Photo-Sensor Touch Panel Brightness Threshold Segmentation
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Solution Overview
Problem
Existing photo-sensor touch panel detection methods are prone to inaccuracies due to irregular shadow shapes caused by users, leading to incorrect determination of the central touch position and reduced coordinate positioning accuracy.
Innovation Solution
A detecting method that defines two sensing areas based on different brightness thresholds to differentiate between shadow areas and areas shaded by a pointer, using relative distances and point counts to determine real touches, thereby distinguishing real touches from noise and accurately determining the central position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single threshold brightness is used to define the touch area, then the detection method is simple, but the accuracy of coordinate positioning deteriorates due to irregular shadow shapes
Solution Approach 1:
The patent divides the touch detection into two separate sensing areas: a first sensing area using a first threshold brightness and a second sensing area using a second threshold brightness. This segmentation allows the system to distinguish between shadow regions and actual touch regions, thereby improving coordinate positioning accuracy while maintaining reasonable detection complexity
Solution Approach 2:
The patent changes the brightness threshold parameter from a single value to multiple values (first threshold brightness and second threshold brightness). By using different threshold values for different sensing areas, the system can effectively differentiate between shadows and real touches, resolving the contradiction between simple detection and accurate positioning
2Ease of manufacture
If the central position is determined by calculating the mean value of coordinate values, then the calculation is straightforward, but the accuracy deteriorates when shadow areas have irregular shapes
Solution Approach 1:
The patent segments the coordinate calculation process by separately determining coordinate values from the first sensing area and the second sensing area. By calculating the mean value of coordinates from the second sensing area (which represents the actual touch region) rather than the entire touch area including shadows, the system maintains calculation simplicity while improving central position accuracy
Solution Approach 2:
The patent extracts the relevant coordinate information from the second sensing area, which specifically represents the shaded region caused by the pointer. By taking out only the coordinates from this refined sensing area and calculating their mean value, the system eliminates the influence of irregular shadow shapes on central position determination
3Device complexity
If only one sensing area is used, then the detection process is simple, but the ability to distinguish real touches from shadow noise deteriorates
Solution Approach 1:
The patent creates two distinct sensing areas with different threshold brightness values. The first sensing area captures a broader range including shadows, while the second sensing area with a higher threshold isolates the actual touch region. This segmentation enables reliable distinction between real touches and shadow noise
Solution Approach 2:
The patent changes the threshold brightness parameter to have two distinct values, creating a parameter-based differentiation between the first and second sensing areas. This parameter change allows the system to reliably identify real touches by comparing data points across the two sensing areas, improving touch detection reliability
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 effectively reduces the influence of shadows and light, improving the accuracy of coordinate positioning by correctly identifying real touch positions and distinguishing them from noise, ensuring precise detection even with irregular shadow shapes.
Implementation Method 1
an image frame is firstly obtained by scanning the photo-sensor touch panel; then a distribution area of data points in the image frame each having a brightness between a predetermined brightness and a first threshold brightness
Data Source
AI summary
An exemplary detecting method for a photo-sensor touch panel and a touch-sensitive electronic apparatus using the same are provided. In aforementioned method, an image frame is obtained by scanning the photo-sensor touch panel. Then, a distribution area of data points in the image frame each having a brightness between a predetermined brightness and a first threshold brightness is defined as a first sensing area, and a distribution area of data points in the image frame each having a brightness between the predetermined brightness and a second threshold brightness is defined as a second sensing area. Afterward, it is determined that whether a real touch probably/really occurred according to a relative distance between one of first data points and corresponding one of second data points. The first data points located in the first sensing area, and the second data points located in the second sensing area.