KR19980061669A - Feed feed unit of optical disc player - Google Patents

Abstract

The present invention relates to a feed transfer apparatus of an optical disc player for transferring an optical pickup unit (110) for reading an RF signal from an optical disc to a target track, and detects a tracking error of the optical pickup unit (110). A tracking error detector 120 for outputting a tracking error signal; A feed feed servo unit 140 for feeding the optical pickup unit 110; A speed detector 150 for detecting a pulse period of the tracking error signal and calculating a feed feed speed; An A / D converter 160 converting the output of the speed detector 150 into digital; A counter 170 for counting the number of pulses of the tracking error signal; The feed rate table set corresponding to the feed distance between the current track and the target track is stored in the internal memory, and the feed position table determines the current track position by the count value provided from the counter 17, and determines the current position and the target. After calculating the transport distance between the track, the control unit for controlling the feed feed servo unit 140 so that the feed feed rate provided from the D / A converter 160 matches the feed rate set corresponding to the feed distance ( It is characterized by comprising a 180).

Description

Feed feed unit of optical disc player

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc player, and more particularly, to a feed transfer apparatus for transferring an optical pickup unit for reading data from a disc to a predetermined track.

In general, an optical disc system is characterized by a digital recording method and a non-contact reproducing method. More specifically, an optical disc system reproduces and reads a bit signal engraved on an optical disc in a non-contact manner by light, and performs digital signal processing thereon. Therefore, the optical disc system improves performance that is difficult to realize in an analog recording / reproducing system, as well as operability such as random access or program reproduction utilizing non-contact reproduction.

FIG. 1 is a schematic configuration diagram of an optical pickup unit that reads data recorded on a disk and outputs a radio frequency (RF) signal in such an optical disk system.

In Fig. 1, digital information is recorded along the track on the optical disc 11, and the laser beam collected by the objective lens 12 is scanned on the signal surface of the disc 11. In addition, a focusing actuator coil 13 drives the objective lens 12 so that the signal surface of the disk 11 is located within the depth of focus of the laser beam, and the tracking actuator coil 14 is a laser for optical pickup. The objective lens 12 is driven so that the beam can accurately trace along the track of the disc 11.

At this time, the system for driving the objective lens 12 so that the signal surface of the disk 11 is located within the depth of focus of the laser beam is commonly referred to as focusing servo, and the laser beam for optical pickup is accurately aligned along the track of the disk 11. Driving the objective lens 12 so as to be traced is called tracking servo.

The focusing servo uses a focusing error signal representing the degree to which the signal plane of the disc 11 is out of the depth of focus of the laser beam, and the tracking servo generates a tracking error signal indicating the extent to which the laser beam is off track of the disc 11. I use it.

The tracking servo also includes a function of forcibly jumping outward or inward from the current track to search for a desired track. This track jump operation is performed by forcibly applying a jump pulse to the tracking actuator coil 14. At this time, applying the jump pulse to the tracking actuator coil 14 is to apply a force corresponding to the jump pulse, so that the optical pickup unit is accelerated by its force to jump to the desired track.

However, since such a tracking servo has a limitation on the movable range, it is necessary to move the entire optical pickup unit. In addition, when accessing the optical pickup unit to a desired track position on the optical disc 11, it is necessary to quickly move the optical pickup unit to a desired position. In this way, the feed feed servo is used to feed the entire optical pickup unit.

An access technique for quickly approaching a target track position using the above-described track trace, track jump and feed feed servo has been introduced. Once the target track has been determined, this method first moves the optical pickup unit by a long jump near the target track by the feed servo, and then traverses the target track through the track jump. By tracing the target track.

Usually, the feed feed servo uses the tracking error signal described above. That is, when the optical pickup unit is transported across the tracks of the disc, the tracking error signal takes the form of a sine wave, and the number of sine waves corresponds to the number of tracks.

Therefore, when the target track is determined, the number of tracks from the current track to the target track is calculated, and then the number of pulses of the sinusoids calculated by counting the number of pulses of the sine wave generated when the optical pickup unit is transported is determined. Feed transfer is completed by stopping the transfer of the pickup unit.

In such a feed conveyance, the conveyance speed of the optical pickup unit conveyed to the target track was constant. That is, irrespective of the distance between the current track and the target track, once the target track is determined, there is a problem that the optical pickup unit always moves at a constant feed speed and thus falls somewhat in terms of efficiency.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object thereof is to provide a feed feed apparatus capable of more efficient feed transfer by adjusting a feed speed according to a feed distance between a current track and a target track when performing feed feed. .

The present invention provides a feed transfer apparatus of an optical disc player for transferring an optical pickup unit that reads an RF signal from an optical disc to a target track, in order to achieve the above object: A tracking error of the optical pickup unit is detected and tracking corresponding thereto. A tracking error detector for outputting an error signal; A feed feed servo unit for feeding the optical pickup unit; A speed detector for detecting a pulse period of the tracking error signal and calculating a feed feed speed; An A / D converter converting the output of the speed detector into digital; A counter for counting the number of pulses of the tracking error signal; A feed rate table set to correspond to the transfer distance between the current track and the target track is stored in the internal memory, so that the current track position is determined by the count value provided from the counter during feed transfer, and the transfer between the current position and the target track is performed. After calculating the distance, characterized in that it comprises a control unit for controlling the feed feed servo unit so that the feed feed rate provided from the D / A conversion unit is matched with the feed rate set corresponding to the feed distance.

