KR19990026857A - How to Navigate a Track in an Optical Disc Player - Google Patents

Abstract

The present invention is directed to a track search method of an optical disc player configured to control to rotate an optical disc at the target track at a predetermined linear speed when searching for and playing a predetermined target track in a current track of the optical disc performing a predetermined operation. A first step of, when the target track is set, searching for the target track and calculating the number of revolutions of the spindle motor on the target track; And a second step of controlling the spindle motor such that the spindle motor rotates at the rotational speed calculated in the first step at the same time as the search for the target track is completed. Thus, the track search speed of the optical disc player can be increased.

Description

How to Navigate a Track in an Optical Disc Player

The present invention relates to a track search method of an optical disc player, and more particularly, to a track search method of an optical disc player capable of searching and reproducing a target track at high speed by shortening the control time of the 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, and recently, a digital video disk (DVD) using MPEG-2 video compression technology and a digital video disk player for playing the same have been developed. In addition to recording and playing back gigabytes (GB) of data, including moving images, on a 12 cmw optical disc such as a current CD, the CD and VCDs are compatible.

Such an optical disc player has been developed to record and reproduce video and audio data on a semi-permanent optical disk as audio and video media have developed. Or by outputting through the speaker, the signal to noise ratio is higher than the conventional video and / or audio playback devices can reproduce the signal with a better image quality and / or sound quality, there is no noise caused by irregular playback and modulation, It is rapidly developing and widely used due to various advantages such as very little distortion, no ghost, and random access.

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.

On the other hand, the optical disc player provides various functions for the user's convenience. One of the functions provided in the optical disc player, 'browse play', jumps directly from the target track desired by the user in the currently playing track. It is a function that can be performed.

Conventionally, in performing such search reproduction, first, after the target track is searched, the above-described control of the spindle motor is performed so that the optical disk can rotate to CLV in the state where the search is completed.

However, in the conventional method, since the spindle control is performed while the search is completed, there is a problem that it takes a long time to search and play the target track.

Accordingly, the present invention has been made in view of the above-described problems, and an object of the present invention is to rotate an optical disc at a target rotational speed on a target track simultaneously with the optical pickup transfer to a target track when performing a search function on the optical disc. The present invention provides a track search method of an optical disc player system that is configured to be able to be configured.

In order to achieve the above object, in the present invention, during the search and playback of a predetermined target track in the current track of the optical disk performing a predetermined operation, it is possible to control the optical disk in the target track to rotate at a predetermined constant linear speed A track search method of an optical disc player, comprising: a first step of, if the target track is set, searching for the target track and calculating the number of revolutions of the spindle motor on the target track; And a second step of controlling the spindle motor such that the spindle motor rotates at the rotational speed calculated in the first step at the same time as the search for the target track is completed. do.

1 is a block diagram showing a control device of a typical spindle motor,

2 is an exemplary view showing a plan view of an optical disc for explaining a track searching method of an optical disc player according to the present invention;

3 is a block diagram showing hardware for implementing a track search method for an optical disc player according to the present invention;

4 is a detailed flowchart illustrating a track searching method of the optical disc 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

Tn: Current Track To: Target Track

R (h): Radius of hole R (n): Radius of current track

R (o); The radius of the target track

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, in order to help the understanding of the present invention, a part added in the present invention to the above description of FIGS. 1 and 2 will be described in more detail, and the present invention will be described with reference to FIGS. 3 and 4. The same reference numerals are used in FIG. 3 for the same structural members as in FIG. 1.

FIG. 2 is a plan view showing a plane of an optical disc, in which a circle shown by a solid line in the center of the optical disc is a hole formed in the optical disc, and a plurality of concentric circles shown in dotted lines around the hole contain a predetermined program. It is a track.

In addition, Tn indicates the current track on which the optical pickup unit is currently working, To indicates the target track to be searched, and R indicates the radius in each of the tracks described above. In particular, Rn represents the radius of the current track Tn, Ro represents the radius of the target track To, and Δr represents the radius difference between the tracks.

3 is a block diagram of hardware for implementing a track search method of an optical disc player according to the present invention, wherein the motor driving unit 150 and the spindle motor 160 performing the same functions as those 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 navigation key and a selection key. The key input unit 210 generates a key signal corresponding to a user's key operation and provides the key control unit 220 to the system control unit 220 so that the user's desired The bar may be recognized and performed by the optical disc player 240.

