JPH0636261B2 - Magnetic recording / reproducing device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus having a loading mechanism for winding a magnetic tape around a cylinder and recording or reproducing an image signal on the magnetic tape. It is a thing.

2. Description of the Related Art Magnetic recording / reproducing apparatus for recording / reproducing video signals (hereinafter referred to as V
In TR, a magnetic tape (hereinafter referred to as a tape) is loaded into a tape cassette (hereinafter referred to as a tape) by a loading mechanism.
It is pulled out from the cassette), wound around a cylinder, and recorded by a magnetic head attached to the cylinder.
Play back.

A method using a loading motor has been mainly used as a method for driving a loading mechanism for winding a tape around a cylinder. However, it is difficult to reduce the size of the device because a dedicated loading motor is required.
It was one of the reasons for the cost increase.

Therefore, a method of removing the loading motor by driving the loading mechanism using a capstan motor that drives the tape and winding the tape around a cylinder has been developed. (The Journal of Japanese Society of Mechanical Engineering, Vol. 90, No. 824
In this system, the capstan motor is rotated at a constant speed to drive the loading mechanism, move the loading post, and wind the tape around the cylinder.

The movement of the loading post is managed by a microcomputer (hereinafter abbreviated as a mechanical control) that controls the mechanism of the VTR, and the mechanical damage is prevented by stopping the post at a predetermined position. . Further, the mechanical controller measures whether or not the loading operation is normally performed by measuring the moving time of the loading post.

Therefore, in order to stop the loading post at a predetermined position, when the loading mechanism is driven by the capstan motor, the loading post must be moved at a constant speed. Therefore, the capstan motor is rotated at a constant speed to keep the moving speed of the loading post constant regardless of the tape reproducing time mode and the VTR recording time mode. For example, the loading post is moved at a constant speed via the transmission mechanism by setting the servo system to the recording mode and rotating the capstan motor at a speed five times faster than the standard time mode.

In order to move the loading post at a constant speed,
The servo system for both the cylinder motor and capstan motor is in the recording mode. Therefore, the phase reference signal of the cylinder motor is in the recording mode at the time of loading regardless of the recording / reproducing mode.

FIG. 3 shows a block diagram of the cylinder phase control system. 1 is a mode input terminal for inputting a recording / playback mode,
The recording mode is input at the time of loading. 3 is a video signal input terminal to which a video signal is input, and 4 is a vertical sync signal separated from the video signal input from the input terminal 3 to 1/2
Vertical synchronizing signal separating means for frequency division 5, 5 is a phase reference signal generating means for generating a reference signal of the cylinder phase control system in the reproduction mode, and 6 is an output signal of the vertical synchronizing signal separating means 4 and a reference phase signal generating means 5. Reference signal switching means for switching the output signal according to the input signal of the mode input terminal 1, 7 for cylinder phase control means for controlling the phase of the cylinder motor based on the output signal for the reference signal switching means, 8 for capstan control means, The input signal of the mode input terminal 1 is input.

The reference signal switching means 6 switches so as to input the output signal of the vertical synchronizing signal separating means 4 in the recording mode and the output signal of the phase reference signal generating means 5 in the reproducing mode to the cylinder phase control means 7.

Therefore, regardless of the VTR recording / playback mode,
At the time of loading, the mode signal input to the mode input terminal 1 becomes the recording mode, so that the reference signal switching means 6 causes the reference signal of the cylinder phase control system to become the output signal of the vertical synchronizing signal separating means 4.

However, in the above configuration, the recording mode is set at the time of tape loading regardless of the recording / playback mode, and the reference signal of the cylinder phase control system becomes the vertical synchronizing signal. Since the reference signal of the cylinder phase control system is the vertical synchronization signal, the phase pull-in characteristic does not deteriorate, but in the reproduction mode, the internal reference mode, that is, the phase reference signal becomes the output signal of the phase reference signal generating means after loading, so the phase pull-in characteristic There was a problem that was worse.

According to the present invention, even when the servo system of the VTR is set to the recording mode at the time of tape loading and the loading mechanism is moved at a constant speed by the capstan motor, the phase pull-in of the cylinder phase control system is quickly performed in each of the recording and reproducing modes. It is an object.