1 is a block diagram of a feed transfer device according to an embodiment of the present invention.

<Description of the code | symbol about the principal part of drawing>

100: optical disk 110: optical pickup unit

120: tracking error detection unit 130: tracking servo unit

140: feed feed servo unit 150: speed detection unit

160: A / D conversion unit 170: counter

180: control unit

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

2 is a block diagram of a feed transfer device according to an embodiment of the present invention, an optical pickup unit 110 for reading a radio frequency (RF) signal from an optical disc 100, an optical disc 100, and an optical pickup unit The tracking error detection unit 120 detects a tracking error of the 110 and outputs a tracking error signal corresponding thereto, and a tracking servo unit that controls a track trace of the optical pickup unit 110 when a tracking error signal is provided. 130, a feed feed servo unit 140 for transferring the optical pickup unit 110, and a speed detector 150 for detecting a pulse period of the tracking error signal output from the tracking error detector 120 to calculate a feed feed speed. A counter 170 for counting the number of pulses of the tracking error signal output from the A / D (Analog / Digital) converter 160 for converting the output of the speed detector 150 into digital, the tracking error detector 120, Current track and target track The feed rate table set to correspond to the feed distance between the two is stored in the internal memory, and is set to correspond to the feed distance to the target track by referring to the feed feed rate provided from the D / A converter 160 during feed transfer. The optical pickup unit 110 is transported at the feed rate, and the feed value is stopped when the optical pickup unit 110 reaches the target track by determining whether the optical pickup unit has reached the target track using the count value of the counter 170. The controller 180 is configured to control the feed feed servo unit 140 to be possible.

The operation description of the feed transportation device configured as described above is as follows.

First, when a target track for feed transfer is determined, the controller 180 calculates a transfer distance between the current track and the target track on the optical disc 100. Thereafter, a feed speed set corresponding to the calculated feed distance is detected by referring to a table stored in the internal memory, and the feed feed servo unit 140 is controlled to feed the optical pickup unit 110 at the detected feed speed.

The feed feed servo unit 140 transfers the optical pickup unit 110 to the target track under the control of the controller 180. As the optical pickup unit 110 is transported, the tracking error detector 120 generates a tracking error signal of a certain sinusoidal wave. The speed detector 150 detects each period of the tracking error signal, calculates a feed rate, that is, a feed rate of the optical pickup unit 110, and provides a corresponding signal to the A / D converter 160. The A / D converter 160 converts a signal corresponding to the feed rate into digital and provides the converted signal to the controller 180.

In addition, the counter 170 counts the number of pulses of the tracking error signal and provides a corresponding signal to the controller 180. The controller 180 calculates a movement distance between the target track and the current track by referring to the number of pulses of the tracking error signal provided from the counter 170 and then corresponds to the calculated travel distance by referring to a table stored in the internal memory. The set feed rate is compared with the feed feed rate provided from the A / D converter 160.

As a result of the comparison, if the feed feed rate provided from the A / D converter 160 is faster than the moving speed detected from the memory, the feed feed speed is lowered, and the feed feed speed provided from the A / D converter 160 is the memory. If it is slower than the movement speed detected from the control feed feed servo unit 140 so that the feed feed speed is faster.

Through this process, the optical pickup unit 110 may approach the target track. The controller 180 searches whether the optical pickup unit has reached the target track by referring to the count value of the counter 170, and when the optical pickup unit 11 has reached the target track, the feed transfer servo unit may terminate the feed transfer. 140).

As described above, the present invention has an effect that a more efficient feed feeding can be achieved by adjusting the feeding speed according to the feeding distance between the current track and the target track during feed feeding.

Claims (1)

In a feed transfer apparatus of an optical disc player for transferring an optical pickup unit that reads an RF signal from an optical disc to a target track: A tracking error detector 120 for detecting a tracking error of the optical pickup unit and outputting a tracking error signal corresponding thereto; A feed feed servo unit 140 for feeding the optical pickup unit 110; A speed detector 150 for detecting a pulse period of the tracking error signal and calculating a feed feed speed; An A / D converter 160 converting the output of the speed detector 150 into digital; A counter 170 for counting the number of pulses of the tracking error signal; The feed rate table set to correspond to the transfer distance between the current track and the target track is stored in the internal memory, and the feed position table determines the current track position by the count value provided from the counter 170, and determines the current position and the target. After calculating the transport distance between the track, the control unit for controlling the feed feed servo unit 140 so that the feed feed rate provided from the D / A converter 160 matches the feed rate set corresponding to the feed distance ( Feed feed apparatus for an optical disc player having a 180)