GB2024492A

GB2024492A - Fast Rewind of Tape in Recording and/or Playback Apparatus

Info

Publication number: GB2024492A
Application number: GB7922066A
Authority: GB
Original assignee: Autovox SpA
Current assignee: Autovox SpA
Priority date: 1978-06-27
Filing date: 1979-06-25
Publication date: 1980-01-09
Also published as: FR2430058A1; IT7850035A0; BR7904004A; DE2925304A1; IT1105380B; ES481894A1; BE877257A; FR2430058B1; NL7904831A; JPS554798A

Abstract

When a manual actuator S4 moves between "normal" and "fast rewind" positions, in addition to lifting the pressure roller from the capstan, it briefly earths a monostable multivibrator 3 and hence causes a pulse to be delivered to relay R1 which reverses the direction of tape motion. When moving between "normal" and "fast forward" the line 2A is not earthed. Closing switch S3 also reverses the direction of tape movement. Automatic reversal of tape movement at each end of the tape is described also: a detector 1 senses the motion or otherwise of tape reel support 20 and hence causes a pulse to be delivered to the reversing relay R1 through logic break 2. <IMAGE>

Description

SPECIFICATION Improvements in or Relating to Processes and Devices for Effecting Fast Rewind Movements of the Tapes in Recording and/or Playback Apparatuses The present invention relates to a process and a device for effecting a fast rewind movement of a tape in a recording and/or playback apparatus which operates in both directions of movement of the tape.

It is known that, in a tape recorder, means must be provided for moving the tape fast in either direction in order to seek portions of the tape of particular interest.

In the recorders which operate in both directions of movement of the tape, i.e., of the "reverse" type, it is easy to provide mechanism for the fast forward movement of the tape: when the tape is advancing at normal speed in either of its two directions of advancement, it is sufficient to move the pressure roller away from the respective capstan to effect a fast forward movement of the tape.

In fact by moving the pressure roller away from the capstan, a friction device which entrains a hub-carrying disc no longer slips and therefore causes fast forward movement of the tape.

To effect fast rewind movement of the tape there is generally provided in the reverse-type recorders a mechanism for the fast rewind movement which is very complicated, which disengages the pressure roller from the respective capstan, disengages the wind-up reel from the tape transport mechanism and engages the unwind or delivery reel so that it becomes motive and rewinds the tape quickly.

Additionally, in the reverse-type recorders, the mechanical realization of the reversal of the direction of movement of the tape is generally realized by means of a relay.

According to one aspect of the invention, there is provided a process for effecting a fast rewind movement of a tape in a recording and/or playback apparatus which operates in both directions of movement of rhe tape and is equipped with the mechanism for fast forward movement of the tape, the process comprising the steps of: effecting a first change of the direction of movement of the tape; effecting a fast forward movement of the tape: and effecting a second change of the direction of movement of the tape.

According to another aspect of the invention, there is provided a device for effecting a fast rewind movement of a tape in a recording and/or playback apparatus capable of operating in both directions of movement of the tape, the device comprising: means for effecting a first change of the direction of movement of the tape; means for effecting a fast forward movement of the tape; and means for effecting a second change of the direction of movement of the tape.

It is thus possible to eliminate the mechanism of fast rewind movement of the tape, thus allowing a recorder to be simpler and more economic.

The invention will be further described, by way of example and not of limitation, with reference to the accompanying drawings, in which: Figure 1 is a block diagram of the circuit constituting a preferred embodiment of the invention; and Figure 2 is the detailed circuit diagram of the block diagram of Figure 1.

With reference to the drawings, and in particular to Figure 1, a preferred device comprises a detector 1 of the motion of a disc 20 supporting a wind-up reel of a tape. The detector 1 provides an output of a logic level 0 or 1 according to the state of rest or of motion of the disc 20. A first logic block 2 provides an output of a logic level 1 or 0 according to whether the disc 20 is stopped while before it rotated, or whether it is stopped while before it was stopped. A monostable multivibrator 3, responsive to the output of the first logic block 2, provides at its output, for each transition of the input from 1 to 0, a pulse which controls, by means of a buffer transistor 21, a relay R1 of reversal of the direction of movement of the tape. The relay R 1 reacts to each control pulse, causing the reversal of the direction of movement of the tape.

Two switches S 1 and S2 are interlocked to the position of a cassette of tape, the switch S2 closing as soon as there is initiated the operation of introduction of a cassette, exciting the relay R1, whereas the switch S1 closes when the cassette arrives at its operative position, feeding a motor 22.

