JP2773132B2 - Tracking control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tracking control device for causing an information reproducing unit to follow a recording track in an optical disc player or the like.

2. Description of the Related Art Conventionally, there has been known a tracking control device in an optical disc player configured as shown in FIG.

In FIG. 4, when the tracking control device performs the track following operation, the switch 67 is closed, and the positional error between the scanning position of the information reproducing means 63 and the track on the recording disk 61 is detected by the track error detecting means 65. The control signal is applied to the actuator 64 via the adder 68 and the driving means 69 by the tracking control device 66, so that the information reproducing means 63 follows the target track on the recording disk 61.

On the other hand, at the time of the track jump operation, an acceleration pulse is generated by the jump pulse generating means 71 in accordance with the track jump command 73, and the switch 67 is opened before and after the acceleration pulse. The acceleration pulse generated by the jump pulse generator 71 is added to the adder 68.
Is applied to the actuator 64 through the driving means 69, and the information reproducing means 63 starts to accelerate to the target track. Subsequently, the comparator 70 detects that the track error signal, which is the output of the track error detection means 65, matches the specific reference level 72. At this timing, the deceleration pulse is generated by the jump pulse generation means 71, and the adder It is applied to the actuator 64 through 68 and the driving means 69. The jump to the target track is completed by closing the switch 67 again before or after the end of the deceleration pulse.
(See FIG. 5) Problems to be Solved by the Invention As shown in FIGS. 6b and 6c, the amplitude of the track error signal changes due to a change in the reflectivity of the disk, a change in the light beam output, and the like. Further, as shown in FIG. 6d, the center of the track error signal may be shifted due to an electrical offset, an optical offset, or the like of the tracking control device.

In such a case, in the above conventional example, since the acceleration pulse and the deceleration pulse are switched by detecting that the track error signal matches a specific reference level, as shown in FIG. As a result, the timing of switching between the acceleration pulse and the deceleration pulse changes, and overshoot and undershoot occur in the response of the actuator. In the worst case, it may not be possible to stably jump to the target track.

Further, in the above-described conventional example, since the acceleration pulse and the deceleration pulse are immediately switched upon detecting that the track error signal matches the specific reference level, it is necessary to detect that the track error signal matches the specific reference level. There is no time to switch between the acceleration and deceleration pulses.

Therefore, for example, as shown in FIG. 8, when the track error detecting means intermittently detects the positional deviation between the scanning position of the information reproducing means and the track on the recording disk, or when the track error detecting means detects the positional deviation of the information reproducing means. In the case where the position deviation between the position and the track on the recording disk is sampled and treated discretely, when the track error signal is compared with a specific reference level by the comparator, it is still at the reference level before point A in FIG. It can be seen that the signal has not reached the reference level and has passed the reference level only at the point B. However, the point C at which the positional deviation between the scanning position of the information reproducing means and the track on the recording disk coincided with the reference level has already been reached. If the acceleration pulse and the deceleration pulse are switched by detecting the point B, the response of the actuator will be overshot due to the delay of the time Td. In the worst case, it may not be possible to stably jump to the target track.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and when a change in the amplitude of a track error signal, an offset, or the like occurs, or when a track error detection unit intermittently intervenes between the scanning position of the information reproduction unit and the recording disk. When detecting a positional deviation from a track, or when a track error detecting unit discretely samples and treats a positional deviation between a scanning position of an information reproducing unit and a track on a recording disk and jumps to a target track stably. It is an object of the present invention to provide a tracking control device which can perform the tracking.

Means for Solving the Problems In order to solve the above problems, the tracking control device of the present invention provides a tracking error detection device in which a signal of a track error detection unit in which an electric offset or an optical offset is superimposed after an acceleration pulse is applied to an actuator is maximized or A peak timing detecting means for detecting a timing when a point near the minimum point is detected; an accelerating pulse terminating means for terminating the accelerating pulse a predetermined time after the detection of the peak timing based on a detection signal from the peak timing detecting means; A deceleration pulse generating means for generating a deceleration pulse a predetermined time after the detection of the peak timing based on a detection signal from the timing detection means.

