Gamma Reference Voltage Setting for OLED Display Devices
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Solution Overview
Problem
Current methods for controlling image generation in organic light emitting displays degrade image quality and reliability due to the assumption that all devices have the same gamma characteristics, leading to suboptimal gamma reference voltage settings.
Innovation Solution
A method and device for setting a gamma reference voltage by measuring luminance and adjusting a temporary value incrementally until the desired luminance is achieved, allowing for individual optimization of gamma reference voltage for each organic light emitting display device, and setting a transistor voltage by adding a margin value to the optimized gamma reference voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed gamma reference voltage is used for all devices, then the control process is simple, but image quality and reliability degrade due to variations in gamma characteristics
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the gamma reference voltage based on measured luminance values. Instead of using a fixed voltage, the system measures the actual luminance at a given gamma reference voltage and adjusts the voltage parameter to achieve the target luminance, thereby adapting to device variations while maintaining simple control architecture
Solution Approach 2:
The patent implements feedback by measuring the actual luminance output at a given gamma reference voltage and using this measurement to determine whether to adjust the voltage. The system compares measured luminance with target luminance and adjusts the gamma reference voltage accordingly, creating a closed-loop control that ensures consistent image quality across devices with different gamma characteristics
2Reliability
If gamma reference voltage is adjusted for each device, then image quality improves, but the control process becomes more complex
Solution Approach 1:
The patent applies self-service by enabling each display device to automatically measure its own luminance characteristics and self-adjust its gamma reference voltage without external intervention. The device performs self-diagnosis and self-optimization by measuring luminance at different voltage levels and autonomously determining the optimal voltage, thereby improving image quality while avoiding complex external control systems
Solution Approach 2:
The patent implements preliminary action by performing voltage adjustment and luminance measurement during the manufacturing or initialization phase before normal operation. The system pre-determines the optimal gamma reference voltage for each device through preliminary testing and stores this information, so that during actual use, the device simply needs to retrieve and apply the pre-optimized voltage, avoiding complex real-time control
3Reliability
If incremental adjustment of gamma reference voltage is performed, then optimal voltage is found, but measurement time increases
Solution Approach 1:
The patent applies partial action by performing incremental adjustments of the gamma reference voltage rather than exhaustive searching through all possible voltage values. The system adjusts the voltage in controlled steps (e.g., 0.1V increments) and stops when the target luminance is achieved or a predetermined number of iterations is reached, thereby finding sufficiently optimal voltage without the time cost of complete exhaustive search
Solution Approach 2:
The patent implements skipping by making larger voltage jumps when the measured luminance is far from the target value, and reducing step sizes only when approaching the target. This rushed-through approach allows the system to quickly eliminate obviously incorrect voltage values and focus measurement time only on the narrow range where optimal performance occurs, significantly reducing total measurement time while maintaining optimization quality
Data Source
AI summary
An organic light emitting display device includes a gamma reference voltage setter to set a gamma reference voltage, a gamma reference voltage generator to generate a gamma reference voltage set by the gamma reference voltage setter, and a gamma voltage generator to generate a gamma voltage based on the gamma reference voltage. The gamma reference voltage setter sets the gamma reference voltage to a first temporary value, increases the first temporary value by a first delta value, searches a second temporary value at which luminance of the display panel is less than a preset value, and sets the gamma reference voltage based on the searched second temporary value.