JPS5911507A - Muting device for tape drive reversing mechanism - Google Patents

Abstract

PURPOSE:To prevent the generation of abnormal sound and the missing of reproduced sound at tape reversing, by adjusting the operating time of muting in respone to a time required for the reversing of the tape, in a reversing type tape player of automatic return type. CONSTITUTION:A tape end detecting circuit 1 is connected to a tape drive reversing mechanism 2 and to a set side input terminal of an SR type flip-flop circuit 3. An output terminal of the flip-flop 3 is connected to a muting circuit 4 blocking sound production from a speaker. A delay circuit 10 is inserted so that an operating end detecting switch 5 of the tape drive reversing mechanism resets the muting circuit with some margin after the end of operation of the tape drive reversing mechanism is detected, and the delay time by this delay circuit 11 is preferably about 5-10% of the tape drive reversing mechanism operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a reversing type tape player, generally called an auto-return type, and in particular, its tape drive reversing mechanism and micoating device are interlocked to control the tape running direction. To provide a tape player which prevents abnormal noise from being generated from a speaker when reversing the tape.

[Technical Background of the Invention A co-auto return type tape player is
For example) When the tape reaches the end while playing by running the tape on the Δ word side, the tape end detection mechanism detects each end, and based on the command from this detection mechanism, the tape drive is reversed. This prevents the mechanism from operating. With this tape drive reversal mechanism, the driving force of the motor is switched from the forward side capstan shaft to the reverse side capstan shaft, and the pinch roller for pressing the tape against the capstan shaft is also switched from the forward side to the reverse side. The running direction of the tape is reversed to the Rivas side.

By the way, this type of tape reversal operation is performed in such a way that playback can be continued immediately after reversal (this is done while the tape and head are in contact with each other), so if the tape moves irregularly due to stopping or reversing, The head picks up the above signal, which is heard as abnormal noise from the speaker.For this reason, in the past, a tape drive reversing mechanism and a muting device were linked to prevent the tape from reaching its end. Since then, a muting device has been activated for a certain period of time to block the sound being played from the speakers.

[Problems with backlash technology] However, in conventional tape players, the micoating device was simply set to operate for a certain period of time, so it was not possible to use tape players like car stereos. The Tape Play A7, which is used under harsh conditions, has the following disadvantages.

In other words, when using a battery as a power source like Car Stereo A, it is inevitable that the power supply voltage will drop and fluctuate, but when such a voltage drop occurs, the response of the motor 9J plunger used as the drive source for the tape drive reversing mechanism will be affected. Sexuality decreases,
That's c) It will take time to reverse. especially,
Recently, as the tape player A7 has become smaller and lighter, a motor is used as the drive source for the tape drive reversing mechanism, and the connection between the motor and the tape drive reversing mechanism is made by a small plunger that is activated by a command from the tape end detection mechanism. control l'
A 1J tape player 17 is used, but in this type of tape player, a drop in power supply voltage directly affects the performance of the motor, causing an increase in the tape reversal time. .

Also, car stereos, etc. installed in vehicles that are left outdoors are exposed to sub-zero temperatures in the winter, but in such low temperatures, the lubricant used in each part of the tape player The viscosity of the tape player decreases, making it difficult for the various parts of the tape player to operate smoothly. Therefore, even if the tape drive reversing mechanism operates, resistance is generated in the operation of each member, and the time required to reverse the tape increases accordingly.

Due to such a drop in power supply voltage or a drop in ambient temperature,
In conventional tape players, where the muting device is activated only for a predetermined period of time when the tape is turned over for a long time, the muting time becomes insufficient and an abnormal noise is emitted from the speakers at the start of tape running. Met.

Of course, it is possible to set the muting time longer to take into account the reversal time delay, but in that case, the muting time becomes too long during normal operation of the tape player, and the beginning of the reversed tape This was not a realistic countermeasure because there was a risk that the playback sound would be skipped.

[Object of the Invention] The present invention was proposed to improve the above-mentioned drawbacks of the conventional tape player 47, and its purpose is to adjust the operating time of the micoating device according to the time required for reversing the tape. It is an object of the present invention to provide a muting device for a tape drive reversing mechanism which prevents generation of abnormal noise and omission of reproduced sound when reversing the tape.

