Image Forming Apparatus Density and Gradation Adjustment
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Solution Overview
Problem
Existing image forming apparatuses face challenges in simultaneously adjusting desired density and gradation accurately without burdening the user, as separate density and gradation adjustments are often cumbersome and require manual intervention, especially in maintaining linearity amidst environmental changes.
Innovation Solution
An image forming apparatus with integrated density and gradation adjustment units that use a scanner, photoconductors, charging, exposure, and development units to form test patterns, detect densities, and update correction data, allowing for simultaneous and automatic adjustments of process parameters to maintain desired image quality across varying conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate density adjustment and gradation adjustment functions are provided, then density and gradation can be adjusted independently, but the operation becomes cumbersome and requires user intervention
Solution Approach 1:
The patent combines separate density adjustment and gradation adjustment functions into a single integrated adjustment process. The density adjustment unit and gradation adjustment unit work together using the same test pattern and sensor data, eliminating the need for separate user operations while maintaining independent control over both density and gradation parameters.
Solution Approach 2:
The system performs automatic density and gradation adjustments using built-in sensors and processing units without requiring user intervention. The image forming apparatus independently detects test pattern densities, calculates required adjustments, and updates correction tables automatically, making the complex adjustment process self-service.
2Manufacturing precision
If manual gradation test pattern printing and scanning is required, then gradation correction table can be updated, but the work is troublesome for normal users
Solution Approach 1:
The patent replaces the manual mechanical process of printing test patterns on paper and scanning them with an automatic optical detection system. The image forming apparatus uses its own sensors to detect test patterns formed directly on the transfer body, eliminating the need for paper-based manual testing and scanning operations.
Solution Approach 2:
The system automatically performs gradation measurement and correction table updates using built-in sensors and processing units. The apparatus independently forms test patterns, detects their densities, calculates correction values, and updates the gradation correction table without requiring user operations, making the process self-service.
3Measurement precision
If only maximum density adjustment is performed, then the maximum gradation value can be optimized, but intermediate density linearity cannot be maintained
Solution Approach 1:
The patent segments the gradation measurement into multiple density levels rather than measuring only the maximum density. The system measures densities at multiple gradation levels (including intermediate densities) and uses these segmented measurements to comprehensively update the gradation correction table, ensuring both maximum density accuracy and intermediate density linearity.
Solution Approach 2:
The system changes the measurement parameters by detecting densities at multiple gradation levels rather than a single maximum level. This parameter change enables comprehensive correction of the gradation correction table across the entire density range, maintaining both maximum density accuracy and intermediate density linearity through multi-parameter optimization.
4Measurement precision
If density and gradation adjustments are performed separately, then each can be optimized independently, but simultaneous accuracy cannot be achieved
Solution Approach 1:
The patent merges density adjustment and gradation adjustment into a single integrated process that simultaneously optimizes both parameters. The system uses the same test pattern and sensor measurements for both adjustment types, coordinating the density adjustment unit and gradation adjustment unit to achieve simultaneous accuracy rather than sequential optimization.
Solution Approach 2:
The system changes from separate single-parameter optimization to simultaneous multi-parameter optimization. By measuring multiple density levels and coordinating adjustments across both density and gradation parameters together, the system achieves simultaneous accuracy for both parameters through integrated multi-parameter 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
Enables accurate and simultaneous adjustment of density and gradation without user intervention, maintaining optimal image quality despite changes in ambient conditions or operating time, thereby simplifying maintenance and improving print consistency.
Implementation Method 1
a scanner that reads a document and generates image data
Implementation Method 2
a sensor that detects a density of an image formed on the transfer body
Data Source
AI summary
An image forming apparatus that forms a color image includes: a sensor that detects a density of an image formed on the transfer body; a density adjusting unit that forms a density test pattern on a transfer body and that adjusts process parameters such that a density of the density test pattern on the transfer body falls within a predetermined range of a reference density; and a gradation adjusting unit that forms a gradation test pattern on the transfer body and updates the gradation correction data such that a density for every gradation of the gradation test pattern on the transfer body falls within a predetermined range of a reference gradation density acquired and stored beforehand. The gradation adjusting unit updates the gradation correction data subsequently after the density adjusting unit adjusts the density of the density test pattern.