KR19990026856A - Spindle Motor Control Method in Optical Disc Player - Google Patents

Abstract

The present invention relates to a control method of a spindle motor for maintaining a plurality of programs recorded on each track of an optical disc at a predetermined constant linear speed, the rotation speed (Nn) of the first track of the optical disc and the rotation speed difference between tracks ( Calculating and storing ΔN); When the optical disc is reproduced, the spindle motor is rotated at the rotation speed Nn calculated in the first step, and then sequentially by the track speed difference ΔN calculated in the first step every track. By providing a spindle motor control method for an optical disc player, characterized in that it comprises a second step of reducing the rotational speed of the spindle motor, the spindle directly by operation of the system control unit without relying on the synchronization signal detected by the optical disc player By controlling the motor, the control of the spindle motor can be performed more stably, thereby improving the reliability of the optical disc player.

Description

Spindle Motor Control Method in Optical Disc Player

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc player, and more particularly, the rotation speed of each track of an optical disc for rotating with CLV (Constant Linear Velocity) is calculated directly by the system control unit, and the calculated rotation speed is calculated. The present invention relates to a spindle motor control method of an optical disc player configured to control a spindle motor.

In general, optical disc players include compact disk players (CDPs), laser disk players (LDPs), compact disk graphic players (CDGPs), and video compact disk players (VCDPs). video compact disk player) has been developed and widely used. Also, recently, a digital video disk (DVD) using MPEG-2 moving picture compression technology and a digital video disk player for playing the same have been developed. It can record and play back gigabytes (GB) of data including moving images on a 12cm optical disc such as a CD, and it is also designed to be compatible to play current CDs and VCDs.

Such an optical disc player has been developed to record and reproduce image and audio data on a semi-permanent optical disc as audio and video media have developed.

Such an optical disc player reproduces an image and / or audio recorded on an optical disc and outputs it through a screen and / or a speaker, and has a higher signal-to-noise ratio than conventional image and / or audio reproducing apparatus, resulting in better image quality and / or Or it can reproduce the signal with sound quality, it does not generate noise due to irregular reproduction and modulation, very low distortion, no ghost and random access, so it is rapidly developed and widely distributed. There is a trend.

On the other hand, in the above-described optical disc player, in order to make the disc as small as possible, recording is made to push the same as the inner circumference over the front of the disc, and then the rotation speed of the inner and outer circumferences is changed according to the pickup position. This is called the CLV method.

In order to perform the CLV method, that is, to maintain a constant linear speed, conventionally, the number of revolutions for each track of the optical disc player is changed by using a spindle motor control device as shown in FIG.

The process is briefly described with reference to FIG. 1 as follows.

FIG. 1 is a block diagram illustrating a control device of a general spindle motor. The optical pickup unit 110, the RF signal amplifier 120, the digital signal processor 130, the controller 140, the motor driver 150, It is composed of a spindle motor 160, the operation process is as follows.

First, when the play mode is started after the disc D is chucked to the optical disc player, the controller 140 provides a drive control signal to the motor driver 150 and the optical pickup unit 110.

The motor driver 150 drives the spindle motor 160 when the drive control signal is provided from the controller 140, and the disk D rotates accordingly.

On the other hand, the optical pickup 110 receives the drive control signal from the control unit 140 reads the data signal while tracing the track of the rotating disk 100, and provides the read signal to the RF amplifier 120 do.

The RF amplifier 120 amplifies the signal provided from the optical pickup unit 110 and provides it to the digital signal processor 160, and the digital signal processor 130 transmits the RF signal provided from the RF amplifier 120 to the EFM. While demodulating and performing error detection and error correction, the frame synchronization signal is detected and provided to the controller 140.

The controller 140 checks the period of the frame synchronization signal provided from the digital signal processor 130, and if the period of the frame synchronization signal is greater than a predetermined reference period, the controller 140 controls the motor driver 150 to rotate the disk. If the speed is controlled to be faster, and the period of the frame synchronization signal is smaller than a predetermined reference period, the controller 140 controls the motor driver 150 to control the disk rotation speed to be slow.

