Pioneer Electronic Corporation

Hiroyuki Kimura

Yoshiro Sugai

Mitsuo Syoji

An automatic station searching device for a radio receiver in which the order in which the station data is stored in a memory device can be altered so that the user can easily selected between storage in the order of signal strength or storage in the order of frequency. Frequency and signal strength data for received stations are stored in order of signal strength during the sweeping operation. At the end of the sweeping operation, the data are rearranged in order of frequency if a memory bit has been set to so indicate.

Automatic station searcher

A power source for an electronically tuned tuner in which a horizontal deflection circuit supplies high voltage power to a fly-back transformer, supplying power to the tuner, when a television signal is received but otherwise a battery source is switched into supplying the tuner. The change-over circuit may be realized by a relay, by transistors or by diodes.

Power source for electronic tuning tuner

A multivoice demodulator circuit in which a sub-signal is separated from the main signal. The sub-signal may have different content and characteristic dependent upon the reception mode of the original signal. The sub-signal is given different frequency characteristics dependent upon the reception mode.

Variable bandwidth multivoice demodulating circuit

A signal receiving system for a TV receiver incorporates at least two independent front end circuits for frequency-converting antenna signals to a lower frequency, with the output signals from these front end circuits being utilized separately to derive the video and audio signal components of the TV signal. Independent control of AGC applied to the audio and video signal components respectively can thereby be implemented, or, in the case of diversity reception using two or more antennas, the optimum antenna for reception of the video and audio signal components respectively can be selected in a mutually independent manner, to thereby attain substantially improved diversity reception, e.g. for a TV installation in a moving vehicle.

Signal reception system for television receiver

In a sound multiplex television tuner, when the input field strength becomes smaller than a certain value, a level control means continuously attenuates the sub signal demodulation output with the aid of the field strength detection signal which a field strength detector circuit provides according to the input field strength. The characteristic of response to input field strength of the level control means is switched, according to a given sound multiplex mode, so that its operation becomes most suitable for the sound multiplex mode, thereby to suppress the noise without causing the television viewer to feel a sense of incongruity in the perceived sound.

Audio multiplex television tuner

A multiplex sound receiver in which a detection signal is extracted from a broadcast to indicate whether the broadcast is monaural, stereo, or multi-lingual. The detection signal is used for controlling the separating of the channels. According to the invention, the detection signal is processed in accordance with the strength of the broadcast or the noise level. For instance, the detection signal is integrated over a period that is increased when the field strength decreases.

Sound multiplex receiver

A noise eliminating circuit including a subsignal modulator circuit, a matrix circuit, and sample-and-hold circuits, for reducing signal distortion as well as preventing the in-circuit generation of noise. The sample-and-hold circuits are disposed in the signal paths of a main signal and the demodulated subsignal and are operated by a signal synchronous with a noise component. The holding times of the two sample-and-hold circuits may be made different from one another.

Growing community of inventors

Saitama, Japan

Hiroyuki Kimura