OLED Display White Sub-Pixel Defect Repair via Laser and Color Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing OLED display manufacturing processes are prone to defects due to complex active driving pixel circuits and dust generation, leading to reduced yield and display quality issues, especially when bright spot defects occur in red, green, or blue sub-pixels, which cannot be replaced by other sub-pixels.
Innovation Solution
The OLED display device incorporates a white sub-pixel with second red, green, and blue filters, allowing for compensation and restoration by adjusting gray scales during RGB to RGBW conversion, and using laser to create dark spots for defect repair, while maintaining display quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If laser is used to cut off TFT connection lines to form dark spots for defect repair, then bright spot defects are eliminated, but too many dark spots affect display effect and reduce product rating
Solution Approach 1:
The patent converts the harmful effect of bright spot defects into a beneficial repair mechanism by using the white sub-pixel to compensate for defective color sub-pixels. Instead of simply creating dark spots that mask defects, the system actively compensates by adjusting the white sub-pixel's emission to replace the missing color information, thereby maintaining display quality while repairing defects.
Solution Approach 2:
The patent changes the operational parameters of the white sub-pixel by adjusting its emission intensity and color temperature to compensate for defective color sub-pixels. By dynamically modifying the white sub-pixel's output parameters during display operation, the system achieves defect repair without creating visible dark spots, thus maintaining overall display quality.
2Adaptability or versatility
If complex active driving pixel circuits are used in OLED devices, then full-color display capability is achieved, but manufacturing defects increase due to complexity and dust generation
Solution Approach 1:
The patent makes the white sub-pixel serve multiple functions: it acts as a normal white display element during regular operation and simultaneously serves as a compensation mechanism for defective color sub-pixels. This multi-functionality allows the system to maintain full-color display capability while providing built-in defect repair, thereby improving production yield without sacrificing display versatility.
Solution Approach 2:
The patent incorporates the white sub-pixel and its associated light filters into the display structure in advance, creating a built-in compensation mechanism before defects occur. This beforehand cushioning ensures that when manufacturing defects happen, the system already has the necessary components (white sub-pixel and color filters) in place to compensate for failures, thereby protecting against yield loss.
3Reliability
If gray scale conversion from RGB to RGBW is performed with coefficient multiplication, then white sub-pixel compensation is optimized, but color accuracy may be affected
Solution Approach 1:
The patent implements a feedback mechanism in the gray scale conversion process where the output from defective color sub-pixels is monitored and compensated by adjusting the white sub-pixel's emission. The coefficient multiplication during RGB to RGBW conversion is dynamically adjusted based on the detected defect conditions, ensuring that color accuracy is maintained while achieving effective defect compensation through continuous optimization.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables effective repair of bright spot defects in any sub-pixel by utilizing the white sub-pixel's filters for color compensation, maintaining display quality and extending the lifespan of OLED devices.
Implementation Method 1
a fourth OLED device and a second red filter, a second green filter and a second blue filter located on a light outgoing side of the fourth OLED device
Implementation Method 2
the white sub-pixel includes a fourth OLED device and a second red filter, a second green filter and a second blue filter located on a light outgoing side of the fourth OLED device
Implementation Method 3
irradiating a region of the white sub-pixel except the light filter with a same color as that of the one of the red sub-pixel, the green sub-pixel and the blue sub-pixel to make an irradiated region of the fourth OLED device deteriorate and not emit light anymore
Data Source
AI summary
An OLED display device and a repair method thereof are disclosed. The OLED display device includes a pixel, wherein the pixel includes a red sub-pixel, a green sub-pixel, a blue sub-pixel and a white sub-pixel; the red sub-pixel includes a first OLED device and a first red filter located on a light outgoing side of the first OLED device; the green sub-pixel includes a second OLED device and a first green filter located on a light outgoing side of the second OLED device; the blue sub-pixel includes a third OLED device and a first blue filter located on a light outgoing side of the third OLED device; and the white sub-pixel includes a fourth OLED device and a second red filter, a second green filter and a second blue filter located on a light outgoing side of the fourth OLED device.