JPS625491B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic channel selection device mainly used in car radios.

A radio station that broadcasts over a wide area, e.g.
NHK broadcasting stations have different frequencies depending on the region. Therefore, if a car moves from region to region while still receiving stations on one frequency, the electric field strength of the received signal will decrease and the reception quality will deteriorate. It is necessary to switch to a station with a frequency of
Conventionally, the above-mentioned switching operation was performed manually, but there was a drawback that such manual operation while driving was accompanied by danger.

This invention was made to solve the above-mentioned conventional drawbacks. For example, if the frequencies of multiple stations broadcasting the same content are stored in advance, the frequencies of multiple stations broadcasting the same content can be constantly swept. It is an object of the present invention to provide an automatic channel selection device that maintains good reception quality by detecting electric field strength and automatically selecting and receiving a station with the highest electric field strength.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a tuning circuit having a detection circuit, which receives a tuning signal from a tuning signal generator 3 of a control circuit 2, selects a station corresponding to this tuning, and selects a station corresponding to the tuning signal.
A received signal R as shown in the figure is sent to the speaker 5 via the low frequency amplifier 4 of FIG. 1 and reproduced.

The received signal of the station selected by the selection circuit 1 is sent to the detection circuit 7, and the field strength and frequency of the received signal are detected by the field strength detector 11 and frequency detector 12, respectively. The electric field strength and frequency are then converted into corresponding code signals by the station detection signal generator 13. That is, a station detection signal consisting of a code signal representing the electric field strength and frequency of the received signal, that is, the station, is output from the detection circuit 7 and stored in the storage circuit 8.

Reference numeral 9 denotes a normally closed muting switch inserted on the input side of the low frequency amplifier 4, and a control section 10 such as a microcomputer in the control circuit 2.
It operates upon receiving a muting instruction signal at a constant cycle from , and as shown in FIG. 2, the reproduction of the received signal R of the selected station is interrupted for only an extremely short predetermined time a. On the other hand, for example, the control unit 1 in FIG.
The information is stored in the memory circuit 8 in advance by operating a known push button at 0. When the stations other than the one currently being played out of the plurality of stations are set as the predetermined stations, the control section 10 controls the playback of the music as shown in steps a to d of the flowchart of FIG. When the tuning switch 9 is opened and the reproduction is interrupted, that is, during the predetermined time a, a station display signal representing the frequency of the predetermined station is received from the storage circuit 8, and the station display signal representing the frequency of the predetermined station is received from the storage circuit 8. The station display signal is sent to the channel selection signal generator 3, and the channel selection signals corresponding to the predetermined stations are sequentially outputted to the channel selection circuit 1, so that the predetermined stations are received. Here, one station is received every predetermined time a, and the predetermined station to be received is sequentially changed every predetermined time a. Therefore, since the predetermined time a is only short enough to receive one station, it is possible to minimize interruptions in the auditory sense due to interruptions in playback.

In this manner, while playback is interrupted, the predetermined stations are sequentially received by the channel selection circuit 1, and via the detection circuit 7, the electric field strength and the station detection signal representing the station are stored in the storage circuit 8. The electric field strength of one station currently being reproduced and a station detection signal representing the station are output from the detection circuit 7 to the storage circuit 8 during reproduction.

In addition, as shown in steps e and f of the flowchart in FIG. A detection signal is selected and received, and a channel selection signal corresponding to the one station represented by this station detection signal is outputted from the channel selection signal generator 3 to the channel selection circuit 1. A station with high intensity is received and reproduced by the speaker 5.

The tuning signal from the tuning signal generator 3 is, for example, a voltage signal, and is sent to the tuning circuit 1 by the action of the control section 10 when the muting switch 9 is in the closed state, that is, when reproduction is being performed. One voltage signal is sent to select one station, and when the muting switch 9 is in the open state, that is, when muting is applied and playback is interrupted, the voltage signal is switched to select another station. It is designed to sweep. Note that the channel selection signal from the channel selection signal generator 3 is also input to the storage circuit 8 as a drive voltage.

As explained above, according to the present invention, for example, among multiple stations broadcasting the same content, the station with the highest electric field strength is automatically selected, so that good reception quality is always maintained. With,
Conventional manual operations while driving are no longer necessary,
Eliminates danger while driving. Furthermore, since stations are received one by one every predetermined time period during which muting is continued, the predetermined time period is only short enough to receive one station, thereby minimizing interruptions in the auditory sense due to interruptions in playback. can. Further, since only one channel selection circuit is required as in the conventional case, it is possible to avoid increasing the size and complexity of the device.

[Brief explanation of the drawing]

FIG. 1 is a schematic system diagram showing an embodiment of the present invention, and FIG. 2 is a signal waveform diagram showing an example of a received signal. FIG. 3 is a flowchart illustrating the functions of the control section 10. DESCRIPTION OF SYMBOLS 1... Tuning circuit, 2... Control circuit, 7... Detection circuit, 8... Memory circuit, 9... Muting switch, R... Received signal, a... Predetermined time.

Claims (1)

[Claims] 1. A tuning circuit that receives broadcast waves from broadcast stations, a storage circuit that stores frequency data of multiple broadcast stations in advance,
a tuning signal generation circuit that changes the reception frequency of the tuning circuit according to frequency data selected from the frequency data of the storage circuit; a muting switch that suspends reproduction of the reception signal of the tuning circuit for a predetermined period; a detection circuit for detecting a received electric field strength and a received broadcasting station from the received signal of the tuning circuit and storing a station detection signal indicating the electric field strength and the broadcasting station in the storage circuit; and for interrupting reproduction of the received signal; A muting instruction signal is sent to the mutating switch, and when the reproduction of the received signal is interrupted, one frequency data other than the currently received frequency data of the frequency data in the storage circuit is transmitted to the mutating switch. is set in the station selection signal generation circuit, and when the received signal is being reproduced, the station detection signal showing the largest electric field strength is selected from among the station detection signals in the storage circuit, and the station detection signal indicated by this station detection signal is selected. An automatic tuning device comprising: a control section that sets frequency data of a broadcasting station to the tuning signal generation circuit.