Touch Panel Boundary Channel Inspection Using Capacitance Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Touch electrodes in touch panels may become shorted or open, leading to inaccurate detection of touch inputs, which is a common issue in electronic devices with touch panels, particularly in mobile devices like smartphones and tablets.
Innovation Solution
A method of inspecting a touch panel by determining correction capacitances and channel gaps based on mutual capacitances, using a touch panel inspector to identify and correct open or shorted boundary line channels, thereby ensuring precise touch input detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional inspection methods are used for touch panels, then the inspection process is simple, but open defects in boundary line channels cannot be accurately detected
Solution Approach 1:
The patent applies preliminary action by determining correction capacitances and channel gaps before performing the actual inspection of boundary line channels. The inspection device pre-calculates correction capacitances for all touch channels based on mutual capacitance values, and pre-determines channel gaps between adjacent touch channels. This preliminary preparation enables accurate detection of open defects during the inspection phase without adding complexity to the core detection mechanism.
Solution Approach 2:
The patent uses correction capacitance as an intermediary parameter to bridge the gap between raw mutual capacitance measurements and accurate open defect detection. By introducing correction capacitance values that account for channel gap variations, the system mediates between the imperfect raw measurements and the desired accurate detection results, enabling precise identification of open defects in boundary line channels.
2Measurement precision
If correction capacitances are determined for all touch channels, then detection accuracy is improved, but calculation time and processing complexity increase
Solution Approach 1:
The patent applies local quality by focusing correction capacitance determination and channel gap calculation specifically on boundary line channels, which are most prone to open defects. While correction capacitances are calculated for all touch channels, the critical inspection and analysis are concentrated on boundary line channels. This localized approach ensures high detection accuracy where needed most while minimizing unnecessary processing time for internal channels that have lower risk.
3Reliability
If channel gaps are determined based on correction capacitances, then open defects in boundary line channels are accurately detected, but the inspection process becomes more complex
Solution Approach 1:
The inspection device performs preliminary determination of channel gaps between adjacent touch channels before conducting the actual open defect inspection of boundary line channels. By pre-calculating and storing channel gap values based on correction capacitances, the device prepares reference data that simplifies the subsequent inspection process. This preliminary action reduces the complexity of the main inspection task by having reference values ready for comparison.
Solution Approach 2:
The patent implements feedback by using determined channel gaps as reference values to evaluate and interpret the inspection results of boundary line channels. The system continuously compares measured capacitance values against the pre-determined channel gap references, and uses this feedback to accurately identify open defects. This feedback mechanism enhances reliability by providing a baseline for comparison while maintaining a systematic inspection process.
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
This method minimizes defects in boundary line channels by accurately determining channel gaps, enhancing the reliability of touch input detection in touch panels.
Implementation Method 1
determining first correction capacitances based on mutual capacitances of a first test boundary line channel of a test touch panel and a candidate correction coefficient
Data Source
AI summary
An inspection method including: determining first test correction capacitances using mutual capacitances of a first test boundary line channel of a test panel and a candidate coefficient; determining second test correction capacitances using mutual capacitances of a second test boundary line channel of the test panel and the candidate coefficient; determining test channel gaps of the first test boundary line channel using the first and second test correction capacitances; determining reference channel gaps based on mutual capacitances of a test non-boundary line channel; determining the candidate coefficient as a correction coefficient based on the reference and test channel gaps; determining first correction capacitances of a first boundary line channel of the touch panel; determining second correction capacitances of the second boundary line channel of the touch panel; determining channel gaps of the first boundary line channel using the first and second correction capacitances; and inspecting the first boundary line channel.