The motor driver 150 accelerates or decelerates the spindle motor 160 under the control of the controller, and accordingly, the disk 100 rotates to CLV.

However, in the above-described control method of the spindle motor using the spindle control device, the spindle motor is controlled by using the synchronization signal. Therefore, when the synchronization signal is not detected or the synchronization signal is damaged in the process of reading out the signal from the optical disc, the spindle is damaged. There was a problem that is difficult to control the motor.

Accordingly, the present invention has been made in view of the above-described problems, and an object of the present invention is to calculate the rotation speed of the track on which the optical pickup is located directly from the system control unit so that the optical disk can be controlled by the CLV regardless of the synchronization signal, SUMMARY OF THE INVENTION An object of the present invention is to provide a spindle motor control method in an optical disc player capable of controlling acceleration and deceleration of a spindle motor in response to the calculated rotation speed.

In order to achieve the above object, in the present invention, in the control method of the spindle motor for maintaining a plurality of programs recorded in each track of the optical disk at a predetermined constant linear speed, the rotation speed (Nn) of the first track of the optical disk (Nn) And a first step of calculating and storing the track speed difference ΔN; When the optical disc is reproduced, the spindle motor is rotated at the rotation speed Nn calculated in the first step, and then sequentially by the track speed difference ΔN calculated in the first step every track. And a second step of reducing the rotational speed of the spindle motor.

1 is a block diagram showing a spindle motor control apparatus for a general optical disc player;

2 is a plan view and a sectional view of an optical disk for explaining a method for calculating a rotation speed of a spindle motor in an optical disk player according to the present invention;

3 is a block diagram showing hardware for implementing a spindle motor control method in an optical disc player according to the present invention;

4 is a detailed flowchart showing a spindle motor control method in the optical disk player according to the present invention.

* Explanation of symbols for main parts of the drawings

110: optical pickup unit 120: RF signal amplification unit

130: digital signal processing unit 140: control unit

150: motor drive unit 160: spindle motor

210: key input unit 220: system control unit

230: storage unit 240: optical disc player

T1: first track T2: second track

R1: radius of T1 R2: radius of T2

Ri: Radius of lead-in section ΔR: Half difference between tracks

P: pitch N1: rotation speed of T1

N2: Speed of T2 ΔN: Speed difference between tracks

The above and other objects and advantages of the present invention will become more apparent from the preferred embodiments described below with reference to the accompanying drawings.

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

2 is a plan view and a cross-sectional view of an optical disk for explaining a method for calculating a rotational speed of a spindle motor in an optical disk player according to the present invention, and FIG. 3 is a diagram for implementing a method of controlling a spindle motor in an optical disk player according to the present invention. 4 is a block diagram showing hardware, and FIG. 4 is a detailed flowchart showing a spindle motor control method in the optical disc player according to the present invention.

Hereinafter, each symbol of a plan view and a cross-sectional view of an optical disk for explaining the method for calculating the rotational speed of the spindle motor in the optical disk player according to the present invention will be described briefly. Next, the spindle motor control in the optical disk player according to the present invention will be described. After briefly explaining the configuration of the hardware and the function of each component for implementing the method, the spindle motor control method in the optical disc player according to the present invention implemented using such hardware will be described in sequence. At this time, for the sake of understanding, the same reference numerals will be used for the same constituent members as the general spindle motor control apparatus shown in FIG. 1.

First, FIG. 2 is a plan view and a cross-sectional view of an optical disk for explaining a method of calculating a rotation speed of a spindle motor in an optical disk player according to the present invention, wherein a circle shown by a solid line in the center of the optical disk is formed in the optical disk. ), A plurality of concentric circles shown in dotted lines around a hole are tracks in which a predetermined program is stored, and a solid rectangle shown in the horizontal direction at the bottom thereof shows a cross-sectional view of the optical disc.

Further, T1 and T2 are symbols for designating the first and second tracks set as an example for explaining the present invention among a plurality of tracks formed on the optical disc, and R represents the radius in each of the above-mentioned tracks. Ri is the radius of the read-in area, R1 is the radius of T1, R2 is the radius of T2, and Δr is the pitch between tracks.

