KR970011406B1 - Apparatus for controlling high speed long track jump of an optical recording media system - Google Patents

Abstract

A track jump controller for an optical record medium reproduction system effectively controls a lens vibration generated when an optical pick-up performs a long track jump to a target track. The track jump controller includes: a frequency/voltage converter(12) for converting a frequency of a mirror signal to a voltage; a high pass filter(13) for detecting a high frequency component being an error component; inverting/non-inverting amplifiers(20,21) for inverting/non-inverting an error signal of a high frequency component from the high-pass filter(13); a second switch(30) switched to either the amplifier(20) or the amplifier(21) according to a control signal of the microcomputer(50); and a first switch(31) switched to either a tracking phase complementary circuit(40) or the second switch(30) =Accordingly, the track jump controller complements/amplifies a detected error component from the mirror signal generated during a high-speed long track jump, and outputs it to a tracking coil(TC).

Description

Track jump control device of optical record carrier

1 is a diagram showing a track jump control apparatus for an optical recording medium reproducing system according to an embodiment of the present invention.

2 is a flowchart for explaining the operation of the apparatus shown in FIG.

3A is a view showing the recording surface and the flat surface of the optical recording medium.

FIG. 3B shows an ideal mirror output waveform. FIG.

FIG. 3C shows the mirror output waveform according to the tracking direction vibration of the lens when the optical pickup has a high speed long track jump.

FIG. 4 is a view showing a mirror output waveform after frequency / voltage conversion by the F / V converter of the apparatus shown in FIG.

FIG. 5 is a diagram showing an output waveform of an error component of a mirror signal after filtering by a high pass filter among the apparatus shown in FIG. 1, and the error component being inverted and non-inverted.

* Explanation of symbols for main parts of the drawings

10: recording signal reading unit 11: RF amplification / signal processing unit

12: frequency / voltage converter 13: high pass filter

20: inverted amplifier 21: inverse amplifier

30: second switching unit 31: first switching unit

40: tracking phase compensation circuit unit 50: microcomputer

60: key input section R1, R2: resistance

Q1, Q2: transistor, TC: tracking coil

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a track jump control apparatus for an optical recording medium reproducing system, and more particularly, to an optical recording which effectively controls the vibration of a lens generated when a long track jump is performed on a target track. A track jump control apparatus for a media playback system.

In general, the tracks of optical recording media such as laser discs (LD), compact discs (CD) and magneto-optical discs are arranged at very fine intervals of approximately 1.6 μm, and the number of such tracks is one hour of discs. There are approximately 20,000 tracks. Therefore, if you look at the disk microscopically, it is a realistic problem that there is no choice but to rotate with eccentricity.

The function of the tracking servo is to inject the laser beam while accurately finding the track, and the basic operation of the circuit is to move the objective lens and the optical pickup body in the radial direction based on the electrical signal corresponding to the light reception state of the laser beam. By modifying the position of the track to be tracked.

There are two methods of moving the beam: the optical pickup main body and the objective lens in the lateral direction. The electrons have a large inertial mass, which makes it impossible to move quickly, but instead it can move largely. . In the latter case, the actuator (objective lens and drive unit) is light in weight, and thus high-speed response is possible, but the movable range is narrow, and thus the distance to which the actuator can be moved is limited. Therefore, in the case of jumping a track, first, the pickup body is moved by the delivery motor to set the rough position, and then the target track is captured. Next, the delivery motor is restarted to correct the pickup position so that the objective lens is at the center of the optical system.

However, in the same apparatus operating as described above, when the optical pickup performs the long crack jump, the focusing operation of the focus servo which keeps the distance between the optical recording medium and the pickup constant is performed continuously. Since the tracking operation of the tracking servo is turned off for a long time, the lens vibrates in the tracking direction, which is not desirable, and in the worst case, the lens collides with the drive system so that the focus servo is not operated. There is a risk of departure.

Accordingly, the present invention has been made in view of the above circumstances, and when optical pickup performs a long track jump on a target track, unlike the conventional art, a mirror read and signal-processed by optical pickup without turning off the tracking servo The track jump control device of the optical recording medium reproducing system which can effectively control the vibration in the tracking direction by converting the frequency of the signal into voltage and extracting and compensating only the error component occurring in the high frequency component of the converted mirror signal. The purpose is to provide.

