Rod-like Light Guide with Paraboloid Reflective Surface
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Solution Overview
Problem
Existing image reading devices face inefficiencies in illumination due to diverging light from flat reflective surfaces, concave reflectors, and prismatic emission surfaces, which degrade illumination depth and efficiency.
Innovation Solution
An illumination device featuring a rod-like light guide with a paraboloid reflective surface and a light-scattering portion at its focus, scattering incident light to maintain collimated illumination across a great depth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a flat reflective surface is used in the light guide, then the structure is simple, but light diverges and illumination efficiency decreases
Solution Approach 1:
The patent applies a paraboloid curved reflective surface instead of a flat surface. This curvature is specifically designed to reflect light from the light source at one end of the rod-like light guide and make the light travel substantially parallel to the longitudinal axis, preventing divergence and maintaining illumination efficiency throughout the length of the light guide.
2Illumination intensity
If a concave reflector with elliptic curve is used, then light can be collected, but light diverges from the emission surface and depth of illumination is insufficient
Solution Approach 1:
The patent uses a paraboloid curved reflective surface with specific geometric properties that differ from elliptic curves. The paraboloid shape ensures that light reflected from the surface travels parallel to the longitudinal axis of the light guide, maintaining collimated light over long distances and achieving great depth of illumination without divergence.
3Illumination intensity
If a prismatic emission surface is used in cylindrical parabolic block, then light can be emitted, but light is reflected diffusely and illumination efficiency degrades
Solution Approach 1:
The patent applies a light-scattering portion specifically at the emission surface of the rod-like light guide. This localized treatment scatters light in the longitudinal direction to expand the illumination area while maintaining overall directionality and preventing diffuse reflection that would degrade illumination efficiency. The rest of the light guide maintains its optical properties for efficient light transmission.
4Illumination intensity
If light is emitted directly from light source array, then illumination is provided, but depth of illumination is insufficient and brightness uniformity is poor
Solution Approach 1:
The patent introduces a rod-like light guide as an intermediary between the light source and the manuscript to be illuminated. The light guide receives light from the light source at one end and transmits it along its longitudinal axis to the emission surface at the other end, where light is emitted with great depth and improved brightness uniformity across the illumination area.
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
The solution ensures efficient and stable illumination with a great depth of illumination, maintaining brightness and color tone uniformity even with aged light sources, and preventing light leakage.
Implementation Method 1
a reflective surface with a paraboloid shape to reflect, toward the emission surface, light from a focus of the paraboloid shape or light traveling from a predetermined area and passing through the focus
Implementation Method 2
a light-scattering portion, having a predetermined scattering area, to scatter incident light through the incident surface and reflect the light toward the reflective surface
Implementation Method 3
a rod-like light guide extending in a longitudinal direction to guide incident light toward an object to be illuminated
Data Source
AI summary
An illumination device includes a light source and a rod-like light guide extending in a longitudinal direction for guiding incident light to an object to be illuminated. The light source is disposed at an end of the light guide extending in a longitudinal direction. The light guide includes an incident surface at the longitudinal end to receive light emitted from the light source, a flat emission surface to emit light incident on the light guide toward the object to be illuminated, a parabolic reflective surface to reflect, toward the emission surface, light from a focus of the paraboloid shape of the refractive surface or light passing through the focus from a predetermined area, and a light-scattering portion, having a predetermined area, to scatter light entering through the incident surface and reflect the light toward the reflective surface. The light-scattering portion is placed at the focus of the paraboloid shape or at a position where light reflected by the scattering area on the light-scattering portion passes through the focus.