Image Scanner Edge Detection Using Transmissive Light
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Solution Overview
Problem
Existing image reading apparatuses face challenges in accurately detecting the size of originals with mixed sizes due to false operations from black parts and require dedicated image sensors, leading to increased size and cost.
Innovation Solution
The apparatus employs a dual-light-source system with a movable reference member and optical opening to enhance detection accuracy by using transmissive images and eliminating the need for a dedicated image sensor, allowing for downsizing and cost reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a dedicated image sensor is arranged to detect the edge of an original, then the detection accuracy of the original size is improved, but the size and cost of the image reading apparatus increase
Solution Approach 1:
The patent applies multi-functionality by enabling the existing image sensor to perform both its primary function of reading original images and a secondary function of detecting original edges through transmissive light detection. The control unit processes the image sensor output to extract edge detection information, eliminating the need for a dedicated edge detection sensor and reducing apparatus complexity while maintaining detection accuracy
Solution Approach 2:
The patent combines the edge detection function with the existing image reading system by using the same image sensor for both image capture and edge detection. The transmissive light detection is merged into the existing optical path, and the control unit integrates edge detection processing with image reading operations, thereby reducing device complexity without sacrificing measurement precision
2Device complexity
If shadow information from illumination is used to detect original size, then the detection method is simple, but false operations occur when black parts are present in the outermost area of the original
Solution Approach 1:
The patent introduces transmissive light as an intermediary detection method. Instead of relying on shadow information that can be contaminated by black parts, the system uses light transmission through the original to detect edges. The control unit analyzes the transmissive light intensity to identify original boundaries, providing reliable detection even when black parts are present in the outermost areas
Solution Approach 2:
The patent changes the detection parameter from shadow intensity to transmissive light intensity. By measuring how much light passes through the original rather than how much shadow is cast, the system achieves more reliable edge detection. The control unit processes transmissive light data to determine original boundaries, eliminating false operations caused by black parts that would appear as shadows
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 increases detection accuracy of the original's edge and reduces the size and cost of the image reading apparatus by utilizing the dual-light-source system to detect the outline of the original without a dedicated sensor.
Implementation Method 1
having a first light source for emitting light to one surface of the original, and adapted to receive the light emitted from the first light source and subsequently reflected at the one surface of the original
Implementation Method 2
having a second light source for emitting light to be received by the first reading unit, and having an optical opening for causing the light emitted from the second light source and subsequently received by the first reading unit to pass therethrough
Data Source
AI summary
An image reading apparatus capable of increasing the detection accuracy of the size of an original and eliminating the need for an image sensor dedicated to detection of the size of an original. A first reading unit has a first light source disposed on one side of a conveyance path of an original for emitting light to one surface of the original. A second reading unit has a second light source disposed on the other side of the conveyance path for emitting light to be received by the first reading unit, an optical opening for causing the light emitted from the second light source and subsequently received by the first reading unit to pass therethrough toward the first reading unit. The original is detected on the basis of the resultant output of the first reading unit upon receipt of the light emitted from the second light source.