Display Device Luminance Correction via Adaptive Data Voltage
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Solution Overview
Problem
Organic light emitting display devices face issues with accurate luminance when emitting mixed or single color light, as the luminance does not correspond to the desired gamma curve, and lateral leakage occurs due to current leakage through the P-doped Hole Injection Layer, leading to undesired luminance emission.
Innovation Solution
A display device and driving method that include a processor and a display panel with a data driver and observation pixels, where different data voltages are applied based on the grayscale values of adjacent pixels to correct the luminance, using a grayscale corrector to convert input grayscale values based on the number of adjacent pixels emitting different colors, ensuring accurate luminance across various color combinations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If grayscale voltages are set to exhibit luminance according to a gamma curve for white color light, then white color light emission accuracy is improved, but luminance accuracy deteriorates when mixed color light or single color light is emitted
Solution Approach 1:
The patent applies dynamics by making the data voltage adaptive rather than fixed. The grayscale corrector dynamically adjusts the data voltage based on the emission state of observation pixels, transitioning between different voltage levels (first data voltage when observation pixels emit, second data voltage when they don't). This dynamic adjustment resolves the contradiction by allowing the system to maintain luminance accuracy across different color emission scenarios while preserving the gamma curve calibration for white light.
Solution Approach 2:
The patent changes the parameter of data voltage based on the emission state of adjacent pixels. By detecting whether observation pixels are emitting light and accordingly selecting between different data voltage levels, the system adjusts the electrical parameter to compensate for lateral leakage effects. This parameter change enables accurate luminance control for both white light (maintaining gamma curve) and colored light (compensating for leakage).
2Ease of operation
If a P-doped Hole Injection Layer is used to facilitate current flow, then ease of operation is improved, but lateral leakage occurs causing undesired luminance emission
Solution Approach 1:
The patent applies preliminary anti-action by proactively compensating for the harmful lateral leakage effect before it manifests as display error. The grayscale corrector预先 detects the emission state of observation pixels and adjusts the data voltage accordingly, applying a counteracting voltage level to prevent the harmful effect of lateral leakage from degrading display accuracy. This preliminary correction maintains ease of operation with the P-doped layer while neutralizing its harmful leakage effect.
Solution Approach 2:
The patent implements feedback by using the emission state of observation pixels as feedback information to adjust the data voltage applied to the target pixel. The system continuously monitors whether adjacent pixels are emitting light and uses this feedback to dynamically select the appropriate data voltage level, thereby compensating for lateral leakage through a closed-loop control mechanism that maintains display accuracy without sacrificing the ease of current flow provided by the P-doped layer.
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 the display device emits light with desired luminance for both white and colored lights, accurately following the gamma curve, and prevents lateral leakage by adjusting data voltages, thereby improving the overall display performance.
Implementation Method 1
An organic light emitting display device includes a plurality of pixels, and allows organic light emitting diodes of the plurality of pixels to emit lights to correspond to a plurality of grayscale values constituting an image frame
Data Source
AI summary
A display device includes a processor and a display panel for receiving observation grayscale values from the processor. The display panel includes a data driver for applying data voltages to data lines, a target pixel coupled to at least one of the data lines, and observation pixels each coupled to at least one of the data lines, and located adjacent to the target pixel. The display panel applies a first data voltage to the target pixel, when the observation grayscale values for the observation pixels exceed a reference value. The display panel applies a second data voltage to the target pixel, when at least one of the observation grayscale values does not exceed the reference value. The first data voltage and the second data voltage are different from each other.