GB2047940A - Autoreverse Tape Cassette Deck - Google Patents

Abstract

The deck includes an arrangement for playing the preferential track when a cassette is inserted. In normal operation, a motion detector 5,1 switches to a high output when the take-up spool 5 stops and multivibrator 2 then produces an output to actuate relay R via transistor 6 and cause the tape to reverse. Switches S2 and S3 are controlled by a bistable member such that S2 is closed and S3 open when the tape is moving in the preferential direction and S3 is closed and S2 open in the other direction. When start switch S1 is closed the output of bistable 3 is reset to 0 via capacitor C. If S3 is then closed (non-preferential direction), OR gate 4 gives a 0 output to reverse the tape. S2 then closes to set bistable 3 and hold the OR gate output high. Thereafter capacitor 8 charges and bistable 3 cannot be reset until the cassette is ejected. <IMAGE>

Description

SPECIFICATION Device for Playing the Preferential Track in an Autoreverse Tape Cassette Deck This invention refers to a device for playing the preferential track in an autoreverse tape cassette deck, upon insertion of the cassette.

When a tape cassette is inserted and played on a usual cassette deck of a non reverse type, the tape in the cassette is always moved from left to right and therefore the here so-called "preferential" track or track A, or track 1 is played, the other track, or track B or track 2 being cited as the non preferential track.

Conversely, in autoreverse cassette tape decks, when the cassette is ejected at the end of played track, the control for reversal of the tape direction of movement either remains preset in the same playing direction or presets for the next reversal step. Furthermore, when the cassette is ejected while playing, this preset control remains generally unchanged.

As a consequence, in those cases in which the reversal control remains preset, the track which plays when a cassette is now inserted is the same as when the tape deck had been used last. On the other hand, when the reversal control presets for the next reversal step, the track which plays is the opposite one.

In any case, the first actual playing direction is not known in advance, and this is a very annoying inconvenience for the user, because, in practice, every time he inserts a cassette, he does not known which track will be played first.

The main object of the device according to this invention is therefore to overcome the disadvantages described above, causing the track first played after the insertion of the cassette to be the so-called preferential one, which corresponds to playing track A, or track 1 of a cassette inserted with its side A, or side 1, upwards, no matter what playing direction the tape tranport mechanism had been on the last time the tape deck had been used.

According to the present invention, a device for playing the preferential track in a tape cassette deck comprises: detecting means for detecting the direction in which the tape moves upon insertion of a cassette, said detecting means having a first output when the direction of movement of the tape is such that the preferential track of the tape is read, and a second output when the direction of movement of the tape is such that the non preferential track of the tape is read; and reversing means, responsive to said second output, for positively carrying out a reversing operation when the non preferential track is read.

Means are further provided for eventually disabling the device after said reversing operation.

An embodiment of the device according to the invention will now be described by way of example, which is not to be intended in any limiting sense, with reference to the accompanying drawings, in which: Figure 1 is a block diagram of the device; and Figure 2 is a circuit diagram of the device.

With reference to Figure 1, the device comprises a detector 1 of the motion of disc 5 carrying the hub for the take-up or tape receiving reel. Detector 1 yields as output a logic level 0 or 1, according to the state of motion or of rest, respectively, of hub carrying disc 5.

A monostable multivibrator 2, responsive to the output of detector 1, at every change of its input from 0 to 1 , yields as output a negativegoing pulse, which controls a reversing relay R1, which reverses the tape direction when deenergized through a transistor 6.

The device further comprises a switch S1, interlocked to the cassette position, whch switch S1 closes when the cassette is in its operative position, thus energizing relay R1 and motor 7 and the other components.

Two switches S2 and S3 close, respectively, according to the position of a bistable member which presets the tape direction of movement for playing track 1 or the tape direction of movement for playing track 2.

Furthermore, the device comprises a bistable multivibrator 3, which, through a capacitor 8, resets to 0 upon turning on the apparatus, and changes or sets to 1 only when S2 is closed to ground (direction for playing track 1). An OR gate 4 has a 0 level as output only if, after S1 is closed, S3 closes first (direction for playing track 2), and such 0 output of OR gate 4 causes deenergization of relay R1, through transistor 6, and, therefore, reversing of the tape movement direction.

