JPH0660495A - Control method for motor for driving information recording and reproducing mechanism - Google Patents

Abstract

PURPOSE:To always complete pull-in of a phase within a shortest time when a reference phase signal is changed to a vertical synchronizing signal by making a first vertical synchronizing signal which appears immediately after the reference phase signal is changed to the vertical synchronizing signal as the reference signal and making the vertical synchronizing signal as the staring point of frequency dividing in two. CONSTITUTION:When a reference phase switching signal 9 switches selection of a reproducing reference phase signal 11 to selection of a vertical synchronizing signal 12, an internal frequency dividing counter of a frequency divider in two 13 is reset. Also, the signal 12 is selected to an input of a phase error detector 7 as a reference phase signal 10, and compared with a phase detector 6 in phase every input of the signal 10, and a phase error is given to a frequency divider in two reset signal generator 16. The generator 16 outputs a reset signal 17 to the frequency divider in two 13 when a signal 9 is a first value of the signal 12 every input of phase errors, and makes the next signal 12 as the starting point of frequency dividing in two. Thereby, phase pull-in time can be surely shortened without causing omission of phase error detecting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a motor for driving an information recording / reproducing mechanism for controlling the phase of a drum motor or a capstan motor of a video tape recorder.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing a conventional controller for a motor for driving an information recording / reproducing mechanism.
1 is a drum motor (motor), 2 is a frequency generator (FG) for detecting the speed of the drum motor 1, and 3 is an error between a speed signal from the frequency generator 2 and a predetermined speed of the drum motor 1. The speed error detectors 4 and 4 are D / A converters that convert the speed error signal output from the speed error detector 3 into an analog signal.

Reference numeral 6 is a rotation phase detector (PG) for detecting the rotation phase of the drum motor 1, and reference numeral 7 is an error between the phase signal from the rotation phase detector 6 and a reference phase signal according to the reproduction mode or the recording mode. A phase error detector, 14 is a D / A converter for converting the phase error signal output from the phase error detector 7 into an analog signal, and 5 is a mixture of the speed error signal and the phase error signal converted into the analog signal. Mixer,
A drive circuit 15 drives the drum motor 1 by the mixed speed error signal and phase error signal to control the rotation speed and the rotation phase.

Next, the operation will be described. In FIG. 3, a frequency generator 2 having 24 teeth is attached to the drum motor 1, and the frequency generator 2 is rotated during normal rotation.
Thus, a velocity signal of about 720 Hz is obtained, and this velocity signal is input to the velocity error detector 3. The speed error detector 3 measures the cycle of this speed signal, and the speed error corresponding to the number of rotations of the drum motor 1 is converted into a digital signal by the D / A converter 4.
To the mixer 5, and the D / A converter 4 converts the analog signal into an analog signal and supplies it to the mixer 5. Further, the drum motor 1 is provided with a rotation phase detector 6 for detecting the rotation phase, and this phase signal is input to the phase error detector 7. The switch circuit 8 selects the reference phase signal 10 input to the phase error detector 7 based on the reference phase switching signal 9. When the reference phase switching signal 9 is in the reproduction mode, the reproduction reference phase signal 11 of 30 Hz is selected, and in the recording mode, the vertical synchronizing signal 12 of 60 Hz extracted from the video signal is inputted to the frequency divider 13 and is divided by the frequency divider 13. The signal divided by 30 Hz is selected. The phase error detector 7 compares the phases of the reference phase signal 10 and the phase signal from the rotary phase detector 6, outputs the phase error as a digital signal to the D / A converter 14, and the D / A converter 14 Is converted into an analog signal and given to the mixer 5. The mixer 5 mixes the speed and phase error signals, drives the drum motor 1 via the drive circuit 15, and controls the rotation speed and the rotation phase thereof.

[0005]

Since the conventional method for controlling the motor for driving the information recording / reproducing mechanism is constructed as described above, the vertical synchronizing signal 12 is always divided by 2 to obtain the reference phase signal 10. , When the reproduction mode is changed to the recording mode, that is, when the reference phase signal 10 is changed from the reproduction reference signal 11 to the vertical synchronizing signal divided by two,
Depending on the timing of the mode change, the phase error may not be detected for the first vertical synchronization signal after the mode change.

