Registration Adjustment for Image Forming Apparatus
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Solution Overview
Problem
Conventional image forming apparatuses face challenges in accurately correcting color drift due to temperature changes, particularly within the optical scanning device, as existing methods primarily focus on external temperature measurements rather than internal temperature changes, leading to incomplete correction of image displacement.
Innovation Solution
The method involves using both a first temperature detecting unit near the polygon mirror and a second temperature detecting unit farther away to measure temperature changes, allowing for accurate registration adjustment by considering both temperature changes near the polygon mirror and internal ambient temperature changes within the image forming apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If only external temperature measurement is used for registration adjustment, then the device complexity is reduced, but the measurement precision and manufacturing precision of color drift correction deteriorate
Solution Approach 1:
The temperature detection system is segmented into multiple independent temperature detecting units positioned at different locations (near the polygon mirror and at other positions within the optical scanning device). Each unit measures local temperature changes, and the registration adjustment value integrates these segmented measurements to achieve comprehensive color drift correction, resolving the contradiction between system simplicity and correction precision.
2Measurement precision
If temperature detection is performed only near the polygon mirror, then the measurement precision for local temperature changes is improved, but the manufacturing precision of overall color drift correction deteriorates due to ignoring internal ambient temperature changes
Solution Approach 1:
The patent merges temperature detection results from multiple locations (near the polygon mirror and at other positions within the optical scanning device) into a unified registration adjustment value. This combination approach captures both local temperature changes near the polygon mirror and internal ambient temperature changes, achieving comprehensive color drift correction that addresses the contradiction between local measurement precision and overall correction precision.
3Device complexity
If fixed registration adjustment value is used, then the device complexity is reduced, but the manufacturing precision of image registration deteriorates due to temperature-induced position variations
Solution Approach 1:
The registration adjustment value transitions from a fixed parameter to a dynamic value that changes in response to temperature variations. By continuously monitoring temperature changes through multiple detecting units and adjusting the registration adjustment value accordingly, the system maintains high image registration precision under varying temperature conditions while managing system complexity through automated dynamic adjustment.
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 enables more precise correction of color drift by accounting for internal temperature variations, improving the accuracy of image registration and reducing image displacement, thereby enhancing the quality of color images.
Implementation Method 1
detecting a temperature near a polygon mirror that reflects and scans the laser light in the optical scanning device by using a first temperature detecting unit
Implementation Method 2
detecting a temperature at a location that is farther away from the polygon mirror than the first temperature detecting unit is by using a second temperature detecting unit
Implementation Method 3
when there is a change in the internal temperature of the LSU, the orientation of each mirror provided in the LSU changes
Data Source
AI summary
In a registration step, the temperature near a polygon mirror (83) is detected by a first temperature sensor (85), and the internal ambient temperature of an image forming apparatus (1) is detected by a second temperature sensor (86). Also, a registration adjustment value of each color is determined and stored in a memory (75). In a printing step, the registration adjustment value (A) of each color determined in the registration step is corrected based on a change in the temperature near the polygon mirror (83) and a change in the internal ambient temperature of the image forming apparatus (1). Furthermore, the write timing of an electrostatic latent image onto each photosensitive drum (13) by an optical scanning device (11) is controlled. Then, the position of the electrostatic latent image on each photosensitive drum (13) is shifted by an amount corresponding to the corrected registration adjustment value.