Optical Scanning Unit Scan Line Inclination Control
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Solution Overview
Problem
Conventional optical scanning units face challenges in maintaining scan line alignment during changes in the ratio between the linear velocity of an image carrier and the scan speed, leading to image inclination issues, especially when printing on thick or colored papers, which affects printing speed and image quality.
Innovation Solution
An optical scanning unit with a light emitter, rotary deflector, and controller that adjusts the inclination of the scan line by changing the ratio between the linear velocity of the image carrier and the scan speed, using a multi-beam system and inclination adjustment mechanisms to maintain alignment, even at reduced linear velocities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the linear velocity of the photoconductor is reduced for thick-sheet printing or full-color printing, then the heat amount per unit time is increased to secure stable fixing performance, but the rotation speed of the rotary deflector is significantly lowered below the optimal range, worsening low-frequency jitter or uneven rotation and generating image failures
Solution Approach 1:
The patent applies dynamics by making the number of light beams variable rather than fixed. The controller dynamically adjusts the number of light beams based on the linear velocity of the photoconductor, ensuring that the rotary deflector operates within its optimal rotation speed range even when printing on thick sheets or in full-color mode, thereby preventing low-frequency jitter and image failures while maintaining stable fixing performance
Solution Approach 2:
The patent changes the parameter of light beam quantity from a constant value to a variable value that depends on linear velocity. By reducing the number of light beams when linear velocity is reduced, the system maintains the rotation speed of the rotary deflector within the optimal range, avoiding the harmful effects of operating below the optimal speed while still providing sufficient heat for fixing
2Reliability
If the number of light beams is reduced when linear velocity is reduced, then the rotation speed of the rotary deflector is maintained within the optimal range, but the scan line inclination increases due to the changed ratio between linear velocity and scan speed
Solution Approach 1:
The patent implements feedback by using the controller to monitor the linear velocity of the photoconductor and accordingly adjust the number of light beams. This feedback mechanism ensures that the rotation speed of the rotary deflector remains within the optimal range while compensating for the scan line inclination issue through coordinated control of scanning parameters
Solution Approach 2:
The patent applies dynamics by making the number of light beams variable rather than fixed. The controller dynamically adjusts the number of light beams based on the linear velocity of the photoconductor, ensuring that the rotary deflector operates within its optimal rotation speed range even when printing on thick sheets or in full-color mode, thereby preventing low-frequency jitter and image failures while maintaining stable fixing performance
3Productivity
If the linear velocity of the photoconductor is increased for high-speed printing, then the printing speed is improved, but the heat amount per unit time is reduced, compromising fixing performance on thick or colored papers
Solution Approach 1:
The patent applies dynamics by making the number of light beams variable rather than fixed. The controller dynamically adjusts the number of light beams based on the linear velocity of the photoconductor, ensuring that the rotary deflector operates within its optimal rotation speed range even when printing on thick sheets or in full-color mode, thereby preventing low-frequency jitter and image failures while maintaining stable fixing performance
Solution Approach 2:
The patent changes the parameter of light beam quantity from a constant value to a variable value that depends on linear velocity. By reducing the number of light beams when linear velocity is reduced, the system maintains the rotation speed of the rotary deflector within the optimal range, avoiding the harmful effects of operating below the optimal speed while still providing sufficient heat for fixing
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 suppresses scan line inclination, ensuring stable and high-quality image formation across various paper types and colors by maintaining optimal rotation speeds and light beam alignment, thereby improving printing efficiency and reducing image failures.
Implementation Method 1
a light emitter, a rotary deflector, an inclination adjustment unit, and a controller. The light emitter emits a light beam
Implementation Method 2
The rotary deflector deflects and scans the light beam, emitted from the light emitter, onto a surface of the latent image carrier
Data Source
AI summary
An optical scanning unit used in an image forming apparatus having a latent image carrier includes a light emitter, a rotary deflector, an inclination adjustment unit, and a controller. The light emitter emits a light beam. The rotary deflector deflects and scans the light beam onto a surface of the latent image carrier. The inclination adjustment unit adjusts an inclination of a scan line corresponding to the light beam relative to a reference scan line on the latent image carrier. The controller changes at least one of a linear velocity of the latent image carrier and a rotation speed of the rotary deflector so as to change a ratio between the linear velocity of the latent image carrier and a scan speed of the light beam, and controls the inclination adjustment unit based on the ratio to keep the scan line from inclining relative to the reference scan line.