Effect of the Invention According to the present invention, when the track error signal on which the electrical offset or the optical offset, which is the output of the track error detecting means, is superimposed near the maximum or minimum point, after the acceleration pulse is applied to the actuator, The timing of the track error signal is detected by peak timing detection means by determining whether the track error signal reaches a predetermined level, but by checking the increase or decrease of the track error signal, and after a predetermined time in accordance with the peak timing, Since the acceleration pulse is terminated by the acceleration pulse ending means or the deceleration pulse is generated by the deceleration pulse generation means, the track jump can be performed stably without being affected by the change in the amplitude of the track error signal or the offset. it can.

Also, since there is a time margin between the detection of the peak timing and the termination of the acceleration pulse by the acceleration pulse termination unit or the generation of the deceleration pulse by the deceleration pulse generation unit, the track error detection unit intermittently outputs information. When detecting the positional deviation between the scanning position of the reproducing means and the track on the recording disk, or the track error detecting means samples and treats the positional deviation between the scanning position of the information reproducing means and the track on the recording disk discretely. For example, even when a time delay exists in detecting the peak timing, the delay can be corrected.

Embodiment First, an embodiment in which the present invention is applied to an optical disk player will be described.

This apparatus is affected by a change in the amplitude of the track error signal due to a change in the reflectivity of the recording disk, a change in the output of the light beam, or the like, or an offset of the track error signal caused by an electrical offset, an optical offset, or the like of the tracking control device. This is a tracking control device capable of performing a stable track jump without being affected.

When the track error detecting means intermittently detects a positional deviation between the scanning position of the information reproducing means and the track on the recording disk, or when the track error detecting means detects the positional deviation between the scanning position of the information reproducing means and the track on the recording disk. In this case, a stable track jump can be performed even in the case where the position deviation is sampled and handled discretely.

 Hereinafter, a specific description will be given with reference to the drawings.

FIG. 1 is a configuration diagram of the tracking control device of the first embodiment. In FIG. 1, when the tracking control device is operating to follow the track, the switch 7 is turned on.
Is closed, the positional deviation between the information reproducing means 3 and the track on the recording disk 1 is detected by the track error detecting means 5, and the control signal is sent from the tracking control device 6 to the actuator 4 through the adder 8 and the driving means 9. The application causes the information reproducing means to follow the target track on the recording disk 1.

On the other hand, at the time of the track jump operation, an acceleration pulse is generated by the jump pulse generating means 13 in response to the track jump command 14, and the switch 7 is opened before and after the acceleration pulse. The acceleration pulse generated by the jump pulse generating means 13 is applied to the actuator 4 through the adder 8 and the driving means 9, and the information reproducing means 3 starts to accelerate to the target track. After the application of the acceleration pulse, the peak timing detecting means 10 detects the timing when the track error signal on which the electrical offset or the optical offset output from the track error detecting means 5 is superimposed is near the maximum or minimum point. According to the detection timing, after a predetermined time, the acceleration pulse ending means 11 sends an acceleration pulse end command to the jump pulse generation means 13, and the acceleration pulse ends.

Further, in response to a peak timing detection signal from the peak timing detection means, after a predetermined time, a deceleration pulse generation command is sent from the deceleration pulse generation means 12 to the jump pulse generation means 13 and deceleration is performed through the adder 8 and the drive means 9. A pulse is applied to the actuator 4 and the information reproducing means 3
Slows down. The track jump operation is completed by closing the switch 7 again before or after the end of the deceleration pulse. (See FIG. 9) Next, FIG. 10 shows a configuration example of the peak timing detecting means. In FIG. 10, the input track error signal is divided into two parts, one for the direct comparator 82 and the other for the delay means.
After being delayed at 81, it is sent to the comparator 82. The peak timing is detected by the comparator 82 determining that the difference between the two levels is equal to or less than a specific value.

When the track error detecting means 5 intermittently detects the positional deviation between the scanning position of the information reproducing means 3 and the track on the recording disk 1, or when the track error detecting means 5 detects the positional deviation between the scanning position of the information reproducing means 3 and the recording position. In the case where the position deviation from the track on the disk 1 is sampled and handled discretely, the output of the track error detecting means 5 has a form as shown in FIG. 11, for example. The peak timing detecting means in this case may be, for example, as follows. Assuming that the track error signals at times t _n−1 , t _n and t _{n + 1} are TE _n−1 , TE _n and TE _{n + 1} , TE _n ≧ TE _n−1 and TE _n > TE _{n + 1} or It is determined that TE _n ≦ TE _n−1 and TE _n > TE _{n + 1,} and the time point t _n at that time is set as the peak timing tpeak.

