Musical instrument tuner with incremental scale shift

Claim 2

Scale shifting circuitry for providing a plurality of frequencies having a predetermined frequency relationship and for shifting said plurality of frequencies by predetermined increments, and comprising in combination: first oscillator means for providing a fixed frequency signal which is substantially higher than said plurality of frequencies; a phase locked loop coupled to receive an output signal of the first oscillator means and including a second oscillator means adapted to provide an output signal at a frequency substantially higher than the output signal from the first oscillator means; first programmed divider means coupled to receive the output signal from the second oscillator means of the phase locked loop, to divide said output signal by ones of a first plurality of numbers related to said predetermined incremental frequency shifts, and to couple the divided signal to the phase detector of the phase locked loop; chromatically programmed divider means coupled to receive the output signal from the second oscillator means, and to divide said output signal by ones of a second plurality of numbers related to said plurality of frequencies; and output means coupled to the chromatically programmed divider means.

Claim 3

Scale shifting circuitry in accordance with claim 1 wherein the first oscillator means comprises a crystal oscillator and a fixed divider.

Claim 4

Scale shifting circuitry in accordance with claim 1 vider means comprises a med dibinary counter, a diode network, and increment selector means for coupling portions of the diode network to the binary counter.

Claim 5

Scale shifting circuitry in accordance with claim 1 wherein the chromatically programmed divider means comprises a second binary counter, a second diode network, and tone selector means for coupling portions of the second network to the second binary counter.

Claim 6

Scale shifting circuitry in accordance with claim 1 and further including at least one divide-by-two circuit coupled to the output of the chromatically programmed divider.

Claim 7

A tuning device for the visual comparison of two audio frequencies, having a video display screen and a bar pattern generator, and comprising in combination: a video control circuit coupled to said screen; first oscillator means for providing a reference frequency; phase locked loop means coupled to the first oscillator means and including a second oscillator means adapted to provide a frequency substantially higher than the reference frequency; first divider means coupled to the phase locked loop means for receiving the phase locked loop output frequency, dividing said frequency by ones of a first set of predetermined divisor numbers and coupling said divided frequency back to the phase comparator of the phase locked loop means; second divider means coupled to the phase locked loop means for receiving the phase locked loop output frequency and dividing said output frequency by ones of a second set of predetermined divisor numbers, the output of the second divider means being coupled to the video control circuit for producing a fixed reference bar pattern on one portion of said video display screen; input means for receiving an external signal and having an output coupled to the video control circuit for producing a second bar pattern on a second portion of the cathode ray tube screen.

Claim 8

A tuning device for the visual comparison of two audio frequencies, having a video display screen and a bar pattern generator, and comprising in combination: a video control circuit coupled to said screen; first oscillator means for providing a reference frequency; phase locked loop means coupled to the first oscillator means and including a second oscillator means adapted to provide a frequency substantially higher than the reference frequency; first divider means coupled to the phase locked loop means for receiving the phase locked loop output frequency, dividing said frequency by ones of a first set of predetermined divisor numbers and coupling said divided frequency back to the phase comparator of the phase locked loop means; second divider means coupled to the phase locked loop means for receiving the phase locked loop output frequency and dividing said output frequency by ones of a second set of predetermined divisor numbers, the output of the second divider means being coupled to the video control circuit for producing a fixed reference bar pattern on one portion of said video display screen; input means for receiving an external signal and having an output coupled to the video control circuit for producing a second bar pattern on a second portion of the cathode ray tube screen.

Claim 9

A tuning device in accordance with claim 9 wherein the input means comprises a microphone and an audio amplifier coupled to the microphone output.

Claim 10

A tuning device in accordance with claim 7 wherein the input means further includes at least one divide-by-two circuit coupled to the amplifier output, and selector means coupled to enable selector means coupled to enable selection of ones of the amplifier output signal and the divide-by-two circuits.