Image Scanning Unit Folded Light Path Stray Light Shielding
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Solution Overview
Problem
The existing image scanning units face challenges in reducing size and thickness due to the need for a large arrangement space for reflecting members, which hinders the miniaturization of scanners and copiers.
Innovation Solution
The image scanning unit is designed with a light source unit and reflecting members arranged in a way that divides the space into two sections, using a light-shielding member to prevent stray light from entering the reflecting members, allowing for efficient use of space and reducing the overall thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If a large arrangement space is ensured for reflecting members to form a continuous light path, then the light path length is sufficient for proper light guidance, but the overall thickness and size of the image scanning unit increases
Solution Approach 1:
The patent transitions from a conventional planar arrangement of reflecting members to a three-dimensional folded light path configuration. The light path is folded multiple times within the carriage frame, utilizing vertical and lateral dimensions to achieve sufficient optical path length without increasing the horizontal footprint or overall thickness of the scanner unit.
Solution Approach 2:
The patent employs a nested arrangement where intermediate reflecting members are positioned within the space defined by the carriage frame structure. The light path is folded back on itself, with reflecting members arranged in a compact, nested sequence that maximizes space utilization. This allows multiple reflection events to occur within a confined volume, achieving the required light path length without proportionally increasing the device dimensions.
2Length of moving object
If reflecting members are arranged in a compact space to reduce overall size, then the device thickness is reduced, but stray light may enter reflecting members and cause reading errors
Solution Approach 1:
The patent applies light-shielding treatments selectively to specific regions where stray light may contaminate the optical path. Rather than shielding the entire carriage frame, light-shielding members are positioned only at locations where stray light from the light source unit could reach the reflecting members or image reading section. This localized approach maintains compact dimensions while protecting against reading errors caused by stray light interference.
3Reliability
If additional light-shielding members are added to prevent stray light interference, then reading accuracy is improved, but the device complexity and number of components increases
Solution Approach 1:
The patent integrates light-shielding functions into existing structural components of the carriage frame rather than adding separate, standalone light-shielding members. The light-shielding members are merged with the frame structure, serving both structural support and optical shielding functions simultaneously. This reduces the total component count and simplifies assembly while maintaining the necessary stray light protection for accurate reading.
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 design enables a compact image scanning unit that can be integrated into downsized scanners or copiers without compromising reading accuracy, while also eliminating the need for additional light-shielding components, thus simplifying the structure.
Implementation Method 1
a light guide which is formed into a rod-like shape extending in a main scan direction and has, at at least one end thereof, an end face for taking in light
Implementation Method 2
a diffuse reflecting surface for diffusely reflecting the light taken in from the end face
Implementation Method 3
a plurality of reflecting members forming a reading light path guiding the reflected from the irradiation surface to an image reading section
Data Source
AI summary
Provided is an image scanning unit which makes it possible to improve scanning accuracy while also making the overall body thinner by appropriately positioning a plurality of reflection members within an effective space in a carriage frame without wasting space. An image scanning unit, wherein a frame is divided into at least two spaces facing an irradiation surface, a first accommodation unit for accommodating a light source unit is formed in one of the spaces, a second accommodation unit for accommodating at least one reflection member is formed in the other adjacent space, a first reflection member for initially receiving light reflected from the irradiation surface is positioned at the side opposite the irradiation surface with the first accommodation unit positioned therebetween, and a light-shielding member is provided between the first reflection member and the reflection member positioned in the other space and prevents light that has strayed from a scanning light path from the first reflection member from being incident on the reflection member in the other space.