This will be described in more detail with reference to the timing chart of FIG.
When the recording mode is changed to the recording mode at the point A, the output PG1 of the rotary phase detector 6 obtains a phase error with respect to the output S1 of the reproduction reference phase signal 11, and PG2 greatly differs from the divided-by-2 vertical synchronizing signal V22. Therefore, when the recording mode is changed at the time point A, the first vertical synchronization signal V after the change is generated.
4, the phase error can be obtained. On the other hand, when the phase reference switching signal 9 changes to the recording mode at the time point B, there is no effective divide-by-2 vertical synchronizing signal in PG1, so that the phase error with V22 is first obtained in PG2. Therefore, when the recording mode is changed at the time point B, the phase error cannot be obtained for the first vertical synchronization signal V3 after the change.

Further, as described above, when the recording mode is changed at the time point A, the phase error with the divide-by-2 vertical synchronizing signal V22 can be obtained. V22 is a signal synchronized with V5 which is the closest to PG2. However, there is a problem that it takes time to pull in the phase.

The present invention has been made to solve the above problems, and when the reference phase signal changes to the vertical synchronizing signal, the information recording / reproducing mechanism can always complete the phase pull-in in the shortest time. An object of the present invention is to provide a method for controlling a drive motor.

[0009]

According to a first aspect of the present invention, there is provided a method for controlling an information recording / reproducing mechanism driving motor, wherein the first vertical synchronizing signal after the reference phase signal is changed to the vertical synchronizing signal is used as the reference phase signal. In addition, the vertical synchronizing signal is used as the starting point of the frequency division by two.

According to a second aspect of the present invention, there is provided a method of controlling a motor for driving an information recording / reproducing mechanism, which detects a phase error based on the first vertical synchronizing signal after the reference phase signal is changed to the vertical synchronizing signal. The process of determining the magnitude of the absolute value of the detected phase error, which is one half of the vertical synchronization signal cycle, and when the determination result is small, the vertical synchronization signal is set to the vertical synchronization signal as the starting point of the frequency division by two. It is provided with a process of dividing the frequency by 2 and a process of dividing the vertical synchronizing signal by 2 with the next vertical synchronizing signal as a starting point of the dividing by 2 when the above judgment result is large.

[0011]

When the reference phase signal changes to the vertical synchronizing signal, the phase error is always detected from the first vertical synchronizing signal after the change when the reference phase signal changes to the vertical synchronizing signal. Always minimize the time to start the phase pull-in operation.

According to a second aspect of the present invention, there is provided a method of controlling a motor for driving an information recording / reproducing mechanism, which detects a phase error based on a first vertical synchronizing signal when a reference phase signal changes to a vertical synchronizing signal, and detects the phase error. Based on the magnitude relationship between the absolute value of the phase error and one half of the vertical synchronizing signal period, the closest vertical synchronizing signal to the rotary phase detector is determined, and the phase pull-in operation is performed on the vertical synchronizing signal, and By setting the starting point of the frequency division by 2, the phase error is accurately detected, and the phase pull-in operation time is completed in the shortest time.

[0013]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a control device for a motor for driving an information recording / reproducing mechanism according to an embodiment of the present invention.
In FIG. 1, the same parts as those in the conventional example shown in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted. A feature of this embodiment is that the frequency divider reset signal generator 16 is provided, and the output of the phase error detector 7 of the conventional example and the reference phase switching signal 9 are supplied to the frequency divider reset signal generator 16. And the point where the reference phase switching signal 9 is given to the frequency divider 13. The 2 frequency divider reset signal generator 16 gives a reset signal 17 to the 2 frequency divider 13 and the 2 frequency divider 13 resets the inner partial frequency counter by the reset signal 17 and sets the next vertical synchronizing signal 12 as a reference phase. Signal 10
As the starting point for dividing by two.