_{Alternatively, t n-1 ~t n ~t} n + 1 substantially equal interval, t _n-1
Since the moving speed of the actuator 4 between the t _n is substantially constant from, for _{example, tpeak = t n + (t} n + 1 -t n-1) · (TE n + 1 -TE n-1) / ( TE _n
−TE _n-1 ) may be used to correct the peak timing. In addition,
It goes without saying that a means other than the above example may be used as the peak timing detecting means 10.

With the above configuration, when a change in the amplitude of the track error signal, an offset, or the like occurs, or when the track error detecting means intermittently detects a positional deviation between the scanning position of the information reproducing means and the track on the recording disk, Also, a tracking control device capable of performing a stable track jump even when the track error detecting means samples and treats the position deviation between the scanning position of the information reproducing means and the track on the recording disk in a discrete manner is obtained.

FIG. 2 shows a configuration diagram of the second embodiment, which will be described.
As shown in FIG. 2, in the second embodiment, at least the acceleration pulse generation means or the deceleration pulse generation means in the first embodiment is a delay unit for a fixed time, and the reflectance of the recording disk is reduced. Effects due to changes in the amplitude of the track error signal due to changes in
Another object of the present invention is to provide a tracking control device capable of performing a stable track jump without being affected by the occurrence of an offset of a track error signal due to an electrical offset or an optical offset of the tracking control device.

When the track error detecting means intermittently detects a positional deviation between the scanning position of the information reproducing means and the track on the recording disk, or when the track error detecting means detects the positional deviation between the scanning position of the information reproducing means and the track on the recording disk. In this case, a stable track jump can be performed even in the case where the position deviation is sampled and handled discretely.

Hereinafter, a specific description will be given with reference to the drawings. In FIG. 2, when the tracking control device performs the track following operation, the switch 27 is closed, and the positional deviation between the information reproducing means 23 and the track on the recording disk 21 is detected by the track error detecting means 25. Tracking control device
The control signal is applied by 26 to the actuator 24 through the adder 28 and the driving means 29 so that the information reproducing means follows the target track control device on the recording disk 21.

On the other hand, at the time of the track jump operation, an acceleration pulse is generated by the jump pulse generating means 33 in response to the track jump command 34, and the switch 27 is opened before and after the acceleration pulse. The acceleration pulse generated by the jump pulse generating means 33 is applied to the actuator 24 through the adder 28 and the driving means 29, and the information reproducing means 23 starts to accelerate to the target track. After the acceleration pulse is applied, the timing when the track error signal on which the electrical offset or the optical offset output from the track error detecting means 25 is superimposed becomes near the maximum or minimum point is detected by the peak timing detection means 30. The peak timing detection signal is delayed for a predetermined time by the delay unit 31, and the signal is sent to the jump pulse generation means 33 as an acceleration pulse end command, and the acceleration pulse ends.

Further, the peak timing signal from the peak timing detecting means 30 is delayed for a predetermined time by the delay unit 32, and the signal is used as a deceleration pulse generating command as a jump pulse generating means.
33, a deceleration pulse is applied to the actuator 24 through the adder 28 and the driving means 29, and the information reproducing means 23 is decelerated. The track jump operation is completed by closing the switch 27 again before or after the end of the deceleration pulse. (No.
Note that the delay times of the delay unit 31 and the delay unit 33 may be the same or different.

The configuration method of the peak timing detection means is the same as that of
Is the same as that shown in FIG.

With the above configuration, when a change in the amplitude of the track error signal, an offset, or the like occurs, or when the track error detecting means intermittently detects a positional deviation between the scanning position of the information reproducing means and the track on the recording disk, Also, a tracking control device capable of performing a stable track jump even when the track error detecting means samples and treats the position deviation between the scanning position of the information reproducing means and the track on the recording disk in a discrete manner is obtained.

Next, a configuration of the third embodiment is shown in FIG. 3 and will be described. As shown in FIG. 3, in this embodiment, the tracking control device of the first embodiment has a measurement for measuring a time from when an acceleration pulse is generated until a peak timing is detected by a peak timing detecting means. Means, the influence of a change in the amplitude of the track error signal due to a change in the reflectivity of the recording disk or a change in the light beam output, or a change in the track error signal due to an electrical offset or an optical offset of the tracking control device. An object of the present invention is to provide a tracking control device capable of performing a stable track jump without being affected by the occurrence of an offset.

