Photoconductor Overcurrent Detection via Rotation-Synchronized Counting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image forming apparatuses face challenges in accurately determining overcurrents generated in synchronism with the rotation cycle of a photoconductor, which can be due to local deterioration or foreign matter attachment, leading to potential misidentification of the cause of overcurrents.
Innovation Solution
An image forming apparatus with a controller that counts overcurrent detection signals synchronized with the photoconductor's rotation cycle and determines if the count exceeds a threshold, distinguishing between cyclic and short-period abnormal discharges to accurately identify the source of overcurrents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If overcurrent detection is performed multiple times in a short time period to filter noise, then measurement reliability is improved, but the ability to detect cyclic overcurrents synchronized with photoconductor rotation deteriorates
Solution Approach 1:
The patent divides overcurrent detection into two separate evaluation methods: one for short-period repeated detections (to filter noise) and another for cyclic detections synchronized with photoconductor rotation (to detect localized flaws). This segmentation allows each method to optimize for its specific detection goal without interfering with the other.
Solution Approach 2:
The patent introduces a determination unit that acts as an intermediary between the detection unit and the control system. This unit integrates both detection methods and determines whether to issue warnings based on combined analysis, preventing false positives while maintaining sensitivity to actual cyclic overcurrents caused by photoconductor flaws.
2Measurement precision
If overcurrent threshold is set low to detect all potential issues, then measurement precision is improved, but false positive rate increases due to noise
Solution Approach 1:
The patent implements feedback mechanisms where detection results from multiple cycles are fed back into the determination unit. The system learns from repeated patterns and adjusts its response accordingly, issuing warnings only when cyclic overcurrents are confirmed across multiple rotation cycles, thereby reducing false positives while maintaining high sensitivity.
Solution Approach 2:
The patent performs preliminary detection and evaluation before issuing final warnings. The determination unit analyzes detection patterns in advance, comparing them against both noise criteria and cyclic pattern criteria, ensuring that warnings are issued only after thorough verification, thus balancing sensitivity with accuracy.
3Device complexity
If simple overcurrent detection is used to maintain device simplicity, then device complexity is reduced, but the ability to distinguish cyclic overcurrent causes deteriorates
Solution Approach 1:
The patent designs the determination unit to perform multiple functions: it evaluates both short-period repeated detections and cyclic detections synchronized with photoconductor rotation. This multi-functional approach allows a single component to provide comprehensive overcurrent analysis without requiring separate dedicated systems for each detection type.
Solution Approach 2:
The patent merges the detection unit and determination unit into an integrated system where detection signals are immediately evaluated against multiple criteria. This combination eliminates the need for separate analysis stages and reduces overall system complexity while maintaining the ability to distinguish between noise-induced overcurrents and those caused by photoconductor flaws.
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 precise determination of cyclic abnormal discharges caused by photoconductor flaws or foreign matter, allowing for timely user notifications and preventive measures such as cleaning or replacement, thereby preventing photoconductor deterioration and maintaining printing quality.
Implementation Method 1
a charger configured to charge the photoconductor
Implementation Method 2
an overcurrent detector configured to output an overcurrent detection signal in response to detection of an overcurrent in the charger
Data Source
AI summary
An image forming apparatus, including: a photoconductor configured to be rotatable; a charger configured to charge the photoconductor; an overcurrent detector configured to output an overcurrent detection signal in response to detection of an overcurrent in the charger; and a controller, wherein the controller is configured to execute: an obtaining process of obtaining the overcurrent detection signal output from the overcurrent detector; a first counting process of counting a first number of detections based on the overcurrent detection signal obtained in the obtaining process, the first number of detections being the number of the overcurrent detection signals synchronized with a first cycle corresponding to one rotation of the photoconductor; and a first determining process of determining whether the first number of detections is not smaller than a first threshold which is not smaller than 2.