Abstract: In a typical musical tone producing device of a full waveshape readout type, a full waveshape of a musical tone to be produced from the start to the end of sounding or a rise portion and a part of the waveshape following the rise portion of the musical tone is stored in a waveshape memory, and the musical tone is formed by reading out the waveshape from the waveform memory once, or reading out the rise portion once and thereafter reading out the partial waveshape repeatedly. A digital filter is introduced following the waveshape memory in this tone producing device. The filter characteristics is determined in accordance with a tone color change parameter such as the key touch or the tone pitch of the musical tone, thereby realizing a tone color change of the musical tone. Further, in order to realize timewise change of tone color of the musical tone, the circuit which has the tone color change parameter vary with time is proposed.

Abstract: An amplifier circuit including two general purpose operational amplifiers is disclosed. The output terminals of first and second operational amplifiers are connected via first and second resistors in series. A connection point between the first and second resistors is connected to an output terminal and is also connected to an inverting input terminal of the first operational amplifier via a feedback loop. Thus, the first and second operational amplifiers work as class-A amplifier, so that the crossover distortion is prevented from being generated. An input signal is inputted to a non-inverting input terminal of the first operational amplifier wherein the input signal is amplified. The amplified input signal is added with a dc bias voltage and is supplied to a non-inverting input terminal of the second operational amplifier. The output voltage of the first operational amplifier varies in a positive voltage area, and the output voltage of the second operational amplifier varies in a negative voltage area.

Abstract: The present invention provides a racket frame with a grip which includes an inner low rigidity layer embracing the rear end section of a shaft and an outer high rigidity layer embracing the inner low rigidity layer and partly in direct contact with the shaft, the direct contact being at the position of the node of the primary vibration transmitted through the shaft when striking a ball.

Abstract: There is provided a video display controller which can vertically and horizontally shift a whole video image displayed on a screen of a video display unit. The video display controller comprises an image data read circuit which reads the image data from a video RAM, a register into which data representative of amount of shift of the video image is stored by a central processing unit, and a first counter which cyclicly counts a clock signal. An adder adds the data contained in the register and a count output of the first counter, and at a timing determined by this addition result a predetermined value is preset into a second counter. This second counter counts the clock signal from the predetermined value, and the image data read by the image data read circuit is outputted to the video display unit at a timing in accordance with a count output of this second counter. The register, first counter, adder and second counter are provided in each of vertical and horizontal scanning control circuits.

Abstract: A video display processor (VDP) produces a video signal by which a black and white image of an increased gradation can be displayed on a video display unit. The VDP reads from a video RAM (VRAM) either color codes each representative of a color of each display element, or amplitude data representative of amplitudes of a video signal to be reproduced. When displaying an image based on the color codes, the color codes are converted by a color palette circuit into color data each composed of three primary color data, and then supplied to a digital color encoder. The digital color encoder multiplies each of the three color data by predetermined coefficients at proper phase timings to output data representative of three chrominance signals. This output data is summed by an adder circuit and then converted into an analog signal to be supplied to the video display unit as the video signal. When displaying an image based on the amplitude data, the color palette circuit converts the amplitude data into gradation data.

Abstract: In an optical sensor for displacement speed/displacement of a movable element in a musical instrument, light emitted from a light-emitting element is guided to a sensor head through a transmission optical fiber and is further guided to a light-receiving element through a reception optical fiber. The sensor head is located at a position corresponding to a shutter movable in accordance with the movable element in the musical instrument. The shutter controls photocoupling and nonphotocoupling between the transmission and reception optical fibers. The sensor is of transmission or reflection type.

Abstract: A keyboard switch apparatus for an electronic musical instrument has first, second and third layers, and first and second switches. The second layer has elasticity and is separated from the first layer. The third layer has elasticity and is inserted between the first and second layers at a distance therefrom. The first switch consists of conductors respectively formed on opposite surfaces of the second and third layers. The second switch consists of conductors respectively formed on opposite surfaces of the first and third layers. The second and third layers are sequentially urged and deformed by an actuator interlocked with key depression. The first and second switches are sequentially closed. A time requred for closing the first switch is different from that for closing the second switch. The closure time difference corresponds to a key depression speed, which is used to generate a signal corresponding to the depression speed, and a musical tone signal corresponding to the depression speed.