On the other hand, Figure 3 is a hardware for implementing the spindle motor control method in the optical disk player according to the present invention, the motor drive unit 150 and the spindle motor 160 to perform the same function as in Figure 1, of FIG. The optical disc player 240 including the optical pickup unit 110, the RF signal amplifier unit 120, and the digital signal processor unit 130 further includes a key input unit 210, a system control unit 220, and a storage unit 230. Each function is as follows.

First, the key input unit 210 is formed with a plurality of keys including a playback key, and generates a key signal corresponding to the key operation of the user's work, and provides it to the system control unit 220, thereby providing the user's desired optical disc. It can be recognized and performed by the player 240.

The system controller 220 controls the overall operation of the optical disc player 240 in response to a signal provided from a key input unit or each component member of the optical disc player 240, and in particular, the spindle motor 160 corresponding to each track of the optical disc. ), The motor drive unit 150 is controlled so that the optical disk can rotate in a CLV manner.

The storage unit 230 stores TOC information read by the optical disc player 240, and stores information about a predetermined linear velocity when the optical disc player 240 executes a program recorded on the optical disc. It is. At this time, the TOC information may include information on the track position of the mounted optical disc.

Hereinafter, a control method of the spindle motor according to the present invention, which is implemented in hardware consisting of constituent members for performing the above functions, will be described.

First, when a predetermined optical disc in which a program is recorded on each track is loaded into the optical disc player 240 (S 10), the optical disc player 240 includes a table of contents stored in a load-in area of the optical disc. ) Information is read and provided to the system control unit 220, and the system control unit 220 stores the TOC information provided from the optical disc player 240 in the internal memory (not shown) or the storage unit provided in the system control unit 220. Stored at 230 (S 20). At this time, the TOC information may include position data for each track of the optical disc.

Thereafter, when the user manipulates the play key provided in the key input unit 210, the key input unit 210 generates a play key signal corresponding to the key operation of the user's work and provides it to the system controller 220. (S30 )

The system controller 220 receiving the reproduction key signal from the key input unit 210 may rotate the spindle motor 160 at the initial position of the program section formed on the optical disk to rotate the optical disk at a constant linear speed. And the rotation speed difference ΔN between tracks. (S 40) At this time, the rotation speed Nn of the spindle motor 160 is calculated as follows.

First, the system controller 220 calculates the radius R1 at the end position of the lead-in section, and the radius R1 will be the radius of the first track T1 of the optical disc. At this time, since the lead-in section is standardized, it may be preset according to the type of optical disc.

In the process of s-1, the system controller 220, which calculates the radius R1 of T1, multiplies R1 by 2π (π = 3.14 ...) to find the circumference of T1.

Thereafter, the system controller 220 divides the predetermined linear velocity Vd by the circumference of T1 obtained in the process of s -2 to obtain the rotation speed N at T1.

Further, the radius difference between tracks is focused on the same point as the track pitch, and the rotation speed difference ΔN between the tracks is obtained by the following equation, and the rotation speed difference ΔN between the tracks is stored in the storage unit 230. s-4)

At this time, since the track pitch P is the distance between the track and the track, the radius difference between one track T (n) and the next track T (n + 1) is equal to the track pitch.

In order to help understand the process of s-1 to s-4 of the above-described S40 step, it will be described again with the siles in the CD as follows.

First, in the case of CD, the track pitch P is about 1.6 μm, and the lead-in section is produced starting at 46 mm in diameter and up to 50 mm. Thus, in the case of the produced CD, for example, when the linear velocity is set to 1.2 m / s, the rotation speed N in each track is as follows.

First, the radius R1 of the first track T1 of the program section will be 25 mm since its diameter is 50 mm at the end of the lead-in section.

Therefore, since 2 x 25 mm x 3.15 = 157 mm, the circumference of T1 is 157 mm.

Since the rotation speed N1 at T1 is 1.2 (m / s) / 157 (mm), in order to maintain the predetermined linear speed 1.2 m / s, the spindle motor 160 should be rotated about 7.643312 per second. That is, the rotation speed N1 of T1 for maintaining the predetermined linear speed is about 458.59872 RPM (Radian Per Minute).

