JPH0457218A - Recording disk reproducing device - Google Patents

Abstract

PURPOSE:To make a screen change intimate so as to easily watch the screen at the time of trick play by making a control circuit decide what time a pickup jumping command should be issued to a jump circuit with a signal to be generated by a frequency divider circuit. CONSTITUTION:Time is detected by a detector circuit 41 when a driving voltage (an output of a motor driving circuit) of a spindle motor 34 becomes zero, and an output of the frequency divider circuit 42 to be generated in timing with this time is inputted to the control circuit 37, and a jumping operation is performed by an output of the control circuit 37, so that a control error is suppressed to a min. even when the spindle motor 34 is rotated by inertia of a recording disk during jumping, and hence the pull-in time of a control upon the spindle motor 34 after jumping can be reduced. Consequently, the time until the next screen is stored in a field memory 25 is shortened, and the screen change is intimate, so that the screen is easily watched even at the time of trick play.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a recording disc playback device such as a video disc player that enables variable speed playback.

2. Description of the Related Art In recent years, recording disk playback devices have become popular as video disk players and the like. In particular, in these recording disk playback devices, as the prices of digital memories have fallen in recent years, field memory has been applied to enable double-speed playback and low-speed playback on recording disks using a constant linear velocity force, which was previously impossible. Trick plays such as this have been realized.

This kind of trick play involves tracing the pickup to the track to reproduce information, writing the reproduced image to field memory, and writing 1 to field memory.
This is performed by repeatedly moving the pickup in the radial direction of the recording disk (hereinafter referred to as "jumping") while reading out the captured image. Therefore, the time from the end of the jump until the information is accurately reproduced affects the switching time of output images during these trick plays.

In the future, it is desired to introduce a recording disk reproducing apparatus that shortens the time from the end of this jump until information is accurately reproduced, and that shortens the switching time of output images during trick play.

Hereinafter, an example of the above-mentioned conventional recording disk reproducing apparatus will be explained with reference to the drawings.

FIG. 7 is a block diagram showing the configuration of a conventional recording disk reproducing apparatus. In the figure, 1 is the recording disk, 2 is the recording disk 1
3 is a video signal demodulation circuit; 4 is a time axis correction circuit connected to the rear stage of the video signal demodulation circuit 3; 5 is a field for storing and outputting the output of the time axis correction circuit 4. 6 is a first switch provided after the field memory 5, 7 is a terminal,
Reference numeral 8 indicates a horizontal synchronization separation circuit connected to the subsequent stage of the video signal demodulation circuit 3, reference numeral 9 indicates a reference synchronization generation circuit that generates a reference synchronization signal, and reference numeral 10 indicates an input of the outputs of the horizontal synchronization separation circuit 8 and reference synchronization generation circuit 9. A phase comparator 11 is a loop filter that delays the phase of the output of the phase comparator 1Q by 90 degrees.
2 is a second switch provided after the loop filter 11, 13 is a motor drive circuit provided after the second switch 12, 14 is a spindle motor that rotates the storage disk 1, and 15 is an output to the pickup 2. 16 is a jump circuit that issues a pickup 2 heshyamp command; 17 is a field memory 5.
This is a control circuit that controls the first switch 6, the tracking servo circuit 16, and the jump circuit 16.

In FIG. 7, a pickup 2 reads signals recorded on tracks of a recording disk 1 and converts them into electrical signals. The output of the pickup 2 is demodulated into a composite video signal by a video signal demodulation circuit 3.

The output of the phase comparator 10 is input to the loop filter 11, and the output of the loop filter 11 is input to the second switch 12.
The output of the motor drive circuit 13 rotates the spindle motor 14 . That is, the spindle motor 1 is adjusted so that the phase of the signal generated by the reference synchronization generation circuit 9 and the output of the horizontal synchronization separation circuit 8 matches.
4 rotation speed is controlled. Now, if the oscillation frequency of the reference synchronization generation circuit 9 is set to the horizontal scanning frequency of the regular video signal, the spindle motor 14 will be controlled by the video signal demodulation circuit 3.
is controlled so that the output is at the frequency of the regular video signal. However, the output of the video signal demodulation circuit 3 contains high-frequency jitter components that cannot be sufficiently removed by controlling the spindle motor 14 due to the eccentricity of the recording disk 1, etc., and cannot be reproduced as is on a television receiver. . Therefore, the time axis correction circuit 4 is used to remove the jitter component. The time axis correction circuit 4 removes high frequency jitter components, and the reproduced signal, which has become a regular video signal, is input to the first switch 6 and the field memory 5. The first switch 6 connects the output of the time axis correction circuit 4,
The output of field memory 5 is selected and output to terminal 7. The output of terminal 7 is that ``!,''! It can be played on a television receiver.

