Source Driver Buffer Voltage Charging for Display Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing source drivers for display devices face challenges in accurately charging pixels with target voltages due to high on-resistance in amorphous silicon TFTs, leading to errors in voltage charging.
Innovation Solution
A source driver with a buffer and switching circuit that supplies the output voltage to data lines multiple times during a horizontal scanning interval, using a control signal with distinct activation intervals and a non-overlap period to minimize noise and ensure accurate voltage charging, leveraging charge sharing between parasitic and pixel capacitors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single voltage supply is used to data lines, then the circuit structure is simple, but the pixel capacitor cannot be charged accurately to target voltage due to high on-resistance
Solution Approach 1:
The patent applies periodic action by supplying voltage to data lines multiple times during one horizontal scanning interval. The switching circuit enables periodic voltage supply through first and second activation intervals, allowing the pixel capacitor to be charged accurately despite high on-resistance. This periodic voltage supply overcomes the limitation of single voltage supply while maintaining reasonable circuit complexity.
2Measurement precision
If voltage is supplied multiple times to data lines, then pixel charging accuracy is improved, but the circuit complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the voltage supply process into distinct time segments: first activation interval, non-overlap interval, and second activation interval. This temporal segmentation allows multiple voltage supplies during one horizontal scanning interval while managing circuit complexity through structured control. The switching circuit implements this segmentation by controlling when voltage is applied to different data lines.
Solution Approach 2:
The patent applies dynamics by making the voltage supply timing flexible and adjustable. The first and second activation intervals can be configured with different durations, and the non-overlap interval can be adjusted to minimize noise. This dynamic control allows optimization of pixel charging accuracy while managing circuit complexity through adaptive timing rather than fixed rigid structures.
3Speed
If activation intervals overlap, then the scanning speed is fast, but noise is produced by analog voltage supplied to another channel
Solution Approach 1:
The patent applies preliminary anti-action by introducing a non-overlap interval between the first and second activation intervals. This non-overlap interval prevents noise by ensuring that when voltage is supplied to one data line, no voltage is supplied to other channels simultaneously. This preliminary prevention of overlapping activation eliminates the harmful noise effect while maintaining acceptable scanning speed through proper interval configuration.
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
This approach enables accurate and efficient charging of pixel capacitors to target voltages, reducing errors and maximizing driving time while minimizing circuit size through time division of DAC outputs.
Implementation Method 1
leveraging charge sharing between parasitic and pixel capacitors
Data Source
AI summary
A source driver and a display device having the same are provided. The source driver shares several outputs by using a time division method and has an analog voltage stored in a buffer supplied to each data line multiple times during a horizontal scanning interval. Accordingly, by supplying an analog voltage to a data line a first time in a first activation interval and supplying an analog voltage to a data line a second time in a second activation interval, a target voltage of each pixel may be achieved quickly and accurately.