Touch Panel Height Detection Correction for Edge Accuracy
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Solution Overview
Problem
Existing touch panels suffer from low detection accuracy and overestimated height measurements when detecting indicators at the peripheral portion, due to fewer electrodes being faced by the indicator.
Innovation Solution
An input device with a touch panel and a height detection unit that corrects the detected height by summing signal intensities from a predetermined number of electrodes centered on the indicator's position, and applies a correction factor when the indicator is at the peripheral portion to account for insufficient electrode coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the indicator is located at the peripheral portion of the touch panel, then the hover operation can be performed at the edge area, but the detection accuracy in the height direction deteriorates due to fewer electrodes facing the indicator
Solution Approach 1:
The patent changes the parameter of height detection by introducing a correction value that compensates for the reduced number of electrodes at peripheral portions. The correction value is calculated based on the position of the indicator and the number of electrodes, allowing accurate height detection even when fewer electrodes are involved by adjusting the detection parameter through mathematical correction.
2Area of stationary object
If the number of electrodes facing the indicator is reduced at the peripheral portion, then the touch panel coverage is extended, but the signal intensity and detection level decrease
Solution Approach 1:
The patent implements a feedback mechanism where the detection result is corrected based on the number of electrodes involved. The correction value is calculated using feedback from the electrode count and position information, and this correction is applied to the detected height to compensate for the reduced signal intensity caused by fewer electrodes at the periphery.
3Ease of operation
If the height of the indicator is calculated based on reduced signal intensity at the peripheral portion, then the calculation can be performed, but the detected height becomes higher than the actual value
Solution Approach 1:
The patent applies preliminary anti-action by calculating a correction value in advance that counteracts the expected error from reduced electrode count. Before finalizing the height detection result, the system pre-calculates the correction based on the number of electrodes and applies it to prevent the detected height from being higher than the actual value, thus compensating for the anticipated measurement error.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively prevents the deterioration of detection accuracy in the height direction at the peripheral portion of the touch panel by correcting for the reduced number of electrodes involved in height detection, thereby improving accuracy as the indicator approaches the edge.
Implementation Method 1
a touch panel having a plurality of electrodes disposed side by side... measure a signal intensity proportional to a capacitance generated between the indicator and each of the electrodes
Data Source
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AI summary
To provide an input device (100) capable of preventing detection accuracy in the height direction at a peripheral portion of a touch panel (110) from deteriorating. An input device (100) includes a touch panel (110) having a plurality of transparent electrodes (112) and (114) disposed side by side, a hover signal generation unit (120) configured to generate a hover signal used to detect a height to an indicator located at a position away from a surface of the touch panel (110) to input the generated hover signal to the plurality of transparent electrodes (112) and (114), an XY position detection unit (140) configured to detect an X position and a Y position of the indicator based on a signal component that appears on each of the transparent electrodes (112) and (114) when the hover signal is input, and a height detection unit (150) configured to detect a height H of the indicator based on a signal component that appears on each of the transparent electrodes (112) and (114) when the hover signal is input. When detecting a height of the indicator, the height detection unit (150) performs a correction to increase a height of the indicator when the X position and the Y position of the indicator is included in a peripheral portion of the touch panel (110), compared with when a position of the indicator detected by the position detection unit is included in a non-peripheral portion.