JP2008108401A - Disk drive apparatus and seeking method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the time required for seeking operation accompanied by an interlayer jump and horizontal direction movement in a disk drive apparatus provided with a plurality of optical heads. <P>SOLUTION: When executing seeking to different radial positions of different recording layers from a recording layer currently under tracing, the movement in the disk radial direction is first executed with respect to each optical head and thereafter, the interlayer jump is executed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a disk drive device and a seek method for a disk recording medium such as an optical disk having a plurality of recording layers.

Japanese Patent No. 3781305 JP 2004-095176 A JP 2006-012413 A JP 2006-114168 A JP 2006-114169 A

An optical disc is known as an optical recording medium capable of recording / reproducing digital data. In recent years, an optical disc having two or more recording layers has been developed in order to increase the capacity of the optical disc.
FIG. 5 schematically shows a part of the disk drive device. First, an “interlayer jump” operation for moving a recording layer to be read or written of information by the optical head will be described with reference to FIG. To do.
The optical disk 90 has a substrate 94, two recording layers (first layer 91 and second layer 92), and a cover layer 93. In the figure, one optical head 51 (OP: Optical Pickup) is mounted. A disc recording / reproducing system having one optical head is hereinafter referred to as a “1OP system”.

In the optical head 51, the objective lens 53 can be moved in the tracking direction and the focus direction by a biaxial actuator 52.
The optical head 51 is movable in the disk radial direction along a thread shaft 55 in the thread mechanism.
The positional relationship between the two recording layers 91 and 92 in the optical disc 90 is the first layer 91 and the second layer 92 in order from the layer farthest from the cover layer 93 side where the laser beam 54 is incident from the optical head 51. ing.
When reading from or writing to the first layer 91, the objective lens 53 in the optical head 51 is driven in a direction approaching the cover layer 93 of the optical disc 90 so that the laser light 54 is in focus with respect to the first layer 91. To.
When reading / writing the second layer 92, the objective lens 53 in the optical head 51 is driven in a direction away from the cover layer 93 of the optical disc 90, and the laser light 54 is in focus with respect to the second layer 92. Like that.
In this way, driving the biaxial actuator 52 to switch the recording layer on which the laser beam 54 is focused and moving the objective lens 53 up and down is called interlayer jump. Techniques relating to the operation as described above are disclosed in Patent Documents 1, 2, and 3.
In FIG. 5, the description is made using a two-layer disc having two recording layers, but an interlayer jump operation is similarly performed for an optical disc having three or more recording layers.

  By the way, as a mechanism for almost doubling the data transfer speed at the time of recording / reproducing, recording / reproducing having two optical heads 51 mounted so that the laser beam 54 is irradiated to two places on the recording layer of the optical disc 90. A system (hereinafter referred to as “2OP system”) can also be considered.

FIG. 6 schematically shows the head structure of the 2OP system.
6A shows a state where the optical disk 90 is mounted on the spindle motor 56 as viewed from the side, and FIG. 6B shows a state where the optical disk 90 is seen through from above.
As shown in this figure, two optical heads (optical heads 51-1 and 51-2) are mounted on an optical disk 90 so that laser light 54 is irradiated at two locations.
The optical heads 51-1 and 51-2 are arranged on the right side and the left side of the drawing with the spindle motor 56 interposed therebetween. The optical heads 51-1 and 51-2 are movable along the thread shaft 55 from the innermost circumference side to the outermost circumference side in the disk radial direction.
By mounting the two optical heads 51-1 and 51-2 in this way, the data transfer speed between the optical disk 90 and the outside of the disk drive device is almost doubled compared to the case of the 1OP system. Is possible.

  Assuming such a 2OP system, there is a problem with the seek time when seeking with an interlayer jump and radial movement. In order to understand this problem, the operation in the 1OP system will be described below. Including the explanation in order.

First, the basic seek operation will be described.
For example, when the optical disk is a single layer (one recording layer), or even if the optical disk has a plurality of recording layers and the target address is in the same recording layer as the current address, the optical head 51 is moved in the disk radial direction (hereinafter referred to as the optical disk 51) For convenience, seek is performed by moving the disk radial direction to the horizontal direction).
Here, first, a seek without such an interlayer jump is considered.

Normally, when starting a seek operation, a system (for example, a controller in a disk drive device) knows an address on a track currently traced by the optical head 51 (hereinafter referred to as “current address”). There is a need. “Trace” refers to a state in which the optical head 51 scans a recording track on the optical disk 90 with the laser beam 54 to reproduce or record information.
For example, when a seek is executed in response to a request from a host device or a user operation, the number of tracks between an address as a seek destination (hereinafter referred to as a “target address”) and a current address is calculated. The optical head 51 is moved along the thread shaft 55 by the number of tracks (the number of jump tracks).
Normally, it is possible to move to the vicinity of the target address only by this operation.

Here, when the optical disk 90 is rotated at a constant linear velocity (CLV), the disk rotation speed by the spindle motor 56 is slower as the trace position goes to the outer periphery, and conversely, it becomes faster as it goes to the inner periphery. Controlled.
Therefore, when moving to the outer peripheral side by seeking, the rotational speed of the spindle motor 56 needs to be lowered, and when moving to the inner peripheral side by seeking, the rotational speed of the spindle motor 56 needs to be increased. .

As described above, the optical head 51 is moved by the number of jump tracks between the current address and the target address. When the optical head 51 reaches the vicinity of the target address, the address is read at that position to determine whether the target address is reached. To check.
However, at that time, if the change in the rotational speed of the spindle motor 56 due to the horizontal movement of the optical head 51 is incomplete and the linear velocity is not set to a predetermined value, the address cannot be read out. For this reason, even when the horizontal movement of the calculated number of jump tracks is completed, it is necessary to wait until the linear velocity is locked to a predetermined value (a CLV rotation servo state).
When the linear velocity is locked to a predetermined value, the address can be read. As a result, when it is confirmed that the current position is the target address, the seek operation is terminated.

