Pixel Driver Circuit Charging Speed and Precision
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pixel driver circuits struggle to efficiently charge capacitors in high-resolution display panels, leading to reduced effective display time and deteriorated display effects due to charging currents being equal to or less than target currents, which limits their application to both high and low resolution panels.
Innovation Solution
A pixel driver circuit with a charging circuit that includes a current source and a current control transistor, capable of generating a charging current greater than the target current during the charging stage, ensuring the capacitor is charged to a target voltage difference, thereby enabling faster charging and improved display performance across various resolution panels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the charging current is set equal to the target current to ensure accurate capacitor charging, then the charging precision is improved, but the charging speed becomes too slow for high-resolution display panels
Solution Approach 1:
The patent applies dynamics by making the charging current variable rather than fixed. The circuit dynamically adjusts the charging current in two stages: initially providing a large current for fast charging, then switching to a smaller current for precise final charging. This dynamic adjustment resolves the contradiction between charging speed and precision by adapting the current level to the charging progress.
Solution Approach 2:
The patent implements periodic action by dividing the charging process into distinct time periods or stages. The first period uses a large charging current for rapid voltage increase, while the second period uses a smaller current for precise voltage adjustment. This periodic switching of current levels allows the system to achieve both fast charging and high precision.
2Speed
If the charging current is increased to improve charging speed for high-resolution panels, then the charging speed is improved, but the display time period is reduced and display effect deteriorates in low-resolution panels
Solution Approach 1:
The circuit dynamically adapts the charging current based on the required precision, allowing fast charging when needed while maintaining accuracy. This dynamic approach enables the same circuit to serve both high-resolution panels (requiring fast charging) and low-resolution panels (requiring longer display time) without compromise.
Solution Approach 2:
The patent changes the charging current parameter during the charging process and across different operating conditions. By adjusting the current magnitude based on the specific panel requirements and charging stage, the system optimizes both charging speed and subsequent display time period, resolving the contradiction between these two parameters.
3Device complexity
If a simple capacitor structure is used to control driving transistor turning-on degree, then the device complexity is reduced, but the circuit cannot be applied to high-resolution display panels due to insufficient charging speed
Solution Approach 1:
The patent introduces dynamic current control into the otherwise simple capacitor structure. By adding control transistors that dynamically adjust the charging current based on voltage thresholds, the system maintains structural simplicity while achieving high charging speeds suitable for high-resolution panels.
Solution Approach 2:
The patent uses control transistors as intermediary elements between the power source and the capacitor. These intermediary devices enable precise control of the charging current without requiring a completely complex control system, thus maintaining relative simplicity while achieving the required charging performance.
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 allows for increased charging speed and reduced charging time, enabling the pixel driver circuit to be applied to high-resolution panels while prolonging display time and enhancing display effects on low-resolution panels.
Implementation Method 1
a capacitor C, a first end of which is connected to a gate electrode of the driving transistor T1, and a second end of which is connected to a source electrode of the driving transistor T1
Implementation Method 2
a charging circuit at least including a current source and configured to charge the capacitor C at a charging stage
Data Source
AI summary
A pixel driver circuit includes a driving transistor T1 connected in series to a light-emitting element, a capacitor C, a first end of which is connected to a gate electrode of T1 and a second end of which is connected to a source electrode of T1, and a charging circuit at least including a current source and configured to charge C at a charging stage. Within at least a part of time period of the charging stage, an intensity of a charging current for charging C is greater than an intensity of a target current, and after the charging stage, a voltage difference across C is equal to a target voltage difference. When the light-emitting element emits light at a preset brightness value at a light-emitting stage, the target voltage difference is a gate-to-source voltage difference of T1 and the target current is a current flowing through T1.