JPS60242537A - Magnetic tape recording device - Google Patents

Abstract

PURPOSE:To prevent fine powder from sticking on a head in a recording stand- by state by moving a tape by a specific quantity at specific intervals of time shorter than the time when fine powder of the tape sticks on the head. CONSTITUTION:The Q output terminal of a monostable multivibrator 18 is connected to the reset terminal R of a counter 17 through an OR gate 15, so a specific-time (15min) recording stand-by state and a specific time (15sec) recording state are obtained alternately. Therefore, when heads 1 and 2 trace the magnetic tape 3, the tape is run for 5sec at intervals of 15min and they shift in tracking position, so that the heads 1 and 2 never scan the same position on the tape 3 for >=15min. In general, when the heads 1 and 2 trace the same position on the tape 3 repeatedly for 20-30min, fine powder due to the peeling of the magnetic surface sticks on the heads 1 and 2, but no powder sticks in a shorter period of 15min.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a diagonal scanning magnetic tape recording apparatus such as a VTR that starts recording after a relatively long recording standby time.

2. Description of the Related Art A diagonal scanning type VTR capable of obtaining a recording standby state (record standby state or pause state) is already known. In the recording standby state, the magnetic tape is generally kept in a stopped state, but the magnetic head is kept in a rotating state and in contact with the magnetic tape.

Problems to be Solved by the Invention By the way, if the recording standby state is set for a relatively long period of time, the same part of the tape will be traced over and over again, and the magnetic surface of the tape will gradually peel off, resulting in minute traces. Head clog occurs when the powder sticks to the tip of the magnetic head, increasing the distance between the head and the tape, making normal recording or reproduction impossible. In order to solve this problem, there is a method of weakening the tension of the magnetic tape in the recording standby state (1), but as long as the head is in contact with the tape, fine particles will inevitably stick to the head.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a magnetic tape recording device that can prevent fine powder from adhering to a head using a simple method.

Means for Solving the Problems In order to achieve the above object, the present invention is configured to be able to obtain a recording standby state in which the magnetic head is rotated and the magnetic tape is brought into contact with the magnetic head in a stopped state. In the diagonal scanning rotary head type magnetic tape recording device, the recording standby state is shorter than the time length during which fine powder generated from the magnetic tape adheres to the magnetic head due to the recording standby state (for a set predetermined time period). The present invention relates to a magnetic tape recording device characterized in that a control circuit is provided which automatically repeats the process of moving the magnetic tape by a predetermined amount when the magnetic tape continues, and then returning to the recording standby state.

According to the above invention, if the time from when the recording standby state is set to when the recording mode is set is long, the recording standby state is not set continuously and the /FT fixed time (for example)
When 55 minutes have elapsed, the tape is automatically moved by a predetermined amount, and the recording standby state is resumed. Therefore, dressing of the same portion of the magnetic tape is prevented, and fine powder of the magnetic tape is prevented from adhering to the head.

Embodiment Next, a video tape recorder (VTR) according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. A rotary head type VT configured in the diagonal scanning method similar to
R, a pair of rotating magnetic heads tll (21, a guide drum (4J) for diagonally running the tape (31), a capstan (5), a pinch roller (6), a tape running mechanism (7)
J, Recording standby operation switch (8j, Recording operation switch (
9], two D-type flip-flops (IQ
A control port ii! containing a known part such as Iu and further according to the invention! Including betting.

The data input terminal (1) of the recording standby flip-flop t101 is always connected to the positive power supply +V, and the clock input terminal (C) is connected to the power supply +VK via the standby operation switch (8) with a normally open configuration. . Therefore, when the switch (8) is turned on, the Q output of the flip-flop a becomes high level. The data input terminal (tD) of the seven recording lip-flops aυ is always connected to the positive power supply +V, and the clock input terminal (CJ) is connected to the power supply +vlC via the recording operation switch +91 which is normally open. Flip frog (111
Q output becomes high level.

In addition, the reset terminal (R) of the flip-frog αQ is connected to the output side of the recording operation switch (9).

Since the reset terminal (R) of the flip-flop (E) is connected to the output *t+ of the standby operation switch (8), 2
The Q outputs of the two flip 70 tubes Go7Qυ are prevented from going high at the same time.

Control circuit M (121 is AND) Q3, first and second OR gates α41 (1ω and 1 oscillator (161, 7)
It consists of a 7 counter←η and a monostable multivibrator (2), and selectively sets the recording standby state or the recording state in response to the outputs of two flip-flops aψUυ.

