Pixel Threshold Compensation Layout for Uniform Display Luminance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display apparatuses face challenges in maintaining uniform display quality due to variations in threshold voltages of driving transistors along the transmission direction of driving voltage, leading to luminance non-uniformity and inefficiencies in pixel performance.
Innovation Solution
The display apparatus incorporates a design with a data line, a driving voltage line, and pixels arranged adjacent to each other, where the threshold voltages of driving transistors gradually increase along the transmission direction, utilizing a P-channel transistor with a semiconductor layer, first and second gate electrodes, and a floating second gate electrode to adjust and compensate threshold voltages, thereby minimizing voltage-current curve shifts and charge storage decreases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pixels are arranged adjacent to each other in the first direction connected to the data line and driving voltage line, then the display apparatus can achieve compact layout and high pixel density, but the threshold voltages of driving transistors gradually change along the transmission direction causing luminance non-uniformity
Solution Approach 1:
The patent applies local quality by configuring different pixel circuits at different positions along the driving voltage line. Specifically, pixels closer to the driving voltage line source have different threshold voltage compensation mechanisms compared to pixels farther away. This is achieved by varying the capacitor connections and transistor configurations in each pixel circuit to compensate for the cumulative voltage drop along the line, thereby maintaining uniform luminance across all pixels despite their different electrical environments.
2Device complexity
If a simple pixel circuit configuration is used to reduce device complexity, then manufacturing and operation become easier, but threshold voltage variations cause Long Range Uniformity issues
Solution Approach 1:
The patent employs parameter changes by dynamically adjusting the threshold voltage of driving transistors through capacitor-based compensation circuits. Each pixel circuit includes capacitors that store compensation voltages to offset threshold voltage shifts in the driving transistors. The compensation amount varies based on the pixel's position along the driving voltage line, with pixels experiencing greater voltage drops receiving larger compensation. This parameter adjustment mechanism maintains display uniformity without requiring fundamentally complex circuit topologies.
Solution Approach 2:
The patent implements feedback through threshold voltage compensation circuits that continuously monitor and correct for voltage drops along the driving voltage line. The capacitor networks in each pixel circuit provide feedback by storing and applying compensation voltages that counteract the cumulative effect of line resistance. This feedback mechanism ensures that pixels at different positions receive appropriate threshold voltage adjustments, maintaining uniform display performance across the entire display area.
Data Source
AI summary
Provided is a display apparatus including: a data line extending in a first direction; a driving voltage line extending in the first direction; and a plurality of pixels connected to the data line and the driving voltage line and arranged adjacent to each other in the first direction, wherein threshold voltages of driving transistors of the plurality of pixels arranged along the first direction gradually changing.