JPS5917026Y2 - Tape winding device for cassette type tape recorder - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a tape winding device for a cassette type tape recorder, and is intended to provide a device that is particularly effective when applied to a tape recorder that pulls out the tape from the cassette. be.

A tape recorder that pulls out a tape from a cassette to perform recording or playback operations must wind the tape into the cassette when the tape is switched from an operating state to a stopped state.

One method of winding the tape into this cassette is to use the inertial force of an electric motor that drives the reel shaft on the take-up side, but with this method, the tape is reliably rolled by fluctuations in the load applied to the reel shaft. It may not be possible to wind the tape into the cassette, and if the stop operation is performed in the paused state, the driving force to the reel shaft has been released, so it is impossible to wind the tape using this method. It is possible.

Therefore, in such a system, it is necessary to prevent the stop operation from being performed during the temporary stop operation, or to return the drive mechanism to the reel shaft to the operating state when switching to the stop operation, to avoid complicating the structure. I can't do that.

In addition, the above-mentioned method utilizes the inertia of the motor, or as a more developed method, a capacitor is connected to the drive circuit of the motor, and the discharge current of the capacitor is supplied to the motor. There is something that drives it.

Although such a method is superior to a method that utilizes the inertia of an electric motor, it has the following drawbacks.

In other words, when a tape recorder is configured to use a logic circuit to switch operations, when a stop operation is performed, the logic circuit is immediately reset, so the tape recorder is stopped and the capacitor is discharged. There is no problem because the electric motor can be started for a short time to reliably wind the tape into the cassette, but for example, if the power switch that supplies power to the tape recorder is opened during playback or a power outage occurs, the power supply may be interrupted. When the voltage is cut off, the supply voltage from the constant voltage power supply circuit that supplies power to the logic circuit etc. gradually decreases, so the logic circuit is not immediately reset to a stopped state, but the supply voltage drops to a certain value. The playback operation is canceled for the first time, but at this time the charging voltage of the capacitor has also dropped, making it impossible to reliably wind the tape into the cassette.

The present invention aims to provide a device that eliminates the above-mentioned drawbacks, and will be described in detail below with reference to the drawings.

1 is a terminal connected to the commercial power supply; 2 is a power switch connected to the primary side of the power transformer 3, and has the function of controlling the power supply to the tape recorder; 4 is the secondary terminal of the power transformer 3; This is a smoothing rectifier circuit connected to the side, and is composed of a first diode 5 and a first capacitor 6.

A second capacitor 7 is charged through a second diode 8 by the current supplied from the rectifier circuit 4, and has a larger capacity than the first capacitor 6.

9 has a base connected to the anode side of the second diode 8 via a resistor 10, and a collector connected to the cathode side of the second diode 8 via a resistor 11;
It is also a first transistor whose emitter is grounded.

12 is a second transistor whose base is connected to the collector of the first transistor 9 and whose emitter is grounded, and whose collector is connected to a diode 13.1.
4 to a reset terminal of a logic circuit 15 for switching the operation of the tape recorder, and to one end of an electric motor 16 for driving a take-up reel shaft.

The other terminal of the action machine 16 is connected to a power source, and a transistor 17 for controlling the rotational operation of the electric motor 16 is connected to the ground side.

A control signal obtained from the logic circuit 15 is applied to the base of the transistor 17, and the transistor 17 becomes conductive in accordance with each operation of the tape recorder.

Reference numeral 18 denotes a constant voltage power supply circuit that supplies power to the logic circuit 15, motor 16, amplifier circuit (not shown), etc., and its supply voltage is equal to the voltage across the first capacitor 6 constituting the smoothing rectifier circuit 4. It is configured to descend more slowly than the descent.

Further, a discharge resistor 19 is provided at both ends of the first capacitor 6.
is connected.

The present invention is constructed as described above, and its operation will be explained next.

In the illustrated state, when the power switch 2 is closed, the stepped-down AC power is output to the secondary side of the power transformer 3 and rectified by the first diode 5.

As a result, the first capacitor 6 and the second capacitor 7 are charged, and the constant voltage power supply circuit 18 operates to supply constant voltage power to the logic circuit 15 and the like.

