KR100506461B1 - DVD Fast Seek Method - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to a SEEK method in a system using a DVD, and more particularly, calculates a current pickup position in a central processing unit, calculates a travel distance of a pickup based on a difference from a target position, After calculating the running speed), calculate the disk rotation speed at the target point, input the calculated movement distance value to the servo, and simultaneously supply the calculated disk rotation speed value to the spindle motor drive for disk rotation through the counter. By controlling the disk rotation speed at the target position while the pickup moves to the target point, a method of seeking at high speed by simultaneously performing the movement of the pickup and controlling the disk rotation speed has been proposed.

In particular, the present invention has the effect of being able to seek at high speed by simultaneously performing the movement of the pickup and the disc rotational speed control.

Description

DVD Fast Seek Method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of seek (SEEK) in a system using a DVD (Digital Video Disc: referred to as DVD). It relates to a high speed seek method.

In the above-described seek operation, the pickup for reading information from the disc is moved from the current position to another position.

Generally, the DVD device plays the disc data using the CLV (CONSTANT LINEAR VELOCITY: CLF) method, so the line speed for playing the disc is constant, but the disc speed varies depending on the distance from the center of the disc. The speed of rotation changes. Therefore, the rotation speed of the disc should be changed according to the position of the pickup that reads information from the disc. In this method, the time interval of a signal read from the disc is compared with the reference time by comparing the time interval of a specific signal among the signals read by the pickup. If the disk is longer than the reference time, the disk rotates slowly, so the rotation speed is increased. If the time interval of the signal read from the disk is shorter than the reference time, the disk rotates quickly, so the proper speed is maintained by slowing the rotation speed.

The conventional seek method uses a method of calculating the distance from the current position to the target position, moving the pickup by the calculated distance, and then controlling the rotational speed of the disc when the target position of the seek is determined on the disc. Since the pickup position becomes the target position, when the seek with a large distance difference is made, the rotational speed of the disc is large, and thus it takes a long time to change the rotational speed of the disc, resulting in slow seek.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has proposed a high-speed seek method of a DVD that enables faster seek by controlling the rotational speed of the disc to correspond to the target position while the pickup moves to the target position. .

The present invention as described above,

A first step of calculating, by the central processing unit, the moving distance of the pickup by calculating the current pickup position by the difference with the target position;

A second step of calculating the disk rotational speed at the target point after inputting the movement distance (seeking distance) and inputting the calculated movement distance value of the pickup to the servo;

Simultaneously supplying the calculated disk rotational speed value to the disk rotation spindle motor drive through a counter to control the disk rotational speed to the rotational speed at the target position while the pickup moves to the target point at the same time as the second step. Steps are performed to simultaneously control the movement of the pickup and the rotation speed of the disc.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

EXAMPLE

1 is a block diagram showing the structure of a general DVD system, including a disk storing information, a pickup unit 1 for reading and outputting information stored on the disk with a laser diode, and an output terminal of the pickup unit 1; An analog / digital converter 2 connected to the analog / digital converter 2 for converting and outputting an analog signal output from the pickup unit 1 into a digital signal, and connected to an output terminal of the analog / digital converter 2, A digital signal processor (3) which receives the output digital signal, extracts a synchronous signal, performs demodulation and error correction of data, and outputs the digital signal processor (3). It receives the actual data signal output from (3) and outputs it to the external system and outputs the signal input from the external system to the central processing unit (5). Is connected to an output interface of the external interface section 4 and the digital signal processing section 3 and the external interface section 4 in accordance with a command from an external system input through the external interface section 4 in accordance with a command from the digital signal processing section 3. Is connected to the output of the central processing unit 5 and the analog / digital converter 2 and the central processing unit 5 to output a control signal for performing DVD seek by analyzing the address signal output from the Servo 6 for receiving the signals output from the converter 2 and the central processing unit 5 to control the pickup unit 1 by the input signal, and a reference signal for generating and outputting a reference signal of the disk rotation speed. It is connected to the signal output terminal of the generator 8, the reference signal generator 8, and the digital signal processor 3, and receives and compares the speed signals outputted from the reference signal generator 8 and the digital signal processor 3. By that As a result, a comparator 7 outputting a control signal and a counter connected to the output terminals of the comparator 7 and the central processing unit 5 and receiving the control signals output from the comparator 7 and the central processing unit 5. 9) a counter 9 for adjusting and outputting a value; a digital / analog converter 10 for receiving a digital signal output from the counter 9 and converting the analog signal into an analog signal and outputting the digital signal; A driving unit 11 connected to an output terminal of the digital / analog converter 10 and receiving a signal output from the digital / analog converter 10 and outputting a corresponding motor 12 driving signal; and an output terminal of the driving unit 11. And a motor 12 which is connected to and rotates the disk according to the signal output from the drive unit 11.

