JPS631654B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a constant speed tape running device in a tape recorder, and in particular, in order to automatically and accurately stop the tape at a predetermined value position of a tape counter, the present invention relates to a constant speed tape running device for a tape recorder. This is suitable for slowly moving the tape (running at a constant speed).

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a part of the reel drive system of a reel-to-reel tape recorder, a part of the control system in the drive system, and a tape running position display system. Omitted for clarity. In the figure,
1 is a reel on the feeding side, and 2 is a reel on the winding side. As is well known, these are respectively attached to a reel shaft 3 on the feeding side and a reel shaft 4 on the winding side.
These reel shafts 3 and 4 are coupled to reel motors 5 and 6, respectively, as is well known. Drive current is selectively supplied to the motors 5 and 6 from a well-known commercial power source 7 via a switch 8 and a contact 9, which will be described later, by a rewind/fast-forward changeover switch 10.
That is, when the switch 8 is closed and the switch 10 is in the position shown by the solid line, a drive current is supplied from the power source 7 to the motor 5 via the resistor R, the reel 1 is rotated, and the tape is rewound as is well known. When the switch 10 is on the broken line side, the motor 6
A drive current is supplied to the tape, and the tape is fast-forwarded in a well-known manner. Furthermore, when the tape is run at a constant speed by a capstan and pinch rollers (not shown), drive currents are supplied to the motor 6 for winding and for back tension to the motor 5, as is well known, but the circuit for this purpose is Omitted. Incidentally, a chain line 11 indicates a well-known part.

A pulley 12 is fixed to the reel shaft 3, and a disc 14 is rotated by the pulley via a belt 13. A light source 15 and a light-receiving element 16 are arranged sandwiching this disc 14, and the light from the light source 15 is transmitted to the disc 14.
The light receiving element 16 is reached through the notch 17 .

Due to the rotation of the reel shaft 3, the light receiving element 1
6 provides a pulse per revolution, which is supplied to a counter 18 and a frequency/voltage converter 19. The counter 18 counts the pulses and displays a numerical value corresponding to this count value on a well-known display device 20 consisting of a 7-segment LED. Further, pulses are obtained from the counter 18 when the display device displays "0029", "0009" or "0000", and these pulses are supplied to flip-flops 21 and 22 and a not circuit 23, respectively. . When the state of the flip-flop 21 or 22 is reversed by these pulses, the relay 26 is energized via the amplifier 24 or 25, and the contact 9 of the relay is switched to the dashed line side.
Contact 27 is closed. In this state, the switch circuit 28, which is configured by a triac, for example,
A power supply circuit is formed from the power source 7 to the motors 5 and 6 via the motor 29 and resistors R1 and R2.

30 is a reference voltage generator, the reference voltage of the generator and the voltage converted by the frequency/voltage converter 19 are compared by a comparator 31, and the output voltage of the converter 19 is lower than the reference voltage. Sometimes the switch circuit 2 is connected to the switch circuit 2 via the buffer amplifier 32.
8 is turned off, and the switch circuit 29 is turned on via the NOT circuit 33, and driving power is supplied from the power supply 7 to the motor 5 via the switch 8, the contact 27, the switch circuit 29, the resistor _R2 , and the contact 9. is,
The tape is rewound. When the voltage of the converter 19 becomes higher than the reference voltage, the switch circuit 28
is turned on, and the switch circuit 29 is turned off, a driving current is supplied from the power supply 7 to the motor 6, and the tape being rewound is braked.

The output of the flip-flop 22 is also supplied to a reference voltage generator 30, whereby the reference voltage is controlled to be low.

The switch 34 is for switching the reel diameter between 7'' and 10'' and is operated manually, with the solid line side being 10'' and the broken line side being 7''. This switch 34
When switched to the 7'' side, the output side of the flip-flop 21 is grounded and no output is obtained from the amplifier 24, and the reference voltage of the reference voltage generator 30 is controlled via the NOT circuit 35 to be at a medium level. .