When the track error detecting means intermittently detects a positional deviation between the scanning position of the information reproducing means and the track on the recording disk, or when the track error detecting means detects the positional deviation between the scanning position of the information reproducing means and the track on the recording disk. In this case, a stable track jump can be performed even in the case where the position deviation is sampled and handled discretely.

Further, even with the influence of disturbance such as eccentricity of the recording disk, the end timing of the acceleration pulse and the generation timing of the deceleration pulse are adjusted to enable a stable track jump.

Hereinafter, a specific description will be given with reference to the drawings. In FIG. 3, when the tracking control device performs a track following operation, the switch 47 is closed, and the positional deviation between the information reproducing means 43 and the track on the recording disk 41 is detected by the track error detecting means 45. The control signal is supplied to the actuator through the adder 48 and the driving means 49 by the actuator 46.
44, the information reproducing means 43 is applied to the recording disk.
Follow the target track on 41.

On the other hand, at the time of the track jump operation, an acceleration pulse is generated by the jump pulse generating means 53 according to the track jump command 55, and the switch 47 is opened at about the same time. The acceleration pulse generated by the jump pulse generating means 53 is applied to the actuator 44 through the adder 48 and the driving means 49, and the information reproducing means 43 starts to accelerate to the target track. After the acceleration pulse is applied, the timing when the track error signal on which the electrical offset or the optical offset, which is the output of the track error detection means 45, is superimposed is near the maximum or minimum point is detected by the peak timing detection means 50. The time from when the acceleration pulse is generated by the measuring means 54 to when the peak timing is detected is measured.

Here, when the time measured by the measuring means 54 is shorter than when there is no disturbance such as eccentricity of the recording disk, the relative speed of the information reproducing means 43 with respect to the track position on the recording disk 41 is recorded. It becomes larger due to the influence of disturbance due to eccentricity of the disk. Therefore, in order to make a stable track jump, the timing at which the acceleration pulse ending means 51 receives the peak timing detection signal and then issues the acceleration ending command is advanced according to the time measured by the measuring means 54 as compared with the case where there is no disturbance. Then, the acceleration pulse is sent to the jump pulse generating means 53, and the acceleration pulse ends.

Subsequently, the deceleration pulse generation unit 52 receives the peak timing detection signal from the case where there is no disturbance in accordance with the time measured by the measurement unit 54, so that the timing to start the deceleration pulse is earlier, and A deceleration pulse generation command is sent to the jump pulse generation means 53 so as to delay the timing of terminating the operation. The deceleration pulse is applied to the actuator 44 through the adder 48 and the driving means 49, and the information reproducing means 43 is decelerated. The track jump operation is completed by closing the switch 47 again before or after the end of the deceleration pulse.

Conversely, when the time measured by the measuring means 54 is shorter than when there is no disturbance such as eccentricity of the recording disk, the relative speed of the information reproducing means 43 with respect to the track position on the recording disk is reduced. Due to the influence of disturbance such as eccentricity. Therefore, in order to make a stable track jump, the timing at which the acceleration pulse ending means 51 receives the peak timing detection signal and then issues the acceleration ending command is delayed according to the time measured by the measuring means 54 as compared with the case where there is no disturbance. Jump pulse generating means 53
And the acceleration pulse ends.

Subsequently, the deceleration pulse generation unit 52 receives the peak timing detection signal from the case where there is no disturbance in accordance with the time measured by the measurement unit 54, so that the timing to start the deceleration pulse is delayed, and A deceleration pulse generation command is sent to the jump pulse generation means 53 so that the timing for ending the processing is advanced, and a deceleration pulse is applied to the actuator 44 through the adder 48 and the driving means 49, so that the information reproducing means 43 decelerates. The track jump operation is completed by closing the switch 47 again before or after the end of the deceleration pulse. (See FIG. 13.) The configuration of the peak timing detecting means is the same as that shown in the first embodiment.