Means for Solving the Problems In order to achieve the above object, in a magnetic recording / reproducing apparatus of the present invention, a cylinder motor that rotationally drives a cylinder having a rotary head, and a phase control unit that controls a rotational phase of the cylinder motor. A capstan motor for driving the magnetic tape, a loading means for driving the magnetic tape through a transmission means to wind the magnetic tape around the cylinder, a mode discrimination means for discriminating a recording / reproducing mode, and a video image. Vertical synchronizing signal separating means for separating the vertical synchronizing signal from the signal, phase reference signal generating means for generating the phase reference signal, and phase reference signal for the cylinder motor when the magnetic tape is wound around the cylinder by the loading means. When the determination result of the mode determining means is the recording mode, the vertical sync signal separation is performed. Means for selecting the output signal of the means and for selecting the output signal of the phase reference signal generating means in the reproduction mode.

The present invention has the above-mentioned configuration, when the loading mechanism is driven by the capstan motor, it is determined whether the recording mode or the reproduction mode, and the vertical synchronization signal is selected as the reference signal of the cylinder phase control system in the recording mode.
By selecting the output signal of the phase reference signal generating means in the reproducing mode, the phase pull-in of the cylinder motor after the loading can be promptly performed.

Embodiment An embodiment of the magnetic recording / reproducing apparatus of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a cylinder phase control system showing an embodiment of the present invention. The same parts as those in FIG. 3 are designated by the same reference numerals, and a duplicate description will be omitted. The following points are different between FIG. 1 and FIG. A recording or reproducing mode is input to the mode input terminal 1 regardless of the loading mode. Reference numeral 2 is a mode discriminating means for discriminating the recording / reproducing mode of the servo system by inputting the signal from the mode input terminal 1, and a loading mode signal is inputted from the input terminal 9. The output signal 2a of the mode discriminating means 2 is input to the switching signal of the reference signal switching means 6, and the output signal 2b is input to the capstan control means 8.

First, when the VTR is in the stop mode, the tape is stored in the cassette and not wound around the cylinder. At this time, both the cylinder motor and the capstan motor are stopped.

Next, when the VTR enters the recording mode, the mode input terminal 1
The recording mode is input to the mode determining means 2 from. Further, since the tape is not loaded in the cylinder, a loading signal is also input from the loading mode input terminal 9 to the mode discriminating means 2. The mode discrimination means 2 outputs the recording mode to each of the reference signal switching means 6 and the capstan control means 8. The capstan control means 8 rotates the capstan motor at a constant speed so that the moving speed of the loading post becomes constant. Then, the loading mechanism pulls out the tape from the cassette and winds the tape around the cylinder.

Even if the tape loading is completed, the output signal of the mode discriminating means 2 does not change from the recording mode because the VTR is in the recording mode. Therefore, even after the end of loading, the phase reference signal input to the cylinder phase control means 7 is the output signal of the vertical synchronizing signal separation means 4, and the phase pull-in is performed quickly. Further, the capstan control system 8 is V
The tape is driven in the recording time mode in which TR is set.

On the other hand, when the VTR is in the reproduction mode, the reproduction mode is input from the mode input terminal 1 to the mode discriminating means 2. Further, since the tape is not loaded in the cylinder, a loading signal is also input from the loading mode input terminal 9 to the mode discriminating means 2. The mode discriminating means 2 outputs a recording mode for loading a tape on the capstan control system 8. Then, when the loading is completed, the reproduction mode is output. The mode discriminating means 2 outputs the reproduction mode to the reference signal switching means 6 and switches the phase reference signal of the cylinder motor to the output signal of the phase reference signal generating means 5 which is the reference phase signal of the reproduction mode. Therefore, the phase reference signal input to the cylinder phase control means 7 becomes the output signal of the phase reference signal generation means 5.

As described above, the reference signal of the cylinder phase control means 7 becomes the vertical synchronizing signal at the time of recording and the output signal of the phase reference signal generating means 5 at the time of reproduction, so that the phase pull-in can be performed quickly.

