Scanning Optical Unit Light Path Length Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional scanning optical units have a long light path length in the incident optical system due to a small lateral magnification in the sub-scanning direction, which is undesirable.
Innovation Solution
A scanning optical unit is designed with a specific configuration that includes a coupling lens, an optical deflector with a reflecting surface, and a scanning optical system, where the light beam is converged on the reflecting surface in the sub-scanning direction, satisfying the conditions 0.01≤(βs/βm)²≤0.27 and βs²<1, to reduce the light path length and improve design flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the lateral magnification in the sub-scanning direction is small, then the scanning optical unit can achieve better image quality and reduced distortion, but the light path length of the incident optical system becomes longer
Solution Approach 1:
The patent applies parameter changes by optimizing the lateral magnification ratio (βs/βm)² to fall within the specific range of 0.01 to 0.27, and setting βs² < 1. This parameter optimization allows the system to achieve both short light path length and good image quality by finding the optimal balance point where the magnification is small enough to reduce distortion but not so small that it excessively lengthens the light path.
Solution Approach 2:
The patent addresses the light path length issue by introducing dimensional considerations in the optical layout. By carefully designing the spatial arrangement of optical components and utilizing the relationship between main scanning and sub-scanning directions, the system achieves compact light path configuration while maintaining the required magnification characteristics.
2Length of stationary object
If the light path length of the incident optical system is reduced, then the scanning optical unit becomes more compact and easier to manufacture, but the lateral magnification in the sub-scanning direction increases
Solution Approach 1:
The patent resolves this contradiction by establishing the optimal parameter range for (βs/βm)² between 0.01 and 0.27, and βs² < 1. These parameter constraints ensure that even with a reduced light path length, the lateral magnification remains controlled at appropriate levels to maintain image quality and minimize distortion.
3Length of stationary object
If the lateral magnification ratio (βs/βm)² is increased, then the light path length can be shortened, but the tolerance to manufacturing errors decreases
Solution Approach 1:
The patent identifies the optimal parameter range 0.01 ≤ (βs/βm)² ≤ 0.27 as the sweet spot that balances light path length reduction with maintaining sufficient tolerance to manufacturing errors. By keeping the magnification ratio within this range, the system achieves compact dimensions while remaining robust against manufacturing variations.
Solution Approach 2:
The patent incorporates design margins by setting conservative bounds on the magnification parameters. The constraints βs² < 1 and 0.01 ≤ (βs/βm)² ≤ 0.27 provide a cushion that anticipates manufacturing tolerances, ensuring that even with variations in component fabrication, the system maintains acceptable performance and image quality.
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 reduces the light path length of the incident optical system, allows for a more compact design, and enhances the tolerance to manufacturing errors, making the scanning optical unit more efficient and easier to manufacture.
Implementation Method 1
light emitted from a light source is collimated into a light beam with a collimating lens
Implementation Method 2
this light beam is deflected in a main scanning direction by rotating reflecting surfaces of an optical deflector
Implementation Method 3
the deflected light beam is focused on a photoconductor drum through a scanning lens
Implementation Method 4
An incident optical system provided between the light source and reflecting surfaces of the optical deflector causes the light beam to converge in a sub-scanning direction
Data Source
AI summary
Scanning optical unit includes: light source; incident optical system including one coupling lens for converting light from the light source into a light beam; optical deflector having a reflecting surface and configured to reflect and deflect the light beam in main scanning direction; and scanning optical system for focusing the deflected light beam on an image surface. The incident optical system converges the light beam on the reflecting surface in sub-scanning direction. Further, 0.01≤(βs/βm)2≤0.27 and βs2<1 are satisfied, where βm is a lateral magnification of the entire optical system from the light source to the image surface in the main scanning direction, βs is a lateral magnification of the entire optical system in the sub-scanning direction, and βs2 is a lateral magnification of the scanning optical system from the reflecting surface of the optical deflector to the image surface in the sub-scanning direction.