LED Display Data Driving for Defective Pixel and Crack Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display devices, such as LED displays, face challenges with enlarging beyond certain sizes, require separate repair processes for defective LEDs and pixels, and need additional equipment for crack detection, complicating the driving process and increasing complexity.
Innovation Solution
A data driving device and method that includes a line of second driving voltage, a voltage regulator, and an analog-to-digital converter to supply and sense output current, allowing for detection of defective pixels and panel cracks without additional repair or optical equipment, and enabling the use of a hybrid driving scheme combining PAM and PWM.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate repair processes are used for defective LEDs and pixels, then defective pixels can be repaired, but the driving process becomes complicated and device complexity increases
Solution Approach 1:
The patent combines the defective pixel repair function with the normal display driving function into a single integrated system. The data driving device incorporates both display driving circuits and repair driving circuits that can operate the same pixel circuits, eliminating the need for separate repair equipment and simplifying the overall system architecture.
Solution Approach 2:
The data driving device is designed to perform multiple functions: normal display driving and defective pixel repair. By making the driving device universal, it can handle both operational modes using the same hardware resources, reducing device complexity while maintaining repair capability.
2Difficulty of detecting and measuring
If separate crack detection equipment is used, then panel cracks can be detected, but device complexity increases
Solution Approach 1:
The data driving device is designed to perform multiple functions: normal display driving, defective pixel repair, and panel crack detection. By making the driving device universal, it can handle all three functions using the same hardware resources, eliminating the need for separate optical detection equipment and reducing overall device complexity.
Solution Approach 2:
The patent merges crack detection functionality with the display driving functionality. The same data driving device that controls pixel operation also performs crack detection by monitoring panel characteristics during driving, consolidating multiple functions into a single integrated system.
3Ease of operation
If PAM scheme is used to supply analog voltage corresponding to grayscale value, then current control is achieved, but low grayscale implementation becomes difficult
Solution Approach 1:
The patent changes the control parameter from analog voltage amplitude (PAM) to pulse width timing (PWM). By using PWM, the grayscale value is represented by the duration of the pulse rather than its amplitude, enabling precise low grayscale control through temporal modulation instead of amplitude modulation, which resolves the limitation of PAM in achieving low grayscale levels.
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
Enables the use of display panels with defective LEDs and pixels without separate repair, detects cracks efficiently, and reduces the need for additional equipment, simplifying the driving process and enhancing panel flexibility.
Implementation Method 1
an analog-to-digital converter configured to receive an output current of the pixel circuit through the line of the second driving voltage
Data Source
AI summary
In the embodiment, the location of the defective pixel can be determined by measuring the operating current of each LED of the pixel, and the sub-LED can be driven in response to the location information of the defective pixel, thereby implementing normal LED operation even in a pixel defect situation.