JPH0322095B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a broadcast receiver that allows channel selection using a broadcast station name code. In conventional broadcast receivers, tuning was performed using a tuning knob. In other words, if you want to receive broadcasts from station A, check the frequency of station A and turn the tuning knob. or,
Turn the tuning knob and listen to each station, then search for station A and receive it. The stations that broadcast the program A-station have different frequencies depending on the region.
Therefore, when the user of the broadcast receiver wants to receive station A at a place other than the usual place of use, for example, while traveling, the frequency is different from the place of normal use, so he cannot easily tune in and receive it. In addition, if you are receiving A station while using a car or train, it may be difficult to receive A station as you move.
If you leave the station's service area, you will have to find and tune in to another station that is broadcasting the same program. Depending on the topography of the location you are moving to and the frequency band you are receiving, it is extremely inconvenient to switch stations frequently. There are TV broadcast receivers on the market that allow you to select channels with a push button, but the channels vary depending on the region, so you have to set the channels after purchasing, which can be inconvenient when moving. be. The present invention eliminates this drawback, and its purpose is to automatically select a broadcasting station by inputting the station name. At present, research and practical application of teletext and multiplex broadcasting are actively being conducted. The invention is related. Hereinafter, the present invention will be explained in detail based on Examples. FIG. 1 is a block diagram of the present invention. Broadcast radio waves received by antenna 1 are tuned, amplified, and demodulated by tuning amplification and demodulation section 2. As a tuning element for tuning, a variable capacitance diode or the like is used in order to tune by voltage input as described later. The station name signal separation unit 3 separates the multiplexed modulated station name signal by time-division or frequency separation of the video signal, audio signal, etc., outputs the station name signal from 3-1, and outputs the station name signal from 3-2. outputs video signals, audio signals, etc. 4 is the station name signal decoding unit, which converts the signal that has been converted so that it can be easily transmitted via broadcast radio waves so that it can be easily processed inside the broadcast receiver (for example, converts a signal sent serially to parallel) . 5
is a station selection input section, which generates a station name signal when a station name is input. The coincidence detection circuit 6 inputs the station name signal demodulated from the received radio wave 4 and the station name signal input by the receiver, detects coincidence or mismatch, and returns 0 when there is a match, and 0 when there is no match. Outputs 1 at the time. 7 is a tuning voltage generator. 2-1 is AGC output, 4-1 is clock output,
8 is an inverter, 9 is an OR gate, and 10 is an AND gate. 2-1 is the AGC output, which outputs 0 when detuned and 1 when tuned. 4-1 is a clock output which becomes 1 when the output of the station name decoder 4 is valid, in other words, the output of the coincidence detection circuit 6 is valid. Table 1 shows the relationship between the above inputs and outputs.

[Table] As shown in Table 1, when detuning occurs, the sweep is stopped, the clock output is enabled, and when the station matches the station input to the tuning input section 5, the tuning voltage is fixed, and when the station does not match, the sweep starts again. do. Even if the input station is received, if the reception condition worsens, the AGC will output when the station is out of tune.
Start sweeping. FIG. 2 is a time chart showing the operation of the tuning voltage generating section, where A is the coincidence detection circuit output and B is the tuning voltage generating section output. As shown in FIG. 2, the output of the tuning voltage generator continuously increases in voltage when the output of the coincidence detection circuit is 1. Further, when the output of the coincidence detection circuit changes from 1 to 0, it is fixed to the output voltage of the tuning voltage generating section at that time. Furthermore, when the output of the coincidence detection circuit changes from 0 to 1, the output voltage of the tuning voltage generator starts to rise again. However, when the output voltage reaches V, it rapidly drops to 0 and starts rising again. V is a reverse bias applied to the variable capacitance diode of the tuning amplification demodulation section 2, so it ranges from several volts to 20 to 30 volts. The details of the operation have been described above, and will be explained in conjunction with actual usage conditions. When the broadcast receiver is turned on, first input the name of the broadcasting station into the channel selection input section 5.
At that time, if the broadcast station is not being received, the output of the coincidence detection circuit 6 becomes 1, and the tuning voltage generator 7 starts increasing the voltage. As the voltage increases, the capacitance of the variable capacitance diode of the tuning amplification and demodulation section 2 decreases, and the reception frequency increases. When the reception frequency changes and a certain broadcast is received, a station name signal is output from the station name signal decoder 4. In the coincidence detection circuit 6, even if the station name signal is output from 4,
When the output of 5 and the output of 6 do not match, the output of 6 remains 1,
The output of the coincidence detection circuit becomes 0 only when the same station name signal as the desired broadcasting station is output from 4.
The output of the tuning voltage generator is fixed. After that, the receiving state is maintained until another station name is entered in 5 or the receiving station becomes unable to receive. As described above, according to the present invention, when tuning a broadcast receiver, there is no need to take the trouble of turning the tuning knob to search for a broadcast station, and the music is automatically selected by inputting the name of the broadcast station. It's convenient. In addition, in the case of conventional automatic receivers, if the sweep time of the tuning voltage generator is short compared to the length of the station name signal, there is a problem that the tune will be detuned before the station name signal is completely received. However, in the present invention, the tuning voltage is fixed as long as the station name signal is valid and matches the tuning input signal after tuning, so there is no detuning as described above and reliable reception is possible. can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the present invention. FIG. 2 is a time chart of the tuning voltage generator. DESCRIPTION OF SYMBOLS 1... Antenna, 2... Tuning amplification demodulation section, 3... Station name signal separation section, 4... Station name signal decoding section, 5... Tuning selection input section, 6... Coincidence detection circuit, 7... Tuning voltage generation section, 8
...Inverter, 9...OR gate, 10...AND gate, 2-1...AGC output, 3-1...station name signal, 3
-2...Video signal, audio signal, 4-1...Clock output.

Claims (1)

[Claims] 1. An antenna that receives broadcast waves with station names multiplexed, and a tuned amplifier that selects, amplifies, and demodulates the broadcast waves from the antenna, and outputs an AGC signal in a detuned or tuned state. a demodulator; a station name signal decoder that separates the station name signal from the tuned amplification demodulator when in a tuned state, and outputs a valid signal when the station name signal is valid and an invalid signal clock signal when it is invalid; optional; A matching input section that selects the name of a broadcasting station, and a matching section that compares the conversion signal from the station name signal decoding section and the input channel selection signal from the channel selection input section, and outputs a match detection signal indicating a match or mismatch. a detection circuit; gate means for obtaining the product of the clock signal and the detection signal; a tuning voltage signal outputted from the output signal from the gate means and the AGC signal and supplied to the tuning amplification demodulation section; the tuning voltage signal is A broadcast receiver characterized in that it is fixed.