Abstract: A keyboard device configured such that, when L represents a distance in a horizontal direction from a rotation support of a hammer member 3 to a contact point where a key 2 comes into contact with an elastic section 23 of the hammer member 3, I represents a moment of inertia around the rotation support, and K represents an elastic modulus in a vertical direction of the elastic section 23 coming into contact with the key 2, the relationship of L, I and K is set to (2/?)2·K·10?4?(I/L2)?4·(2/?)2·K·10?4. Accordingly, when the key 2 is depressed, a timing at which an action load applied to the key 2 by the hammer member 3 reaches its maximum is delayed by 10-20 milliseconds from the start of the depression, whereby the maximum action load can be applied at a timing that gives a key-touch feel close to that of an acoustic piano.

Abstract: A keyboard device configured such that, when L represents a distance in a horizontal direction from a rotation support of a hammer member 3 to a contact point where a key 2 comes into contact with an elastic section 23 of the hammer member 3, I represents a moment of inertia around the rotation support, and K represents an elastic modulus in a vertical direction of the elastic section 23 coming into contact with the key 2, the relationship of L, I and K is set to (2/?)2·K·10-4(I/L2)4·(2/?)2·K·10-4. Accordingly, when the key 2 is depressed, a timing at which an action load applied to the key 2 by the hammer member 3 reaches its maximum is delayed by 10-20 milliseconds from the start of the depression, whereby the maximum action load can be applied at a timing that gives a key-touch feel close to that of an acoustic piano.

Abstract: A keyboard, having a plurality of keys arranged so as to be pivotable upward and downward and a plurality of light emitters arranged under the keys in one-to-one correspondence therewith, selectively causes the light emitters to emit light, thereby teaching keys to be depressed. A base resin, which forms each of the plurality of keys, has transparency and contains a pigment which colors the base resin and a light scattering agent having a light diffusion property. By virtue of the use of the pigment and the light scattering agent, a surface color which confers a refined feature on the keys can be realized, and accordingly a product with an excellent appearance can be attained. Moreover, by virtue of the blending of the pigment and the light scattering agent, the keys can shine uniformly without a difference in brightness when their corresponding light emitters are lighted, and a keyboard instrument player can fully recognize by his/her eyes that the keys shine.

Abstract: An improved key device for an electronic keyboard musical instrument of the type having a fulcrum and a chassis each mounted on a support, and having a key pivotably mounted on the fulcrum, is further provided with a rotor rotatably coupled to the chassis. A first end of the rotor is in contact with an after-fulcrum rear end of the key. A key-returning spring is arranged to couple the rotor and the chassis. A rotation shaft member is fastened to the chassis, the rotor having a recessed portion for receiving the rotation shaft member whereby the rotor is rotatable relative to the rotation shaft member. A heavy mass portion is fastened to a second end of the rotor, the first and second ends of the rotor being on opposite sides of a rotational center of the rotation shaft member. A stopper is mounted on the chassis for suppressing vibrations of the rotor generated when the key is depressed.