Next, the operation of the apparatus shown in FIG. 1 will be explained with reference to FIGS. 2 and 3. Now, when the standby operation switch (8) is turned on at time 11 in Fig. 2, the 7 rib frog (I
The pulse shown in Fig. 2 (2) is input to the clock input terminal (c) of Q+, and the Q output of flip 70 toggle QQI is
Convert to high level as shown in Figure B.

At the same time, the pulse shown in Fig. 2 (2) is input to the reset terminal (R) of another -1 7-lip-flop a, and if the flip-flop (111) is set, it is reset.The Q output terminal of the flip-flop (101) is an AND gate (-1 input terminal of 13 +K connected, AND gate) Q
The other input terminal of 3i is connected to the Q output terminal of the monostable multi-by-break bet.
As shown in the t2 period, the monostable multivibrator α rare Q
When the output terminal is at a high level, the output of the AND gate α4 becomes a high level as shown in the period 11 to t1 in FIG. , the tape (3) is wound diagonally around the drum (44) and rotates once (the head ridge (21) rotates.
At this time, the tape (3) is kept in a stopped state. - 1,000, 1 in Figure 2. At this point, when the Q output terminal of the flip-flop (101f) changes from high level to low level as shown in Figure 2 (0), the Q output terminal of the flip-flop (101f) becomes O.
It is connected to the reset terminal (RJ) of the counter (I7) via the R gate (15).

The reset state of the counter aD is released and the counter starts counting the output pulses of the oscillation chamber of, for example, 18 Hz. Then, when counting the 117th) predetermined time T1 set to about 15 minutes, the
Generates a 5 minute count output pulse.

The output terminal of the counter (17) is connected to the trigger input terminal of the monostable multivibrator α mallet in response to the counting output pulse at time 12 in Fig. 2 (1). The second predetermined time T is set to approximately 5 seconds from the Q output terminal as shown in FIG.

The high level output pulse of t! -13 period, and the low level output shown in FIG. 2 [F] is obtained from the Q output terminal. As a result, in the period t, ~t, ANDgu)Q
The output of 31 becomes a low level as shown in FIG. 7) because it is connected to.

During the period t2 to t3, a high level signal shown in FIG. 2 is supplied as a recording control signal, and the tape (3) runs.

Since the Q output terminal of the monostable multivibrator α is connected to the reset terminal of the counter via the OR gate, the counter aη is kept in the reset state during the 11 period, and at the 13 time point the Q When the output becomes low and changes to a bell, counting starts.Then, the first predetermined time 'L (
15 minutes) is counted, and at the 14th point, Figure 2 (Dvc
A pulse shown is generated, and the same operation as in the period t2 to t8 occurs at t.
Occurs in the period 4-t2. As a result, 1 recording operation switch (
9) is in a recording standby state for a first predetermined time TI (approximately 15 minutes) until it is turned on.

A recording state for a second predetermined time Tz (approximately 5 seconds) is obtained alternately. Therefore, the head 1 on the magnetic tape 131
The trace position according to 1+[21 also changes every 15 minutes, as shown by the line in Figure 3. The trace position changes by the amount of travel.Therefore, the magnetic tape (3)
The head (January 2J) will not scan the same PJ'r for more than 15 minutes.
1ffJ -m head is) (20 to 3 depending on 2j)
Repeated tracing for about 0 minutes causes the fine powder to stick to the head peak (2) due to peeling of the magnetic surface, but in this example, it is shorter than 20 to 30 minutes. Since the head peak i2J moves to the tape position of , no head clock is generated due to peeling of the magnetic surface.

When the recording operation switch (9) is turned on at time 16 (as shown in FIG. 2 (I+)), the Q output terminal of the recording flip-flop aυ becomes high level (as shown in FIG. 2 (Jl)).
Then, as shown in FIG. 2 (Bl (C1) (standby 7 lip-flop 00) is reset.
The Q output of is connected to the tape running mechanism (7) via the first OR gate I (), so when the Qlfj force of slip flock a becomes high level at time 16, this acts as a recording control signal. Then, the VTR enters the recording state.1
If you perform a recording operation at time 6, the previous state is the standby state, the drum (41K tape (3) has already been wound, and the head tll (2J) is already rotating, so it quickly becomes ready for recording. , after the 16th point in time, the Q output of the standby flipflora 1αQ is as shown in Fig. 2 (0
As shown in the figure, the level becomes high.