The block diagram, shown schematically in Figure 1, has been actually put into practice as shown in Figure 2.

In Figure 2, all functional blocks shown in Figure 1 have been enclosed in broken lines and are identified with same reference numbers.

In operation, always referring to the drawings, when, after insertion, the cassette goes into the operative position, S1 closes thus supplying power to relay R1 and motor 7.

Motor 7 begins to turn, thus transmitting movement to hub carrying disc 5. Output of block 1 is therefore 0 and output of block 2 is 1, which confirms energization of relay R1 ,through transistor 6.

At this point two situations may occur: A) S3 is closed and therefore S2 is open.

B) S3 is open and therefore S2 is closed.

In situation A) direction for playing track 2 is either preset or about to be preset; conversely, in situation B), direction for playing track 1 is either preset or is about to be preset.

In situation A) the output of block 4 is 0 since both its inputs are 0 (if S2 is open, block 3 is reset to 0 upon closure of S1 through capacitor 8). But if the output of block 4 is 0, relay R1 deenergizes, thus reversing the direction of movement of the tape; at this point we are in situation B); therefore, the output of block 3 becomes 1 and the output of block 4 becomes 1, and relay R1 is energized again, thus causing the tape to move in direction for playing track 1 , which is the desired direction.

Thus, the result is achieved of always having the direction for playing track 1 as first direction of movement of the tape when a cassette is inserted and played, even if direction for playing track 2 would have been preset when the tape deck had been used last.

Since block 3 has changed its state to have as output a logic level 1 any successive change in state of S2 and S3 will bring no change to the output of block 4, which is at logic level 1 and will always stay 1.

In situation B) instead, output of block 4 is 1, because one of its inputs is at a logic level 1, S3 being open; under these circumstances no deenergization of relay R1, and therefore no reversing of direction of movement takes place.

It should be noted that, due to its irresponsiveness to the change of state of S1 and S2 in situation B, as previously stated, the device becomes automatically disabled when it reaches situation B.

The direction preset or in the process of being preset is and will be the direction for playing track 1.

It should be further clarified that, in the case in which, after insertion of the cassette, S2 and S3 both remain open for a first time interval, no operating alteration is brought about since in this phase the output of block 3 is 0 and the other input of block 4 is 1, so the output of block 4 is 1, which does not cause deenergization of relay R1.

It is obvious that a plurality of different variations may be brought to the invention described heretofore by those skilled in the art, without departing from the field thereof; it is intended that all such variations fall within the scope of the invention.

Claims (5)

Claims

1. A device for playing the preferential track in an autoreverse tape cassette deck, comprising: detecting means for detecting the direction in which the tape moves, upon insertion of a cassette, said detecting means having a first output when the direction of movement of the tape is such that the preferential track is read, and a second output, when the direction of movement of the tape is such that the non preferential track of the tape is read; and reversing means, respsonsive to said second output, for positively carrying out a reversing operation when the non preferential track is read.

2. The device according to claim 1, in which said detecting means comprises: two switches, one open and the other closed, alternatively, according to the position of a bistable member which presets the tape direction of movement, a first switch being closed when the preferential track plays and the second switch being closed when the non preferential track plays.

3. The device according to claim 1 or 2, further comprising disabling means for eventually disabling the device after said reversing operation.

4. The device according to claims 2 and 3, in which said reversing means and said disabling means comprise: an OR gate having a first input connected to said second switch; a bistable multivibrator, having its output connected to a second input of said OR gate and its set input connected to said first switch; and a capacitor connected to the reset input of said bistable multivibrator, for resetting the bistable multivibrator when a cassette is initially inserted and played, the arrangement being such that the output of said OR gate, when at a logic 0 level, causes a reversing relay to be deenergized to carry out said reversing operation.

5. A device for playing the preferential track in an autoreverse tape cassette deck, substantially as hereinbefore described with reference to the accompanying drawings.