Electronic Keyboard Velocity Control via Sensor Interval Correction

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Solution Overview

Problem

Existing electronic keyboard instruments face challenges in accurately controlling volume due to variations in the intervals between sensors, leading to errors in touch detection and sound generation, which cannot be effectively absorbed by current correction methods.

Innovation Solution

The implementation of a system with a keyboard having first and second switches for each key, a counting unit to count the time interval between switch activations, a correcting unit to adjust for variations in this interval, and a velocity conversion unit using a linear-to-log conversion table and touch conversion tables to ensure accurate velocity and volume control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a standard touch curve is used for volume control, then the conversion process is simple, but volume control accuracy deteriorates when sensor interval variations exist

Engineering Contradiction:
Improveconversion process complexityVSAvoidvolume control accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by pre-calculating and storing correction values in a correction table during the manufacturing process. The actual sensor intervals are measured and used to generate correction values that are stored in memory. During operation, these pre-prepared correction values are retrieved and applied to compensate for interval variations, eliminating the need for complex real-time calculations while maintaining high volume control accuracy.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If the obtainable range of count value varies due to attachment errors, then the system adapts to different configurations, but the count value falls outside the applicable range of the touch curve

Engineering Contradiction:
Improveadaptation to attachment variationsVSAvoidtouch curve applicability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the touch curve parameters based on the actual sensor interval measurements. The system modifies the touch curve characteristics (such as the relationship between key depression speed and volume) to match the specific instrument's sensor configuration. This ensures that the count values always fall within the applicable range of the adjusted touch curve, maintaining reliable volume control despite variations in sensor attachment.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If count values outside the touch curve range are forced to be converted, then the processing continues without interruption, but variations in sound generation due to attachment errors cannot be absorbed

Engineering Contradiction:
Improveprocessing continuityVSAvoidsound generation consistency
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies beforehand cushioning by incorporating a correction table that pre-compensates for potential count value variations. Instead of forcing conversion of out-of-range values and risking sound generation inconsistencies, the system uses the correction table to adjust count values into the valid range before they are converted. This preventive approach ensures that all conversions remain within the reliable range of the touch curve, absorbing attachment errors before they affect sound generation.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP1983510B1Electronic keyboard instrument and processing method of the same
Publication Date: 2016.06.29 KAWAI MUSICAL INSTR MFG CO LTD
  • EP1983510B1 patent drawingFigure 1
  • EP1983510B1 patent drawingFigure 2~3
  • EP1983510B1 patent drawingFigure 4~5

AI summary

An electronic keyboard instrument having a keyboard provided with a plurality of keys, a first and a second switches provided corresponding to each key of the keyboard and being sequentially turned on at a time interval corresponding to a key depression speed of the keyboard, a counting unit for counting a count value corresponding to the time interval during which the first and the second switches are sequentially turned on, a correcting unit for correcting the count value or a value corresponding to the count value based on a variation of the time interval, and a velocity conversion unit for converting the corrected value into a velocity, is provided.