JPH0430668Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a playback surface setting circuit that always plays from a predetermined surface when a cassette pack is inserted in an auto-reverse type cassette deck.

[Conventional technology]

Auto-reverse type cassette decks display the current direction of travel using an indicator, etc., but if the user does not remember which side of the cassette pack is facing up, even if only the direction of travel is displayed, It is not possible to determine which side is being played. Generally, the front and back sides of the cassette pack are A,
This is called the B side, and in non-reverse type cassette decks, only R (rightward) travel is possible, so the side facing up is always played. On the other hand, with an auto-reverse type cassette deck, playback can be performed not only when running in the R direction but also when running in the L (left direction) direction, so which side is being played can be determined by combining the upper side and the tape running direction at that time. There is a need.

[Problem that the invention attempts to solve]

However, even if various indicators are provided for in-vehicle use, if the driver visually recognizes them, it is dangerous to drive. In order to improve this point, the present invention is designed to ensure that the playback surface is always constant when a pack is inserted in an auto-reverse type cassette deck.

[Means for solving problems]

Fig. 1 is a basic block diagram of the present invention, in which 1 detects sides A and B of a cassette pack and generates a detection signal A/
A side and B side detection circuit that outputs B, 2 detects the insertion of a cassette pack and outputs a detection signal for a certain period of time.
A pack insertion detection circuit outputs DET, and 3 is an initial setting circuit that receives outputs A/B and DET from both detection circuits and instructs the tape running direction so that a preset side is played for a certain period of time when a pack is inserted. ,
4 is a running direction indicating circuit which receives the output R'/L' and indicates the actual tape running direction R/L. 8
is a drive circuit that receives the output of the instruction circuit 4 and controls the switching direction of the tape running direction.

[Operation] The detection circuit 1 includes a switch (S ₁ to be described later) that detects the presence or absence of a screw hole 51 provided on the A side of the cassette pack 5 shown in FIG. 2, for example.
On the other hand, the detection circuit 2 includes an insertion detection switch _S2 which is pressed on the side or end of the pack 5, as shown in FIG. 2, for example. The initial setting circuit 3 operates for a certain period of time upon receiving the detection signal DET, and produces outputs R'/L' according to the detection signals A/B. for example,
If it is set to always play from side A when a pack is inserted, if detection signal A (side A is on top) is generated, a right drive signal R' will be output. Conversely, when detection signal B (side B is on top) is generated, side B will be regenerated when the right running signal R' is output, so in this case, the left running signal will be
Give L′. In this way, even if the cassette pack 5 is inserted with either side A or B facing up, it will always be played from side A. Of course, it can also be configured to play back from side B. Running direction indication circuit 4
uses a microcomputer to determine the output R/L. However, the actual running direction R/L is determined according to the output R'/L' of the initial setting circuit 3 only when the pack is inserted, and when a switch input such as fast forward, rewind, direction reversal, etc. is received, Determine the output R/L according to the instructions.

Note that by using the output A/B of the detection circuit 1 and the output R/L of the instruction circuit 4, the actual reproduction surface can be displayed.
Reference numeral 6 in FIG. 1 is a control circuit therefor, and reference numeral 7 is a display circuit. Examples will be described below.

〔Example〕

Figure 3 shows an embodiment of the present invention, in which the A side and B side detection circuit 1 is turned on when the cassette pack 5 is inserted with the A side facing up, and is turned off when the B side is the front side. ₁ and a transistor _Q1 that inverts its output A/B. The initial setting circuit 3 inverts the output A/B of the switch _S1 with a transistor _Q6 and makes it the first input of the AND gate _A2 .
The inverted output of transistor _Q6 is further connected to the transistor
It is inverted at _Q7 and used as the first input of AND gate _A1 .
The outputs R′ and L′ of these AND gates A ₁ and A ₂ are on the right,
This is the left traveling direction signal, but this is limited to a certain period of time immediately after the pack insertion when the detection signal DET of the pack insertion detection circuit 2 becomes "1". This detection circuit 2
is a switch that turns on when the pack is inserted and turns off when it is ejected.
_S2 , a differentiating circuit _C1R1 that differentiates its output to detect pack insertion, and a monostable multivibrator MM activated by the differential pulse _, and this "1" output becomes the detection signal DET.

Explain the operation. When the cassette pack is inserted with the A side facing up, the switch _S1 is turned on, so the signal A/B is " ₁ ", and therefore the first
The input becomes "1" and the first input of AND gate _A2 becomes "0". Here, when the detection signal DET becomes “1”, the output R′ of AND gate _A1 becomes “1”
Then, the right drive instruction is given. As a result, the running direction indicating circuit 4 sets the R signal to "1" and causes the tape to run to the right, so that side A is reproduced.

In contrast to the above, when the B side is inserted into the front side, the switch _S1 is off, so the signal A/B is "0". Therefore, when the signal DET becomes "1", the output L' of the AND gate _A2 becomes "1", instructing the vehicle to run to the left. Therefore, in this case as well, side A is played back.