Next, a seek operation without an interlayer jump as described above will be applied to the 2OP system.
When a 2OP system is considered in a CLV system, the concept of “synchronous seek” is required.

FIG. 7 shows the positional relationship between the optical heads 51-1 and 51-2 in the CLV 2OP system. As described above, the rotation speed of the spindle motor 56 is controlled such that a predetermined linear velocity is obtained at the disk radial position where the optical heads 51-1 and 51-2 are to be recorded and reproduced on the optical disk 90.
Then, the optical heads 51-1 and 51-2 must always have the same distance from the center of the spindle motor 56 (that is, the disk radial position).

That is, as shown in FIG. 7, if the distances from the center of the spindle motor 56 to the optical head 51-1 are d1 and d2, the distances from the center of the spindle motor 56 to the optical head 51-2 are d1 ± α and d2 ± α. It is necessary to become. Α is a predetermined value and is determined by the tracking range of a PLL (Phase Locked Loop) that generates a reproduction clock in the reproduction processing system.
If the positional relationship between the optical heads 51-1 and 51-2 is viewed as a distance from the center of the spindle motor 56, the optical head 51-1 is not within the ± α difference range. , 51-2, the linear velocity of the optical disc 90 deviates from a predetermined value. For this reason, the optical head that has deviated from the linear velocity cannot read the address on the recording track on the optical disc 90 and cannot read / write to the optical disc 90 at the same time.
Considering this, for example, when the optical head 51-1 performs a seek operation, the optical head 51-2 also performs a seek operation in synchronization, and both optical heads 51-1 and 51-2 after the seek operation. Therefore, the distance from the center of the spindle motor 56 needs to be substantially the same.
In this way, the operation of seeking both optical heads 51-1 and 51-2 at the same time during seek is called “synchronous seek”.

In the 2OP system, as this synchronous seek, a seek operation and a required time when no interlayer jump is involved will be described with reference to FIG.
In FIG. 8, the operations of the optical head 51-1 and the optical head 51-2 at the time of seek and the rotational speed control operation of the spindle motor 56 are shown on the time axis.

First, if a seek request for the optical head 51-1 is generated at time t81, the optical head 51-1 that was being traced starts horizontal movement from time t81.
However, the rotation speed change of the spindle motor 56 is not started at this time t81. This is because the optical head 51-2 is still tracing at time t81, and if the rotational speed of the spindle motor 56 is changed at time t81, the linear velocity is shifted for the optical head 51-2 being traced. This is because it becomes impossible to read the address immediately before the start of seek.

Because of the necessity of performing a synchronous seek, a seek request is generated for the optical head 51-2 after a seek request for the optical head 51-1 is generated. For example, when a seek request for the optical head 51-2 occurs at time t82, the optical head 51-2 also starts horizontal movement as a seek.
The rotation speed changing operation of the spindle motor 56 is started only at this time t82. That is, the speed lock state by the CLV rotation servo is once released, and an operation is started in which the rotation speed of the spindle motor 56 is changed toward the CLV speed at the target address position of the seek destination. That is, the retraction of the rotational speed with respect to the seek CLV speed is performed.

In FIG. 8, a period from time t81 to time t82 is expressed as a command waiting time TC. This command waiting time TC occurs for the following reason.
The seek operation is normally controlled by a CPU that functions as a control unit of the disk drive device. If the CPU is interrupted at the moment when the optical head 51-1 reads the track address, the CPU transmits a seek request to the optical head 51-1. Similarly, when the CPU is interrupted at the moment when the optical head 51-2 reads the address of the track, the CPU transmits a seek request to the optical head 51-2, so an asynchronous time difference is inevitably generated. Even if the CPU is interrupted at the same time, the CPU cannot execute two processes at the same time. Therefore, since the CPU takes a procedure of issuing a seek request for the other optical head 51-2 after issuing a seek request for the one optical head 51-1, a time difference occurs. .

It is assumed that the optical head 51-1 moves horizontally and reaches the vicinity of the target address at time t83. Further, it is assumed that the optical head 51-2 has moved horizontally and has reached the vicinity of the target address at time t84.
However, at these time points, the drawing of the rotational speed of the spindle motor 56 has been completed. Since the CLV speed has not been set, the address reading by the optical heads 51-1 and 51-2 cannot be performed. As a result, the spindle lock is awaited.
Thereafter, when the rotation speed of the spindle motor 56 is re-locked to the CLV speed at time t85, the optical heads 51-1 and 51-2 can read the address at that time. If the read address is the target address, the seek is completed. For example, after time t86, the information can be reproduced or recorded as a trace.

  In general, since the time required for pulling in the rotational speed of the spindle motor 56 is longer than the horizontal movement time of the optical heads 51-1 and 51-2, the optical heads 51-1 and 51-2 are of the example shown in FIG. Thus, in many cases, the rotation speed pull-in is waited after the horizontal movement is completed.

Next, with reference to FIG. 9, the case of the 1OP system will be described first with respect to the seek operation involving interlayer jump and horizontal movement.
9 shows, for example, when tracing is performed at a certain radial position of the second layer 92 as shown on the left side of FIG. 5, different radial positions on the first layer 91 as shown on the right side of FIG. This is the operation when seeking as a target address.

Assume that a seek request for the optical head 51 is generated at time t91. Then, the optical head 51 starts an interlayer jump.
Assume that the interlayer jump is completed at time t92. At this time, address reading is performed on the recording layer after the jump. Further, the speed lock of the spindle motor 56 is continued for address reading at this time.
The address read immediately after the interlayer jump is a “starting address” for horizontal movement. This corresponds to the “current address” described in the seek without the interlayer jump. In this case, the number of jump tracks from the starting address to the target address is calculated and the horizontal movement is performed.

When grasping of the starting address in the recording layer after the interlayer jump is completed at time t93, the horizontal movement of the optical head 51 is started. Further, since the speed lock of the spindle motor 56 may be released thereby, the retraction of the rotational speed of the spindle motor 56 is started.
When the horizontal movement of the optical head 51 is completed at time t94, the CLV speed lock of the spindle motor 56 is waited. When the speed re-retraction of the spindle motor 56 is completed at time t95, the address is confirmed. If the read address is the target address, seek is completed, and for example, tracing as playback or recording is started after time t96.

