JPH05183453A - Electronic device - Google Patents

Abstract

PURPOSE:To send a modulated audio signal as required with simple configuration by supplying an audio signal and its modulated audio signal to an external output terminal and sending the modulation audio signal to an external output terminal only when a transmission output section is loaded. CONSTITUTION:A headphone amplifier 4 amplifies a reproduced audio signal S1 and sends its output audio signal S2 to a headphone Jack 5 via a coupling capacitor C and a matching coil L. The user listens to the reproduced audio signal by plugging in a plug of the headphone to the headphone jack 5. In the case of a tape recorder 1, the signal S1 is inputted to a modulation circuit 6 through a buffer 2, modulated by the modulation system in matching with the wireless system by FM modulation and infrared ray, the modulation output S3 is amplified by an output drive circuit 7 and the result is outputted to the jack 5 as a modulated audio signal S4. When a wireless plug 10 is loaded, the signal S4 is outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device, and is suitable for application to, for example, a small tape recorder.

[0002]

2. Description of the Related Art Conventionally, in a headphone stereo as a small-sized tape recorder, there is a headphone that is wireless, and it is possible to prevent cords from getting in the way and improve the usability of the user. There is something done.

[0003]

However, some headphone stereos having such a configuration have a transmitter, a transmitting antenna, and an infrared output transducer built-in in response to the shift to wireless. Since the antenna and the transformer are arranged on the stereo body, there is an unavoidable problem that hinders miniaturization.

For this reason, instead of the structure in which the transmitter is built in the headphone stereo main body, there is a device in which the transmitter is attached to the headphone output terminal only when the wireless headphone is used. The transmitter itself was relatively large, and it was still insufficient in terms of user friendliness.

The present invention has been made in view of the above points, and it is an object of the present invention to propose an electronic device that can send a modulated audio signal through an external output terminal for an audio signal as needed with a simple structure. .

[0006]

In order to solve such a problem, according to the present invention, in an electronic device 1 having an external output terminal 5 for an audio signal S2, an audio signal S1 is used.
Is modulated by a predetermined modulation method, and the modulated audio signal S
Modulation output means 6 and 7 for supplying 4 to the external output terminal 5,
A transmission control unit 8 is provided which detects whether or not a predetermined transmission output unit 10 is attached to the external output terminal 5, and transmits the modulation audio signal S4 from the modulation output units 6 and 7 only when the transmission output unit 10 is attached. I chose

[0007]

In the external output terminal 5 of the audio signal S2, in addition to the audio signal S2, the audio signal S1 is modulated by the modulation output means 6 and 7.
4 and the modulation output means 6 and 7 are provided only when a predetermined transmission output unit 10 is attached to the external output terminal 5.
Since the modulated audio signal S4 is transmitted from the device, the predetermined transmission output unit 10 can be attached as necessary to transmit the modulated audio signal S4, thus improving the usability for the user.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a small tape recorder according to the present invention as a whole, and a reproduced audio signal S1 obtained by reproducing an audio tape (not shown) is passed through a buffer amplifier 2 and a semi-fixed resistor 3 for level adjustment. Input to headphone amplifier 4.

The headphone amplifier 4 amplifies the reproduction audio signal S1 to a predetermined level, and the resulting output audio signal S2 is sent to the headphone jack 5 through the coupling capacitor C and the matching coil L.

Thus, the user can attach a plug of a headphone (not shown) to the headphone jack 5 so that the reproduced audio signal can be heard through the headphone as in a normal headphone stereo.

Further, in the case of the tape recorder 1, the reproduction audio signal S1 is inputted to the modulation circuit 6 through the buffer 2 and is modulated by the modulation system which is in conformity with the FM system and the wireless system by the infrared ray, and the resulting modulation output S3 is obtained. It is amplified by the output drive circuit 7 and sent to the headphone jack 5 as a modulated audio signal S4.

Here, this output drive circuit 7 is a modulation audio device, for example, when a headphone plug is attached, in accordance with an output signal S5 from a headphone detection circuit 8 which detects the plug type attached to the headphone jack 5. When the output of the signal S4 is stopped and the wireless plug 10 as shown in FIG. 2 is attached, the modulated audio signal S4
It is designed to send out.

The wireless plug 10 shown in FIG.
As shown in FIG. 2 (A), an antenna 12 is connected to a plug 11 for an FM modulation wireless system, and FIG.
As shown in FIG.
There is a wireless system using infrared connected.

There is also a wireless headphone corresponding to this, and as shown in FIG. 3A, in a wireless headphone 20 for a wireless system by FM modulation, a received signal is demodulated by a demodulation circuit 21 and this demodulation is performed. The signal S10 is amplified by the headphone amplifier 22, and this reception audio signal S11 is sent to the headphone 23.

Further, as shown in FIG. 3B, in the wireless headphone 30 for infrared wireless system, the light receiving signal of the infrared photodiode 31 is demodulated by the demodulation circuit 32, and the demodulated signal S12 is headphone amplifier 22. After being amplified, this reception audio signal S13 is sent to the headphone 23.

