Electrostatic Imaging Member Pre-Exposure Charging
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Solution Overview
Problem
Conventional xerographic printing processes are limited by the need for a photodischarge period, which restricts system compactness and speed, and existing solutions have not fully resolved these issues.
Innovation Solution
An electrostatic imaging device with a light-sensitive charge transport layer and a charge generation layer, where charge acceptance is controlled by pre-exposure to light, allowing latent image formation during the charging step without a photodischarge period, using a substrate, charge generation layer, and charge transport layer with a charge transport molecule.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional photodischarge process is used to create latent image, then latent image can be formed, but system speed is limited by photodischarge period and system compactness is restricted
Solution Approach 1:
The patent extracts and eliminates the photodischarge step from the conventional xerographic process. By using a charge retentive surface that accepts charge during the charging step itself (rather than requiring separate charging followed by photodischarge), the latent image is formed directly during charging, removing the time-consuming photodischarge period and enabling higher system speeds
Solution Approach 2:
The patent applies preliminary light exposure to specific areas of the photoconductor before the charging step. This pre-exposure modifies the electrical properties of those areas so they do not accept charge during subsequent charging, thereby creating the latent image pattern in advance of the actual charging process and eliminating the need for post-charging photodischarge
2Productivity
If photodischarge period is used, then latent image formation is achieved, but device geometry is constrained and system compactness is limited
Solution Approach 1:
The patent merges the latent image formation process with the charging process into a single simultaneous operation. By using a charge retentive surface that responds to pre-exposure light patterns, the charging step itself creates the latent image without requiring a separate photodischarge step, thereby reducing device complexity and enabling more compact system geometry
Solution Approach 2:
The patent removes the photodischarge step from the process sequence, eliminating the associated time delay and spatial requirements. This extraction of the unnecessary step allows for more compact device design and simplified process architecture while maintaining latent image formation capability
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
Enables high-speed, compact xerography by eliminating the need for a photodischarge period and allowing simultaneous charging and latent image formation, enhancing system speed and compactness.
Implementation Method 1
a charge transport layer comprising a charge transport molecule disposed on the charge generation layer, wherein the electrostatic imaging member is light-sensitive
Data Source
AI summary
Embodiments pertain to a method of creating an electrostatic latent image through use of an electrostatic latent image generating device comprising a single exposing device for selectively exposing a surface of the electrostatic imaging member to light, and a single electrostatic charging device for charging the surface of the electrostatic imaging member, wherein the exposing device is located before the electrostatic charging device such that the exposing the surface of the electrostatic imaging member to light precedes the charging the surface of the electrostatic imaging member and wherein charge is not accepted by the exposed surface of the electrostatic imaging member and the charge is accepted by the unexposed surface of the electrostatic imaging member.