Display Panel Module Mobility Compensation for Luminance Uniformity
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Solution Overview
Problem
The existing methods for driving organic EL display panels face challenges in maintaining high luminance and image quality due to variations in threshold voltage and mobility characteristics of transistors, leading to issues like stripe clusters and poor uniformity, especially when increasing the signal electric potential to enhance luminance and contrast.
Innovation Solution
The proposed solution involves a self-light-emission-type display panel module with a pixel array section, signal holding capacitor, device driving transistor, and signal sampling transistor, along with specific driving sections that apply varying driving voltages and utilize a coupling effect to optimize gate-source voltage and mobility compensation time, ensuring consistent mobility compensation across different signal electric potentials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the signal electric potential is increased to enhance luminance and contrast, then luminance and contrast are improved, but transistor characteristic variations cause stripe clusters and poor uniformity
Solution Approach 1:
The patent applies preliminary action by performing mobility compensation during a no-light emission period before the light emission period begins. The device driving transistor is activated in advance to generate a driving current that compensates for threshold voltage and mobility variations, ensuring uniform display characteristics during subsequent light emission without requiring high signal electric potentials that would cause stripe clusters
Solution Approach 2:
The patent implements feedback through the mobility compensation mechanism where the device driving transistor continuously adjusts the gate-source voltage based on the actual operating conditions. The compensation current generated by the transistor feeds back to correct for variations in threshold voltage and mobility, maintaining display uniformity across different luminance levels and eliminating stripe cluster defects
2Illumination intensity
If the signal electric potential is increased to enhance luminance, then luminance is improved, but transistor characteristic variations lead to poor uniformity
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the gate-source voltage of the device driving transistor through mobility compensation. The system changes the electrical parameters (driving current, gate-source voltage) in response to transistor characteristic variations, allowing high luminance operation while maintaining uniformity by compensating for manufacturing variations in threshold voltage and mobility
3Reliability
If mobility compensation is performed, then transistor variations are reduced, but the process requires additional time and control complexity
Solution Approach 1:
The patent applies periodic action by structuring the operation into distinct phases: a no-light emission period for mobility compensation and a light emission period for display. The mobility compensation is performed periodically at the beginning of each frame, ensuring that transistor variations are compensated without interfering with the actual display output. This periodic structure allows efficient use of time while maintaining compensation effectiveness
Data Source
AI summary
Disclosed herein is a self-light-emission-type display panel module including: a pixel array section including pixel areas laid out to form a 2-dimensional matrix in a display area to serve as pixel areas each having a signal holding capacitor, a device driving transistor, and a signal sampling transistor; and a third driving section configured to provide a second control line connected to the other main electrode of the device driving transistor sequentially from time to time with the three different driving voltages.