Time-Division TFT Control Circuit Eliminates Shutdown Afterimages
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Solution Overview
Problem
The existing technologies for TFT-LCDs face issues with shutdown afterimages and circuit burnout due to excessive current during shutdown, particularly in high-resolution and large-size displays, where gold particles in the ACF glue fuse under high instantaneous current, leading to abnormal display and circuit damage.
Innovation Solution
A circuit utilizing time division circuits with comparators, MOS transistors, resistors, and capacitors is designed to generate voltages for turning on TFTs in a time-division manner, ensuring that TFTs are turned on sequentially rather than simultaneously, thereby reducing the instantaneous current and preventing circuit burnout.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a function of turning on all TFTs simultaneously at shutdown is used to eliminate shutdown afterimages, then shutdown afterimages are eliminated, but instantaneous current becomes excessively large causing gold particles to fuse and circuit burnout
Solution Approach 1:
The patent divides the simultaneous turning-on action into multiple sequential stages. The turning-on voltage is applied in a time-division manner across different row segments, with each row group turning on at different time points. This segmentation transforms a single high-current event into multiple lower-current events, resolving the contradiction between eliminating afterimages and preventing circuit burnout.
2Reliability
If the number of gold particles is increased and homogeneity is improved to prevent fusion, then circuit reliability is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent implements preliminary action by controlling the sequence and timing of voltage application to different row groups before the actual turning-on occurs. The time-division control circuit pre-establishes a turning-on schedule that staggers the current demand, preventing gold particle fusion without requiring changes to the physical bonding structure or increased gold particle quantity.
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 solution effectively eliminates shutdown afterimages by ensuring that significant discontinuous differences in the display are not perceived, while preventing circuitry burnout from excessive current, and allows for area-division control to reduce instantaneous current during shutdown.
Implementation Method 1
a comparator, a MOS transistor, a first resistor, a second resistor, a third resistor and a capacitor, wherein a first terminal of the first resister serves as a first input terminal of the time division circuit of the stage
Implementation Method 2
an output terminal of the comparator is connected with a gate of the MOS transistor, a drain of the MOS transistor is connected with the second terminal of the first resistor
Implementation Method 3
a first terminal of the capacitor is grounded; and the inverting terminals of the comparators of the time division circuits in each stage are connected with each other
Implementation Method 4
a first terminal of the first resister serves as a first input terminal of the time division circuit of the stage, and a second terminal thereof serves as an output terminal of the time division circuit of the stage
Data Source
AI summary
The invention relates to a field of display technique. There is disclosed a circuit for eliminating shutdown afterimages of a display. By designing a circuit capable of generating voltages for tuning on TFTs in a time-division way, it is realized that when the display screen shuts down, not only the significant discontinuous differences of pictures are ensured to be not perceived by human eyes so as to eliminate the shutdown afterimages, but also such a problem can be avoided that the circuitry in the panel is burned out by the overlarge instantaneous current caused by the simultaneous turning on of all the TFTs at the moment of shutdown.