JPH08129804A - Intermittent magnetic recorder - Google Patents

Abstract

PURPOSE: To stably record a control signal even at the time of intermittent recording by recording a magnetic tape with a reference pulse of a control signal generated by a recording CTL generating circuit in counting an output pulse of a frequency generator equipped on a capstan motor. CONSTITUTION: The intermittent magnetic recorder is used for such a camera for picking up a slow motion object in compressed time. A pulse of a frequency proportionate to a rotating speed of a capstan motor (i), outputted by a frequency generating circuit (j) equipped on the motor (i) in the recorder is counted by an FG counter, and based on a counting result, the reference pulse of the control signal is generated by the recording CTL generating circuit (f). Then, the reference pulse is recorded on the magnetic tape (t) by a control head I. By this constitution, even at the time of intermittent recording of unstable traveling, the control signal can stably be recorded on the magnetic tape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermittent magnetic recording device for intermittent recording, which is used in a camera or the like for time-compressing and photographing a slow-moving target object.

[0002]

2. Description of the Related Art Conventionally, the followings have been proposed for such an intermittent magnetic recording device. The capstan motor is intermittently driven to intermittently run the tape, and a video signal for one field is recorded during the running period, and at the same time, a control signal is recorded during the running period. In this case, when recording the control signal, a voltage is applied to the control head after a predetermined time delay from the switching signal of the video head to switch N / S of the magnetic field.

[0003]

However, in the above method, the control signal period is not constant except for a special system in which the intermittent feeding of the tape is always constant. In this case, tape running becomes unstable. That is, when recording a signal during tape running in which the tape movement state is unlikely to be constant at all, such as intermittent feeding, it is difficult to accurately record the control signal at a constant cycle by the method described above. .

The present invention clarifies a magnetic recording apparatus capable of recording a constant and stable control signal even in the intermittent recording in which the tape running is unstable as described above.

[0005]

In an intermittent magnetic recording apparatus in which a magnetic tape (t) is intermittently run and recording is performed during the running, the frequency provided by a capstan motor (i) for driving the magnetic tape. A reference signal is recorded on the magnetic tape based on the signal of the generator (j).

[0006]

[Operation and Effect] Since the reference signal is recorded on the magnetic tape based on the signal from the frequency generator (j) of the capstan motor (i) for driving the magnetic tape, the intermittent feeding operation is somewhat unstable. Also, the recording control pulse can be recorded on the magnetic tape by accurately measuring the tape movement amount. Therefore, since it is not necessary to increase the feeding accuracy of the mechanism itself, it is possible to realize even a normal consumer VTR without increasing the cost.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The magnetic recording apparatus of the present invention is basically different from the conventional example in that a capstan motor is intermittently driven to intermittently run a tape and a video signal for one field is recorded during the running period. Since they are the same and the configurations are almost the same,
A detailed description of the configuration will be omitted, and the functional aspects will be mainly described below.

FIG. 1 shows a block diagram of an embodiment of the present invention. (i) is a capstan motor for moving the magnetic tape (t), and two known frequency generators (j) (k) for generating pulses having a frequency proportional to the rotation thereof.
(Hereinafter referred to as FG), and one FG (k) is attached so that the phase is delayed by 90 degrees with respect to the other FG (j).

Reference numeral (n) is a rotary magnetic head for recording a signal on the magnetic tape (t) or reading a signal on the magnetic tape (t).

(O) is a motor for rotationally driving the rotary magnetic head (n).

(I) is for applying N to the magnetic tape by applying a voltage.
The control head records a control signal as a magnetic field or an S magnetic field.

(A) is a start pulse generation circuit, which generates a capstan start pulse of a predetermined width in synchronization with the head switching pulse in the intermittent recording mode.

Reference numeral (b) is a braking pulse generating circuit for stopping the magnetic tape (t) at a time point when the capstan motor (i) is activated and a predetermined distance is moved in the intermittent recording mode. , Counts the FG pulses output from the FG (j) included in the capstan motor (i), and generates a capstan braking pulse.

(C) shows the capstan motor (i) at a predetermined speed based on the head switching pulse and the FG pulse,
It is a rotation control circuit for rotating in phase.

(D) is a drive motor for the rotary magnetic head (n)
This is a circuit for controlling the rotation of (o).

(G) is a recording state of the rotary magnetic head (n),
Alternatively, it is a circuit for controlling the reading state.

(H) is an OR gate for transmitting the outputs of the starting pulse generating circuit (a), the braking pulse generating circuit (b) and the rotation control circuit (c) to the capstan motor (i) during intermittent driving. ..

(S) shows the output of the OR gate (h) of the start pulse, the braking pulse and the rotation control signal during intermittent recording, and the rotation control signal during continuous recording.
It is a switch for transmitting to (i).

(E) is an FG counter newly added in the present invention, which is provided after the start pulse is output during intermittent recording.
Count the pulses of FG (j) attached to the capstan motor (i). This count value is sent to a recording control signal (hereinafter referred to as CTL) creating circuit (f) described later.

The FG counter (e) also receives the FG (k) pulse at the same time, detects the rotational direction of the capstan motor (i) at the same time based on the phase difference between the two pulses, and adds / counts the count. Subtracting. That is, in the forward rotation, the count is added, and in the reverse rotation, the count is subtracted.

