JPH09306126A - Access device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate an error generated in continuous jump movement by correcting the number of tracks to be jumped over so as to make an N-fold arithmetic means and an addition-subtraction arithmetic means contain no error. SOLUTION: When the number of tracks from the head of a program area to a target track 1 and a track positioned in the present address is obtained respectively by a relative tack calculating means 3, and from this result the number of tracks in existence between their tracks is calculated, a constant in the next place is obtained and is multiplied by the number of tracks calculated by the means 3 by the N-fold arithmetic means 7. This constant is a value obtained by dividing an average jump time interval of a continuous jump moving means 6 by a time of one revolution of a disk in a disk position to perform jumping. When the number of tracks calculated by the means 3 is more than a prescribed value, a traverse moving means 5 is started up by an access control means 4, and when the number of tracks is less than the prescribed value, the means 6 is started up. When the means 6 is started up, a value calculated by the means 7 is added to or subtracted from the number of tracks calculated by the means 3 to correct a pickup in response to its moving direction by the addition-subtraction arithmetic means 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an access device of a disk device for writing or reading information on a disk-shaped recording medium such as a compact disk or an optical disk, and more particularly to an access device for accurately performing continuous jump movement. .

[0002]

2. Description of the Related Art In recent years, disk devices using various optical disks such as compact disks, mini disks and DVDs have been developed. These disc devices incorporate an access device for accurately moving the optical pickup to a position of an arbitrary address on the disc in order to realize functions such as music selection and cueing.

Conventionally, the access device has been disclosed in Japanese Patent Publication No. 57-60.
As described in No. 540, the access time is shortened by appropriately combining high-speed access for jumping a plurality of tracks and low-speed access for jumping one track at a time. An example of a conventional access device for a disk device will be described below with reference to the drawings.

As shown in FIG. 5, the conventional access device has an address detecting means 2 for detecting an address on the disk where the pickup is currently located, and an address detecting means 2.
The relative track calculating means 3 for calculating the amount of the signal tracks existing between the current address and the target address from the current address and the target address 1 output by and the output result of the relative track calculating means 3 completes the access. A high-speed movement of the pickup by driving the traverse motor by the number of tracks designated in the direction designated by the command of the access control means 4 and the access control means 4 for determining whether or how to access. There are provided traverse moving means 5 and a continuous jump moving means 6 for continuously moving the pickup in a designated direction by track jumps by the number of outputs of the relative track calculating means 3 according to a command from the access control means 4.

This access device operates as follows.

When a user performs an operation such as music selection or cueing in a disk device, a target address is designated for the access device. At this time, the target address 1 and the address of the current position of the pickup output from the address detection unit 2 are input to the relative track calculation unit 3 of the access device.

The relationship between the number of tracks and the address Ad is N = {√ (TdtVt / π + R0 ² -R0)} / Td t = (Ad)  (the minimum unit time of the address). Here, N is the number of tracks from the beginning of the program area, Td is the track pitch, RO is the innermost radius of the program area, and Vt is the speed at which the pickup traces the tracks. The relative track calculating means 3 exists between the target address and the current address by calculating the number of tracks from the beginning of the program area for each of the input target address and current address by the above formula and calculating the difference between them. Calculate the number of tracks.

The calculation result of the relative track calculation means 3 is input to the access control means 4. Access control means 4
2, as shown in the flow chart of FIG. 2, it is determined whether or not the track where the current address is located is one step before the track where the target address is located, based on the calculation result of the relative track calculating means 3. If it is one before, the access is terminated.

Step 2: The track of the current address is
If it is not one track before the target address, it is judged whether the number of tracks in the meantime is 128 or more. Step 3: If it is 128 tracks or less, the jump movement of the pickup by the continuous jump moving means 6 is started, If it is larger than 4: 128 tracks, the high speed movement of the pickup by the traverse movement means 5 is started.

As shown in the flow chart of FIG. 4, the traverse moving means 5 starts the high speed movement of the pickup by activating the traverse motor in step 11 after turning off the tracking. Step 12: When a track cross signal generated when the moving pickup crosses a track is detected, Step 13: counts it and decrements the moving amount by the future high speed movement by the count number.

