Mirror Arrangement for Compact Image Reader Optical Path
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Solution Overview
Problem
Existing image reading devices have an unbalanced arrangement of mirrors, leading to increased size and optical path variations, making them larger and less efficient.
Innovation Solution
The mirrors are positioned on both sides of an imaginary line extending along the optical axis, with downstream mirrors closer to the document and the imaginary line than upstream mirrors, allowing for a well-balanced arrangement and reduced device size, while preventing vignetting and allowing for the use of a reduction-type optical system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If mirrors are arranged in a conventional unbalanced manner, then the optical path can be simplified, but the image reader size increases and optical balance deteriorates
Solution Approach 1:
The patent applies asymmetry by arranging mirrors in a balanced configuration where downstream mirrors are positioned closer to the optical axis than upstream mirrors. This asymmetric arrangement within a symmetric framework achieves optimal optical path balance, preventing vignetting while maintaining a compact image reader structure.
Solution Approach 2:
The patent utilizes three-dimensional spatial arrangement by positioning mirrors at different distances from the optical axis and at different longitudinal positions. This dimensional optimization allows the light beam to be efficiently guided through the optical system without vignetting, achieving both compact size and balanced optical paths.
2Volume of stationary object
If mirrors are arranged in a well-balanced manner, then the image reader size is reduced, but the arrangement complexity increases
Solution Approach 1:
The patent segments the mirror arrangement into distinct groups: upstream mirrors positioned farther from the optical axis and downstream mirrors positioned closer. This segmentation creates a modular, systematic configuration that achieves balanced optical paths while maintaining manageable structural complexity.
Solution Approach 2:
The patent applies local quality by assigning different positional characteristics to different mirrors based on their function. Upstream mirrors are positioned for light collection, while downstream mirrors are positioned for precise beam guidance, optimizing each mirror's location for its specific role in the optical system.
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 size of the image reader and image reading device, maintains optical balance, and prevents vignetting, resulting in a more compact and efficient imaging system.
Implementation Method 1
light reflected by a document is reflected multiple times by using one mirror
Implementation Method 2
The image reader includes a scanning body in which at least a plurality of mirrors, a condenser lens, and an image sensor are disposed
Data Source
AI summary
An image reading device includes an image reader that scans a document so as to read an image of the document. The image reader includes a scanning body in which at least plural mirrors, a condenser lens, and an image sensor are disposed. In the scanning body, concerning positional relationships among the plural mirrors as viewed from a main scanning direction, the plural mirrors are disposed on two sides with respect to an imaginary line extending along an optical axis of reflected light from the document. The mirrors on a corresponding one of the two sides are disposed such that a reflecting position of a mirror on a downstream side in a traveling direction of the reflected light is positioned closer to the document and also to the imaginary line than that of a mirror on an upstream side in the traveling direction of the reflected light.