JPH0430664Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is equipped with two cassette tape drive units, and is capable of simultaneously reproducing all tracks of one cassette tape and simultaneously recording all tracks of the other cassette tape. The present invention relates to a cassette tape recorder capable of recording data, and more particularly to a cassette tape recorder that completely prevents erroneous erasure of a cassette tape on the recording side.

[Prior art]

Conventionally, when duplicating the contents of a cassette tape, for example, two cassette tape recorders were connected, one of the cassette tape recorders played back, and the other recorded.

In addition, some cassette tape recorders are equipped with two cassette tape drive sections so that the contents of the cassette tape can be easily duplicated. This type of cassette tape recorder is generally constructed such that one cassette tape drive section is dedicated to playback, and the other is a recording/playback section.

By the way, cassette tapes generally have a forward and return track. Cassette tape recorders usually have a head for only one track. Now, if the head is in the lower half of the full width of the cassette tape, and the track at this head position is the forward track (this is called side A), and the other track is the return track (this is called side B), then When using side B, the tape cassette must be turned over.

Since the above-mentioned cassette tape recorder with two cassette tape drives also has only a head for side A, it is necessary to turn both tape cassettes over when duplicating the contents of the cassette tapes.

Therefore, in order to eliminate the need for this flipping operation and to shorten the time required to copy the contents of a cassette tape, both cassette tape drive units are equipped with heads for side A and side B of the cassette tape, and a head for side A and side B of the cassette tape is provided for playback. There is a cassette tape recorder that is capable of simultaneously reproducing sides A and B of a cassette tape in a dedicated section and simultaneously recording on sides A and B of the cassette tape in a recording/playback section. Some cassette tape recorders of this type double the tape running speed to significantly reduce the time required for duplication.

Incidentally, a tab is provided on the back of the tape cassette to prevent erroneous erasing, and when this tab is broken off and removed, erasing and re-recording become impossible, thereby preventing erasure due to erroneous operation.
There are two claws, one for side A and one for side B. Since a general cassette tape recorder records or plays only one side of the cassette tape, the presence or absence of this pawl is detected only in one place. In the case of manual operation buttons, the erase and record circuits do not operate even if the record button is pressed.

The above-mentioned cassette tape recorder, which is capable of simultaneously recording sides A and B of a cassette tape using mechanical operation buttons, also detects the presence or absence of a chisel for side A.

[Problem to be solved by the invention] In the above-mentioned cassette tape recorder, which is capable of simultaneous recording of sides A and B using mechanical operation buttons, if the tab for side A is broken when simultaneously recording, the record button cannot be pressed. can no longer be pressed, preventing accidental erasure. However, when the tab for side A is not broken, the record button can be pressed even if the tab for side B is broken, so a problem arises in that both sides A and B are erased.

The object of the present invention is to solve these problems and provide a cassette tape recorder that completely prevents erroneous erasure during simultaneous recording of sides A and B.

[Means for solving problems]

The present invention has two cassette tape drive sections, and has the function of simultaneously reproducing all tracks of one cassette tape and simultaneously recording on all tracks of the other cassette tape. In a cassette tape recorder that is equipped with a function that mechanically detects the presence or absence of one of the two accidental erasure prevention pawls on the tape cassette installed in the tape cassette and performs an accidental erasure prevention operation, the other accidental erasure prevention pawl of the tape cassette is A switch mechanism that detects the presence or absence of a track, a changeover switch for switching between recording and playback, a track selection switch that selects between all-track recording and single-sided track recording, and a bias signal oscillation circuit that supplies a bias signal to the recording system. A first control circuit performs control to stop the drive motor for running the cassette tape, and a second control circuit performs control to prohibit the operation of the first control circuit.

[Effect]

In the cassette tape recorder according to the present invention,
The above selector switch is set to the recording state, and
When the track selection switch is set to the all-track recording state, the first control circuit is operated, the track selection switch is set to the all-track recording state, and the switch mechanism causes the tape cassette to be recorded. When it is detected that the other accidental erasure prevention claw is not broken, the second control circuit prohibits the operation of the first control circuit and operates the bias signal oscillation circuit and the drive motor. .

〔Example〕

Embodiments of the cassette tape recorder according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a radio-integrated cassette tape recorder in which a tuner section of a radio receiver is integrated into a cassette tape recorder according to the present invention.
1 is a block diagram of an embodiment of a so-called radio cassette; FIG.