A A lamp 23, connected to the output of the detector 1, signals the correct movement of the tape.

A manual control block 4 comprises a mechanical control for determining the fast forward movement of the tape by moving the pressure roller away from its respective capstan.

A temporary of "intermittent contact" switch S4 is interlocked to such mechanical control. Switch S4, in the movement of the manual control toward the fast rewinding position, ground temporarily a conductor 24. A switch S3 is then connected mechanically so as to be activated when the manual control is pushed.

The operation of the device is as follows: as soon as the introduction of the cassette begins, the switch S2 closes and the reversal relay R1 is excited. The output of the detector 1 is 0 while the output of the block 2 is 0, since the switch S 1 is open: the motor 22 does not rotate and the disc 20 is stopped and was stopped, for which reason the output of the monostable multivibrator 3 is 0.

There is thus confirmed the excitation of the relay R1.

As soon as the cassette arrives at its operative position, the switch S1 also closes and the motor 22 begins to rotate: the output of the detector 1 becomes 1 while the output of the block 2 remains 0, since now S2 is closed.

Downstream of the block 2 everything remains as before and the cassette is read on program I. At the end of program I, the tape arrives at the end of the run and the disc 20 stops: the output of the detector 1 becomes 0 and, since the switch S1 is closed and thus the voltage VB2#0, also the output of the block 2 becomes 1. This causes the triggering of the output pulse of the monostable multivibrator 3, which de-energizes the reversal relay R1 and thus causes the reversal of the direction of movement of the tape.

The motor-22 in the meantime continues to rotate and thus causes the program 11 to be read.

At the end of the program lithe disc 20 stops for the second time and the monostable multivibrator 3 again supplies a de-energizing pulse to the reversal relay R1.

This arrangement thus allows the continuous reproduction of the cassette, alternately on program I and on program II, ad infinitum.

When it is desired to change track or program, it is necessary to depress axially the manual control of the block 4: in this manner the user closes the switch S3 and the monostable multivibrator 3 supplies a de-energizing pulse to the relay R1, which causes the reversal of the direction of movement of the tape.

If it is desired to effect a fast forward movement, it is necessary to rotate the mechanical control of the block 4 in a counterclockwise direction, as viewed in the drawings: in this manner the pressure roller is moved away from the respective capstan and the tape can advance rapidly.

If it is wished to effect a fast rewind movement, it is necessary to rotate the mechanical control of the block 4 in a clockwise direction, as viewed in the drawings: in such a manner there is also mechanically effected a fast forward movement of the tape, but before and after the fast forward movement, a reversal in the direction of movement of the tape is effected since, in passing from the central position to the lateral position, the switch S4 grounds for an instant the conductor 24, in the same manner as the switch S4 grounds it while returning to its central position.

This sequence of operations thus permits the attainment of a fast rewind movement of the tape without the provision of any mechanical members for the fast rewinding.

The block circuit, shown schematically in Figure 1, has been realized in practice as shown in Figure 2.

in Figure 2 all the functional blocks shown in Figure 1 have been enclosed within dashed lines and have been indicated with the same reference numbers.

As shown in Figure 2, in the detector 1 of the motion of the disc 20, a sensor 25 of the capacitive type, such as that described in our copending application No. 79,07419, Serial No's.

is used as a sensor of movement of the disc 20. The circuit comprises an oscillator 26, having a frequency of oscillation of about 100 kHz, formed by three NOR gates of the CMOS type, a first detecting circuit 27 arranged to detect the modulation imparted by the capacitive sensor 25 and a second detecting circuit 28 arranged to provide an output of logic level 1 (output equal to the voltage VB2) if the modulation is present and of logic level 0 (ground output) in the absence of modulation.

The monostable multivibrator 3 comprises an integrated circuit 29 of the 555 type, capable of providing an output of a positive square pulse, the duration of which is determined by the capacitance of a capacitor 30 connected to the pin 6, if at the input there is present a negative pulse of any duration whatsoever. The input pulse is obtained by a differentiating circuit formed by a NAND gate 31 and by a resistor and capacitor network formed by a capacitor 32 and by a resistor 33. A positive voltage step is supplied to the input of the NAND gate 31.