The method for performing faster seek in the DVD system as described above includes a first method of reading an external command for designating a target position from the central processing unit 5 through the external interface unit 4, as shown in FIG. Step S1; A second step (S2) of reading the current position signal from the digital signal processor (3) in the central processing unit (5) after the first step (S1); A third step (S3) of calculating a distance to be moved from the difference between the target position and the current position after the second step (S2); A fourth step S4 of calculating a rotational speed of the spindle motor 12 at the target position after the third step S3; A fifth step S5 of calculating a control value corresponding to the rotational speed of the spindle motor 12 at the target position after the fourth step S4; A sixth step (S6) of changing the rotational speed of the motor (12) by outputting a control value calculated in the fifth step (S5) and a control signal for using the control value to the counter (9); A seventh step (S7) of outputting a control signal to the servo (6) after the sixth step (S6) to move the pickup by a distance corresponding to the distance calculated in the third step (S3); An eighth step (S8) of repeating the operation of the sixth step (S6) if it is not the target position by checking whether the pickup position is the target position after the seventh step (S7); When the pickup position is the target position in the eighth step S8, the output of the control signal output to the servo 6 and the counter 9 is stopped to stop the pickup movement, and the rotational speed of the motor 12 is normalized. The ninth step (S9) to be made.

That is, the seek operation is performed faster by controlling the rotational speed of the motor 12 to the rotational speed of the motor 12 at the target position while moving the pickup.

In the above-described high speed seek process in the DVD system, the central processing unit 5 drives the motor 12 to rotate the disk, and the data stored in the disk is read by the pickup.

The analog data output from the disk by the pickup is converted into a digital signal through the analog / digital converter 2 and input to the digital signal processing section 3, and the digital signal processing section 3 is input from the analog / digital converter 2. The data is analyzed and the speed signal is output to the comparator 7, the address information signal is output to the central processing unit 5, and the actual data signal is output to the external interface unit 4, and the digital signal processor is output from the external interface unit 4. The data input in (3) is output to the external system, and the command signal input from the external system is input to the central processing unit 5.

In the above, when there is no command signal input from the external system through the external interface unit 4 to the central processing unit 5 or when there is no need to move the pickup (when there is no seek operation), the control of the rotational speed of the disc is performed. 7), the rotation speed of the disc is controlled by the central processing unit 5 when there is no need to move the pickup (when there is no seek operation).

The rotation speed control process of the disc by the comparator 7 receives the speed signal output from the digital signal processor 3 and the reference speed signal output from the reference signal generator 8 from the comparator 7 and compares the speed signal. As a result, the control signal is output to the counter 9.

The control signal output from the comparator 7 to the counter 9 means that the disk rotates slowly if the time interval of the signal read from the disc is longer than the reference time, so that the rotation speed is increased, and the time interval of the signal read from the disc is referenced. If it is shorter than the time, the disk rotates quickly and generates a control signal to slow down the rotation speed.

When the control signal as described above is input from the comparator 7, the counter 9 controls the rotational speed of the disc by adding or subtracting the output value to the drive unit 11.

Disc rotation speed control process (seek process) by the central processing unit 5, when the seek command signal and the timely signal at the desired position is input from the external system to the central processing unit 5 through the external interface unit (4) The central processing unit 5 receives the address information data output from the digital signal processing unit 3, calculates a current pickup position, and then inputs the target position inputted from the external interface unit 4 and the current calculated above. The position value is used to calculate the distance that the pickup should move, the disk rotational speed at the target position, and a control signal for causing the disk rotational speed to be the calculated rotational speed, and at the counter 9 the central processing unit ( 5) outputs a control signal to the counter 9 to use only the control signal output from 5) and to keep the output value constant, and at the same time The control signal is output to the servo 6.

The servo 6 moves the pickup position by a distance corresponding to the control signal input from the central processing unit 5, and the counter 9 is fixed by the disk rotation speed control signal input from the central processing unit 5. The disk rotational speed control value (value such that the rotational speed of the disk becomes the rotational speed at the target position) is outputted to the drive unit 11 to control the rotational speed of the disk.

When the seek operation as described above is completed, the disc rotation speed control by the comparator 7 is performed again.

As described above, the present invention, in particular, has the effect of being able to seek at high speed by simultaneously performing the movement of the pickup and the disc rotation speed control.

1 is a block diagram showing a configuration of a general DVD device;

2 is a flowchart showing a fast seek method in the DVD apparatus of the present invention.

<Description of the symbols for the main parts of the drawings>

1 pickup unit 2 analog / digital converter

3: digital signal processing unit 4: external interface unit

5: central processing unit 6: servo

7: comparator 8: reference signal generator

9: counter 10: digital / analog converter

11 drive unit 12 motor

Claims (1)

A first step of calculating a current pickup position in a central processing unit controlling high-speed seek, subtracting the calculated current pickup position and a target position, and calculating a movement distance of the pickup; A second step of calculating the disk rotational speed at the target point after inputting the movement distance (seeking distance) and inputting the calculated movement distance value of the pickup to the servo; Simultaneously supplying the calculated disk rotational speed value to the disk rotation spindle motor drive through a counter to control the disk rotational speed to the rotational speed at the target position while the pickup moves to the target point at the same time as the second step. DVD high-speed seek method characterized in that the step of performing the movement of the pickup and the control of the rotation speed of the disc by performing the steps.

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