JPS6343828B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a key-off eject type tape recorder control circuit configured to automatically eject a tape cassette when the main switch is turned off, and its purpose is simple. To provide a control circuit for a tape recorder which can surely eject a tape cassette when a main switch is turned off even when the tape is running at high speed with a simple structure.

Generally, a car-mounted tape recorder enters a tape playback state when a tape cassette is attached to the tape recorder main body, and during this tape playback operation, the power supply is often turned off, that is, the car's engine key is turned off. In such a case, if the tape cassette remains attached to the tape recorder, the pinch roller will remain in pressure contact with the capstan shaft for a long time, causing deformation of the pinch roller, and the tape will be removed when the engine key is turned off. A method has been adopted in which the cassette is automatically ejected or keyed off. In such a key-off eject type tape recorder, when the engine key is turned off or an eject button is operated, a trigger mechanism is activated by a plunger, and the motor is connected to the eject mechanism by this trigger mechanism. It is known that the eject mechanism is driven using the rotational force of the motor, and the eject mechanism removes the tape cassette from the mounting position of the tape recorder main body. On the other hand, in this type of tape recorder,
In order to reduce the number of operation buttons when adding a high-speed driving mode such as FF or REW, the above plunger can be used in common so that when the eject button is operated, the high-speed driving mode is canceled and the mode is switched to the regeneration mode. is being carried out. However, in a key-off eject type tape recorder with a high-speed running mode added as described above, if the tape running mode is in the playback mode when the engine key is turned off, the key-off eject can be performed using the plunger. There is no problem with this, but when it is in high-speed running mode, the plunger can only be used to switch to regeneration mode and cannot be ejected. Also, there is no guarantee that the user will always eject the engine key before turning off the engine key.
In high-speed running mode, the tape cassette cannot be ejected, and the tape cassette remains attached to the tape recorder body. At this time, the pinch roller remains pressed against the capstan shaft for a long time. There was a problem that if left untreated, the pinch roller would become deformed.

The present invention eliminates such conventional drawbacks, and the present invention will be described below with reference to drawings of embodiments.

FIG. 1 shows an embodiment of a control circuit for a tape recorder according to the present invention. In FIG. 1, 1 is a car battery, S ₁ is an engine switch, S ₂ is a stop/eject switch, and S ₃ is a stop/eject switch. 2 is a switch that is turned on and off in response to the attachment and detachment of the tape cassette from the tape recorder body, and 2 is a plunger used to change modes from high-speed running mode to playback mode and from playback mode to eject mode. . Q ₁ to Q ₇ are transistors, and the base of the transistor Q ₁ is grounded by a resistor R ₁ and connected to the positive pole of the battery 1 via a diode D ₁ and a resistor R ₁₁ of the engine key switch S. ₁ , and the collector of its transistor Q ₁ is connected to the base of transistor Q ₂ . The emitter of the transistor _Q2 is grounded together with the emitter of the transistor _Q1 , and the collector of the transistor _Q2 is connected via a resistor _R3 to the base of a transistor _Q4 , which has a resistor _R5 inserted between its base and emitter. There is. The base of the transistor Q ₂ is connected to a switch S ₃ connected to the positive terminal of the battery 1 via a resistor R ₂ , and the base of the transistor Q 2 is
The emitter of Q ₄ is similarly connected to the switch S ₃ above. The collector of the transistor Q ₄ is connected to the base of the transistor Q ₆ via the diode D ₂ and the capacitor C ₃ , and the diode D ₂ and the base of the transistor Q ₆ are grounded through resistors R ₉ and R ₁₀ , respectively. has been done. The emitter of the transistor Q ₆ is connected to the base of a transistor Q ₇ whose emitter is grounded, and the collectors of the transistors Q ₆ and Q ₇ are connected to the switch S ₃ via the plunger 2. On the other hand, the collector of transistor Q ₄ is grounded via resistor R ₈ and capacitor C ₁ , and the connection point between resistor R ₈ and capacitor C ₁ is connected to transistor Q ₃ whose emitter is grounded.
The base of the transistor _Q3 is grounded through a resistor _R7 . The collector of the transistor _Q3 is connected via a resistor _R4 to the base of a transistor Q5, which has a resistor _R4 inserted between its emitter and base, and whose emitter is connected to the collector of _the transistor _Q4 .
The collector of the transistor Q ₅ is grounded through a resistor R ₁₂ and connected to the base of the transistor Q ₆ via a capacitor C ₂ .

