Yamaha Corporation

Shigeaki Sato

Shigeru Muramatsu

Tadaharu Kato

Nobuo Sugiyama

Kiyoshi Kawamura

Satoshi Inoue

Hajime Hayashida

Takashi Aoyagi

Ringi Nozue

Atsushi Matsumura

An electronic grand piano comprises a plurality of keys arranged on a keybed, a plurality of actions interlocked with the keys, and an electric circuit unit for performing tone-generation operations based on operations of the actions when the keys are operated. A pair of slide portions, each having an elongated shape, are arranged in parallel and are fixed to outer peripheries of the electric circuit unit. A pair of guide portions are arranged in parallel with respect to a main body of the piano and are loosely engaged with the slide portions. When the electric circuit unit is moved in a prescribed direction relative to the main body, it is automatically stopped and fixed at a prescribed position by means of a fixing structure.

Keyboard musical instrument structure

An optical position transducer is provided for each of the black/white keys incorporated in a composite keyboard musical instrument; the optical position transducer includes a photo-coupler radiating a light beam, an optical filter moved across the light beam, a recess formed in the black/white key at a proper position where the optical filter is aligned with a target trajectory crossing the light beam and an elastic coupler pressed to an inner surface defining the recess and secured to the optical filter so that a worker assembles the optical filter with the key by inserting the elastic coupler into the recess.

Keyboard musical instrument having easily installable optical position transducer with coupler for coupling optical modulator to moving object

Easily installable optical position transducer and keyboard musical instrument having the same

A key depression detection apparatus is constituted by a sensor case incorporating key sensors, which can be easily adjusted in positions relative to an arrangement of keys on a keyboard frame (or a keybed) in a keyboard instrument such as a piano. The sensor case has a case body incorporating a key sensor and is affixed to a base member that is fixed to the keyboard frame by using a fixing member, which is constituted by a lower member and a pair of upper members. The legs of the case body are securely held by the fixing member between the lower member and upper members, which are connected together using screws accompanied with springs. Thus, an operator can easily adjust the sensor case in position relative to an arrangement of keys by manually controlling screws.

Key depression detection apparatus for keyboard instrument

A composite keyboard musical instrument includes an acoustic grand piano, an electronic sound generating system and a silent system, and an electric motor, a hammer stopper, a link work and a controller form in combination the silent system, wherein rigid arms and rigid rods are assembled into the link work so as to promptly transmit the force from the actuator to the hammer stopper without substantial time lug.

Keyboard musical instrument equipped with hammer stopper promptly driven for rotation by means of rigid link work

A grand piano has a split top board, i.e., plural sub-boards selectively opened by a pianist for emphasizing higher registered sounds or lower registered sounds and a visual display, which teaches the pianist how to tune the grand piano in the desired mode for selectively emphasizing the higher/lower registered sounds.

Keyboard musical instrument having split rear top board and/or visual display unit

An acoustic upright piano, an electronic sound system and a hammer stopper form in combination a keyboard musical instrument for generating acoustic sounds in an acoustic sound mode and electronic sounds in an electronic sound mode, and the hammer stopper has a rotatable shaft extending in a lower space under damper blocks of damper assemblies, cushion members projecting into an upper space over the damper blocks and connecting brackets provided between the rotatable shaft and the cushion members, thereby perfectly interrupting hammer motions before an impact on strings in the electronic sound mode.

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Hamamatsu, Japan

Shigeaki Sato