In-Cell Touch Display Panel Testing with Balanced Polarity Subframes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In-cell touch display panels face image display issues due to non-uniform common voltage signals, leading to problems like the roller shutter effect, which can result in missed product defects and erroneous inspections during testing.
Innovation Solution
A method is introduced where the number of subpixels with positive polarity is balanced with those having negative polarity in each frame period for each touch sensing electrode, ensuring common voltage signals remain at a consistent level by dividing the frame period into subframe periods and adjusting the polarity of pixel data transmission accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a color image display test is performed on the touch display panel with common voltage on touch sensing electrodes, then the display accuracy can be confirmed, but the non-uniform voltage level of the common voltage signal leads to image display problems such as roller shutter effect
Solution Approach 1:
The frame period is divided into multiple subframe periods, and the subpixels are divided into first subpixels and second subpixels. By segmenting the display into different groups with different polarity configurations, the patent achieves uniform common voltage levels across touch sensing electrodes while maintaining display accuracy for defect detection.
Solution Approach 2:
Different subpixel groups are assigned different polarity characteristics locally. The first subpixels and second subpixels have different polarity configurations, which creates local variations in voltage distribution that compensate for the non-uniformity issue at the global level, ensuring uniform common voltage signals.
2Stability of the object's composition
If the polarity of pixel data is adjusted to balance positive and negative polarity subpixels, then common voltage signals remain at consistent level, but the frame period must be divided into subframe periods requiring coordinated control
Solution Approach 1:
The frame period is segmented into first subframe periods and second subframe periods, with each subframe assigned to specific subpixel groups. This segmentation allows independent control of polarity for different subpixel groups, achieving voltage consistency while managing complexity through structured time division.
Solution Approach 2:
The patent implements periodic alternation between first subframe periods and second subframe periods. This periodic action creates a cyclic pattern of polarity switching that maintains average voltage consistency over time while allowing controlled variations within each period.
3Object-affected harmful factors
If scanning signals are turned on simultaneously to solve image display problems, then the roller shutter effect is mitigated, but the gate driver on array function cannot be detected resulting in missed product problems inspection
Solution Approach 1:
By segmenting the subpixels into first and second groups with different polarity configurations, the patent creates distinct test conditions for different portions of the display. This allows the GOA function to be detected through polarity-dependent responses while simultaneously mitigating the roller shutter effect through balanced voltage distribution.
Solution Approach 2:
The patent changes the polarity parameter of pixel data transmitted to different subpixel groups. By varying the polarity parameter in a controlled manner across different subframe periods, the system can detect GOA function responses while maintaining uniform common voltage levels to prevent roller shutter effects.
Data Source
AI summary
A method for testing a touch display panel includes: dividing a frame period of the image into a first subframe period and a second subframe period; transmitting pixel data to some subpixels corresponding to a touch sensing electrode in the first subframe period; and transmitting pixel data to the other subpixels corresponding to the touch sensing electrode in the second subframe period. The number of the subpixels receiving pixel data of positive polarity in the some subpixels subtracted by the number of the subpixels receiving pixel data of negative polarity in the some subpixels is defined as a first value, the number of the subpixels receiving pixel data of positive polarity in the other subpixels subtracted by the number of the subpixels receiving pixel data of negative polarity in the other subpixels is defined as a second value, and a sum of the first and second values is 0.