In a tape recorder having such a configuration, if the engine key switch _S1 is turned on, the tape cassette is attached to the tape recorder body, and the switch _S3 is turned on, the base of _the transistor _Q1 is turned on through the diode D1. Because it is biased, transistor Q ₂ is off, transistor Q ₄ is off, transistors Q ₃ and Q ₅ are also off, and transistors Q ₆ and Q ₇ are also off. In this state, if you manually operate Switch S ₂ ,
A pulse is applied to the base of the transistor Q ₆ by a differentiating circuit consisting of a capacitor C ₃ and a resistor R ₁₀ , so that transistors Q ₆ and Q ₇ are turned on and the plunger 2 can be driven. When in the high-speed running mode, the plunger 2 can be manually operated to switch to the regeneration mode.
When in the playback mode, the tape cassette can be ejected by means of the plunger 2 which is manually operated. On the other hand, when the engine key switch _S1 mentioned above is turned from the on state to the off state,
Manually operated switch _S2 has no effect on transistor _Q6 , and diode _D1 no longer applies bias to the base of transistor _Q1 , turning transistor _Q1 off.
Therefore, the transistors Q ₂ and Q ₄ are turned on, and the capacitor C ₃ and the resistor R ₁₀ are connected through the diode D ₂ .
As shown in FIG. 2a, a pulse is outputted from the differentiating circuit consisting of the following, and this pulse is applied to the base of the transistor Q ₆ , turning on the transistors Q ₆ and Q ₇ and driving the plunger 2. When the plunger 2 is driven, the tape cassette can be ejected by the plunger 2 if it is in the tape playback mode, and this ejection operation turns off the switch S ₃ and turns off the transistors Q ₂ and Q ₄ . Transistors Q ₂ and Q ₄ are turned off because there is no power supplied to them. and,
When the plunger 2 is driven when the engine key switch S ₁ is turned off, if the tape is in high-speed running mode, the differential pulse generated when the transistor Q ₄ is turned on is activated as shown in Figure 2b. Transistors Q ₆ and Q ₇ are then turned on and plunger 2 is driven, allowing a switch to the playback mode. However, even with this mode switch, the tape cassette has not been ejected, so switch S ₃ continues to be on. Therefore, transistors Q ₂ and Q ₄ are in the on state. Therefore, the capacitor _C1 is gradually charged through the resistor _R8 and finally turns on the transistor _Q3 .
Transistor Q ₅ is turned on, and a pulse is output from the differentiator circuit consisting of capacitor C ₂ and resistor R ₁₀ .
This pulse turns on transistors Q ₆ and Q ₇ and drives the plunger 2 again.
This plunger 2 allows the tape cassette to be ejected from the playback mode. If the plunger is ejected at the first plunger operation, the pulse will not be output again to drive the plunger because the switch _S3 is off.

In the above embodiment, an in-vehicle tape recorder has been described, but it goes without saying that this can also be applied to a normal tape recorder, and in this case, the engine key switch may be replaced with a power switch.

As described above, according to the present invention, in a tape recorder configured to share a plunger for mode switching from playback mode to eject mode in order to switch from high-speed running mode to playback mode, the main switch is A first pulse generating means generates a pulse to drive the plunger when turned off, and the power supply to the first pulse generating means is turned on and off in response to the operation of attaching and detaching the tape cassette to and from the tape recorder main body. A second pulse generating means is provided which generates a pulse after a predetermined period of time when the main switch is turned off and drives the plunger again, so that the tape mode is changed when the main switch is turned off. The tape cassette can be automatically ejected in both playback mode and high-speed running mode, which prevents the pinch roller from deforming if the tape cassette is left attached to the tape recorder body. It is something that can provide a tape recorder that is not available.

[Brief explanation of the drawing]

FIG. 1 is a circuit connection diagram showing an embodiment of a control circuit for a tape recorder according to the present invention, and FIGS. 2a and 2b are diagrams illustrating its operation. 1...Battery, 2...Plunger, S ₁ ...
...Engine key switch, S ₂ ...Stop/eject switch, S ₃ ...Switch, Q ₁ to _{Q 7}
...Transistor.

Claims (1)

[Claims] 1. It has a mode switching means that automatically ejects the tape cassette by a plunger activated when the main switch is turned off, and the plunger for this mode switching means is used to switch the mode from high-speed running mode to playback mode. A tape recorder configured to be used commonly for the purpose of the present invention includes a first pulse generating means for generating a pulse for controlling the operation of the plunger driving circuit when the main switch is turned off; a second pulse generating means for generating a pulse for controlling the operation of the plunger drive circuit again after the pulse has been generated;
A switch is provided to turn on and off the power supply to the first and second pulse generating means in response to the operation of attaching and detaching the tape cassette to the tape recorder main body, and the mode is changed by the pulse from the first pulse generating means. The tape cassette is automatically ejected by generating a pulse by the second pulse generating means and operating the plunger again when the switch is kept in the on state after the switch is turned on. Characteristic tape recorder control circuit.