Electrophotographic Photosensitive Member Axial Potential Bias
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Bias in dark electric potential along the electrophotographic photosensitive member leads to variations in electrostatic adhesion of toner, resulting in defective images formed on recording media.
Innovation Solution
The electrophotographic photosensitive member is designed with a cylindrical body and a photosensitive layer where the dark electric potential gradually increases from the first end portion to the second end portion, with a controlled charging ability, ensuring a consistent slope of the primary approximate line between 0.4V/cm and 1.5V/cm, and a difference not exceeding 10V, to maintain uniform toner adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the electrophotographic photosensitive member is rotated by a power transmitter with firm fixation at one end and play at the other end, then the rotation is enabled, but the distance between the photosensitive member and electrification mechanism varies along the axial direction, causing bias in dark electric potential
Solution Approach 1:
The patent applies local quality by creating a non-uniform photosensitive layer thickness along the axial direction. The layer thickness is deliberately made smaller at the first end portion (near power transmitter) and larger at the second end portion (near bearing). This compensates for the distance variation caused by rotation mechanism play, ensuring uniform dark electric potential distribution across the axial direction despite the mechanical imperfections.
Solution Approach 2:
The patent changes the physical parameter of photosensitive layer thickness to compensate for mechanical variations. By adjusting the thickness parameter locally (smaller at one end, larger at the other), the patent offsets the effect of varying distances between the photosensitive member and electrification mechanism, thereby maintaining consistent dark electric potential and uniform toner adhesion across the entire axial length.
2Manufacturing precision
If the dark electric potential is uniform across the axial direction, then the toner adhesion should be consistent, but the variation in distance to electrification mechanism causes bias in dark electric potential and non-uniform toner adhesion
Solution Approach 1:
The patent implements local quality by making the photosensitive layer thickness position-dependent. The thickness is deliberately reduced at the first end portion and increased at the second end portion along the axial direction. This local variation in thickness compensates for the distance variation to the electrification mechanism, ensuring that the dark electric potential remains consistent across all axial positions, thereby achieving uniform toner adhesion.
Solution Approach 2:
The patent applies preliminary anti-action by pre-compensating for the expected dark electric potential bias through non-uniform layer thickness design. Before the actual charging process occurs, the structure is designed to counteract the anticipated effect of distance variation, thereby preventing bias in dark electric potential and ensuring reliable, uniform toner adhesion across the entire photosensitive member surface.
3Reliability
If the photosensitive layer thickness is made non-uniform to compensate for distance variation, then dark electric potential uniformity is improved, but the layer thickness control precision becomes more challenging
Solution Approach 1:
The patent applies local quality by specifying precise thickness variations at different axial positions. The photosensitive layer is designed with controlled thickness gradients - thinner at the first end portion and thicker at the second end portion. This deliberate non-uniformity compensates for mechanical play in the rotation system, ensuring uniform dark electric potential despite the increased complexity of thickness control during manufacturing.
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 design prevents bias in electrostatic adhesion of toner, thereby ensuring consistent image density across the recording medium, reducing variations and improving image quality.
Implementation Method 1
charging the photosensitive layer with a constant charging ability in the axial direction
Implementation Method 2
the electrophotographic photosensitive member is electrically charged at its surface and then rotated while being irradiated by laser light for exposure, according to an image pattern, so that an electrostatic latent image is formed
Implementation Method 3
the latent image is developed by attaching toner to the photosensitive member
Data Source
AI summary
The present invention relates to an electrophotographic photosensitive member including a substantially cylindrical body rotated by rotation power transmitted via an first end portion from in an image forming apparatus and a photosensitive layer including a latent image forming area formed on an outer circumference of the body. The present invention also relates to an image forming apparatus provided with the electrophotographic photosensitive member. In the photosensitive layer, when the body is charged with a constant charging ability in the axial direction, dark electric potential at the latent image forming area gradually becomes larger as proceeding in the axial direction of the body, from the first end portion to a second end portion opposite to the first end portion.