Modulation Patents (Class 84/624)
  • Patent number: 5389730
    Abstract: An emphasize system for an electronic musical instrument including filter and control device. The filter extract and output predetermined frequency range component of an input musical tone signal. The control device control the level of an output from the filter at least on the basis of an output from an envelope generator which controls the level of the input musical tone signal, or on the basis of the level of another frequency range component of the input musical tone signal. At least the level controlled signal is outputted from the system.
    Type: Grant
    Filed: March 20, 1991
    Date of Patent: February 14, 1995
    Assignee: Yamaha Corporation
    Inventor: Masatada Wachi
  • Patent number: 5383386
    Abstract: An addition section and a memory section for storing data to be inputted to the addition section are provided. A processing section variably performs a logical processing on output data of the memory section in accordance with a control signal and gives the data to the addition section. A control section controls introduction of data to the memory section and supply of the control signal to the processing section in correspondence to respective desired operations so that plural kinds of operations for tone signal generation may be respectively performed. With this arrangement, the addition section can be shared for various kinds of operations for the tone signal generation. Consequently, operation circuits for performing the various operations are integrated, so as to realize a substantial reduction of circuitry construction.
    Type: Grant
    Filed: April 14, 1993
    Date of Patent: January 24, 1995
    Assignee: Yamaha Corporation
    Inventors: Masaki Kudo, Tokio Shirakawa
  • Patent number: 5371315
    Abstract: The position of a connecting portion between waveforms can be arbitrarily set when a plurality of waveform data is obtained by changing pitch widths of stored external sound waveform data, when a read rate of the waveform data is increased or decreased and the readout waveform data is synthesized, or when the waveform is changed from one waveform to another waveform. In addition, a plurality of loop reproduction cycles can be arbitrarily set when the waveform data is to be read out. In loop reproduction, two items of waveform data having different phases between the preset start and end addresses can be repeatedly read out and synthesized, and their mixing ratios can be changed as a function of time, thereby performing loop reproduction so as not to abruptly change amplitude values of the waveforms.
    Type: Grant
    Filed: June 10, 1993
    Date of Patent: December 6, 1994
    Assignee: Casio Computer Co., Ltd.
    Inventors: Kohtaro Hanzawa, Kunihiro Sugita, Hiroyuki Sasaki
  • Patent number: 5359146
    Abstract: A musical tone synthesizing apparatus provides a time-varying signal processing circuit the transfer function of which gradually varies over time in order to gradually vary over time the tone color of a synthesized musical tone. A number of time-varying signal processing circuits are presented. An interpolation-type-time-varying signal processing circuit is provided with interpolators for interpolating control parameters generated based on a desired musical tone, a signal processing circuit carrying out a signal operation based on the interpolated control parameters on an input signal incomming thereto.
    Type: Grant
    Filed: February 19, 1992
    Date of Patent: October 25, 1994
    Assignee: Yamaha Corporation
    Inventors: Tomoyuki Funaki, Iwao Higashi, Toru Kitayama, Hideyuki Masuda, Toshifumi Kunimoto
  • Patent number: 5354948
    Abstract: Two tone sources having different tone generation systems such as an FM tone source and a PCM tone source are provided. Tone signals are generated in the two tone sources in response to tone generation designation information such as keyboard performance information. One of the tone sources synthesizes a tone by employing a modulation operation such as FM or AM and, as a modulating signal supplied thereto, an output tone signal of the other tone source can be selectively used. A single complex tone color is constructed of plural element tone colors and which tone source should generate a partial tone signal corresponding to each element tone color can be designated individually with respect to each element tone color in response to element type information. With respect to a desired element tone color, editing of contents of its parameter information can be made as desired.
    Type: Grant
    Filed: October 2, 1990
    Date of Patent: October 11, 1994
    Assignee: Yamaha Corporation
    Inventor: Hiroyuki Toda
  • Patent number: 5313013
    Abstract: A loop circuit including a delay element and an all-pass filter circulates a tone signal. A driving waveform is applied to the loop circuit. The delay element provides a delay time corresponding to the pitch of the circulating tone signal and the all-pass filter is capable of changing the phase of the tone signal corresponding to its frequency. Thus, the resulting musical tone can be controlled in accordance with touch, thereby enabling the simulation of vibration of pitch and the generation of non-harmonic components caused by touch in a natural musical instrument.
