Image Position Correction for Laser Printer Density Uniformity
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Solution Overview
Problem
Existing image forming apparatuses face challenges in directly addressing uneven intervals between line images, leading to density unevenness, which previous methods like reverse density correction cannot fully resolve.
Innovation Solution
An image forming apparatus with a rotatable photosensitive member, a light emission unit, and a transfer unit, equipped with an acquisition unit for variable speed information and an image position correction unit to adjust image positions based on acquired speed data, ensuring uniform line image intervals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If reverse density correction control is applied to correct density unevenness, then image density uniformity is improved, but the underlying problem of uneven line image intervals caused by photosensitive member rotation speed variation is not resolved
Solution Approach 1:
The patent applies preliminary action by correcting image position before image formation. The image position correction unit adjusts the image position based on the rotation speed of the photosensitive member before the electrostatic latent image is formed, thereby preventing uneven line image intervals from occurring in the first place, rather than correcting density unevenness after it has occurred.
Solution Approach 2:
The patent implements feedback by using the detected rotation speed information of the photosensitive member to dynamically adjust the image position. The image position correction unit receives feedback about rotation speed variations and automatically compensates for them by adjusting the image position accordingly, creating a closed-loop control system.
2Productivity
If the rotation speed of the photosensitive member varies, then image formation speed is improved, but uneven intervals between line images occur causing density unevenness
Solution Approach 1:
The patent applies dynamics by making the image position adjustable and adaptable to changing rotation speeds. The image position correction unit dynamically adjusts the image position based on the actual rotation speed of the photosensitive member, allowing the system to maintain precise line image intervals even when rotation speed varies during operation.
Solution Approach 2:
The patent implements parameter changes by modifying the image position parameter in response to rotation speed variations. When the rotation speed changes, the image position correction unit changes the image position parameter to compensate, thereby maintaining uniform line image intervals despite speed fluctuations.
3Manufacturing precision
If image position correction based on rotation speed is applied, then line image interval uniformity is improved, but system complexity increases due to additional acquisition and correction units
Solution Approach 1:
The patent applies universality by designing the image position correction unit to perform multiple functions. It not only corrects image position based on rotation speed but also integrates with the existing image formation system, serving both as a speed compensation mechanism and a position control unit, thereby reducing the need for separate dedicated components.
Solution Approach 2:
The patent uses an intermediary approach by introducing the image position correction unit as a mediator between the rotation speed detection and the image formation process. This intermediary component translates rotation speed information into position adjustments, bridging the gap between speed control and position precision without requiring direct complex interaction between all system components.
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 solution effectively corrects image position discrepancies caused by variable rotation speeds, directly addressing the issue of uneven line image intervals and improving overall image quality by preventing density unevenness.
Implementation Method 1
a rotatable photosensitive member
Implementation Method 2
a light emission unit configured to emit a laser beam to the photosensitive member based on image information
Implementation Method 3
a transfer unit configured to transfer a toner image developed on the photosensitive member by the laser beam emitted by the light emission unit onto a member to be transferred
Data Source
AI summary
An image forming apparatus is capable of more directly solving a problem of unevenly formed line images. The image forming apparatus includes a rotatable photosensitive member, a light emission unit configured to emit a laser beam based on image information, and a transfer unit configured to transfer a toner image developed on the photosensitive member. The image forming apparatus acquires variable speed information, which indicates a variable rotation speed of the photosensitive member. In addition, the image forming apparatus executes image position correction on the image information based on the acquired variable speed information.