Next, the operation will be described. FIG. 2 is a flow chart showing a method of controlling an information recording / reproducing mechanism driving motor according to an embodiment of the present invention, which will be described with reference to FIG. 1 and FIG. First, the reference phase switching signal 9
Is changed from the selection of the reproduction reference phase signal 11 to the selection of the vertical synchronizing signal 12, the inner partial frequency counter of the frequency divider 13 is reset. Further, the vertical synchronization signal 12 is selected as the reference phase signal 10 as the input of the phase error detector 7,
Each time the reference phase signal 10 is input, the phase with the rotational phase detector 6 is compared, and the phase error is given to the divide-by-2 frequency divider reset signal generator 16 as a digital signal. Here, the divide-by-2 divider reset signal generator 16 receives a phase error every time
It is determined whether the reference phase switching signal 9 is the reproduction reference phase signal 11 or the vertical synchronization signal 12 (step S1).
00). As a result, when the vertical synchronization signal 12 is selected, it is determined whether the detected phase error is the first value after the reference phase signal 10 is changed to the vertical synchronization signal 12 (step S101). When the result is the changed first phase error, the absolute value of the phase error is ½ of the cycle of the vertical synchronization signal 12 (about 8.33 mse in the broadcasting form NTSC).
c) It is determined whether or not (step S102), and if it is 1/2 or more, the next vertical synchronizing signal 12 is set as the starting point of the frequency division by 2, so the reset signal 17 is output to the frequency divider 13 (step S103). . Next, in order to pull the phase of the rotary phase detector 6 into the vertical synchronizing signal 12, the detected phase error is corrected by the following equation, and the corrected detected phase error is output to the D / A converter 14 (step S104). a) When the detected phase error is +8.33 msec or more Detected phase error = Detected phase error -16.67 msec b) When the detected phase error is -8.33 msec or more Detected phase error = Detected phase error +1.67 msec

Although the method of controlling the drum motor has been described in the above embodiment, the same effect can be obtained by using this control method for the capstan motor.

[0016]

As described above, according to the invention of claim 1, the first vertical synchronizing signal after the reference phase signal is changed to the vertical synchronizing signal is used as the reference phase signal, and the vertical synchronizing signal is 2 Since it is configured to be the starting point of the frequency division, the phase error detection can always be performed from the first vertical synchronization signal after the change without leakage of the phase error detection, and the phase pull-in time can be surely shortened. There is an effect that can be.

According to the second aspect of the invention, the phase error is detected based on the first vertical synchronizing signal after the reference phase signal is changed to the vertical synchronizing signal, and the absolute value of the detected phase error is detected. Processing for determining whether the vertical synchronization signal period is 1/2 or less, and if the determination result is small, processing for dividing the vertical synchronization signal by two using the vertical synchronization signal as a starting point for dividing by two; When the judgment result is large, the vertical synchronizing signal is divided into two by using the next vertical synchronizing signal as a starting point of dividing by two, and therefore, the accurate phase error can be detected and the reference phase error can be detected. There is an effect that the time from the change of the phase signal to the vertical synchronizing signal to the completion of the phase pull-in can be minimized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a control device for a motor for driving an information recording / reproducing mechanism according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a method of controlling an information recording / reproducing mechanism driving motor according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a conventional controller for a motor for driving an information recording / reproducing mechanism.

FIG. 4 is a timing chart showing the operation of FIG.

[Explanation of symbols]

 1 Drum motor (motor) 10 Reference phase signal 12 Vertical synchronization signal

Claims (2)

[Claims] 1. A motor for rotating a drum or a capstan, wherein when recording or reproducing, a signal obtained by dividing a vertical synchronizing signal of a recording or reproducing video signal by two is one of reference phase signals representing a rotation phase of the motor. In the information recording / reproducing mechanism driving motor control method for detecting the phase error of the motor and performing the phase error detection process, the first vertical synchronization signal after the reference phase signal is changed to the vertical synchronization signal is used as the reference phase signal, A method of controlling a motor for driving an information recording / reproducing mechanism, characterized in that the vertical synchronizing signal is used as a starting point for dividing the frequency by two. 2. A motor for rotating a drum or a capstan, wherein when recording or reproducing, a signal obtained by dividing a vertical synchronizing signal of a recording or reproducing video signal by two is one of reference phase signals representing a rotation phase of the motor. In the information recording / reproducing mechanism driving motor control method for detecting the phase error of the motor and performing the phase error detection processing, the phase error detection is performed based on the first vertical synchronization signal after the reference phase signal is changed to the vertical synchronization signal. Is performed and the magnitude of the detected absolute value of the phase error is determined to be 1/2 of the vertical synchronizing signal period. If the result of the determination is small, the vertical synchronizing signal is divided by two. It is characterized by comprising a process of dividing the vertical synchronizing signal by two as a starting point and a process of dividing the vertical synchronizing signal by two with the next vertical synchronizing signal as a starting point of dividing by two when the above judgment result is large. A method for controlling a motor for driving an information recording / reproducing mechanism.