Patents by Inventor Chifumi Takeuchi

Chifumi Takeuchi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6410838
    Abstract: A musical sound signal synthesizer with a simple construction for synthesizing complex musical sound waveform signals including many harmonics in a peculiar form. A phase information generator 11 supplies phase information x with a sawtooth wave changing according to a phase of the musical sound to be generated via a calculator 12 to a sine wave table 13, from which output waveform information y is read out. The waveform information y is fed back to the calculator 12 via an absolute value transformer 14, a low pass filter 15 and a gain controller 16. The output waveform information y outputted from the sine table 13 is transformed nonlinearly, which is fed back to the phase information x, which makes a complex change. As a result thereof, the waveform, which is represented by waveform information outputted from the sine wave table 13, becomes peculiar for a musical sound signal synthesized by phase or frequency modulation technique.
    Type: Grant
    Filed: December 8, 2000
    Date of Patent: June 25, 2002
    Assignee: Yamaha Corporation
    Inventor: Chifumi Takeuchi
  • Patent number: 5998724
    Abstract: Basic tone waveform corresponding to a designated tone color and pitch is generated in each of a plurality of channels. Effect is imparted to the basic tone waveform in accordance with an algorithm for providing a predetermined effect, independently for each of the channels. The effect to be imparted is controlled in accordance with the designated tone pitch, separately for each of the channels. The effect impartment may be conducted using a processor, such as a DSP, executing a predetermined program containing a predetermined effect-imparting algorithm. In one example of the effect-imparting algorithm, a delay loop is employed through which an input exciting signal is circulated while being delayed, and an effect specific to an electromagnetic pickup of an electric guitar can be approximated by controlling the delay amount in the delay loop.
    Type: Grant
    Filed: October 21, 1998
    Date of Patent: December 7, 1999
    Assignee: Yamaha Corporation
    Inventors: Chifumi Takeuchi, Toru Kitayama, Toshifumi Kunimoto
  • Patent number: 5969284
    Abstract: A parameter setting apparatus is provided in an electronic music instrument for editing a configure of parameters in accordance with a manipulation amount to set a tone generator which creates a desired timbre of musical tones upon setting. In the apparatus, a first memory device stores a first subset of parameters containing a Boolean parameter having a first Boolean value and a numerical parameter having a first numerical value. A second memory device stores a second subset of parameters containing the Boolean parameter having a second Boolean value and the numerical parameter having a second numerical value. An operating device provides a manipulation amount for editing parameters. An interpolating device interpolates the first numerical value and the second numerical value in accordance with the manipulation amount to determine an edited numerical value of the numerical parameter.
    Type: Grant
    Filed: January 12, 1998
    Date of Patent: October 19, 1999
    Assignee: Yamaha Corporation
    Inventors: Takao Yamamoto, Toshifumi Kunimoto, Takeshi Komano, Chifumi Takeuchi
  • Patent number: 5741994
    Abstract: A musical tone-synthesizing apparatus has a plurality of waveguide networks each including at least one waveguide, each of which has a closed loop in which a circulating signal circulates in response to an external excitation signal. The closed loop has an output through which the circulating signal is output as a waveguide output signal, and an input port through which a signal is input to be superposed on the circulating signal. A network output signal is formed based on the waveguide output signal. A connection means is connected to corresponding ones of the waveguide networks and carries out signal processing on the network output signal delivered from each of the corresponding waveguide networks, based on an external modulating signal, and inputs the resulting processed signal to the input port of the closed loop of each of the corresponding waveguide networks.
    Type: Grant
    Filed: February 27, 1996
    Date of Patent: April 21, 1998
    Assignee: Yamaha Corporation
    Inventor: Chifumi Takeuchi
  • Patent number: 5621801
    Abstract: A reverberation effect imparting system includes plural comb filters, each of which has a signal delay line and a feedback loop for filtering a delayed output signal from the delay line and feeding the filtered signal back to the input side with a variable loop gain. The device further includes a junction section which receives the respective output signals from the delay lines of the plural comb filters. The junction section controls the received signals with respective variable scattering coefficients and sums up the thus-controlled signals, so as to introduce the summed signal into the feedback loop of each of the comb filters. In this manner, reverberation control according to the waveguide theory is performed by the junction section, while the conventional-type reverberation control is performed by the comb filters. Thus, reverberation can be controlled through a combination of the two controls.