The conductor 24, from the block 4 of the manual control, is connected to the output of the NAND gate 31, so that each time one of the switches of the block 4 is closed, a negative pulse is supplied to the input of the integrated circuit 29. In this manner, for each closing of one of the switches of the block 4, the monostable multivibrator 3 delivers a control pulse for the relay R1.

In operation, at the moment of introduction of the cassette, the switch S2 closes. In this condition the output of the detector 1 is still 0, the output of the block 2 is 0, the input of the integrated circuit 29 (pin 2) is 1 and thus the reversal relay R1 becomes excited.

The motor 22 is stopped since the switch S1 is open and thus the voltage VB2 is not present.

When the cassette arrives to its operative position, the switch S1 closes: the output of the detector 1 goes to 1 , the output of the block 2 remains at 0, so that ail the circuit downstream of the block 2 remains as before, except for the motor 22 which in put in motion since now there is present the voltage VB2.

Thus the program I is read. At the end of the tape, the output of the detector 1 goes to 0, bringing to 1 the output of the block 2. The trnnsiric,n from U to 1 of the output of the block 2 causes, as has already been indicated, the triggering of the de-energizing pulse of'the reversal relay R1, while the motor 22 continues to rotate.

The de-energizing of the reversal relay R1 causes the mechanical predisposition for movement in the opposite direction. When this predisposition takes place, the disc 20 begins to rotate again, the output of the detector 1 returns to 1 and the output of the block 2 returns to 0, while the motor 22 continues to remain excited.

Thus the program II is read.

At the end of the tape, the output of the detector 1 returns to 0, bringing to 1 the output of the block 2: there is thus produced a control pulse for the monostable multivibrator 3, with the resulting de-energizing of the reversal relay R1.

When the cassette is moved away from its operative position, the opening of the switch S1 causes the transition to 0 of the output of the block 2, and the de-energizing of the motor 22, since the switch S1 is open and consequently the voltage VB2 is zero.

When the cassette is removed from the opening of the apparatus, then the switch S2 opens and everything returns to rest.

The closing of the switch S3 causes a deenergizing control for the reversal relay R 1 and thus permits a manual reversal of the direction of movement of the tape to be effected.

As has already been stated, in order to effect a fast rewind movement of the tape, it is necessary to rotate the handle of the manual control block 4 and thus the switch S4 connected to it, in a clockwise direction as viewed in the drawings. In this manner there are effected the following operations in succession: first there is temporarily grounded the output of the NAND gate 31 and the apparatus effects a reversal of the direction of movement; secondly there is effected mechanically a fast forward movement of the tape, moving the pressure roller away from the respective capstan. It is to be noted that a fast forward movement in the opposite direction to that of listening corresponds in reality to a fast rewind movement of the tape, which is what is required.

When the switch S4 is made to return to its central position, it again grounds the conductor 24 and thus causes a second change of the direction of movement of the tape, restoring the original direction of movement of the tape and causing the recorder to play-back the same program which was being listened to before effecting the fast rewind movement of the tape.

While there has been described a realization having an electronic control of reversal of the movement of the tape, it is simple for one skilled in the art to arrive at a variation in which the control is of a strictly mechanical type, in which case the relay R1 is no longer necessary

Claims

1. A process for effecting a fast rewind movement of a tape in a recording and/or playback apparatus which operates in both directions of movement of the tape and is equipped with a mechanism for fast forward movement of the tape, the process comprising the steps of: effecting a first change of the direction of movement of the tape; effecting a fast forward movement of the tape: and effecting a second change of the direction of movement of the tape.

2. A device for effecting a fast rewind movement of a tape in a recording and/or playback apparatus capable of operating in both directions of movement of the tape, the device comprising: means for effecting a first change of the direction of movement of the tape; means for effecting a fast forward movement of the tape; and means for effecting a second change of the direction of movement of the tape.

3. A device as claimed in claim 2, in which a manual control is provided for effecting a fast forward movement of the tape, the manual control being connected to an intermittent switch which, during passage to and from a rewinding position, closes an electrical contact which is arranged to control a reversal of the direction of movement of the tape.

4. A process for effecting a fast rewind movement of a tape in a recording and/or playback apparatus which operates in both directions of movement of the tape, substantially as hereinbefore described.

5. A device for effecting a fast forward movement of a tape in a recording and/or playback apparatus capable of operating in both directions of movement of the tape, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

6. A recording and/or playback apparatus capable of operating in both directions of movement of a tape and including a device as claimed in any one of claims 2, 3, and 5.