JPH07122035A - Rotary head type recorder - Google Patents

Abstract

PURPOSE:To obtain the rotary head type recorder, in which the problem such that the monitoring picture becomes asynchronous due to the deviation of rotating period of a rotary drum, is not generated even though the phase pull-in control is operated at the time of recording mode, while making the control enable to finish the phase lock of a drum motor against an inputted composite synchronizing signal in a short time. CONSTITUTION:When the recorder is on the recording mode, the alignment of rotary heads 2, 3 against the inputted synchronizing signal is performed by lst servo control means 11, 15. At the time of mode other than recording, the alignment of the rotary heads 2, 3 against the inputted synchronizing signal is performed by 2nd servo control means 18, 19 which make the aligning control of the rotary heads 2,3 finish in the time shorter than the case of the 1st servo control means 11,15. These procedures are selectively executed in such a manner that selecting means 20, 21 are controlled by a selection control means 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head type recording device such as a video tape recorder.

[0002]

2. Description of the Related Art Conventionally, in a rotary head type recording apparatus such as a video tape recorder, a head switch pulse indicating a rotation phase of a rotary head and a vertical synchronizing signal of a video signal to be recorded have a predetermined phase difference. Phase control of the rotating drum is performed. That is, in the NTSC type 8 mm video tape recorder, as shown in FIG. 2, the switching point of the head switch pulse in (a) is controlled to be about 6.0 H before the vertical synchronizing signal in (b).

FIG. 3 is a block diagram showing the structure of a conventional rotary head type recording apparatus. In FIG. 3, 1 is a drum motor for rotationally driving a rotary drum (not shown), and 2 is a first motor provided on the rotary drum. 1 rotary head, 3 is a rotary head that is offset from the first rotary head 2 by 180 degrees in the circumferential direction and is provided on the rotary drum, and 2 is a PG magnet (not shown) attached to the drum motor 1. PG signal detection head for detecting the PG signal of the head switch pulse signal generator 5 for generating a head switch pulse signal based on the detection signal output from the PG signal detection head 4.
A changeover switch 6 controls the recording video signal output from the video signal generator 7 by being controlled by the head switch pulse signal output from the head switch pulse signal generator 5 to the first rotary head 2 or the second rotary head. 3 is output alternatively.

Reference numeral 8 is an input terminal for inputting a composite sync signal of a recording video signal, 9 is a vertical sync signal separator for separating a vertical sync signal from the composite sync signal input from the input terminal 8, and 10 is a phase error signal generator. The detector detects the phase difference between the head switch pulse signal output from the head switch pulse signal generator 5 and the vertical synchronizing signal output from the vertical synchronizing signal separator 9 to generate a phase error signal. . Reference numeral 11 is a phase error signal amplifier (first servo control means) for adjusting the gain of the phase error signal output from the phase error signal generator 10, and 12 is an FG signal from an FG magnet (not shown) attached to the drum motor 1. FG signal detection head for detecting 1
Reference numeral 3 is an FG signal amplifier that amplifies the FG signal output from the FG signal detection head 12, and 14 is a speed error signal generator, which measures the cycle of the FG signal output from the FG signal amplifier 13 and sets a preset target. The speed error signal is generated in comparison with the cycle.

Reference numeral 15 is a speed error signal amplifier (first servo control means) for adjusting the gain of the speed error signal output from the speed error signal generator 14, and 16 is a phase system error output from the phase error signal amplifier 11. An adder circuit for adding the signal and the speed error signal output from the speed error signal amplifier 15; a motor driver 17 for driving and controlling the drum motor 1 based on the add signal output from the adder circuit 16; is there.

The operation of the drum motor 1 having the above-described structure to lock the phase with the composite synchronizing signal input from the input terminal 8 will be described.

The phase error signal generator 10 detects the phase difference between the head switch pulse signal output from the head switch pulse signal generator 5 and the vertical sync signal output from the vertical sync signal separator 9, and performs vertical sync. When the phase of the head switch pulse signal is ahead of the value shown in FIG. 2 with respect to the signal, a signal for delaying the rotation phase of the drum motor 1 and a phase of the head switch pulse signal for the vertical synchronizing signal are shown. When it is delayed from the value shown in 2, a signal for advancing the rotation phase of the drum motor 1 is output to the phase error signal amplifier 11.

The speed error signal generator 14 outputs a signal for increasing the rotation speed of the drum motor 1 when the cycle of the FG signal output from the FG signal amplifier 13 is slower than the target cycle, and also outputs from the FG signal amplifier 13. When the cycle of the generated FG signal is faster than the target cycle, a signal for decreasing the rotation speed of the drum motor 1 is output to the speed error signal amplifier 15.

The phase error signal amplifier 11 and the speed error signal amplifier 15 adjust the gains of the phase error signal and the speed error signal output from the phase error signal generator 10 and the speed error signal generator 14, respectively. Drum motor 1 for the input composite sync signal
Is set so as to stabilize and quickly lock the phase.

The phase error signal and the speed error signal output from the phase error signal amplifier 11 and the speed error signal amplifier 15 are added by the adder 16, and then the motor driver 17 rotates the drum motor 1. It is converted into a drive signal, and the drum motor 1 is rotationally driven by the drive signal.

[0011]

In the above-mentioned conventional apparatus, it is desirable that the phase lock of the drum motor 1 with respect to the composite synchronizing signal input from the input terminal 8 is stably and quickly ended, but the phase pull-in process is started. During the period from the end of the phase lock to the end of the phase lock, a deviation occurs in the rotation cycle of the drum motor 1 with respect to the vertical sync signal cycle of the composite sync signal, and the phase lock ends in a shorter period. As the phase error signal amplifier 11 and the speed error signal amplifier 15 are set, the amount of this deviation increases.

