KR19980030552A - Focus gain setting device of optical disc player - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus gain setting device of an optical disc player, and includes a sine wave of 1 KHz and 1 V provided from a disturbance generator 10 and a disturbance generator 10 that output a sine wave signal of 1 KHz and 1 V (volt). The signal output from the driver 120 is added based on the first band pass filter 50 for band-pass filtering the signal and outputting the signal, based on the output signal of the compensator 110 and the disturbance signal provided from the disturbance generator 10. Adder 70 for outputting the signal, the second band pass filter 60 for outputting the band pass filter of the output signal of the adder 70, and output signals for the first and second band pass filters 60 and 70. Each input terminal (X, Y) is received and displayed as a predetermined waveform, if the gain from the gain control unit 160 is configured to include an oscilloscope (30) to display in the Lissajous waveform.

Therefore, the present invention has an effect of smoothly setting the focus gain by displaying the displayed Lissajous waveform without distortion such as distortion in setting the focus gain in the optical disc player.

Description

Focus gain setting device of optical disc player

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus gain setting device of an optical disc player. More particularly, the focus gain setting of an optical disc player makes it possible to smoothly set the focus gain by displaying the Lissajous waveform displayed on the oscilloscope without distortion for setting the focus gain. Relates to a device.

Typical optical disc players include a compact disk player (CDP), a laser disk player (LDP), a compact disk graphic player (CDGP), and a video compact disk player (VCDP). : Video compact disk player) is developed and used. Generally, compact disk player is a device that can play audio only, and laser disk player, compact disk graphic player and video compact disk player can play video and audio at the same time. to be.

Recently, digital video disks (DVDs) using MPEG-2 moving picture compression technology have been developed, which have a gigabytes (GB) capacity including moving pictures in a 12 cm optical disc such as a current CD. Data can be recorded and reproduced, and there is a continuing trend to improve its performance.

On the other hand, such optical disc players reproduce images and / or audio recorded on the optical disc and output them through a screen and / or a speaker, and have a higher signal-to-noise ratio than conventional image and / or audio reproducing apparatus, resulting in better image quality. And / or can reproduce signals with sound quality, generate no noise due to irregular reproduction and modulation, have very little distortion, no ghosts, and random access. There is a trend that is spreading.

On the other hand, in such an optical disc player, optical is used to read data as described above. In order to read the data recorded accurately on the optical disc, the optical disc player must accurately focus the light on the data surface recorded on the optical disc. That is, it is necessary to follow the focus of the light according to the surface vibration according to the rotation of the optical disk, that is, the vertical movement of the disk.

Therefore, in such an optical disc reproducing apparatus, a fosker servo apparatus is adopted to focus the light irrespective of the vertical vibration of the optical disc, which focuses the optical disc used to read data recorded on the optical disc surface. The optical pickup unit, that is, the objective lens, is moved up and down in accordance with the movement of the optical disk to focus the light accurately on the surface of the optical disk, thereby accurately reading the data recorded on the optical disk.

On the other hand, in order for the focus servo device as described above to be adopted in the optical disc player to smoothly perform the focus sub, the focus gain for performing the focus servo during reproduction must be set at the time of manufacturing the optical disc player.

1 is a schematic block diagram of a conventional focus gain setting apparatus for setting such a focus gain.

As shown in FIG. 1, a conventional focus gain setting device includes a disturbance generator 10 generating a 1 KHz sine wave of 1V (volt) as a disturbance and a band for bandpass filtering the output signal of the disturbance generator 10. Band pass filtering of the output signal of the focus servo system 100 and the focus servo system 100 for processing and outputting the phase-modulated 1V and 1KHz sine wave provided from the disturbance generator 10 and the pass servo system 100. The bandpass filter 20 and the oscilloscope 30 for receiving and outputting the output signals provided from the bandpass filters 20 and 40 through the input terminals X and Y and processing the received signals through Lissajous' waveforms. ).

Meanwhile, the focus servo system 100 is a conventional focus servo device, and includes a focus gain adjuster (not shown) that adjusts and sets the focus gain by having a waveform displayed on the oscilloscope 30 be a Lissajous waveform. In addition, the output signal of the disturbance generator 10 is provided as an input of a driving unit (not shown) for driving a focus actuator (not shown) that substantially performs focus in the focus servo system 100, The output signal is provided as an input signal of the bandpass filter 20.