With the above configuration, when a change in the amplitude of the track error signal, an offset, or the like occurs, or when the track error detecting means intermittently detects a positional deviation between the scanning position of the information reproducing means and the track on the recording disk, The track jump can be performed stably even when the track error detecting means samples and discretely handles the positional deviation between the scanning position of the information reproducing means and the track on the recording disk, or when disturbance due to eccentricity of the recording disk is applied. And a tracking control device that can perform the tracking.

Effects of the Invention As described above, according to the present invention, when a change in the amplitude of a track error signal, an offset, or the like occurs, or when the track error detecting means intermittently changes the scanning position of the information reproducing means and the track on the recording disk, The track jump can be performed stably even when detecting a positional deviation from the data, or when the track error detecting means samples and discretely handles the positional deviation between the scanning position of the information reproducing means and the track on the recording disk. A tracking control device that can be obtained.

In addition, it is possible to obtain a tracking control device capable of performing a stable track jump even when disturbance due to eccentricity of the recording disk or the like is applied.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a tracking control device according to a first embodiment of the present invention, FIG. 2 is a block diagram showing a configuration of a tracking control device according to a second embodiment, and FIG. FIG. 4 is a block diagram showing the configuration of a conventional tracking control device, and FIG.
FIG. 6 is a timing chart showing the operation of the conventional example.
FIG. 7 is a waveform diagram of the track error signal, FIG. 7 is a waveform diagram showing the relationship between the waveform of the track error signal and the timing of the jump pulse, FIG. 8 is a waveform diagram showing the output of the track error detecting means, and FIG. FIG. 10 is a block diagram showing the configuration of the peak timing detecting means, FIG. 11 is a waveform diagram for explaining the operation of the peak timing detecting means, and FIG. FIG. 13 is a timing chart showing the operation of each part of the third embodiment, and FIG. 13 is a timing chart showing the operation of each part of the third embodiment. 1,21,41,61 ... recording disk, 2,22,42,62 ... disk motor, 3,23,43,63 ... information reproducing means, 4,24,44,64 ...
Actuator, 5, 25, 45, 65… track error detecting means, 6, 26, 46, 66… tracking control device, 7, 27, 47, 67
…… Switch, 8,28,48,68 …… Adder, 9,29,49,69 ……
Driving means, 10, 30, 50 ... peak timing detecting means, 1
1,51, acceleration pulse ending means, 12,52 deceleration pulse generation means, 13,33,53,71 jump pulse generation means, 14,
34,55,73 …… Track jump command, 31 …… Delay device, 32
... Delay device, 54 measurement means, 70 comparator, 72 reference level, 81 delay means, 82 comparator, 83 track error signal.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 21/08 G11B 7/085

Claims (4)

(57) [Claims] 1. An information reproducing means for reproducing information recorded by scanning on a recording medium, an actuator for driving the information reproducing means, and a positional deviation between a scanning position of the information reproducing means and a recording track. Track error detecting means for detecting, and tracking control means for controlling the actuator so that the information reproducing means follows the recording track in accordance with an output signal of the track error detecting means; And fine movement means for applying a jump pulse including a deceleration pulse and causing the information reproducing means to perform a track jump from the track currently following to another track, and after the acceleration pulse is applied to the actuator. The signal of the track error detecting means is near the maximum or minimum point Timing detection means for detecting the timing of the above, acceleration pulse termination means for terminating the acceleration pulse a predetermined time after the detection of the peak timing based on the peak timing detection signal from the peak timing detection means, the peak timing detection means And a deceleration pulse generating means for generating the deceleration pulse after a predetermined time from the detection of the peak timing based on the detection signal of the peak timing. The output signal of the track error detection means has an electrical offset or an optical offset. A tracking control device characterized by being superimposed. 2. The tracking control device according to claim 1, wherein the acceleration pulse ending means terminates the acceleration pulse a predetermined time after the peak timing detection signal is applied from the peak timing detection means. 3. The tracking control device according to claim 1, wherein the deceleration pulse generating means generates the deceleration pulse a predetermined time after the peak timing detection signal is applied from the peak timing detection means. . And measuring means for measuring a time from when the acceleration pulse is applied to the actuator to when the peak timing is detected by the peak timing detecting means,
At least the acceleration pulse ending means varies the timing of terminating the acceleration pulse according to the measurement result of the measurement means, or the deceleration pulse generation means varies the timing of generating the deceleration pulse according to the measurement result of the measurement means. The tracking control device according to claim 1, 2 or 3, wherein