Electrostatic Printer Humidity Control for Corona Breakdown
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Solution Overview
Problem
In electrostatic printing, achieving high-quality image transfer from a photoconductor to an intermediate transfer member is hindered by corona breakdown, which damages the transfer member and affects print quality, and is often necessitated by high bias voltages that are above the corona breakdown threshold, leading to reduced apparatus lifespan and inconsistent color consistency.
Innovation Solution
Incorporating a humidity raising device that increases the relative humidity above ambient levels in the transfer region, allowing for lower bias voltages and reduced mechanical load, thereby preventing corona breakdown and maintaining print quality without compromising the transfer member's integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high bias voltages are used to achieve high-quality image transfer, then image transfer quality is improved, but corona breakdown occurs damaging the transfer member
Solution Approach 1:
The invention changes the environmental parameter of relative humidity in the transfer region from ambient levels to elevated levels (e.g., 40-70% RH). This parameter change modifies the electrical breakdown characteristics of air, allowing high-quality image transfer at lower bias voltages that remain below the corona breakdown threshold, thus resolving the contradiction between transfer quality and damage prevention
Solution Approach 2:
The invention introduces humidity-controlled air as an intermediary medium between the photoconductor and transfer member. This controlled atmosphere acts as a mediator that enables efficient charge transfer while preventing direct corona discharge damage to the transfer member surface
2Manufacturing precision
If high bias voltages are applied to ensure complete toner transfer, then transfer completeness is improved, but transfer member lifespan is reduced
Solution Approach 1:
By elevating the relative humidity parameter in the transfer region, the invention enables complete toner transfer at reduced bias voltages that do not cause corona breakdown, thereby extending the operational lifespan of the transfer member while maintaining transfer completeness
3Device complexity
If ambient humidity conditions are maintained, then device complexity is low, but color consistency becomes inconsistent
Solution Approach 1:
The invention deliberately changes the humidity parameter from uncontrolled ambient conditions to controlled elevated conditions, creating a stable electrical environment that ensures consistent color reproduction across different operating conditions
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 increased humidity enables the use of lower bias voltages and mechanical loads, reducing corona breakdown, extending the lifespan of the transfer member, improving color consistency, and maintaining print quality, while also reducing residual electrical charges on the photoconductor and charge roller.
Implementation Method 1
transfer a layer of electrostatic printing material from the photoconductor to the transfer member at a transfer region under the action of an applied potential difference
Implementation Method 2
a humidity raising device which is operable to raise the relative humidity of the transfer region above an ambient level
Data Source
AI summary
There is disclosed an apparatus which may comprise a transfer member and a photoconductor. The apparatus may be operable to apply a potential difference between the transfer member and the photoconductor and the photoconductor may be operable to transfer a layer of electrostatic printing material from the photoconductor to the transfer member at a transfer region under the action of the applied potential difference. According to the present disclosure, the apparatus may further comprise a humidity raising device which may be operable to raise the relative humidity of the transfer region above an ambient level. A printer and a method of facilitating transfer of electrostatic printing material are also disclosed.