  Considering the execution of such a seek operation involving an interlayer jump and horizontal movement in the 2OP system, there arises a disadvantage that does not occur in the case of the 1OP system. That is, in the case of the 2OP system, unlike the case of the 1OP system, a time lag occurs between the operations of the two optical heads. As a result, the seek time of the entire system is increased.

With reference to FIG. 10, in the 2OP system, an operation of performing a seek involving an interlayer jump and horizontal movement and a cause of an increase in the seek time of the entire system will be described.
If a seek request for each of the optical head 51-1 and the optical head 51-2 occurs at time t101 and time t102, the optical heads 51-1 and 51-2 start an interlayer jump, respectively. In FIG. 10, the period from time t101 to time t102 is the command waiting time TC.
Assume that the optical head 51-1 completes the interlayer jump at time t103, and the optical head 51-2 completes the interlayer jump at time t105.
The optical head 51-1 reads the address from the time t103 when the interlayer jump is completed, and confirms the starting address. The optical head 51-1 starts to move horizontally from the time point t104 when the starting point address is grasped.
Further, the optical head 51-2 performs address reading from time t105 when the interlayer jump is completed, and confirms the starting address. The optical head 51-2 starts to move horizontally from the time point t106 when the starting point address is grasped.

For the spindle motor 56, the speed lock is released in accordance with the later of the optical heads 51-1 and 51-2 whose movement in the horizontal direction is slower. This is because both the optical heads 51-1 and 51-2 can normally perform address reading.
In the case of the example of FIG. 10, the start address of the optical head 51-2 is grasped, and the speed lock of the spindle motor 56 is released and the speed re-retraction is started at the time t106 when the horizontal movement is started. It will be.

When the horizontal movement of the optical head 51-1 is completed at time t107, the spindle motor 56 waits for CLV speed lock.
When the horizontal movement of the optical head 51-2 is completed at time t108, the spindle motor 56 waits for the CLV speed lock.
Then, when the speed retraction of the spindle motor 56 is completed at the time t109, the optical heads 51-1 and 51-2 each read an address. If the read address is the target address, the seek is completed. For example, after time t110, tracing as reproduction or recording by both the optical heads 51-1 and 51-2 is started.

As can be seen from FIG. 10, in the case of the 2OP system, the two optical heads 51-1 and 51-2 must enter the speed change operation of the spindle motor 56 only after grasping the starting point address after the interlayer jump. I can't.
Therefore, even if one of the optical heads 51-1 and 51-2 can grasp the starting address at an early stage, if the current address grasp of the other optical head is delayed, the later optical head At the same time, the start timing of the speed changing operation of the spindle motor 56 is delayed.
Therefore, for example, when one of the optical heads 51 cannot readily grasp the starting address for some reason such as an instantaneous impact, the seek time (time as time points t101 to t110) of the entire system is extended. Will end up.
FIG. 10 shows the case where the optical head 51-2 is slower in grasping the address. However, depending on the variation in the interlayer jump time and the time required for grasping the address after the interlayer jump, the interlayer jump first occurs. In some cases, the optical head 51-1 that has started the recording of the address is delayed.

That is, in the case of performing the inter-layer jump and the horizontal seek with the horizontal movement in the 2OP system, the grasping of the starting address after each inter-layer jump by the optical heads 51-1 and 51-2 is remarkably as a whole as compared with the case of the 1 OP system. There is a problem that the seek time is affected and the seek time tends to be long. Naturally, a long seek time affects system performance.
Therefore, the present invention has an object to eliminate such a long seek time due to the necessity of grasping the starting point address when performing a synchronous seek accompanied by an interlayer jump and horizontal movement in a 2OP system.

The disk drive device of the present invention is a disk drive device that records or reproduces data on a disk recording medium having a plurality of recording layers, each of which has a plurality of heads that read or write information from or to the plurality of recording layers. And a reproduction processing unit that reproduces information read by the plurality of head units, and the plurality of head units when the seek operation involving both interlayer movement and disk radial movement is performed. And a control unit that performs control to complete the seek operation by moving the layers between the heads in the disk radial direction.
In addition, the control unit causes the interlayer movement to be performed without performing the position confirmation operation of the head unit after moving each of the head units in the disk radial direction.

  The seek method of the present invention is a disk drive device that performs recording or reproduction on a disk recording medium having a plurality of recording layers, each of which reads or writes information to or from a plurality of recording layers in the disk recording medium. A seek method for a disk drive device that performs recording or reproduction with respect to the disk recording medium, and performs a seek operation involving both interlayer movement and disk radial movement on the plurality of head parts. In this case, after each of the plurality of head portions is moved in the disk radial direction, the seek operation is completed by executing interlayer movement.

According to the present invention, at the time of the synchronous seek accompanied by the interlayer jump and the horizontal movement, first, the plurality of head sections each move in the disk radial direction (horizontal movement). Since the address is naturally read during the trace immediately before starting the seek, the "current address" is obtained at the start of the seek, and given the target address, the number of jump tracks when moving in the horizontal direction is It can be calculated.
By moving in the horizontal direction, it is possible to reach almost the same radial position as the target address in the target recording layer on the current recording layer.
Therefore, when the horizontal movement is completed, the target address can be almost reached by performing an interlayer jump. Therefore, when the interlayer jump is completed, address reading is performed to check whether or not the target address has been reached. That is, “starting address grasp” after the interlayer jump is not necessary.
Also, when confirming the target address after the interlayer jump, if there is a slight deviation, it is natural that a fine adjustment seek is performed, but when the horizontal movement is completed, the address confirmation is performed. There is no need to do it.

According to the present invention, when performing a seek operation involving both interlayer movement and disk radial movement for the plurality of head parts, after moving each of the plurality of head parts in the disk radial direction, By executing the interlayer movement and completing the seek operation, the address confirmation operation in the seek operation process can be made efficient. Specifically, it is not necessary to grasp the “starting address” after the interlayer jump and start the horizontal movement.
As a result, there is an effect that the seek time can be shortened when a seek involving an interlayer jump and a horizontal movement is performed by a plurality of head units such as a 2OP system.

