Tone signal synthesizer with touch control

A tone signal synthesizer comprising:

• touch signal generation means for generating a touch signal representing a degree of a performance;
• a loop circuit for circulating a tone signal;
• means for applying a driving waveform based on said pitch signal to said loop circuit;
• a delay circuit connected within said loop circuit, for delaying the circulating tone signal by a delay time which corresponds to the pitch of a tone signal to be synthesized;
• a variable all-pass filter connected within said loop circuit and being capable of changing the phase of the tone signal corresponding to the frequency thereof;
• factor generation means for generating a filtering amplification factor which changes with the passage of time and corresponding to said touch signal;
• and
• means for applying said filtering amplification factor to said all-pass filter to variably control the phase changes imparted to the tone signal by the filter,
• wherein said factor generation means includes means for generating a pitch envelope for controlling the filter for increasing pitch by a quantity corresponding to the touch signal simultaneously with the starting of performance manipulation and then decreasing the pitch in the form of an exponential function, said filtering amplification factor being based upon said pitch envelope, whereby both phase changes imparted to the filter and pitch changes are controlled on the basis of the pitch envelope.

A tone signal synthesizer comprising:

• touch signal generation means for generating a touch signal representing a degree of a performance;
• a loop circuit for circulating a tone signal;
• means for applying a driving waveform based on said pitch signal to said loop circuit;
• a delay circuit connected within said loop circuit, for delaying the circulating tone signal by a delay time which corresponds to the pitch of a tone signal to be synthesized;
• a variable all-pass filter connected within said loop circuit and being capable of changing the phase of the tone signal corresponding to the frequency thereof, the all-pass filter including a delay element for delaying an input signal;
• a first amplifier for amplifying the input signal with an amplification factor .alpha.;
• a first adder for adding the amplified input signal to the output of said delay element in reversed phase;
• a second amplifier for amplifying the output of said first adder with amplification factor .alpha.;
• and a second adder for adding the output of said second amplifier to the input signal in phase at the input side of said delay element, the delay time of said delay element and the amplification factor .alpha. of the first and second amplifiers being controlled on the basis of an externally applied control signal;
• a factor generation means for generating a filtering amplification factor which changes with the passage of time and corresponding to said touch signal;
• means for applying said filtering amplification factor to said all-pass filter to variably control the phase changes imparted to the tone signal by the filter;
• and
• means for receiving a signal representing pitch and a signal representing touch and for supplying to said all-pass filter a signal for controlling the amplification factor .alpha. and the delay time.

A tone signal synthesizer for an electronic musical instrument comprising:

• loop means for circulating a tone signal;
• applying means for applying a driving signal to the loop means;
• variable delay means connected within the loop means, for delaying the circulating tone signal for a delay time corresponding to a tone pitch of a tone signal to be generated;
• variable all-pass filter means connected within the loop means, for changing the phase of the circulating tone signal corresponding to the frequency thereof according to an all-pass filter characteristic, said variable all-pass filter means including a variable delay element for delaying the circulating tone signal and an amplifier for amplifying the circulating tone signal;
• touch signal generation means for generating a touch signal representing a degree of a performance;
• and
• control means for changing a delay time of said variable delay element and an amplification factor of said amplifier in response to the touch signal so as to change the all-pass filter characteristic with the passage of time.

A tone signal synthesizer for an electronic musical instrument comprising:

• loop means for circulating a tone signal;
• applying means for applying a driving signal to the loop means;
• delay means connected within the loop means, for delaying the circulating tone signal for a delay time corresponding to a tone pitch of a tone signal to be generated;
• all-pass filter means connected within the loop means, for changing the phase of the circulating tone signal corresponding to the frequency thereof according to an all-pass filter characteristic;
• touch signal generation means for generating a touch signal representing a degree of a performance;
• and
• control means for controlling the all-pass filter characteristic in response to the touch signal, wherein the all-pass filter means includes a delay and wherein the delay length changes with a lapse of time in response to the touch signal to vary the pitch of the tone being generated.