Dual Wiper Blade Cleaning System for Photoconductive Surface
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Solution Overview
Problem
In liquid electrophotography (LEP) printing, 'CR rings' occur due to oxidized imaging oil stripes on the photoconductive surface, leading to print-quality issues and requiring frequent replacement of the charge roller and photo imaging plate, as single wiper blade systems fail to maintain charging uniformity.
Innovation Solution
A dual wiper blade cleaning system where a second wiper blade, positioned downstream, removes excess imaging oil wakes from the first wiper blade, maintaining uniform imaging oil distribution and preventing oxidization, thereby extending the lifespan of the photoconductive surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single wiper blade is used to clean the photoconductive surface, then the cleaning function is simple and device complexity is low, but imaging oil wakes are created causing oxidization and charging uniformity degradation
Solution Approach 1:
The cleaning system is divided into two separate wiper blades positioned at different locations. The first wiper blade cleans the photoconductive surface at a first position, while the second wiper blade cleans at a second position downstream in the rotation direction. This segmentation prevents imaging oil wakes from forming and reaching the charging region, maintaining charging uniformity without excessive complexity.
2Reliability
If a second wiper blade is added downstream to remove imaging oil wakes, then charging uniformity is maintained and reliability improves, but device complexity increases
Solution Approach 1:
The second wiper blade is positioned downstream of the first wiper blade in the rotation direction of the photoconductive surface. By placing the second cleaning action after the first, the system preliminarily removes imaging oil wakes before they can travel around and cause oxidization, preventing the harmful effect before it occurs.
3Volume of moving object
If wiper blades are positioned close together, then the cleaning system is compact, but imaging oil wakes from the first blade may reach the second blade reducing effectiveness
Solution Approach 1:
The two wiper blades are positioned at different locations along the rotation path of the photoconductive surface, with the second blade downstream of the first. This spatial arrangement ensures that each blade performs its cleaning function at a specific location, preventing imaging oil wakes from interfering with the second blade's effectiveness while maintaining a compact overall system.
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 dual wiper blade system effectively prevents the formation of oxidized imaging oil stripes, ensuring consistent charging and reducing the need for premature replacement of the photoconductive surface and charge roller, thus enhancing print quality and operational efficiency.
Implementation Method 1
a wiper blade that wipes ink residues from the photoconductive surface
Implementation Method 2
a blade having a configuration which deflects material away from the surface undergoing cleaning while it cleans the surface as a scraper blade
Implementation Method 3
a charge roller (CR) may be used to charge the photoconductive surface
Implementation Method 4
a laser, to provide for a latent image on the photoconductive surface
Implementation Method 5
ink (liquid toner) or other printing fluid which includes small color particles suspended in a fluid (imaging oil) that can be attracted or repelled to a photoconductive surface
Data Source
Figure 1~2
Figure 3
AI summary
Cleaning a photoconductive surface (16) from particles and excess fluid with at least two wiper blades, wherein a first wiper blade (12) is to contact the photoconductive surface (16) and to wipe at least some of the particles and at least some of the excess fluid from the photoconductive surface (16) and wherein a second wiper blade (14) is to contact the photoconductive surface (16) and to wipe at least some of the particles and at least some of the excess fluid that have passed the first wiper blade, from the photoconductive surface (16).