A disk drive device according to an embodiment of the present invention will be described below. The disk drive device of this example is a 2OP system including two optical heads.
FIG. 1 shows a block diagram of the disk drive device.
In FIG. 1, two optical heads for reading / writing information from / to the optical disk 90 are provided as shown as an optical head 1a and an optical head 1b, and these are described with reference to FIGS. It is arranged like this.

In relation to the operation of the optical head 1a, a thread mechanism 12a, a thread driver 14a, a biaxial driver 15a, a servo processing unit 16a, a matrix circuit 18a, and a laser control unit 19a are provided.
Similarly, in relation to the operation of the optical head 1b, a thread mechanism 12b, a thread driver 14b, a biaxial driver 15b, a servo processing unit 16b, a matrix circuit 18b, and a laser control unit 19b are provided.
In FIG. 1, two servo processing units 16a and 16b are shown as an example in order to correspond to the optical head 1a and the optical head 1b. However, these servo processing units 16a and 16b are separated as shown in the figure. Alternatively, one servo processing processor may function as the servo processing units 16a and 16b for the optical head 1a and the optical head 1b.

Each of the optical heads 1a and 1b irradiates the optical disk 90 with laser light to read / write information.
In other words, information recorded as embossed pits, dye change pits, and phase change pits on the recording track of the optical disk 90 and information recorded by the wobbling groove are read out. Information includes address information, physical information, management information and the like in addition to main recording data. As address information, if data recording has already been performed, there is an address added to the data, but ADIP (Address in PreGroove) information embedded as wobbling of the groove track on the optical disc 90 is also read. .
When the optical disc 90 is a recordable disc, user data is recorded as a phase change mark or a dye change mark on a track on the optical disc 90 by the optical head 1a and the optical head 1b during data recording.

Although not shown in the drawings, the optical head 1a and the optical head 1b include a laser diode serving as a laser light source, a photodetector for detecting reflected light, an objective lens serving as an output end of the laser light, and laser light passing through the objective lens. Thus, an optical system or the like is formed that irradiates the optical disc recording surface and guides the reflected light to the photodetector.
The objective lens is held by a biaxial actuator so as to be movable in the focus direction and the tracking direction.
The optical head 1a can be moved in the radial direction of the optical disc by the sled mechanism 12a, and the optical head 1b can be moved by the sled mechanism 12b.

Reflected light information from the optical disk 90 is detected by a photodetector in the optical head 1a, converted into an electrical signal corresponding to the amount of received light, and supplied to the matrix circuit 18a. The reflected light information detected by the photodetector in the optical head 1b is supplied to the matrix circuit 18b.
The matrix circuits 18a and 18b include a current-voltage conversion circuit, a matrix calculation / amplification circuit, and the like corresponding to output currents from a plurality of light receiving elements as photodetectors, and generate necessary signals by matrix calculation processing.
For example, a reproduction RF signal corresponding to reproduction data, a focus error signal for servo control, a tracking error signal, and the like are generated.
Further, a push-pull signal (wobble signal) is generated as a signal for detecting information by groove wobbling.
The reproduction RF signals output from the matrix circuits 18a and 18b are supplied to the reproduction processing unit 22, and the push-pull signals are supplied to the wobble processing unit 23, respectively. The focus error signal and tracking error signal output from the matrix circuit 18a are supplied to the servo processing unit 16a, and the focus error signal and tracking error signal output from the matrix circuit 18b are supplied to the servo processing unit 16b.

The optical disk 90 on which information is recorded / reproduced by the optical head 1a and the optical head 1b is loaded on a turntable (not shown) when loaded in a disk drive device, and is fixed by a spindle motor 11 during a recording / reproducing operation. CLV).
The spindle servo circuit 17 performs control to rotate the spindle motor 11 by CLV.
The spindle servo circuit 17 obtains the clock generated by the PLL processing for the wobble signal obtained as the reflected light information about the wobbling groove as the current rotational speed information of the spindle motor 11 and compares it with predetermined CLV reference speed information. As a result, a spindle error signal is generated.
At the time of data reproduction, the reproduction clock generated by the PLL processing in the reproduction processing unit 22 becomes the current rotation speed information of the spindle motor 11. Therefore, the spindle is compared with predetermined CLV reference speed information. An error signal can also be generated.
The spindle servo circuit 17 outputs a spindle drive signal generated in accordance with the spindle error signal, and causes the spindle driver 13 to execute CLV rotation of the spindle motor 11.
The spindle servo circuit 17 generates a spindle drive signal in response to the spindle kick / brake control signal from the system controller 24, and executes operations such as starting, stopping, acceleration, and deceleration of the spindle motor 11.

The servo processing unit 16a is formed by, for example, a DSP (Digital Signal Processor), generates various servo drive signals for focus, tracking, and thread mechanism from the focus error signal and tracking error signal from the matrix circuit 18a, and executes the servo operation. .
That is, the focus drive signal and the tracking drive signal are generated according to the focus error signal and the tracking error signal, and the focus coil and tracking coil of the biaxial actuator in the optical head 1a are driven by the biaxial driver 15a. As a result, a tracking servo loop and a focus servo loop are formed by the optical head 1a, the biaxial driver 15a, the servo processing unit 16a, the matrix circuit 18a, and the biaxial actuator.
The servo processing unit 16a turns off the tracking servo loop in response to a track jump command from the system controller 24 and outputs a jump drive signal, thereby causing the optical head 1a to execute a track jump operation.
Further, the servo processing unit 16a generates a thread drive signal based on a thread error signal obtained as a low frequency component of the tracking error signal, access execution control from the system controller 24, and the like, and drives the thread mechanism 12a by the thread driver 14a. To do. Although not shown, the thread mechanism 12a includes a mechanism including a thread shaft that holds the optical head 1a, a thread motor, a transmission gear, and the like. The sled mechanism 12a drives the sled motor according to a sled drive signal. The slide movement is performed.