Abstract: An electronic musical instrument comprises: a keyboard circuit for generating a pitch data signal which designates the note name of a musical tone to be produced; a speech signal generator for generating a speech signal which tells in human voice the name of the designated musical tone; multiplexed processing circuit for time-divisionally processing the pitch data signal and the speech signal; and sound signal producing circuit for producing the musical tone and the human voice in accordance with the processed output from the multipled processing circuit. Thus the instrument speaks the names of the tones as it produces the musical tones.

Abstract: In a reverberation tone generating apparatus a digital memory device is used as a delay element. Amplitude data obtained by sampling an input musical tone at a predetermined period are sequentially stored in the digital memory device. The readout of the amplitude data stored before a desired delay time is equal to the readout of the data regarding the input musical tone delayed the desired delay time. By imparting the desired reverberation characteristics to the delayed amplitude data, reverberation tone of the input musical tone is produced. In a modified embodiment, an input musical tone is divided into a plurality of frequency bands and different reverberation characteristics are added to the divided input musical tones respectively.

Abstract: A video display control system for displaying a video image on a screen of a video display unit. This video display control system basically comprises a VRAM (video RAM) and a video display processor (VDP). The VRAM has memory locations corresponding to display elements on the screen. The VDP includes a first register for receiving area information identifying a display area on the screen, an address generator for generating addresses of memory locations corresponding to the display area in accordance with the area information, and a memory accessing circuit for accessing the memory locations having the addresses. Therefore, the memory accessing operation through this VDP does not need a complicated support by a central processing unit. The VDP further comprises a second register for storing a color code supplied from an external device or read from the VRAM.

Abstract: A disc loading device in a disc playback device comprises a turntable for rotating a disc thereon, a holder which is provided above this turntable for holding a disc or a case housing a disc and is capable of moving upwardly or downwardly with respect to the turntable and a carrier which is capable of moving horizontally with respect to the holder for loading the disc or the case into the holder or ejecting it from the holder. A cam is provided in the holder which cooperates with a hole formed in the carrier to move the holder upwardly or downwardly in loading and ejection of the disc or the case. A clamper may be provided on the holder for fixing the disc to the turntable.

Abstract: In a disc playback device of a type in which a turntable is connected to a disc motor shaft, a device for preventing vibration of the disc motor shaft comprises magnetic biasing means for generating a magnetic force biasing the disc motor shaft in an axial or radial direction of the shaft. The magnetic biasing means is constructed by securing one of magnetic substance and a magnet to the turntable and disposing the other below the turntable or securing one of two magnets to the turntable and disposing the other magnet below the turntable. For preventing vibration of the disc motor shaft in the radial direction, a yoke plate is fixed to the magnet in such a manner that a part of the yoke plate is positioned on the lateral side of the magnetic substance or the other magnet.

Abstract: In a disc playback device of a type in which a turntable is connected to a disc motor shaft, a disc centering device comprises at least three disc centering members provided in the turntable substantially concentrically with the disc motor shaft and separately moveably in the radial direction of the turntable, the centering members being capable of engaging a central opening of a disc, and urging means provided in the turntable for urging the centering members radially outwardly of the turntable. The centering members engaged in the central opening of the disc work in association with the urging means to position the disc concentrically with the disc motor shaft.

Abstract: A digital-to-analog converter (DAC) converts digital input data into an analog output signal with less harmonic distortion over an entire signal-level range. An exponent value detector detects from the digital input data the number of bits by which the digital input data is to be shifted to form a mantissa part thereof. A digital shifter shifts the digital input data in accordance with the output of the exponent value detector, and outputs the mantissa part which is then supplied to a mantissa-part DAC. The mantissa-part DAC comprises an R-2R resistor ladder network and outputs the result of DA conversion of the mantissa part to an exponent-part DAC. The exponent DAC shifts the output of the mantissa-part DAC by an amount determined by the output of the exponent value detector, and outputs the shifted signal as the analog output signal of this DAC.