According to the track jump control apparatus of the optical recording medium reproducing system of the present invention for achieving the above object, a recording signal reading section (10) for optically reading data recorded on the optical recording medium, and the recording signal reading RF amplification / signal processing unit 11, which amplifies the recording data read out by the output unit 10 and performs a predetermined signal processing, and a tracking phase compensation for receiving a tracking error signal generated at the time of a tracking error and compensating for the phase thereof and outputting it. A differential amplifier (OP) for differentially amplifying the tracking error signal phase-compensated by the tracking phase compensation circuit unit (40) with a reference level signal, and an amplifier circuit for amplifying the differential amplifier signal of the differential amplifier (OP). An optical recording medium reproducing apparatus having a tracking coil (TC) driven by (Q1, Q2) and a tracking servo control signal from the amplifying circuits (Q1, Q2), wherein the RF recording apparatus performs the tracking control operation. Frequency / voltage converter 12 which receives the frequency of the mirror signal among the signals processed and output by the width / signal processing unit 11 and converts it into voltage, and error component of the voltage signal from the frequency / voltage converter 12. High pass filter 13 for extracting only the high frequency component, inverted / non-inverted amplifiers 20 and 21 for inverting or non-inverting amplified error signals output from the high pass filter 13, and microcomputers. The tracking phase compensation circuit unit 40 according to the control signals of the second switching unit 30 and the microcomputer 50 which are switched to one of the inverting / non-inverting amplifiers 20 and 21 according to the control signal of 50. The first switching unit 31 may be further switched to any one of the second switching unit 30 to compensate / amplify an error component extracted from the mirror signal generated during the high speed long track jump to output the tracking coil. It becomes possible.

Here, the second switching unit 30 is inverted amplification unit 20 when the long tracking jump direction of the current optical pickup is a forward tracking jump (that is, the optical pickup is moved outward) under the control of the microcomputer 50. ), And in the case of the reverse tracking jump (that is, the optical pickup is from the outside to the inside), the non-inverting amplifier 21 is selected.

In the first switching unit 31, the tracking phase compensation circuit unit 40 is selected in the case of the normal playback mode or the long track jumping under the control of the microcomputer 50, and the second switching unit in the case of the long crack jumping. The unit 30 is to be selected.

In addition, the differential amplifier OP selects a tracking error signal phase-compensated by the tracking phase compensation circuit unit 40 or a mirror error signal amplified by the inverting or non-inverting amplifiers 20 and 21 and a reference level signal. Differential amplification.

In addition, NPN transistor Q1 and PNP transistor Q2 are selectively provided in the tracking coil TC according to the vibration component of the mirror error signal input to the non-inverting input terminal (-) of the differential amplifier OP. "On" so that a current flows in a direction opposite to the vibration direction.

Therefore, according to the present invention configured as described above, when the optical pickup is a long track jump to the target track, the lens of the lens according to the inertial force during the long track jump while maintaining the focus servo and tracking servo continuously on, unlike the conventional By extracting and compensating only the error component of the mirror signal due to vibration and adding it to the tracking coil, it is possible to ensure accurate tracking during long crack jumping.

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

FIG. 1 shows a track jump control apparatus for an optical recording medium reproducing system according to an embodiment of the present invention, wherein reference numeral 10 in the drawing shows an optical pickup device for optically reading data recorded on the optical recording medium. A recording signal reading section, 11 is an RF amplification / signal processing section for amplifying a signal read out by the recording signal reading section 10 and processing it into a predetermined form, and 12 is a signal amplification section from the RF amplification / signal processing section 11; A frequency / voltage converter for transmitting only a frequency of the mirror signal among the output signals and converting the signal to a voltage level corresponding thereto, and 13 denotes a fast long crack jump among the voltage level signals of the mirror signal from the frequency / voltage converter 12. The high pass filter extracts only the high frequency component of the voltage level signal caused by the vibration of the lens of the optical optical pickup device.