The servo processing unit 16b is also formed by a DSP, for example, and generates servo drive signals for focus, tracking, and sled mechanisms from the focus error signal and tracking error signal from the matrix circuit 18b, and executes the servo operation.
That is, a focus drive signal and a tracking drive signal are generated according to the focus error signal and the tracking error signal, and the focus coil and tracking coil of the biaxial actuator in the optical head 1b are driven by the biaxial driver 15b. As a result, a tracking servo loop and a focus servo loop are formed by the optical head 1b, the biaxial driver 15b, the servo processing unit 16b, the matrix circuit 18b, and the biaxial actuator.
The servo processor 16b turns off the tracking servo loop in response to a track jump command from the system controller 24 and outputs a jump drive signal, thereby causing the optical head 1b to perform a track jump operation.
Further, the servo processing unit 16b generates a thread drive signal based on a thread error signal obtained as a low frequency component of the tracking error signal or access execution control from the system controller 24, and drives the thread mechanism 12b by the thread driver 14b. To do. The sled mechanism 12b includes a sled shaft that holds the optical head 1b, a sled motor, a transmission gear, and the like. The sled mechanism 12b drives the sled motor in accordance with a sled drive signal to perform a required slide movement of the optical head 1b. Is called.

The reproduction processing unit 22 binarizes the reproduction RF signal read from the optical disk 90 by the optical heads 1a and 1b and supplied from the matrix circuits 18a and 18b, and decodes the obtained binary data string. Reproduction data is obtained by performing processing, error correction processing, and the like.
First, as binarization processing, for example, PR (Partial Response) equalization processing and Viterbi decoding (maximum likelihood decoding) processing are performed. That is, a binary data string is obtained by a partial response maximum likelihood decoding process (PRML detection method: Partial Response Maximum Likelihood detection method).
Then, the RLL (1, 7) PP modulation method (RLL: Run Length Limited, PP: Parity preserve / Prohibit rmtr (repeated minimum transition runlength)) is applied to the binary data string obtained by using the partial response maximum likelihood detection method. The data recorded on the optical disc 90 is subjected to demodulation processing, deinterleaving, ECC decoding processing for error correction, and the like, and reproduction data from the optical disc 90 is demodulated.
Although not shown, the reproduction processing unit 22 includes an A / D conversion circuit and a PLL circuit that perform A / D conversion of an RF signal as a preceding stage of binarization processing, and converts the reproduction RF signal that is an analog signal into digital data. Convert to The output from the A / D conversion circuit is supplied to the PLL circuit, and a reproduction clock used for the reproduction processing is generated by the phase locked loop. The generated clock is used as a sampling clock for the A / D conversion circuit and used for Viterbi decoding processing and the like.

  Data demodulated as reproduction data by the reproduction processing unit 22 is transferred to the host interface 21 and transferred to the host device 100 based on an instruction from the system controller 24. The host device 100 is, for example, a computer device or an AV (Audio-Visual) system device.

When the optical disc 90 is a recordable disc, the ADIP information is processed during recording / reproduction.
That is, push-pull signals output from the matrix circuits 18a and 18b as signals relating to groove wobbling are supplied to the wobble processing unit 23, and ADIP information is decoded. In this case, a clock synchronized with the push-pull signal is generated, and the push-pull signal is converted into digital data. Then, MSK demodulation and STW demodulation are performed to demodulate a data string constituting the ADIP address. This data string is decoded, and ADIP information such as an address value is demodulated. The demodulated ADIP information is supplied to the system controller 24.
During recording, recording data is transferred from the host device 100, and the recording data is supplied to the recording processing unit 20 via the host interface 21.
The recording processing unit 20 performs error correction code addition (ECC encoding), interleaving, subcode addition, and the like as recording data encoding processing. Further, RLL (1-7) PP modulation is performed on the data subjected to these processes.

The recording data processed by the recording processing unit 20 is subjected to fine adjustment of the optimum recording power or adjustment of the laser drive pulse waveform for the recording layer characteristics, laser beam spot shape, recording linear velocity, etc. as recording compensation processing. The laser drive pulse signal in the state is supplied to the laser controllers 19a and 19b. The laser drive pulse signal waveform is adjusted based on an instruction from the system controller 24.
Then, the laser control unit 19a applies the laser driving pulse signal subjected to the recording compensation process to the laser diode in the optical head 1a to execute the laser emission driving. Similarly, the laser control unit 19b also applies a laser driving pulse signal to the laser diode in the optical head 1b to execute laser emission driving. As a result, a mark corresponding to the recording data is formed on the optical disc 90.
The laser control unit 19a includes a so-called APC circuit (Auto Power Control), and the laser output power is monitored regardless of the temperature or the like while monitoring the laser output power by the output of the laser power monitoring detector provided in the optical head 1a. Control to be constant. The target value of the laser output at the time of recording / reproduction is given from the system controller 24, and control is performed so that the laser output level becomes the target value at the time of recording and reproduction.
Similarly, the laser controller 19b also includes an APC circuit so that the laser output is constant regardless of the temperature or the like while monitoring the laser output power by the output of the laser power monitoring detector provided in the optical head 1b. Control. The target value of the laser output at the time of recording and reproduction is given from the system controller 24, and the laser output level is controlled to be the target value at the time of recording and reproduction.

Various operations of the servo system and the recording / reproducing system as described above are controlled by a system controller 24 formed by a microcomputer.
The system controller 24 executes various processes in accordance with commands from the host device 100 given via the host interface 21.
For example, when a write command (write command) is issued from the host device 100, the system controller 24 first moves the optical heads 1a and 1b to addresses to be written. Then, the recording processing unit 20 causes the encoding process to be executed as described above for data transferred from the host device 100 (for example, video data, audio data, etc.). Recording is executed by the laser controllers 19a and 19b driving the optical heads 1a and 1b to emit light in accordance with the encoded data as described above.