FIG. 2 is a signal waveform diagram showing the operation of the cylinder phase control system, and a is an output signal waveform of the vertical synchronizing signal separating means 4, which is a reference signal in the recording mode. b is a trapezoidal wave signal created by the cylinder phase control means 7 based on the reference signal of a. c is a cylinder head switch (hereinafter, HSW
Is a signal waveform, and is a waveform diagram of the result of the phase control performed by the phase control means 7 so that the trailing edge of the HSW signal comes to the center of the trapezoidal wave signal of b.

That is, a, b, and c represent operating states of the cylinder phase control system in the recording mode.

Next, d is the output signal waveform of the phase reference signal generating means 5, which becomes the phase reference signal of the cylinder in the reproduction mode. e
Is a trapezoidal wave signal created by the cylinder phase control means 7 based on the reference signal of d. f is the HSW signal waveform of the cylinder, and is a waveform diagram of the result of the phase control performed by the phase control means 7 so that the trailing edge of the HSW signal is located at the center of the trapezoidal waveform of e.

That is, d, e, and f represent operating states of the cylinder phase control system in the reproduction mode.

Here, the phase reference signal a in the recording mode and the phase reference signal d in the reproduction mode do not always have the same phase, and this embodiment shows the case where the phases are shifted by the time T. Since the phase of the reference signal is deviated, when the cylinder phase control system changes from the recording mode to the reproduction mode, the cylinder phase reference signal also changes from the recording mode vertical synchronizing signal a to the output signal of the reproduction mode phase reference signal generating means 5. Since it becomes d, the phase of the reference signal is shifted by the time T. As a result, it takes time for the phase control system to pull in.

However, since the phase reference signal of the cylinder motor is made to be the phase reference signal according to the recording or reproduction mode at that time by the mode discriminating means 2, the reference signal of the cylinder phase control system is being loaded. The same holds true after loading, and the phase pull-in of the cylinder motor can be performed quickly.

In the operation mode of the capstan motor, the loading post must be moved at a constant speed, so that the loading mode is fixed at the time of loading as before.

EFFECTS OF THE INVENTION As described above, the present invention provides a cylinder motor that rotationally drives a cylinder having a rotary head, a phase control unit that controls the rotational phase of the cylinder motor, a capstan motor that drives a magnetic tape to travel, A loading means driven by a capstan motor through a transmission means to wind the magnetic tape around the cylinder, a mode determination means for determining a recording / reproducing mode, and a vertical synchronization signal separation for separating a vertical synchronization signal from a video signal. Means, a phase reference signal generating means for generating a phase reference signal, and the phase reference signal of the cylinder motor when the magnetic tape is wound around the cylinder by the loading means when the determination result of the mode determining means is the recording mode. Select the output signal of the vertical sync signal separation means, and select the phase in the playback mode. A phase reference signal switching means for selecting the output signal of the reference signal generating means,
Even if the capstan control system is set to the recording mode at the time of loading, the reference signal of the cylinder phase control system is switched to the reference signal according to the recording / reproducing mode by the mode discriminating means and the phase reference signal switching means. It can be done quickly.

[Brief description of drawings]

FIG. 1 is a block diagram of a cylinder phase control system in an embodiment of the present invention, FIG. 2 is a signal waveform diagram for explaining the operation of FIG. 1, and FIG. 3 is a block diagram of a conventional cylinder phase control system. Is. 2 ... Mode discrimination means, 4 ... Vertical sync signal separation means,
5 ... Reference phase signal generating means, 6 ... Reference signal switching means.

Claims (1)

[Claims] 1. A cylinder motor for rotationally driving a cylinder having a rotary head, a phase control means for controlling a rotational phase of the cylinder motor, a capstan motor for driving and driving a magnetic tape, and a transmission means from the capstan motor. Driving means for winding the magnetic tape around the cylinder, a mode discriminating means for discriminating a recording / reproducing mode, a vertical synchronizing signal separating means for separating a vertical synchronizing signal from a video signal, and a phase reference signal. And a vertical reference signal separating means when the discriminating result of the mode discriminating means is the recording mode when the magnetic tape is wound around the cylinder by the loading means. Of the phase reference signal generating means in the reproduction mode. Magnetic recording and reproducing apparatus characterized by comprising a phase reference signal switching means for selecting the power signal.