Abstract: The present invention discloses a digital processing device with smooth-clipping function and a digital musical tone synthesizing device using it. When one or a plurality of digital values are input to the digital processing device and a smooth-clipping mode is activated, an overflow during processing of the digital values is avoided as the internal resulting value of the device is scaled down before it is output. The scaling down of the internal resulting value is continuously increased in dependence on the increase of the value of the internal resulting value, such that an overflow is avoided. For example, if the digital processing device is performing a summation of two digital operands in a digital musical tone forming device, the time behavior of the resulting tone signal slope is smooth and thus the sound dynamics are improved and sound distortions are avoided during sound reproduction.

Abstract: The touch dynamics of the operation of keys of an electronic musical instrument are determined through the use of pressure sensitive transducers associated with the keys, the transducers each including a magnetic field responsive semiconductor device and providing signals which are analyzed to determine their variation in magnitude as a function of time. Additionally, after a pre-selected time period, if a key remains operated and the pressure exerted thereon is varied, the output voltage of the key associated transducer will be further analyzed to determine if the player is calling for the reproduction of a secondary effect.

Abstract: The realism by which the sound produced by various musical instruments may be electronically simulated is enhanced by the storage of digital data commensurate with scanning values of several periods of a note including the release portion thereof. Command words are also memorized and, in response to the reading of a command word and the state of the input command to the instrument by the player, indicative of whether the note is to be sustained or terminated, the reading of a command word may cause the addressing of the waveform memory to be jumped to the release portion where the read-out will be continued from a scanning value approximately equal to the value read immediately prior to the reading of the command word. The waveform memory may contain a segment of the sustain portion of the note which will be repetitively read so long as the player's input command indicates that the note is to be sustained, the repetition also being in response to memorized command words.

Abstract: The touch dynamics of the operation of keys of an electronic musical instrument are determined through the use of pressure sensitive transducers associated with the keys, the transducers providing signals which are analyzed to determine their variation in magnitude as a function of time. Additionally, after a preselected time period, if a key remains operated and the pressure exerted thereon is varied, the output voltage of the key associated transducer will be further analyzed to determine if the player is calling for the reproduction of a secondary effect.

Abstract: An "orchestra effect" is produced in an electronic musical instrument by mixing a signal at the commanded frequency with a second signal which is displaced in frequency from the commanded signal, the second signal also periodically varying in frequency. The difference in frequencies between the commanded signal and the signal which is mixed therewith is preferably less than one-half the total variation in frequency of the latter signal.

Abstract: The identification of the last-actuated of a plurality of parallel connected switches is provided by energizing a light source associated with the last-actuated switch and by providing a coded output signal which identifies the switch. The identification of a closed switch is accomplished through the use of logic circuitry which periodically imposes a potential difference across all of the switch associated light sources. The potential difference is sensed via the closed switch and functions as an initiation signal which causes generation of a coded output signal and maintains energization of the light source.

Abstract: Envelope curves for a large number of individual sounds to be digitally synthesized are generated by storing sample envelope shapes. The duration of the stored curves is varied by exercising control over the sampling of the stored envelopes. The smooth transition from one envelope curve to another is accomplished by sampling the new curve at a fast rate until substantially matching values of the previous and new curve are found and then proceeding with the sampling of the new curve at the desired rate.

Abstract: An electronic musical instrument has the switch contacts associated with the keyboard and with the other user operated controls arranged in a single matrix with the switch contacts being grouped in the matrix such that, for example, all of those switches associated with keys are in one corner of the matrix. This arrangement and grouping of switch contacts allows the matrix to be scanned, under the control of logic circuitry, such that those switch contacts associated with the keyboard keys are more frequently scanned than are those switches associated with the other inputs. Information for controlling an audio tone generator is provided in digital form as a function of the state of the contacts of the switches comprising the matrix, the audio frequency signals being digitally synthesized.

Abstract: A digital synthesizer primarily intended for use in electronic musical instruments which are microprocessor controlled includes a plurality of storage devices which contain numerical data commensurate with the characteristics of an output signal to be produced. Information is read out of these storage devices under the control of command signals having a predetermined repetition frequency. The generation of the command signals is controlled in such a manner as to permit the generation of harmonically related frequencies.

Abstract: The type and root of a chord played on a chromatically tuned musical instrument are determined by assigning sequential numerical values to the notes of the chromatic scale and, when a chord is played, calculating the intervals between the individual notes comprising the chord arranged in numerical order. In a preferred embodiment the smallest interval and the interval immediately following the smallest interval are compared with prerecorded interval values commensurate with all defined chord types to identify the type of chord played. The recorded information also contains a root value for each defined chord and these root values are employed, along with the starting note of the smallest interval, to determine chord root.

Abstract: The phase of digitally synthesized audio frequency signals of the same frequency is synchronized prior to conversion of the signals into analog form. The phase synchronization is accomplished, in a musical instrument of the keyboard type, by comparison of the digitally coded signals which are commensurate with all of the simultaneously generated input commands and, when frequency coincidence is detected, employing the phase value of the first of plural commanded signal at the same frequency as the starring phase value for subsequently generated signals at the common frequency.

Abstract: The invention concerns a polyphonic musical synthesizer using digital techniques. The generation of successive wave form patterns makes use of phase data for addressing a wave form memory, and of amplitude and harmonic or octave row data contained in a set of memory blocks. Control of the synthesizer is effected by externally addressing the memory set in order to write the aforementioned data in it.The development of synthesis operations within the synthesizer is conditioned by a sequential chain of reading of the different memory blocks in terms of signals from a plurality of generators.

Abstract: A polyphonic digital synthesizer which will generate a plurality of periodic signals in real time with independent control of amplitudes. A set of digital memories are at least equal in number to the periodic signals to be produced, the address of each memory determining the frequency of a signal and the content of said memory determining at least the amplitude of said signal. Digital to analog conversion means produce positive or negative analog voltage or current steps whose amplitude is proportional to a data item read in a memory and in response to control signals. These reading and transfer of the data from the memories to the conversion means and conversion control signals are provided in accordance with the transitions of pulsed signals whose repetition frequencies are distributed over a predetermined musical range. Complex output signals can be obtained by writing data in the memories according to an additive synthesis method.

Abstract: A polyphonic electronic musical instrument in which the complex signal delivered by the instrument is made up of successive samples.Each sample in the complex signal is the sum of the samples of the different harmonics of the various notes played, at the corresponding amplitudes. A device for scanning the keys and pedals comprises two or three counters which operate in association with one another to detect the number (i) of each played note out of the 12 or 13 notes in an octave, and also detect the number of the corresponding octave (n) and successively calculate the various samples of the harmonics of the note (i, n). The set of operations is performed in a sufficiently short time to produce notes of 6- 10 kHz.