    Type: Grant
    Filed: July 30, 1991
    Date of Patent: May 17, 1994
    Assignee: Yamaha Corporation
    Inventors: Norio Suzuki, Takaaki Muto
  • 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: 5298676
    Abstract: A plurality of groups of tone parameters different in kind required for the generation of a musical sound is stored. The tone parameters of the same kind among those tone parameters are modulated with the same sway signal generated at the same time at a desired time or at fixed intervals of time when a key concerned is depressed. The modulated parameters are either restored in the original storage region or directly delivered to a sound source. The resulting musical sound has an acoustically natural comfortable tone quality. Even if musical sounds are generated simultaneously, no sways in the respective tones of the musical sound are canceled.
    Type: Grant
    Filed: January 12, 1993
    Date of Patent: March 29, 1994
    Assignee: Casio Computer Co., Ltd.
    Inventors: Hiroyuki Sasaki, Kohtaro Hanzawa, Jun Yoshino, Toshiaki Kawanishi, Masatoshi Watanuki
  • Patent number: 5284080
    Abstract: A tone generating apparatus comprises a wave memory for consecutively storing first tone wave data acquired by performing pulse code modulation on a tone waveform in a first predetermined interval starting at an attack of a musical tone, second tone wave data provided by adding that tone wave data which is obtained by performing pulse code modulation on a tone waveform in a second predetermined interval following the first predetermined interval and is then weighted with a fade-out characteristic and that tone wave data which is acquired by synthesizing waveform components of a tone waveform in a third predetermined interval following the second predetermined interval and is then weighted with a face in-characteristic after being linked for the second predetermined interval, and third tone wave data produced by synthesizing waveform components of a tone waveform in a third predetermined interval following the second predetermined interval based on a characteristic of the tone waveform in the third predetermin
    Type: Grant
    Filed: April 29, 1991
    Date of Patent: February 8, 1994
    Assignee: Kabushiki Kaisha Kawai Gakki Seisakusho
    Inventors: Atsushi Noguchi, Yasushi Sato
  • Patent number: 5254805
    Abstract: An electronic musical instrument has a low frequency oscillator (LFO) for generating a low-frequency signal to impart musical effect such as vibrato to musical tones, and a plurality of tone generating channels. The LFO comprises a random access memory (RAM), a feedback loop, and a waveform generator. The LFO generates the low-frequency signal in accordance with the designated RAM addresses corresponding to the designated tone color to impart a same phase musical effect to the plurality of channels having same tone color.
    Type: Grant
    Filed: March 19, 1991
    Date of Patent: October 19, 1993
    Assignee: Yamaha Corporation
    Inventor: Akira Iizuka
  • 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: 5243124
    Abstract: A computer having one or more wave tables stored therein is used to synthesize sounds represented by a series of digital samples produced at a sample rate by specifying parameters including a carrier frequency, a modulating frequency and an index of modulation. At each sample time, a modulation value determined during an immediately preceding sample time is scaled to produce a digital control signal. Also at each sample time the modulation value to be used during an immediately succeeding sample time is read from a location of a wave table determined by the modulating frequency, and a carrier value used to produce the digital samples is read from a location of a wave table determined by the carrier frequency and the digital control signal. Modulation effects are therefore delayed by one sample in order to speed execution of the method using the computer.
    Type: Grant
    Filed: March 19, 1992
    Date of Patent: September 7, 1993
    Assignee: Sierra Semiconductor, Canada, Inc.
    Inventors: Clifford Kondratiuk, Karim Mitha
  • Patent number: 5243658
    Abstract: A modulation effect adding apparatus in which when an input signal is written into a memory and read and output with a given delay time, the delay time is changed depending on an LFO waveform to thereby add a modulation effect to the input signal. The LFO waveform is obtained by passing through a low pass filter a waveform signal comprising multiple high harmonic components and changing in a positive- or negative-going direction at a particular period. By changing the characteristic of the low pass filter, various LFO waveforms are obtained. An offset value corresponding to the maximum peak value of the LFO waveform is added to the LFO waveform, and the resulting waveform is multiplied by an offset value having a predetermined magnification and inverting the waveform signal to thereby prevent a memory read address from disadvantageously exceeding a write address.
