KR100207425B1 - Circuit for variating a characteristic of a compensator in an optical disc player - Google Patents

Abstract

The present invention relates to a compensator characteristic variable circuit of an optical disc player. The compensator characteristic variable circuit of an optical disc player has a resistor R1 having one end connected to the tracking error detector 200 and the other end connected to the compensator 300. And a resistor R2 connected in parallel with the resistor R1 and the compensator 300, a resistor R4 connected in series with the resistor R2, a capacitor C1 connected in series with the resistor R4, and a resistor. (R4) and a resistor (R3) connected in parallel with the condenser (C1), the resistors (R1-R4) and condensers (C1) are characteristics of the optical pickup portion that is replaced with the existing optical pickup portion when replacing the optical pickup The compensating circuit changes the pickup characteristics according to the replacement of the optical pick-up section, which is selected according to the curve. It works.

Description

Compensator Characteristic Variable Circuit of Optical Disc Player

1 is a schematic block diagram of a conventional optical disc player.

2 is a graph for explaining a method for designing a compensator characteristic variable circuit of an optical disc player according to the present invention from the compensator shown in FIG.

3 is a circuit diagram of a compensator employing a compensator characteristic variable circuit of an optical disc player according to a preferred embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

100 optical pickup unit 200 tracking error detection unit

300: compensator 320: compensator characteristic variable circuit

400: drive motor 500: actuator

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc player, and more particularly, to a compensator characteristic variable circuit of an optical disc player for compensating for a characteristic change of a compensation circuit generated when replacing an optical pickup system in an optical disc player.

Typical optical disc reproducing apparatuses include a compact disc player (CDP), a laser disc player (LDP) and a compact disc graphic player (CDGP). The player is a device capable of playing only audio, and the laser disk player and compact disk graphic player are devices capable of simultaneously playing back video and audio. Recently, a video compact disc player capable of playing video and audio on a disc having the same size as a general compact disc has also been developed and used. In addition, recently, a digital video disc using MPEG-2 video compression technology has been developed. DVDs have been developed, which can record and play back gigabytes (GB) of data, including moving images on optical discs of 12 cm, such as current CDs, and continue to evolve to improve their performance. In addition, there has also been developed an optical disc changer system having a plurality of disc trays and equipped with the same number of discs to read and reproduce data recorded on tracks of each disc in a sequential or random manner.

On the other hand, such optical disc reproducing apparatus reproduces the image and / or audio recorded on the optical disc and outputs it through the screen and / or the speaker, and has a higher signal-to-noise ratio than the conventional image and / or audio reproducing apparatus. It has many advantages such as better signal quality and / or sound quality, no noise caused by irregular playback and modulation, very low distortion, no ghost, and random access. There is a trend that is spreading.

On the other hand, in such a disc player, there is a case where the optical pickup system, that is, the optical pickup unit needs to be replaced. In this case, there is a problem that a conventional design process such as the initial design of the system has to go through.

1 is a schematic block diagram of a conventional optical disc player.

As shown in FIG. 1, a typical optical disc player has a tracking error based on the amount of light of an optical pickup unit 100 that picks up and outputs light from the optical disc, and the amount of picked-up optical signal provided from the optical pickup unit 100. FIG. The tracking error detector 200 detects the error, the compensator 300 outputs a compensation signal for compensating the tracking error according to the tracking error signal provided from the tracking error detector 200, and rotates according to the output signal of the compensator 300. The drive motor 400, the actuator is driven in accordance with the rotation of the drive motor includes an actuator 500 for moving the optical pickup 100 to reduce the tracking error.

In such a conventional optical disc player, replacing the optical pickup unit 100 requires recompensation of the compensator 300, which accurately follows the track of the pitch on the optical disc in order to accurately read data recorded on the optical disc. Play as you go. In other words, when the disc is playing, the light must be accurately tracked along the track when the optical disc is rotated. If this tracking control is not performed smoothly, the sound may be cut off or the screen may be blurred due to shock or disturbance during playback. The compensator for preventing this phenomenon must be redesigned to meet the characteristics of the optical pickup unit to be replaced when the optical pickup unit is replaced. Conventionally, in redesigning such a compensator, the method of analyzing the dynamic characteristic curve of the optical pickup unit, setting a new compensation point, and constructing and applying a circuit was used, but there was a very complicated and cumbersome problem.

Accordingly, the present invention has been made to solve such a problem in the related art, and an object of the present invention is to change the dynamic characteristic curve of the optical pickup portion before the replacement when the optical pickup portion is replaced in the conventional optical disc player. The present invention provides a compensator characteristic variable circuit for an optical disk player that compensates for a change in pickup characteristics due to replacement of an optical pickup unit by configuring a circuit for comparing and deriving a difference therebetween.

