JPH0341288Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an in-vehicle tape deck, and more specifically, relates to an in-vehicle tape deck that automatically cancels play when the power is turned off during tape play. It is.

[Background of the idea]

Tape decks are used to play back or record magnetic tapes, and most of the tape decks installed in cars are for playback only.In the tape play mode, a pinch roller is used to move the magnetic tape onto a capstan that is rotating at a constant speed. By pressing, the magnetic tape is made to run at a constant speed.

Therefore, this pinch roller is the most important part in running the magnetic tape at a constant speed, and if this pinch roller is deformed, the running of the magnetic tape becomes unstable and wow and flutter occurs.

However, in conventional tape decks such as car stereos, when the power switch is turned off while in the play state, the play state is mechanically maintained, so the pinch roller remains pressed against the capstan. When this condition lasts for a long time, the capstan becomes deformed and the magnetic tape sandwiched between the capstan and the pinch roller is also damaged.

[Purpose of invention]

Therefore, an object of the present invention is to prevent the pinch roller from deforming by automatically canceling the play state when the power is turned off while the tape is still in the play state.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a circuit diagram showing an embodiment of an in-vehicle tape deck according to the present invention, in which reference numeral 1 indicates the tape deck, which has a power supply terminal + _B1 , a backup power supply terminal + _B2 , and a play release terminal IN. There is. And power terminal +B ₁ is power switch 2
is connected to the positive pole of the power supply 3 via
The backup power supply terminal + _B2 is directly connected to the positive terminal of the power supply 3. Further, reference numeral 4 inputs the output of the power switch 2, detects that the power switch 2 is off and the tape deck 1 is turned off, and supplies a play release signal PR to the play release terminal IN of the tape deck 1. The tape play release circuit is shown.

In this case, it is assumed that the tape deck 1 has a tape deck control system, as shown in FIG. 2, for example. In FIG. 2, reference numerals 5 to 7 are non-lock type switches for controlling FF, play, and rewind, and the outputs of the switches 5 to 7 are electrically locked in the deck controller 8. , transistors 9-11 corresponding to this lock signal are turned on, and solenoids 12-14 for fast forward, play, and rewind are energized. In this case, tape deck 1 does not use the rotational force of the capstan to run the magnetic tape during fast forwarding and rewinding, but rather releases the magnetic tape from the capstan and pinch roller, in other words, releases the play. This allows the magnetic tape to run freely. Therefore, the play state can be easily canceled by energizing the fast-forward or rewind solenoids 13 and 14.

Figure 3 shows the tape play release circuit 4 shown in Figure 1.
The output of the power switch 2 shown in FIG. 1 is supplied to a quick charge/long time discharge time constant circuit 18 composed of a diode 15, a capacitor 16, and a resistor 17. The output of this time constant circuit 18 is then supplied to a hysteresis gate 20 via a resistor 19. The output signal of this hysteresis gate 20 changes with a delay with respect to the input signal. Reference numeral 21 is a NAND gate which receives the output of the hysteresis gate 20 and the play output signal PL of the deck controller 8 shown in FIG. 23, which outputs an "H" output in reverse for a fixed period of time determined by the values of resistor 24; 25 is the set output of mono multi 22 and the output from deck controller 8 shown in FIG. Fast forward and rewind control signals FF, REW
This is an inverter that inverts the output and supplies it to the FF or rewind solenoids 12 and 14.

In the in-vehicle tape deck constructed as described above, when the power switch 2 is turned off in the playing state, the power is turned off as shown in FIG. 4a. When the power is turned off, the output of the time constant circuit 18 shown in FIG. 3 gradually decreases as shown in FIG.
The output of 0 also becomes "L". In this case, since the play control signal PL output from the deck controller 8 shown in FIG. 2 maintains the "H" level as shown in FIG. At the time when the output changes to "L", it becomes "H", and accordingly, the monomulti 22 is set. As shown in FIG. 4d, this monomulti 22 has a time constant γ determined by the values of the capacitor 23 and the resistor 24.
It sends out an "H" output for a period of time corresponding to . The "H" output of this monomulti 22 is sent via the NOR gate 25 and the inverter 26 to send a pulse of a certain time width as a play release signal as shown in FIG. 4e.
It is supplied as PR to the play release terminal IN of the tape deck 1 shown in FIG.

In this way, when the play release signal PR in the form of a pulse with a constant time width is supplied to the play release terminal IN from the tape play release circuit 4 to the tape deck 1, the backup power supply supplied to the backup power supply terminal + _B2 is Therefore, the fast-forward or rewind solenoids 12 and 14 shown in FIG. 2 are energized. As a result, the tape deck 1 automatically enters the play release state, and the pinch roller is released from being pressed against the capstan.

Note that in a deck controller configured to take the timing of output pulses using a counter, an R-S latch circuit or flip-flop is used instead of a monomulti, and after outputting the play release signal PR, the clock oscillation is started. The circuit may be configured to be stopped.

[Effect of idea]

As is clear from the above explanation, the in-vehicle tape deck according to the present invention is provided with a tape play release circuit that detects that the power is turned off in the play state and generates a play release signal, and outputs the tape play release circuit. Since the tape play state is automatically canceled by activating the fast forward or rewind solenoid using the backup power supply, the pinch mode can be automatically canceled even if the power is turned off during the play state. The roller can be separated from the capstan, and deformation of the pinch roller can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the in-vehicle tape deck according to the present invention, Fig. 2 is a circuit diagram showing the control system of the in-vehicle tape deck used in Fig. 1, and Fig. 3 is the tape deck shown in Fig. 1. A circuit diagram showing an example of a play release circuit, and FIGS. 4a to 4e are waveform diagrams of various parts for explaining the operation of FIG. 3. 1... Tape deck, 2... Power switch, 3
...Power supply, 4...Tape play release circuit.

Claims (1)

[Claims for Utility Model Registration] A tape play release circuit that detects whether the power of the main body of the device is turned on or off during the play mode, and outputs a release signal to release the play mode when the power is detected to be turned off; Power is supplied from the backup line directly connected to the battery and the battery through the power switch of the device main body, and when the tape play release circuit outputs a release signal, the solenoid is actuated by the power from the backup power supply. 1. A tape deck for use in a vehicle, comprising: a tape deck control section for canceling the play mode by canceling the play mode.