Tiled Display Pixel Circuit With Sensing Feedback for Luminance Uniformity
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Solution Overview
Problem
Tiled display devices face challenges in achieving uniformity of pixels due to dispersion of circuit elements in the current path, leading to variations in luminance across sub-pixels.
Innovation Solution
The display device incorporates a sensing transistor connected between a first electrode of the light emitting element and a second data line, with a gate electrode connected to a sensing line, to compensate for circuit element dispersion by adjusting data signals, ensuring uniform luminance across sub-pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a tiled display device uses a plurality of display devices to enlarge the display area, then the display area is increased, but uniformity of pixels deteriorates due to dispersion of circuit elements in the current path
Solution Approach 1:
The patent introduces a sensing transistor connected between the first electrode of the light emitting element and the second data line, with its gate electrode connected to a sensing line. This sensing transistor measures the voltage at the first electrode, providing feedback information about the actual voltage received by the light emitting element. Based on this feedback, the system compensates for voltage drops caused by circuit element dispersion, thereby maintaining pixel uniformity across the enlarged tiled display area.
2Area of stationary object
If circuit elements are dispersed in the current path to supply current to light emitting elements, then the display area can be enlarged, but luminance uniformity across sub-pixels deteriorates
Solution Approach 1:
The sensing transistor measures the actual voltage at the first electrode of the light emitting element through the sensing line. This feedback mechanism allows the system to detect voltage variations caused by circuit element dispersion and compensate for them, ensuring that each sub-pixel receives the appropriate voltage to maintain uniform luminance across the entire enlarged display area.
Solution Approach 2:
The patent adjusts the voltage parameters supplied to different sub-pixels based on the measured voltage drops. By changing the data signal voltage levels compensatorily, the system ensures that each light emitting element receives the correct voltage to produce uniform luminance, despite the dispersion of circuit elements in the extended current paths of the tiled display.
3Manufacturing precision
If a sensing transistor is added to compensate for circuit element dispersion, then luminance uniformity is improved, but device complexity increases
Solution Approach 1:
The sensing transistor is integrated into the existing pixel circuit structure, sharing the same first electrode connection point as the light emitting element. The sensing line is routed through existing circuit layers, allowing the sensing function to be added without requiring completely separate circuit paths. This multi-functional integration minimizes the increase in device complexity while achieving luminance uniformity compensation.
Data Source
AI summary
A display device includes first sub-pixels, each of the first sub-pixels including a first light emitting element of a first color, and at least one of the first sub-pixels includes a first circuit unit configured to control a supply period of a driving current in response to a first data signal supplied from a first data line, a second circuit unit configured to supply the driving current to the first light emitting element in response to a second data signal supplied from a second data line, and a sensing transistor connected between a first electrode of the first light emitting element and the second data line, and having a gate electrode connected to a sensing line.