As a result, in the case of this tape recorder 1,
If the wireless plug 10 is attached to the headphone jack 5 instead of the headphone plug and the headphone 23 of the wireless headphones 20 and 30 is attached, the reproduced audio signal can be easily heard by the wireless system.

In practice, the headphone amplifier 4, the output drive circuit 7 and the headphone detection circuit 8 of the tape recorder 1 are constituted by circuits as shown in FIG.
That is, the reproduction audio signals S1R and S1L composed of the right and left channels are input to and amplified by the headphone amplifiers 4A and 4B, respectively.

The resulting output audio signal S2
R and S2L are input to the right and left channel ends R and L of the headphone jack 5 through coupling capacitors C1 and C2 and matching coils L1 and L2. The ground terminal G of the headphone jack 5 is grounded through the matching coil L3.

This output drive circuit 7 is of a wireless type using infrared rays and has four transistors Q1 and Q1.
A modulation output S3, which is composed of 2, Q3, Q4 and a resistor and is sent from the modulation circuit 6, is amplified by the transistors Q3 and Q4 and input to the right channel end R of the headphone jack 5 as a modulation audio signal S4. The transistor Q1 is connected to the left channel end L of the headphone jack 5.

As a result, when the headphone jack 5 is fitted with a stereo headphone plug, the transistors Q1 and Q2 are immediately connected to the transistors Q3 and Q4.
The operation is stopped so that the modulated audio signal S4 is not sent out. Conversely, when the wireless plug 10 for monaural is attached, the modulated audio signal S4 is sent out.

According to the above-mentioned structure, the modulated audio signal S depends on the plug attached to the headphone jack 5.
By automatically determining whether or not to send 4, the need for a switch or the like for setting whether or not to use the wireless headphones 20, 30 can be reduced, and the overall size can be reduced and the modulation can be performed. By incorporating the circuit 6 and the output drive circuit 7, it is possible to realize the tape recorder 1 in which the configuration of the wireless plug 10 can be made small and simple.

Further, according to the above construction, the wireless headphones 20 and 30 can be used by a simple operation only by mounting the wireless plug 10, and there is no need to perform a switch operation of the main body on the side of the main body. As a result, it is possible to realize the tape recorder 1 that can significantly improve the usability for the user.

In the above-mentioned embodiment, the case where the wireless system using FM modulation and infrared rays is used is described. However, the effect similar to that of the above-mentioned embodiment can be realized even if only one of them is used. The present invention can be applied to other wireless systems such as ultrasonic waves instead of the wireless system.

Further, in the above-described embodiment, whether or not the wireless headphone is used is detected by the type of the plug attached to the headphone jack, but the present invention is not limited to this, and the shape of the wireless plug is not limited to this. May be detected by changing the shape of the headphone plug, and the point is that if it is possible to easily detect whether or not to use a wireless headphone, even if various methods are applied, the same as in the above-described embodiment. The effect of can be realized.

Further, although the present invention is applied to the tape recorder in the above-mentioned embodiment, the present invention is not limited to this,
For example, it is suitable for wide application to electronic devices having an external output terminal for outputting an audio signal, such as a radio receiver, a television receiver, and an optical disc device.

[0027]

As described above, according to the present invention, in addition to the audio signal, the modulated audio signal obtained by modulating the audio signal by the modulation output means is supplied to the external output terminal of the audio signal and the external output terminal is supplied to the external output terminal. By transmitting the modulation audio signal from the modulation output means only when the predetermined transmission output unit is attached, the predetermined transmission output unit can be attached to transmit the modulation audio signal as necessary, Thus, it is possible to realize an electronic device that can improve the usability for the user.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a tape recorder according to the present invention.

FIG. 2 is a schematic diagram showing a wireless plug mounted on the tape recorder of FIG.

FIG. 3 is a block diagram showing a wireless headphone corresponding to a wireless plug in FIG.

4 is a connection diagram showing a circuit configuration of a main part of the tape recorder of FIG. 1. FIG.

[Explanation of symbols]

1 …… tape recorder, 2 …… buffer, 4,22 ……
Headphone amplifier, 5 ... Headphone jack, 6 ...
Modulation circuit, 7 ... Output drive circuit, 8 ... Headphone detection circuit, 10 ... Wireless plug, 11 ... Plug, 12 ... Antenna, 13 ... Infrared light emitting diode, 20, 30 ... Wireless headphone, 21, 32
...... Demodulation circuit, 23 ...... Headphones, 31 ...... Infrared photo diode.

Claims (1)

[Claims] 1. An electronic device having an external output terminal for an audio signal, comprising: modulation output means for modulating the audio signal by a predetermined modulation method and supplying the modulated audio signal to the external output terminal; and the external output terminal. An electronic device comprising: a transmission control unit that detects whether or not a predetermined transmission output unit is attached to the device, and sends out the modulated audio signal from the modulation output unit only when attached.