However, in the recording mode, when the continuity of the composite sync signal input from the input terminal 8 is temporarily interrupted and the phase pull-in process is performed again,
A problem arises when the amount of deviation is large. That is, when the portion in which the phase pull-in process is performed in the recording mode is reproduced, the rotation cycle of the drum motor 1 largely changes between the recording mode and the reproduction mode. Disturbance may occur and synchronization may not be established on the monitor screen.

Therefore, it is necessary to set the phase error signal amplifier 11 and the speed error signal amplifier 15 in consideration of the deviation, and there is a limit in setting the phase pull-in processing period short.

The present invention has been made in view of the above circumstances, and controls the phase pull-in in the recording mode while enabling the control in which the phase lock of the drum motor with respect to the input composite synchronizing signal is completed in a short time. Another object of the present invention is to provide a rotary head type recording apparatus in which the problem that the monitor screen cannot be synchronized due to the deviation of the rotation cycle of the rotary drum does not occur.

[0015]

In order to achieve the above object, the present invention provides a rotary head type recording apparatus for aligning a rotary head with respect to an input synchronizing signal, wherein the rotary head responds to the synchronizing signal. Positioning control of the rotary head with respect to the synchronization signal and first servo control means for performing position alignment control, and position control of the rotary head with respect to the synchronization signal in a shorter time than the first servo control means. The second servo control means to be terminated, the selection means for selecting the first and second servo control means, and the selection control means for controlling the selection means according to the operation mode of the rotary head type recording apparatus are provided. It is characterized by that.

[0016]

When the rotary head type recording apparatus is in the recording mode, the first position adjustment of the rotary head with respect to the input synchronizing signal is performed.
Servo control means, and when not in the recording mode,
The selection control is performed by the selection device such that the rotary head is aligned with the input synchronization signal by the second servo control device that completes the alignment control of the rotary head in a shorter time than the first servo control device. Controlled by means.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a block diagram showing the configuration of a rotary head type recording apparatus according to an embodiment of the present invention. In FIG. 1, the same parts as those of the conventional FIG. 3 described above are designated by the same reference numerals. explain. 1 is different from FIG. 3 in that FIG.
The second phase error signal amplifier (second servo control means) 18, the second speed error signal amplifier (second servo control means) 19, a pair of selection switches (selection means)
20, 21 and a control switch (selection control means) 22 are added.

The second phase error signal amplifier 18 and the second
The speed error signal amplifier 19 of FIG. 2 can lock the phase of the drum motor 1 with respect to the composite synchronizing signal input from the input terminal 8 in a shorter time than the first phase error signal amplifier 11 and the first speed error signal amplifier 15. Is set as follows.

The selection switches 20 and 21 are controlled by the signal level set by the control switch 22, and when the control switch 22 is in the open state (OFF),
When the output signals of the first phase error signal amplifier 11 and the first speed error signal amplifier 15 are selected, the output signals are output to the adder 16, and when the control switch 22 is in the closed state (ON). Is the second phase error signal amplifier 18
And an output signal of the second speed error signal amplifier 19 is selected and the output signal is output to the adder 16. The control switch 22 is set to the open state (OFF) when the apparatus is in the recording mode, and is set to the closed state (ON) at other times.

In the case where this apparatus is a camera-integrated VTR (video tape recorder), the continuity of the composite sync signal inputted from the input terminal 8 is always maintained in the mode for recording the photographed image of the camera. The setting state of the control switch 22 may be set to the closed state (ON) in the mode for recording the image captured by the camera and to the open state (OFF) in the mode for recording the signal input from the external input terminal. There is no.

The rest of the configuration and operation of this embodiment are the same as those of the above-mentioned conventional example, and therefore their explanations are omitted.

[0023]

As described above in detail, according to the rotary head type recording apparatus of the present invention, by setting a plurality of servo loops and selecting and controlling the servo loops according to the operation mode of the apparatus, Even if the phase pull-in control is performed in the recording mode, it is possible to synchronize the monitor screen from the deviation of the rotation cycle of the rotating drum while enabling the control to finish the phase lock of the drum motor to the input composite sync signal in a short time. The problem of disappearing does not occur.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a rotary head type recording apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a phase relationship between an input composite synchronizing signal and a head switch pulse signal.

FIG. 3 is a block diagram showing a configuration of a conventional rotary head type recording apparatus.

[Explanation of symbols]

2 1st rotary head 3 2nd rotary head 11 1st phase error signal amplifier (1st servo control means) 15 1st speed error signal amplifier (1st servo control means) 18 2nd phase error Signal amplifier (second servo control means) 19 Second speed error signal amplifier (second servo control means) 20 Selection switch (selection means) 21 Selection switch (selection means) 22 Control switch (selection control means)

Claims (1)

[Claims] 1. A rotary head type recording device for aligning a rotary head with respect to an input synchronizing signal, comprising: first servo control means for performing alignment control of the rotary head with respect to the synchronizing signal; Second servo control means for performing alignment control of the rotary head with respect to a signal and ending alignment control of the rotary head with respect to the synchronization signal in a shorter time than the first servo control means; 2. A rotary head type recording apparatus comprising: a selection means for selecting the second servo control means; and a selection control means for controlling the selection means according to an operation mode of the rotary head type recording apparatus.