    Type: Grant
    Filed: July 19, 1991
    Date of Patent: September 7, 1993
    Assignee: Casio Computer Co., Ltd.
    Inventor: Goro Sakata
  • Patent number: 5241127
    Abstract: The musical tone synthesizing apparatus simulating the musical tones of a natural musical instrument such as a piano. The apparatus contains a closed-loop circuit for simulating the vibration mechanism of the strings and a excitation circuit for generating excitation signals to the closed-loop circuit, so that the excitation circuit simulates the hammer striking the string. The apparatus also contains a scaling coefficient generating circuit for generating and supplying scaling coefficients to the excitation circuit, where the scaling coefficients represent the influence rate corresponding to the influence to be applied to the hammer by the string. In the excitation circuit, the excitation signals are multiplied by the scaling coefficients so that a slight difference of tone color is applied to the excitation signals with respect to tone pitch (or each key).
    Type: Grant
    Filed: December 20, 1990
    Date of Patent: August 31, 1993
    Assignee: Yamaha Corporation
    Inventor: Kaoru Kobayashi
  • 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: 5218156
    Abstract: A musical tone synthesizing apparatus comprising FM operators and connection control device. At least one of the FM operators comprises a waveform memory, phase data generation device, and output inversion device. The waveform memory stores fundamental waveform data. The phase data generation device generates phase data as an address signal for accessing the waveform memory on the basis of a musical tone designation signal and a modulation signal inputted from an external circuit. The output inversion device selects whether a waveform signal read out from the waveform memory is outputted after sign inversion, or is outputted directly. The connection control device arbitrarily combine connections of the FM operators.
    Type: Grant
    Filed: March 19, 1991
    Date of Patent: June 8, 1993
    Assignee: Yamaha Corporation
    Inventors: Akira IIzuka, Kenji Kawakami
  • Patent number: 5206446
    Abstract: An electronic musical instrument has a tone generation mode selecting switch capable of selecting a tone generation mode associated with an arbitrary one of a keyboard instrument play mode, a stringed instrument play mode and a wind instrument play mode, and a CPU for controlling the tone generation mode for a tone generator in accordance with the selection. This electronic musical instrument serving as a so-called tone generator module, can be driven by a MIDI signal supplied to a MIDI circuit from an external unit.
    Type: Grant
    Filed: January 16, 1990
    Date of Patent: April 27, 1993
    Assignee: Casio Computer Co., Ltd.
    Inventors: Naoaki Matsumoto, Hitoshi Ando, Jun Yoshino, Hitoshi Kato
  • Patent number: 5191161
    Abstract: In this electronic musical instrument a musical tone is generated by repetitively reading out a waveshape stored in a memory. Repetitive sets of phase information are produced, such phase information thus being a linear saw-tooth-like digital signal having a repetition period corresponding to the frequency of the generated musical tone. Phase distorting means modifies the shape of the phase information so as to distort said linear saw-tooth-like signal, without changing the repetition period thereof. The resultant altered phase information is used to access said memory so that during the supply of each of said repetitive sets, successive samples in different portions of said stored waveshape respectively are read out at different effective rates. Thus the waveshape samples read out from said memory will constitute a musical tone having changed tone color but unchanged pitch.
    Type: Grant
    Filed: October 15, 1987
    Date of Patent: March 2, 1993
    Assignee: Yamaha Corporation
    Inventor: Akiyoshi Oya
  • Patent number: 5180877
    Abstract: A musical tone synthesizing apparatus synthesizes musical tones by simulating the tone generation construction of a plucked-string or struck-string instrument. The apparatus has a loop circuit which simulates a vibrating element of the instrument, an excitation circuit creates an excitation signal corresponding to the excitation given to the vibrating element in response to the operation of operators such as a pick or a hammer or the state of the generation body and a memory which stores a non-linear relation between the operator and the vibration element. The excitation signal circulates around the loop circuit and is delayed by means of a delay circuit with a previously determined delay interval, and is fed back into the excitation circuit as the state of the vibrating element.
