OLED Display Image Sticking Correction via Pixel Aging
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Solution Overview
Problem
OLED display devices suffer from image sticking due to varying gray scales causing different drain currents and voltage stress on thin film transistors, leading to threshold voltage drifts and reduced light emitting efficiency over time.
Innovation Solution
An OLED display device with a pixel detecting circuit that detects and adjusts the aging degrees of OLED pixels by displaying an aging image with brightness inversely proportional to pixel age, ensuring uniform aging across the array, and optionally using threshold voltage or voltage across the OLED to indicate aging, with a timing circuit for initiating detection and adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If different gray scales are displayed to show image content, then display brightness and contrast are improved, but threshold voltage drift of thin film transistors occurs causing image sticking
Solution Approach 1:
The patent applies preliminary action by performing uniform aging treatment on all OLED pixels before actual display operation. This pre-treatment equalizes the initial states of pixels that will experience different voltage stresses during normal operation, preventing threshold voltage drift and image sticking. The aging process is conducted by displaying a specific test image with known luminance values across all pixels for a predetermined time period.
Solution Approach 2:
The patent implements feedback by measuring the actual luminance output of each OLED pixel after aging treatment and using this information to adjust subsequent display operations. The system compares measured luminance values against expected values and compensates for deviations, ensuring uniform display performance despite varying aging characteristics of individual pixels or groups of pixels.
2Manufacturing precision
If OLED pixels are aged uniformly to correct image sticking, then display uniformity is improved, but additional time and processing steps are required
Solution Approach 1:
The patent applies partial action by dividing the OLED pixel array into multiple groups and performing aging treatment on each group separately rather than attempting to age all pixels simultaneously or individually. This grouping strategy reduces the overall aging time while still achieving uniformity across the entire display. The system ages a first group of pixels, then a second group, and so on, which is more time-efficient than comprehensive uniform aging of all pixels at once.
3Reliability
If aging treatment is performed on all OLED pixels, then image sticking is corrected, but device complexity and processing steps increase
Solution Approach 1:
The patent applies segmentation by dividing the OLED pixel array into multiple distinct groups for sequential aging treatment. Each group can be aged independently using the same aging image and process parameters, which simplifies the overall control logic compared to attempting to age all pixels simultaneously with different parameters. The segmentation approach maintains reliability by ensuring each group receives adequate aging treatment while reducing system complexity through standardized group-level processing.
Data Source
AI summary
The embodiments of the present invention provide an OLED display device and a method for correcting image sticking of an OLED display device. The OLED display device comprises an OLED pixel array; a pixel detecting circuit for detecting aging degrees of respective OLED pixels in the OLED pixel array; wherein respective OLED pixel are aged by displaying an aging image on the OLED pixel array, such that the aging degrees of respective OLED pixels are the same; the brightness of each pixel in the aging image is inversely proportional to the aging degree of the pixel. According to the OLED display device and the method provided by the embodiments of the present invention, various approaches can be applied for detecting the aging degrees of respective OLED pixels in the OLED pixel array, such that the image sticking of the OLED display device can be corrected by adjusting the aging degrees of respective OLED pixels.