Self-Luminous Display Burn-In Correction Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Self-luminous display elements, such as EL and organic EL elements, suffer from burn-in patterns due to deterioration over time, requiring external interface signals for feedback to prevent this issue, which increases circuit size and complexity.
Innovation Solution
A display device with a scanning line driving circuit, data line driving circuit, and writing capacitor that controls the luminous period of self-luminous elements based on their characteristics, using a drive transistor and characteristic capacitor to manage luminance without external interface signals, thereby preventing burn-in patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external interface signals are used for feedback to prevent burn-in patterns, then burn-in prevention is achieved, but circuit size and complexity increase
Solution Approach 1:
The patent extracts the feedback function from external interface signals and implements it internally within the display device. The detection circuit measures drive current for each pixel train, and the correction value is generated and applied internally without requiring external interface signals, thereby preventing burn-in while reducing circuit complexity and eliminating the need for external feedback interfaces
Solution Approach 2:
The display device performs self-diagnosis and self-correction by measuring its own drive current through the detection circuit. The system automatically generates correction values based on detected deterioration and applies them through the addition circuit, enabling the device to service itself without external intervention or complex external feedback interfaces
2Reliability
If drive current is measured for every pixel train with external feedback, then burn-in pattern is solved, but the number of interface signals increases
Solution Approach 1:
The patent combines the detection circuit, correction value generation, and signal addition functions into an integrated internal system. The detection circuit measures drive current, the correction value is generated based on detected deterioration, and the corrected signal is added to the original signal internally, merging multiple functions into a unified internal feedback loop that eliminates the need for separate external interface signals
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
The solution provides stable luminance across pixels without burn-in patterns, suitable for applications like digital cameras and mobile phones, eliminating fixed pattern burn-in states.
Implementation Method 1
the element has a property such that the luminance of that is proportional to a current amount flown into the self-luminous element
Data Source
AI summary
A display device includes a plurality of pixels, each of which has a drive transistor, an organic EL element and a writing capacitor, in which the drive transistor controls a luminous time period of the organic EL element by a writing signal voltage and a sweep signal so that the writing signal voltage is written into the writing capacitor independent from a characteristic variation caused by a deterioration due to the temperature and time lapse of using the organic EL element, thereby making a luminous time period long when the deterioration occurs with increase of an internal resistance of the organic EL element, and compensating a luminance degradation caused by the deterioration to solve a burn-in state of fixed pattern.