JPH0319111Y2 - - Google Patents

Description

[Detailed Description of the Invention] [A. Field of Industrial Application] The present invention relates to a tape recorder with a radio, and particularly relates to a tape recorder with a radio equipped with a noise reduction circuit in the tape recorder section.

[B. Conventional technology]

Radio tape recorders equipped with noise reduction circuits are known. The circuit shown in FIG. 1 was a common circuit for a radio tape recorder equipped with such a noise reduction circuit. In Fig. 1, 1 is a radio section, 2 is a tape recorder section, 3 is an antenna constituting the radio section 1 , and 4 is also the radio section 1.
5 is an FM multiplex demodulation circuit that also constitutes the radio section 1 ;
6 is a magnetic head that constitutes the tape recorder section 2 ; 7 is an equalizer circuit that also constitutes the tape recorder section 2 ; 8 is a noise reduction circuit provided in the tape recorder section 2 ; 9 is a power supply section; 10 is a first
When the switch is operated, the power supply voltage (+B) from the power supply section 9 is selectively applied to the radio section 1 or the tape recorder section 2 . 11 is FM
This is a second switch for switching between monaural and FM stereo, and when FM monaural is selected, the power supply voltage (+B) from the power supply section 9 is applied to the FM multiplex demodulation circuit 5, and the FM multiplex demodulation circuit 5 is set to the monaural state. . 12 is the noise reduction circuit 8
This is a third switch for ON/OFF control, and when the tape recorder section 2 is selected by the first switch 10, when it is switched to the OFF position, the power supply section 9
Turn off the power supply voltage (+B) and the noise reduction circuit 8.
voltage is applied to the terminal, and the noise reduction circuit 8 is turned off.

Next, the operation of such a circuit will be explained.

Now, if the first switch 10 is switched to the radio Ra side, the power supply voltage (+B) is applied from the power supply section 9.
It is applied to the AM/FM receiving section 4 and the FM multiplex demodulation circuit 5.
The FM multiplex demodulation circuit 5 becomes active. At this time, if the second switch 11 is on the stereo side, FM stereo broadcasting can be received. When the second switch 11 is switched to the monaural (MONO) side in such a state, the power supply voltage (+B) of the power supply section 9 is changed to the first switch 10, the resistor 13 and the second switch 11.
Since the signal is applied to the FM multiplex demodulation circuit 5 via the switch 11, the FM multiplex demodulation circuit 5 is forcibly switched to a monaural state.
FM monaural reception status is established.

When the first switch 10 is switched to the tape recorder Ta side, the supply of power supply voltage (+B) to the radio section 1 is stopped, so the AM/FM receiving section 4 and
The FM multiplex demodulation circuit 5 becomes inactive. At the same time, the power supply voltage (+B) is applied from the power supply section 9 to the equalizer circuit 7 and the noise reduction circuit 8 of the tape recorder section 2 , and the equalizer circuit 7 and the noise reduction circuit 8 become active. Therefore, for example, when a reproduction operation is performed, information recorded on a tape (not shown) is read out by the magnetic head 6, and the read signal is processed by the equalizer circuit 7 and the noise reduction circuit 8, and then Leads to the subsequent circuit.
At this time, if the third switch 12 is on the ON side, the noise reduction circuit 8 is in an operating state and reduces noise such as hiss noise contained in the signal applied via the equalizer circuit 7. When the third switch 12 is turned OFF in such a state, the power supply voltage (+B) is applied from the power supply section 9 to the noise reduction circuit 8 via the first switch 10, the third switch 12, and the resistor 14.
Since the voltage is applied to the OFF terminal, the noise reduction circuit 8
It becomes OFF, and the output signal of the equalizer circuit 7 is guided to the subsequent circuit. In this way the operation of such a circuit is achieved.

Incidentally, recently, small and lightweight tape recorders (so-called headphone stereos) that only have a tape playback function have been commercialized, but as devices become more multifunctional, headphone stereos are also equipped with not only a tape playback function but also a radio. Alternatively, devices with a noise reduction circuit or even a recording function have been proposed.

However, in terms of operability, such a headphone stereo has a limitation in that the operating section must be placed on the top of the device and on the side of the device near the operating mechanism.

Therefore, if the device is simply made multi-functional as described above, there is a risk that the operability will deteriorate.

[C. Purpose of the invention]

The present invention proposes a tape recorder with a radio that can increase the functionality of the device without reducing operability and can reduce the number of parts.

[D. Summary of the idea]

A radio section including an FM multiplex demodulation circuit, a tape recorder section including a noise reduction circuit,
A power supply section that generates a power supply voltage, a first switch for selectively supplying the power supply voltage from the power supply section to the radio section or the tape recorder section, and an FM multiplex demodulation circuit for the power supply voltage from the power supply section. and a second switch for controlling the supply to the noise reduction circuit, and when the first switch is set to supply the power supply voltage to the radio unit, the power supply voltage is controlled by the switching operation of the second switch. When the FM multiplex demodulating circuit is set to a monaural state in accordance with power supply to the FM multiplex demodulating circuit, and the first switch is set to supply power voltage to the tape recorder section, the first switch The above object is achieved by setting the noise reduction circuit to a non-operating state in response to power supply to the noise reduction circuit by switching the two switches.