In (f), when the value of the FG counter (e) in the recording CTL creating circuit reaches a predetermined value N1, a pulse of N pole (high pulse) is added to the control head (I),
When the value of the FG counter (e) reaches a predetermined value N2, a control signal is recorded on the magnetic tape (t) by applying a south pole pulse (low pulse) to the control head (I).

FIG. 2 is a timing chart of the actual operation. (A) is a head switching pulse, and channels 1 and 2 of the rotary magnetic head are switched based on this signal.

(B) is the starting pulse initial generation circuit (a) of FIG.
The starting pulse (c) created in (3) is a braking pulse created in the braking generation pulse circuit (b) of FIG.

(D) is an output pulse of the FG (j) attached to the capstan motor (i), and this pulse is counted by the FG counter (e) which is a feature of the present invention. still,
The number under (d) is this count value.

(E) is a recording mode signal which actually puts the magnetic head in a recording state.

(F) is a voltage applied to the control head (I) at the output of the recording CTL creating circuit (f) of FIG.

However, when the intermittent recording mode is entered and the recording operation is started, the start pulse generation circuit (a) creates a start pulse (b) with the head switching signal (a) as a reference,
Start the capstan motor (i).

When the capstan motor (i) starts rotating, a pulse (d) is output from the FG (j) attached to the motor. This pulse is counted by the FG counter (e), and when it reaches a predetermined value (6 in this example), the recording CTL
The production circuit (f) outputs (f) a high voltage. This is a magnetic tape (t) as an N-pole magnetic field by the control head (I).
Recorded above.

Further, at the same time, F
The G pulses (d) are counted, and when a predetermined value (11 in the example) is reached, a braking pulse (c) is applied to the capstan motor (i) to stop the capstan motor (i).

Also in the next intermittent feed, the start pulse (b) is created with the start switching pulse (a) as a reference in the start pulse generating circuit (a) as before, and the capstan motor (i)
To start.

When the capstan motor (i) starts rotating, a pulse (d) is output from the FG (j) provided in the motor. This is counted by the FG counter (e), and when the count value reaches a predetermined value (21 in the example), the recording CTL creation circuit (f) outputs a low voltage (f), and the control head (I ) To record an S-pole magnetic field on the magnetic tape (t).

At the same time, the braking pulse generation circuit (b) counts the FG pulses (d), and when the value reaches a predetermined value (24 in the example), the braking pulse (c) is applied to the capstan motor (i). Is added to stop the capstan motor (i).

The value of the FG counter (e) is the recording CTL.
It clears when the start pulse (b) occurs when the output of the creation circuit (f) is low. In addition, the FG counter (e) accurately detects the tape moving direction by FG (j) and FG (k) which is delayed by 90 degrees in phase to measure the accurate tape moving amount, and the count is added based on the detected direction. / Try to perform subtraction.

Recording of video signals by the magnetic head (n)
When the recording mode signal (e) in FIG. 2 becomes high, the recording / reproducing control circuit (g) is brought into a recording state and the signal is recorded on the magnetic tape (t).

By the above method, even if there is a slight change in the intermittent feeding of the magnetic tape, the control pulse can be accurately recorded on the magnetic tape, so that the recorded portion is reproduced (normal reproduction, not intermittent reproduction). Even when this is done, smooth playback is possible without causing tape running fluctuations due to servo control.

Needless to say, the above system can be realized by using a general-purpose logic integrated circuit, a dedicated integrated circuit, or a microcomputer. Further, the present invention is not limited to the configuration of the above embodiment, and various modifications can be made within the scope of the claims.

[Brief description of drawings]

FIG. 1 is a block diagram of a device of the present invention.

FIG. 2 is a timing chart in the device of the present invention.

[Explanation of symbols]

 (a) Start pulse generation circuit (b) Braking pulse generation circuit (c) Capstan motor rotation control circuit (d) Magnetic head drive motor rotation control circuit (e) FG counter (f) Recording CTL creation circuit (g) Recording , Regeneration control circuit (i) capstan motor (j) frequency generator

Claims (2)

[Claims] 1. A magnetic tape (t) is run intermittently,
An FG counter (e) for counting pulses from a frequency generator (j) provided in a magnetic tape running drive capstan motor (i) in an intermittent magnetic recording device for recording while running, and an FG Control head (I) according to the value of counter (e)
An intermittent magnetic recording apparatus comprising a recording CTL creating circuit (f) for applying a voltage to the magnetic tape (t) to record a control signal. 2. A capstan motor (i) having a frequency generator (j) for generating a signal of a frequency proportional to the rotational speed of the magnetic tape (t) for controlling the running of the magnetic tape (t), and a predetermined signal input. A capstan motor drive pulse generation circuit (c) that drives a magnetic tape (t) by generating a motor drive pulse and applying a drive pulse of a predetermined width to the capstan motor (i), and a predetermined signal input By applying a braking pulse of a predetermined width to the capstan motor (i) to stop the capstan motor (b), a signal is magnetically recorded on the magnetic tape (t) or recorded on the magnetic tape (t). Head (n) for reading the signal being recorded
A rotation control circuit (d) for controlling the rotation of the magnetic head (n), a recording / reproduction control circuit (g) for controlling the magnetic head (n) in a recording state or a reproducing state by a predetermined signal, and the cap. The FG counter (e) that counts the pulses from the frequency generator provided in the stun motor (i), and the control head (I) according to the value of the FG counter (e)
An intermittent magnetic recording device comprising a recording CTL creating circuit (f) for applying a voltage to the magnetic tape (t) to record a control signal.