher rotation speed SPH. The rotation speed SPH may be, for example, the maximum rotation speed of the spindle motor 6 or a rotation speed lower than the maximum rotation speed.

After reaching the rotation speed SPH, the spindle motor 6 rotates while maintaining the rotation speed SPH in accordance with the drive voltage VH.
Monitors the rotational angle position, for example, by counting the pulses from the FG 6a as the process of step F105. Then, it is determined whether or not the spindle motor 6 has reached an angular position to be decelerated. As an example, assuming that a position that is located just before the transfer request start position TGS by the angle θN is set as the deceleration position, the disk rotates approximately 3/4 from the seek landing point SE in FIG. 3 (that is, approximately 3 / (When the FG pulse count for 4 rotations is performed)
The system controller 10 determines that the deceleration position G has been reached, advances the process to step F106, and instructs the servo processor 14 to decelerate the spindle motor 6. For example, at the timing of the deceleration position G, as shown in FIG.
The drive voltage is returned to the normal voltage VN, and accordingly, the rotation speed of the spindle motor 6 is changed from the high rotation speed SPH to the more normal rotation speed SPH as shown in FIG.
Deceleration to N. After the completion of the deceleration, the motor rotates while maintaining the rotation speed SPN according to the drive voltage VN.

After the deceleration processing, the system controller 10
Monitors in step F107 whether the position of the laser spot has reached the transfer request start position TGS. Then, when the transfer request start position TGS is reached, the process proceeds to step F108, and the data read operation RD from the transfer request start position TGS is performed as shown in FIG.
The read data is subjected to decoding, error correction processing, and the like, and is stored in the data buffer 20.
The data is transferred to the host computer via the interface unit 13. The read operation RD is executed up to the transfer request end position TGE, and the data up to the transfer request end position TGE is transferred to the host computer, thereby completing a series of read operations.

By such an operation, the seek landing point SE
Since the spindle motor 6 is temporarily rotated at a high speed during a period during which it is necessary to wait for the disk rotation from the position of the transfer request start position TGS, the disk rotation waiting time is greatly reduced. Thereby, the transfer request start position TGS can be quickly reached after the seek, and the data read operation and the data transfer to the host computer can be quickly realized.

Incidentally, the case where a negative result is obtained in step F103 means that the seek landing point SE is quite close to the transfer request start position TGS, that is, when the disk rotation waiting period is short, as can be seen from FIG. is there. In other words, this is a case where there is no room to execute acceleration / deceleration of the spindle motor 6 or even if such an effect is not obtained. Therefore, in such a case, the process proceeds to step F107 without performing acceleration / deceleration of the spindle motor 6, waits for arrival at the transfer request start position TGS, and performs data reading and transfer processing when the transfer request start position TGS is reached. become.

The rotation angle position can be monitored by means other than counting the FG pulse. For example, when the number of edges of the output of the RF signal binarization circuit 11 is counted, or when the PLL circuit (reproduction clock generation unit) in the decoder 12 can be locked even in the high-speed rotation state, the reproduction clock is counted. , The rotational angle position can be determined. The monitoring of the rotational angle position is for obtaining the timing for decelerating the spindle motor 6 as described above, and various methods of setting the deceleration timing are conceivable. Further, the deceleration timing should be appropriately determined according to the performance, responsiveness of the spindle motor 6, a set value as the rotation speed VH, and the like.

For example, depending on the responsiveness of the spindle motor 6, the relationship between the drive voltage and the change in the rotational speed has a difference as shown in FIGS. The example shown in FIG. 4 is a case of a spindle motor having a relatively high response to the drive voltage. As can be seen from the figure, the rotation speed quickly follows by changing the drive voltage between the voltage VN and the voltage VH. However, the example in FIG. 5 is a case of a spindle motor having relatively poor response, and it takes a long time to reach the rotation speed SPH even if the drive voltage is switched from the voltage VN to the voltage VH as shown in the figure. . Further, even if the drive voltage is switched from the voltage VH to the voltage VN, it takes time to return to the normal rotation speed SPN. For example, in the case of a spindle motor whose response is set gently in this way, the deceleration timing must be relatively fast in order to set the normal speed SPN at the transfer request start position TGS.

For example, from such circumstances, various settings of the acceleration / deceleration timing in the period from the seek landing point SE to the transfer request start position TGS can be considered. Of course, the rotation waiting angle θW between the seek landing point SE and the transfer request start position TGS also changes for each reproduction operation.
The optimum timing of acceleration / deceleration differs depending on the rotation waiting angle θW. One of the methods of setting the deceleration timing may be a position where the angle up to the transfer request start position TGS reaches a certain specific angle, as in the above-described example, or an intermediate angle of the rotation waiting angle θW. The position may be set in accordance with the rotation waiting angle θW determined at the time of seek landing.

For example, FIG. 6A shows an example in which a spindle motor 6 whose response is set relatively gently as shown in FIG. 5 is employed. In this example, the rotation waiting angle θW
Is set as the deceleration position G so that the rotation speed returns to the normal rotation speed SPN when the transfer request start position TGS is reached. In FIG. 6B, for example, the intermediate angle position in the angle range from the seek landing point SE to a point in front of the transfer request start position TG by a predetermined angle (for example, θN) is set as the deceleration position G, and the transfer is performed. Request start position TG
The rotation speed is returned to the normal rotation speed SPN at the point when the vehicle reaches a point before the predetermined angle.

