Abstract: A rhythm tone source assigning apparatus for use in an electronic musical instrument comprises a memory having a plurality of storing regions corresponding to a plurality of input operating manipulators each being comprised of a keyboard key or a switch. Arrangement is provided so that by writing a tone source identifying datum corresponding to desired one of a plurality of rhythm tone sources in one of the storing regions corresponding to an input operating manipulator one after another, rhythm tone sources can be assigned to the plurality of input operating manipulators. Thus, this electronic musical instrument greatly facilitates its user of his performing or inputting operations in a hand percussion or a rhythm sequence programming by using these manipulators. That is, for each rhythm, the user is able to obtain his favorite convenient arrangement of operating manipulators.

Abstract: Data for each sample point amplitude values of a desired waveshape is expressed in mantissa and exponent in accordance with a floating-point representation. The desired waveshape is divided into a plurality of frames along a time axis and the exponent data is common in each individual one of said frames which includes a plurality of sample points. The number of the frames is much smaller than the number of all sample points. In this waveshape memory, the mantissa data corresponding to the respective sample points are stored in a first memory, and exponent data corresponding to the respective frames are stored in a second memory.

Abstract: In formation of a fibrous bearing bush for holding center pins on a piano action, synthetic resin of low saturated moisture content or is contained for stabler holding of the center pins under different environmental conditions and presence of lubricative resin on the center pin contact side assures small rolling contact with the center pin.

Abstract: A clock signal reproducing circuit for a player reproducing information of a disc reproduces a clock signal from a signal reproduced from a disc via a pickup head.

Abstract: An electronic drum has a drum body, a drumhead, a support/tension mechanism, a closed space forming member, a vibrating plate, and a piezoelectric element. The closed space forming member forms a closed air space together with the drumhead lower surface. The vibrating plate is fitted to the closed space forming member so as to divide the closed air space into plural closed air spaces. One of the divided plural closed air spaces existing between the lower surface of the drumhead and the vibrating plate serves as a transmission space. When the drumhead is struck, the vibration of the struck drumhead is transmitted to the vibrating plate via the transmission space. By this transmission via air space, same vibration at the vibrating plate is obtained irrespective of the struck portion of the drumhead if struck by same striking force. The piezoelectric element converts a pressure produced based on a mechanical vibration of the vibrating plate to an electrical signal.

Abstract: A keyboard switch apparatus for an electronic musical instrument has first and second switches each constituted by stationary and movable contacts. The stationary contacts of the first and second switches are formed adjacent to each other on a single board. The movable contacts of the first and second switches are mounted on a single flexible member arranged above the single board and are normally spaced apart from the stationary contacts at positions opposite thereto. The flexible member and the movable contacts of the first and second switches are integrally formed to have a uniform cross-sectional shape along one direction. The flexible member is deformed in response to the depression of a key. The stationary contacts corresponding to the movable contacts of the first and second switches are closed with a time difference according to a speed of key depression.

Abstract: A disc case is constructed for receiving releasably a disc on which information data are recorded and for supporting the disc rotatably in the disc case, and can be set into a reproducing apparatus with the disc received in the disc case. The disc case comprises: a first case member having a disc receiving area on its central portion; a second case member associated with the first case member to be able to open and close the disc receiving area; and locking means having first and second locking members, a first locking member being formed integrally on one of the first and second case members and a second locking member being formed integrally on the other of the first and second case members and locks the first and second case members in a closed state with the disc receiving area closed in cooperation with the first locking member. The second locking member has an opening button which elastically deforms the second locking member and release the locking of the first and second case members when operated.

Abstract: In construction of a clad material for ornamental use such as eyeglass frames and watch bands, use of age-hardenable alloy sheath followed by age-hardening enables production of product with light weight, high mechanical strength, excellent workability and good fit to brazing and plating.

Abstract: A video display processor (VDP) for use with a central processing unit, a video RAM (VRAM) and a video display unit is capable of writing video image data supplied from an external video device such as a television set into the VRAM. The VDP comprises a first input terminal for receiving the external video image data and a second input terminal for receiving horizontal and vertical synchronization signals from the external video device. The VDP generates address data in accordance with the horizontal and vertical synchronization signals and supplies the address data to the VRAM when processing of the external video image data is designated. The VDP also supplies the received external video image data to the VRAM thereby to write the external video image data into addresses of the VRAM designated by the address data.

Abstract: An electronic musical instrument with a keyboard has a musical instrument housing with the keyboard and an operation panel arranged adjacent to the keyboard, and a cover for covering the keyboard and the operation panel. Guide projections are formed at two sides of the keyboard and the operation panel of the musical instrument housing. The cover has first and second cover bodies, a first coupling device for coupling the first and second cover bodies in a foldable manner, and a second coupling device for pivotally coupling a rear end portion of the first cover body with the musical instrument housing. The front end portion of the second cover body is guided and slid along the guide projections when the cover is opened or closed. When the cover is open, the outer surface of the second cover body stands facing forward and serves as a music rack.

