JPS6258460A - Motor controller - Google Patents

Abstract

PURPOSE:To stably synchronize a video signal and the rotation phase of a motor with each other by using a rotation phase reference signal which does not use the output of a field discriminating means when synchronization between rotation of the motor and the external video signal is detected. CONSTITUTION:When synchronization between rotation of a motor 13 and the external video signal is detected by a rotation synchronization detecting circuit 17, a field is discriminated in accordance with the rotation phase reference signal and the rotation phase reference signal of a square wave having two-fold period of a vertical synchronizing signal is outputted because the output of a field discriminating circuit 5 and that of a vertical synchronizing signal separating circuit 4 are inputted to a rotation phase reference signal generating circuit 6. A phase comparator 7 compares the phase of the pulse signal outputted from a rotation pulse detecting circuit 12 with the phase of the square wave signal outputted from the rotation phase reference signal generating circuit 6 and detects lead/lag of the rotation phase of the motor 13. The detected phase error signal is converted to a voltage value and is outputted to an adder 8 to control the motor 13.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention records information on a disc-shaped recording medium (hereinafter referred to as a disc) used in a video disc, etc. The present invention relates to a motor control device used in a recording/reproducing device that reads information.

BACKGROUND ART FIG. 6 shows a block diagram of a conventional example of a motor control device used in a system for recording information on a disk.

In FIG. 6, 1 is an external video signal generator such as a VTR. 2 is a composite synchronization signal detection circuit. This is composed of a comparator and the like, and extracts a composite synchronization signal component from the video signal output from the external video signal generator 1. 3 is a horizontal synchronization signal separation circuit. This is composed of a monomulti, etc., and separates the horizontal synchronization signal component from the output of the composite synchronization signal detection circuit 2. 4 is a vertical synchronization signal separation circuit. This consists of a low-pass filter and the like, and separates the vertical synchronization signal component from the second output. Reference numeral 5 denotes a field identification circuit, which is composed of gate circuits and the like, and identifies even fields in the video signal from the output of the composite sync signal detection circuit 2, the output of the horizontal sync signal separation circuit 3, and the output of the vertical sync signal separation circuit 4. Then, a pulse-like signal is output to the rotational phase reference signal generation circuit 6.

The rotational phase reference signal generation circuit 6 uses the vertical synchronization signal output from the vertical synchronization signal separation circuit 4 and the pulse-like signal output from the field identification circuit 6 that determines whether the field is even or odd to determine the vertical synchronization signal bar. has a frequency,
Generates a square wave rotating phase reference signal with fixed field phase.

12 is a rotational pulse detection circuit, which is composed of a light emitting diode and a light receiving element, and a disk 1 attached to the motor.
1 and outputs a pulse-like signal. 7 is a phase comparator, which detects the phase difference between the rectangular wave signal output from the rotation phase reference signal generation circuit 6 and the pulse signal output from the rotation pulse detection circuit 12, and converts the phase difference into a voltage value. Convert and output.

14 is a frequency generator attached to the motor 13. The frequency generators 1 and 4 output signals with a frequency proportional to the rotation speed of the motor 13.

16 is an F-V conversion circuit, which converts the frequency signal output from the frequency generator 14 into a voltage signal.

A speed comparator 16 compares the voltage signal output from the y-v conversion circuit 16 with an internal reference voltage to detect a rotational speed error of the motor 13. Reference numeral 8 denotes an adder composed of an operational amplifier or the like, and the output of the phase comparator 7 and the output of the speed comparator 16 are added by the adder 8. The output signal of this adder 8 is output to an amplifier circuit 9, and the output of the amplifier circuit 9 is output to a motor drive circuit 10 to drive the motor 1.
3 is controlled.

The problem that the invention seeks to solve FIG. 7 shows a composite synchronization signal of the NTSC system.

The narrow pulse in FIG. 7 (6) is the horizontal synchronizing signal, and the wide pulse in FIG. 7 (0) is the vertical synchronizing signal.

FIG. 7 shows only the waveforms before and after the vertical synchronization signal. This is because the above method is an odd number method in which the number of scanning lines is odd and interlaced scanning is performed.

