JPH0685535U - FM radio receiver - Google Patents

Abstract

(57) [Summary] [Object] To automatically switch the frequency of an FM radio receiver when outputting the sound of an externally connected device connected externally from the speaker of the FM radio receiver. [Structure] An antenna input unit 11, a tuner unit 12, and
CPU 13, audio output unit 14, speaker 15, R
In the FM radio receiver including the OM 16 and the RAM 17, when the external connection device 30 is powered on, CP
U13 stores the value of the reception frequency set in the tuner unit 12 in the RAM 17, reads the value of the frequency stored in the ROM 16 and demodulates the frequency value, and outputs the sound of the externally connected device 30 from the speaker 15. When the power of the external device 30 is turned off, the CP is output.
U13 is a RAM just before turning on the power of the externally connected device 30.
The value of the frequency stored in 17 is read out, demodulated at that frequency, and the audio of the FM radio broadcast is output from the speaker 15.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an FM radio receiver in which the reception frequency is automatically switched.

[0002]

[Prior art]

 Most of recent TV broadcasts transmit audio in stereo, but there are still few television receivers that can output audio in stereo. Also, many compact disc (CD) and cassette tape recorders have only earphones. Therefore, conventionally, a method of outputting the sound of a TV, a CD or the like using a speaker of an FM radio receiver has been used.

FIG. 3 is a configuration diagram of a conventional FM radio receiver capable of outputting sound of a television or a CD from a speaker of the FM radio receiver. In FIG. 3, 30 is an externally connected device that outputs an audio signal, such as a television or a CD. The external connection device 30 outputs a switching signal L3 indicating whether or not the power is turned on, and an audio signal L2. The audio signal L2 is sent through two signal lines for stereo output and one signal line for monaural output. Reference numeral 20 is an FM modulator, which comprises an FM modulation circuit section 21 for modulating the audio signal L2 into an FM signal, and an output switch section 22 for switching the switch depending on the state of the switching signal L3 from the externally connected device 30. In addition, as a modulation frequency in the FM modulation circuit unit 21, a frequency not used in FM radio broadcasting is used in order to prevent interference. Reference numeral 10 denotes an FM radio receiver, which has an antenna input unit 11 for inputting an FM modulated signal, a tuner unit 12 for selecting and demodulating a specific frequency, a CPU 13 for controlling the selection of the frequency, and a demodulating unit. The audio output unit 14 that amplifies a signal and the speaker 15 that outputs the amplified signal as a sound.

In the conventional FM radio receiver as shown in FIG. 3, when the power of the external connection device 30 is turned on, the switching signal L3 from the external connection device 30 is in the ON state, and therefore the FM modulator 20. The output switch unit 22 outputs a signal obtained by FM-modulating the voice signal L2 from the externally connected device 30 by the FM modulation circuit unit 21. Further, in the FM radio receiver 10, the operator sets the frequency of the tuner section 12 to a specific value in advance, and thereby demodulates the frequency. The value of the frequency is set to the same value as the frequency FM-modulated by the FM modulator 20. As a result, the speaker 15 of the FM radio receiver 10 outputs the sound of the externally connected device 30.

When the power of the externally connected device 30 is not turned on, the switching signal L3 is in the off state, and therefore the output switch unit 22 outputs the FM radio signal from the radio antenna 40 as it is. Therefore, in the FM radio receiver 10, the operator sets the frequency of the tuner unit 12 to an arbitrary frequency of the FM radio broadcast in advance, so that the sound of the FM radio broadcast is output from the speaker 15 of the FM radio receiver. To be done.

[0006]

[Problems to be solved by the device]

 In the conventional FM radio receiver as shown in FIG. 3, when the sound of the external connection device 30 is to be output from the speaker 15 of the FM radio receiver 10, the operator must set the tuner unit 12 to a specific frequency in advance. In addition, when switching to reception of FM radio broadcasting in that state, the operator must reset the tuner unit 12 to the frequency of FM radio broadcasting.

Therefore, when the FM radio receiver 10 as in the conventional example is used for a vehicle, if the power of the external connection device 30 is turned on / off during operation, frequency tuning must be performed each time. It is troublesome.

An object of the present invention is to provide an FM radio receiver that automatically switches the reception frequency of the FM radio receiver when the sound of the externally connected device is output from the speaker of the FM radio receiver. It is in.

