Abstract: A mechanical supercharger utilized in internal combustion engines includes a housing having an inlet port, outlet port and a bypass passage disposed in the housing for connecting the inlet port and the outlet port with each other. A relief valve is disposed in the bypass passage for releasing an air pressure from the outlet port to the inlet port.

Abstract: A supercharged pressure controller for internal combustion engines, which comprises a switch valve for switching negative pressure at a throttle valve to atmospheric pressure and a relief valve operated by the signal from the switch valve to release the supercharged pressure in a surge tank, thereby controlling the supercharged pressure accurately in accordance with various running conditions of vehicle, avoiding inconveniences such as rough idling or knocking of engine.

Abstract: A Roots type blower wherein a secondary gap distance for rotor is determined in accordance with a cross angle between a normal line at a point of the outer periphery of theoretical base curve of the rotor and a line extending through said point and the rotor center.

Abstract: In the present invention, a timing pulley is moved to a start point position in which a start point switch is switched on or off by a pulse motor, the start point position is memorized in a memory of a control circuit, key codes of selected pattern selection switches are calculated, a driving step number of the pulse motor is calculated by cam position data of a selected pattern obtained by the key codes, the cam position data being previously memorized in a memory, and position data of pattern cam selected in the present time, the position data being memorized in a random access memory and a cam-follower is moved to the position of the selected pattern cam by driving the pulse motor.

Abstract: A three-keyboard electronic musical instrument of the type generating binary-coded primary key data representative of notes played on the keyboards, and secondary key data representative of unplayed notes that are correlated with the played notes in some musically favorable way. Prior to introduction into a multi-channel tone generator circuit, part of the primary key data and all of the secondary key data are directed into a key data memory having storage channels corresponding in number to the sounding channels in the tone generator circuit available for such data. A discrimination data memory has a plurality of storage locations, corresponding to the storage channels of the key data memory, for storing binary-coded data representing the discrimination between the primary and the secondary key data stored on the corresponding storage channels of the key data memory.

Abstract: A polyphonic, keyboard-type electronic musical instrument capable of automatic production, in response to key depressions on upper and lower keyboards, of "fill notes" which bear the same note names as the depressed lower keys but which, preferably, fall within an octave below the lowest pressed upper key at every moment. The instrument is of the type wherein each depressed key is coded into key data in accordance with a binary "key code" composed of a note code and an octave code. The note code identifies the note name of each key, whereas the octave code identifies the octave to which the key belongs. Upon depression of a key on each of the upper and lower keyboards, the note-coded data derived from the key date representative of the depressed lower key are combined with the octave-coded data derived from the key data representative of the depressed upper key if the note name of the depressed lower key is below that of the depressed upper key.

Abstract: An electronic musical instrument with an automatic chord performance device is of a type in which chord tones of plural series of different tone colors in different rhythm patterns are produced. This instrument employs a memory for storing a plurality of patterns per one rhythm and for plural rhythms in order to simultaneously obtain the chord tones of plural series per one rhythm. The patterns are read from the memory as tone generation timing signals. These tone generation timing signals control the amplitudes of the envelopes of the chord tone signals. The chord tone signals thus controlled in amplitude are generated after being controlled in the tone color in each of the series.

Abstract: In a digital type electronic musical instrument, a glide effect is produced by digitally frequency-modulating the frequency of a musical tone in such a manner that the frequency changes quickly and smoothly. Glide information used for effecting this frequency-modulation is produced on the basis of a glide code obtained by counting a clock pulse. The glide information which changes its contents uniformly is multiplied with the basic frequency information to effect the frequency-modulation. The glide effect can be controlled for each individual keyboard. According to an embodiment of the invention, the frequency-modulation is applied to an attack portion of a musical tone only and sustain and decay portions of the musical tone are reproduced with a normal frequency so that the musical tone will be provided with a crisp, vivid musical effect.

Abstract: The invention is directed to a waveshape generator capable of producing a desired waveshape by previously storing basic amplitudes obtained by sampling one period of the waveshape at a coarse interval and calculating amplitudes with a fine interval between the basic amplitudes. While basic amplitudes A and B are sequentially produced at a coarse interval in response to an integer portion of the input data, a function X (c) is produced in response to a fraction portion of the input data. Waveshape amplitudes are interpolated between the basic amplitudes by carrying out calculation of A + (B - A) .times. X(c) in response to these values A, B and X(c). A special form of function X(c) is also used for applying interpolation by a partial waveshape of a trigonometric function wave. An example of a musical tone waveshape generator is also described in which different waveshapes are produced depending upon different tone ranges by moving the position of a radix point for each of the different tone ranges.

Abstract: This key switch system (1) scans closed (or open) key switches in a matrix to produce corresponding key data, (2) encodes these key data into corresponding key codes, and (3) effectively registers the encoded key codes into time-shared channels of a key code memory.The key switch system may be incorporated in an electronic musical instrument. The system includes a key data generator which produces block data consisting of one pulse per scanning cycle in a time slot representing a block to which a key switch which is ON belongs, and note data consisting of a pulse in a time slot representing the particular key switch which is ON in the block indicated by the block data. A key coder encodes the block data and note data supplied from the data generator into key codes each representing the key name of the depressed key. A channel processor allots the key codes to storage channels of a key code memory having a number of such channels equal to the maximum number of tones to be reproduced simultaneously.

Abstract: In a digital type electronic musical instrument in which basic frequency information corresponding to a depressed key is cumulatively counted and a musical tone waveshape is read from a memory by the resultant output of the cumulative counting, a musical tone including a coarse noise is produced by randomly frequency-modulating the basic frequency of the musical tone, thereby providing the tone with a random vibrato effect. The frequency-modulation is effected by randomly adding or subtracting information expressed in the form of a certain frequency difference relative to the basic frequency information to or from the basic frequency information. According to an embodiment of the invention, a noise effect is produced only during a rise portion of the musical tone by reducing noise component in steps from the start of depression of a key and reproducing a musical tone of a normal pitch after a lapse of a predetermined period of time.

Abstract: In a digital type electronic musical instrument in which frequency information corresponding to a depressed key is cumulatively counted and a musical tone waveshape is read from a memory by the resultant output of the cumulative counting, modified frequency information is produced by adding to or subtracting from said frequency information second frequency information represented by a predetermined frequency difference. A tone of a pitch which is slightly different from a normal pitch is generated from this modified frequency information for producing a beat effect between notes in an octave relation. The pitch can be controlled by suitably adjusting the second frequency information. Different beat effects can be produced for respective keyboards by varying the second frequency information by each keyboard.

Abstract: In a digital type electronic musical instrument in which basic frequency is cumulatively counted and a musical tone waveshape is read from a memory by the resultant output of the cumulative counting, a desired vibrato effect is produced by digitally frequency-modulating the basic frequency. Vibrato information for effecting the frequency-modulation is produced from a vibrato code obtained by counting a clock pulse and a vibrato depth signal and has contents which change as time elapses. The frequency-modulation is made by multiplying the basic frequency with the vibrato information. The vibrato depth may be controlled for each individual keyboard. Vibrato frequency may be changed by changing the frequency of the clock pulse for each keyboard. According to an embodiment of the invention, the vibrato depth progressively increases from the start of reproduction of the musical tone. The speed of change of the vibrato depth may also be controlled for each individual keyboard.