Display Driver Fault Detection via Voltage Comparison
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Solution Overview
Problem
Interconnections in display modules, including those between display drivers and panels, often experience faults such as shorts and opens, which are difficult to detect effectively with existing testing methods.
Innovation Solution
A display driver system comprising a decoder, a source amplifier, and logic circuitry that outputs grayscale voltages and generates fault detection data by comparing reference voltages with actual voltages on external output terminals, allowing for the detection of faults in source lines and COF interconnections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing testing methods are used for display module interconnections, then the testing process is simple, but fault detection accuracy is poor
Solution Approach 1:
The testing system is segmented into distinct functional modules: a display driver IC containing test signal generation circuitry, a display panel with test signal transmission lines, and a testing device with voltage measurement capabilities. This segmentation allows each module to be optimized for its specific function while maintaining overall system effectiveness in detecting interconnection faults.
Solution Approach 2:
A test signal is introduced as an intermediary element to facilitate fault detection. The test signal is generated by the display driver IC, transmitted through the display panel interconnections, and measured by the testing device. This intermediary test signal enables indirect observation of interconnection integrity without requiring direct access to all connection points.
2Reliability
If comprehensive fault detection is implemented, then reliability of display module improves, but testing time increases
Solution Approach 1:
Fault detection is performed as a preliminary action during the manufacturing process before the display module is assembled and shipped. The testing device measures voltages at specific timing points during the operation of the display driver IC, enabling early detection of interconnection faults that would otherwise remain undetected until field failure.
Solution Approach 2:
The testing method utilizes periodic sampling of voltage signals at specific timing points during the display driver IC operation. By measuring voltages at strategically selected moments in the periodic waveform, the system achieves comprehensive fault detection with minimal measurement time, avoiding the need for continuous monitoring.
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 reliable detection of faults in display module interconnections, improving the manufacturing and quality control processes by accurately identifying short and open faults during the panel charging, high impedance, and fault detection periods.
Implementation Method 1
The comparison is performed by the source amplifier... based on a comparison between a reference voltage and a voltage on the external output terminal
Data Source
AI summary
A display driver comprises a decoder, a first source amplifier and a logic circuitry. The decoder is configured to output a grayscale voltage corresponding to an image data. The first source amplifier is configured to output a first source output voltage corresponding to the grayscale voltage to a first external output terminal. The logic circuitry is configured to generate fault detection data for fault detection of a test object connected to the first external output terminal. The fault detection data is based on a comparison output signal generated based on a comparison between a reference voltage and a voltage on the first external output terminal. The comparison is performed by the first source amplifier.