Abstract: In a musical tone synthesizer in which an amplitude-modulated carrier wave delivered from an amplitude modulator is used to form a musical tone signal, the amplitude-modulated carrier wave is fed back to the input side of the amplitude modulator as a modulation signal, a portion thereof, a portion of a carrier wave or a composite signal of the modulation signal and the carrier wave. The amount of feedback may be controlled by multiplying the amplitude-modulated carrier wave with a predetermined modulation index. Furthermore, the modulation index may be charged with time so that the control of spectrum construction of the musical tone signal is readily performed. According to a modified embodiment, a plurality of amplitude-modulators are provided which are connected in a ring form feedback loop in which the modulated outputs of preceding amplitude modulators are supplied respectively to succeeding amplitude modulators.

Abstract: A pedal keyboard for an electronic musical instrument, includes a pedal key vertically pivotal about a pivot mechanism mounted on a frame of a housing for the electronic musical instrument, a spring for biasing the pedal key so as to cause the pedal key to return to an initial position, and a stopper for limiting pivotal movement of the pedal key. The spring is arranged behind the pivot mechanism of the pedal key, and the stopper is arranged behind the spring, thereby improving key depression feeling and forming a gap in the pivot mechanism to achieve smooth pivotal movement of the key.

Abstract: A device for forming a stereophonic sound field in a simulated fashion constructed in the form of a monophonic-to-stereophonic conversion circuit in which a monophonic signal is applied to cascade-connected twin-T circuits having different null point frequencies and an output signal of the twin-T circuits is provided as one stereophonic channel signal whereas an output obtained by substracting the one stereophonic channel signal from the monophonic signal is provided as the other stereophonic channel signal. A low-frequency signal attenuating resistor and a high-frequency signal attenuating filter are provided on the output side of the twin-T circuits to equalize peak values in frequency characteristics of the output signal of the twin-T circuits and thus obtained signal is amplified to be equalized in peak level to the monophonic signal and thereafter is applied to a subtractor together with the monophonic signal.

Abstract: A tuning apparatus for a stringed musical instrument includes a bridge base, a plurality of bridges, a plurality of anchor members of the same number as that of the bridges, and tuning bolts of the same number as that of the bridges or anchor members. The bridge base is fixed on a body. Each bridge is mounted on an upper surface of a front end portion of the bridge base and is movable along vertical and back-and-forth directions with respect to the body. Each bridge supports one end portion of a string at a top surface thereof. Each anchor member is mounted on an upper surface of a rear end portion of the bridge base and is movable along the back-and-forth direction. Each anchor member locks a bead coupled to one end of the string. Each tuning bolt is rotated to move the corresponding anchor member along the back-and-forth direction.

Abstract: In construction of a FRP sound bar preferably by lamination for percussive musical instruments, 30 to 80% by volume of reinforcing fibers are oriented in a resin matrix at least in the longitudinal direction of the sound bar and a plurality of longitudinal pores are almost uniformly distributed over the entire cross section of the sound bar, for easy and low cost production with ideal sound extension.

Abstract: An electronic musical instrument comprises a plurality of keyboards each having a plurality of keys, a control circuit for controlling a manner of tone production, and a musical tone production circuit responsive to respective depressed keys of respective keyboards. The control circuit controls the musical tone production circuit in response to operation of a switch mounted on a control panel for manually selecting one of a plurality of sets of preset parameters corresponding to a kind of a musical tone to be performed. The musical tone production circuit modifies a tone specified by a depressed key in any keyboard according to the selected switch on the control panel.

Abstract: In production of a golf club head by heat pressing of a compound in a splittable mould, the compound of a fixed weight is injected into the mould cavity through an injection tube which is clamped by the mould and removed after appreciable hardening of the compound. Provision of an asylum for extra bulk of compound by the injection tube remarkably reduces production of undesirable dregs or flash at heat pressing. The injection tube also serves to define the correct positioning of a core used in the product.

Abstract: A stereo demodulator capable of demodulating a composite signal without performing a switching operation is disclosed. A subcarrier generating circuit generates a square wave subcarrier signal V1 of 38 KHz which is in turn converted into a triangular wave subcarrier signal V4 of 38 KHz synchronized with the square wave subcarrier signal V1. The composite signal is converted into a current signal i which is then amplified by a voltage-controlled amplifier whose gain varies in accordance with the triangular wave subcarrier signal V4 applied thereto as a control voltage. Since the voltage-controlled amplifier is of such a type that the gain thereof logarithmically varies in accordance with the control voltage, the composite signal is amplified by a gain which varies substantially sinusoidally in accordance with the triangular wave subcarrier signal V4. As an output of the voltage-controlled amplifier is in the form of a pair of currents i.sub.R and i.sub.