Keyboard Device Uniform Key Height via Variable Drive Lengths
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Solution Overview
Problem
Conventional keyboard devices for electronic musical instruments do not accurately replicate the appearance and key touch feeling of acoustic pianos, particularly in terms of key height and rocking movement, due to differences in key length and hammer engagement timing across pitches.
Innovation Solution
The keyboard device features adjustable key lengths and hammer positions to ensure uniform key height and rocking movement, with restricting members to synchronize the rocking range and engagement points of white and black keys, mimicking the appearance and feel of an acoustic piano.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the length from the pivot point of the key to the front end of the key is made gradually longer toward the high-pitched side, then the key touch feeling becomes similar to an acoustic piano, but the height of the front end of shorter keys becomes higher during key release state, resulting in poor appearance
Solution Approach 1:
The patent applies local quality by making the drive portion length variable according to key position. Specifically, the drive portion length is made longer for low-pitched keys and shorter for high-pitched keys, allowing each key to have optimized local characteristics for both touch feeling and appearance. This resolves the contradiction by enabling different key regions to have different drive portion lengths rather than using a uniform length for all keys.
Solution Approach 2:
The patent changes the parameter of drive portion length to resolve the contradiction. By adjusting the drive portion length parameter based on key pitch (longer for low-pitched, shorter for high-pitched), the system achieves both good key touch feeling and uniform key top surface height appearance. This parameter change allows the mechanism to adapt to different key positions while maintaining both functional and aesthetic requirements.
2Manufacturing precision
If the pivot point of the hammer is shifted backward toward the high-pitched side, then the engagement position between hammer and key is uniform, but the rocking range of the hammer becomes different depending on key length, affecting key touch feeling
Solution Approach 1:
The patent applies local quality by making the hammer pivot point position variable according to the key it serves. Instead of using a single pivot point position for all hammers, the patent positions the pivot point differently for hammers associated with different key lengths, ensuring each hammer-key interaction has optimized local characteristics for both engagement precision and rocking range.
Solution Approach 2:
The patent applies dynamics by making the hammer pivot point position adaptable rather than fixed. The pivot point position is determined based on the specific key requirements, allowing the system to dynamically adjust the hammer configuration to match the key characteristics, thereby achieving both uniform engagement and appropriate rocking range for each key.
3Ease of manufacture
If the vertical length of the drive portion is made the same for all keys, then the manufacturing is simplified, but the vertical position of the front end of operation portions becomes different, resulting in non-uniform appearance
Solution Approach 1:
The patent applies local quality by making the drive portion length variable according to key position. Instead of using a uniform drive portion length for all keys, the patent specifies different drive portion lengths for different key positions (longer for low-pitched, shorter for high-pitched), allowing each key to have locally optimized dimensions that achieve both uniform appearance and simplified manufacturing through standardized variations.
Data Source
AI summary
A keyboard device includes plural white keys, plural black keys, and plural hammers respectively engaged with the plural white and black keys. Vertical length of a drive portion for a first key and a second key are set the same, the first and second keys both being white keys, or both being black keys. Longitudinal position of hammer support portion of a first hammer engaged with the first key and longitudinal position of a hammer support portion of a second hammer engaged with the second key are set the same. Vertical positions of hammer support portions of the first and second hammers are respectively set according to a distance from a front end of an operation portion of the first key and a key support portion and a distance from a front end of an operation portion of the second key and a key support portion.