DE2925304A1 - METHOD AND DEVICE FOR EFFECTING THE FAST RETURN OF THE TAPE IN A TAPE RECORDING AND PLAYBACK DEVICE - Google Patents

Description

SB7P-1976

Method and apparatus for effecting fast rewinding of the tape in a tape recorder and player.

The invention relates to a method and a device for triggering the fast rewind of a tape in a tape recording and playback device by the tape in front and Return direction is transportable and that a fast forward mechanism includes.

For tape recording and playback devices, it is known that Measures must be provided in order to be able to transport the tape quickly in the forward and reverse directions. So that's supposed to Finding a specific point on the tape can be made easier.

For tape devices where the tape operated in both directions can be, a fast tape feed can easily be achieved by a mechanism if the tape is in both transport directions runs in the normal forward direction. For this purpose, only the pressure roller needs to be lifted off the capstan with which the fast forward of the tape sets itself.

By

909881/0838

SB7P-1976

When the pressure roller is lifted off the capstan, the grinding friction clutch of the belt disk engages and causes the fast forward,

For fast rewinding of the tape there is usually a special one Mechanism is provided which is very complex and on the one hand the pressure roller out of engagement with the capstan and on the other hand, disengages the winding wheel from the tape transport mechanism. At the same time, the unwinding side Belt drive driven to effect fast reverse. The transport direction of the belt is switched over usually with the help of a relay.

The invention is based on the object of a method for driving of tape recorders and players, as well as a To provide a device with which complicated mechanisms for the fast rewinding of the tape eliminated and thus such Devices can be set up more easily and economically.

The procedure for solving this problem consists of the following steps:

A first change in the direction of transport of the tape is effected;

A fast forward movement of the tape is then effected; and after that there will be a second change in the direction of transport of the tape causes.

The device for carrying out the method provides that a manual control allows the setting of the fast forward, that the hand control includes a short-time switch that

while

90 9 881/0838

SB7P-1976

briefly during the switchover to and from the return position an electrical contact closes, via which the reversal of the transport direction of the tape is controlled,

The advantages and features of the invention also emerge from the following description of an exemplary embodiment in conjunction with the claims and the drawing. It shows:

Fig. 1 is a block diagram of the electronic

System according to the invention;

Figure 2 is a circuit diagram of the electronic system

according to FIG. 1.

The electronic system of Fig. 1 comprises a detector 1, with the rotation of the tape receiving disc or the Belt plate 20 is determined, which carries the winding core. This detector 1 gives on the output side depending on the state of rest or movement of the belt plate 20 a logic signal level 0 or 1 from. A first logic level 2 delivers on the output side Logical signal level 1 or 0, depending on whether the belt platter 20 is stopped from the rotating state or when it is stationary Disk stopped. A monostable multivibrator 3 speaks to the output signals of the first logical Stage 2 on and in turn supplies a pulse at the output for each transition from signal level 1 on the input side to signal level 0, which controls a relay Rl for reversing the transport direction of the tape via a buffer transistor 21. This changeover relay Rl reacts to every control pulse that causes a reversal of the transport direction of the tape.

909881/0838

SB7P-1976

Two switches Sl and S2 are assigned to the positioning of the cassette, the switch S2 is closed with the beginning of the insertion of the cassette and causes the relay Rl to be energized. In contrast, the switch S1 is closed as soon as the cassette assumes the operating state in order to excite a Motor 22 to trigger.

With a lamp 23, which is connected to the output of the detector 1 the correct advance of the tape is displayed.

With a manual control 4, the fast forward movement of the tape can be set by lifting the pressure roller off the capstan will. A temporary switch S4 is coupled to this mechanical control. This switch temporarily sets ground potential on conductor 24 when the hand control is moved to the fast reverse position. Furthermore is a Switch S3 is available, which is also mechanically connected to the hand control and with the actuation of the hand control is also operated.