Step 14: Until the predetermined movement is completed,
When the amount of movement due to the high speed movement becomes 0 by repeating the procedure of step 12 and step 13, step 15: stop the traverse motor, step 16: turn on tracking and end the processing.

Further, as shown in the flow chart of FIG. 3, the continuous jump moving means 6 generates a certain amount of acceleration pulse for a certain time and gives it to the tracking actuator. This acceleration pulse accelerates the pickup in the target direction. Step 21: If the track cross signal generated when the pickup crosses the track is detected, Step 22: Decelerate the speed of the pickup by generating a deceleration pulse so that torque is generated in the direction opposite to the acceleration direction. Step 23: Wait for the condition to stabilize for 2 msec, and then Step 24: Decrement the movement amount by the track jump by 1. Step 25: The procedure of steps 20 to 24 is repeated until the movement amount by the track jump becomes 0, and when the movement amount by the track jump becomes 0, the process ends.

[0013]

However, in the conventional access device, it is difficult to accurately move a predetermined number of tracks by the continuous jump moving means 6. In the movement by the continuous jump moving means 6, the track is jumped to the adjacent track of the spiral track at a constant time interval with the tracking turned on. An example of the operation by this continuous jump movement is shown in FIG. When accessing in the outer peripheral direction from the point A in FIG. 6, first, the first jump movement is performed at the point B, and subsequently, the jump is performed at the points C, D, E, and F, respectively.

In this operation example, the jump from the point A to the outer peripheral direction is performed five times to reach the point F, but the track at the point F is located on the outer circumference of six tracks from the track at the starting point A.
That is, the number of tracks actually moving by the time the continuous jump movement is completed becomes larger than the number of jumps. This occurs because the tracking remains on even during continuous jump movement, and the pickup traces the track and continues to move in the outer peripheral direction. Therefore, if the amount of movement is counted according to the number of jumps, more tracks than the original number of movements will be moved. The error thus generated becomes a factor that hinders high-speed access.

The present invention solves these conventional problems, and an object of the present invention is to provide an access device capable of eliminating an error that occurs during continuous jump movement.

[0016]

Therefore, in the access device of the present invention, the relative track calculating means for calculating the number of signal tracks existing between the current position and the target position, and the tracks of this signal track number are continuously connected. It is obtained by providing a calculating means for calculating the number of revolutions of the disc during the jump movement by a proper track jump, and correcting the disc rotation speed with respect to the signal track number calculated by the relative track calculating means. It is configured to execute a continuous track jump by the number.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is an access device for moving a pickup or a head to a target position on a disk on which a spiral track is formed. Relative track calculating means for calculating the number of signal tracks existing between,
N times calculating means for multiplying the calculated number of signal tracks by a predetermined magnification in order to obtain the number of rotations of the disk during the jump movement of the tracks of the number of signal tracks by continuous track jumps; When jumping in the same direction as the movement direction of the pickup or the head when reading the above data, when subtracting the calculation result of the N times calculation means from the calculation result of the relative track calculation means and reading the data on the disk When jumping in a direction different from the moving direction of the pickup or the head, the addition / subtraction calculation means for adding the calculation result of the relative track calculation means and the calculation result of the N-fold calculation means, and only the number of calculation by the addition / subtraction calculation means A continuous jar that moves the pickup or head in a specified direction by continuous track jumps. Are those in which a and flop moving means,
During the movement of the pickup by continuous jump movement, the pickup or the head traces the track during the tracking stabilization time between the jumps, and therefore, the error caused by the pickup moving in the disk radial direction is corrected. You can

According to a second aspect of the present invention, the N-fold calculating means divides the average jump time interval in the continuous jump moving means by the time of one rotation of the disk at the disk position where the jump movement is performed, as the magnification. The value is used, and by multiplying this magnification by the number of signal tracks calculated by the relative track calculating means, the number of rotations of the disk during the jump movement of this number of signal tracks can be obtained. .