As shown in FIG. 7, there are two cases in which the relationship between the horizontal synchronizing signal and the vertical synchronizing signal is shifted by A cycle of the horizontal synchronizing signal. The case in FIG. 7(G) is called an odd field, and the case in FIG. 7(J) is called an even field.

The equalization pulse shown in FIG. 7(i) stabilizes vertical scanning by making the waveforms of the vertical synchronizing signal the same before and after the two fields.

As mentioned above, in a regular composite sync signal, the above two fields are arranged alternately as an odd field, an even field, and an odd field, but in the case of a video signal edited via a VTR etc., the tape editing In some cases, a synchronization signal is formed in which odd-numbered fields or even-numbered fields are adjacent to each other.

In a motor control circuit that extracts a composite synchronization signal from an externally input video signal and always performs field determination of the composite synchronization signal, as in the conventional example described above, the video signal in which the fields are arranged in an irregular manner as described above is generated. When input, there is a problem in that the phase of the rectangular wave signal, which is the reference for the rotational phase of the motor shown in the conventional example, is disturbed in the irregular portion, and the rotation of the motor is disturbed.

Further, as shown in FIGS. 7(G) and (J), the difference between odd and even fields is that the relationship between the vertical synchronizing signal and the horizontal synchronizing signal is shifted by the period of the horizontal synchronizing signal. Therefore, in the field detection circuit shown in the above conventional example, W periods of the horizontal synchronization signal (about 30 μ5e
c) It is necessary to detect a very short time difference, and it is susceptible to noise or dropouts on the external video signal. Therefore, in the case of the above-mentioned conventional example, there is a problem in that the synchronization of the motor is disturbed due to noise or dropout on the external video signal.

The present invention has been made in view of this point, and even when a video signal having irregularly arranged fields as described above or a video signal with many noises and dropouts is input, the video signal and the motor can be The object of the present invention is to construct a motor control device that can stably synchronize the rotational phases of the motors.

Means for Solving the Problems In order to solve the above problems, the present invention includes a rotation synchronization detection circuit for detecting synchronization between an external video signal and the rotation of the motor, and a field identification circuit for identifying fields of the external video signal. A switch consisting of a gate circuit, etc. is installed between the circuit and the rotational phase reference signal generation circuit that generates the reference signal for the rotational phase of the motor, and the synchronization of the motor rotation and the external video signal is detected by the rotational synchronization detection circuit. If this happens, the switch is opened to prevent the output signal of the field identification circuit from being input to the rotational phase reference signal generation circuit, and in other cases, the switch is made conductive to prevent the output signal from the field identification circuit from being input to the rotational phase reference signal generation circuit. The configuration is such that a signal is input to a rotational phase reference signal generation circuit.

Further, the switch has a configuration that can also be opened by an output signal from a keyboard or the like provided outside the motor control device of the present invention.

Effects The present invention has the above-described configuration, so that the rotation of the motor can be stably synchronized even for video signals with irregular fields or video signals with a lot of noise and dropouts. It is possible to easily configure a system for recording and reproducing bad video signals.

Embodiment FIG. 1 is a block diagram showing an embodiment of a motor control device of the present invention. In FIG. 1, 1 is an external video signal generator, 2 is a composite sync signal detection circuit, 3 is a horizontal sync signal separation circuit, 4 is a vertical sync signal separation circuit, and 6 is a field identification circuit. Identical components in FIG. 1 and FIG. 4 are given the same numbers.

18 in FIG. 1 is a switch. It is composed of gate circuits, analog switches, relays, etc., and is turned on/off by the output signals of 17 rotation synchronization detection circuits. 6 is a rotational phase reference signal generation circuit. This embodiment uses flip-flops. The switch 18 is in a conductive state (
On), a rectangular wave rotational phase reference signal having a negative frequency of the vertical synchronization signal is generated from the output signal of the vertical synchronization signal separation circuit 14 and the output signal of the field identification circuit 6.

When the switch 16 is open (off), only the output signal of the vertical synchronization signal separation circuit 4 is input, and a rectangular wave rotational phase reference signal having the frequency of the bar of the vertical synchronization signal without field discrimination is generated. .