The electronic system works as follows: When the cassette is inserted, switch S 2 is closed and the switching relay Rl energized. At the output of the detector 1, the signal level is 0, while the output signal is the logical Level 2 corresponds to the signal level 0, since the switch Sl is open. The motor 22 is not energized in this state, i.e. the Belt plate 20 is still held, so that the logic signal level 0 is effective at the output of the monostable multivibrator 3 is. In this state the relay Rl remains energized.

As soon

909881/0838

SB7P-1976

As soon as the cassette is in its operative position, the Switch Sl closed and the motor 22 set in motion. Thus, the output signal from detector 1 takes the logical one Signal level 1 on, while the output signal of the logic level remains at signal level 0 because switch S2 is closed is.

In the circuit after logic level 2, everything remains unchanged, so that the cassette is played according to program I. At the end of the program, the tape of the cassette reaches the end position and the belt plate 20 stops. This increases the output signal of the detector 1, the logic signal level 0 and since the switch S1 is closed and thus the voltage VB2 different from 0 is, the output signal of logic level 2 also changes and assumes signal level 1. This is the monostable Multivibrator 3 triggers an output pulse which causes the switching relay Rl to drop out and thus the return of the tape triggers.

The engine continues to run in the meantime, causing program II to run.

At the end of program II, the belt plate 20 becomes the second Times stopped and from the monostable. Multivibrator 3 one pulse for the triggering of a renewed drop in excitation for the changeover relay Rl supplied. In this control mode, the The cassette is played continuously forwards and backwards, i.e. programs I and II are repeated continuously.

To change the program control it is necessary to change the

Hand control

9 0 9881/0838

SB7P-1976

To operate manual control 4 again, which closes switch S3 and the multivibrator 3 supplies a pulse for triggering the drop in excitation at the switching relay Rl to to reverse the direction of transport of the tape.

If you want to set a fast forward, it is necessary to to adjust the manual control 4 counterclockwise in the illustration according to FIG. 1, whereby the pressure roller is lifted off the capstan and the tape is advanced at high speed.

If the fast reverse is to be switched on, the manual control 4 is clockwise in the representation according to FIG. 1 actuated. This mechanically sets the fast forward movement of the tape, with before and after the fast forward movement a reversal of the transport direction of the tape is effected, since when switching through the middle position of the switch S4 via the Line 24 applies ground potential to the monostable multivibrator 3.

This sequence of operations enables the tape to be rewound quickly without mechanical parts having to be provided for fast rewind.

A circuit diagram for the block circuit shown in FIG. 1 is shown in FIG. In detector 1, with which the rotation of the Belt plate is detected, a capacitive sensor 25 is provided, as described in German patent application P 29 06 929. 2 has been described. The circuit contains an oscillator 26, which oscillates at a frequency of about 100 kHz and consists of three NOR-

Gates

909881/0838

SB7P-1976

Gates of the CMOS type is constructed. Furthermore is a first Detector circuit 27 is provided, which detects the modulation impressed by the capacitive sensor. A second detector circuit 28 supplies the logic signal level 1 on the output side, which corresponds to the voltage VB2 if a modulation is present and the logic signal level 0, which corresponds to the ground potential if there is no modulation.

The monostable multivibrator 3 is constructed from a linearly integrated circuit 29 of the 555 type, which is positive on the output side Supplies square-wave pulses, the duration of which is determined by the capacitance of the capacitor 30 connected to pin 6, if there is a negative pulse of any duration at the input »This pulse is received from a differentiation circuit, which is made up of a NAND gate 31 and an RC network consisting of the capacitor 32 and the resistor 33. At the entrance of the NAND gate 31, a positive step voltage is applied.

The line 24 coming from the hand control 4 is connected to the output of the NAND Gatfcer 31, so that when always one the switch in the manual control 4 is closed, a negative pulse is present at the input of the integrated circuit 29. In this way, the monostable multivibrator 3 delivers one each time one of the switches S3 or S4 of the manual control 4 is closed Control pulse to the changeover relay Rl.