In the figure, reference numeral 20 denotes an inverting amplifier for inverting and amplifying the high pass component from the high pass filter 13, and 21 denotes a non-inverting amplification for the high pass component from the high pass filter 13; 30 is a non-inverting amplifier, and when the jump direction of the recording signal reading unit 10 jumps from the inside to the outside, the switching contact is switched to the inverting amplifier 20 under the control of the microcomputer 50 and the When the jump direction of the recording signal reading unit 10 is the inner periphery from the outside, the switching contact point is the second switching unit which switches the switching contact toward the non-inverting amplifier 21 under the control of the microcomputer 50, and 31 is the present invention. When the tracking control state of the optical recording medium reproducing system used for the high speed long crack jump is selected, the switching contact point is selected as the second switching unit 30, and in the case of the normal tracking control, the tracking phase compensation circuit unit 40 Selection Is a portion the first switching.

FIG. 2 is a flowchart for explaining the operation of the apparatus shown in FIG. 1, and FIG. 3A shows the recording surface and the flat surface of the optical recording medium, and FIG. Figure 3 shows the mirror output waveform, Figure 3 (C) shows the mirror output waveform according to the tracking direction vibration of the lens when the optical pickup is fast fast cracking, Figure 4 is a F of the device shown in Figure 1 Figure 5 shows the mirror output waveform after frequency / voltage conversion by the / V converter, and FIG. 5 shows the output waveform of the high frequency component of the mirror signal after being filtered by the high pass filter among the devices shown in FIG. A diagram showing the inverted and non-inverted amplified components.

Next, the operation of the present invention will be described in more detail with reference to the drawings.

First, when the long track jump of the optical pickup is made from the inside to the outside, as shown in FIG. 1, the switching contact of the first switching unit 31 is controlled by the microcomputer 50 to the second switching unit 30. At the same time, the switching switching state (that is, c1 to a1 state) and the switching contact point of the second switching unit 30 are switched to the inverting amplifier 20 (ie, c2 to a2 state).

Next, when the recording signal reading unit 10 which is the optical pickup is long track jumped, the recording signal reading unit 10 is read out by the vibration of the lens of the optical pickup and the RF amplification / signal processing unit 11 is performed. A change is generated in the mirror signal, which is the read signal of the flat surface shown in FIG. 3A, among the signals that are amplified / processed and output as shown in the waveform diagram of FIG.

Here, when vibration does not occur in the lens of the optical pickup, as shown in FIG. 3B, an accurate waveform corresponding to the flat surface shown in FIG. 3A is output.

Next, referring to the waveform diagram of FIG. 3, the mirror signal output waveform from the RF amplification / signal processing unit 11 at the time of vibration generation will be described. As shown in Fig. 3C, when the vibration component generated in the moving direction is applied to the moving speed from the inner circumference to the outer circumference of the optical pickup, the pulse width t1 'for the mirror signal at this time is normal (i.e., no vibration). By narrowing the pulse width t1 of the state), the relationship of t1> t1 'is established. Subsequently, the vibration of the lens occurs in the moving direction of the optical pickup (ie, the tracking direction) as described above, and becomes free of vibration components at a predetermined time (a), and then reverses the moving direction of the optical pickup (ie, the inner direction). In this case, the vibration component generated in the opposite direction to the moving direction of the optical pickup is applied, and the pulse width t1 " for the mirror signal is normal (i.e., no vibration) than the pulse width t1. By narrowing, the relationship of t1 "> t1 is established.

Therefore, at this time, the output waveform which is frequency / voltage converted and output by the frequency / voltage converter 12 shown in FIG. 1 is initially based on the potential level of the mirror signal when it is ideal as shown in FIG. As shown in FIG. 3C, when the vibration occurs to the outside, the pulse period becomes faster, and the potential level larger than the potential level for the mirror signal is output, and then the vibration occurs to the inside starting from the non-vibration state (a). As a result, the vibration noise component in the sine wave state is loaded on the basis of the potential level of the mirror signal which causes the pulse period to be slowed.

Then, only the vibration component is extracted while passing through the high pass filter 13, and the waveform is output as shown in FIG.

