Image Density Control Method for Multi-Speed Printers
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Solution Overview
Problem
Conventional image forming apparatuses require extensive time for density control processes, especially when switching between multiple image forming speeds, due to the need for repeated measurements and adjustments in toner density, leading to inefficiencies in image production.
Innovation Solution
A density control method that sets a reference speed for maximum density control and gradation control, allowing for quick measurements and adjustments, and then applies these settings to other speeds, enabling rapid image density correction across multiple speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If maximum density control process and density gradation control process are carried out at all image forming speeds, then image density accuracy is improved, but control time is significantly increased
Solution Approach 1:
The patent applies preliminary action by performing maximum density control and density gradation control at reference speed first, then using these pre-obtained characteristics to determine control parameters for other speeds through calculation rather than repeated measurements. This eliminates the need to perform full control processes at every speed level.
Solution Approach 2:
The patent changes the approach from physically performing control processes at all speeds to calculating control parameters based on reference speed characteristics. By deriving speed-specific parameters (Vcont, Vgamma, Vgamma2) from reference speed measurements through mathematical relationships, the system achieves multi-speed density control without repeated physical measurements.
2Manufacturing precision
If density control processes are repeated when switching between multiple image forming speeds, then density accuracy at each speed is improved, but productivity is reduced
Solution Approach 1:
The patent makes the reference speed control characteristics universal by using them to determine control parameters for all other speeds. The characteristics obtained at reference speed serve multiple purposes: they provide the basis for calculating Vcont, Vgamma, and Vgamma2 parameters that apply to both high-speed and low-speed operation, eliminating the need for separate control processes at each speed.
Solution Approach 2:
The patent creates a mathematical model that copies the reference speed characteristics to other speeds. By calculating speed-specific parameters based on reference speed measurements through established relationships, the system reproduces accurate density control at different speeds without physically repeating the entire control process.
3Reliability
If extensive measurements and adjustments are performed for each image forming speed, then toner density stability is improved, but the time required for image production increases
Solution Approach 1:
The patent implements feedback by measuring density characteristics at reference speed and using these measurements to calculate and adjust control parameters for other speeds. The measured density values (Vcont, Vgamma) provide feedback that feeds into mathematical models to determine appropriate exposure and development conditions for different speeds, ensuring stability without repeated measurements.
Data Source
AI summary
There is provided an image forming apparatus which is capable of quickly performing measurements required for obtaining a proper image density. The image forming apparatus having a plurality of image forming apparatuses performs an image density adjustment control process by carrying out a maximum density control process at a reference image forming speed, and carrying out a density gradation control process at each of the plurality of image forming speeds. Image forming conditions for carrying out the density gradation control process at speeds other than the reference image forming speed are determined by performing operation on image forming conditions determined by the maximum density control process carried out at the reference image forming speed.