That is, the focus gain setting device adjusts the focus gain adjusting unit of the focus servo system 100 such that the waveform displayed on the oscilloscope 30 becomes a Lissajous waveform while the user observes the waveform displayed on the oscilloscope 30, When the Lissajous waveform is displayed, the setting of the focus gain is completed.

As a result, the adjustment of the focus gain is to set the focus gain to a gain value in which the phase is shifted 90 degrees through the sinusoidal focus servo system 100 output from the disturbance generator 10 to form a Lissajous waveform. .

2 is a diagram showing an example of the Lissajous waveform displayed on the oscilloscope 30 described above.

Substantially, although the Lissajous waveform displayed on the oscilloscope 30 in the error-free focus gain setting device appears without distortion as shown in FIG. 2A, the conventional focus gain setting device as described above is external or when the focus gain is set. If there is a predetermined influence from the inside, as shown in FIG. 7B, a distortion phenomenon in which the Lissajous waveform is distorted may occur, and thus the focus gain may not be set properly.

Accordingly, the present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a distortion-free Lissajous waveform when a focus gain is set in a focus gain setting device for setting focus gain in an optical disc player. Accordingly, an object of the present invention is to provide a focus gain setting device of an optical disc player for smoothly setting the focus gain.

According to a preferred embodiment of the present invention for achieving the above object, a drive unit driven according to a predetermined drive signal, and moved up or down in accordance with the drive of the drive unit and substantially picked up by performing the focus of the light from the disk. A focus actuator for outputting an optical signal, a focus error detector for detecting and outputting a focus error signal from an output signal of the focus actuator, a pre-amp for amplifying an output signal of the focus error detector to a predetermined level, and the pre- A gain control unit for determining a focus gain for compensating for the focus error signal amplified to a predetermined level by an amplifier, and a compensation signal for compensating the focus error according to the focus gain adjusted by the gain control unit; Focus book including a compensator provided to the drive unit In the device, in the focus gain setting of the optical disk player apparatus to set the focus gain is adjusted is determined by the gain control unit, the gain control unit the user or author manually driven to a focus gain setting, and; A 1KHz, 1V (volt) sine wave signal that outputs a sine wave signal of 1KHz, 1V (volt), and a 1KHz 1V sine wave signal output from the disturbance generator are provided to the drive unit as a disturbance, and a 1KHz, 1V (volt) sine wave provided from the disturbance generator A first bandpass filter for bandpass filtering and outputting a signal, an adder for adding and outputting a signal output from the driver based on an output signal of the compensator and a disturbance signal provided from the disturbance generator, and an output of the adder A second band pass filter for band-pass filtering the signal and outputting the signal, and output signals of the first and second band pass filters to two input terminals and displayed in a predetermined waveform, but the gain control unit When set to gain, it includes an oscilloscope that displays a Lissajous waveform.

1 is a block diagram schematically showing a focus gain setting device of a conventional optical disc player.

2 shows examples of Lissa waveforms displayed on an oscilloscope in a focus gain setting device.

3 is a block diagram of a focus gain setting device of an optical disk player according to a preferred embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

10: Disturbance Generator 20, 40, 50, 60: BPF

30: oscilloscope 70: adder

110: compensation unit 120: driving unit

130: focus actuator 140: focus error detection unit

150: pre-amp 160: gain control unit

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

3 is a detailed block diagram of a focus gain setting apparatus of an optical disc player according to a preferred embodiment of the present invention.

As shown in FIG. 3, the focus gain setting apparatus of the optical disk player according to the present invention band-passes a sinusoidal signal provided from the disturbance generator 10 and the disturbance generator 10 generating a sinusoidal signal as a disturbance in a predetermined band. A first band pass filter (BPF) for filtering and outputting the output signal from the driver 120 according to the output signal of the compensator 110 and the disturbance signal provided from the disturbance generator 10. An adder 70 for adding a signal, a second BPF 60 for bandpass filtering the output signal of the adder 70 to a predetermined band, and output signals for the first and second BPFs 50, 60, respectively. X and Y) and includes an oscilloscope 30 that displays a Lissajou's waveform when gain adjustment is completed in the gain adjusting unit 160.

The driving unit 100 is driven according to a predetermined driving signal, that is, a composition signal provided from a controller (not shown), and the power of the driving unit 120 is provided to the focus actuator 130. Then, the focus actuator 130 moves upward or downward in accordance with the driving of the driving unit 120 to substantially focus the light from the disk and output the picked-up optical signal to the focus error detector 140.