Thereafter, the vibration component outputs the inverted-amplified waveform as shown in FIG. 5 while passing through the inverted amplifier 20 connected to the output side of the high pass filter 13, and the first switching switched second switch. Mirror signal potential level in the case of the non-vibration state inputted to the inverting input terminal (-) of the differential amplifier OP through the unit 30 and the first switching unit 31 and to the non-inverting input terminal (+). Is differentially amplified from the reference potential level set by the resistor R2, and a signal level smaller than the reference potential level is first input at the time of outward oscillation among the noise components of FIG. 5, so that the output of the differential amplifier OP ". Accordingly, among the NPN and PNP transistors Q1 and Q2 connected to the output terminal of the differential amplifier OP, the PNP transistor Q2 is turned "on" so that the current direction is connected to one of the tracking coils TC. Through the tracking coil TC, the current flows to the potential (-V _EE ) lower than the ground power level through the emitter terminal and the collector terminal of the transistor Q2.

Here, when the optical pickup moves from the inner circumference to the outer circumference when the current flows from the common contact between the emitter terminal of the NPN transistor Q1 and the collector terminal of the PNP transistor Q2 toward the ground via the tracking coil TC. In this case, since the current flows in the tracking coil TC in the direction opposite to the vibration direction, the vibration component is canceled.

On the other hand, when the long track jump of the optical pickup is made from the outside to the inside, as shown in FIG. 1, the switching contact of the first switching 31 is controlled by the microcomputer 50 to the second switching unit 30. The switching switching state (ie, c1 to a1 state) and the switching contact point of the second switching unit 30 are switched to the non-inverting amplifier 21 (ie, c2 to b2 state).

Next, when the recording signal reading unit 10, which is an optical pickup, is rock-cracked, it is read by the recording signal reading unit 10 due to vibration of the lens of the optical pickup, and the RF amplification / signal processing unit 11 is read. As a result of the amplification / processing and outputting the mirror signal, which is the read signal of the flat surface shown in FIG. 3A, as shown in the waveform diagram of FIG. 3C, a change occurs.

Next, referring to the waveform diagram of FIG. 3, the mirror signal output waveform from the RF amplification / signal processing unit 11 at the time of vibration will be described. First, since the vibration of the lens is issued inward in the traveling direction of the optical pickup. As shown in Fig. 3C, when the vibration component generated in the moving direction is applied to the moving speed from the outer circumference to the inner circumference of the optical pickup, the pulse width t1 'for the mirror signal at this time is normal (i.e., no vibration). By narrowing the pulse width t1 of the state), the relationship of t1 to t1 'is established. Thereafter, the vibration of the lens occurs in the moving direction of the optical pickup (i.e., the tracking direction) as described above, and the vibration pickup is free from the vibration component at a predetermined time (a). In this case, the vibration component generated in the opposite direction to the moving direction of the optical pickup is applied, and the pulse width t1 when the pulse width t1 ″ for the mirror signal is normal (that is, without vibration) is applied. By expanding, the relationship of t1 "> t1 is established.

Therefore, at this time, the output waveform which is frequency / voltage converted and output by the frequency / voltage converter 12 shown in FIG. 1 is initially based on the potential level of the mirror signal when it is ideal as shown in FIG. As shown in FIG. 3 (C), as the vibration is generated inward, the pulse period is accelerated, and a potential level larger than the potential level for the mirror signal is output, and the vibration is generated at the peak of the non-vibration state (a). The period is slowed down so that the vibration component in the sine wave state is loaded on the basis of the potential level of the mirror signal.

Then, only the vibration component is extracted while passing through the high pass filter 13, and the waveform is output as shown in FIG.

Thereafter, the vibration component outputs the non-inverted amplified waveform as shown in FIG. 5 while passing through the non-inverted amplifier 20 connected to the output side of the high pass filter 13. The mirror signal in the case of the non-vibration state inputted to the non-inverting input terminal (+) by being input to the inverting input terminal (-) of the differential amplifier OP through the second switching unit 30 and the first switching unit 31. Since the potential level is differentially amplified from the reference potential level set by the resistor R2, a signal level larger than the reference charge level is first inputted during the inward vibration of the high frequency component of FIG. Level ". As a result, the NPN transistor Q2 of the NPN and PNP transistors Q1 and Q2 connected to the output terminal of the differential amplifier OP is "on", and the current direction thereof is the tracking coil TC from the power supply Vcc. ) To ground side.