Reference numeral 17 denotes a rotation synchronization detection circuit, which is composed of a seven-knob, a gate circuit, a counter, etc., and receives the pulsed signal output from the rotation pulse detection circuit 12 shown in FIG. 1 and the output of the rotation phase reference signal generation circuit 6. By comparing the phase relationship of the signals, it is detected that the motor 3 is rotating in synchronization with the external video signal.

Regarding the motor control device configured as above, the following is the first part.
The operation will be explained using figures.

The switch 18 remains on until the rotation synchronization detection circuit 17 detects synchronization between the rotation of the motor 13 and the external video signal. At this time, since the output of the field identification circuit 5 and the output of the vertical synchronization signal separation circuit 4 are both input to the rotational phase reference signal generation circuit 6, field discrimination is not performed from the rotational phase reference signal as described above. , and a rectangular rotational phase reference signal having a period twice that of the vertical synchronization signal is output. Since the rotational phase reference signal is field-identified, it will be at a low level when an even field of an external video signal is input, and will be at a high level when an odd field of an external video signal is input. The state of the rotational phase reference signal is determined by the field of the external video signal.

Next, in the phase comparator 7 of FIG.
The phase of the pulse signal outputted from the rotational phase reference signal generation circuit 2 and the rectangular wave signal outputted from the rotational phase reference signal generation circuit 6 are compared to detect the lead or lag in the rotational phase of the motor 13 (disc).

The detected phase error signal is converted into a voltage value and sent to an adder 8.
The motor 13 is controlled. As a result, when the rotation of the motor 13 and the external video signal are synchronized, the output of the rotation pulse detection circuit 12 and the rotation phase reference signal are the rectangular wave signal in FIG. , (n
) and (P).

The operation of the synchronization detection circuit 17 will be explained using FIG. FIG. 2(A) shows the output signal of the rotational phase reference signal generation circuit 6. T1 in FIG. 2(A) corresponds to the period of one rotation of the motor 13. (B) is a gate signal created by a monomulti, etc. in the rotation synchronization detection circuit 17. This is the number from the rising edge of the signal in FIG. 2(m). As mentioned in the explanation of the phase comparator 7 above, when the rotation of the motor 13 is phase-locked with the external video signal, the phase of the gate signal (in Figure 2) and the pulse signal in Figure 2 (C) is Match. In the rotation synchronization detection circuit 17 of this embodiment, as shown in FIG.
, (C) The number of times that the phases of the signals match is counted using a counter inside the rotation synchronization detection circuit 17. When the counted value exceeds a certain value, a high level signal is output as shown in Fig. 2). As in the case of the pulse signal (m) shown in FIG. 2(C), if the phases of the signals in FIG. 2(B) and (C) do not match even once, the 5 rotation period detection circuit 17 The internal counter is reset and its output becomes low level as shown in FIG. 2(D). The rotation synchronization detection circuit 17 of this embodiment detects the synchronization of the rotation of the motor 13 and the external video signal as described above.

When the output of the rotational synchronization detection circuit 17 is at a high level, the switch 18 remains off, and when the output of the rotational synchronization detection circuit 17 is at a low level, the switch 18 is turned on.

Next, a description will be given of how the rotational phase reference signal changes depending on whether the switch 18 is turned on or off.

As described above, in this embodiment, a flip-flop is used in the rotational phase reference signal generation circuit 6.

The operation of this flip-flop will be explained using FIGS. 3 and 4. FIG. 3 shows the case where the switch 1B is on, and FIG. 4 shows the case where the switch 18 is off.

In both FIGS. 3 and 4, (R) is the output signal of the vertical synchronization signal separation circuit 4 (S) is the output signal of the field identification circuit 6, and σ
) is the rotational phase reference signal.

As shown in FIGS. 3 and 4, the rotational phase reference signal σ) is triggered by the signal σ) and alternates between a high level state and a low level state. The signal (S) is a signal that resets the high level state of the rotational phase reference signal (T) to a low level state as shown in FIG. FIG. 3 shows a case where the signal σ) is reset by the pulse (5) in FIG. 3, and the phase is reversed before and after the pulse (A). In the case of FIG. 4, since the above-mentioned reset signal is not input, the phase of the signal σ) does not change even if the pulse (A) is generated.