According to a preferred embodiment of the present invention for achieving this object, a tracking error is detected based on an optical pickup unit for picking up and outputting light from an optical disk, and the amount of light of the picked-up optical signal provided from the optical pickup unit. A tracking error detector, a compensator for outputting a compensation signal for compensating for a tracking error according to a tracking error signal provided from the tracking error detector, a drive motor rotating according to an output signal of the compensator, and a rotation of the drive motor. An optical disc player including an actuator driven to move the optical pickup unit to reduce the tracking error, thereby compensating the compensator according to the replaced optical pickup unit as the optical pickup unit is replaced. In the compensator characteristic variable circuit, the tracking A first resistor whose one end is connected to the error detecting unit and the other end thereof is connected to the error compensator, a second resistor connected in parallel with the first resistor and the compensator, a third resistor connected in series with the second resistor, And a third resistor connected in series with the third resistor, and a third resistor and a fourth resistor connected in parallel with the capacitor to compensate for pickup characteristics of the replaced optical pickup unit.

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

FIG. 2 is a graph for explaining a method for designing a compensator characteristic variable circuit of an optical disc player according to the present invention from the compensator shown in FIG.

That is, if the characteristic curve of the optical pickup unit before the second (a) diagram is replaced, and the characteristic curve of the optical pickup unit to replace the second (b) diagram, first, as shown in FIG. Similarly, the difference between the characteristic curve of FIG. 2 (a) and the characteristic curve of FIG. 2 (b) is derived.

As shown in FIG. 2 (d), a compensation curve for compensating for the difference is derived and the compensator characteristic variable circuit 320 is configured as shown in FIG. Just connect to

Meanwhile, in FIG. 2 (d), the compensator characteristic variable circuit 320 must be configured such that the interval between the frequency f3 and the frequency f4 is always kept narrow, which is the frequency f3 and the frequency f4. This is because the compensation characteristics of the conventional compensator 300 may be changed when the interval is widened.

That is, as shown in FIG. 3, the compensator characteristic variable circuit of the optical disc player according to the present invention includes a resistor R1 having one end connected to the tracking error detector 200 and the other end connected to the compensator 300. FIG. , A resistor R2 connected in parallel with the resistor R1 and the compensator 300, a resistor R4 connected in series with the resistor R2, a capacitor C1 connected in series with the resistor R4, and a resistor ( R4) and a resistor R3 connected in parallel with the capacitor C1. The values of the resistors R1, R2, R3, and R4 and the capacitor C1 do not change the characteristics of the conventional compensator 300. It should not be enough. That is, the resistors R1, R2, R3, and R4 are maintained such that the interval between the frequency f3 and the frequency f4 shown in the second (d) does not change the characteristics of the conventional compensator 300. ) And the values of the capacitor C1 should be set.

Further, the compensator characteristic variable circuit of the optical disc player according to the present invention changes the values of the circuit elements, that is, the resistors R1, R2, R3, R4 and the capacitor C1 according to the characteristics of the optical pickup to be replaced. Easy to apply

Therefore, the present invention compares the characteristic curve of the optical pickup unit with the optical pickup unit to replace the optical pickup unit when the optical pickup is replaced in the optical disc player, and composes a compensation circuit for compensating for only the portion that is changed to compensate for the existing compensator. There is an effect that can compose a compensation circuit according to the replacement of the optical pickup easily without the hassle of design.

While the invention has been shown and described with reference to certain preferred embodiments, those skilled in the art will recognize that various modifications and changes can occur without departing from the spirit and scope of the invention as set forth in the claims below.

Claims (2)

An optical pickup 100 for picking up and outputting light from an optical disk, a tracking error detector 200 for detecting a tracking error based on the amount of light of the optical signal picked up by the optical pickup 100, and the tracking error A compensator 300 for outputting a compensation signal for compensating a tracking error according to a tracking error signal provided from the detector 200, a drive motor 400 rotating according to an output signal of the compensator 300, and the drive In an optical disc player including an actuator 500 which is driven by the rotation of the motor 400 to move the optical pickup unit 100 so that a tracking error is reduced, the compensator when the optical pickup unit 100 is replaced. In the compensator characteristic variable circuit of the optical disc player for compensating the characteristic of 300 according to the characteristic of the optical pickup to be replaced, one end of the compensator is connected to the tracking error detection unit 200. First resistor R1 connected to the other end of the compensator 300, the second resistor R2 connected in parallel with the first resistor R1, the compensator 300, and the second resistor R2. ) And a third resistor R4 connected in series, a capacitor C1 connected in series with the third resistor R4, and a fourth resistor connected in parallel with the third resistor R4 and the capacitor C1. And a compensator characteristic variable circuit (320) having an R3 to compensate for the pickup characteristic of the optical pickup unit to be replaced. The optical disc player compensator characteristic of claim 1, wherein the values of the first to fourth resistors R1, R2, R3, and R4 and the condenser C1 vary according to the characteristics of the optical pickup to be replaced. Variable circuit.