    Type: Grant
    Filed: July 26, 1990
    Date of Patent: January 19, 1993
    Assignee: Yamaha Corporation
    Inventor: Toshifumi Kunimoto
  • Patent number: 5164530
    Abstract: A musical sound waveform generator includes a carrier signal generating unit, a modulation signal generating unit, a mixing controlling unit and a waveform outputting unit. The characteristics of the carrier signal from the carrier signal generating unit are determined such that the musical sound waveform generated by the waveform outputting unit is a sine wave or a cosine wave with a single frequency, where the mixing ratio of the modulation signal is made 0 by the mixing controlling unit. Therefore, the mixing controlling unit presets the mixing ratio of the modulation signal to be 0, making it possible to generate a musical sound waveform which is only a sine wave or a cosine wave of a single frequency. During the performance, the mixing ratio can, for example, be determined at a high value immediately after the start of sound generation and thereafter reduced to near 0 with time.
    Type: Grant
    Filed: December 27, 1989
    Date of Patent: November 17, 1992
    Assignee: Casio Computer Co., Ltd.
    Inventor: Hiroshi Iwase
  • Patent number: 5159142
    Abstract: A performance apparatus for producing a mixed musical tone signal having a comparator and a modulator. The comparator detects key data corresponding to musical tones having the same pitch and the same or similar tone colors from key data of musical tones to be mixed. The modulator changes at least a tone element of the mixed musical tone signal on the basis of the key data detected by the comparator to produce tones having multiple-tone like tone colors. The modulator comprises a detuner for detuning pitches of some musical tones of a plurality of musical tones formed based on the key data detected by the comparator, or comprises a modulator for modulating an amplitude or a frequency of the musical tone signal formed and mixed bases on the key data detected by the comparator.
    Type: Grant
    Filed: January 3, 1990
    Date of Patent: October 27, 1992
    Assignee: Yamaha Corporation
    Inventor: Takashi Ishida
  • Patent number: 5157215
    Abstract: An electrical musical instrument includes a scale designator for sequentially and automatically designating a scale on the basis of prestored data of a music piece, and a musical tone signal generator for outputting a musical tone signal including a harmonic frequency on the basis of the scale designated by said scale designator or as a fundamental frequency. A voice detector detects an external voice and the detected voice is divided by a modulator into voice signals in a plurality of frequency ranges. The musical tone signal is modulated in units of corresponding frequency ranges on the basis of the voice signals divided into the plurality of frequency ranges.
    Type: Grant
    Filed: September 14, 1990
    Date of Patent: October 20, 1992
    Assignee: Casio Computer Co., Ltd.
    Inventors: Tetsuichi Nakae, Takashi Matsuda
  • Patent number: 5138927
    Abstract: A formant tone generating apparatus provides n (where n=1, 2, . . . ) systems each capable of generating a pitch control signal by a timing of which period is n times longer than a fundamental pitch period of a musical tone including a formant tone to be generated. Then, a periodic function such as a sinewave function having a formant center frequency is modulated by use of a window function under control of the pitch control signal, so that a modulated signal is formed with respect to each system. Such modulated signals are synthesized together with respect to one or more systems, so that a synthesized signal is obtained. Based on the synthesized signal, the formant tone can be generated without forming unnecessary spectrum.
    Type: Grant
    Filed: March 27, 1990
    Date of Patent: August 18, 1992
    Assignee: Yamaha Corporation
    Inventor: Tetsuo Nishimoto
  • Patent number: 5136917
    Abstract: A musical tone synthesizing apparatus has a closed-loop configuration including an adder, a filter and a delay circuit. The adder adds its feedback signal to a signal to be synthesized which is applied from an external device. The filter constructed as the all-pass filter has a frequency characteristic by which a phase delay between its input and output signals is varied in response to a frequency variation of its input signal. Such all-pass filter includes a delay element having a delay time which is set longer than a predetermined unit delay time corresponding to a sampling period to be employed. Herein, the output of adder is fed back to the adder via the all-pass filter and delay circuit as the feedback signal. Thus, a signal circulating the closed-loop is picked up as a synthesized musical tone signal.