Further, for example, when a read command for requesting transfer of certain data recorded on the optical disc 90 is supplied from the host device 100, the system controller 24 first performs seek operation control for the instructed address. That is, a command is issued to the servo processing unit 16a, and the access operation of the optical head 1a targeting the address specified by the seek command is executed. Similarly, the servo processing unit 16b causes the optical head 1b to perform an access operation.
Thereafter, operation control necessary for transferring the data in the designated data section to the host device 100 is performed. That is, data is read from the optical disc 90, the reproduction processing in the reproduction processing unit 22 is executed, and the requested data is transferred.

Incidentally, although the example of FIG. 1 is a disk drive device connected to the host device 100 (for example, a personal computer), the disk drive device of the present invention may have a form not connected to other devices. In this case, an operation unit and a display unit are provided, and the configuration of the interface part for data input / output is different from that in FIG. That is, it is only necessary that recording and reproduction are performed in accordance with a user operation and a terminal unit for inputting / outputting various data is formed.
Of course, there are various other configuration examples. For example, examples of a recording-only device and a reproduction-only device are also possible.

Here, in the disk drive device in the 2OP system adopting the above configuration, a seek operation accompanied by an interlayer jump and horizontal movement will be described with reference to FIG.
First, it is assumed that the loaded optical disk 90 has a structure in which two recording layers (a first layer 91 and a second layer 92) are formed on a substrate 94. A first layer 91, an intermediate layer 95, a second layer 92, and a cover layer 93 are formed on the substrate.
The disk drive apparatus according to the present embodiment includes two optical heads 1a and 1b. For convenience of illustration, FIG. 2 shows only one of the optical heads 1a.

In the optical head 1 a, the objective lens 3 a can be moved in the tracking direction and the focus direction by the biaxial actuator 2.
Regarding the positional relationship between the two recording layers of the optical disk 90, the first layer 91 and the second layer 92 are arranged in order from the layer farthest from the surface of the optical disk on which the laser beam 4a is incident.
When reading from and writing to the first layer 91, the objective lens 3a is moved in a direction approaching the cover layer 93 of the optical disc 90 so that the laser beam 4a is in focus with respect to the first layer 91.
When reading / writing the second layer 92, the objective lens 3 a is moved in a direction away from the cover layer 93 of the optical disc 90 so that the laser beam 4 a is focused on the second layer 92.

In this example, when performing a jump with an interlayer jump and horizontal movement, the following operation is performed.
First, it is assumed that the optical head 1 is performing tracing (reproduction or recording) on the second layer 92 in the state on the left side of FIG.
In this state, when a certain target address (seek target position in the figure) in the first layer 91 is given and seek is performed, first, the optical head 1a is horizontally placed on the right side of the drawing as illustrated by the sled mechanism 12a. Move.
By this horizontal movement, the optical head 1a is transferred to almost right below the seek target position in the first layer 91. Directly below means a state in which the second layer 92 is at the same radial position as the seek target position.
When the horizontal movement is completed and the optical head 1a is positioned just below the vicinity of the target address in the first layer 91, an interlayer jump is executed next. That is, the laser beam 4 that has been in focus with respect to the second layer 92 until then can be focused with respect to the first layer 91 as the objective lens 3 moves upward in the drawing. As a result, the recording / reproducing position by the laser beam 4a reaches the “seek target position” shown in the figure.

Although only the optical head 1a is shown here, the optical head 1b performs a similar seek operation.
In other words, in this example, when the optical heads 1a and 1b perform the synchronous seek operation involving both the interlayer movement and the disk radial movement, the optical heads 1a and 1b are first moved in the disk radial direction, and then Then, the interlayer movement is executed to complete the seek operation.
In this seek operation process, it is not necessary to grasp the starting address after the interlayer jump, which is required in the operation described in FIG.

First, during the trace immediately before the seek start time, address reading is naturally performed, so the “current address” for horizontal movement is known.
The horizontal movement is performed first, and the “target address” regarding the horizontal movement can be calculated from the target address given as the seek target. That is, the seek target position is a recording layer different from the current recording layer, but the horizontal movement is aimed at the same radial position as the target address as the seek target position in the current recording layer.
As a result, the number of jump tracks executed as horizontal movement can be calculated. Accordingly, the traversing count (counting of the tracking error signal waveform in the servo-off state) is performed to confirm the number of jump tracks, and the optical heads 1a and 1b are moved in the horizontal direction by the thread mechanisms 12a and 12b, thereby obtaining the target address. Horizontal movement to the position directly below can be performed.

After the horizontal movement is completed, an interlayer jump is immediately performed to reach the target address. At this time, the address is confirmed at the target address, and if the address is the target address, the seek is completed. Of course, if the target address is deviated from, the seek for fine adjustment is executed by transfer by a thread mechanism or track jump by a biaxial actuator.
After the interlayer jump as described above, the address reading for confirming the target address is performed to complete the seek, and when the horizontal movement is completed, the optical heads 1a and 1b Since it can be estimated that it is directly underneath, it is not necessary to grasp the address when moving from the horizontal movement to the interlayer jump.
That is, in the operation described with reference to FIG. 10, it is necessary to grasp the starting address after the interlayer jump in the middle of the seek operation of the interlayer jump and the horizontal movement. In this example, the seek operation of the horizontal movement and the interlayer jump is performed. It is not necessary to grasp the address on the way.

Further, the fact that the horizontal movement is performed prior to the interlayer jump and that the address is not required after the horizontal movement means that if both the optical heads 1a and 1b start the horizontal movement, the spindle motor The re-drawing of the number of revolutions of 56 can be started. That is, the retraction of the rotational speed of the spindle motor 56 can be executed in parallel with the period in which the optical heads 1a and 1b complete both the horizontal movement and the interlayer jump.
As a result, the waiting time from when the optical heads 1a and 1b complete the interlayer jump to when the retraction of the rotational speed of the spindle motor 56 is completed can be shortened.