As described above, when the switch 18 is in the on state, the rotational phase of the motor 13 is reset by the output of the field identification circuit S, and a synchronized state is established in which one rotation of the motor 13 corresponds to one frame of the external video signal. I can do it. After the synchronization state as described above is achieved, the switch 18 is turned off, and a rotational phase reference signal is generated using the output of the vertical synchronization signal separation circuit 4. This is because the vertical synchronization signal is resistant to noise.

The phase relationship between the motor 13 and the external video signal determined when the switch 18 is on is maintained as it is even after the switch 18 is turned off.

FIG. 6 shows another embodiment of the present invention, in which the switch 18 can be turned on/off directly using an externally provided keyboard 19 or the like.
Turn off. According to this embodiment, the motor 13 can be stably rotated even when the fields in the external video signal are frequently reversed or when the frames are completely indistinguishable.

This device can be used as a motor control device used in a system for recording information on a disk. If the rotation of the motor is disturbed when the system is in the recording state, the signal recorded on the disc will also be disturbed. Therefore, in this device,
A motor control device is configured that turns off the switch in response to a recording mode signal output from a command device in the system when the system becomes ready for recording, and controls the motor using a rotational phase reference signal that is not judged in the field during recording. be able to.

Effects of the Invention As described above, according to the present invention, the rotation of the motor can be stably synchronized even with a video signal in which the fields are arranged in an irregular manner or a video signal with poor S/H. Therefore, as described above, even a video signal having a partially normal field or a video signal with a poor S/N ratio can be stably recorded on a disk, which has a great effect.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a motor control device according to an embodiment of the present invention, FIG. 2 is a waveform diagram of a main part of its rotational synchronization detection circuit, and FIG. 3 is a waveform diagram of a main part of its rotational phase reference signal generation circuit. , FIG. 4 is a waveform diagram of the main part of the rotational phase reference signal generation circuit, FIG. 6 is a block diagram showing a motor control device in another embodiment of the present invention, and FIG. 6 is a block diagram of a conventional motor control device. 7 are waveform diagrams of the NTSC system composite synchronization signal. 17... Rotation synchronization detection circuit, 7... Phase comparator, 8... Adder, 9... Amplifier circuit, 10... Drive circuit, 6... Rotational phase reference signal generation circuit, 11... Disc, 1
3...Motor%18...Switch.

Claims (3)

[Claims] (1) A rotational speed detection means that outputs a signal with a frequency proportional to the rotational speed of the motor, a frequency-voltage conversion means that converts the output of the rotational speed detection means into a voltage value, and a ratio between the voltage value and a reference voltage value. speed comparison means for comparing and outputting a signal according to the error; and a synchronization mark provided on the motor or a disk attached to the motor to detect the rotation angle of the disk or the motor. rotational pulse detection means; synchronization signal separation means for extracting a synchronization signal from an externally inputted video signal; field identification means for identifying a field of the external video signal; and an output of the synchronization signal separation means and the field identification means. a reference signal generating means for generating a rotational phase reference signal of the motor using the output of the rotational phase reference signal; and a reference signal generating means for generating a rotational phase reference signal of the motor using the output of the rotational phase reference signal, and comparing the rotational phase reference signal and the output signal of the rotational phase detection means and outputting a signal corresponding to the phase difference. a phase comparison means; a signal amplification means for adding and amplifying the output of the phase comparison means and the output of the speed comparison means; a motor drive means for rotationally driving the motor by the output of the signal amplification means; and a switch connected between the field identification means and the reference signal generation means and opened and closed by the output of the rotation synchronization detection means, When the rotation synchronization detection circuit detects synchronization between the rotation of the motor and the external video signal, the switch is opened, and the reference signal generation means outputs a rotation phase reference signal that does not use the output of the field identification means. A motor control device characterized in that the signal is used as a rotational phase reference signal for the motor. (2) The motor control device according to claim 1, wherein the switch is opened and closed by a signal input from an external switch. (3) The motor control device according to claim 1, wherein the switch is opened when a recording mode signal is input from a command device in the recording/reproducing device.