The system controller 220 controls the overall operation of the optical disc player 240 in response to a signal provided from the key input unit 210 or each component member of the optical disc player 240, and in particular, the search key from the key input unit 210. When the signal is applied, the rotation aberration between the tracks of the optical disc is calculated to control the motor driving unit 150 to allow the optical disc to rotate in the 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 user's key operation and provides the generated key signal to the system controller 220 (S30).

The system controller 220 receiving the playback key signal from the key input unit 210 controls the optical disk player 240 to play a program recorded on the mounted optical disk, and the optical disk player 240 controls the system controller 220. The program recorded in each track of the optical disc is reproduced by (S40).

If the search key signal is applied from the key input unit 210 by the user's key operation during the playback operation in step S40 (S50), the system controller 220 instructs the user to search for the target track. The optical disc player 240 is controlled to display character information, and the optical disc player 240 may display predetermined character information through a display unit (not shown) provided by the control of the system controller 220. will be.

Accordingly, the user will set the desired target track To by operating the selection key included in the key input unit 210 while viewing the displayed text information. (S60)

When the target track To is set in step S 60, the system controller 220 calculates the rotation speed of the spindle motor in the target track To to rotate the optical disk at a constant linear velocity in the target track To. .

Here, the method of calculating the rotation speed No of the spindle motor 160 in the target track To is 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.

Thereafter, the system controller 220 multiplies the number of tracks Δt between the current track Tn and the target track by the inter-track rotation aberration ΔN, and adds the number of revolutions in the current track Tn to the multiplied value. The rotation speed No in the target track can be obtained (s-5). At this time, the number of tracks Δt between the current track Tn and the target track To may be known from the TOC information read and stored in step S20.

To help understand the process of s-1 to s-5 in step S40 described above, the CD will be described with reference to the following.

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)

In the case of the CD described above, 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.

Therefore, if the rotation speed Nn of the spindle motor 160 in the current track is 5,5 RPM and the track number Δt is 5 tracks, in the target track, the spindle motor (5.5 + (5 x 0.02934) RPM) is used. 160) You will have to rotate it.

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 optical disc player to search for the target track To set in step S 60, and rotates the spindle motor 160 at the rotation speed calculated in step S 70 described above. The motor driver 150 is controlled.

Under the control of the system control unit 220, the optical disc player 240 searches for the target track To, and the motor drive unit 150 rotates at the number of revolutions No in the target track To calculated in step S70. The spindle motor 160 is driven to rotate. (S 80)

Thereafter, the system controller 220 determines whether the search for the target track To is completed in step S 80, and determines whether the spindle motor 160 rotates at the rotational speed No at the target track To (S). 90). As a result of the determination, when the search for the target track To is completed, and the spindle motor 160 rotates at the rotational speed No at the target track To, the optical disc player 240 causes the target track ( To be controlled to perform playback, and the optical disc player 240 performs playback on a program recorded in the target track To under the control of the system controller 220 (S 100).

According to the present invention described above, by performing the control of the spindle motor simultaneously with the search for the target track, the time required for the control of the spindle motor can be shortened, so that the track search speed in the optical disc player can be improved. have.

Claims (4)

A track search method of an optical disc player configured to control to rotate an optical disc at the target track at a predetermined linear speed when searching for and playing a predetermined target track in a current track of an optical disc performing a predetermined operation. A first step of searching for the target track and calculating the rotational speed of the spindle motor in the target track when the target track is set; And a second step of controlling the spindle motor such that the spindle motor is rotated at the rotational speed calculated in the first step at the same time as the search for the target track is completed. The method of claim 1, wherein the spindle motor speed calculation in the target track, A first step of calculating inter-track rotational aberration of the optical disc; A second step of calculating the number of tracks between a current track and a target track of the optical disc; And a third process of multiplying an increase in the number of track-to-track spindle motors calculated in the first process and the number of tracks between the current track and the target track computed in the second process. The track searching method of claim 2, wherein the rotation speed difference between tracks of the first process is calculated as a difference between the rotation speed of the first track and the rotation speed of the second track. 4. The method of claim 3, wherein the number of revolutions of the first track is the quotient of dividing the linear velocity by the circumference of the first track.