JPS5911570A - Reversing system of two-capstan deck - Google Patents

Abstract

PURPOSE:To reverse the running direction of a tape in a short time, by controlling two DD motors and pinch rolls constituting two tape driving mechanisms in order with a time difference. CONSTITUTION:A reversing preparation signal S1 is outputted when the part just before the end of a magnetic tape T running at the FWD mode is detected at a tape position operating circuit 21, a pinch roll P2 is detached from the magnetic tape T and the DD motor M2 is driven reversely. The tape T is run at the FDW mode at this point of time with a single driving of a motor M1. When an end detecting signal S2 of the tape T is inputted next, the roll P1 is detached from the tape T, the tape T is brought momentarily to a free state, but since the roll P2 is pressed on the tape T, the tape T runs reversely by the driving force of the motor M2. The motor M1 is driven reversely after detaching of the pinch roll P1 and when the motor is controlled to bring the pinch roll P1 into press-contact with the tape T after reaching the normal number of revolutions, then the tape T is changed to the REV mode driven by the two capstans.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reverse system for a tape recorder that employs a double capstan system (hereinafter referred to as the 2-capstan system) deck driven by a DD motor (Direct Drive). It is something.

As shown in FIG. 1, a two-capstan type tape recorder drives if and a second capstan 1゜2 by first and second DD motors (not shown), and records data stored in a cassette C. The tape 3 is pinched between pinch rollers 4 and 5 and then run. In this figure, 6.
7 is a recording head and a reproducing head, 8 is an erasing head, and 9 is a pad. Further, 1θ, 11 is a feed wheel for the capstans 1, 2, and 12.13 is a pinch ruler 4, 5 which is suppressed by a mechanism not shown in the drawings when the tape 3 is played back (recorded). It is an operating plate.

In a two-capstan deck with such a structure, the drive hub part and the magnetic head part of the cassette C are connected to the capstan 1.2. In addition, by pinching the tape 3 with the pinch ruler 4.5, insulation is achieved, which is effective against torque unevenness on the winding side due to variations in the cassette C and play in the hub drive shaft. However, the wow of the DD motor
Flywheel with sufficiently large inertia to improve flutter and modulation noise caused by vibration10.11
It is required to provide

Therefore, since the flywheel 10.11 with large inertia is used as mentioned above, the tape 3 being played back on such a two-capstan deck should have an auto 11 forwarding function. Even after the direction of rotation is reversed at the end of the tape, it takes a long time to reach steady rotation, and as a result, relatively long sound breaks occur when playing (recording) with auto-reverse.

This invention was made in view of the refreshing autumn season.
The reversing operation of the DD motor is controlled with a time difference so that the tape reversing drive time is shortened.

Hereinafter, 1) the parsing method of the 2-capsun deck of the present invention will be explained.

Figure 2 shows D for automatically reversing the running direction of the magnetic tape when the end of the magnetic tape being played is detected.
In the control block diagram of the D motor and pinch roller, 20
21 is a system control circuit (hereinafter referred to as SC circuit) that controls the tape drive mechanism, 21 is a supply reel, and -1 is a system control circuit that controls the tape drive mechanism. Tape position calculation circuit, 22
l) D motor M1 based on the command of the SC circuit 2u
．． and a motor drive circuit that controls forward and reverse rotation of M2, 23
1 is a pinch roller drive circuit which drives the actuating plates 12 and 13 shown in FIG. 1 which press and release the pinch rollers P, .

Next, the operation of the SC circuit 2u will be explained based on the waveform diagram of FIG.

First, the tape position arithmetic circuit 21 determines the location immediately before the end of the magnetic tape T running in the FWD mode (for example, 10
seconds to 3 minutes) is detected, the reversal preparation signal S,
It is output to the circuit 20, and at the time tl, the pinch roller P2 is separated from the magnetic tape 2, and after 7, the DD Momo-M2 is reversed at the time t2.

1') 1)-E-I M2 is t of the flywheel 10
The direction of rotation is gradually reversed against the applied force, and the pinch roller P2 has already moved away from the magnetic tape T, so at this point the magnetic tape is in the FWD mode by the independent drive of the D motor M. Run with (・ru.

