OLED Gamma Voltage Controller for Brightness Stability
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Solution Overview
Problem
Conventional organic light emitting display devices face issues with voltage drop across pixels, leading to inconsistent brightness and display quality due to variations in the first power supply voltage, and external factors affecting reference power supplies can further deteriorate image quality.
Innovation Solution
An organic light emitting display device with a gamma voltage controller that compares the reference power voltage with a comparative power voltage, compensating for voltage variations by adjusting gamma voltages to maintain consistent brightness, using a scan driver, data driver, and pixel circuit configured to receive reference, first, and second power supplies, and an analog-digital converter to convert voltage differences into digital signals for control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a reference power supply is used to compensate for voltage drop, then brightness consistency is improved, but display quality deteriorates when reference power voltage changes due to external effects
Solution Approach 1:
The patent dynamically adjusts the gamma voltage parameter based on the detected voltage difference between reference power and first power supply. The gamma voltage controller modifies the gamma voltage signal according to the magnitude and direction of the voltage difference, thereby compensating for voltage variations and maintaining consistent brightness while adapting to external environmental effects.
Solution Approach 2:
The patent implements a feedback mechanism where the voltage difference between reference power and first power supply is continuously detected and fed back to the gamma voltage controller. This feedback loop enables real-time adjustment of gamma voltage to compensate for voltage drops and maintain display quality under varying operating conditions.
2Stability of the object's composition
If voltage drop compensation is implemented, then brightness consistency is improved, but device complexity increases
Solution Approach 1:
The gamma voltage controller serves multiple functions: it generates gamma voltage signals for display operation, detects voltage differences between power supplies, and dynamically adjusts gamma voltage for compensation. By combining these functions into a single controller, the patent reduces overall device complexity while maintaining brightness consistency.
Solution Approach 2:
The patent merges the voltage detection function and gamma voltage adjustment function into an integrated control system. The gamma voltage controller combines the tasks of generating display signals and compensating for voltage drops, thereby simplifying the circuit architecture while achieving the desired brightness consistency.
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 ensures that images are displayed with desired brightness levels, regardless of voltage changes in the reference power supply, thereby improving overall display quality by compensating for voltage drops and external environmental effects.
Implementation Method 1
The organic light emitting display device displays an image using organic light emitting diodes that emit light by a re-combination of electrons and holes
Data Source
AI summary
An organic light emitting display device includes a scan driver for driving scan lines and light emitting control lines; a data driver for selecting any one gamma voltage of a plurality of gamma voltages corresponding to bit values of externally supplied data and generating data signals; a pixel coupled to a reference power, a first power, and a second power, and the pixel configured to compensate for a voltage drop of the first power using the reference power; and a gamma voltage controller for comparing a voltage value of the reference power with that of a comparative power having a target voltage value of the reference power to generate a comparison result and controlling voltage value of the gamma voltages in accordance with the comparison result.