[Summary of the Invention] Muting of the tape drive reversing mechanism of the present invention involves connecting a tape end detection circuit to the tape drive reversing mechanism and to the muting circuit, and activating the muting circuit simultaneously with the start of reversing the tape. A switch for detecting the completion of operation of the tape drive reversing mechanism is connected to a signal matching circuit via a latch circuit, and the detection switch is directly connected to the signal matching circuit in parallel with the latch circuit to control the signal matching circuit. Then, the open/close state of the switch arranged in the latch circuit is compared before and after the tape reversing operation is completed, and the completion of the operation of the tape drive reversing mechanism due to switching of the switch is detected, and the operation of the micoating circuit is stopped. This is what I did.

“Embodiment of the Invention” An embodiment of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a block diagram of this embodiment.

In FIG. 1, a tape end detection circuit 1 is connected to a tape drive reversing mechanism 2, and is also connected to an input terminal of an SR type flip-flop circuit 3 on the cell side 1. The output terminal of this flip-flop circuit 3 is connected to a muting circuit 4 that blocks sound from the speaker.

Here, the tape end detection circuit 1 detects when the tape tension changes or the rotation of the reel base stops, and detects that the tape has reached its end. Use something that sends a signal.

Further, the tape drive reversing mechanism 2 moves the change play 1 by using the driving force of a motor or the suction force of an electromagnetic plunger based on a command from the tape xr-end detection circuit 1. That is, FIG. 2 does not show an example of this tape drive reversing mechanism 2, in which 20a and 20b are capstan shafts on the forward side and the reverse side, 218 and 21b.
are pinch rollers rotating in pressure contact with the capstan shafts 20a and 20b, 22a and 22b are pinch rollers 21a,
There is a holding frame 21b. These holding frames 22a and 22b are
Tapered cam 24 installed on change plate 23
a and 24b, and as the pinch roller 23 moves to the change play 1, one of the pinch rollers comes into contact with the capstan shaft. Further, the change plays 1 and 23 are engaged with the switching bin 25 at one end, and the switching bin 25 is connected to the tape end detection circuit 1.
Based on the command, the change plays i to 23 are moved in the direction A or B in the figure by being moved by a motor or an electromagnetic plunger. And this change plate 2
An actuator 26 is provided at the end of 3! -J, this actuating piece 2
An operation completion detection switch 5 for the tape drive reversing mechanism is provided opposite to the tape drive reversing mechanism.

The operation completion detection switch 5 of this tape drive reversing mechanism is
As shown in FIG. 1, the tape end detection circuit 1 is connected to the latch circuit 7 via the terminal 6, and the latch circuit 7 is connected to the signal matching circuit 8. is directly connected to the signal matching circuit 8 via a NOT gate 9 which is a signal inversion means arranged in parallel with the latch circuit 7.
is connected to the reset side input terminal of the flip-flop circuit 4 via a NOT gate 10 and a delay circuit 11.

a3. Here, the delay circuit 10 is inserted so that the micoding circuit is reset after some time has passed after the detection switch 5 detects the completion of the operation of the tape drive reversing mechanism. The delay time caused by this circuit 11 is preferably about 5 to 10% of the operation of the tape drive reversing mechanism.

The micoating device of this embodiment has the structure as described above, and its operation will be explained next.

For example, when the tape is traveling toward the A word side, the operating piece 25 of the change plate 23 and the detection switch 5 are in contact, so the detection switch 5 is in an open state. Now, when the tape reaches the end,
The tape end detection circuit 1 detects this, and the signal is transmitted to the tape drive reversing mechanism 2.
starts operating. At the same time, the signal from the tape end detection circuit 1 is input to the set side of the flip-flop circuit 3, so the muting circuit 4 is activated to continuously cut off the abnormal noise from the speaker during the reversing operation. Further, the signal from the tape-■nd detection circuit 1 is sent to the gate 6, and since this gate 6 is listened to, the open/closed state (in this case, open) of the detection switch 5 is input to the latch circuit 7, and the tape running state is input to the latch circuit 7. The direction you were in will be remembered.

