Optical Scanning Apparatus with Tilted Light Sources
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Solution Overview
Problem
Existing optical scanning apparatuses for color laser printers and copiers face challenges in achieving high image quality and cost reduction due to issues with scan line bending, wavefront aberration, and increased component count, particularly in tandem type configurations with oblique entrance optical systems.
Innovation Solution
The apparatus integrates multiple light sources with different sub-scanning angles, applied to a common surface of a polygon mirror, reducing the number of components and oblique entrance angles, which allows for a compact design and improved image quality by minimizing wavefront aberration and scan line bending.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If an oblique entrance optical system is used to reduce the number of components and apparatus size, then device complexity and volume are reduced, but scan line bending and wavefront aberration increase, degrading image quality
Solution Approach 1:
The patent applies parameter changes by precisely controlling the oblique entrance angle (α) to be 15 degrees or less, and the light source position (Xs) to be within specific ranges (0.05 ≤ Xs ≤ 0.15 for f-number 2.0, 0.03 ≤ Xs ≤ 0.10 for f-number 1.8). These parameter optimizations balance component reduction with maintaining image quality by minimizing scan line bending and wavefront aberration within acceptable limits.
2Manufacturing precision
If the light source is positioned to reduce the oblique entrance angle, then wavefront aberration decreases, but the light path length increases, resulting in larger apparatus size
Solution Approach 1:
The patent optimizes the light source position parameter (Xs) to achieve the best compromise between wavefront aberration and apparatus size. By setting Xs within specific ranges depending on the f-number, the system minimizes wavefront aberration while keeping the light path length and overall apparatus volume within acceptable limits for practical applications.
3Device complexity
If multiple light sources are applied to a common surface of the polygon mirror, then the number of components is reduced, but the oblique entrance angle increases, causing scan line bending
Solution Approach 1:
The patent controls the oblique entrance angle (α) to be 15 degrees or less when multiple light sources are applied to a common surface of the polygon mirror. This parameter control minimizes scan line bending and maintains good linearity in the scanned image, while still achieving component reduction through the single-sided scanning configuration.
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 configuration results in a cost-effective, compact optical scanning apparatus that maintains high image quality by reducing the number of components and minimizing wavefront aberration, achieving stable beam spots and efficient image formation.
Implementation Method 1
a deflecting part deflecting light beams from the plurality of light sources
Implementation Method 2
coupling lenses corresponding thereto respectively
Data Source
AI summary
A light source part has a light source unit in which the plurality of light sources respectively emitting the light beams at angles different in a sub-scanning direction with respect to an optical standard plane, parallel to a main scanning direction and passing through a standard axis of a surface shape of a lens of the imaging part, which lens is closest to the deflecting part, and applied to the deflecting part at angles different in the sub-scanning direction, are integrally provided; and the plurality of light sources are inclined so that the plurality of light sources thus respectively emit the light beams at the angles different in the sub-scanning direction with respect to the optical standard plane.