FIG. 6C shows an example in which the spindle motor 6 whose response is set relatively quickly is employed. In this example, the point before the transfer request start position TG by a predetermined angle is decelerated. G starts deceleration and returns to the normal rotation speed SPN when the transfer request start position TG is reached. In the example of FIG. 6D, deceleration is started at a point that is a predetermined angle before the transfer request start position TG as the deceleration position G, and returns to the normal rotation speed SPN before reaching the transfer request start position TG. That's what we do. Setting the predetermined angle to θN corresponds to the example of FIG. As described above, various setting of the deceleration timing can be considered, and a suitable method may be adopted in consideration of the performance of the spindle motor 6 and the like.

Although the embodiment has been described above, various modifications of the configuration and operation of the reproducing apparatus are conceivable as the present invention. Regardless of the operation, the spindle high-speed rotation may be performed during the period of waiting for the disk rotation. In addition, although the description has been given of the example of the disk in which the track progresses spirally from the inner circumference to the outer circumference, the present invention is also applicable to a playback apparatus corresponding to a disk in which the track progresses spirally (data recording and playback direction) from the outer circumference to the inner circumference. Is applicable.

[0037]

As described above, according to the present invention, during the period from the end point of the seek operation to the start position of the read section (transfer request start position), that is, during the disk rotation wait period, the disk shape is temporarily stopped. Since the rotation speed of the recording medium is increased, the disk rotation waiting period is shortened accordingly, and the data reading process can be started quickly. This has the effect that data reproduction and output (for example, data transfer to the host computer) can be performed very quickly.

Further, after increasing the rotation speed of the disk-shaped recording medium during the rotation waiting period, the rotation speed is reduced at a required timing so that the disk rotation speed at the transfer request start position can be adjusted to an appropriate speed ( (Predetermined speed for the read operation), so that the read operation is not adversely affected. Furthermore, when the section from the end point of the seek operation to the transfer request start position is a section within a predetermined angle on the disk-shaped recording medium, that is, the disk rotation waiting period is originally a minute period. In this case, the most appropriate processing is executed by not increasing the rotation speed of the disk-shaped recording medium.

[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 a flowchart of a process when a read command is generated according to the embodiment;

FIG. 3 is an explanatory diagram of a read operation according to the embodiment;

FIG. 4 is an explanatory diagram of a rotation speed increasing operation of the embodiment.

FIG. 5 is an explanatory diagram of another rotation speed increasing operation of the embodiment.

FIG. 6 is an explanatory diagram of various rotation speed increasing operations that can be adopted in the embodiment.

FIG. 7 is an explanatory diagram of a spiral track of a disk.

FIG. 8 is an explanatory diagram of a conventional read operation.

[Explanation of symbols]

1 pickup, 2 objective lens, 2 biaxial mechanism, 4
Laser diode, 5 photo detector, 6 spindle motor, 6a FG, 8 thread mechanism, 9 R
F amplifier, 10 system controller, 13 interface unit, 14 servo processor, 20 data buffer, 90 disk, TGS transfer request start position, TGE transfer request end position, SE seek landing point,
W read standby, RD read operation

Claims (4)

[Claims] 1. A disk reproducing apparatus for performing a reproducing operation on a disk-shaped recording medium having tracks formed in a spiral shape, comprising: a spindle means for rotatingly driving the disk-shaped recording medium; Data reading means for performing reading, reading position control means for controlling a reading position of the data reading means with respect to the track, and reading in response to a data request in which a reading section is designated, targeting a start position of the reading section. While causing the position control means to execute the seek operation of the data read means, the spindle means is temporarily operated until the read position of the data read means reaches the start position of the read section from the end point of the seek operation. Control means for increasing the rotation speed of the disk-shaped recording medium; and Disk reproducing apparatus for. 2. The control means, wherein the spindle means increases the rotation speed of the disk-shaped recording medium by the spindle means, and then reduces the rotation speed of the disk-shaped recording medium by the spindle means at a required timing. When the read position of the data read means reaches the start position of the read section,
2. The disk reproducing apparatus according to claim 1, wherein the rotational speed of the disk-shaped recording medium is set to a predetermined speed for a reading operation. 3. The method according to claim 1, wherein the section from the end point of the seek operation to the start position of the reading section is a section within a predetermined angle on a disk-shaped recording medium. 2. The disk reproducing apparatus according to claim 1, wherein the rotation speed of the disk-shaped recording medium is not increased by the means. 4. A data reproducing method for a disk-shaped recording medium having tracks formed in a spiral shape, wherein a seek operation is performed with a target of a start position of the read section in response to a data request in which a read section is specified. After temporarily increasing the rotation speed of the disk-shaped recording medium during a read standby period from the end point of the seek operation to the start position of the read section, the speed is reduced to a predetermined speed for the read operation, A data reproducing method, wherein a data read operation is performed from a point in time when a read section start position is reached.