Electrostatic Latent Image Measurement Using Electron Beam Scanning
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Solution Overview
Problem
Current methods fail to accurately measure electrostatic latent images on photoconductors due to difficulties in maintaining surface charge distribution and achieving high-resolution imaging without damaging the sample, especially for cylindrical photoconductors with conductive properties.
Innovation Solution
An electrostatic latent image measuring device using a charged particle optical system with an electron beam to charge and scan the photoconductor, combined with a semiconductor laser exposure system that controls light emission to form and measure electrostatic latent images with high resolution, while minimizing offset emissions and maintaining the integrity of the surface charge distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a head sensor is moved closer to the sample to achieve high spatial resolution (10 μm or below), then measurement precision is improved, but the measurement time increases and natural discharge or absorption occurs during measurement
Solution Approach 1:
The patent replaces the mechanical scanning system with a charged particle beam system. Instead of moving a physical sensor close to the sample surface, an electron beam is used to scan and detect the electrostatic latent image from a distance, eliminating the need for precise mechanical positioning and reducing measurement time while maintaining high spatial resolution
Solution Approach 2:
The patent introduces a charged particle beam as an intermediary between the sensor and the sample. The electron beam acts as a mediator that can detect surface potential distribution without requiring direct contact or close proximity to the sample, thus avoiding the time-consuming mechanical movement while achieving high measurement precision
2Measurement precision
If the head sensor is moved closer to the sample for accurate distance measurement, then measurement precision is improved, but the electrostatic latent image varies due to natural discharge or absorption during repeated measurements
Solution Approach 1:
The patent replaces the mechanical sensor positioning system with a charged particle beam scanning system. The electron beam can accurately measure surface potential distribution without requiring the sensor to be physically close to the sample, thereby preventing natural discharge or absorption that occurs during repeated close-proximity measurements
Solution Approach 2:
The patent performs the measurement using a charged particle beam that can rapidly scan the sample surface before significant natural discharge or absorption occurs. This preliminary action captures the electrostatic latent image in its original state, ensuring reliability of the measurement
3Device complexity
If conventional measurement methods are used, then device complexity is reduced, but the electrostatic latent image cannot be directly measured with high accuracy
Solution Approach 1:
The patent employs a charged particle beam system that combines optical and electronic components to directly measure electrostatic latent images. This approach achieves high measurement accuracy by using electron beam scanning and detection, overcoming the limitations of conventional mechanical measurement methods while maintaining reasonable device complexity
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 precise measurement of electrostatic latent images on photoconductors with high accuracy and resolution, allowing for the evaluation of image quality and process improvements without damaging the sample, and effectively addresses the challenges of dark decay and charge maintenance.
Implementation Method 1
a charged particle optical system A10 for irradiating an electron beam and charging a photoconductor sample
Implementation Method 2
an exposure optical system A20 for forming an electrostatic latent image on a surface of the photoconductor sample
Implementation Method 3
a scanning unit which scans a surface of the photoconductor sample by the electron beam, a distribution of the electrostatic latent image on the surface of the sample being measured by a signal detected by the scanning
Data Source
AI summary
An electrostatic latent image measuring device includes a charged particle optical system which irradiates an electron beam and charges a photoconductor sample, an exposure optical system which forms an electrostatic latent image on a surface of the photoconductor sample, and a scanning unit which scans the surface of the photoconductor sample by the electron beam, a distribution of the electrostatic latent image on the surface of the sample being measured by a signal detected by the scanning.