Such a synchronous seek operation of this example will be described along the time series in FIG.
First, at time t31, when a seek request for the optical head 1a is generated, the optical head 1a that has been tracing until then starts moving in the horizontal direction. As described above, this horizontal movement is performed with the target immediately below the target address of the other recording layer that is the seek target position.
The seek operation is also performed for the optical head 1b due to the necessity of the synchronous seek. When a seek request is generated for the optical head 1b at time t32 with a time lag indicated as the command waiting time TC, tracing has been performed until then. The optical head 1b also starts to move in the horizontal direction. This is also performed with the target immediately below the target address of the other recording layer which is the seek target position.

  Here, since the optical heads 1a and 1b are being moved in the horizontal direction after the time point t32, the speed lock of the spindle motor 56 may be released. Therefore, at time t32, the system controller 24 causes the spindle servo circuit 17 to execute the unlocking of the rotational speed lock of the spindle motor 11 and the redrawing of the speed.

If the optical head 1a completes the horizontal movement at time t33, the optical head 1a immediately performs an interlayer jump. Assume that the interlayer jump is completed at time t35.
If the optical head 1b completes the horizontal movement at time t34, the optical head 1b immediately performs an interlayer jump. Assume that the interlayer jump is completed at time t36.
If the optical heads 1a and 1b have completed the interlayer jump, if the retraction of the rotational speed of the spindle motor 56 has not yet been completed, the optical heads 1a and 1b wait for the completion of the retraction of the rotational speed. .
Thereafter, when the retraction of the rotational speed of the spindle motor 56 is completed at time t37 and the spindle servo circuit 17 shifts to the CLV servo lock state, the optical heads 1a and 1b both read the address and reach the target address. Check if it exists.
If the read address is the target address, the seek is completed at that time. If there is a slight deviation, a fine adjustment seek is performed, and the seek is completed when the target address is reached. Then, upon completion of seek, the state shifts to the trace state from the target address.

As described above, in this embodiment, in the 2OP system including the optical heads 1a and 1b, a seek operation is performed in which an interlayer jump is executed after the horizontal movement is performed first.
Here, for example, according to the example of the seek operation in which the interlayer jump is executed before the horizontal movement as described above with reference to FIG. 10, the origin address for performing the horizontal movement must be grasped after the interlayer jump is executed. Rather, an extra process is required. In addition, since the spindle is re-drawn as the horizontal movement starts after the interlayer jump is completed, the spindle lock waiting time also becomes longer, and the seek operation tends to take longer. there were.
In the present embodiment, the above inconvenience is solved. That is, the horizontal movement is performed prior to the interlayer jump, but when the horizontal movement is started at time points t31 and t32, the current address as the position being traced is known so far. Does not need to know the address. Further, with respect to the spindle motor 11, the speed re-drawing can be started at time t32 when both the optical heads 1a and 1b start horizontal movement. As a result of the speed pull-in of the spindle motor 11 being started at an early stage, the time for waiting for the spindle lock at time t35 to t37 and time t36 to t37 is also shortened.
Further, it is not necessary to read the address at time t33 when the optical head 1a performs interlayer jump and at time t34 when the optical head 1b performs interlayer jump.
For these reasons, the time required for the entire seek operation is shortened.

  FIG. 4 shows a processing sequence of the synchronous seek according to the present embodiment as described above. The processing of FIG. 4 is executed by control of the system controller 24 and sequence processing as a synchronous seek by the servo processing unit 16a and the servo processing unit 16b. In particular, steps F101 to F115 are shown as processes executed by the system controller 24 and the servo processing unit 16a, and steps F201 to F215 are shown as processes executed by the system controller 24 and the servo processing unit 16b.

Steps F101 and F201 show a state in which the optical heads 1a and 1b are respectively tracing as a reproducing or recording operation.
For example, when a seek is required by a command from the host device 100, the system controller 24 first issues a seek request for the optical head 1a to the servo processing unit 16a as step F102.
Here, if the target address as the seek target position is an address on the same recording layer as the recording layer currently being traced, no interlayer jump is involved in the seek operation. In this case, the process proceeds from step F103 to F107, and although not described in detail, the servo processing unit 16a executes a seek process only for horizontal movement within the same recording layer.

Further, since the CLV type 2OP system requires a synchronous seek operation, the system controller 24 issues a seek request for the optical head 1b to the servo processing unit 16b in step F202.
If the target address as the seek target position is an address on the same recording layer as the recording layer currently being traced, the servo processing unit 16b also proceeds from step F203 to F207 to perform only horizontal movement within the same recording layer. Perform seek processing.
Since the address information includes information for identifying the recording layer, the recording layer of the seek target address can be determined from the seek target address itself.

  If the target address as the seek target position is an address on a recording layer different from the recording layer that is currently being traced, the system processing starts at step F104 and step F204 in order to start a seek operation with interlayer jump and horizontal movement. Will proceed to.

First, in step F104, the system controller 24 and the servo processing unit 16a confirm the address read by the optical head 1a being traced, and calculate the number of jump tracks as a radial difference from the target address.
In step F105, the servo processing unit 16a turns off the tracking servo and drives the sled mechanism 12a to start the horizontal movement of the optical head 1a to the target track.
At this time, the servo processing unit 16a starts counting the number of jump tracks based on the waveform of the traverse signal obtained as the tracking error signal waveform. That is, counting of the number of tracks crossed by the horizontal movement is started.

On the other hand, in step F204, the system controller 24 and the servo processing unit 16b confirm the address read by the optical head 1b being traced and calculate the number of jump tracks as a radial difference from the target address.
In step F205, the servo processing unit 16b turns off the tracking servo and drives the sled mechanism 12b to start the horizontal movement of the optical head 1b to the target track.
At this time, the servo processing unit 16b starts counting the number of jump tracks based on the waveform of the traverse signal obtained as the tracking error signal waveform. That is, counting of the number of tracks crossed by the horizontal movement is started.
Further, the system controller 24 starts moving the optical head 1b in the horizontal direction at the time of step F205, and instructs the spindle servo circuit 17 to release the lock of the CLV servo, to the CLV speed at the seek target address. The re-retraction of the rotation speed of is started.