During normal playback, the control circuit 1 issues a servo loop close command to the tracking servo circuit 15 to cause the pickup 2 to trace the track on the recording disk 1. Second
Connect the switch 12 to the a side to connect the spindle motor 14.
set to the normal rotation speed, and at the same time connect the first switch 6 to the a side, output the output of the time axis correction circuit 4 to the terminal 7, and send the recorded information of the recording disk reproduced to the normal video signal to the terminal. Output to 7.

During trick play, the control circuit 17 issues a servo loop closing command to the tracking servo circuit 15,
The pickup 2 is traced to the track of the recording disk 1. Connect the second switch 12 to the a side to set the spindle motor 14 to the normal rotation speed, store the output of the time axis correction circuit 4 in the field memory 5, connect the first switch 6 to the b side, and set the spindle motor 14 to the normal rotation speed. The output of memory 5 is output to the terminal. Next, the control circuit 17 issues a servo loop open command to the tracking servo circuit 16, and simultaneously issues a jump command to the jump circuit 16. When receiving a jump command, the jump circuit 16 moves the pickup 2 in the radial direction of the recording disk 1 for a certain period of time to complete the jump operation. When the jump operation is completed, the control circuit 17 again applies a servo loop closing command to the tracking servo circuit 15 to cause the pickup 2 to trace the track on the recording disk 1. During the jump operation, the output of pickup 2 is
Since it is not a regular signal, the output of the horizontal synchronization separation circuit 8 during this time is unreliable, and the spindle motor 14 cannot be controlled thereby. Therefore, during this period, the control circuit 1T sets the second switch 12 to the d side and rotates the spindle motor 14 due to inertia.

After the jump is completed, the tracking servo is set, and when the spindle motor 14 reaches the normal rotation speed, the output of the time axis correction circuit 4 is stored in the field memory 5 again.

By repeating the above actions, you can perform a trick play. FIG. 8 is a flowchart showing the operation of the control circuit 17 during trick play in a conventional recording disk reproducing apparatus.

FIG. 9 shows the movement of a pickup during trick play in a conventional recording disk reproducing apparatus. As shown in the figure, the jump operation shortens the playback time axis and enables high-speed playback. You can change the playback speed by changing the number of jump tracks and direction.

FIG. 1Q shows input signals to the motor drive circuit 13 during playback and trick play in a conventional recording disk playback device.

A change in this signal directly corresponds to a change in the torque generated by the spindle motor 14.

During normal playback, a signal that cancels out slight lateral and windage losses and a signal that cancels out phase errors due to eccentricity of the recording disk 1 are combined to form a sine wave signal as shown in the figure. During trick play, the second switch 12 is set to the d side at the timing of a jump, and the spindle motor 14 rotates due to inertia, so the input signal during that time becomes 0. After the jump is completed, the second switch 12 is turned to the a side again, and the waveform of the input signal gradually approaches a sine wave signal.

Problems to be Solved by the Invention However, in a recording disk reproducing device having such a configuration,
During the jump, the spindle motor rotates due to the inertia of the recording disk, resulting in a control error, and it takes time to control the spindle motor after the jump. Unfortunately, it takes time to store the next playback screen in the field memory, and the screens change sparsely, making it difficult to see the screen during trick plays.

In view of the above-mentioned problems, the present invention provides a recording disc playback device which can shorten the control pull-in time of a spindle motor after a jump, switches screens closely, and makes the screen easy to see even during trick play.

