Sharp Kabushiki Kaisha Corporation

Nobuo Minoura

Takao Abumi

Isao Matsumura

Kazuhiro Nakai

Yasukazu Yoshinaga

An automatic tuning scheme for use in TV receivers includes a start/stop circuit which creates a search start signal and a search stop signal upon the receipt of a search start instruction and a detected incoming signal, respectively, a tuning voltage generator which generates a gradually varying tuning voltage under control of the search start signal and search stop signal, and a memory circuit for storing the tuning voltage from the generator when desired. The tuning voltage stored in the memory circuit is supplied to a tuner including a well known voltage-sensitive capacitance diode.

Automatic pre-programming system for TV receivers

A television signal determination circuit is associated with an automatic tuning system, which automatically tunes a television set to local channels, in order to determine whether received signals are desired television signals. The television signal determination circuit comprises a first counter means for counting received synchronizing signals for a predetermined period of time, a second counter means for counting reference clock signals for the predetermined period of time, and a determination means for determining whether the synchronizing signals are received by a predetermined number within the predetermined period of time by comparing output signals from the first and second counter means.

Television signal determination in an automatic tuning system

In a power supply circuit useful for a horizontal deflection circuit in a television receiver, there is provided a voltage-controlled semiconductor element, for example, such as silicon controlled rectifier, in order to stabilize effectively the output power voltage. The silicon controlled rectifier is switched between its OFF and ON states in response to two kinds of pulses: flyback pulses occurring within the television receiver and newly produced control pulses having relative phases with respect to the phase of the flyback pulses which relative phases differ depending upon variations in the input power voltage. Current flow through the silicon controlled rectifier charges a capacitor connected thereto which in turn provides the stabilized output voltage to the horizontal deflection circuit.

Growing community of inventors

Ohtawara, Japan

Nobuo Minoura