Electro-Optical Device Shielding Parasitic Capacitance
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Solution Overview
Problem
In electro-optical devices like liquid-crystal devices, parasitic capacitance between thin-film transistors causes image interference issues such as ghost images and cross-talk, especially at the boundaries between groups of simultaneously driven data lines, limiting high-definition image display.
Innovation Solution
The implementation of an electromagnetic shield between adjacent thin-film transistors reduces parasitic capacitance effects by shielding potential changes, allowing for reduced pitch of thin-film transistors and data lines while maintaining high image quality, with the shield being a conductive line set at a fixed potential or connected to lines of constant potential.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a plurality of data lines are simultaneously driven to display high-definition images, then image resolution is improved, but parasitic capacitance between thin-film transistors causes ghost images and cross-talk
Solution Approach 1:
An electromagnetic shield line is introduced as an intermediary element between adjacent thin-film transistors. This shield line, connected to a reference potential, mediates the electromagnetic interaction between neighboring transistors, blocking parasitic capacitance coupling and preventing signal interference while allowing the simultaneous driving of multiple data lines to maintain high-definition display
2Measurement precision
If the pitch of thin-film transistors and data lines is reduced to increase pixel density, then image definition is improved, but parasitic capacitance between adjacent transistors increases causing more ghost images
Solution Approach 1:
The electromagnetic shield line serves as a protective intermediary that enables closer spacing of thin-film transistors and data lines. By blocking parasitic capacitance coupling between adjacent transistors, the shield allows reduced pitch configurations that increase pixel density and improve image definition without suffering from increased ghost images or cross-talk
3Speed
If multiple sampling switches operate simultaneously to drive multiple data lines, then data transmission speed is improved, but interference between lines occurs due to parasitic capacitance
Solution Approach 1:
The electromagnetic shield line acts as a mediator that protects simultaneous data transmission operations. By blocking parasitic capacitance coupling between adjacent sampling switches and data lines, the shield maintains signal integrity and prevents cross-talk interference, allowing multiple sampling switches to operate simultaneously at high speeds without compromising reliability
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 minimizes ghost images and cross-talk, enabling high-quality, high-definition image display by reducing parasitic capacitance effects, and allows for a reduction in the pitch of data lines and pixels, improving overall image clarity.
Implementation Method 1
an electromagnetic shield disposed at least in some of spaces between two adjacent thin-film transistors
Data Source
AI summary
Exemplary embodiments of the present invention provide an electro-optical device having a sampling circuit including a plurality of thin-film transistors corresponding to respective data lines, the thin-film transistors each including i) a drain connected to a drain line extending from the data line, ii) a source connected to a source line extending from an image-signal line in the extending direction of the data line, and iii) a gate interposed between the drain line and the source line; a data-line driving circuit supplying sampling-circuit driving signals to the gate; and an electromagnetic shield disposed in a space between two adjacent thin-film transistors. This reduces the occurrence of image problems due to parasitic capacitance between the thin-film transistors in the sampling circuit.