Multi-band voltage variable capacitance tuner having automatic and manual tuning operations

A tuning apparatus comprising:

• a dial plate marked with broadcast frequencies thereon;
• a substrate having a resistive layer thereon, said resistive layer having varying resistance valves distributed therealong which correspond to said broadcast frequencies on said dial plate, said resistive layer also being supplied with a DC voltage at opposite ends thereof;
• a plurality of marker means slidably disposed with respect to said dial plate to indicate a predetermined broadcast frequency, each having a first electrically conductive slide element for slidably contacting said resistive layer to detect one of a plurality of predetermined DC voltages in response to the location of said marker means;
• mounting means slidably disposed in parallel with said dial plate, including a display member extending toward said dial plate to indicate a manually selected broadcast frequency, and a second electrically conductive slide element for slidably contacting said resistive layer to detect a predetermined DC voltage in response to the location of said mounting means;
• and
• switching means supplied with at least one of said predetermined DC voltages from said first and second slide elements and selectively supplying one of said predetermined DC voltages to a turning circuit as a tuning control voltage.

A tuning apparatus comprising:

• a dial plate marked with broadcast frequencies for first and second frequency bands thereon;
• first and second substrates having first and second resistive layers thereon, respectively, said resistive layers having varying resistance values distributed therealong which correspond to said broadcast frequencies on said dial plate, each said resistive layer also being supplied with a DC voltage at opposite ends thereof;
• a first set of marker means associated with the first broadcast frequency band, said first set being slidably disposed with respect to said dial plate to indicate a predetermined broadcast frequency in the first frequency band and each said marker means of said first set having a first electrically conductive slide element for slidably contacting said first resistive layer to detect one of a plurality of predetermined DC voltages in response to the location of said marker means;
• a second set of marker means associated with the second frequency band, said second set being slidably disposed with respect to said dial plate to indicate a predetermined broadcast frequency in the second frequency band and each said marker means of said second set having a second electrically conductive slide element for slidably contacting said second resistive layer to detect one of a plurality of predetermined DC voltage in response to the location of said marker means;
• mounting means slidably disposed in parallel with said dial plate, including a display member extending therefrom toward said dial plate to indicate a manually selected broadcast frequency, and having third and fourth electrically conductive slide elements for slidably contacting said first and second resistive layers, respectively, to detect a predetermined DC voltage in response to the location of said mounting means;
• and
• switching means supplied with at least one of said predetermined DC voltages from said first through fourth slide elements and selectively supplying one of said predetermined DC voltages to a tuning circuit as a tuning control voltage.