Rotating Light Source Switching Optical Paths for Document Reading
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing reading apparatuses face challenges in efficiently capturing both specularly and diffusely reflected light from documents using a single light source, often requiring complex optical systems and multiple irradiation angles to achieve accurate image reading.
Innovation Solution
A reading apparatus with a rotating irradiation unit that switches between two optical paths, one for specularly reflected light and another for diffusely reflected light, using a single light source and a common optical path to guide reflected light to a sensor, allowing for efficient capture of both types of reflections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single light source is used to read both specularly and diffusely reflected light, then the device complexity is reduced, but it becomes difficult to efficiently capture both types of reflected light simultaneously
Solution Approach 1:
The light source is made rotatable to dynamically change its irradiation angle. By rotating the light source between a first angle (for specular reflection) and a second angle (for diffuse reflection), the system efficiently captures both types of reflected light using a single light source, thus maintaining low device complexity while achieving high reading efficiency
Solution Approach 2:
The light source alternates between two fixed irradiation angles in a periodic manner. The light source is positioned at a first angle to read specularly reflected light, then rotated to a second angle to read diffusely reflected light. This periodic switching enables efficient capture of both reflection types without requiring multiple simultaneous light sources
2Measurement precision
If multiple irradiation angles are used to capture both specularly and diffusely reflected light, then the reading accuracy is improved, but the device complexity increases
Solution Approach 1:
The optical paths for capturing specularly and diffusely reflected light are merged into a single common optical path. Both types of reflected light are guided through the same optical components (beam splitter, objective lens, sensor) by rotating the light source to different angles, thus achieving high reading accuracy without increasing device complexity
Solution Approach 2:
A single optical path is designed to handle multiple functions: it can capture both specularly and diffusely reflected light by receiving light from different irradiation angles. The beam splitter, objective lens, and sensor all serve universally for both reading modes, eliminating the need for separate optical systems and reducing overall complexity
3Device complexity
If a common optical path is used for both specularly and diffusely reflected light, then the device complexity is reduced, but it becomes difficult to separate and process these reflections effectively
Solution Approach 1:
The light source is pre-positioned at specific angles before irradiation to ensure that specularly and diffusely reflected light enter the common optical path in distinct, predictable directions. This preliminary angular positioning facilitates easy separation and processing of the two light types despite using a common optical path
Solution Approach 2:
The beam splitter acts as an intermediary component in the common optical path that effectively separates and directs specularly and diffusely reflected light to appropriate processing paths. This intermediary element enables easy differentiation and handling of the two reflection types without requiring complex additional components
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
Enables efficient reading of both specularly and diffusely reflected light from a document using a single light source, simplifying the optical system and improving image quality by separating and processing these reflections effectively.
Implementation Method 1
specularly reflected light, which is obtained as light emitted by the irradiation unit is reflected from a first reflection surface so that a front surface of the object to be imaged in an irradiation region is irradiated with the reflected light, and the reflected light is specularly reflected from the front surface of the object to be imaged
Implementation Method 2
diffusely reflected light, which is obtained as the light emitted by the irradiation unit is reflected from a second reflection surface so that the front surface of the object to be imaged in an irradiation region is irradiated with the reflected light, and the reflected light is diffusely reflected from the front surface of the object to be imaged
Data Source
AI summary
A reading apparatus includes an light emitter that performs irradiation with light, a light receiver that receives light reflected from an object to be imaged, a first optical path in which specularly reflected light is guided to the light receiver as a read image, a second optical path in which diffusely reflected light is guided to the light receiver as a read image, and a switching section that switches between the first optical path and the second optical path by rotating the light emitter.