Here, the tracking when the optical pickup moves from the outer circumference to the inner circumference when the current flows from the ground side to the power supply (-V _EE ) through the emitter terminal and the collector terminal of the PNP transistor Q2 via the tracking coil TC. In this case, since the current flows in the tracking coil TC in the direction opposite to the vibration direction, the vibration component is cancelled.

On the other hand, when the high speed long track jump is not performed, that is, when the optical pickup jumps to the point where the beam spot is out of the target track and linear control by the tracking error signal is possible, the first switching unit 31 is controlled by the microcomputer 50. ) Is switched to the tracking phase compensation circuit unit 40 and controlled according to the tracking error signal phase-compensated by the tracking phase compensation circuit unit 40.

Therefore, as can be seen from the above operation description, when the optical pickup proceeds from the inner circumference to the outer circumference or the high speed long track jump from the outer circumference to the inner circumference, the tracking servo is not turned off, but in the tracking direction during the long track jump without turning off the tracking servo. By detecting only the vibration component generated by the attenuation can be appropriately attenuated tracking can be accurate.

Claims (5)

An RF amplification / signal for amplifying the recording signal reading unit 10 for optically reading the data recorded on the optical recording medium and the recording data read by the recording signal reading unit 10 to perform predetermined signal processing Based on the tracking error signal phase-compensated by the tracking phase compensation circuit unit 40 and the tracking phase compensation circuit unit 40 for receiving a tracking error signal generated at the time of the tracking error and compensating for the phase thereof, Drive by a differential amplifier (OP) that differentially amplifies the level signal, the amplifying circuits (Q1, Q2) and amplifying servo control signals from the amplification circuits (Q1, Q2) that amplify the differential amplification signal of the differential amplifier (OP) An optical recording medium reproducing apparatus equipped with a tracking coil (TC) which performs a tracking control operation, wherein a frequency of a mirror signal is applied to a voltage by applying a frequency of a mirror signal among signals that are processed and output by the RF amplification / signal processing unit 11. A high pass filter 13 for extracting only the high frequency component which is an error component among the voltage signals from the frequency / voltage converting unit 12 and the high pass output from the high pass filter 13 Switching to either the inverted / non-inverted amplifiers 20 and 21 according to the control signals of the inverted / non-inverted amplifiers 20 and 21 and the microcomputer 50 for inverting or non-inverted amplification of the error signals of the components, respectively. According to the control signals of the second switching unit 30 and the microcomputer 50 to be switched, the first switching unit 31 switched to either the tracking phase compensation circuit unit 40 or the second switching unit 30 is further added. And a compensating / amplifying error component extracted from a mirror signal generated during a high speed long track jump so as to be output to a tracking coil TC. The method of claim 1, wherein the second switching unit 30 is a long tracking jump direction of the current optical pickup under the control of the microcomputer 50 is the forward tracking jump (that is, the optical pickup is moved from the inside to the outside) The track jump control of the optical recording medium reproducing system, characterized in that the inverted amplifier 20 is selected, and the non-inverted amplifier 21 is selected when the reverse tracking jump (that is, the optical pickup is from the outer to the inner). Device. According to claim 1, wherein the first switching unit 31 is the tracking phase compensation circuit unit 40 is selected in the case of not the normal playback mode or long crack jump under the control of the microcomputer 50, when the long track jump And a second switching unit (30) is selected in the track jump control apparatus of the optical recording medium reproducing system. 2. The differential amplifier OP of claim 1, wherein the differential amplifier OP selectively differentially compensates for a tracking error signal compensated by the tracking phase compensation circuit unit 40 or a mirror signal compensated for by the mirror signal error compensation unit with a reference level signal. And a track jump control apparatus for an optical recording medium reproducing system. The NPN transistor Q1 and the PNP transistor Q2 of claim 1, wherein the tracking coil TC has a vibration component of a mirror error signal input to the non-inverting input terminal (-) of the differential amplifier OP. Is selectively "on" so that a current flows in a direction opposite to the vibration direction.