Rotating Imaging Unit for Compact Image Reading Apparatus
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Solution Overview
Problem
Conventional image reading apparatuses face challenges in maintaining a consistent optical path length and depth of field when reading media from the upper side in the vertical direction, leading to increased apparatus size and depth of field requirements.
Innovation Solution
The image reading apparatus incorporates a rotation unit that rotates around a rotation axis, with the imaging unit positioned radially outward, allowing it to image media placed on a placement surface below, while the light source irradiates the media with light, thereby reducing the change in optical path length and depth of field without increasing the apparatus size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the imaging unit is provided at a high height position to reduce the depth of field, then the depth of field is reduced, but the size of the apparatus is increased
Solution Approach 1:
The imaging unit is made rotatable around a rotation axis, transforming it from a static high-positioned component to a dynamic one that can change its position and orientation. This allows the system to achieve a reduced depth of field through controlled movement rather than relying solely on a fixed high height, thereby avoiding the apparatus size increase.
Solution Approach 2:
Instead of solving the depth of field issue by moving the imaging unit vertically (one dimension), the patent introduces rotation around an axis, adding a angular dimension to the positioning. This dimensional change allows the imaging unit to scan across the medium while maintaining optimal optical path length, resolving the contradiction between depth of field control and apparatus size.
2Stability of the object's composition
If the imaging unit is provided at a high height position to reduce the depth of field, then the depth of field is reduced, but the optical path length becomes non-constant
Solution Approach 1:
The rotatable imaging unit dynamically adjusts its position relative to the medium during the scanning process. By rotating around the rotation axis, the imaging unit maintains a consistent optical path length throughout the scanning motion, eliminating the non-constant optical path length problem that would otherwise occur with a fixed high-positioned setup.
3Stability of the object's composition
If the imaging unit is provided at a high height position to reduce the depth of field, then the depth of field is reduced, but the change in optical path length increases
Solution Approach 1:
The rotatable configuration enables the imaging unit to dynamically compensate for changes in optical path length during scanning. The rotation mechanism ensures that the optical path length remains substantially constant throughout the scanning process, maintaining manufacturing precision and image quality while achieving reduced depth of field.
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 effectively suppresses the change in optical path length and depth of field, allowing for a more compact design while maintaining high image quality and resolution.
Implementation Method 1
a light source configured to irradiate the medium with light
Implementation Method 2
document image reading means (an imaging unit) provided on an upper portion of the support arm for reading a document image by the light beam reflected from the document surface
Data Source
AI summary
An image reading apparatus includes a main body, a rotation unit supported on the main body so as to be rotatable around a rotation axis, an imaging unit that is mounted on the rotation unit at an outward position in a radial direction of the rotation axis and images a medium to be read that is placed on a placement surface located under the rotation unit in the vertical direction, and a light source that irradiates the medium to be read with light. The light source and the imaging unit can be arranged with a relative positional relationship capable of suppressing specular reflected light of light that is emitted from the light source and reflected by the medium to be read from being incident on the imaging unit.