Means for Solving the Problems In order to solve the above problems, the recording disk reproducing apparatus of the present invention reads and reads signals recorded on tracks of a recording disk.
A pickup that converts into an electrical signal, a motor that rotates a recording disk, a jump circuit that drives the pickup to move the pickup from the track it is tracing to a different track, and a synchronization signal recorded on the recording disk. a phase comparator that compares the phase of the recording disk with the phase of a reference synchronization signal that is a reference for controlling the rotation of the recording disk; a drive circuit that receives the output of the phase comparator and generates a signal that rotates the motor; The control circuit includes a detection circuit that detects a position where the polarity of the output voltage of the circuit is reversed, and a frequency divider circuit that generates a signal at the detection position, and the control circuit causes the jump circuit to receive the pick-up circuit according to the signal generated by the frequency divider circuit. The method is characterized in that it determines the time at which a jump is commanded.

Function: In the present invention, the detection circuit predicts the time when the drive voltage of the motor becomes zero, and the pickup is caused to jump at that time, so even if the motor is rotated by the inertia of the recording disk during the jump, the control remains unchanged. It is possible to reduce the error and reduce the motor control pull-in time after a jump.

Embodiment Hereinafter, a recording disk reproducing apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a recording disk reproducing apparatus according to an embodiment of the present invention. In the figure, 21 is a recording disc;
22 is a pickup for reading the pig recorded on the recording disk 21, 23 is a video signal demodulation circuit provided after the pickup 2, 24 is a time axis correction circuit provided after the video signal demodulation circuit 23, and 25 is a time correction circuit. A field memory 26 is connected to the rear stage of the axis correction circuit 24, and 27 is a first switch provided at the rear stage of the field memory 25.
28 is a horizontal synchronization separation circuit provided after the video signal demodulation circuit 23; 29 is a reference synchronization generation circuit that generates a base synchronization signal; 30 is a terminal provided after the first switch 26; A phase comparator to which the outputs of the horizontal synchronization separation circuit 28 and the reference synchronization generation circuit 29 are input; 31 is a loop filter that delays the phase of the output of the phase comparator 3o by 90 degrees;
32 is a second switch provided after the loop filter 31; 33 is a motor drive circuit connected after the second switch 32; 34 is a spindle motor that rotates the recording disk 21; and 35 is a control for the pickup 22. A tracking servo circuit 36 is a jump circuit that makes the pickup 2 jump.

37 is a field memory 25. First switch 26, second switch 32. A control circuit that controls the tracking servo circuit 35 and the jump circuit 36; 38 is the recording disk 2;
1, 39 is a photointerrupter for detecting the rotation speed of slit disk 38, 40 is a waveform shaping circuit for shaping the output waveform of photoincrement free 39, and 41 is a waveform shaping circuit 4Q and a phase comparator 30. A detection circuit 42 is provided at a subsequent stage to detect the zero position of the motor drive; 42 is a frequency dividing circuit provided at a subsequent stage of the detection circuit 41;
3 is a third circuit connected between the detection circuit 41 and the frequency dividing circuit 42.
It is a switch.

FIG. 2 is a block diagram of a detection circuit for detecting the zero position of motor drive in a recording disk reproducing apparatus according to an embodiment of the present invention. In the figure, 51 is a first AND gate into which the polarity of the phase comparator is input, 62 is an inverter connected in parallel to the first AND gate 51, and 53 is a second AND gate provided after the inverter 52. 54 is an up counter into which the output of the first AND gate 51 is input; 55 is a station circuit that converts the output of the up counter 54 into %; 56 is a falling gate connected in parallel with the first AND gate 51; 57 is a subtracter provided after the % circuit 55; 68 is a second AND gate 53. A down counter 59 to which the outputs of the subtracter 57 and the falling edge detection circuit 56 are input is a terminal connected to the downstream stage of the down counter 58.

The operation of the recording disk reproducing apparatus of the present invention constructed as described above will be described below.

In FIG. 1, a pickup 22 reads signals recorded on tracks of a recording disk 21 and converts them into electrical signals.The output of the pickup 22 is demodulated into a composite video signal by a video signal demodulation circuit 23.