In this state, the first transistor 9 is in a conductive state and the second transistor 12 is kept in a non-conductive state, so that the operations of the logic circuit 15 and the motor 16 are not affected in any way.

When operations such as playback, fast forwarding, and rewinding are performed in such a state, the logic circuit 15 outputs a control signal corresponding to each operation, and an electric motor 16 and a plunger (not shown) for switching the drive mechanism are required for each operation. Each operating state of the tape recorder is configured by performing various operations.

Next, a case will be described in which the power supply is cut off due to a power failure or opening of the power switch 2 while the cheese recorder is performing a playback operation, for example.

When the power supply is cut off, the charge stored in the first capacitor 6 is discharged through the discharging resistor 19 and the first transistor 9, and when the voltage across the first capacitor 6 becomes less than a certain value, the first transistor 9 is reversed to non-conducting state.

Also, at this time, the second diode 8 prevents the second diode 8 from discharging the charges stored in the second capacitor 7, which has a larger capacity than the first capacitor 6, so the voltage across the second capacitor 7 is in a high state. Retained.

Therefore, when the first transistor 9 is reversed to a non-conductive state, its collector potential, that is, the base potential of the second transistor 12 increases, so that the second Herlan sister 12 remains conductive until the charge in the second capacitor 7 is discharged. become a state.

When the second transistor 12 is inverted to a conductive state, its collector is connected to the reset terminal of the logic circuit 15 and the motor 16.
The logic circuit 15 connected to the ground side of the 21st run sister 12 is reset and the drive mechanism of the tape recorder is returned to the stopped state, and the 21st run sister 12 becomes conductive, causing the 21st run sister 17 to become non-conductive. The electric motor 16 continues to rotate.

As a result, the magnetic tape pulled out from the cassette is reliably wound into the cassette by driving the take-up reel shaft by the rotation of the electric motor 16.

In addition, the drive of the take-up reel shaft by the electric motor 16 in the present invention is performed by a direct drive or an oscillating mechanism, and the brake mechanism of the reel shaft is a small one on the reel shaft that performs rotational drive in the stopped state, that is, the take-up reel shaft. A braking force is applied, and a large braking force is applied to the supply reel shaft, which is a driven shaft.

As explained above, in the present invention, when the power supply is cut off due to a power failure or opening of the power switch while the tape recorder is in an operating state, the logic circuit is reset, the tape recorder is stopped, and the electric motor is turned off for a short time. Since the take-up reel shaft was rotated during that time, the magnetic tape could be reliably wound into the cassette, and in particular the magnetic tape could be pulled out from the cassette and used. This is extremely effective when applied to a tape recorder.

[Brief explanation of the drawing]

The illustrated circuit is an embodiment of the tape winding device of the present invention. Explanation of main figure numbers, 2... Power switch, 3... Power transistor, 4... Smoothing rectifier circuit, 5... First diode, 6... First condenser, 7... First 2
Condenser 8...Second diode, 9...First transistor, 12...Second transistor, 1
5... Logic circuit, 16... Electric motor, 18... Constant voltage power supply circuit.

Claims (1)

[Scope of utility model registration request] A smoothing rectifier circuit consisting of a power supply 1 with a power switch connected to the primary side and a second diode and a first capacitor connected to the secondary side of the lance, and a current rectified by the smoothing rectifier circuit that connects the second diode a second capacitor having a larger capacitance than the first capacitor, the base of which is connected to the anode side of the second diode, and the collector of which is connected to the cathode side of the second diode. a first transistor; a logic circuit that outputs a control signal in accordance with an operation switching operation of the tape recorder; a base is connected to the collector of the first transistor; and the collector is connected to a reset terminal of the logic circuit and a a second transistor connected to a drive circuit of a motor that drives the reel shaft, and when the power supply to the power transformer is cut off, the second transistor is made conductive by the discharge current of the second capacitor; A tape winding device for a cassette type tape recorder, characterized in that the logic circuit is reset to bring the tape recorder to a stopped state, and the electric motor is rotated for a short time to drive the take-up reel shaft during that time. Including device.