Delayed vibrato arrangement for an electronic musical instrument

Claim 2

A vibrato signal generating arrangement for an electronic musical instrument comprising: envelope signal generating means for generating an envelope signal which changes from a first potential level to a second potential level in response to and at the instant of key depression, and thereafter changes gradually from said second potential level to said first potential level; clipping means coupled to said envelope signal generating means and having a predetermined clipping level between said first and second potential levels for clipping off a portion of said envelope signal between said second potential level and said clipping level; and vibrato signal generating means coupled to said clipping means and driven directly by the output of said clipping means so as to be operative to produce a vibrato signal, said vibrato signal generating means being so arranged that it does not operate at a signal level of the output of said clipping means corresponding to said clipping level and produces the vibrato signal in response to a signal level of the output of said clipping means other than the signal level corresponding to said clipping level and at an amplitude in accordance with the signal level of the output of said clipping means.

Claim 3

The arrangement according to claim 1, wherein said envelope signal generating means includes means for receiving a trigger pulse which is generated in response to key depression, a series combination of a resistor and a capacitor connected across a DC voltage source, and a switching circuit connected in parallel with said capacitor and rendered conductive in response to application of said trigger pulse.

Claim 4

The arrangement according to claim 1, wherein said clipping means includes a diode.

Claim 5

A vibrato signal generating arrangement for an electronic musical instrument comprising: envelope signal generating means for generating an envelope signal which changes from a first potential level to a second potential level in response to and at the instant of key depression, and thereafter changes gradually from said second potential level to said first potential level; clipping means coupled to the output of said envelope signal generating means and having a predetermined clipping level between said first and second potential levels for clipping off a portion of said envelope signal between said second potential level and said clipping level; means coupled to the output of said clipping means for generating first and second control signals having a common level corresponding to a clipped level of the output of said clipping means and symmetrical waveforms with respect to said common level which are similar to the output of said clipping means; and vibrato signal generating means coupled to said means for generating said first and second control signals and driven directly by said first and second control signals for generating a vibrato signal with an amplitude proportional to the potential difference between said first and second control signals.

Claim 6

A vibrato signal generating arrangement for an electronic musical instrument comprising: envelope signal generating means for generating an envelope signal which changes from a first potential level to a second potential level in response to and at the instant of key depression, and thereafter changes gradually from said second potential level to said first potential level; clipping means coupled to the output of said envelope signal generating means and having a predetermined clipping level between said first and second potential levels for clipping off a portion of said envelope signal between said second potential level and said clipping level; means coupled to the output of said clipping means for generating first and second control signals having a common level corresponding to a clipped level of the output of said clipping means and symmetrical waveforms with respect to said common level which are similar to the output of said clipping means; and vibrato signal generating means coupled to said means for generating said first and second control signals and driven directly by said first and second control signals for generating a vibrato signal with an amplitude proportional to the potential difference between said first and second control signals.

Claim 7

The arrangement according to claim 4, wherein said, envelope signal generating means includes means for receiving a trigger pulse which is generated in response to key depression, a series combination of a resistor and a capacitor connected across a DC voltage source, and a switching circuit connected in parallel with said capacitor and rendered conductive in response to application of said trigger pulse.

Claim 8

The arrangement according to claim 4, wherein said clipping means includes a diode.

Claim 9

The arrangement according to claim 4, wherein said first and second control signal generating means includes an in-phase amplifier and an inverting amplifier.

Claim 10

A vibrato signal generating arrangement for an electronic musical instrument comprising: envelope signal generating means for generating an envelope signal which changes from a first potential level to a second potential level in response to and at the instant of key depression, and thereafter changes gradually from said second potential level to said first potential level; clipping means coupled to the output of said envelope signal generating means and having a predetermined clipping level between said first and second potential levels for clipping off only a portion of said envelope signal between said second potential level and said clipping level; means coupled to the output of said clipping means for generating first and second control signals having a reference potential level corresponding to the clipped level of output of said clipping means and opposite polarity to each other except for said reference potential level, said control signals having a waveform similar to the output of said clipping means; and vibrato oscillator means coupled to said means for generating said first and second control signals and powered from said first and second control signals for generating a vibrato signal with an amplitude proportional to the potential difference between said first and second control signals.

Claim 11

A vibrato signal generating arrangement for an electronic musical instrument comprising: envelope signal generating means for generating an envelope signal which changes from a first potential level to a second potential level in response to and at the instant of key depression, and thereafter changes gradually from said second potential level to said first potential level; clipping means coupled to the output of said envelope signal generating means and having a predetermined clipping level between said first and second potential levels for clipping off only a portion of said envelope signal between said second potential level and said clipping level; means coupled to the output of said clipping means for generating first and second control signals having a reference potential level corresponding to the clipped level of output of said clipping means and opposite polarity to each other except for said reference potential level, said control signals having a waveform similar to the output of said clipping means; and vibrato oscillator means coupled to said means for generating said first and second control signals and powered from said first and second control signals for generating a vibrato signal with an amplitude proportional to the potential difference between said first and second control signals.

Claim 12

The arrangement according to claim 8, wherein said envelope signal generating means includes means for receiving a trigger pulse which is generated in response to key depression, a series combination of a resistor and a capacitor connected across a DC voltage source, and a switching circuit connected in parallel with said capacitor and rendered conductive in response to application of said trigger pulse.

Claim 13

The arrangement according to claim 8, wherein said clipping means includes a diode.

Claim 14

The arrangement according to claim 8, wherein said means for generating said first and second control signals includes an in-phase amplifier and an inverting amplifier.

Claim 15

The arrangement according to claim 8, wherein said vibrato oscillator means includes a capacitor and means for repeatedly and alternately charging and discharging said capacitor to provide an oscillation signal.

Claim 16

The arrangement according to claim 12, wherein said charging and discharging means is connected in parallel with said capacitor and is responsive to key depression to discharge said capacitor at the instant of key depression.

Claim 17

The arrangement according to claim 8, wherein said vibrato oscillator means includes an operational amplifier having a output, first and second inputs, and first and second power supply terminals connected to receive said first and second control signals respectively, a first resistor connected between the first input and the output of said operational amplifier, second and third resistors connected in series between the output of said operational amplifier and a reference potential level point, the junction between said second and third resistors being connected to the second input of said operational amplifier, and a capacitor connected between the first input of said operational amplifier and said reference potential level point.