The display control circuit 6 comprising transistors Q ₂ to Q ₅ , diodes D ₁ to D ₄ , and inverters I ₁ and I ₂ and the reproduction display circuit 7 comprising light emitting diodes LED-A and LED-B operate as follows. . These circuits combine the on/off of the switch _S1 and the "1" and "0" of the left and right running signals L and R to set only one of the inputs of the diodes _D1 to _D4 to "1", and to set the two inputs to "1". Diode D ₁ ,
Of the inverters I ₁ and I ₂ to which the outputs of the group D _{4 and} the group D _{2 and D 3} are connected, turn on LED-A or LED-B connected to the inverter whose output is “0”. It is something. For example, when switch S ₁ is turned on, transistor Q ₁ is turned on, transistors Q ₂ and Q ₄ are turned off, and transistors Q ₃ and Q ₅ are turned on. At this time, if the right running signal R is "1" and the left running signal L is "0", only the input of diode _D1 becomes "1", and the inputs of all other diodes _D2 to _D4 become "0". Therefore, the output of the inverter _I2 becomes "1" and the output of the inverter _I1 becomes "0", and the light emitting diode LED-A lights up. this
LED-A is a display element that indicates the performance of side A.
At this time, if the left running signal L is "1" and the right running signal R is "0", only the input of diode _D3 is "1".
Therefore, the output of the inverter _I2 becomes "0" and the light emitting diode LED-B lights up. This LED
-B is a display element that shows the performance of side B.

On the other hand, when switch _S1 is turned off, the transistor
Since Q ₁ is turned off, transistors Q ₃ and Q ₅ are turned off, and transistors Q ₂ and Q ₄ are turned on. Therefore, when the signal R is "1" and the signal L is "0", only the input of the diode _D2 is "1", so the output of the inverter _I2 becomes "0" and LED-B lights up. Conversely, if signal R is "0" and signal L is "1", only the input of diode _D4 will be "1".
LED-A lights up.

The above is a general display operation, and only LED-A lights up when the pack is inserted. Furthermore, the detection signal
When DET returns to "0" after a certain period of time, the driving direction indicating circuit 4 will send signals R and L if there are no other inputs.
is retained for side A playback. However, if there are other inputs such as FF, REW, etc., then follow the instructions for R, L.
change. Furthermore, although the above example shows the initial setting circuit for A-side reproduction, in order to reproduce B-side, the outputs of AND gates A ₁ and A ₂ must be crossed and input to the instruction circuit 4, or transistors Q ₆ , It is sufficient to cross the output of Q ₇ and apply it to each first input of AND gates A ₁ and A ₂ . Furthermore, if the outputs of transistors Q ₆ and Q ₇ change after the pack insertion detection signal DET becomes "1", the outputs of transistors Q ₆ and Q ₇ before that change will come out from AND gates A ₁ and A ₂ . So,
To avoid this, switch the operation of Switch S ₂
S slower than ₁ or in other ways to detect the signal
It is necessary to slow down the rise of DET.

FIG. 4 is a circuit diagram showing another embodiment of the present invention. In this example, switch _S1 is turned off when side A is detected and turned on when side B is detected, contrary to FIG. Since the display control circuit 6 and the playback surface display circuit 7 have the same configuration, the A side,
An inversion transistor _Q8 is added to the B-side detection circuit 1. On the other hand, for this reason, the transistors Q ₆ and Q ₇ of the initial setting circuit 3 become unnecessary. OR ₁ , OR ₂
is an OR gate corresponding to the wired OR in FIG. 3, and Q ₉ and Q ₁₀ are transistors forming inverters I ₁ and I ₂ . Since the other configurations and operations are the same as those in FIG. 3, their explanations will be omitted.

[Effect of idea]

As described above, according to the present invention, no matter which side of the cassette pack is inserted with the front facing up, playback can always be performed from a fixed side.Especially in the case of an auto-reverse type cassette deck for use in a car, the driver can This has the advantage that it can be determined without visually checking indicators, etc., and does not interfere with stable driving.

[Brief explanation of the drawing]

FIG. 1 is a basic block diagram of the present invention, FIG. 2 is an explanatory diagram of pack insertion detection, and FIGS. 3 and 4 are circuit diagrams showing each embodiment of the present invention. In the figure, 1 is the A side and B side detection circuit, 2 is the pack insertion detection circuit, 3 is the initial setting circuit, 4 is the travel direction indicating circuit, 5 is the cassette pack, _S1 is the A side and B side detection switch, S ₂ is pack insertion detection switch, MM
is a monostable multivibrator, and A ₁ and A ₂ are AND gates.

Claims (1)

[Scope of utility model registration request] A pack insertion detection circuit detects the insertion of a cassette pack and outputs a detection signal for a certain period of time; a side A/side B detection circuit detects which side of the pack is inserted with the front side; A side, B
An auto-reversing type cassette deck characterized by comprising a running direction indicating circuit which receives an output from a face detection circuit, determines the running direction of the tape in which a preset face is played back, and controls the running direction of the tape. Playback surface setting circuit when inserting a pack.