The output of the phase comparator 30 is input to the loop filter 31, and the pressure of the loop filter 31 is input to the second switch 32.
The signal is input to the motor drive circuit 33 through the motor drive circuit 33, and the spindle motor 34 is rotated by the output of the motor drive circuit 33. That is, the rotation speed of the spindle motor 34 is controlled so that the signal generated by the reference synchronization generation circuit 29 and the output of the horizontal synchronization separation circuit 28 are in phase. Now, reference synchronization generation circuit 2
If the oscillation frequency of 9 is set to the horizontal scanning frequency of the regular video signal, the spindle motor 34 is controlled so that the output of the video signal demodulation circuit 23 becomes the frequency of the regular video signal. However, the output of the video signal demodulation circuit 23 contains high-frequency jitter components that cannot be sufficiently removed by controlling the spindle motor 34 alone due to eccentricity of the recording disk 21, etc. Unable to play. Therefore, the time base correction circuit 24 is used to remove the jitter component. Time axis correction circuit 2
At step 4, the high frequency jitter component is removed and the reproduced signal, which has become a regular video signal, is input to the first switch 26 and the field memory 25.

The first switch 26 connects the output of the time axis correction circuit 24,
The output of the field memory 25 is selected and outputted to the terminal 27. The output of the terminal 27 can be reproduced as is on a television receiver.

The Nurisoto disk 38 has 60 Nulits, and when the spindle motor 34 rotates, the light from the photointerrupter 39 is blocked or passed depending on the rotation angle. If the output of the photointerrupter 39 is shaped and counted by the waveform shaping circuit 4o, the amount of rotation of the spindle motor 34 can be obtained.The output of the waveform shaping circuit 4o is sent to the motor drive zero position detection circuit 41 and the frequency dividing circuit 42.

The operation of the motor drive zero position detection circuit 41 will be explained using FIGS. 2 and 3. FIG. 3 is a final diagram illustrating the operation of a recording disk reproducing apparatus according to an embodiment of the present invention.

The polarity output of the phase comparator 30 is as shown in FIG.
It outputs Hi when the phase of the reproduction synchronization signal is ahead of the phase of the reference synchronization signal, and outputs Lo when it is behind. Since there is a 90° phase difference between the output of the phase comparator 3o and the output of the motor drive circuit 33 due to the loop filter 31, the peak position of the phase error in Fig. 3 is the time when the motor drive signal becomes zero. It is.

When 3Q pulses in the output of the waveform shaping circuit 4o correspond to % rotation, if the number of output pulses of the waveform shaping circuit 40 during the period in which the polarity output of the phase comparator 30 is Hi is A, then the polarity output of the phase comparator 30 is The time from the time of inversion from Hi to LO to the peak position of the phase error is 30-A/2 in terms of the number of output pulses of the waveform shaping circuit 4o.

FIG. 2 shows a circuit that performs this calculation. Second
In the figure, the output of the first AND gate 51 is input to the waveform shaping circuit 40, which is input during the period when the phase comparison polarity output is Hi.
This is the output of This is counted by an up counter and set as A. When the output is inputted by the 34 circuit 55 and subtracted by 30 by the subtracter 57, the output of the subtracter 57 becomes 30-A/2.

This value is loaded into the down counter 58 at the time when the polarity output of the phase comparator 30 is reversed from Hi to Lo. Second A
The output of the ND gate 53 is the output of the waveform shaping circuit 4° to which the polarity output of the phase comparator 3o is input during the LO period. When this is counted by the down counter 58, the time when the polarity output of the phase comparator 3o becomes zero coincides with the peak position of the phase error described above.

During normal playback, the control circuit 37 issues a servo loop close command to the tracking servo circuit 35 to cause the pickup 22 to trace the track on the recording disk 21.

The second switch 32 is connected to the C side to set the spindle motor 34 to the normal rotation speed, and at the same time, the first switch 26 is connected to the C side.
is connected to the a side, and the output of the time axis correction circuit 24 is connected to the terminal 27.
The recorded information on the recording disc reproduced into a regular video signal is outputted to the terminal 27.

