Image Forming Apparatus Lubricant Control for Density Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electrophotographic image forming apparatuses face issues with uneven image density due to fluctuations in the developing gap and uneven application of lubricant, particularly when using AC bias development, which can lead to streaky image density unevenness and reduced operational life of photoconductors.
Innovation Solution
An electrophotographic image forming apparatus with a latent image bearer, a lubricant applicator applying at least 0.845 mg of lubricant per kilometer, and a developing device using a developing voltage with a peak-to-peak difference of 200 V to 400 V, incorporating two developing rollers to improve toner adherence and developability, and using AC bias for color toners while maintaining DC bias for black toner to minimize streaky image density unevenness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If AC bias development is used to ameliorate uneven image density caused by developing gap fluctuations, then image density uniformity is improved, but streaky image density unevenness occurs due to uneven lubricant application
Solution Approach 1:
The patent applies principle 35 by optimizing the lubricant application amount to a specific range (0.845 mg/cm or more per 1.0 km running distance) and controlling the AC component peak-to-peak voltage within 200 V to 400 V. This parameter optimization resolves the contradiction by finding the optimal balance point where sufficient lubrication prevents streaking while the AC bias maintains image density uniformity.
2Duration of action of stationary object
If lubricant is applied to extend operational life of photoconductors, then durability is improved, but uneven application causes streaky image density unevenness
Solution Approach 1:
The patent applies principle 35 by precisely controlling the lubricant application amount within a specific range (0.845 mg/cm or more per 1.0 km running distance). This optimized parameter ensures sufficient lubrication for extended photoconductor life while preventing excessive application that would cause streaking, thus resolving the contradiction between durability and image quality.
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 solution effectively alleviates uneven image density caused by developing gap fluctuations and suppresses streaky image density unevenness, enhancing the operational life of photoconductors and achieving high image quality and developability comparable to typical AC bias development.
Implementation Method 1
a lubricant applicator to apply lubricant onto a surface of the latent image bearer
Implementation Method 2
a charging device to charge the a latent image bearer
Implementation Method 3
a developing device to develop the latent image with developer including toner and use a developing voltage including an AC component
Data Source
AI summary
An electrophotographic image forming apparatus includes a latent image bearer to rotate and bear a latent image, a charging device to charge the a latent image bearer, a developing device to develop the latent image with developer including toner and use a developing voltage including an AC component, and a lubricant applicator to apply lubricant onto a surface of the latent image bearer. An amount of the lubricant applied by the lubricant applicator onto the latent image bearer per centimeter in an axial direction of the latent image bearer is equal to or greater than 0.845 mg for a running distance of 1.0 kilometer of the latent image bearer, and a difference between a largest value and a smallest value of the developing voltage is in a range of 200 V to 400 V.