Keyboard device
AssigneeCasio Computer Co., Ltd.
InventorNorizo Kamimura
Life of this patent
Estimating the term…
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/π)2·K·10−4≦(I/L2)≦4·(2/π)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.
Claims6
A keyboard device comprising:
- a keyboard chassis;
- a key provided on the keyboard chassis in a manner to be rotatable in a vertical direction;
- a hammer member for applying an action load to the key by rotating to be displaced in response to depression of the key;
- and
- an elastic section provided in at least one of either the hammer member or the key, which is elastically deformed in response to the depression of the key;
- wherein the keyboard device is configured such that, when considered as a mechanical oscillation system model where L represents a distance in a horizontal direction from a rotation support of the hammer member to a contact point at which the key comes into contact with the hammer member, I represents a moment of inertia around the rotation support of the hammer member, and K represents an elastic modulus in a vertical direction of the elastic section in at least one of either the hammer member or the key, in an initial state in which the key has not been depressed, a relationship of the distance L in the horizontal direction, the moment of inertia I, and the elastic modulus K is set to (2/π)2·K·10−4≦(I/L2)≦4·(2/π)2·K·10−4, and a timing at which the action load applied to the key by the hammer member in response to the depression of the key reaches a maximum is delayed by a predetermined amount of time.
Dependencies are inferred from the claim text.