During trick play, the control circuit 37 issues a servo loop closing command to the tracking servo circuit 35 in advance to trace the pickup 22 to the track of the recording disk 21, and connects the second switch 32 to the C side. The spindle motor 34 is set to the normal rotation speed, the third switch 43 is set to the e side, and the motor drive zero position detection circuit 41 is turned on.
The frequency dividing circuit 42 is reset by the output of , and then the switch 43 of the tube 3 is set to the f side. The frequency dividing circuit 42 counts the output of the waveform shaping circuit 40 and generates a pulse every 30 times.

That is, the frequency dividing circuit 42 is reset at the time when the motor drive signal becomes zero, and outputs a pulse every time the spindle motor 34 rotates by %, so the time at which this pulse is output is the time when the motor drive signal becomes zero. The time has come.

The control circuit 37 issues a servo loop closing command to the tracking servo circuit 35 to move the pickup 22 to the recording disk 2.
Trace to track 1. Connect the second switch 32 to the C side to set the spindle motor 34 to the normal rotation speed, and transfer the output of the time axis correction circuit 24 to the field memory 25.
The first switch 26 is connected to the b side, and the output of the field memory 26 is outputted to the terminal 27.

Next, the control circuit 37 waits for the frequency dividing circuit 42 to output a pulse. When the control circuit detects the pulse of the frequency dividing circuit 42, it issues a servo loop open command to the tracking servo circuit 35, and simultaneously issues a jump command to the jump circuit 36. When receiving a jump command, the jump circuit 36 moves the pickup 22 in the radial direction of the recording disk 21 for a certain period of time to complete the jump operation. When the jump operation is completed, the control circuit 37 issues a servo loop closing command to the tracking servo circuit 35 again, and the pickup 22
Trace the data to the track of recording disk 21. During the jump operation, the output of the pickup 22 does not become a regular signal, so the output of the horizontal sync separation circuit 28 during the jump operation is
It is unreliable, and the Nuhindle mall 34 cannot be controlled thereby. Therefore, during this period, the control circuit 37 sets the second switch 32 to the d side and rotates the system spindle motor 34 by inertia. After the jump, the tracking servo is set and the spindle motor 3
4 reaches the normal rotational speed, the output of the time axis correction circuit 24 is stored in the field memory 25 again.

By repeating the above actions, you can perform a trick play. FIG. 4 is a flowchart showing the operation of the control circuit 37 during trick play of the recording disk reproducing apparatus according to one embodiment of the present invention.

FIG. 5 shows the movement of the pickup during trick play in the recording disk reproducing apparatus according to an embodiment of the present invention. As shown in the figure, the jump operation shortens the playback time axis and enables high-speed playback. You can also change the playback speed by changing the number of jump tracks and direction.

FIG. 6 shows input signals to the motor drive circuit 33 during playback and trick play of the recording disk playback apparatus according to an embodiment of the present invention. A change in this signal corresponds to a change in the torque generated in the spindle motor 34. During normal playback, there is a signal that cancels out slight axial damage and windage damage, and a signal that
The signals that cancel out the phase error due to eccentricity are combined to form a sine wave signal as shown in the figure. During a trick play, the second switch 32 is set to the d side at the timing of a jump, and the spindle motor 34 rotates due to inertia.
The value of the sine wave signal during that time is O.

When the second switch 32 is set to the C side again after the jump, the spindle motor 3
An error occurs because the torque that should be generated in step 4 is not generated, but since the output of the original motor drive circuit 33 during jumping is also mostly ○, the error is small and the time to complete the pull-in is significantly reduced. It is shortened to .

As described above, in the recording disk reproducing apparatus according to the embodiment of the present invention, the detection circuit 41 detects the time when the drive voltage of the spindle motor 34 (output of the motor drive circuit) becomes zero, and the signal is generated in accordance with that time. By inputting the output of the frequency dividing circuit 42 into the control circuit 37 and causing the jump operation to be performed using the output of the control circuit 37, the control error can be reduced even if the spindle motor 34 is rotated by the inertia of the recording disk during the jump. The control pull-in time for the spindle motor 34 after the presser foot and jump can be reduced. Therefore, the time required to store the next screen in the field memory 25 is shortened, and the screens are changed more closely, making the screen easier to see even during trick plays.

