Image Forming Apparatus Toner Charge Feedback Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electrophotographic image forming apparatuses face challenges in controlling developer charge amounts, leading to inconsistent image densities due to excessive charging during low toner consumption, requiring effective methods to adjust and maintain target charge levels.
Innovation Solution
An image forming apparatus with a controller that forms measuring images to measure toner discharge and adjust conversion conditions, using feedback loops to correct toner charge levels by forming pattern images for discharge and supplying new toner, thereby maintaining desired image densities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the image forming apparatus forms images at low toner consumption, then toner saving is improved, but the developer charge amount becomes excessively high
Solution Approach 1:
The control unit monitors the charge amount of developer and uses feedback control to adjust the development bias voltage. When the charge amount exceeds the target value, the system automatically reduces the development bias voltage to bring the charge amount back to the target level, preventing excessive charging during low toner consumption operations
Solution Approach 2:
The development bias voltage is dynamically adjusted based on the actual charge amount of developer. The system transitions from a fixed bias voltage to a variable bias voltage that responds to real-time charge conditions, allowing the apparatus to adapt to changing toner consumption patterns and maintain optimal charge levels
2Quantity of substance
If the developer charge amount is increased, then the density of formed image becomes lower, but image density control precision deteriorates
Solution Approach 1:
The system uses feedback control where the control unit measures the actual charge amount of developer and adjusts the development bias voltage accordingly. This closed-loop control ensures that the image density remains within the desired range by continuously correcting deviations caused by varying charge amounts
Solution Approach 2:
The system changes the development bias voltage parameter in response to changes in developer charge amount. By adjusting this critical parameter dynamically, the system compensates for the inverse relationship between charge amount and image density, maintaining consistent image quality across different operating conditions
3Manufacturing precision
If the charge amount of developer is controlled to target value, then image density is improved, but device complexity increases due to additional control mechanisms
Solution Approach 1:
The control unit incorporates a feedback mechanism that monitors developer charge amount and automatically adjusts development bias voltage. This feedback control enables precise image density control while keeping the overall system design relatively simple by using standard sensing and control circuits
Solution Approach 2:
The system performs self-regulation of developer charge amount through automatic feedback control. The control unit autonomously adjusts the development bias voltage without requiring external intervention, simplifying operation while maintaining precise density 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 apparatus effectively controls image density by continuously monitoring and adjusting toner charge levels, ensuring consistent image formation even during low toner consumption, minimizing downtime and maintaining desired image quality.
Implementation Method 1
a measurement unit configured to measure a measuring image formed on the image bearing member by the image forming unit
Implementation Method 2
An electrophotographic image forming apparatus forms an electrostatic latent image on a photosensitive member based on image data
Implementation Method 3
The development device frictionally charges the developer in the development device to thereby change the charge amount of the developer
Implementation Method 4
a controller configured to perform toner discharge processing by performing control to cause the image forming unit to discharge the toner in the container therefrom
Data Source
AI summary
An image forming apparatus includes a conversion unit that converts image data based on a conversion condition, an image forming unit that forms an image based on the converted image data, a measurement unit that measures a measuring image, and a generation unit that controls the image forming unit to form a first measuring image while the image forming unit is continuously forming images, and generates the conversion condition based on first measurement data of the first measuring image and a first feedback condition. The generation unit controls the image forming unit to form a second measuring image during a period from when toner discharge processing has been performed until the image forming unit forms a subsequent image, and generates the conversion condition based on second measurement data of the second measuring image, and a second feedback condition with a larger correction amount than the first feedback condition.