The servo processing unit 16a that started the horizontal movement of the optical head 1a in step F105 then continues the horizontal movement of the optical head 1a until the number of jump tracks calculated in step F104 is counted.
Then, at the position where the counted number of jump tracks reaches the number of jump tracks calculated in step F104, the transfer by the sled mechanism 12a is terminated, the tracking servo is turned on, and when the tracking servo is settled, the horizontal movement of the optical head 1a is completed. End of direction movement. At this time, the servo processing unit 16a proceeds from step F106 to F108, and subsequently turns off the focus servo and tracking servo, and executes the forcible movement of the objective lens by the biaxial actuator, thereby performing the interlayer jump of the optical head 1a. Let it run.
At the timing when the interlayer jump is completed, the focus servo is turned on in step F109 so that the laser light from the optical head 1a is in the focused state in the jump-destination recording layer, and the tracking servo is turned on in step F110. To do. In step F111, completion of pulling in the rotational speed of the spindle motor 56 is awaited.

Further, the servo processing unit 16b that has started the horizontal movement of the optical head 1b in step F205 then continues the horizontal movement of the optical head 1b until the number of jump tracks calculated in step F204 is counted.
Then, at the position where the counted number of jump tracks reaches the number of jump tracks calculated in step F204, the transfer by the sled mechanism 12b is finished, the tracking servo is turned on, and when the tracking servo is set, the horizontal movement of the optical head 1b is completed. End of direction movement. At this point, the servo processing unit 16b proceeds from step F206 to F208, and subsequently turns off the focus servo and tracking servo, and executes the forcible movement of the objective lens by the biaxial actuator, thereby performing the interlayer jump of the optical head 1b. Let it run.
At the timing when the interlayer jump ends, the focus servo is turned on in step F209 so that the laser beam from the optical head 1b is in focus in the recording layer to which the jump is made, and the tracking servo is turned on in step F210. To do. In step F211, the process waits for completion of pulling in the rotational speed of the spindle motor 56.

When the retraction of the rotation speed of the spindle motor 56 by the spindle servo circuit 17 is completed and the CLV servo at the seek target position is locked, the system processing proceeds from step F111 to F112 and from step F211 to F212. .
Here, the system controller 24 confirms the address read by the optical head 1a in step F112, and confirms whether or not it matches the seek target address. If they do not match, in step F114, the servo processing unit 16a is instructed to perform a fine adjustment seek (for example, a track jump by a biaxial actuator) to correct the deviation, and the servo processing unit 16a controls the execution.
In step F113, when the read address is determined to be the target address, the seek operation of the optical head 1a is completed, and the process proceeds to a state during tracing shown as step F115.

In step F212, the system controller 24 checks the address read by the optical head 1b, and checks whether it matches the seek target address. If they do not match, in step F214, the servo processing unit 16b is instructed to perform a fine adjustment seek (for example, a track jump by a biaxial actuator) to correct the deviation, and the servo processing unit 16b controls the execution.
When it is determined in step F213 that the read address is the target address, the seek operation of the optical head 1a is completed, and the process proceeds to a state during tracing shown as step F215.

With the above-described procedure, the above-described synchronous seek of the present example is executed as a seek operation involving interlayer jump and horizontal movement.
According to this synchronous seek, the time required for the entire seek can be shortened, thereby improving the recording / reproducing performance of the disk drive device.
It should be noted that the present invention is not limited to the configurations and operations as the embodiments described so far, and various modifications can be considered.
The present invention is also effective in a disk drive device in which three or more head parts such as an optical head are mounted.
In addition, a seek operation with an interlayer jump can be performed in the same manner when three or more recording layers are provided as a disk recording medium.

1 is a block diagram of a disk drive device according to an embodiment of the present invention. It is explanatory drawing of the seek operation | movement accompanied by the interlayer jump and horizontal movement of embodiment. It is explanatory drawing of the synchronous seek operation | movement of embodiment. It is a flowchart of the synchronous seek process of an embodiment. It is explanatory drawing of the interlayer jump operation | movement in a 2 layer disc. It is explanatory drawing of 2OP system. It is explanatory drawing of the head positional relationship in 2OP system. It is explanatory drawing of the seek operation | movement without an interlayer jump in 2OP system. It is explanatory drawing of the seek operation | movement accompanied by the interlayer jump in 1OP system. It is explanatory drawing of the example of seek operation | movement with an interlayer jump in 2OP system.

Explanation of symbols

  1a, 1b Optical head, 11 Spindle motor, 12a, b Thread mechanism, 13 Spindle driver, 14a, b Thread driver, 15a, b 2-axis driver, 16a, b Servo processing unit, 17 Spindle servo circuit, 18a, b Matrix circuit , 19a, b Laser control unit, 20 recording processing unit, 21 host interface, 22 playback processing unit, 23 wobble processing unit, 24 system controller, 90 optical disk, 100 host device

Claims (3)

In a disk drive device that performs recording or reproduction on a disk recording medium having a plurality of recording layers,
A plurality of head units each for reading or writing information to the plurality of recording layers;
A reproduction processing unit that reproduces information read by the plurality of head units;
When performing a seek operation involving both interlayer movement and disk radial movement for the plurality of head parts, each of the plurality of head parts is moved in the disk radial direction, and then interlayer movement is performed. A control unit that performs control to complete the seek operation;
A disk drive device comprising:   2. The control unit according to claim 1, wherein the control unit causes the interlayer movement to be performed without performing a position confirmation operation of the head unit after moving each of the head units in the disk radial direction. Disk drive device. In a disk drive device that performs recording or reproduction with respect to a disk recording medium having a plurality of recording layers, each comprising a plurality of head units that read or write information from or to a plurality of recording layers in the disk recording medium, As a seek method of a disk drive device for recording or reproducing with respect to the disk recording medium,
When performing a seek operation involving both interlayer movement and disk radial movement for the plurality of head parts, each of the plurality of head parts is moved in the disk radial direction, and then interlayer movement is performed. A seek method characterized by completing a seek operation.

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