Abstract: A disc rotation control device for a compact disc player comprises a stable rotation detection circuit for detecting whether rotation of a compact disc is in a stable state or in an unstable state, a phase control loop for phase-controlling the disc rotation and direct control means for directly controlling the disc rotation. The disc rotation is controlled by the phase control loop when the disc rotation is in a stable state and, if the disc rotation has become unstable, the control of the disc rotation is switched to one by the direct control means. During the phase control, even if an EFM signal reproduced from a disc has become unavailable for some reason, preceding phase difference data is held and used for the disc rotation control.

Abstract: A gain-controlled amplifier amplifies an input signal at a gain which varies exponentially in accordance with a control voltage applied thereto and selectively outputs one of non-inverted and inverted output signals substantially identical in characteristic with each other. The gain-controlled amplifier comprises first and second transistor pairs, a common emittor driving circuit and a subtracting circuit. The first transistor pair comprises first and second transistors, and the second transistor pair comprises third and fourth transistors. The emittors of each of the transistor pairs are joined together, and bases of the first and third transistors and bases of second and fourth transistors are joined together, respectively. The two sets of joined bases serve as input terminals of the control voltage. The common emitter driving circuit complementalily drives each of the joined emitters in accordance with the input signal of the amplifier.

Abstract: The present invention provides a tone color control so that the tone color in an attack portion of a tone to be generated differs depending upon whether or not a slur effect is to be imparted. If, for example, the slur effect is not imparted, a tone color for an attack portion of a tone which is rich in variation is used, whereas if the slur effect is to be imparted, a stable tone color which is the same as the sustain portion of a tone is used. In another aspect of the invention, in the case of imparting the slur effect, a tone signal is distributed to two channels and envelopes of signals in the respective channels are separately and independently controlled by separate control signals. In one channel, a control signal of decay characteristics is used whereas in the other channel, a control signal of attack characteristics is used. The changing rate of the control signal of the attack characteristics is made greater than that of the control signal of the decay characteristics.

Abstract: A video data processing circuit eanbles an image to be displayed at a higher resolution on an image display unit such as a CRT display unit without the need for high speed parallel-to-serial (P/S) conversion and high speed accessing to look-up tables. Video data each composed of k bits are read in parallel from first to ith video RAMs (VRAMs) and supplied to a corresponding one of first to jth P/S converters. Each of the first to jth P/S converters parallelly stores those k bit video data. Each of the P/S converters serially outputs the stored video data one by one at a first time interval. The video data from the first P/S converters are supplied to a first look-up table, and similarly the video data from the second P/S converters to jth converters are supplied respectively to second to jth look-up tables. Each of the first to jth look-up tables convert the supplied video data into color data.

Abstract: A keyboard musical instrument with a transpositional function includes a keyboard, a mode selection switch, a microcomputer, a musical tone signal generator and a sound system. The keyboard has a plurality of keys respectively representing different notes in a musical scale. The mode selection switch selects one of a transposition mode and a play mode. The microcomputer includes a CPU, a ROM, and a RAM to detect first and second depressed keys when the transposition mode is selected by the mode selection switch. The microcomputer generates transposition data having a value corresponding to an interval between the notes represented by the first and second keys. The microcomputer generates a note signal representing a note higher or lower by the interval represented by the transposition data than a note of a given depressed key when the play mode is selected by the mode selection switch.

Abstract: An electronic stringed instrument includes strings, a plurality of metal frets, an ultrasonic transmitter/receiver, and a fret discriminator. The strings are kept taut above an instrument body. The frets are arranged below the strings along their extension direction. When a player depresses a given string to be picked, at least one of the metal frets is brought into contact with the given string. The transmitter/receiver is coupled to specified positions of the strings and causes ultrasonic vibrations of the strings and receives an echo vibration generated as a reflection of the ultrasonic vibration at a fret contacting the given string. The fret discriminator discriminates the fret contacting the string among the metal frets according to the time difference between the generation of the ultrasonic vibration and the receipt of the echo vibration by the transmitter/receiver.