Electrophoretic Display Color Filter Alignment via Pixel Pattern
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Solution Overview
Problem
Current electrophoretic display devices face challenges in achieving multicolor display with high productivity and maintaining color consistency when viewed from different angles, due to difficulties in aligning color filter layers with pixel electrodes and increased distance between display layers leading to tint fading.
Innovation Solution
A method involving a substrate with a pixel electrode and an electrophoretic display layer, where a color filter layer is formed using a pixel alignment pattern, allowing for precise alignment and reduced distance between layers, enhancing multicolor display capabilities and productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If color filter layers are formed between the microcapsule-type electrophoretic display layer and the transparent electrode, then multicolor display capability is achieved, but alignment difficulty between color filter layers and pixel electrodes increases and productivity decreases
Solution Approach 1:
The patent applies preliminary action by forming alignment marks on the substrate before bonding the stacked film. These pre-formed alignment marks serve as reference patterns that enable automatic alignment of the color filter layers with the pixel electrodes during the bonding process, eliminating the need for complex post-bonding alignment operations and thereby improving productivity while maintaining multicolor display capability
2Ease of manufacture
If the distance between the patterned color filter layers and the electrophoretic display layer increases, then ease of assembly is improved, but tint becomes faint in oblique observation
Solution Approach 1:
The patent resolves this contradiction by transitioning from a loose assembly approach to a bonded integrated structure. By bonding the stacked film (containing color filter layers) directly to the substrate (containing electrophoretic display layer), the invention maintains a minimal distance between layers in the vertical dimension while ensuring proper alignment through the alignment marks. This bonded structure prevents the distance increase that would occur with loose assembly, thereby maintaining tint intensity in oblique observation while still facilitating ease of assembly through the standardized bonding process
3Manufacturing precision
If alignment marks are formed on the substrate, then alignment precision between color filter layers and pixel electrodes is improved, but device complexity increases
Solution Approach 1:
The patent uses alignment marks as an intermediary element that facilitates precise alignment without adding functional complexity to the display operation. These alignment marks serve solely as reference patterns for positioning the color filter layers relative to the pixel electrodes during manufacturing. Once alignment is achieved, the alignment marks fulfill their purpose and do not interfere with the normal display function, thus providing high alignment precision while maintaining simplicity of the operational device
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 method enables multicolor display with minimal tint change even when viewed obliquely, improving productivity and maintaining color consistency by aligning color filter layers with pixel electrodes and reducing the distance between the electrophoretic display layer and color filters.
Implementation Method 1
This electrophoretic display panel operates by the principle that an electric field is applied to a dispersion containing charged particles dispersed, thereby moving the charged particles and displaying an image
Data Source
AI summary
A electrophoretic display device manufacturing method includes bonding a substrate including a pixel electrode and a stacked film including a transparent electrode layer and an electrophoretic display layer, and forming a color filter layer having a pixel pattern corresponding to a pattern of the pixel electrode above a base material surface of the stacked film. The substrate has a region where the electrophoretic display layer is not arranged when the substrate and the stacked film are bonded, a pixel alignment pattern is drawn in the region, and in the forming the color filter layer, the color filter layer is formed while performing alignment using the pixel alignment pattern.