In this embodiment, the detection circuit that detects the zero position of the motor drive predicts the next peak position from the midpoint between the two reversal times of the polarity pressure of the phase comparator 30. This is to cancel out the error caused by the DC component of the phase error, and when the DC component of the phase error is small, the peak position can be found by simply counting the output of the waveform shaping circuit from the time when the polarity output of the phase comparator 30 reverses. It's okay.

Note that in FIG. 1, the detection circuit 41. Third Nuinch 431 frequency divider circuit 42. The control circuit 37 can also be realized by a microcomputer.

Effects of the Invention As described above, according to the present invention, the phase comparator generates an output corresponding to the phase difference between the phase of the synchronization signal and the phase of the reference synchronization signal, and the polarity of the voltage output from the drive circuit is reversed. The position is detected by the detection circuit, and the frequency dividing circuit generates a signal at that position to make the pickup jump, so it is possible to predict the time when the motor drive voltage will be zero and perform the jump operation at that time. be able to. Therefore,
When the pickup is jumping, the drive torque of the motor is zero, so when the motor is used to rotate the recording disk by inertia during the jump, it is possible to reduce the error in rotation control and shorten the time taken to control the motor after the jump. This makes it easier to see the screen during trick plays by switching between screens closely.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a recording disk reproducing apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram of a polarity reversal position detection circuit of a motor drive voltage of the recording disk reproducing apparatus according to an embodiment of the present invention.
FIG. 3 is a waveform diagram illustrating the operation of the recording disc reproducing apparatus according to the embodiment of the present invention, and FIG. 5 is a plan view showing the movement of the pickup during trick play of the recording disk reproducing apparatus according to the embodiment of the present invention, and FIG. 6 is a plan view showing the movement of the pickup during playback and trick play of the recording disk reproducing apparatus according to the embodiment of the present invention. FIG. 7 is a block diagram showing the configuration of a conventional recording disk reproducing device, and FIG. 8 shows the operation of the control circuit during trick play in a conventional recording disk reproducing device. FIG. 9 is a plan view showing the movement of the pickup during trick play in a conventional recording disc playback device; FIG. 10 is a flowchart;
The figure is a waveform diagram showing input signals to a motor drive circuit during playback and trick play in a conventional recording disc playback device. 21... Recording disc, 22... Group pickup, 3Q... Phase comparator, 33... Drive circuit, 34... Spindle motor, 36...・・・
...Jump circuit, 37...Control circuit, 41...
...detection circuit, 42... frequency division circuit. Name of agent: Patent attorney Shigetaka Awano and one other person

Claims (3)

[Claims] (1) A pickup that reads signals recorded on tracks of a recording disk and converts them into electrical signals, a motor that rotates the recording disk, and a motor that drives the pickup to track a track different from the track that the pickup is tracing. and a phase comparator that compares the phase of the synchronization signal recorded on the recording disk with the phase of a reference synchronization signal serving as a reference for rotation control of the motor and outputs a signal according to the phase difference. a drive circuit that receives the output of the phase comparator and generates a signal to rotate the motor; a detection circuit that detects a position where the polarity of the output voltage of the drive circuit is reversed; and a detection circuit that generates a signal at the position. 1. A recording disc reproducing apparatus, comprising: a frequency dividing circuit, wherein the control circuit determines a time at which to instruct the jump circuit to jump the pickup based on a signal generated by the frequency dividing circuit. (2) The phase comparator has a polarity output that is inverted depending on whether the phase of the synchronization signal is ahead or behind the phase of the reference synchronization signal, and the detection circuit is configured to invert the polarity output. 2. The recording disk reproducing apparatus according to claim 1, wherein the position at which the driving direction is reversed is detected by detecting that the spindle motor has rotated by a certain angle. (3) The phase comparator has a polarity output that is inverted depending on whether the phase of the synchronization signal is ahead or behind the phase of the reference synchronization signal, and the detection circuit is configured to output two polarity outputs. The recording disk reproducing apparatus according to claim 1, wherein the position at which the driving direction is reversed is detected by detecting that the spindle motor has rotated by a certain angle from the midpoint of the reversal position of the rotation. .