This radio cassette mainly consists of tuner section 1,
Playback only section 10, recording/playback section 30, audio section 9
0, an erroneous erasure prevention circuit 70. In the block diagram of FIG. 1, the mechanical parts of this radio cassette are omitted. In addition, the above recording replay part 3
0, only the recording system is shown, and the reproducing system is omitted.

Figure 2 shows the recording/playback section 30 of the radio cassette.
1 is a configuration diagram of heads used in The recording/reproducing head 105 has recording/reproducing head elements 33, 34 for the A side and B
It is equipped with recording/reproducing head elements 37 and 38 for sides, and can simultaneously record in stereo on sides A and B. In addition, the shape of the erase head element 46 of the erase head 106 is determined so that only side A is erased, and the shape of the erase head element 47 of the erase head 107 is determined so that side A and B can be erased simultaneously. ing. The reproducing head of the reproducing-only section 10 has the same shape as the recording/reproducing head 105 and includes four reproducing head elements, and is not shown in the drawing.

FIG. 3 is a schematic diagram showing the direction of movement of the cassette tape used in the radio cassette during recording or reproduction. The arrow indicates the direction of movement as seen from the magnetic surface of the cassette tape.

As shown in FIG. 3a, the cassette tape 19 used in the reproduction-only section 10 of the radio cassette has side A 100 on the bottom half and recording to the right, and side B 101 on the top half. Assume that it is recorded to the left. As shown in FIG. 3B, side A 100 and side B 101 are simultaneously reproduced in the right direction by reproduction head 104. At this time A
Surface 100 is reproduced in the same direction as the recording direction, but B
Surface 101 will be reproduced in the opposite direction to the recording direction. The playback signal of the side A 100 and the playback signal of the side B 101 that are played back at the same time are transferred to the side A 102 of the cassette tape 48 of the upper recording/reproducing section 30, as shown in FIG. 3c.
and are simultaneously recorded on the B side 103 in the right direction.

When playing back this cassette tape 48,
Lower recording/reproducing head element 3 of upper recording/reproducing head 105
Only 3 and 34 are used. Since the signal reproduced in the same direction as the recording direction is recorded on side A 102, it is sufficient to reproduce the signal in the recording direction, that is, in the right direction, as shown in FIG. 3d. Since the signal reproduced in the opposite direction to the recording direction was recorded on the B side 103 in the same direction as the A side 102, it is necessary to reproduce the signal in the opposite direction to the A side 102. When the tape cassette is turned over, the tape is played back in the direction opposite to the side A 102, so that the playback is the same as that of a normal cassette tape, as shown in FIG. 3d. Therefore, a cassette tape reproduced using the radio cassette described above can also be played on a general tape recorder.

Next, the block diagram shown in FIG. 1 will be explained in more detail.

The tuner unit 1 receives broadcast radio waves through an antenna 2, demodulates them in the case of FM stereo broadcasting, and sends the audio signal of the left channel (hereinafter referred to as LCH) to the terminal 3, and sends the audio signal of the right channel (hereinafter referred to as RCH). .) is output to terminal 4. Terminal 3 is connected to terminal 5b of switch 5 and switch 7.
is connected to terminal 7b of. Further, the terminal 4 is connected to a terminal 6b of the switch 6 and a terminal 8b of the switch 8. The switches 5 and 6 are of the interlocking type, and the switches 7 and 8 are also of the interlocking type.

The reproduction-only section 10 includes a reproduction head element 11 and a reproduction circuit 12 for the LCH of side A of the cassette tape, and a reproduction head element 13 and a reproduction circuit 14 for the RCH so as to enable stereo reproduction. Also, in order to enable stereo reproduction of side B of the cassette tape in the same way as side A, a playback head element 15 and a playback circuit 16 for KCH and a playback head element 17 and playback circuit 18 for RCH are provided. The recorded cassette tape 19 can also play only the A side.
Simultaneous reproduction of both sides of AB is also possible, but FIG. 1 shows the state when both sides of AB are played simultaneously. The output of the reproducing circuit 12 for the LCH on side A is connected to the terminal 7c of the switch 7, and the output of the reproducing circuit 14 for the RCH is connected to the terminal 8c of the switch 8. The terminal 7a of the switch 7 is connected to the terminal 5c of the switch 5 and the upper recording/reproducing section 3.
The terminal 8a of the switch 8 is led to the terminal 6c of the switch 6 and the recording circuit 32 of the upper recording/reproducing section 30. The switches 7 and 8 switch between the signal from the reproduction only section 10 and the signal from the tuner section 1 and supply the signal to the upper recording and reproducing section 30 and the switches 5 and 6. Further, the switches 5 and 6 switch between the signal from the tuner section 1 and the signal passed through the switches 7 and 8, and supply the signal to the audio section 90.