According to a third aspect of the present invention, the N times calculating means has an area in which the average jump interval in the continuous jump moving means is divided into M areas of the disk and the jump movement is performed as the magnification. It is configured to use a value divided by the time of one rotation of the disk in the central part of the above, and the calculation can be simplified compared to the second aspect.

According to a fourth aspect of the present invention, the N-fold calculation means uses, as the magnification, a value obtained by dividing the average jump interval in the continuous jump movement means by the time of one rotation in the central portion of the program area of the disk. Thus, the calculation can be further simplified.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
4 to FIG.

The access device according to the embodiment of the present invention, as shown in FIG. 1, includes an address detecting means 2 for detecting an address on the disk where the pickup is currently located,
Relative track calculation means 3 for calculating the number of signal tracks existing between the current address and the target address from the current address output from the address detection means 2 and the target address 1.
And an access control means 4 for judging whether or not the access is to be ended or a method of accessing based on the output result of the relative track calculation means 3, and a direction designated by a command of the access control means 4. The traverse moving means 5 for moving the pickup at a high speed by driving the traverse motor by the number of tracks thus calculated, and the calculation result of the relative track calculating means 3 are multiplied by a predetermined magnification to obtain the disk rotation speed until the completion of the continuous jump movement. The N-fold calculation means 7 to be calculated is subtracted from the calculation result of the relative-track calculation means 3 when the access direction is toward the outer circumference, and the relative result is calculated when the access direction is toward the inner circumference. Addition / subtraction calculation means 8 for adding the calculation result of the N-fold calculation means 7 to the calculation result of the track calculation means 3.
And the addition / subtraction calculation means 8 according to a command from the access control means 4.
The continuous jump moving means 6 for continuously moving the pickup in the designated direction by the track jump by the number of the output lines.

Address detecting means 2 of this access device,
The relative track calculation means 3, the access control means 4, and the traverse movement means 5 perform the same operations as the conventional device (FIG. 5).

The relative track calculating means 3 obtains the number of tracks from the beginning of the program area of the track where the target address 1 is located and the number of tracks from the beginning of the program area of the track where the current address is located. After calculating the number of tracks existing in, the N-fold calculation means 7 calculates the following constant and multiplies it by the number of tracks calculated by the relative track calculation means 3.

This constant is a value obtained by dividing the average jump time interval in the continuous jump moving means 6 by the time of one rotation of the disk at the disk position where the jump is performed. Therefore, by multiplying the number of tracks calculated by the relative track calculating means 3 by this constant, the number of rotations of the disk during the movement of the number of tracks in the continuous track jump can be obtained.

Further, in order to simplify the operation of the N-fold calculation means 7 while maintaining accuracy and realize the access device at low cost, this constant may be calculated as follows.

That is, the radius of the disc is divided into M areas, and the time for one revolution of the disc at the disc position where the continuous jump is performed is defined as the time for one revolution of the disc at the center of the area where the continuous jump is performed. Is approximated using. Therefore, the average jump time interval in the continuous jump moving means 6 is set to 1
The value divided by the rotation time is a constant.

Further, in the case of further simplification, the time for one rotation of the disk at the disk position where the continuous jump is performed is set to 1 at the center of the program area of the disk.
It may be approximated by the time of rotation, and the value obtained by dividing the average jump time interval in the continuous jump moving means 6 by the time of one rotation in the central portion of the program area of the disk may be used as a constant.

According to the flow of FIG. 2, the access control means 4 activates the traverse movement means 5 when the number of tracks calculated by the relative track calculation means 3 is 128 or more, and the continuous jump movement when the number of tracks is 128 tracks or less. The means 6 is activated.

When the continuous jump moving means 6 is activated, the adding / subtracting means 8 calculates the N times calculating means 7 from the number of tracks calculated by the relative track calculating means 3 according to the direction of the jump movement of the pickup. The value is added or subtracted to correct the number of tracks calculated by the relative track calculation means 3.

