Counter Development Toner Control for Fog Reduction
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Solution Overview
Problem
Conventional image forming methods using organic photoreceptors face issues with forming high-density, uniform, and high-resolution images, particularly in the counter development mode, where fog, edge section density insufficiencies, and worm-like unevenness occur due to triboelectric charging and relative velocity between the photoreceptor and developing sleeve.
Innovation Solution
The method involves using toners with specific particle size distributions and water content, where 8% of toner particles have a diameter of 0.7 times the median diameter or less, and a water content of 0.1-2.0 mass%, along with an intermediate layer containing inorganic particles in the organic photoreceptor, to enhance image quality and reduce fog and unevenness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If counter developing mode is used to form high density dot image, then developing property is improved and high density dot image can be formed, but fog is generated and insufficient density is easily generated in the leading edge part
Solution Approach 1:
The patent applies parameter changes by precisely controlling the particle size distribution of toner particles, specifying that 8% of toner particles have a diameter of 0.7 times the median diameter or less, and controlling water content at 0.1-2.0 mass%, to optimize developing properties and reduce fog in counter developing mode
Solution Approach 2:
The patent uses composite materials by incorporating an intermediate layer containing inorganic particles between the conductive supporting body and the photosensitive layer, creating a multi-layer structure that improves image quality and reduces fog generation during counter developing
2Productivity
If relative velocity between organic photoreceptor and developing sleeve is increased, then developing speed is improved, but triboelectric charging becomes stronger and worm-like unevenness occurs
Solution Approach 1:
The patent applies parameter changes by optimizing the particle size distribution of toner particles, with specific control over fine particle content (8% at 0.7×Dp50 or less), to reduce triboelectric charging effects and prevent worm-like unevenness even at higher developing speeds
Solution Approach 2:
The patent applies local quality by introducing an intermediate layer with specific inorganic particles at the interface between the conductive supporting body and photosensitive layer, creating a localized region that reduces triboelectric charging and prevents worm-like unevenness
3Measurement precision
If high density dot exposure is conducted with small diameter spot, then high accurate latent image is formed, but transverse line image becomes thin and trailing edge becomes white omission
Solution Approach 1:
The patent applies parameter changes by controlling the particle size distribution of toner particles, specifically setting 8% of particles at 0.7 times the median diameter or less, to improve toner deposition characteristics and prevent transverse line thinning and trailing edge white omission
Solution Approach 2:
The patent uses an intermediate layer containing inorganic particles as a mediator between the photosensitive layer and developing sleeve, improving charge transfer efficiency and enabling uniform high-density image formation without transverse line defects or trailing edge white omission
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 enables the formation of high-quality digital images with improved edge section density and reduced fog and worm-like unevenness, achieving both high resolution and sharpness in the counter development mode.
Implementation Method 1
when a relative velocity between a organic photoreceptor and a developing sleeve becomes faster and a triboelectric charging between a magnetic brush of a developer and a organic photoreceptor becomes stronger
Data Source
AI summary
A toner image is formed while a developing sleeve is rotated in a direction counter to that of an organic photoreceptor at the developing section and a developing agent contains toner which contains toner particles having a particle diameter of 0.7×(Dp50) or less in an amount of 8 number % or less and has water content of 0.1 to 2.0 mass % under an environment of 30° C. and 80% RH, where Dp50 represents 50% number % particle diameter of toner particles.