In addition, the rotation speed difference ΔN between tracks can be obtained as follows from the above equation of s-4.

=

=

= 458.56938-458.59872 (RPM) =-0.02934 (RPM)

Therefore, in the case of the above-described CD, in order to maintain a predetermined linear speed of 1.2 m / s, the rotation speed should be reduced by 0.02934 RPM per track.

The above-described examples are only examples for better understanding of the present invention, and it should be noted that the present invention is equally applicable to other optical discs and other linear velocities, because they do not represent the whole of the present invention.

Thereafter, the system controller 220 controls the motor driver 150 to rotate the spindle motor 160 at the rotation speed N1 calculated in step S 40, and the motor driver 150 controls the system controller 220. By the control, the spindle motor 160 is driven to rotate the spindle motor 160 at the rotation speed N1 calculated in step S50. (S50)

Simultaneously with step S50, the system controller 220 moves the optical pickup unit 110 provided in the optical disk player 240 to an initial position of a program section formed on the optical disk, and then starts the playback from the moved position. ).

The optical disc player 240 moves the optical pickup unit 110 to the initial position T1 of the program section formed on the optical disc under the control of the system controller 220, and then starts playback from the moved position T1. In addition, the program recorded on the optical disc is played, and information about the current playback position of the optical disc is provided to the system controller 220. (S60) In this case, the program section includes the actual program of each section of the optical disc. It is a section.

Thereafter, the system controller 220 detects whether another key signal is applied from the key input unit 210 (S70). As a result, when another key signal is applied from the key input unit 210, the system controller 220 corresponds to the applied key signal. The optical disc player 240 is controlled to perform an operation, and the optical disc player 240 performs an operation corresponding to a key signal under the control of the system controller 220 (S 100).

On the other hand, if a key signal is not applied from the key input unit 210 as a result of the detection of step S 70, the system controller 220 may display the information provided from the optical disc player 240 and the TOC information stored in the storage unit 230. With reference to this, it is determined whether the next track position is reached (S80).

As a result of the determination of S 80, if the current playback position of the optical disc player 240 does not reach the next track of the optical disc, the system controller 220 controls the optical disc player 240 to repeat steps S 60 to S 80. The optical disc player 240 repeats steps S60 to S80 under the control of the system controller 220.

On the other hand, if it is determined in step S80 that the current playback position of the optical disc player 240 reaches the next track of the optical disc, the system controller 220 calculates in step S40 and then stores the tracks stored in the storage unit 230. The motor driver 150 is controlled to reduce the current rotation speed Nn of the spindle motor so as to correspond to the difference ΔN of the rotation speed.

The motor driver 150 drives the spindle motor 160 under the control of the system controller 220 to reduce the rotation speed N of the spindle motor 160 by ΔN.

Thereafter, the system controller 220 waits for a key signal input from the key input unit 210 and repeats the above-described steps S50 and S90 until another key signal is generated from the key input unit 210.

According to the present invention described above, the control of the spindle motor is more stably performed by directly controlling the rotation of the spindle motor for maintaining a constant linear velocity by operation of the system controller, without relying on the synchronization signal detected by the optical disc player. It is possible to increase the reliability of the optical disc player accordingly.

Claims (3)

In the control method of the spindle motor for maintaining a plurality of programs recorded in each track of the optical disk at a predetermined constant linear speed, A first step of calculating and storing the rotation speed Nn of the first track of the optical disk and the rotation speed difference ΔN between tracks; When the optical disc is reproduced, the spindle motor is rotated at the rotation speed Nn calculated in the first step, and then sequentially by the track speed difference ΔN calculated in the first step every track. And a second step of reducing the rotation speed of the spindle motor. 2. The spindle motor control method according to claim 1, wherein the number of revolutions (Nn) of the first track of the first step is the quotient of the linear velocity divided by the circumference of the first track. The method of claim 1, wherein the inter-track speed difference (ΔN) of the first step is calculated as a difference between the rotation speed of the first track and the rotation speed of the second track.