What is shown within the chain line 36 is a well-known example, which shows an amplifier 37 to which the output of the NOT circuit 23 is supplied, a relay 38 that is energized by the output of the amplifier, and a relay 38 that is energized via a contact 39 of the relay. It consists of an electromagnetic plunger 40 which is sometimes energized and releases the braking applied by a well-known band brake (not shown) on the reel shafts 3, 4. 41 is a power supply terminal of the plunger 40, and the switch 8 is constituted by a contact point of a relay 38. relay 3
8 is energized as is well known while the tape is running, and the contact 39 and switch 8 are turned on, but when the counter 18 displays "0000", the power is deenergized, and the motors 5 and 6 from the power supply 7 are turned off. The power supply current is cut off, and the reel shafts 3 and 4 are braked by the band brake.

In the tape recorder having the above-mentioned configuration, the display of the counter 18 is set to zero as well known, and then the tape is run at a constant speed as well known to play back the audio, and the above playback is started at an appropriate point. This is effective for rewinding the tape up to That is,
In FIG. 2, which shows the rotational speed of the reel shaft 3 relative to the display on the counter 18, it is assumed that the rotational speed of the reel shaft 3 has reached its maximum value due to tape rewinding, as shown by a. This rotational speed is converted into a frequency by the light receiving element 16, and this is converted into a frequency by the converter 1.
9 into a voltage, which is sufficiently higher than the reference voltage and therefore the switch circuit 28
is on and 29 is off. Due to this rewinding, when the display on the counter 18 becomes "0029",
By energizing the relay 26 via the flip-flop 21 and amplifier 24, its contacts 9 and 27 are switched as described above, and a drive current is supplied to the motor 6 via the switch circuit 28 which is turned on, and the tape is wound. The return speed decreases rapidly as shown in FIG. 2b. As a result, the reel shaft 3 as shown in c.
As the rotation of the converter 19 decreases, the output voltage of the converter 19 becomes approximately equal to the reference voltage, and the slight difference in these voltages causes the switch circuits 28 and 29 to alternately turn on and off, causing the motors 5 and 6 to alternately turn on and off. When driven, the rotational speed of the reel shaft 3 becomes approximately constant as shown in FIG. 2d, and the speed of the tape also becomes approximately constant (second speed), although there is an error due to the tape winding diameter.
When the display on the counter 18 becomes "0009" during this approximately constant rewinding, the reference voltage becomes lower than the output of the flip-flop 22, the switch circuit 28 is turned on again, and power supply current is supplied to the motor 6. As shown in FIG. 2e, the rotation of the reel shaft 3 becomes even slower. When the rotation of the reel shaft 3 becomes low as shown in FIG. As a result, the speed becomes approximately constant as shown in FIG. 2g, and the speed of the tape also becomes approximately constant (first speed).

When the display on the counter 18 reaches "0000" in this state, the relay 38 is deenergized as described above, the power supply current to the motors 5 and 6 is interrupted by the switch 8 being turned off, and the plunger 40 is deenergized.
The reel shafts 3 and 4 are braked by the band brake, and the reels 1 and 2 are stopped instantaneously as shown in FIG. 2h, and the tape is stopped when the counter 18 shows "0000".

The above explanation is for a case where the display "0029" is detected after the rotation of the reel shaft 3 reaches the maximum speed, but as shown in FIG. If the display "0029" is detected before reaching , the relay 26 is energized, but
Since the switch circuit 28 is off and the switch circuit 29 is on, a drive current flows to the motor 5, and the rotational speed of the reel shaft 3 further increases. In this way, reel shaft 3
When the rotation slows down and reaches the second speed, the motors 5 and 6 are turned on and off alternately as described above, and the speed becomes approximately constant as shown in FIG. , e, f, g, and h, the tape stops at the "0000" position.

