JPH0219521B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an audio input selection device that outputs a desired input signal from among a plurality of input signals by switching an input selection switch.

Conventionally, in an audio input selection device in which each output terminal of a radio receiver, tape player, record player, etc. is connected to an input terminal, in order to output an input signal from the radio receiver, the input of the audio input selection device is After switching the selection switch to "Radio", use the reception frequency band selection switch on the radio receiver to switch the reception frequency band to the desired radio broadcast transmission frequency band, and use the reception frequency tuning switch or dial on the radio receiver to tune the reception frequency band. Since the frequency must be tuned to the desired radio broadcast transmission frequency,
This has the disadvantage that the switching operation procedure in the audio device becomes complicated.

In order to eliminate the drawbacks of the conventional example, the present invention provides an audio system in which the input selection switch is switched to radio input by operating the reception frequency band selection switch, reception frequency tuning switch, or dial of the radio receiver. An input selection device is provided. Examples of the present invention will be described in detail below.

The figure shows the configuration of an embodiment of the present invention.
1 is a radio receiver capable of receiving AM and FM broadcasts, 2 is a receiving antenna of the radio receiver 1, 3 is a radio broadcast receiving circuit of the radio receiver 1, 4 is a tuning circuit of the radio receiver 1, This tuning circuit 4 includes a crystal oscillator 5 and a synthesizer type that outputs a mute signal from an output terminal 6a to the radio broadcast receiving circuit 3 when the reception frequency band is switched or when the reception frequency is tuned to one of the radio broadcast transmission frequencies. It is composed of a phase locked loop integrated circuit 6, a diode group 7, and a switch group 8 consisting of a frequency band changeover switch, a plurality of tuning switches, a tuning switch, and a memory switch. Reference numeral 9 denotes a switching transistor whose base is connected to the output terminal 6a via a level setting resistor 10 and whose emitter is grounded.This transistor 9 is incorporated into the radio receiver 1. 11 is an audio playback device, 12
is an input selection device of the audio playback device 11, and this input selection device 12 has a radio broadcast receiving circuit 3 connected to an input terminal 13a, a tape player (not shown) connected to an input terminal 13b, and a record player (not shown) connected to an input terminal 13c. ) are connected to each other, and the electronic switch circuit 13 uses the input terminal 13d as an auxiliary input, and an integrated circuit for switching outputs a selection signal from the input terminal and the corresponding output terminal when the signal input from the input terminal becomes a low level. 14 and
One side is the input terminal of the integrated circuit 14 and the transistor 9
a switch 15a for radio input connected to the collector of the integrated circuit 14 and grounded at the other end; and a switch 15a for tape playback input connected to the input terminal of the integrated circuit 14 at the other end and grounded at the other end.
b, an input selection switch 1 consisting of a switch 15c for phono input and a switch 15d for auxiliary input;
It consists of 5. 16 is a power amplification circuit of the audio reproduction device 11, and 17 is a speaker.

In this embodiment configured in this way, desired switches 15a and 15 of the input selection switches 15 are selected.
If you press b, 15c or 15d, the integrated circuit 14
Since the corresponding input terminal of the input terminal is grounded and the input terminal becomes a low level, the electronic switch circuit 13 switches to the desired input so that the input signal from the radio input, tape playback input, phono input or auxiliary input becomes electronic. It is output from the switch circuit 13. Also, the reception frequency band of the radio receiver 1 can be changed by using the frequency band changeover switch of the radio receiver 1, or the reception frequency of the radio receiver 1 can be changed by using the channel selection switch or tuning switch of the radio receiver 1. When tuned to the radio broadcast transmission frequency,
A mute signal is output from the phased locked loop integrated circuit 6, making the transistor 9 conductive, so that the input terminal of the integrated circuit 14 is grounded and its input terminal becomes a low level, and the electronic switch circuit 13 is connected to the radio input. Then, the input signal from the radio input is outputted from the electronic switch circuit 13. Note that when the power to the radio receiver 1 is turned off, the transistor 9 becomes non-conductive, so even if the switches in the switch group 8 are operated, the input terminal of the integrated circuit 14 remains at a high level, and the radio input signal is not output. The input signal is no longer output from the electronic switch circuit 13. As explained above, according to the present invention, when you want to listen to the radio, you can simply switch the reception frequency band or tune the reception frequency without performing a switching operation to the radio input, and the input selection means can switch to the radio input. Since the desired radio broadcast can be listened to by automatically switching to the radio input, the procedure for switching to the radio input becomes very simple, and the operability is improved.

[Brief explanation of drawings]

The figure is a circuit diagram showing the configuration of an embodiment of the present invention. 1... Radio receiver, 4... Tuning circuit, 6...
Phase locked loop integrated circuit, 8... switch group, 9... transistor, 12... input selection device, 13... electronic switch circuit, 14... integrated circuit for switching, 15... input selection switch.

Claims (1)

[Claims] 1. For audio equipment that outputs a desired input signal from among a plurality of input signals by switching input selection means to which a plurality of audio devices such as a radio receiver, tape player, record player, etc. are connected. In the input selection device, a tuning circuit of a radio receiver outputs a mute signal when the reception frequency band is switched to a desired radio broadcast transmission frequency band or when the reception frequency is tuned to one of the radio broadcast transmission frequencies; The input selection means outputs the desired input signal by switching the switch circuit when the plurality of input selection switches are operated, and the input selection means is connected in parallel to the radio input selection switch among the plurality of input selection switches. and switching means for switching the switch circuit when a mute signal is output from the tuning circuit, so that the input signal from the radio receiver is output from the input selection means with priority. Features: Audio input selection device.