When the tape drive and reversing machine 4ft2 successfully reverses the tape in the running direction, the detection switch 5 is switched to the closed state. Then, this closed state and the output from the 4T detection switch 5 are inverted by the NOT gate 9 and input to the signal matching circuit 8 as an open state signal, so that they match the open state signal from the latch circuit 7. , the output signal from the signal matching circuit 8 is at L level 4T. This L level signal is inverted to an H level signal by the No king gate 10, and is delayed in the delay circuit 11 by an amount equivalent to the rising edge of tape running or a time considering a predetermined margin. Input to reset insertion horn terminal. As a result, the flip-flop circuit 3 is re-hit, the mi]-teng circuit 4 is activated and 'K<' is reached, and the reproduced sound is heard from the speaker.

Next, due to the effect of power supply voltage and decrease in ambient temperature,
If the tape drive reversing mechanism takes enough time to complete its operation, the detection switch 5 is switched back to the same open state as before the reversal. Therefore, the input signal in the closed state from the detection switch 5 that is inverted by the NOT gate 9 and the input signal in the open state stored in the latch circuit do not match in the signal matching circuit 8. Therefore, a 1-level signal is connected and output from the signal matching circuit 8, and this 1-level signal is inverted to an L level signal by the NOT gate 10, and is input to the reset [- side of the Noritsubu flop circuit 3. Therefore, the muting circuit 4 continues to operate. As a result, the noise from the speaker is continuously cut off by the micoating circuit 4 until the detection switch 5 is switched due to the completion of the operation of the tape drive reversing mechanism.

J3, the present invention is not limited to the illustrated embodiment, but in detecting the completion of the operation of the tape drive reversing mechanism,
If the detection switch 5 does not require a margin,
Delay circuit 11 is not necessary.

Further, the NOT gate 9 provided before the signal matching circuit may be provided not on the detection switch 5 side but after the latch circuit. Furthermore, the detection switch 5 may be one that is operated by the change plate 23, but may also be one that senses the start of reversal of the tape itself or the reel base, and thereby detects the completion of the operation of the tape drive reversal mechanism.

[Effects of the Invention] As described above, according to the present invention, even if it takes time to reverse the tape due to a drop in the power supply voltage or other causes, no abnormal noise is generated from the speaker and the reversal is possible. To provide a muting device for a tape drive reversing mechanism that does not cause the reproduction sound of the rising part of the tape to be missing even when the tape is completed early.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the micoating device of the tape drive reversing mechanism according to the present invention.
The figure is a plan view of the change plate portion that is inserted into the muting device of FIG. 1. DESCRIPTION OF SYMBOLS 1... Tape end detection circuit, 2... Tape drive reversing mechanism, 3... Flip-flop circuit, 4... Micoating circuit, 5... Operation completion detection switch of tape drive reversing mechanism, 6...・Gate, 7...Latch circuit,
8... Signal matching circuit, 9, 10... NOT gate,
11...Delay circuit, 20a, 20b...Capstan shaft, 21a, 21b...Pinch roller, 22a,
22b... Holding frame, 23... Change play 1-1
24a, 24b... Taper cam, 25... Switching bin, 26... Operating piece.

Claims (3)

[Claims] (1) A tape end detection circuit is connected to the tape drive reversing mechanism and the muting circuit, which start operating in response to a command from the tape end detection circuit, and a switch for detecting the completion of operation of the tape drive reversing mechanism is connected to the tape end detection circuit. The detection switch is connected to the signal matching circuit via a latch circuit operated by a command from the detection circuit, and the detection switch is directly connected to the signal matching circuit in parallel with the latch circuit, and one of the circuits connected in parallel to the signal matching circuit. A tape drive reversing mechanism characterized in that the signal matching circuit is further provided with a signal inverting means, and the signal matching circuit is connected to the muting circuit, so that the operation of the muting circuit is canceled by a command from the signal matching circuit. muting device. (2) The micoating device for a tape drive reversing mechanism according to claim 1, wherein the switch for detecting the completion of operation of the tape drive reversing mechanism is operated by a change plate. (3) A micoating device for a tape drive reversing mechanism according to claim 1 or 2, wherein the signal matching circuit has a delay circuit at a subsequent stage.