KR100263605B1 - Track jump generating device - Google Patents

Abstract

PURPOSE: A generating device for a track jump is provided to locate an optical pickup at an identified track through identifying a track jump pulse per rotation with a final sector of each track in a disk apparatus. CONSTITUTION: A servo control unit(3) controls an operation of a spindle motor(4) for converting an index pulse from the spindle motor into rectangular wave. A four-dividing circuit(2) divides the rectangular wave for generating a pulse per rotation. A time delay circuit(7) delays the pulse output from the dividing circuit for a specific time. A control unit allows an optical pickup to jump one track by rotating of a disk according to the delayed pulse. Herein, the control unit sets the delay time of the delay circuit for zero at an initial state. Then, the delay time is calculated by reading a corresponding sector to establish a delay time for the time delay circuit.

Description

Track Jump Generator

1 shows a track shape of a disk having a spiral structure.

2 is a block diagram of a conventional track jumper.

3 is a timing diagram according to the configuration of FIG.

4 is a block diagram of a track jumper according to the present invention.

5 is a timing diagram according to the configuration of FIG.

Figure 6 is a diagram comparing the track jump according to the prior art and the present invention.

* Brief description of the main parts of the drawing

1: central processing unit 2: 4 division circuit

3: Servo control unit 4: Spindle motor

5: disc 6: optical pickup

7: time delay circuit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording and reproducing apparatus, and more particularly, to a track jump generating apparatus which always keeps an optical pickup on the same track during rotation in a disk apparatus having a spiral track structure.

In recent years, optical information recording and reproducing apparatuses have been used for recording and reproducing information on an optical recording medium with high density using light beams from optical pickups instead of recording and reproducing information using magnetic heads.

As shown in FIG. 1, a disc-shaped recording medium (hereinafter referred to as a disc) is composed of tracks formed in concentric circles or spirals, and sectors divided at regular angles in a radial direction from the center thereof. Different track numbers are given at positions where one rotation is made, and each track has a certain number of sectors, and the recording area is divided by these track numbers.

In a disc having such a spiral structure, track numbers at other positions are detected while a predetermined track is held at the time of rotation of the disc. Due to the movement on the track due to this rotation, the original track is kept constant by a kick back operation that returns the optical pickup to the previous track position during each rotation as shown in FIG.

This operation is necessary because when the optical pickup follows the track by the ontrack operation, the optical pickup continues outward along the track as the disk rotates.

Therefore, in order to solve such a problem, it is necessary to jump one track inward to compensate for one track moved by the spiral track structure at each rotation of the disc in order to keep the optical pickup at the same position.

In order to solve this problem, a track jump generator having the configuration shown in FIG. 2 is conventionally used. Referring to the configuration of the track jumper in FIG. 2, 5 is a disk having a spiral structure used for recording or reproducing information, 4 is a spindle motor for rotating the disk at a constant speed, and 3 is a spindle. Servo control unit that controls the speed of the motor and changes the output waveform of the Hall element output from the spindle motor into square wave, 2 divides the quadrature wave output from the servo control unit and generates 4 pulses per revolution. An optical pickup used for reproducing information from the light reflected by the incident light and recording the information on the disk, and 1 is a central processing unit (CPU) that controls the operation of the entire constituent devices.

The track jump operation in the above apparatus will be described with reference to the timing diagram of FIG. 3.

The servo control unit 3 sends a control command to the spindle motor 4, whereby the spindle motor rotates at a predetermined speed and at the same time rotates the disk 5 having a spiral structure. When the spindle motor 4 is rotated, a predetermined waveform is output to the servo controller 3 by a hall element installed therein, and the servo controller 3 outputs the output waveform from the spindle motor 4 by a square wave indicated by a in FIG. It converts to and outputs a square wave having 4 pulses per revolution.

The square wave output from the servo control unit 3 is input to a four-dividing circuit 2 for dividing the signal frequency by 1/4, and is converted into one pulse per one revolution of the disk as b in FIG. This signal is applied to the interrupt terminal of the central processing unit 1. The applied signal causes the central processing unit 1 to apply a waveform such as c in FIG. 3 to the tracking actuator terminal of the optical pickup 6 so that the optical pickup 1 jumps in by one track.

However, as described above, when one track is jumped every one revolution of the disc, the track jump occurs at any sector within the track, so that even if the address is checked by reading the track number, the track is jumped by ± 1 track. Error is caused by the performance of the track jump.

As a result of this error, it is not located on the correct track after searching, and therefore, even when reading data, it takes a rotation waiting time to start reading before one or two tracks, which is disadvantageous in access time.

It is therefore an object of the present invention to provide an apparatus for eliminating errors caused by one track jump per revolution in a disk apparatus having a spiral structure.

Another object of the present invention is to provide an apparatus in which the optical pickup is always located on the same track by matching the start point of one track jump pulse per revolution with the final sector of each track in a disk apparatus having a spiral structure.

In order to achieve the above object, the track jump generating apparatus according to the present invention uses information from the disk 6 to the optical pickup 6 having a spiral track structure that is rotated by the drive of the spindle motor 4. An optical information recording / reproducing apparatus for recording or reproducing, comprising: a servo controller for controlling driving of the spindle motor and converting index pulses from the spindle motor into square waves; A four-dividing circuit for dividing four square waves from the servo control unit to generate pulses per revolution; A time delay circuit for delaying a pulse output from said four-dividing circuit by a predetermined time; And a controller for one track jump of an optical pickup for one revolution of the disc according to a pulse output by the time delay circuit, wherein the controller sets the delay time of the delay circuit to zero in an initial state. When the initial pulse from the time delay circuit is read, the corresponding sector is read without a track jump of the optical pickup, the delay time is calculated, and the delay time for the time delay circuit is set.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

4 is a block diagram of a track jumper according to the present invention. In FIG. 4, the disk 5, the spindle motor 4, the servo controller 3, and the four-dividing circuit 2 have the same configuration as that of the conventional track jump generator shown in FIG. The difference in the elements is the time delay circuit 7 connected between the four-dividing circuit 2 and the central processing unit 1 and the control between the time delay circuit 7, the central processing unit 1 and the optical pickup 6. Is in.

