Organic Photosensitive Drum Coating Alignment and Bubble Control
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Solution Overview
Problem
The existing methods for manufacturing organic photosensitive drums for electrophotography face challenges such as gripping failure due to coaxial misalignment, solvent vapor bubble discharge, and increased manufacturing costs due to unnecessary application of high-priced photosensitive solution on the inner surface, leading to non-uniform coating and potential image distortion.
Innovation Solution
A method involving a gripping mechanism that aligns and grips the hollow cylinder with precise lower end alignment, minimizing the space between the gripping mechanism and the photosensitive solution, and using a solvent with a relative evaporation speed of 1.9 to 5 to prevent bubble discharge and apply the photosensitive solution only to the outer surface, thereby reducing material waste and ensuring uniform coating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional immersion coating method is used without precise alignment, then the coating process is simple, but gripping failure occurs due to coaxial misalignment
Solution Approach 1:
The patent applies preliminary action by performing alignment adjustment before the gripping operation. The alignment adjustment mechanism pre-positiones the hollow cylinder relative to the gripping mechanism, ensuring coaxial alignment is established in advance. This prevents gripping failure while maintaining a relatively simple overall device structure, as the alignment is performed once before coating rather than requiring continuous complex adjustment during the process.
2Manufacturing precision
If high volatile solvent is used to reduce coating amount deviation, then coating uniformity improves, but solvent vapor bubble discharge occurs
Solution Approach 1:
The patent converts the harmful effect of solvent vapor bubble discharge into a beneficial process control parameter. By introducing a heating unit that specifically heats the lower portion of the hollow cylinder, the patent controls the vaporization rate of the high volatile solvent. This controlled vaporization prevents bubble discharge while maintaining the coating uniformity benefits of using high volatile solvents. The harmful bubbles are transformed into a controlled phase change process that improves coating quality.
Solution Approach 2:
The patent applies parameter changes by controlling the temperature of the lower portion of the hollow cylinder through the heating unit. This temperature parameter control regulates the evaporation rate of the solvent, preventing bubble discharge while maintaining coating uniformity. The local heating creates a temperature gradient that controls vaporization without affecting the overall coating process.
3Manufacturing precision
If photosensitive solution is applied to inner surface, then coating completeness improves, but manufacturing cost increases due to material waste
Solution Approach 1:
The patent extracts the unnecessary coating application from the inner surface of the hollow cylinder. By modifying the immersion coating process to prevent solution penetration into the inner surface, the patent eliminates material waste while maintaining coating completeness on the outer surface. The coating process is selectively applied only where needed, extracting the harmful effect of unnecessary material consumption.
4Reliability
If gripping mechanism enters deeply into hollow cylinder, then gripping reliability improves, but coaxial misalignment increases
Solution Approach 1:
The patent performs alignment adjustment before the gripping mechanism enters the hollow cylinder. The alignment adjustment mechanism pre-establishes the correct relative position and coaxial alignment between the gripping mechanism and the hollow cylinder. This preliminary alignment ensures that when the gripping mechanism enters deeply for reliable gripping, the coaxial alignment is already maintained, preventing misalignment issues.
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 approach minimizes gripping failures, reduces manufacturing costs, and achieves uniform image density by preventing solvent vapor bubble discharge and ensuring the inner surface remains uncoated, thus enhancing image quality and reducing runout tolerance.
Implementation Method 1
a gripping mechanism that aligns and grips the hollow cylinder with precise lower end alignment, minimizing the space between the gripping mechanism and the photosensitive solution
Implementation Method 2
using a solvent with a relative evaporation speed of 1.9 to 5 to prevent bubble discharge and apply the photosensitive solution only to the outer surface
Data Source
AI summary
Disclosed is a method for manufacturing an organic photosensitive drum for electrophotography, which includes a step of immersing a hollow cylinder into a liquefied photosensitive material after gripping the hollow cylinder, by using a coating device including: a transfer tray in which the hollow cylinder is inserted and loaded into at least one jig vertically provided on a plate type pallet; and a gripping assembly disposed above the transfer tray and including at least one gripping mechanism. The process of gripping the hollow cylinder includes: inserting a portion or the whole of the gripping mechanism into the hollow cylinder; aligning a lower end of the gripping mechanism with a lower end of the hollow cylinder; and gripping the hollow cylinder by using the gripping mechanism.