Further, as shown in FIG. 2k, if the second speed is not reached before the display "0009" is detected, the state of the flip-flop 22 is reversed by the detection of "0009", thereby causing the The reference voltage becomes low and the relay 26 is connected via the amplifier 25.
is excited, a power supply current is supplied to the motor 6, and the rotational speed of the reel shaft 3 becomes low as shown in FIG. 2l, and is rotated at a constant speed at a first speed shown in FIG. 2m. Thereafter, the tape passes through the paths shown in FIG. 2g and h and stops at the display "0000" as described above.

As shown in FIG. is supplied, and when the first speed is reached, the speed becomes approximately constant as shown at o in FIG. Thereafter, after passing through steps g and h in Figure 2, the tape stops at the display "0000".

As shown in FIG. 2p, if the display "0000" is detected before the rotational speed of the reel shaft 3 reaches the first speed, the relay 38 is deenergized and the tape stops instantly.

In the above embodiment, the running of the tape during rewinding is electromagnetically braked by supplying a drive current to the motor 6, but an eddy current brake or the like may also be used as the electromagnetic brake.

The above description is based on the case where 10'' reels are used as reels 1 and 2, but when using 7'' reels, the switch 34 is switched to the dashed line side. As a result, even if the display "0029" is detected, the relay 26 is not energized, and the reference voltage is also switched to the second
After passing through q, r, s, and t in the diagram, the tape stops at the display "0000".

In the above description, the case where the playback stops at "0000" has been explained, but the present invention can also be applied to a tape recorder that plays back at "0000".

As described above, the present invention has a first motor 5 that applies a driving force in the rewinding direction to the reel 1 on the feeding side, and a second motor 5 that applies a driving force in the winding direction to the reel 2 on the winding side. The motor 6 has its respective drive current input terminals connected in series, and the two triaxes 2
Current control elements such as 8 and 29 are connected in parallel with their current passing terminals connected in series, and a power source such as a commercial power source 7 is connected to both ends of the current control elements.
A light source 15, a light receiving element 16, and a frequency/voltage converter sandwiching a disc 14 provided with a notch 17 to generate a rotational speed voltage corresponding to the rotational speed of the reels 5, 6 on the feeding side or winding side. 19, etc., and compares the speed voltage with a reference voltage set by a reference voltage generator 30, generates a comparison output according to the magnitude relationship between them, and outputs the comparison output to the above-mentioned triacs 28, 29, etc. current control element 2
In a tape recorder equipped with a comparator 31 that inputs input to each control input terminal, the conduction states of the two current control elements such as the triaxes 28 and 29 are reversed in response to the comparison output, that is, Since the two current control elements such as the triacs 28 and 29 are connected to the comparison outputs inputted to their control signal input terminals so that when one becomes conductive, the other becomes non-conductive, this is necessary. The tape can be run at a predetermined speed according to the

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is a graph showing the operation of the one shown in FIG. 1, 2: reel, 5, 6: motor, 33: not
circuit.

Claims (1)

[Claims] 1 A first motor that applies a driving force in the rewinding direction to the reel on the feeding side and a second motor that applies a driving force in the winding direction to the reel on the winding side are connected in series with their respective drive current input terminals. one in which two current control elements have their current passing terminals connected in series, one in which a power supply is connected to both ends of the two, and one in which a power supply is connected to both ends of the reel on the feeding side or winding side. A speed voltage generating means that generates a rotational speed voltage according to the rotational speed, a speed voltage generating means that compares the speed voltage with a separately set reference voltage, generates a comparison output according to the magnitude relationship between them, and transmits the comparison output to the current control element 2. In a tape recorder equipped with a comparator that inputs input to each control input terminal, the conduction states of the two current control elements are opposite to each other in response to the comparison output, that is, when one conducts, the other A constant speed tape running device for a tape recorder, characterized in that the two current control elements and the comparison output inputted to their control signal input terminals are connected so as to be non-conductive.