Yamaha Corporation

Tsuyoshi Sato

Shinji Kumano

Ichiro Osuga

Takamichi Masubuchi

Junichi Mishima

Keisuke Watanabe

Shunsuke Ichiki

Hirotsugu Kamiya

A pivot mechanism includes: a shaft portion; a bearing configured to contact the shaft portion and pivot about a pivot axis; and a reinforcement protruding from an outer circumferential surface of the shaft portion. The outer circumferential surface includes a first region contactable by the bearing in a range of its pivotal movement and a second region not including the first region in a region opposed to the first region via the pivot axis. The reinforcement extends from at least a portion of the second region to an outside of the bearing in a pivot-axis direction.

Pivot mechanism and keyboard apparatus including the same

A keyboard assembly for an electronic musical instrument comprises at least a plurality of keys, a key support member and a plurality of key-return springs. The key support member rotatably supports the keys; and the key-return spring is provided between the key and key support member so as to press up the key to a normal position. Mechanical parameters which affect a key scaling to key-touch responses of the keys are sizes, shapes and locations of parts of the keyboard assembly, which are set by analyzing motions of an action mechanism of an acoustic piano. For example, weight of the key is adjusted using a deadweight member so as to provide a specific key-touch response for the key. An amount of elastic resilience, made by the key-return spring, is adjusted by changing at least one location, at which one end of the key-return spring is terminated, so as to provide a specific key-touch response for the key. Viscous resistance, made by viscous material, such as grease, which is provided between a selected portion of the key and some member, such as a key guide and a support-point member, is adjusted by changing shape and/or size of that member, so as to provide a specific key-touch response for the key. The key scaling is performed by changing the key-touch response with respect to each of the keys; or the key scaling is performed by changing the key-touch response with respect to a selected division of the keyboard.

Electronic musical instrument simulating acoustic piano keytouch

A mounting construction of an elongated leaf spring deformed in an S-letter configuration and engaged at opposite ends thereof with a pair of spaced support members in a compressed condition to effect outward biasing forces acting of the support members, wherein three nodes are formed at the opposite ends and an intermediate position of the leaf spring in a longitudinal direction to form a pair of antinodes between the opposite ends and intermediate position of the leaf spring.

Leaf spring and mounting construction of the same

A keyboard apparatus has a support member and a plurality of white keys and black keys. Each of the white keys and the black keys has a fulcrum section and a driving section, and are pivotally mounted about the fulcrum section with respect to the support member. A mass body assembly, that is an action member, has a moving fulcrum, a driven section on a first side of the moving fulcrum that is driven by each of the driving sections of the white keys and the black keys, and a center of gravity that is located on a second side opposite the driven section with respect to the moving fulcrum. The distance between the driven section and the moving fulcrum of the mass body assembly for the black key is greater than the corresponding distance for the white key. The mass body assembly on the second side is formed from the same members that are commonly used for both the white keys and the black keys.

Keyboard apparatus with white keys and black keys having substantially

Keyboard assembly for electronic musical instrument

A keyboard apparatus having keys and mass members that are relatively light in weight and low in cost and yet provide a good key touch feeling that is comparable to the key touch feeling of a keyboard apparatus of an acoustic grand piano. A keyboard apparatus for an electronic musical instrument includes a support member including a first fulcrum section and a second fulcrum section. A key is movably supported about the first fulcrum section of the support member, and a mass member is movably supported on the support member and coupled to the key. The mass member has a mass concentration section made of an elongated metal bar and a resin section connected to the mass concentration section. The resin section has a pivotal fulcrum receiving section to be pivotally supported about the second fulcrum of the support member.

Keyboarding apparatus for electronic musical instrument with simplified

A keyboard apparatus for a musical instrument which includes a laterally elongated frame structure made of synthetic resin, a plurality of keys arranged in parallel on the frame structure and pivoted at their proximal ends on a rear end portion of the frame structure to be depressed at their front portions, and a laterally elongated printed circuit board mounted on the frame structure and provided thereon with a plurality of detection switches which are arranged to detect depression of the keys. In the keyboard apparatus, the frame structure is composed of a plurality of laterally spaced vertical reinforcement ribs placed in a fore-and-aft direction of the frame structure, an upper support plate integrally formed with the vertical reinforcement ribs at their upper end surfaces and extended in a lateral direction of the frame structure to be placed under the keys, a key mounting portion integrally formed on a rear end of the upper support plate to support the keys pivoted thereon, and a bottom plate integrally formed with the vertical reinforcement ribs at their front bottom surfaces to support the printed circuit board mounted thereon.

Keyboard apparatus for musical instrument

A keyboard apparatus has a first frame (support member), and a keyboard including a plurality of white keys and black keys, each of the keys having a fulcrum and movably about the fulcrum with respect to the support member. Each of the black keys has an extension section connected to one end of each of the black keys. The extension section extends under operation sections of two adjacent white keys toward the free ends of the white keys. A white key driving section is provided adjacent to a free end portion of each of the white keys. A black key driving section is provided adjacent to a free end portion of each of the extension sections. The white key driving sections and the black key driving sections are located at substantially the same distance from their respective fulcrums, and drive movable sections such as mass body assemblies (action members) or key switches that are operated in association with the corresponding white keys and the black keys.

Growing community of inventors

Hamamatsu, Japan

Tsuyoshi Sato