Pixel Initialization Voltage Control for Display Brightness Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display devices face issues with non-uniform brightness due to noise in signal or voltage applied to driving transistors, affecting the luminance of light emitting elements and resulting in inconsistent image brightness.
Innovation Solution
Incorporating an initialization transistor that provides a specific initialization voltage to the driving transistor, with varying voltage levels in different modes to maintain uniform brightness, and utilizing a combination of transistors and capacitors to control the driving current and emission signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the initialization transistor is turned on during the blank period in low-frequency driving mode, then the initialization voltage is applied to the driving transistor, but the initialization transistor may be abnormally turned on due to noise, causing non-uniform brightness
Solution Approach 1:
The patent applies parameter changes by adjusting the initialization voltage level dynamically based on driving frequency. In low-frequency driving mode during blank periods, the initialization voltage level is increased to prevent abnormal turn-on of the initialization transistor. This parameter adjustment ensures that the transistor operates reliably without causing brightness non-uniformity, directly resolving the contradiction between operational stability and display uniformity.
2Reliability
If the initialization voltage level is increased in low-frequency driving mode blank period, then the initialization transistor remains normally off, but the voltage level must be differentiated from high-frequency mode
Solution Approach 1:
The patent implements dynamics by making the initialization voltage level adaptive rather than static. The voltage level automatically adjusts based on the driving frequency and timing conditions - it is increased specifically during blank periods in low-frequency mode, while maintaining standard levels in high-frequency mode and active periods. This dynamic adjustment mechanism achieves reliable transistor control without requiring complex additional circuitry, as the changes are implemented through control signal timing and level management.
3Reliability
If noise is present in the signal or voltage applied to the driving transistor, then the luminance of the light emitting element changes, but the image brightness becomes non-uniform
Solution Approach 1:
The patent applies preliminary anti-action by proactively adjusting the initialization voltage level before noise can cause abnormal transistor activation. During blank periods in low-frequency driving mode, the initialization voltage is set to a higher level in advance, creating a voltage margin that prevents noise from causing unintended turn-on of the initialization transistor. This preemptive measure eliminates the root cause of brightness non-uniformity before it can occur, rather than attempting to correct it afterward.
Data Source
AI summary
A pixel includes a light emitting element, a driving transistor configured to control a driving current provided to the light emitting element, and an initialization transistor configured to provide a first initialization voltage to a gate of the driving transistor, and turned on in response to an initialization gate signal. A voltage level of the first initialization voltage in a blank period of a low-frequency driving mode is higher than a voltage level of the first initialization voltage in the blank period of a high-frequency driving mode.