    Type: Grant
    Filed: May 15, 1990
    Date of Patent: August 11, 1992
    Assignee: Yamaha Corporation
    Inventor: Toshifumi Kunimoto
  • Patent number: 5109746
    Abstract: An envelope generator for use in an electronic musical instrument comprises a musical tone data processing unit to evaluate a rate of change in a current value of musical tone envelope data with respect to a target value based on a parameter, a changing rate control unit for decrementing a change in the current value such that the current value becomes closer to the target value, a detection unit to detect whether or not the rate of change becomes equal to 0, and a processing control unit control for stopping the evaluation the current value in response to a result of the detection.
    Type: Grant
    Filed: March 27, 1990
    Date of Patent: May 5, 1992
    Assignee: Kawai Musical Inst. Mfg. Co., Ltd.
    Inventors: Kiyomi Takauji, Yutaka Washiyama
  • Patent number: 5094136
    Abstract: Two tone generators having different tone generation systems, e.g., PCM type and FM type, are provided. There are tone generation modes designating combination of tone generation in these tone generators and one can be selected from among them. There are, for example, a simple mixing mode, a delay mode in which start of tone generation in one tone generator is delayed from that in the other and a crossfade mode in which a tone signal is generated first in one tone generator and tone generation is switched to the other tone generator and envelope levels of output tone signals of the two tone generators are crossfaded during a switching period. Delay time in the delay mode and switching time in the crossfade mode can be variably controlled in accordance with a key scaling and/or other factors. A tone may be generated at a sampling frequency synchronized with a pitch in one tone generator and at a sampling frequency which is not synchronized with the pitch in the other tone generator.
    Type: Grant
    Filed: January 3, 1990
    Date of Patent: March 10, 1992
    Assignee: Yamaha Corporation
    Inventors: Masaki Kudo, Tokio Ogi, Tsutomu Yanase, Tetsuji Ichiki
  • Patent number: 5088379
    Abstract: A melody generating system is fabricated from a switch unit operative to produce an activation signal, an analog signal producing unit responsive to the activation signal and producing an analog melody signal carrying pieces of melody information used for reproducing a melody and a sound unit responsive to the analog melody signal for reproducing the melody, wherein the analog signal producing unit comprises an analog signal producing circuit integrated on a single semiconductor chip and responsive to the activation signal for producing a read out controlling signal and a memory circuit storing the pieces of melody information and responsive to the read out controlling signal for producing a digital melody information carrying signal, and the analog signal producing circuit is further responsive to the digital melody information carrying signal for producing the analog melody signal, so that a system supplier easily copes with a request for a new melody by changing the pieces of melody information stored in t
    Type: Grant
    Filed: March 14, 1990
    Date of Patent: February 18, 1992
    Assignee: Yamaha Corporation
    Inventor: Manabu Komiyama
  • Patent number: 5076133
    Abstract: A musical tone signal generating apparatus provides at least plural modulation operation systems and plural memories, wherein each of the modulation operation systems carries out the predetermined modulation operation on each of plural pieces of input information applied thereto so that each of the memories stores the operation result thereof as the waveform information. These modulation operation systems are connected together such that plural pieces of waveform information stored in the memories are selectively supplied to each modulation operation system. By changing over the connections between the modulation operation systems and memories in the time-sharing system, the waveform operation is carried out based on the predetermined algorithms for forming the musical tone signal. Preferably, the predetermined modulation operation is the frequency-modulation operation.
    Type: Grant
    Filed: October 10, 1990
    Date of Patent: December 31, 1991
    Assignee: Yamaha Corporation
    Inventor: Hiroyuki Toda
  • Patent number: 5038661
    Abstract: A plurality of waveforms are time-divisionally obtained from a waveform generator in one sampling period under the control of a controller. The sampling period is equally divided into a plurality of module periods. Each module period is also divided to correspond to the number of waves which are obtained time-divisionally. The waveform generator includes a selector which uses waveform data produced in a preceding module in the sampling period as that for waveform generation in the following module.
    Type: Grant
    Filed: January 5, 1989
    Date of Patent: August 13, 1991
    Assignee: Casio Computer Co., Ltd.
