Photosensitive Member Composition for Ghost Image Suppression
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Solution Overview
Problem
Image defects such as ghost images occur in electrophotographic image forming apparatuses without static eliminators due to residual charge polarity, leading to afterimages from previous rotations, which are not effectively addressed by existing technologies.
Innovation Solution
An electrophotographic photosensitive member with a charge generating layer containing phthalocyanine pigment and a specific absorbance ratio, and a charge transport layer with controlled dispersion of phthalocyanine pigment, along with a conductive substrate, to inhibit ghost images by optimizing charge distribution and reducing foreign substances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a static eliminator is removed to save space and reduce cost, then device complexity and cost are reduced, but ghost images occur due to residual charge polarity
Solution Approach 1:
The charge generating layer is designed to automatically eliminate residual charge polarity through its inherent properties (phthalocyanine pigment with specific absorbance ratio and controlled dispersion), making the system self-serving without requiring an external static eliminator device
Solution Approach 2:
The patent changes the chemical and optical parameters of the charge generating layer by specifying the phthalocyanine pigment type, its absorbance ratio A830/A783 between 0.97-1.10, and dispersion control, which fundamentally alters how the layer handles residual charge and prevents ghost images
2Reliability
If the phthalocyanine pigment dispersion is optimized to reduce foreign substances, then image quality is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent specifies precise optical parameters (absorbance ratio A830/A783 between 0.97-1.10) and dispersion control parameters for the phthalocyanine pigment, which standardizes the manufacturing process and makes high precision achievable through measurable targets
Solution Approach 2:
The patent replaces mechanical mixing methods with optical characterization (absorbance measurement at specific wavelengths) to control and verify pigment dispersion, substituting physical manipulation with optical feedback for more precise control
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 reduces ghost images by ensuring balanced dispersion and minimizing foreign substances, enhancing image quality and reliability in image forming apparatuses without static eliminators.
Implementation Method 1
A ratio A830/A783 of a second absorbance A830 to a first absorbance A783 of the charge generating layer is at least 0.97 and no greater than 1.10. The first absorbance A783 is an absorbance of the charge generating layer with respect to first light with a wavelength of 783 nm. The second absorbance A830 is an absorbance of the charge generating layer with respect to second light with a wavelength of 830 nm.
Data Source
AI summary
An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer includes a charge generating layer and a charge transport layer. The charge generating layer contains a phthalocyanine pigment and a first resin. A ratio of the mass of the phthalocyanine pigment to the mass of the first resin is greater than 2.0 and less than 3.5. A ratio A830/A783 of a second absorbance A830 to a first absorbance A783 of the charge generating layer is at least 0.97 and no greater than 1.10. The first absorbance A783 is an absorbance of the charge generating layer with respect to first light with a wavelength of 783 nm. The second absorbance A830 is an absorbance of the charge generating layer with respect to second light with a wavelength of 830 nm.