Next, Ig S detected the end of the magnetic tape T.

is 5CIC! When input to the ll path 20, the pinch roller P separates from the magnetic tape T at time 130, and the magnetic tape T becomes m-free. , force (magnetic tape T
Since it is controlled so that it comes into pressure contact with D, it is reversed by 1.
The driving force of the D motor M is eliminated and the magnetic Q-jT runs in the opposite direction. After the pinch ruler P1 is detached, the DD momo-M1 is also driven in the reverse direction, and at least at the time t when the DD momo-M1 reaches the normal rotation speed in the reverse direction, the pinch roller P is controlled to be brought into pressure contact with the magnetic tape T. Suot&'
! , the magnetic tape T is driven by 2-+ Yapstan R
It enters EV mode (reverse running state).

It goes without saying that the direction of rotation of the supply reel and take-up reel is switched between times 13 and 14 when the magnetic tape T is reversed.

As can be understood from the above explanation, the auto-reverse system of this embodiment is configured to control the control signal of the SC circuit 20.
I) Motor Ml, and bin fI: I-LaP.

D f) The drive mechanism consisting of the motor M2 and the pinch roller P2 is controlled at the timing shown in Fig. 3, so the influence of the flywheel with sufficiently large inertia is eliminated. The magnetic tape T can be reversed instantaneously from the time t when the end of the magnetic tape T is detected. This reversal time t3
Since t is related only to the magnetic tape T whose inertia is almost negligible, it can be set to an extremely short time, and the interruption of the auto-reverse sound is minimized.

By the way, the inversion preparation signal S1 and the terminal detected signal S,
When the detection accuracy for the period t1-t3 is not too long, the drive mechanism by the I)D motor M1, which is close to the take-up side, is first put into the reverse state (of course, the Vinci roller P1 is also removed), and then the supply is carried out. A control method that causes the DD motor M2 close to the side to be in a reverse state is also conceivable. In this case, it is necessary to control the magnetic tape T to be driven by the take-up reel and the supply reel during the reversing operation, albeit for a short time.

Although a case has been described in which the magnetic tape T is run in reverse at the end of the tape, the reverse system of the present invention can also be used for repeat operations in which the magnetic tape T is run in the reverse direction and further in the forward direction. In this case, the tape position calculation circuit 21 outputs a signal S1 that detects the position immediately before the start end of the magnetic tape T, inputs the start end of the magnetic tape T as a signal S2 to the SC circuit 20, and then It would be better to control the operation order so that it is reversed.

As explained above, in the reverse system of the two-capstan deck of the present invention, the first and second I) D constituting the first and second tape drive mechanisms can also change the running direction of the tape in a short time. This is especially effective when parsing the tape at the end of the tape.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a two-cabin stun force type tape recorder tape drive unit driven by two DD motors, and Fig. 2 is an embodiment of the reverse method of the present invention when running the magnetic tape in reverse at the end. Block circuit diagram showing an example, Part 3
The figure is a main waveform diagram of the boot circuit diagram of FIG. 2. In the figure, 20 is an 801gl path, 21 is a tape position calculation circuit, 22 is a motor drive circuit, 23 is a pinch p-ra drive circuit, M, , P are a DD motor and a pinch roller serving as a first tape drive mechanism, M2. P indicates a DD motor and pinch ruler serving as a second tape drive mechanism, and ■ indicates a magnetic tape. Figure 3Figure 2

Claims (1)

[Claims] In a two-capstan type tape recorder in which a magnetic tape is run by first and second drive mechanisms constituted by Ml and a second motor, when the running direction of the magnetic tape is reversed, the first drive The first motor is driven in the reverse direction at the same time as the mechanism is released from the magnetic tape, and the second motor is driven in the reverse direction at the same time as the second drive mechanism is released from the magnetic tape. A reverse system for a two-capstan deck, characterized in that after the first drive mechanism is brought into pressure contact with the magnetic tape, the second drive mechanism is controlled so as to come into pressure contact with the magnetic tape.