Protrusion on Drive Substrate for Offset Printing Alignment
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Solution Overview
Problem
In the manufacturing of organic electroluminescence (EL) display devices, the use of flat blankets for offset printing leads to difficulties in accurately transferring print patterns, resulting in misalignment and color unevenness due to bending and irregularities, which degrades image quality.
Innovation Solution
The implementation of a protrusion on the drive substrate that protrudes beyond any layer formed on it, serving as a starting point for contact with the blanket during offset printing, ensures accurate transfer of print patterns and suppresses distortion in the light emission region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a flat blanket is used for offset printing to form the print pattern layer, then the printing process can be completed, but the blanket bends and becomes irregular during contact with the printed substrate, causing misalignment and color unevenness
Solution Approach 1:
The protrusion is formed on the drive substrate before the offset printing process to establish a predetermined contact starting point. This preliminary structural feature guides the blanket contact sequence, ensuring that printing begins at a fixed location and progresses in a controlled manner, thereby preventing misalignment and color unevenness caused by blanket bending during the printing process
2Productivity
If the blanket contacts the printed substrate without a predetermined starting point, then the printing can proceed, but distortion occurs in the light emission region due to blanket irregularities
Solution Approach 1:
The contact between the blanket and drive substrate is segmented into a controlled sequence starting from a specific location defined by the protrusion. Instead of simultaneous contact across the entire surface, the printing process is divided into stages beginning at the protrusion location, which eliminates distortion in the light emission region while maintaining printing efficiency
Data Source
AI summary
An organic electroluminescence display device includes: a light emission region including a plurality of pixels on a drive substrate, wherein each of the pixels includes, in order from a side close to the drive substrate, a first electrode, a functional layer, and a second electrode, the first electrode is provided for each of the pixels, and the functional layer includes at least an organic electroluminescence layer; a print pattern layer included in the functional layer and formed individually for each of the pixels; and a protrusion provided on the drive substrate and protruding further than any layer provided between the print pattern layer and the drive substrate.