[0009]

[Means for Solving the Problems]

 The present invention will be described with reference to FIG. 1 showing an embodiment. The invention according to claim 1 is an FM signal receiving means 11 for receiving an FM modulated signal, and an FM signal for selecting and demodulating an FM signal. A demodulation means 12 and a voice output means 14 for amplifying the output of the FM signal demodulation means 12 are provided, and the FM signal demodulation means 12 demodulates the modulated signal obtained by modulating the voice of the externally connected device 30 to a specific frequency. It is applied to an FM radio receiver 10A capable of outputting, and is provided with control means 13 for switching the frequency of the FM signal demodulation means 12 to the specific frequency by turning on / off the power supply of the externally connected device 30. The purpose is achieved. According to a second aspect of the invention, in the FM radio receiver 10A according to the first aspect, the FM signal demodulation is performed when the power of the first storage means 16 in which the value of the specific frequency is stored in advance and the external connection device 30 is turned on. The second storage means 17 for storing the frequency value selected by the means 12 is provided, and the control means 13 appropriately switches the demodulation frequency of the FM signal demodulation means 12 to achieve the above object. To be achieved.

[0010]

[Action]

 In the invention according to claim 1, when the power of the external connection device 30 connected to the outside of the FM radio receiver 10A is turned on, the FM signal receiving means 11 causes the external connection device 30 modulated at a specific frequency. The FM signal demodulating means 12 switches the demodulation frequency to a specific frequency, demodulates the audio signal of the external connection device 30 received by the FM signal receiving means 11, and outputs it.

In the invention according to claim 2, when the power of the externally connected device 30 is turned on, the control means 13 stores the value of the frequency selected by the FM signal demodulation means 12 in the second storage means 17. The frequency of the specific frequency stored in the first storage means 16 is read out and the read out frequency is sent to the FM signal demodulation means 12 for demodulation. When the power of the connection device 30 is turned off, the frequency stored in the second storage means 17 is sent to the FM signal demodulation means 12 for demodulation.

It should be noted that, in the section of means and action for solving the above problems for explaining the configuration of the present invention, the drawings of the embodiments are used for the sake of easy understanding of the present invention. It is not limited to the example.

[0013]

【Example】

 FIG. 1 is a block diagram of an embodiment of an FM radio receiver according to the present invention. The parts common to the configuration of the conventional example shown in FIG. An FM radio receiver 10A includes an antenna input unit 11 for inputting an FM modulated signal, a tuner unit 12 for selecting and demodulating a predetermined frequency, a CPU 13 for controlling the selection of the frequency, and a demodulating unit. The audio output unit 14 for amplifying the generated signal, the speaker 15 for outputting the amplified signal as sound, the ROM 16 for storing the value of the modulation frequency in the FM modulation circuit unit 21 of the FM modulator 20, and the externally connected device. The RAM 17 stores the frequency value of the FM radio broadcast received immediately before turning on the power of 30. L1 is an automatic switching signal, which indicates whether or not the power of the externally connected device 30 is turned on, and when the power is turned on, it is turned on. Further, this signal is input to the FM radio receiver 10A and the FM modulator 20.

The operation of the embodiment will be described with reference to FIG. When the power supply of the externally connected device 30 is turned on, the automatic switching signal L1 from the externally connected device 30 is in the ON state, so that the output switch section 22 of the FM modulator 2 outputs the audio signal from the externally connected device 30. The L2 is FM-modulated by the FM modulation circuit section 21 and output. Further, the CPU 13 of the FM radio receiver 10A reads out the value of the frequency stored in the ROM 16, that is, the value of the same frequency as the frequency modulated by the FM modulation circuit unit 21, and the tuner unit 12 reads this value. Send out. The tuner section 12 demodulates at this frequency. As a result, even if the operator does not set the modulation frequency in the tuner section 12 of the FM radio receiver 10A, the sound of the external connection device 30 is output from the speaker 15.

On the other hand, when the power of the externally connected device 30 is turned off, the automatic switching signal L1 from the externally connected device 30 is turned off. Therefore, the output switch section 22 of the FM modulator 20 causes the FM radio from the radio antenna 40 to operate. The modulated signal of is output as it is. Further, the CPU 13 of the FM radio receiver 10A reads the frequency value stored in the RAM 17 and sends this value to the tuner unit 12. The tuner section 12 demodulates at this frequency. As a result, even if the operator does not set the frequency of the FM radio receiver 10A, the FM radio broadcast sound of the frequency received immediately before the power of the external connection device 30 is turned on is output from the speaker 15.

FIG. 2 is a flowchart showing the operation of the CPU 13. In step S1, it is detected whether or not the automatic switching signal L1 has changed from the off state to the on state, that is, whether or not the power source of the externally connected device 30 has been turned on. When the automatic switching signal L1 is turned on, the process proceeds to step S2, the frequency value set in the tuner unit 12 is stored in the RAM 17, and the process proceeds to step S3. In step S3, the frequency value stored in the ROM 16 is read, then in step S4, the frequency is set in the tuner unit 12, and the process returns to step S1.