The counter ση is kept in a reset state, and the Q output of the monostable multivibrator α8j is kept in a low level state.

Until the recording operation switch (9) is operated at time point 16, the tape +31 runs for 5 seconds every 15 minutes, but the tape running time - is extremely short (5 seconds), so the tape ( The amount of unnecessary use of 31 is extremely small.

Modifications The present invention is not limited to the above-mentioned embodiments, but the following modifications are possible, for example.

(at The counter aη may not be reset based on the output of the monostable multivibrator α, but may be reset based on the output of the L force as shown by the chain line in FIG. 1. The counter aη is in the reset state only during the high-level pulse period of FIG. The time obtained by subtracting the output pulse period T2 of the stable multi-buy break bet becomes the Jth predetermined time (standby state time).

(b) The slip-flock aOJaυ may be an RSS free-lag flop. Further, the control circuit u4 and/or the flip-flop (101 (1υ) may be configured with a microprocessor or the like.

(c) It is not limited to a 2-head type (it may also be applicable to a 4-head type).

(dl In the embodiment, the recording state is set during the period 1.~”am t4~t5, etc., and the tape (3) is run.
It is also possible to only run the tape at the same or different speed than the normal running speed. That is, the recording signal thread may be kept in a standby state and only tape running may be performed.

(It is also applicable when remotely controlling the switch (8J(9)).

(Instead of the fl counter aη, a timer such as a monostable multivibrator may be used.) It is also applicable when recording audio signals.

Effects of the Invention As is clear from the above, according to the present invention, since the tape is moved at regular time intervals of 75r, it is possible to prevent the fine magnetic powder from adhering to the head during the recording standby state.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a VTR according to an embodiment of the present invention, FIG. 2 is a waveform diagram showing voltage states of A to JA in FIG. 1, and FIG. 3 is a contact of the head to the magnetic tape in FIG. 1. This is a plan view showing the location. (1 bar 2j...magnetic head, (31...magnetic tape, (8)...recording standby operation switch, (9j...recording operation switch, (101(1υ...2 rig float, tt Enoki ... Control circuit, α (capital) ... AND game 1 (141 ... OR gate, (17) ... Counter, a phrase ... Monostable multivibrator. Agent Norihiro Takano Figure 1 Figure 2 Procedural Amendment (Voluntary) October 25, 1980 Manabu Shiga, Commissioner of the Japan Patent Office Display of 12F 1982 Patent WR Koji No. 97307 2, Title of invention Magnetic tape recording device 3, Person making amendment case Relationship with Applicant 5゜ Date of amendment order Proprietor 6 Number of inventions increased by amendment 7, Claims of the specification to be amended and detailed description of the invention [11 Claims as shown in the attached document Correct. Delete "the recording standby 086000. was set" from line 6 of f21 8A affidavit 4 to line 9 of the same page. 2. Claims (11) Rotating the magnetic head and recording the magnetic tape In a diagonal scanning rotary head type magnetic tape recording device configured to be able to obtain a recording standby state in which the magnetic head is brought into contact with the magnetic head in a stopped state, if the recording standby state is continued for a predetermined time, the A magnetic tape recording device characterized by being provided with a control circuit that automatically repeats the process of moving the magnetic tape by a predetermined amount and then returning to the recording standby state. (2) A predetermined amount of the magnetic tape 2. The magnetic tape recording apparatus according to claim 1, wherein the movement is performed by setting the magnetic tape in a recording state for a predetermined period of time and causing the magnetic tape to run.

Claims (1)

[Scope of Claims] A diagonal scanning rotary head type magnet configured to be able to obtain a recording standby state in which the magnetic head is rotated and the magnetic tape is brought into contact with the magnetic head in a stopped state. If the tape recording device is allowed to continue in the recording standby state for a predetermined period of time that is shorter than the length of time during which fine particles generated from the magnetic tape adhere to the magnetic head due to the recording standby state, the magnetic A magnetic tape recording device comprising a control circuit that automatically repeats the process of moving the tape by a predetermined amount and then returning to the recording standby state. (2) Moving the magnetic tape by a predetermined amount. 2. The magnetic tape recording apparatus according to claim 1, wherein: the magnetic tape is set to a recording state for a predetermined period of time and runs the magnetic tape.