Rubbing System for LCD Alignment Layer Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing rubbing systems for liquid crystal display (LCD) devices face challenges in maintaining uniform pressure on larger substrates, leading to defects in the alignment layer due to increased width and weight of the rubbing roll, which affects the uniformity of microstructures formed on the alignment layer.
Innovation Solution
A rubbing system that simultaneously lifts and lowers both the rubbing table and the rubbing roll to maintain a uniform gap between the alignment layer and the rubbing roll, allowing for precise control of the alignment controlling force and rubbing intensity, thereby ensuring uniform microstructure formation across the alignment layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the rubbing roll width and weight are increased to process larger LCD substrates, then the processing capability for large substrates is improved, but the uniformity of pressure applied to the substrate deteriorates
Solution Approach 1:
The rubbing system is divided into multiple independent rubbing rolls (first rubbing roll, second rubbing roll, third rubbing roll) that can be independently controlled. Each rubbing roll can be adjusted separately in terms of position, pressure, and rotation speed, allowing uniform pressure distribution across large substrates while maintaining the capability to process various substrate sizes.
Solution Approach 2:
The rubbing rolls are designed with dynamic adjustment capabilities, including independent rotation speed control and position adjustment mechanisms. The rotation speeds of different rubbing rolls can be varied (e.g., first rubbing roll at 1-10 rpm, second at 10-50 rpm, third at 50-100 rpm), and their positions can be adjusted to maintain optimal contact pressure across the entire substrate surface during the rubbing process.
2Area of stationary object
If a single heavy rubbing roll is used to cover large substrate areas, then the coverage area is improved, but the control over gap and pressure uniformity deteriorates
Solution Approach 1:
Instead of using a single large rubbing roll, the system employs multiple smaller rubbing rolls arranged to cover the entire substrate area. Each rubbing roll can be independently positioned and adjusted, ensuring uniform gap control across the large substrate while maintaining precise control over the alignment layer treatment in each region.
Solution Approach 2:
Each rubbing roll can be independently adjusted to provide locally optimized rubbing conditions. The rotation speed, position, and pressure of each rubbing roll can be tailored to the specific requirements of different regions of the substrate, ensuring uniform gap and pressure distribution across the entire large substrate area.
3Force
If the rubbing roll weight is increased to maintain contact pressure on large substrates, then the contact pressure is improved, but the ease of maintaining uniform pressure deteriorates
Solution Approach 1:
The total contact pressure requirement is distributed across multiple lighter rubbing rolls instead of concentrating it in one heavy roll. Each rubbing roll applies a portion of the total pressure, and their individual pressures can be independently adjusted and controlled, making it easier to maintain uniform pressure distribution across the substrate.
Solution Approach 2:
The system controls contact pressure by adjusting operational parameters (rotation speed, position, and weight distribution) of multiple rubbing rolls rather than relying on a single heavy roll. By varying the rotation speeds of different rubbing rolls and their positional parameters, uniform contact pressure is achieved more easily through parameter optimization rather than increasing individual roll weight.
Data Source
AI summary
A rubbing system for an alignment layer of a liquid crystal display (LCD) device, comprises: a rubbing table on which a substrate having an alignment layer thereon is positioned; a rubbing roll on which a rubbing material is wound, substantially positioned on the rubbing table thus to substantially contact the alignment layer, for rubbing the alignment layer by rotation of the rubbing roll; and a controlling unit for controlling the alignment layer to be rubbed by substantially contacting the rubbing roll onto the alignment layer by simultaneously lifting and lowering a rubbing table and the rubbing roll according to an alignment controlling force to be applied to the alignment layer.