When the device is in operation, switch S2 is closed when the cassette is inserted. Under these conditions Detector 1 and logic level 2 are still there

on the output side

909881/0838

10 SB7P-1976

signal level 0 on the output side. The input of the integrated circuit 29 at pin 2 is at signal level 1, so that the changeover relay Rl is energized.

The motor 22 is stopped because the switch Sl is open and thus the voltage VB2 is not effective.

When the cassette assumes the operating position, the switch S1 is closed, so that the detector 1 at the output the Assumes signal level 1 and signal level 0 is maintained at the output of logic level 2. This also changes all of the Logical stage 2 downstream switching stages do not have their switching state, with the exception of the motor 22, which begins to run since now the supply voltage VB2 is effective. With this the program runs I. At the end of the belt run the exit goes of detector 1 to signal level 0 and switches the output of logic level 2 to signal level 1. The transition from Signal level 0 to signal level 1 at the output of the logic stage causes, as already mentioned, a pulse that excites the Switching relay Rl can drop, the motor 22 remains in the excited state and continues to run.

The drop in excitation of the changeover relay Rl causes the mechanical Ready for tape transport in the opposite direction. When this readiness arises, the belt platter begins 20 to rotate again, so that the output of the detector 1 falls back to the logic signal level 1 and the output logic level 2 assumes signal level 0. The motor remains in the excited state.

In order to

903881/0838

11 SB7P-1976

Program II is now running.

At the end of the belt run, the output of the detector 1 again assumes the logic signal level 0 and triggers at the output of the logic level 2, signal level 1. That way will causes a control pulse for the monostable multivibrator 3, which causes the drop in excitation for the switching relay Rl causes.

When the cassette is moved out of the operating position, the switch S1 opens and causes a transition in the signal level at the output of logic level 2 to signal level 0. This also switches off the excitation of motor 22, since the Switch Sl is opened and the voltage VB2 drops.

When the cassette is removed from the device, the also opens Switch S2, with which the entire circuit falls back into the idle state.

Closing the switch S3 triggers the excitation drop for the switching relay Rl and thus allows the switching of the Direction of transport of the tape by hand.

As already mentioned, in order to trigger the fast rewinding of the tape, the manual control 4 must be operated in such a way that that the switch S4 is pivoted clockwise. This results in the following operating sequence. First of all, it will be briefly the ground potential is applied to the output of the NAND gate 31 and causes the direction of movement to be reversed. The fast forward movement of the tape is then effected mechanically by the

Pressure roller

909881/0838

12 DB7P-1976

The pressure roller is lifted off the capstan. It should be noted that fast forwarding in a direction opposite to playback corresponds to fast rewinding of the tape, with which the desired goal is achieved.

When switch S4 is returned to the central position, This again results in a short-term connection of the line 24 to ground, which means the transport direction of the tape for the second time will be changed. The tape then runs in the original direction of movement again, so that the device plays the same program, which was switched on before fast rewind.

In the above description, an electronic Control of the reversal of the transport speed of the tape is described, but this control can also be used by those skilled in the art Realize purely mechanically, whereby the changeover relay Rl is omitted.

Blank page

Claims (2)

PATENT CLAIMS 10 Method of initiating fast rewinding of a tape in a tape recorder and player by using the Tape is transportable in forward and reverse direction and which includes a fast forward mechanism, characterized by the following steps: - a first change in the transport direction of the belt is effected, - The tape is then fast forwarded causes and - A second change in the direction of transport of the tape is then triggered. 2. Device for effecting fast rewinding of a tape in a tape recording and reproducing device, in which the tape can be transported in the forward and reverse direction, and which has a fast forward mechanism 309881/0838 ORIGINAL INSPECTED SB7P-1976 nism, preferably according to claim 1, characterized in that - that a manual control (4) allows the setting of the fast forward, - That the hand control includes a short-time switch that During the switchover to and from the return position, an electrical contact closes briefly, via which the Reversal of the transport direction of the tape is controlled. 90 9 881/0838