The above audio section 90 is an amplifier circuit 9 for LCH.
1 and an amplifier circuit 92 for RCH, which amplifies the signal inputted through the switches 5 and 6 and outputs the signal to LCH.
Drives the speaker 93 and RCH speaker 94.

By switching the switches 5 and 6 to the tuner section 1 side, by switching the switches 7 and 8, it is possible to record the radio broadcast on the cassette tape 48 of the upper recording and reproducing section 30 while listening to the radio broadcast. It is also possible to record the contents of the cassette tape 19 of the read-only section 10 onto the cassette tape 48 of the recording/reproducing section 30.

The upper recording/reproducing section 30 includes an LCH recording/reproducing head element 33 for the A side, an RCH recording/reproducing head element 34, an erasing head element 46, an LCH recording/reproducing head element 37 for the B side,
RCH recording/reproducing head element 38, erasing head element 47
It is equipped with The output of the recording circuit 31, to which the signal passed through the switch 7 is input, is supplied to the upper recording/reproducing head element 33, and the output of the recording circuit 32, to which the signal passing through the switch 8 is input, is supplied to the upper recording/reproducing head element 34. is supplied to Also, the recording circuit 35
The output of the reproducing circuit 16 of the reproduction-only section 10 is led to the recording circuit 36, and the output of the reproducing circuit 18 is led to the recording circuit 36. The output of the recording circuit 35 is supplied to the upper recording/reproducing head element 37, and the output of the recording circuit 36 is supplied to the upper recording/reproducing head element 38.

In addition, the upper recording/reproducing head elements 33, 34, 37, 3
8 and erase head elements 46 and 47 are supplied with a bias signal by a bias signal oscillation circuit 60. The bias signal oscillation circuit 60 is composed of a transistor 39, a transformer 40, resistors 41, 42, capacitors 43, 44, 45, etc. The collector of the transistor 39 is connected to the transformer 40.
The emitter is connected to the primary side terminal 40a of the resistor 41, and its emitter is grounded through a resistor 41. The base of the transistor 39 and the primary terminal 4 of the transformer 40
A resistor 42 and a capacitor 44 are connected in parallel between 0b, and a capacitor 43 whose one end is grounded is connected to the base. A DC voltage is supplied to a terminal 40c at the center of the primary side of the transformer 40. Further, a capacitor 45 whose one end is grounded is connected to the terminal 40c.

The bias signal is supplied from a terminal 40g on the secondary side of the transformer 40 via a capacitor 49 to the upper recording/reproducing head element 33, and via a capacitor 50 to the upper recording/reproducing head element 34. Also, from the terminal 40f to the erase head element 47 via the switch 52,
After passing through the switch 52, the signal is supplied to the upper recording/reproducing head element 37 via the capacitor 53, and to the upper recording/reproducing head element 38 via the capacitor 54. The signal is also supplied to the erase head element 46 from the terminal 40e via the switch 53. The above switches 52, 53
are of an interlocking type and switch between the bias signal and the ground level, so that when one is switched to the ground side, the other is switched to the bias signal side.

Further, the erase head element 46 erases only the A side, and the erase head element 47 is formed so that it can erase the A side and the B side at the same time.
In the case of surface simultaneous recording, a bias signal is supplied to this erasing head element 47 by switches 52 and 53,
No bias signal is supplied to the erase head element 46. The erase head element 4
6 and the erase head element 47 have different shapes and therefore different impedances. In addition, the above transformer 40
Although the oscillation frequency of the bias signal oscillation circuit 60 changes due to a change in the load on the secondary side of the eraser, the capacitor 55, 56 can be adjusted.