At this time, the time delay circuit 7 has an ID reading function for identifying a sector and a function for giving a time delay as required, and the central processing unit 1 can calculate a required time delay according to a sector number. It further has a data port for setting the function and the calculated value in the time delay circuit 7.

Hereinafter, the operation of the present invention will be described in more detail with reference to FIG. 5 showing a timing diagram according to the configuration of FIG. 4 and FIG. 4 showing the configuration of the present invention.

In the initial state, the central processing unit 1 sends a reset signal through f to set the delay time of the time delay circuit 7 to zero. The initial operation transmits a control command from the servo control unit 3 to the spindle motor 4 as in the conventional configuration, whereby the spindle motor rotates at a predetermined speed and at the same time rotates the disk. When the spindle motor 4 rotates, a certain waveform is output to the servo control unit 3 by a hall element installed therein, and the servo control unit 3 outputs the output waveform from the spindle motor 4 as a square wave indicated by a in FIG. It converts and outputs a square wave with four pulses per revolution.

The square wave is input to a four-dividing circuit (2) that divides the signal frequency into quarters, and is converted into one pulse per one revolution of the disk as shown in b of FIG. 3, and this signal is interrupted by the central processing unit (1). Is applied to the terminal. However, in the present invention, the applied signal causes the central processing unit to apply a waveform such as c in FIG. 3 to the tracking actuator terminal of the optical pickup so that the optical pickup 1 jumps in one track in the middle of the track. Unlike the prior art, which occurs, the sector ID of the disk is read at this point instead of jumping by one track at the beginning, thereby reading the sector ID of the next sector when the jump occurs.

As shown in FIG. 5A showing the sector number in the track at the time of reading, the sector number read during the jump operation in the middle of any sector "K-1" becomes "K". At this time, if the disk has L sectors for each track, and the rotation speed of the disk is M rpm (rpm), the CPU 1 reads from the read value K and the known values L and M as follows. The delay time to be set in the time delay circuit can be calculated (the delay time is 0 when K = 0).

In the present invention, the time delay circuit 7 serving to delay the track jump time according to the signal of the delay time calculated from the central processing unit 1 is composed of a general counter and logic, and the delay time calculated by the above equation. The counter value capable of producing this value is set by the central processing unit 1 through the f line.

That is, as shown in a of FIG. 3, when a square wave (B in FIG. 5) divided by the four-dividing circuit 2 is applied to the time delay circuit 7 by one rotation of the spindle motor 4, the time delay circuit ( 7) sends a signal to the interrupt terminal of the central processing unit 1, the central processing unit 1 controls the optical pickup 6 according to the interrupt signal, reads the information on the disk, and identifies the ID of the next sector at the position where the jump is to be performed. Read and calculate the delay time according to the above formula.

The calculated delay time is applied to the delay circuit 7 via the data port terminal of the central processing unit. After the pulse is supplied to the time delay circuit 7 through the four-dividing circuit 2 again by one rotation of the spindle motor 4, the time delay circuit 7 delays the pulse by the time set by the above formula ( E of FIG. 5, this interrupts the central processing unit so that the optical pickup is jumped by one track.

That is, the track jump operation on each sector of the track jump operation by the conventional track jump generator according to the present invention and the configuration of FIG. 2 will be described with reference to FIGS. As shown, a track jump operation occurs in any sector in the track (the fourth sector in the figure), and jumps to the same sector of the tracks by one. Therefore, even when the address is read by reading the ID, an error of about +1 track occurs.

However, in the case of the present invention as shown in C of FIG. 6, the above problem can be solved because the track jump is made in the last sector (L-1 th sector) in the truck.

In this way, by using the time delay circuit to delay the index pulse from the spindle motor to match the last sector in the track, the optical pickup is always on the same track after the on-track, so that the track jump operation is performed in the conventional way. It is possible to reduce the rotation waiting time by overcoming the access time problem caused by reading the rotation waiting from at least one to two tracks due to the ± 1 track error.

Claims (3)

An optical information recording / reproducing apparatus for recording or reproducing information by using an optical pickup 6 through a disc 6 having a spiral track structure rotated by the drive of the spindle motor 4, wherein the spindle motor ( A servo control unit 3 for controlling the driving of 4) and converting the index pulse from the spindle motor 4 into a square wave; A four-dividing circuit (2) for dividing four square waves from the servo controller (3) to generate pulses per revolution; A time delay circuit (7) for delaying a pulse output from said four-dividing circuit (2) for a predetermined time; And a controller (1) for one track jump of an optical pickup for one rotation of the disc according to the pulse delayed by the time delay circuit (7), wherein the controller (1) has the delay circuit in the initial state. The delay time of (7) is set to 0, and when the initial pulse from the time delay circuit 7 is read, the corresponding sector is read out without track jump of the optical pickup, and the delay time is calculated to determine the delay time for the time delay circuit 7. A track jump generator, characterized in that for setting a delay time. 2. The track jump generator according to claim 1, wherein one track jump of the optical pickup occurs in the last sector of the track. The track jump generator according to claim 1, wherein the delay time set in said time delay circuit (7) is set by the following equation.