Yamaha Corporation

Akiko Shinjo

Takashi Fujita

Takashi Kato

Hideki Ishihara

Akito Oba

An electronic keyboard instrument with a hammer action, in which a circuit board for generating electronic musical tones can be disposed at a location for easy maintenance and for effective space utilization. Front and rear bars are bridged between side plates of an instrument main body so as to extend parallel to each other in the left-right direction and reinforce the instrument main body. A hammer action mechanism having hammers for respective keys is disposed rearward of a key-depression part of a keyboard and upward of a rear end portion of the keyboard, and a board tray is bridged between the front and rear bars. The board tray and the circuit board are located upward of the hammer action mechanism.

Electronic keyboard instrument

An electronic keyboard instrument that emits sounds in both upward and downward directions from speakers solely for upward sound emission and from speakers solely for downward sound emission to realize acoustics similar to that of acoustic piano, and constitutes rear parts of resonance chambers in a speaker box by a common partition plate to prevent the speaker box from becoming complicated in construction. Woofers directed downward are disposed at a lower part of the speaker box, and squawker directed upward are disposed at an upper part of the speaker box. The internal space of the speaker box is partitioned by one horizontal partition plate into an upper space where resonance chambers for the squawkers are defined by vertical partition plates and a lower space where resonance chambers for the woofers are defined by vertical partition plates. Rear parts of the resonance chambers are constituted by the horizontal partition plate.

An electronic keyboard instrument in which the efficiency of sound emission is enhanced by preventing a soundboard portion having a large vibration amplitude from being hidden by a musical score plate to make sound emission of the soundboard to be hardly hindered by the musical score plate. A musical stand device is disposed rearward of a key-depression part of a keyboard and right above the soundboard, and has a musical score plate disposed close to and parallel to an upper surface of the soundboard when the musical score plate is in a fallen state. The soundboard is excited for sound production by transducers disposed on a lower surface of the soundboard. The transducers are disposed at positions where the transducers do not overlap, as viewed in plan, the musical score plate which is in the fallen state.

When a middle plate is to be mounted to an accommodating section surrounded by left and right and rear side plates provided on a body section in a casing structure of a grand-piano type electronic piano, the middle plate positioned in front of the accommodating section is slid rearward, so that a rear end edge portion of the middle plate is fitted into a fitting section provided on the inner surface of the rear side plate and then fixing pieces provided on the underside of the middle plate are fixed to fixation pieces provided on the accommodating section by means of bolts. Such an arrangement can reduce the number of portions to be fixed by bolts and thereby mount the middle plate with an enhanced mounting efficiency. Because the bolts do not appear on the exterior of the electronic piano, the electronic piano can have an enhanced outer appearance design.

Growing community of inventors

Hamamatsu, Japan

Akiko Shinjo