A keyboard device for a keyboard instrument includes a keyboard chassis, a plurality of keys arranged side by side in an upper portion of the keyboard chassis, and a plurality of hammers provided in association with the plurality of keys, respectively. Each hammer is pivotally supported, below an associated key, via a hammer support shaft on the keyboard chassis, and is pivotally moves in a manner interlocked with depression of the associated key. For a predetermined first hammer, which is associated with a predetermined first key of the plurality of keys, and a predetermined second hammer, which is associated with a predetermined second key of the plurality of keys, respective angles of pivotal movement, caused by key depression, of the first hammer and the second hammer are set to be different from each other.

A keyboard device for a keyboard instrument includes a keyboard chassis having a plurality of partition walls, a plurality of keys, and a plurality of hammers pivotally moved along with key depression. Let-off members are removably mounted on one of each adjacent two of the partition walls and one of the hammers disposed between the adjacent two partition walls. Engagement portions are provided on the other of each adjacent two of the partition walls and the one of the hammers disposed between the adjacent two partition walls. The engagement portions are temporarily engaged with the let-off members during pivotal movement of the hammer along with depression of a key, to thereby add let-off feeling to touch feeling of the depressed key.

A key for a keyboard device includes a resin key body and one or a plurality of woody boards attached along at least part of a side surface of the key body. The key body includes an upper convex part which extends along an upper end of the side surface and is formed continuous with on upper surface of the key body such that it protrudes in a lateral direction of the key body, and a lower supporting protrusion which is disposed in the vicinity of a central portion or a lower end of the side surface such that it protrudes in a lateral direction of the key body and is opposed to the upper convex part. The woody board is sandwiched by the upper convex part and the lower supporting protrusion.

A keyboard chassis has an upper limit stopper. A key extending a predetermined length in a front-rear direction is disposed on the keyboard chassis. A key support mechanism supports the key from below, and causes, upon depression of the key, the depressed key to operate such that the key pivotally moves about a virtual pivot located rearward of a rear end of the key. An upper limit position regulation portion provided on a lower portion of a front end of the key regulates an upper limit position thereof by contacting the upper limit stopper from below in a key-released state. A key rear-side stopper provided on the keyboard chassis is contacted by a rear end of the depressed key from below before the upper limit position regulation portion contacts the upper limit stopper, when the key returns to its original position before key depression.

A keyboard device for a keyboard instrument includes a keyboard chassis, a key disposed on the keyboard chassis, and a key support mechanism which supports the key from below and causes the key to operate such that the key pivotally moves about a virtual pivot. One of a first arm rear-side connecting portion and a second arm front-side connecting portion includes an engagement shaft extending in a left-right direction, and the other of them includes an engagement recess which has a U shape in side view and open in one of a front direction and a rear direction and is engaged with the engagement shaft. A cushioning member in sliding contact with an inner surface of the engagement recess is mounted on the engagement shaft in a state covering an outer peripheral surface of the engagement shaft.

A rotation mechanism includes a shaft portion, a bearing portion, a protruding portion, and a stopper. The bearing portion configured to rotate with respect to a predetermined axis as a center of rotation and configured to slide relative to an outer periphery of the shaft portion. The protruding portion protrudes from the shaft portion. The stopper is integrally formed the bearing portion. The stopper faces the protruding portion. A length of the protruding portion in a direction in which the protruding portion protrudes is larger than a distance from the center of rotation to a sliding portion where the bearing portion slides relative to the outer periphery of the shaft portion.

A keyboard instrument includes a key base member, a first member which is disposed on either of a left and a right of the key base member, and a second member which is disposed on the other side of disposing the first member, and a length hb in an up-down direction of a portion of the first member which corresponds to a nearer side of a key differs from a length ha in the up-down direction of a portion of the second member which corresponds to the nearer side of the key.

A keyboard device for a keyboard instrument, capable of largely reducing noise generated when a hammer contacts a lower limit stopper during key release immediately after key depression. The keyboard device includes a keyboard chassis disposed on a keybed, keys pivotally supported on the chassis, hammers pivotally supported on the chassis below the keys and each vertically pivotally moved, an intermediate rail mounted on the chassis below a rotational shaft of the hammers and its vicinity in a state floating from the keybed, and a lower limit stopper mounted on the intermediate rail, such that each hammer is placed thereon via its placement-contact portion when in a key-released state and contacts the same from above via the placement-contact portion when pivotally moving downward in accordance with key release after being moved upward by key depression, whereby further pivotal motion of the hammer is stopped.

An apparatus includes a first resonant circuit including a first coil mounted to a movable member; a second resonant circuit including a second coil facing the first coil and generating a magnetic field upon supply of an electric current and outputs a detection signal of a voltage level depending on a relative position of the second coil to a position of the first coil; and a first equivalent circuit equivalent to the second resonant circuit in a case where a distance between the first and second coils is infinite and a second equivalent circuit equivalent to the second resonant circuit in a case where the distance is zero. A processor corrects the detection signal based on an output signal output from the first equivalent circuit and an output signal output from the second equivalent circuit, and calculates, based on the corrected detection signal, a displacement amount of the movable member.

An electronic portable keyboard instrument includes: a lower casing that includes a plurality of supporting members that support the fulcrums of a plurality of hammers, and a plurality of reinforcing members arranged in the first direction, each reinforcing member having a shape of rib that is erected upward from the lower casing and that is running in a length direction of the keys, wherein each of the plurality of supporting members sandwiches, from sides in the first direction, the corresponding hammer at the fulcrum so as to restrict movement of the hammer in the first direction, and wherein each of the reinforcing members is disposed in a gap between adjacent hammers, and a portion of the reinforcing members that corresponds to the weights of the adjacent hammers in position is lower than any other portions of the reinforcing member to avoid contacting the weights of the adjacent hammers.