OLED Gamma Voltage Adjustment for Damage Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic light emitting diode (OLED) display devices suffer damage due to inconsistent gamma reference voltage adjustments based on image brightness, leading to either excessive peak or minimum brightness generation.
Innovation Solution
An OLED display device with a brightness detector, adder, average value calculator, gamma weight calculator, and gamma reference voltage generator that calculates and adjusts gamma reference voltage step-by-step according to average brightness values, using a look-up table to determine appropriate voltage weights for increased or decreased gamma reference voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If gamma reference voltage is adjusted based on image brightness, then display quality is improved, but device damage occurs due to excessive peak or minimum brightness generation
Solution Approach 1:
The patent applies dynamics by making the gamma reference voltage adjustable rather than fixed. The voltage is dynamically modified based on the average brightness of the current frame through a gamma reference voltage modifier, allowing the system to adapt to different display conditions and prevent extreme brightness values that could damage the OLED.
Solution Approach 2:
The patent implements feedback by detecting the average brightness of the current frame and using this information to adjust the gamma reference voltage. The brightness detector continuously monitors display output and feeds this information back to the voltage modifier, creating a closed-loop control system that prevents excessive peak or minimum brightness generation.
2Device complexity
If gamma reference voltage is kept constant, then device operation is simple, but brightness inconsistency occurs under different image conditions
Solution Approach 1:
The system transitions from a static gamma reference voltage to a dynamic one that changes based on frame brightness. The gamma reference voltage modifier adjusts the voltage level according to detected brightness conditions, ensuring consistent display quality across different image content while maintaining relatively simple circuit architecture.
3Illumination intensity
If peak brightness is increased to improve visibility, then display performance is enhanced, but OLED and driving transistor suffer damage
Solution Approach 1:
The patent applies preliminary anti-action by preemptively adjusting the gamma reference voltage to prevent excessive peak brightness before it occurs. The brightness detector identifies high brightness conditions in the current frame, and the voltage modifier proactively reduces the gamma reference voltage to counteract potential over-brightness, thereby protecting the OLED and driving transistor from damage.
Solution Approach 2:
Through continuous brightness monitoring and feedback-based voltage adjustment, the system detects when peak brightness may become excessive and automatically compensates by modifying the gamma reference voltage, preventing device damage before it occurs.
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 reduces damage to OLEDs and driving transistors by dynamically adjusting gamma reference voltage in response to image brightness, ensuring optimal operation and extending device lifespan.
Implementation Method 1
an electron and a hole which are supplied from the electron transport layer and the hole transport layer are re-combined to generate a light in the organic light emitting layer
Data Source
AI summary
An organic light emitting diode display device for changing a gamma reference voltage step by step in accordance with an image brightness of a current frame to reduce damage with which the organic light emitting diode and the driving transistor thereof are applied is disclosed. In the organic light emitting diode display device, a brightness detector calculates a maximum brightness value of each pixel using inputted image data of current frame. An adder adds all maximum brightness values of each pixel which are detected by the brightness detector. An average value calculator calculates an average brightness value of a current frame using an added value of maximum brightness values which are added by the adder. A gamma weight calculator calculates a gamma reference voltage weight which is set to correspond to the calculated average brightness value among predetermined gamma reference voltage weights. And a gamma reference voltage generator changes a gamma reference voltage step by step in accordance with a gamma reference voltage weight which is calculated by the gamma weight calculator.