Further, depending on the reception frequency, noise may be generated due to harmonics of the oscillation frequency. At this time, the capacitor 57 is
Alternatively, the capacitor 58 can be connected to the second transformer 40.
By adding it to the next side and slightly shifting the oscillation frequency, noise can be removed.

The bias signal oscillation circuit 60 is controlled by an erroneous erasure prevention circuit 70. Next, this erroneous erasure prevention circuit 70 will be explained.

The above-mentioned erroneous erasure prevention circuit 70 includes a transistor 7
1, 72, 73, 74 and resistors 75, 76, 77,
The control circuit 80 includes switches 81, 82, 83, and 84.

The switch 81 is turned on when the contents of sides A and B of the cassette tape 19 in the read-only section 10 are simultaneously recorded on the cassette tape 48 of the upper recording/reproducing section 30.
becomes.

As shown in FIG. 4, the switch 82 constitutes a switch mechanism 110 for detecting the presence or absence of the erroneous erasure prevention tab on the B side of the cassette of the upper recording/reproducing section 30. This switch 82 is for example used when the cassette 1 is
When the claw 112 on the back of 11 is not broken, the contact is controlled by the lever 113 and turns ON.
When the pawl 112 is broken, it is turned OFF.

Switch 83 is ON during recording and during playback.
It becomes OFF. The switch 84 is turned ON when A and B sides are simultaneously recorded, and turned OFF when recording on one side.

A resistor 75 is connected to the base of the transistor 71, and a base current can be supplied through the resistor 75 and switches 81 and 82. The emitter of the transistor 71 is grounded, and the collector is connected to resistors 76, 77, and 78. The other end of the resistor 76 is connected to a switch 84. The other end of the resistor 77 is connected to the base of a transistor 72 whose emitter is grounded, and the collector of this transistor 72 is connected to the base of the transistor 39 of the bias signal oscillation circuit 60. The other end of the resistor 78 is connected to the base of a transistor 73 whose emitter is grounded, and the collector of this transistor 73 is connected to the base of a transistor 74. A resistor 7 is connected between the collector and base of this transistor 74.
9 is connected, a DC voltage is supplied to the collector, and the emitter is led to a drive motor 59.

The operation of this erroneous erasure prevention circuit 70 will be explained below.

First, when only one side of the cassette tape is used, since the switch 84 is turned off, bias current cannot be supplied to the transistors 72 and 73, and therefore the transistors 72 and 73 do not operate. Therefore, the base of the transistor 39 of the bias signal oscillation circuit 60, which is connected to the collector of the transistor 72, is not affected and the oscillation is stable. Furthermore, since the transistor 73 does not operate, the transistor 74 connected to the collector of the transistor 73 is not affected and supplies a constant current to the drive motor 59.
supply to

Next, when simultaneously recording the A and B sides, the switch 84 is set to ON, and the switch 83 is set to ON. Also, switch 81 is set to ON and side A and B
Simultaneous recording is possible. At this time, the upper recording and reproducing section 3
When the accidental erasure prevention tab for side B of tape cassette No. 0 is not broken, the switch 82 is turned on, and sufficient base current is supplied to the transistor 71 via the switches 81, 82 and the resistor 75. Therefore, this transistor 71 reaches a saturation region, and the collector potential becomes approximately equal to the ground level. Therefore, no base current is supplied to the transistors 72 and 73, and the transistor 7
2 and 73 do not operate, the bias signal oscillation circuit 60 operates stably, and a constant current is also supplied to the drive motor 59. Therefore, simultaneous recording on both sides of the cassette tape, A and B, is possible.

However, when the accidental erasure prevention tab on the B side is broken, the switch 82 is turned OFF, so the base current cannot be supplied to the transistor 71.
This transistor 71 does not operate. At this time, a sufficient base current is supplied to the transistor 72 by the resistors 76 and 77, and the transistor 72 reaches saturation and the collector potential becomes approximately equal to the ground level. The above bias signal oscillation circuit 6
Since the base of the transistor 39 of 0 is connected to the collector of the transistor 72, it has a potential substantially equal to the ground level, and this transistor 39 becomes inoperable, so that oscillation is stopped.

The transistor 73 also includes the resistor 7.
6, 78 causes a sufficient base current to flow, reaching saturation, and the potential of the collector becomes approximately equal to the ground level. Therefore, the transistor 74 becomes inoperable, and the current supply to the drive motor 59 is stopped.