In the disk device in which the pickup gradually moves in the outer peripheral direction while following the track when reading the data on the disk, when the jump movement is in the outer peripheral direction, the adding / subtracting means 8 calculates the relative track. The value calculated by the N-fold calculation means 7 is subtracted from the number of tracks calculated by the means 3. On the contrary, when the jump movement is directed in the inner circumferential direction, it is added. Further, in the disc device in which the pickup gradually moves in the inner peripheral direction while following the track when reading the data on the disc, when the jump movement is in the outer peripheral direction, the addition / subtraction means 8
Is the number of tracks calculated by the relative track calculation means 3 and N
The value calculated by the double calculation means 7 is added, and conversely, when the jump movement is directed in the inner circumferential direction, it is subtracted. In other words, when the pickup movement direction and the jump movement direction when reading data on the disc are the same,
From the calculation result of the relative track calculation means 3, N times calculation means 7
The calculation result of the relative track calculation means 3 and the calculation result of the N-fold calculation means 7 are calculated in the directions in which the movement direction of the pickup and the jump movement direction when reading the data on the disc are different from each other. to add.

The continuous jump moving means 6 continuously jumps the tracks in the designated direction by the number calculated by the addition / subtraction calculating means 8. This operation is the same as that of the conventional apparatus, and is performed by the flow procedure of FIG.

As described above, in this access device, the N-fold calculation means 7 and the addition / subtraction calculation means 8 for the number of tracks to be jumped by the continuous jump moving means 6 are
Correct so that the error is not included. Therefore, it is possible to quickly and accurately access the predetermined position.

[0034]

As is apparent from the above description, the access device of the present invention can accurately perform continuous track jump movement, improve access accuracy, and increase access speed.

[Brief description of drawings]

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

FIG. 2 is a flowchart showing the operation of access control means,

FIG. 3 is a flowchart showing the operation of the continuous jump moving means,

FIG. 4 is a flowchart showing the operation of the traverse moving means,

FIG. 5 is a block diagram of a conventional access device,

FIG. 6 is an operation example of continuous jump movement.

[Explanation of symbols]

 1 Target Address 2 Address Detecting Means 3 Relative Track Calculating Means 4 Access Control Means 5 Traverse Moving Means 6 Continuous Jump Moving Means 7 N Time Calculating Means 8 Addition / Decrement Calculating Means A Access Origin B 1st Jump C 2nd Jump D 3rd Time Jump E 4th Jump F 5th Jump

Claims (4)

[Claims] 1. An access device for moving a pickup or a head to a target position on a disk on which a spiral track is formed. Relative track calculating means for calculating the number of signal tracks existing between the current position and the target position. And N times calculating means for multiplying the calculated number of signal tracks by a predetermined magnification in order to obtain the number of rotations of the disk during the jump movement of the tracks of the number of signal tracks by continuous track jumps. In the case of jumping in the same direction as the moving direction of the pickup or head when reading the data on the disc, the N is calculated from the calculation result of the relative track calculating means.
When the calculation result of the double calculation means is subtracted and a jump movement is made in a direction different from the movement direction of the pickup or head when reading data on the disc, the calculation result of the relative track calculation means and the N-fold calculation means An access device comprising: an addition / subtraction calculation means for adding the calculation result; and a continuous jump movement means for moving the pickup or the head in a designated direction by continuous track jumps by the number calculated by the addition / subtraction calculation means. . 2. The N-fold calculation means, as the magnification,
2. The access device according to claim 1, wherein a value obtained by dividing an average jump time interval in the continuous jump moving means by a time of one rotation of the disk at a disk position where jump movement is performed is used. 3. The N-fold calculation means, as the magnification,
A value obtained by dividing the average jump interval in the continuous jump moving means by the time required for one rotation of the disk in the central portion of the area where the jump movement is performed within the radius of the disk divided into M areas is used. The access device according to claim 1. 4. The N-fold calculation means, as the magnification,
2. A value obtained by dividing the average jump interval in the continuous jump moving means by the time of one rotation in the central portion of the program area of the disk is used.
An access device according to claim 1.