JPS62294385A - Camera integrated type vtr - Google Patents

Abstract

PURPOSE:To attain the recording of a video signal without jitter even when uneven rotation in a drum is generated, by providing the oscillator of a signal which becomes the base of the reference signal of a camera, and a control signal for a drum motor, and controlling the oscillation phase of the oscillator based on the rotation detecting signal of the drum on which a video head is mounted. CONSTITUTION:The oscillation phase of an oscillator 1 is controlled based on a shared oscillator 1 which generates an oscillation signal which becomes the base of the reference signal of a camera 9, and the control signal for a drum motor 11, a rotation detector 12 which detects the rotation of the drum on which the video head is mounted, and the rotation detecting signal from the rotation detector 12. In this way, it is possible to record the video signal without the jitter on a tape, even when uneven rotation is generated in the drum.

Description

[Detailed description of the invention] Detailed description of the invention [Industrial application field] The present invention relates to a camera-integrated VTR.

[Summary of the invention]

The present invention relates to a camera-integrated VTR, which includes a common oscillator that generates an oscillation signal that is the basis of a reference signal for the camera and a control signal for a drum motor, and the oscillator is activated based on a rotation detection signal of a drum to which a video head is attached. By controlling the oscillation phase, a jitter-free video signal can be recorded on the tape even if the rotation of the drum is uneven.

[Conventional technology]

Below, with reference to Fig. 2, a conventional camera-integrated VTR will be explained.
I will explain about it. (21) is a crystal oscillator, which generates an oscillation signal having a frequency of 8 fsc, which is eight times the color subcarrier frequency fsc, for example. This oscillation signal is supplied to a timing signal generation circuit (22) and frequency-divided by, for example, 1/2, thereby generating a timing signal with a frequency of 4 fsc.

This timing signal is supplied to the synchronization signal generation circuit (23), from which a reference signal (synchronization reference signal) with a frequency of 4 fsc and a control signal (control reference signal) with a frequency of fsc are obtained, respectively, and the respective cameras (24) ) and the drum servo circuit (25). Drum servo circuit (25)
The servo output from is supplied to the drum motor (26). (27) is a rotation detector that detects the rotation of the drum to which the video magnetic head is attached, here the rotation of the drum motor (26), and a rotation detection signal from this (for example, 1
The rotational frequency signal (with a frequency around kHz) is supplied to the drum servo circuit (25), and the synchronous signal generation circuit (25) is supplied to the drum servo circuit (25).
It is compared with a signal frequency-divided around 1 kHz of the control signal from 3), and the comparison output is supplied to the drum motor (26) to control its rotation.

[Problem that the invention seeks to solve]

In such conventional camera-integrated VTRs, the rotation of the drum is uneven, causing jitter in the time direction of the video signal recorded on the tape. Shaking or distortion may occur in the image.
If the video signal is a color video signal, problems such as color shift occurring in the reproduced image occur. In order to reduce this problem as much as possible, attempts have been made to increase the gain of the drum servo circuit, but there are limits to this due to the accuracy of the mechanical system and other factors.

In view of this, the present invention proposes a camera-integrated VTR that can record a jitter-free video signal on tape even if the rotation of the drum is uneven.

[Means for solving problems]

The camera-integrated VTR according to the present invention includes a common oscillator (1) that generates an oscillation signal that is the basis of a reference signal for a camera (9) and a control signal for a drum motor (11), and a common oscillator (1) that generates an oscillation signal that is the basis of a reference signal for a camera (9) and a control signal for a drum motor (11). The rotation detector (12) detects rotation, and the oscillation phase of the oscillator (1) is controlled based on the rotation detection signal from the rotation detector (12).

[Effect]

According to the present invention, the oscillation phase of the oscillator (1) is controlled based on the rotation detection signal from the rotation detector (12), so that even if the rotation of the drum is uneven, the tape can be easily adjusted. jitter-free video signals can be recorded.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to FIG. (1) is a PLL, which is a voltage-controlled variable oscillator (
2), consists of a frequency divider (3) that divides the oscillation output into 1/N, and a phase comparator (4) that compares the phase of the divided output of this frequency divider (3) and an external signal. ing. The oscillation center frequency of this oscillator (2) is, for example, 8 fsc.

The oscillation signal from this PLL (1), that is, its oscillator (2), is supplied to a timing signal generation circuit (7),
For example, if the frequency is divided by 1/2, the frequency will be 4fsc.
A timing signal is generated. This timing signal is supplied to the synchronization signal generation circuit (8), from which a reference signal (synchronization reference signal) with a frequency of 4 fsc and a control signal (control reference signal) with a frequency of fsc are obtained, respectively, and the camera (9 ) and the drum servo circuit (10).

Servo output from the drum servo circuit (10) is supplied to the tram motor (11). (12) is a rotation detector that detects the rotation of the drum to which the video magnetic head is attached, in this case the rotation of the drum motor (11). frequency signal) is supplied to the drum servo circuit (10), and 1k of the control signal from the synchronization signal generation circuit (8) is supplied to the drum servo circuit (10).
It is compared with a signal frequency-divided to a frequency around Hz, and the comparison output is supplied to the drum motor (11) to control its rotation.

Furthermore, the rotation detection signal from the rotation detector (12) is filtered through a bandpass filter (the passband center frequency of which is a value close to an integral multiple of 30Hz, which is the rotational frequency of the drum, for example 8
20Hz) (5) - supplied to the phase comparison circuit (4) of P LI, (1) through the DC blocking capacitor (6),
The phase is compared with the divided output from the frequency divider (3), and the comparison output is supplied to the oscillator (2) to control its oscillation frequency.

〔Effect of the invention〕

According to the present invention described above, even if the rotation of the drum is uneven, the oscillation phase of the oscillator is controlled accordingly.
A camera-integrated VTR capable of recording jitter-free video signals on tape can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional example. (1) is an oscillator (PLL), (9) is a camera, (11)
is a drum motor.

Claims (1)

[Scope of Claims] A common oscillator that generates an oscillation signal that is the basis of a camera reference signal and a control signal for a drum motor; a rotation detector that detects rotation of a drum to which a video head is attached; and the rotation detection. A camera-integrated VTR characterized in that the oscillation phase of the oscillator is controlled based on a rotation detection signal from the oscillator.