    Type: Grant
    Filed: June 9, 1994
    Date of Patent: April 15, 1997
    Assignee: Yamaha Corporation
    Inventors: Toshifumi Kunimoto, Masahiro Kakishita, Chifumi Takeuchi
  • Patent number: 5614685
    Abstract: When a digital signal processor (i.e., DSP) performs a data processing on data stored in a memory (e.g., RAM) in accordance with instructions given from a CPU, data read/write controls are carried out with respect to the data transmitted between the DSP and memory. In accordance with built-in micro-programs, the DSP produces plural musical tone signals in time-division manner. When employing 32-bit data to be processed in the DSP, this 32-bit data is divided into four sets of 8-bit data, which are sequentially written in the memory, for example. Thereafter, the DSP reads such four sets of 8-bit data from the memory, and then, the DSP converts them into the 32-bit data, so that the DSP can perform the predetermined data processing on the converted 32-bit data. Thus, the DSP, employing M-bit data to be processed therein, can be freely coupled with the memory which stores N-bit data (where M.gtoreq.N), as long as "M" is equal to or a multiple of "N".
    Type: Grant
    Filed: July 25, 1994
    Date of Patent: March 25, 1997
    Assignee: Yamaha Corporation
    Inventors: Shuuichi Matsumoto, Chifumi Takeuchi
  • Patent number: 5521325
    Abstract: An apparatus for synthesizing a musical tone comprises a loop circuit for circulating an input wave form signal through a delay circuit, a wave form memory, and a random modulation circuit for modulating the wave form signal stored in the wave form memory. The random modulation circuit generates a random signal, such as a noise signal. The random signal modulates address data to the wave form memory, so that the read wave form data read out from the wave form memory is delicately varied with time.
    Type: Grant
    Filed: March 19, 1992
    Date of Patent: May 28, 1996
    Assignee: Yamaha Corporation
    Inventors: Chifumi Takeuchi, Toshifumi Kunimoto, Norio Suzuki, Takaaki Muto
  • Patent number: 5432296
    Abstract: The musical tone synthesizing apparatus is mainly configured by a closed loop which at least provides a delay circuit and an all-pass filter. The delay circuit delays an input signal (e.g., excitation wave signal) by a first delay time corresponding to a certain integral number of sampling periods. The all-pass filter functions to at least delay an output of the delay circuit by a second delay time corresponding to a decimal fraction of the sampling period, so that an output of the all-pass filter is fed back to the delay circuit. The whole delay time of the closed loop consists of the first and second delay times which can be respectively controlled. Thus, a musical tone signal representing a synthesized musical tone (e.g., an attenuating sound which is produced from an percussion instrument) is picked up from the closed loop. Incidentally, the whole configuration of the closed loop can be embodied by a digital signal processor (DSP).
    Type: Grant
    Filed: August 18, 1993
    Date of Patent: July 11, 1995
    Assignee: Yamaha Corporation
    Inventors: Chifumi Takeuchi, Iwao Higashi
  • Patent number: 5308918
    Abstract: The present invention provides a signal delay circuit for substantially steplessly changing a delay interval. The signal delay circuit is composed essentially of a delay controller, a first delay circuit, and a second delay circuit. The delay controller generates and outputs control data consisting of a real number bearing control information for controlling the delay interval, the real number consists of an integral portion and a fractional portion. The first delay circuit receives an incidental signal, delays the incidental signal for creating a first intermediate signal, and outputs the first intermediate signal, the first intermediate signal being delayed with respect to the incidental signal by an interval which is a product of a predetermined cardinal interval and the integral portion of the real number.
    Type: Grant
    Filed: April 16, 1992
    Date of Patent: May 3, 1994
    Assignee: Yamaha Corporation
    Inventors: Akira Yamauchi, Toshifumi Kunimoto, Chifumi Takeuchi, Iwao Higashi
  • Patent number: 5256830
    Abstract: A musical tone synthesizing apparatus is designed to simulate the acoustic sounds of non-electronic musical instruments. In the non-electronic musical instrument providing the resonator such as the piano and guitar, the produced acoustic sound contains three kinds of sounds, i.e., a direct sound, a resonant sound and a transient sound. Herein, the direct sound is produced directly by playing the instrument, the resonant sound is produced from the resonator based on the direct sound and the transient sound is produced when the impulse to be occurred by playing the instrument propagates through the resonator. Thus, signals simulating these sounds respectively are mixed together so as to produce the synthesized musical tone signal, which well-simulates the acoustic sound.
