Image Forming Apparatus Calibration via Feedback Control
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Solution Overview
Problem
Electrophotographic image forming apparatuses face instability issues due to the re-transfer phenomenon, leading to variations in image density and color, especially in mixed-color images, despite controlled image forming conditions, resulting in potential downtime for calibration adjustments.
Innovation Solution
An image forming apparatus with a converting unit for image data conversion, multiple image forming units for different colors, a scanning unit for pattern image analysis, and a controller to determine and execute calibration conditions based on measurement results to adjust image forming conditions and generate conversion conditions for target color and density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If calibration is executed frequently to maintain color accuracy in mixed-color images, then color precision is improved, but device downtime increases
Solution Approach 1:
The system implements feedback by measuring the actual color values of test images and comparing them with target values. Based on this feedback, the system determines whether calibration is necessary and adjusts image forming conditions accordingly, avoiding unnecessary calibration operations and reducing downtime while maintaining color accuracy.
Solution Approach 2:
The system changes operational parameters dynamically by adjusting image forming conditions (such as developing agent charge amount, transfer voltage, or exposure conditions) based on measured color deviations. This allows the system to correct color accuracy issues without performing full calibration procedures, thereby reducing downtime while maintaining precision.
2Manufacturing precision
If image forming conditions are controlled based on monochromatic test images, then density control is improved, but color accuracy in mixed-color images deteriorates due to re-transfer phenomenon
Solution Approach 1:
The system segments the calibration process into two distinct parts: monochromatic calibration for density control and color calibration for color accuracy. By separating these functions, the system can optimize each aspect independently - using monochromatic test images for density control while using color test images to detect and correct re-transfer phenomenon effects on color accuracy.
Solution Approach 2:
The system introduces color test images as an intermediary element that specifically detects the re-transfer phenomenon's impact on color accuracy. These intermediary measurements provide additional information that bridges the gap between monochromatic density control and actual color output, enabling separate optimization of both density and color accuracy.
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 solution reduces downtime by determining the necessity of color calibration for mixed-color images, ensuring accurate target color and density, thereby improving the stability and efficiency of the image forming process.
Implementation Method 1
a photosensitive member is electrostatically charged and is exposed to form an electrostatic latent image
Implementation Method 2
the photosensitive member is electrostatically charged and is exposed to form an electrostatic latent image
Implementation Method 3
yellow, magenta, cyan, and black images are transferred one upon another to an intermediate transfer member to form a full-color image
Implementation Method 4
when the charge polarity of a developing agent transferred to the intermediate transfer member is reversed, the developing agent having the opposite polarity may unintentionally be transferred from the intermediate transfer member to the photosensitive member
Data Source
AI summary
An image forming apparatus includes a converting unit, a plurality of image forming units, a scanning unit, a first generating unit, a second generating unit, an intermediate transfer member, a measuring unit, and a controller configured to, after the first generating unit generates an image forming condition, control the plurality of image forming units to form a measurement image, control the measuring unit to measure the measurement image, and control whether to control the second generating unit to generate a conversion condition or not on the basis of a result of the measurement performed on a previous measurement image and a result of the measurement performed on a current measurement image.