Photoconductor Drum Cycle Synchronization for Density Uniformity
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Solution Overview
Problem
Conventional electrophotographic image forming apparatuses face issues with density unevenness due to deviations in the cycle for correcting light intensity, which do not align with the cycle of change in density, leading to suboptimal image quality.
Innovation Solution
An image forming apparatus is designed with a photoconductor drum, optical scanner, cycle detector, density detector, measurer, generator, and adjuster to measure and adjust the correction cycle of light intensity, ensuring it matches the rotation cycle of the photoconductor drum, thereby minimizing deviations and improving density uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If exposure energy is adjusted to correct density unevenness, then density unevenness is decreased, but deviation with respect to starting position of writing latent image occurs
Solution Approach 1:
The patent applies preliminary action by establishing a standby time period before actual image formation. During this standby time, the system waits for the photoconductor drum to reach a predetermined position (indicated by the home position sensor) before initiating light emission. This preliminary positioning action ensures that even when exposure energy is adjusted for density correction, the starting position for writing the latent image remains accurate and consistent.
2Adaptability or versatility
If correction cycle for light intensity does not match rotation cycle of photoconductor drum, then correction can be applied, but density uniformity deteriorates
Solution Approach 1:
The patent applies dynamics by making the correction cycle adaptable to the actual rotation cycle of the photoconductor drum. The control unit dynamically adjusts the correction cycle based on feedback from the rotation cycle detector, ensuring that the correction timing synchronizes with the drum's rotation. This dynamic adjustment allows the system to maintain density uniformity while preserving correction functionality under varying operational conditions.
Solution Approach 2:
The patent implements feedback by using a rotation cycle detector to monitor the actual rotation cycle of the photoconductor drum and feeding this information back to the control unit. The control unit then adjusts the correction cycle based on this feedback, ensuring synchronization between the correction timing and the drum's rotation phase. This feedback mechanism maintains density uniformity while allowing flexible correction application.
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 reduces the deviation between the correction cycle for light intensity and the density change cycle, resulting in improved image quality by ensuring accurate and synchronized correction processes.
Implementation Method 1
an optical scanner, having a light source for emitting light to irradiate the photoconductor drum, configured to scan the photoconductor drum with the light to form a latent image on the photoconductor drum
Data Source
AI summary
An image forming apparatus includes: a photoconductor drum; an optical scanner, having a light source, configured to scan the photoconductor drum with light to form a latent image; a developer configured to develop an image, based on the latent image; a cycle detector configured to detect a rotation cycle of the photoconductor drum, to produce a cyclic signal indicative of the rotation cycle; a density detector configured to detect density of the image; a measurer configured to measure the rotation cycle at each rotation, based on the cyclic signal; a generator configured to generate, based on the density, a correcting value for correcting intensity of the light, the correcting value having a correction cycle based on a measurement result of the measurer; and an adjuster configured to adjust the correction cycle based on the rotation cycle measured at each rotation, so that the correction cycle matches the rotation cycle.