OLED Display Black Mode Voltage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
OLED display devices face challenges in minimizing power consumption and luminance deviations due to characteristic deviations in driving TFTs, leading to increased battery consumption and potential image quality issues.
Innovation Solution
The OLED display device incorporates a black mode operation where a constant low or zero voltage is supplied to data lines during initialization, sampling, and programming periods, eliminating the need for alternating reference and data voltages, and uses an internal compensation pixel driving circuit to manage TFT deviations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an internal compensation pixel driving circuit is introduced to compensate TFT characteristic deviations, then luminance deviation between pixels is improved, but power consumption increases
Solution Approach 1:
The patent implements dynamic operation mode switching between normal mode and black mode based on image content. In black mode, when only black pixels are displayed, the compensation circuit is deactivated to reduce power consumption. In normal mode, the compensation circuit is activated to maintain luminance uniformity. This dynamic adaptation resolves the contradiction by applying compensation only when necessary.
Solution Approach 2:
The patent applies different driving strategies to different pixel types. Black pixels are driven in black mode without compensation, while non-black pixels are driven in normal mode with compensation. This local differentiation allows the system to reduce overall power consumption by excluding low-power black pixels from compensation operations while maintaining quality where needed.
2Measurement precision
If alternating reference voltage and data voltage are supplied to data lines during initialization and sampling periods, then TFT threshold voltage sensing accuracy is improved, but power consumption increases
Solution Approach 1:
The patent dynamically adjusts voltage supply based on operation mode. In black mode, only a single voltage level is supplied to data lines throughout all periods, eliminating the need for alternating voltages and reducing power consumption. In normal mode, alternating reference and data voltages are supplied to maintain sensing accuracy. This dynamic approach resolves the contradiction by applying precise voltage switching only when compensation is needed.
Solution Approach 2:
The patent extracts and removes the alternating voltage supply mechanism specifically for black mode operation. By identifying that black pixels do not require accurate threshold voltage sensing, the system extracts and eliminates the power-intensive voltage alternation process for these pixels, retaining it only for non-black pixels where measurement precision is critical.
3Reliability
If a compensation circuit is continuously operated to maintain image quality, then luminance deviation is reduced, but battery consumption increases
Solution Approach 1:
The patent implements dynamic operation mode switching between normal mode and black mode based on image content. In black mode, when only black pixels are displayed, the compensation circuit is deactivated to reduce power consumption. In normal mode, the compensation circuit is activated to maintain luminance uniformity. This dynamic adaptation resolves the contradiction by applying compensation only when necessary.
Solution Approach 2:
The patent employs periodic action by alternating between compensation-active periods (normal mode) and compensation-inactive periods (black mode). This periodic switching allows the system to maintain image quality stability during necessary periods while minimizing energy loss during black display periods, optimizing the balance between reliability and energy efficiency.
Data Source
AI summary
Provided is an OLED display device that is in a black mode in which a threshold voltage of a driving TFT need not accurately be sensed. Further, a low voltage value of zero or less is constantly and continuously supplied to a data line during an initialization period, a sampling period, and a programming period in a pixel. As a result, when the pixel is driven in the black mode, a reference voltage and a data voltage having different values are not alternately supplied to the data line to minimize power consumption.