[E Example]

FIG. 2 is a diagram showing an embodiment of the present invention. Second
In the figure, 20 is a second switch, and when the first switch 10 is on the radio Ra side, it selects the function of the radio section 1 (specifically, when it is on the a side, it is FM monaural, and when it is on the b side, it is FM stereo. ), and when the first switch 10 is on the tape recorder Ta side, the tape recorder section 2
(Specifically, when it is on the a side, the noise reduction circuit 8 is turned off, and when it is on the b side, the noise reduction circuit 8 is turned on.) being done.

Next, the operation of such a circuit will be explained.

Now, assuming that the first switch 10 is on the radio Ra side, the power supply voltage (+B) is applied from the power supply section 9 to the AM/FM reception section 4 and the FM multiplex demodulation circuit 5 of the radio section 1 , and the AM/FM reception Part 4
And the FM multiplex demodulation circuit 5 becomes active. At this time, if the second switch 20 is on the b side, the radio unit 1 is in a state where it can receive FM stereo broadcasts. When the second switch 20 is switched to the a side in this state, the power supply voltage (+B) is applied from the power supply unit 9 to the FM multiplex demodulation circuit 5 of the radio unit 1 via the resistor 21, the second switch 20, and the resistor 22. Then, the FM multiplex demodulation circuit 5 is forcibly switched to the monaural state, and the FM monaural reception state is established.

In this state, when the first switch 10 is switched to the tape recorder Ta side, the AM/FM of the radio section 1
Since the supply of power supply voltage (+B) to the receiving section 4 and FM multiplex demodulation circuit 5 is stopped,
The AM/FM receiving section 4 and the FM multiplex demodulation circuit 5 become inactive. At the same time, the power supply section 9
The power supply voltage (+B) is then applied to the equalizer circuit 7 and noise reduction circuit 8 of the tape recorder section 2 via the first switch 10. At this time, since the second switch 20 is on the a side, the power supply voltage (+B) is applied from the power supply section 9 to the OFF terminal of the noise reduction circuit 8 via the resistor 21, the second switch 20, and the resistor 23. , the noise reduction circuit 8 is in an off state.
Therefore, for example, when a reproduction operation is performed in such a state, the signal recorded on the tape is read out by the magnetic head 6, and the read signal is sent to the equalizer circuit 7.
It is then guided to the subsequent circuit. When the second switch 20 is switched to the b side in such a state, the supply of power supply voltage (+B) to the OFF terminal of the noise reduction circuit 8 is cut off, so the noise reduction circuit 8 becomes active.
Noise such as hiss noise included in the signal output from the equalizer circuit 7 is reduced.

[F Application example]

FIG. 3 is a diagram showing an application example of the present invention, in which a light emitting diode 30 is connected between one terminal of the second switch 20 and the ground.
is connected. In this circuit, when the FM stereo or noise reduction circuit 8 is turned on, the light emitting diode 30 is turned on.

It goes without saying that the present invention is not limited to headphone stereos.

[G Effect of the idea]

A switch is provided that allows you to select the function (or operation) corresponding to each source when selecting a radio or tape recorder, allowing for diversification of functions without deteriorating operability or increasing the number of parts. can be measured. Furthermore, when providing display means for displaying functions, for example, the number of parts can be reduced compared to the conventional method.

Furthermore, since the power supply voltage from the power supply section is used as the operation control voltage for the FM multiplex demodulation circuit and the noise reduction circuit, the circuit configuration can be simplified.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a conventional example, FIG. 2 is a diagram showing an embodiment of the present invention, and FIG. 3 is a diagram showing an applied example. 1 ...Radio section, 2 ...Tape recorder section,
10...first switch, 20...second switch.

Claims (1)

[Scope of utility model registration request] a radio section including an FM multiplex demodulation circuit; a tape recorder section including a noise reduction circuit;
a power supply unit that generates a power supply voltage; a first switch that selectively supplies the power supply voltage from the power supply unit to the radio unit or the tape recorder unit; and a first switch that selectively supplies the power supply voltage from the power supply unit to the radio unit or the tape recorder unit; and a second switch for selectively supplying power to an FM multiplex demodulation circuit or a noise reduction circuit, and when the first switch is set to supply power voltage to the radio section, the second switch The FM multiplex demodulation circuit is set to a monaural state in response to the voltage supplied to the FM multiplex demodulation circuit by switching the switch, and the first switch is set to supply power voltage to the tape recorder section. A tape recorder with a radio, wherein the noise reduction circuit is set to a non-operating state in response to voltage supply to the noise reduction circuit by switching the second switch.