Sanyo Electric Co., Ltd.

Other

Yoshiaki Sakauchi

Kazufumi Ushijima

Yasuhiro Yamada

Kazuyoshi Tsukamoto

Yukio Saito

Hajime Suzuki

Takashi Tamura

Shigeru Wakamoto

Hisao Kanou

Kazuyoski Tsukamoto

An automatic tuning apparatus comprising a tuner having a tank circuit employing a voltage controlled variable capacitance diode as a circuit element, which diode is reverse biased with a scanning control voltage from a solid state potential memory device, which control voltage is varied under the control of a scanning voltage control circuit to scan the frequencies in the frequency band by the tuner and is set by a scan stop signal obtained from the tuner as a result of tuning of the tuner to a certain frequency, said scan stop signal being withdrawn by way of a logical product of the level detected output of the IF signal and the level detected output of the ratio detected output of the IF signal, a manual switch for starting the scanning, an automatic frequency control responsive to said level detected output of said ratio detected output for charging or discharging said potential memory device, said automatic frequency control being disabled in response to the absence of the level detected output of the IF signal, and a pseudo IF signal generating circuit responsive to turning on of the power source for providing a pseudo IF signal for a predetermined period of time, whereby the automatic frequency control is performed irrespective of a possible change in the IF signal after the power source is turned off until it is turned on again.

Automatic tuning apparatus

An apparatus for indicating a tuned frequency of a tuner of a radio or television receiver, said tuner comprising a tank circuit employing a voltage controlled variable capacitance diode as a circuit element, which diode is supplied in a reverse direction with a scanning control voltage from a solid state potential memory device, which control voltage is set as a result of tuning of said tuner, said indicating apparatus comprising a plurality of light emitting diodes arranged in a line, each illuminating the corresponding frequency indicating region out of a plurality of divided frequency indicating regions of a frequency band to be received by said receiver, said regions being arranged in succession to cover said frequency band, and a corresponding plurality of drivers responsive to said control voltage for energizing the corresponding light emitting diode for illuminating the corresponding frequency region to which said tuned frequency pertains. In a preferred embodiment of the invention, the frequency indicating regions to be covered by the adjacent light emitting diodes are adapted to be overlapped in part at the ends thereof, so that the frequency in the overlapped portion in the region is indicated by said two adjacent light emitting diodes.

Indicating device for tuning apparatus

An automatic tuning apparatus comprising a tuner having a tank circuit employing a voltage controlled variable capacitance diode as a circuit element, which diode is supplied in the reverse direction with a scanning control voltage from a solid state potential memory device, which control voltage is varied under the control of a scanning voltage control circuit to scan the frequencies in the frequency band by the tuner and is set by a scan stop signal obtained from the tuner as a result of tuning of the tuner to a certain frequency, and a pair of manual switches for upward and downward scanning, a first flip-flop to be reset by the closing of either manual switch and to be set by the scan stop signal, a second flip-flop to be set and reset by the closing of the downward and upward scanning switches, respectively, a third flip-flop to be set and reset by the closing of both manual switches and caused to be reversed in the storing state thereof when the scanning voltage reaches the maximum or minimum value thereof, the said scanning voltage control circuit being controlled by the logical combination of the storing state of these flip-flops such that the frequency is scanned gradually in the direction as selected by the manual switch but rapidly in the direction not selected by the switch.

An automatic tuning apparatus, such as an automatic channel selector as incorporated in a television receiver, comprising a tuner using a voltage controlled variable capacitance diode such that the variable capacitance thereof constitutes a portion of a tuning circuit of the tuner for changing the tuning frequency, and a solid state electrochemical potential memory devices an output voltage of which is clamped as selected by selective manual operation, the resultant voltage being applied to the capacitance diode in a reverse direction, which memory device is controlled so as to be charged or discharged in response to selective manual operation until an increased or decreased terminal voltage thereof decreases or increases the capacitance across the diode and thus increases or decreases the tuning frequency of the tuner and a particular frequency is tuned. An intermediate frequency output, obtained as a result of tuning, is used to disable the abovementioned charging or discharging operation of the potential memory device.

An automatic tuning apparatus, such as an automatic channel selector as incorporated in a television receiver, comprising a tuner using a voltage controlled variable capacitance diode such that the variable capacitance thereof constitutes a portion of a tuning circuit of the tuner for changing the tuning frequency thereof, and a solid state electrochemical potential memory device, an output voltage of which is applied to the capacitance diode in a reverse direction, which memory device is controlled so as to be charged or discharged in response to selective manual operation until an increased or decreased terminal voltage thereof decreases or increases, respectively the capacitance across the diode and thus increases or decreases, respectively the tuning frequency of the tuner and a particular frequency is tuned. An intermediate frequency output, obtained as a result of tuning, is used to disable the abovementioned charging or discharging operation of the potential memory device.

Growing community of inventors

Tenri, Japan

Yoshiaki Sakauchi