Optical Writing Apparatus Magnifying Power Control
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Solution Overview
Problem
Existing optical writing devices face challenges in maintaining image quality due to changes in magnifying power during adjustments in the sub-scanning direction, which affect the main scanning direction, leading to processing load and time inefficiencies in controlling the write clock frequency and light deflector speed.
Innovation Solution
The optical writing device incorporates a write clock frequency controller and a light-deflector controller to independently manage the write clock frequency and light deflector speed based on image magnifying-power information, ensuring a target number of clock pulses over a prescribed distance in the main scanning direction, even when the light deflector's speed is changed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the light deflector speed is changed to adjust magnifying power in the sub-scanning direction, then the magnifying power adjustment is achieved, but the number of clock pulses varies causing image distortion in the main scanning direction
Solution Approach 1:
The patent implements a feedback control mechanism where the actual number of clock pulses during the light deflector rotation period is measured and compared against a target value. The write clock frequency is then adjusted based on this comparison to maintain the target number of pulses, thereby preventing image distortion while allowing magnifying power adjustment.
Solution Approach 2:
The patent dynamically adjusts the write clock frequency parameter in response to changes in light deflector speed. By changing the clock frequency parameter to compensate for speed variations, the system maintains a constant number of clock pulses per rotation period, ensuring consistent image quality across different magnifying power settings.
2Manufacturing precision
If the write clock frequency is controlled to maintain target number of pulses, then image quality is maintained, but processing load increases due to frequency adjustment calculations
Solution Approach 1:
The patent pre-calculates and stores the relationship between light deflector rotation periods and target clock pulse numbers in a lookup table. During operation, the system simply retrieves the appropriate target value from this pre-computed table based on the current rotation period, avoiding complex real-time calculations and reducing processing load while maintaining image quality.
3Adaptability or versatility
If manual control methods are used for coordinate transformation and magnification correction, then flexibility is maintained, but processing time increases
Solution Approach 1:
The patent replaces manual coordinate transformation and magnification correction operations with automated light deflector speed control and write clock frequency adjustment. This substitution of manual mechanical control with automated electronic control significantly reduces processing time while maintaining the flexibility to adjust magnifying power through electronic parameters.
Data Source
AI summary
An optical writing device, and a method of controlling the optical writing device. The optical writing device and the method includes controlling speed of operation of a light deflector based on image magnifying-power information in a sub-scanning direction parallel to a direction in which a surface of a photoconductor moves, and controlling a prescribed write clock frequency such that a number of clock pulses of write light will become a target number of pulses over a period where the write light scans an area within a prescribed distance in a main scanning direction, the target number of pulses being maintained even when the speed of operation of the light deflector is changed in the controlling the speed of operation of the light deflector. The write clock frequency controller maintains the target number of pulses even when the speed of operation of the light deflector is changed by the light-deflector controller.