On the other hand, if it is not detected in step S2 that the automatic switching signal L1 is changed from the off state to the on state, the process proceeds to step S5, in which the automatic switching signal L1 is changed from the on state to the off state. It is detected whether or not the power of the externally connected device 30 is turned off. If the power is turned off, the process proceeds to step S6, the frequency value stored in the RAM 17 is read, and the process proceeds to step S4. If it is not detected in step S5 that the automatic switching signal L1 has changed from the off state to the on state, the process proceeds to step S7, the frequency set in the tuner section 12 is selected, and the process proceeds to step S4.

In the above embodiment, the frequency of the FM radio receiver 10A is switched by turning on / off the power of the external connection device 30 while the power of the FM radio receiver 10A is turned on in advance. Although an example has been shown, the power supply of the FM radio receiver 10A may be controlled in addition to this. That is, when the power of the externally connected device 30 is turned on and the automatic switching signal L1 is turned on, even if the power of the FM radio receiver 10A is not turned on, the frequency is switched after the power is automatically turned on. May be performed.

In the embodiment configured as described above, the antenna input section 11 serves as an FM signal receiving means, the tuner section 12 serves as an FM signal demodulating means, the speaker 14 serves as an audio output means, and the CPU 13 serves as a control means. , ROM 16 corresponds to the first storage means, and RAM 17 corresponds to the second storage means.

[0020]

[Effect of device]

 As described in detail above, according to the present invention, when the sound of an externally connected device such as a television or a CD connected to the outside is output from the FM radio receiver, the power of the externally connected device is turned on / off. By doing so, the frequency of the FM radio receiver is automatically switched. Therefore, even if the operator does not set the frequency again, the sound of the externally connected device is turned on when the power of the externally connected device is turned on, and the power of the externally connected device is turned on. If not, the FM radio broadcast audio can be output from the FM radio receiver. According to the second aspect of the present invention, the FM radio receiver is internally provided with a ROM for storing a frequency value used for outputting the sound of the externally connected device, and immediately before the power of the externally connected device is turned on. If a RAM that stores the frequency value of the FM radio broadcast that was being received is installed in the device, and the power of the externally connected device is turned on while the FM radio broadcast is being received, the value of the frequency that has been received so far will be displayed. Is stored in the RAM, the frequency stored in the ROM is read, and demodulation is performed at this frequency. Therefore, the voice of the externally connected device is automatically output without the operator having to reset the frequency. It can be output from the FM radio receiver. On the other hand, when the power of the externally connected device is turned off in that state, the frequency stored in the RAM is read and the demodulation is performed at this frequency, so the operator can set the frequency automatically without resetting it. Therefore, the sound of FM radio broadcasting can be output from the FM radio receiver. Therefore, when such an FM radio receiver is used for in-vehicle use, it is not necessary to change the frequency of the FM radio receiver even if the power of the externally connected device is turned on / off during operation, and it is possible to switch the frequency. The operation is simplified.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of an FM radio receiver according to the present invention.

FIG. 2 is a flowchart showing the operation of the CPU of this embodiment.

FIG. 3 is a configuration diagram of a conventional FM radio receiver.

[Explanation of symbols]

 10A FM radio receiver 11 Antenna input unit 12 Tuner unit 13 CPU 14 Audio output unit 15 Speaker 16 ROM 17 RAM 20 FM modulator 30 External connection device 40 Radio antenna

Claims (2)

[Scope of utility model registration request] 1. An FM signal receiving means for receiving an FM modulated signal, an FM signal demodulating means for selecting and demodulating an FM signal, and an audio output means for amplifying an output of the FM signal demodulating means, An FM radio receiver capable of demodulating a modulated signal obtained by modulating the sound of an externally connected device to a specific frequency by the FM signal demodulating means and outputting the modulated signal, by turning on / off a power source of the externally connected device. An FM radio receiver having a control means for switching the frequency of the demodulation means to the specific frequency. 2. The FM radio receiver according to claim 1, wherein the FM signal demodulating means tunes to the first storage means in which the value of the specific frequency is stored in advance, and the FM signal demodulating means when the power of the externally connected device is turned on. Second storage means for storing the value of the frequency that has been set, and the control means, when the power of the externally connected device is turned on, the value of the frequency selected by the FM signal demodulation means. Is stored in the second storage means, the value of the specific frequency stored in the first storage means is read, and the read frequency is sent to the FM signal demodulation means for demodulation. An FM radio receiver characterized in that when the power of the externally connected device is turned off, the frequency stored in the second storage means is sent to the FM signal demodulation means for demodulation.