    Type: Grant
    Filed: September 11, 1990
    Date of Patent: October 26, 1993
    Assignee: Yamaha Corporation
    Inventors: Chifumi Takeuchi, Toshifumi Kunimoto
  • Patent number: 5245127
    Abstract: The present invention provides a signal delay circuit for substantially steplessly changing a delay interval. The signal delay circuit is composed essentially of a delay controller, a first delay circuit, and a second delay circuit. The delay controller generates and outputs control data consisting of a real number bearing control information for controlling the delay interval, the real number consists of an integral portion and a fractional portion. The first delay circuit receives an incidental signal, delays the incidental signal for creating a first intermediate signal, and outputs the first intermediate signal, the first intermediate signal being delayed with respect to the incidental signal by an interval which is a product of a predetermined cardinal interval and the integral portion of the real number.
    Type: Grant
    Filed: April 16, 1992
    Date of Patent: September 14, 1993
    Assignee: Yamaha Corporation
    Inventors: Akira Yamauchi, Toshifumi Kunimoto, Chifumi Takeuchi, Iwao Higashi
  • Patent number: 5241129
    Abstract: An object of the present invention is to provide an electronic musical instrument which can generate a plurality of tones in spite of the inexpensive and simple structure thereof and can correct the quantity of phase delay of a closed loop in a physical model tone generator without use of any special processor such as a high-speed CPU or a dedicated numerical operation processor, not only to thereby attain performance effects of echo, chorus and the like but to simulate a performance style of repeating the operation of one string or key in the condition in which a tone corresponding to the string or key remains, without production of noise even when parameters for constituent elements of the physical model tone generator are respectively changed widely. The electronic musical instrument includes a driving waveform for storing a plurality of driving waveform data corresponding to performance information in advance, and a closed loop constituted by a shift register and a low-pass filter.
    Type: Grant
    Filed: February 11, 1992
    Date of Patent: August 31, 1993
    Assignee: Yamaha Corporation
    Inventors: Takaaki Muto, Chifumi Takeuchi
  • Patent number: 5223657
    Abstract: A musical tone generating device is capable of simulating various special playing techniques for a stringed instrument in which the harmonic spectrums of produced sound is enhanced, or otherwise altered. The device includes a delay circuit wherein an input signal thereto is delayed and output; a closed loop circuit comprising multiple feedback pathways to which the output of the delay circuit is supplied and processed therein, after which the processed signal is returned toward the delay circuit as an input signal; an excitation device in response to a predetermined control signal, generating an excitation signal and supplying it to the closed loop circuit, such that the excitation signal corresponds to an excitation vibration in the stringed instrument being simulated; and a control device wherein the predetermined control signal is generated and whereby the delay interval of the delay circuit and the processing carried out in the multiple feedback pathways are controlled.
    Type: Grant
    Filed: February 21, 1991
    Date of Patent: June 29, 1993
    Assignee: Yamaha Corporation
    Inventor: Chifumi Takeuchi
  • Patent number: 5223653
    Abstract: A musical tone synthesizing apparatus which is suitable for simulating and synthesizing the percussion instrument tone provides a closed-loop including at least an adder and a delay circuit. An input signal corresponding to a musical tone signal to be synthesized is supplied to the adder from an external device. The adder adds the input signal to its feedback signal. The output of adder is delayed by a delay time in the delay circuit, wherein delay time is controlled by a modulation signal. Then, delayed output of the delay circuit is fed back to the adder as the feedback signal. Thus, the output of adder or a signal propagating the delay circuit is picked up as a synthesized musical tone signal. Preferably, it is possible to provide a plurality of delay circuits.