In addition, the focus error detection unit 140 detects a focus error signal from the output signal of the focus actuator 130 and provides it to the pre-amplifier 150, and the pre-amplifier 150 outputs the output signal of the focus error detection unit 140. Amplifies to a predetermined level to provide a gain adjusting unit 160.

The gain adjusting unit 160 determines a focus gain for compensating for this according to a focus error signal provided by being amplified to a predetermined level from the pre-amplifier 150, which is substantially adjusted by setting a gain value for the focus servo. For this purpose, according to the present invention, the gain value when the waveform displayed on the oscilloscope 30 becomes a complete Lissajous waveform as shown in Fig. 2A is set as the focus gain.

In addition, the compensator 110 provides a compensation signal for compensating for a focus error according to the focus gain adjusted by the gain adjuster 160 to the driver 120, and accordingly the focus actuator according to the driving of the driver 120. The 130 is driven in the up or down direction to execute the optical pickup in the focused state.

On the other hand, according to the present invention, the disturbance generator 10 provides a sinusoidal signal of 1KHz, 1V (volt) to the driver 120, and also provides to the first BPF (50). In addition, the first BPF 50 band-pass filters the 1KHz and 1V sine wave signals provided from the disturbance generator 10 to a predetermined band and provides them to the input terminal X of the oscilloscope 30.

In addition, the adder 70 adds an output signal output from the driver 120 based on the output signal of the compensator 110 and the disturbance signal provided from the disturbance generator 10, and provides the added signal to the second BPF 60. Accordingly, the second BPF 60 band-pass filters the output signal of the adder 70 to a predetermined predetermined band and provides it to the input terminal Y of the oscilloscope 30.

On the other hand, the oscilloscope 30 receives and processes the output signals of the first and second band pass filters 50 and 60 to the respective input terminals X and Y, and displays them in a predetermined waveform. When the gain adjustment at 160 is completed, the display shows a Lissajous waveform as shown in FIG. 2A to indicate that the gain adjustment is completed. Accordingly, the user sets the focus gain to the gain value.

As a result, the sine wave focus servo system 100 output from the disturbance generator 10 is phase inverted by 90 degrees so that the oscilloscope 30 appears as a Lissajous waveform.

In addition, according to the present invention, by adding the output signal of the output signal compensation unit 110 of the second BPF (60) and the output signal of the driving unit 120, the signal passing through the first BPF (60) is oscilloscope (30) This prevents the display of a distorted Lissajous waveform at.

As described above, the present invention has an effect of smoothly setting the focus gain by displaying the displayed Lissajous waveform without distortion, such as distortion, in setting the focus gain in the optical disc player.

Claims (1)

A drive unit 120 driven according to a predetermined drive signal, and a focus actuator 130 that moves upward or downward in accordance with the drive of the drive unit 120 to substantially focus light from the disc to output the picked-up optical signal ), A focus error detector 140 for detecting and outputting a focus error signal from the output signal of the focus actuator 130, and a pre-amplifier 150 for amplifying the output signal of the focus error detector 140 to a predetermined level. ), A gain adjusting unit 160 for determining a focus gain for compensating for the focus error signal amplified to a predetermined level from the pre-amplifier 150, and adjusted by the gain adjusting unit 160. In the focus servo device including a compensation unit 110 for providing a compensation signal to the driver 120 to compensate for the focus error in accordance with the focus gain, the gain In the focus gain setting apparatus of the optical disc player for setting the focus gain is determined and adjusted by the adjusting unit 160, The gain adjusting unit 160 is manually driven by the user or the manufacturer to set the focus gain, A disturbance generator 10 for outputting a sine wave signal of 1 KHz and 1 V (volt); 1KHz, 1V sine wave signal output from the disturbance generator 10 is provided to the drive unit 120 as a disturbance, A first band pass filter (50) for band-pass filtering the sine wave signal of 1 KHz, 1 V (volt) provided from the disturbance generator (10); An adder (70) for adding and outputting a signal output from the driver (120) based on the output signal of the compensation unit (110) and the disturbance signal provided from the disturbance generator (10); A second band pass filter 60 for band-pass filtering the output signal of the adder 70; Receive the output signal of the first and second band pass filter (60, 70) to each input terminal (X, Y) and display in a predetermined waveform, the gain desired by the gain adjusting unit 160 A focus gain setting device of an optical disc player including an oscilloscope (30) for displaying a Lissajous waveform when set to.