Organic EL Display Row Luminance Uniformity Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display devices using organic electroluminescent elements exhibit uneven luminance due to fabrication process variations, leading to streaky image quality and degradation in luminance uniformity, requiring a method to adjust luminance characteristics in units of rows.
Innovation Solution
A display device comprising a scan circuit, signal output circuit, and display elements arranged in a two-dimensional matrix, with a driving method that controls the crest value of scanning signals applied to each scan line to adjust the luminance characteristics of display elements, allowing for uniformity in image display.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a standard driving method is used for organic EL display elements, then the display device can be manufactured with conventional processes, but luminance uniformity deteriorates due to fabrication process variations causing streaky image quality
Solution Approach 1:
The patent applies local quality by making the scanning signal characteristics (crest value) different for each scan line based on the specific luminance characteristics of that row. This allows each row to be individually optimized to compensate for fabrication variations, improving luminance uniformity without changing the overall manufacturing process complexity.
Solution Approach 2:
The patent changes the parameter of the scanning signal (crest value) to adjust the luminance characteristics of each row. By varying the crest value of scanning signals applied to different scan lines, the invention compensates for mobility and threshold voltage variations in transistors, thereby improving luminance uniformity across the display.
2Manufacturing precision
If row-specific luminance adjustment is implemented, then luminance uniformity is improved, but the driving method becomes more complex
Solution Approach 1:
The patent achieves luminance uniformity by simply changing the crest value parameter of existing scanning signals for each row, rather than introducing entirely new circuitry or complex control mechanisms. This approach improves luminance uniformity while minimizing the increase in driving method complexity.
Data Source
AI summary
A driving method for a display device includes the steps of: performing writing processing to apply a video signal to a first node over a data line via a writing transistor with a predetermined driving voltage applied from a power supply to one of source/drain regions of a driving transistor, wherein the trailing edge of a scanning signal to be applied to a gate electrode of the writing transistor at the writing processing step is inclined; and the luminance characteristic of display elements connected onto each of a scan lines is controlled by controlling the crest value of the scanning signal, which is applied to first to M-th scan lines, for each of the scan lines.