    Type: Grant
    Filed: May 15, 1990
    Date of Patent: June 29, 1993
    Assignee: Yamaha Corporation
    Inventors: Toshifumi Kunimoto, Chifumi Takeuchi
  • Patent number: 5000074
    Abstract: A variable delay circuit for delaying an input signal and being capable of changing length of this delay is provided and various modulation effects are imparted by this delay. When change in the delay length has been designated, a decay envelope is imparted to a delay output tone signal corresponding to the delay length before the change and then a rise envelope is imparted to a delay output signal corresponding to the delay length after the change. Generation of a click noise during the change in the delay length thereby is prevented. Alternatively, when the delay length is to be changed, a decay envelope is imparted to a delay output signal corresponding to the delay length before the change and, simultaneously, a rise envelope is imparted to a delay output tone signal corresponding to the delay length after the delay and the two signals are combined.
    Type: Grant
    Filed: June 23, 1989
    Date of Patent: March 19, 1991
    Assignee: Yamaha Corporation
    Inventors: Toshihiro Inoue, Akira Iizuka, Chifumi Takeuchi
  • Patent number: 4766795
    Abstract: A musical tone signal is synthesized on the basis of a predetermined modulation operation (e.g. an FM or AM operation) employing a modulation signal and a carrier signal respectively having an audio range frequency. In a waveshape table provided for defining at least one of a modulation wave function or a carrier wave function, a wave function expressed in a logarithmic form log{f(x)} is stored. The wave function log{f(x)} read out from this waveshape table is multiplied with a coefficient k whereby the wave function of the modulation signal or the carrier signal to be used in the modulation operation is changed from f(x) to {f(x)}.sup.k. That is, k log{(f(x)}=log{f(x)}.sup.k is obtained by this multiplication and {f(x)}.sup.k is obtained by converting this log {f(x)}.sup.k to a linear form. Therefore, it is enabled to synthesize a tone having abundant frequency components by using the wave function {f(x)}.sup.k obtained by a simple operation.
    Type: Grant
    Filed: October 10, 1984
    Date of Patent: August 30, 1988
    Assignee: Nippon Gakki Seizo Kabushiki Kaisha
    Inventor: Chifumi Takeuchi
  • Patent number: 4552051
    Abstract: In an electronic musical instrument comprising a keyboard including a plurality of keys, a tone signal generator for producing a musical tone signal corresponding to a depressed key, a key touch detector for generating a key touch signal concerning a key depression operation of the depressed key, and an operator for controlling one of musical tone components of the musical tone signal, there are provided a selector for selecting either one of two control elements comprising the operating state of the operator and the key touch state at the time of key depression for determining whether the degree of control of the musical element caused by the selected control element is to be emphasized or not, and a suppression circuit for inhibiting or suppressing the musical tone control effected by the other control element in accordance with the state of selection of the selector.
    Type: Grant
    Filed: October 25, 1983
    Date of Patent: November 12, 1985
    Assignee: Nippon Gakki Seizo Kabushiki Kaisha
    Inventor: Chifumi Takeuchi
  • Patent number: 4256004
    Abstract: An electronic musical instrument is of a harmonic synthesis type and is provided with an order number memory device which stores a plurality of order numbers of the harmonic components necessary to form respective tone colors, an amplitude coefficient memory device which stores a plurality of sets of amplitude coefficients for the respective harmonic components corresponding to the respective order of numbers stored in the order number memory device, and a tone color selector which controls the order number memory device and the amplitude coefficient memory device, when a certain tone color is selected, for causing the respective memory devices to produce the order numbers and the amplitude coefficients of a set corresponding to the selected tone color.
    Type: Grant
    Filed: April 20, 1979
    Date of Patent: March 17, 1981
    Assignee: Nippon Gakki Seizo Kabushiki Kaisha
    Inventor: Chifumi Takeuchi
  • Patent number: RE31653
    Abstract: An electronic musical instrument is of a harmonic synthesis type and is provided with an order number memory device which stores a plurality of order numbers of the harmonic components necessary to form respective tone colors, an amplitude coefficient memory device which stores a plurality of sets of amplitude coefficients for the respective harmonic components corresponding to the respective order of numbers stored in the order number memory device, and a tone color selector which controls the order number memory device and the amplitude coefficient memory device, when a certain tone color is selected, for causing the respective memory devices to produce the order numbers and the amplitude coefficients of a set corresponding to the selected tone color.
    Type: Grant
    Filed: September 30, 1982
    Date of Patent: August 28, 1984
    Assignee: Nippon Gakki Seizo Kabushiki Kaisha
    Inventor: Chifumi Takeuchi