Keyboard Device Key Stopper Noise Suppression
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Solution Overview
Problem
Conventional keyboard devices for keyboard instruments face issues with noise generation during key return and inconsistent touch feeling between white and black keys due to inadequate stopper designs and shared hammer mechanisms.
Innovation Solution
The keyboard device incorporates a key stopper system with protrusions on the keys and elastic stoppers on the chassis to progressively reduce kinetic energy upon key return, and a stopper rail with adjustable portions for white and black keys to optimize touch feeling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a soft cushion is used as the upper limit stopper to suppress noise, then noise generation is reduced, but upper limit positions of keys fail to be aligned and hammer arms bounce
Solution Approach 1:
The stopper is divided into a hard stopper portion and a soft cushion portion. The hard stopper portion ensures precise alignment of key upper limit positions, while the soft cushion portion suppresses noise during key return. This segmentation allows each portion to fulfill its specific function without compromise.
Solution Approach 2:
Different portions of the stopper have different material properties: the stopper portion is made of hard material for precise positioning, while the cushion portion is made of soft material for noise suppression. This local quality differentiation resolves the contradiction between alignment precision and noise reduction.
2Ease of manufacture
If the same hammers are used for white and black keys, then manufacturing is simplified, but touch feeling cannot be optimized for both key types
Solution Approach 1:
The cushion portion is configured with different heights for white keys and black keys. White key-associated cushions have a first height, while black key-associated cushions have a second height different from the first. This allows optimization of touch feeling for each key type while using otherwise identical hammer components.
Solution Approach 2:
The height parameter of the cushion portion is varied between white keys and black keys to optimize touch feeling for each key type, while maintaining uniformity in other hammer parameters for ease of manufacture.
3Manufacturing precision
If the stopper portion is made hard for precise positioning, then key alignment is improved, but noise generation increases during key return
Solution Approach 1:
The stopper is segmented into a hard stopper portion for precise positioning and a soft cushion portion for noise suppression. This allows the hard portion to ensure accurate key alignment while the soft cushion portion absorbs impact energy quietly during key return.
Solution Approach 2:
The stopper combines hard material (for precision positioning) and soft cushion material (for noise suppression) into a single integrated component, achieving both precise key alignment and quiet operation.
Data Source
AI summary
A keyboard device for a keyboard instrument includes a keyboard chassis, keys disposed on the keyboard chassis, and a key support mechanism which is provided so as to support the keys from below, and causes, upon depression of a 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. The keyboard chassis includes a key stopper with which a rear end of an associated key moves into contact from below when the key returns to its original position before the key depression. The key includes a contact surface for contacting the key stopper in a key-released state, and a protrusion formed to protrude upward from the contact surface. At least one of the key stopper and the protrusion is disposed in plurality along a longitudinal direction of the key.