Image Density Correction Timing Using Toner Charge Prediction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image density correction in electrophotographic image forming apparatuses is often performed at non-optimal timings due to variations in environment and printing conditions, leading to inconsistent image quality and inefficient toner consumption.
Innovation Solution
An image forming apparatus that includes an image density sensor and control portion to predict toner charge amount and determine the timing of image density correction based on the rate of change of toner charge amount, adjusting development voltage and exposure to maintain optimal image density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If image density correction is performed at predetermined intervals based on design data, then the correction can be performed regularly and systematically, but the correction timing becomes non-optimal due to variations in environment and printing conditions
Solution Approach 1:
The system uses an image density sensor to detect actual image density and feeds this information back to the control portion. The control portion calculates toner charge amount based on detected density and compares it with reference values, then adjusts correction timing accordingly. This closed-loop feedback mechanism replaces fixed intervals with dynamic, condition-based timing.
Solution Approach 2:
The correction interval is transformed from a static predetermined value to a dynamic parameter that adapts to changing conditions. The control portion continuously monitors toner charge amount trends and adjusts the timing of image density correction based on the rate of change, making the system responsive to environmental and printing condition variations.
2Reliability
If image density correction is performed frequently to maintain optimal image density, then image quality can be maintained, but toner consumption increases due to unnecessary corrections
Solution Approach 1:
The system monitors actual image density and toner charge amount through the image density sensor, providing feedback to determine whether correction is truly needed. This prevents unnecessary corrections and associated toner consumption while maintaining image quality when needed.
Solution Approach 2:
The system changes the parameter of correction timing from fixed intervals to variable intervals based on toner charge amount trends. By calculating the rate of change and comparing with thresholds, the system adjusts correction frequency dynamically, reducing unnecessary corrections and toner waste.
3Loss of substance
If image density correction is performed less frequently to reduce toner consumption, then toner efficiency improves, but image density stability deteriorates leading to defective images
Solution Approach 1:
The feedback mechanism continuously monitors image density and toner charge amount, enabling the system to perform correction only when actual degradation is detected. This ensures image quality is maintained while avoiding unnecessary corrections that would waste toner.
Solution Approach 2:
The system performs preliminary detection of toner charge amount trends and predicts when correction will be needed. By monitoring the rate of change and comparing with reference values, the system prepares for correction at the optimal moment, preventing defective images before they occur while minimizing unnecessary interventions.
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 ensures accurate and timely image density correction, preventing defective images and reducing unnecessary toner consumption by aligning correction intervals with toner charge variations, thus enhancing image quality and efficiency.
Implementation Method 1
a charging device that charges the surface of the image carrier
Implementation Method 2
The exposure device forms the electrostatic latent image with an attenuated electric charge by exposing to light the surface of the image carrier charged by the charging device
Implementation Method 3
a development device that has a developer carrier carrying developer including toner and that develops an electrostatic latent image formed on the image carrier into a toner image
Data Source
AI summary
An image forming apparatus includes an image forming portion, an exposure device, an image density sensor, and a control portion. The control portion can, by adjusting the development voltage based on the image density of a reference image and the amount of exposure from the exposure device, perform image density correction to adjust the image density. The control portion predicts the toner charge amount based on a formation condition of the reference image and the image density of the reference image and determines the timing of performing the image density correction next time based on the rate of change of the toner charge amount calculated using a first toner charge amount predicted when the image density correction was performed last time, a second toner charge amount predicted when the image density correction is performed this time, and the interval between the image density correction performed last time and this time.