    Inventor: Yoji Kaneko
  • Patent number: 4998960
    Abstract: A music synthesizer is constructed according to a modular scheme with plural, substantially interchangeable voice units. During operation, these voice units are used to simulate different instruments. The voice units operate under control of a master computer, and take waveform data from a common memory through a common digital data bus. The actions of each voice unit in simulating a note are controlled according to a plurality of control parameters. These control parameters are derived by interpolating between plots of each control parameter versus time for a weak actuation (soft note) and a strong actuation (hard note) condition. The synthesizer is arranged to simulate the effects caused by the interactions between closely spaced excitations of the same instrument such as closely spaced strikes upon a drumhead, by varying the qualities of the sound. The synthesizer may also serve as a mixer or as a multichannel signal processing device.
    Type: Grant
    Filed: September 30, 1988
    Date of Patent: March 12, 1991
    Assignee: Floyd Rose
    Inventors: Floyd D. Rose, John C. Ragin, III, Ronald H. Randall, Jr.
  • Patent number: 4942799
    Abstract: A tone generation system and method generates tone signals having complex harmonic components while reducing aliasing noise resulting from sampling of high frequency harmonics.In a first step, waveshape data which has been sampled with a second sampling frequency which is higher than a first sampling frequency is obtained. Then a predetermined tone synthesis modulation operation is performed, using this waveshape data as at least one of a signal to be modulated and a modulating signal. By performing this modulation operation in accordance with the higher second sampling frequency, occurrence of an aliasing component contained in a tone signal obtained as the output of the modulation operation in a frequency band below a frequency which is 1/2 of the first sampling frequency can be prevented. Then, the frequency band of the output signal of the modulation operation is limited to a frequency band below the frequency which is 1/2 of the first sampling frequency.
    Type: Grant
    Filed: October 22, 1987
    Date of Patent: July 24, 1990
    Assignee: Yamaha Corporation
    Inventor: Hideo Suzuki
  • Patent number: 4924744
    Abstract: In an apparatus for generating sound, there are provided a plurality of channels for generating sounds. Each of the channels includes a memory for storing waveform data, and at least one of the channels includes a noise generator so that various kinds of sounds including rhythm sound-effects sound, effects sound-vibrato etc. are generated. There is further provided a controller by which voice sound signal is passed through the channels so that artificial sound, voice sound etc. are generated. There is still further provided a circuit for adjusting an amplitude level of a whole sound which is obtained by mixing output sounds of the channels so that far and near sound is produced. Further, each of the channels includes left and right attenuators which divide a channel sound into left and right channel sounds.
    Type: Grant
    Filed: August 9, 1988
    Date of Patent: May 15, 1990
    Assignee: Hudson Soft Co., Ltd.
    Inventor: Kimio Yamamura
  • Patent number: 4922795
    Abstract: A parameter generation circuit sequentially generates different tone forming parameters by timewise changing them in a predetermined sequence. A sequence control circuit performs a control so as to repeat the sequential generation of the different tone forming parameters in the parameter generation circuit. The sequentially generated tone forming parameters are applied to a tone forming circuit in which a tone signal having tone color characteristics based on these tone forming parameters is formed. The tone color characteristics of the tone signal formed undergo timewise change due to the timewise change in the tone forming parameters. By repeating the sequential generation sequence of the tone forming parameters, an adequate tone color variation can be realized notwithstanding that a relatively small number of tone forming parameters may be used.
    Type: Grant
    Filed: November 16, 1988
    Date of Patent: May 8, 1990
    Assignee: Yamaha Corporation
    Inventor: Hideo Suzuki
  • Patent number: RE34481
    Abstract: An electronic musical instrument includes circuitry for modifying an ordinary address signal which changes at a uniform rate over one cycle of a waveform, into a modified address signal whose rate varies in one cycle of the waveform by the use of a modification signal.The modified address signal accesses a storage device such as a ROM in which waveform data is stored, thereby producing the modified waveform data from the storage device. The modification signal is obtained from the ordinary address signal through a predetermined logic circuit.
    Type: Grant
    Filed: January 15, 1991
    Date of Patent: December 21, 1993
    Assignee: Casio Computer Co., Ltd.
    Inventor: Masanori Ishibashi, deceased