The reason why the operation of the bias signal oscillation circuit 60 and the drive motor 59 are stopped at the same time is that when the record button is pressed, the heads move and come into contact with the cassette tape 48, and at this time, if the This is to avoid the fact that if only the drive motor 59 is stopped, the areas in contact with the heads will be erased. Furthermore, if only the operation of the bias signal oscillation circuit 60 were to be stopped, there is a possibility that noise from the circuit system would be recorded as the cassette tape 48 runs, and this is to be avoided.

In the radio cassette of this embodiment, when the erroneous erasure prevention claw for side A of the cassette tape is broken, the record button of the mechanical operation button cannot be pressed, thereby preventing erroneous erasure. If the accidental erasure prevention tab for side A is not broken and the accidental erasure prevention tab for side B is broken, you can press the record button, but as described above, the drive motor 59 will stop and at the same time the bias Since the signal supply is also stopped, erroneous erasure can be completely prevented.

[Effect of idea]

As described above, in the cassette tape recorder according to the present invention, when all tracks of one cassette tape are simultaneously played back and all tracks of the other cassette tape are simultaneously recorded, both tape cassettes on the recording side are When the accidental erasure prevention claw is not broken, the second control circuit prohibits the operation of the first control circuit, and the bias signal oscillation circuit and the drive motor are operated;
All tracks can be recorded. Furthermore, when one of the recording-side tape cassette's accidental erasure prevention tabs is not broken and the other accidental erasure prevention tab is broken, the first control circuit is activated even though the recording button cannot be pressed. Since the operations of the bias signal oscillation circuit and the drive motor are stopped, erroneous erasing can be reliably prevented.
Moreover, in the cassette tape recorder according to the present invention, as described above, erroneous erasure is prevented by controlling the operation of the bias signal oscillation circuit to be stopped, so that the response of the control for preventing erroneous erasure is fast.
Moreover, the power required for control is small, and the power consumption is also reduced by stopping the operation of the bias signal oscillation circuit, so it is possible to realize an erroneous erase prevention function with extremely low power consumption.
Therefore, as shown in the embodiments, it is possible to provide a radio cassette etc. that is free from the risk of erroneous erasure.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of a so-called radio cassette in which a tuner section is integrated into a tape recorder according to the present invention. FIG. 2 is a block diagram of the heads used in the recording/reproducing section of the above embodiment. FIG. 3 is a schematic diagram showing the recording or reproducing direction of the cassette tape used in the above embodiment. FIG. 4 is a schematic diagram of the switch mechanism used in the recording/reproducing section of the above embodiment. 10...Reproduction only section, 19, 48...Cassette tape, 11, 13, 15, 17...Reproduction head element, 30...Recording/reproduction section, 33, 34, 37, 38
...Recording/reproducing head element, 46, 47... Erasing head element, 59... Drive motor, 60... Bias signal oscillation circuit, 70... Erroneous erasure prevention circuit, 80...
...Control circuit, 81, 82, 83, 84...Switch, 110...Switch mechanism, 112...Claw.

Claims (1)

[Claims for Utility Model Registration] It has two cassette tape drive units, and has the function of simultaneously reproducing all tracks of one cassette tape and recording simultaneously to all tracks of the other cassette tape. In a cassette tape recorder equipped with a function of mechanically detecting the presence or absence of one of the two accidental erasure prevention pawls of the tape cassette installed in the cassette tape drive unit and performing an accidental erasure prevention operation, the other of the tape cassettes mentioned above is A switch mechanism that detects the presence or absence of a tab to prevent accidental erasure, a changeover switch for switching between recording and playback, a track selection switch that selects between all-track recording or single-sided track recording, and a bias signal for the recording system. A first control circuit that performs control to stop the bias signal oscillation circuit to be supplied and a drive motor for running the cassette tape, and a second control circuit that performs control to prohibit the operation of the first control circuit, When the changeover switch is set to the recording state and the track selection switch is set to the all-track recording state, the first control circuit is operated, and the track selection switch is set to the all-track recording state. is set, and when the switch mechanism detects that the other accidental erasure prevention claw of the tape cassette is not broken, the second control circuit prohibits the operation of the first control circuit; A cassette tape recorder characterized in that the bias signal oscillation circuit and the drive motor are operated.