Light Guide with Diffusing Section for Illuminating Device
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Solution Overview
Problem
Conventional illuminating devices suffer from low light usage efficiency due to light scattering and leakage at the junction of inclined surfaces in the light-splitting portion, leading to inefficient use of light emitted from the point light source.
Innovation Solution
A light guide with a light-splitting portion featuring symmetrical inclined surfaces and a light-diffusing section that directs light into first and second light guide portions, ensuring total reflection and minimizing light leakage by optimizing the angles and connections between these surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a light-splitting portion with two inclined surfaces is used to split light from a point light source, then light can be divided into two beams for illumination, but light scattering and leakage occur at the junction of the inclined surfaces, reducing light usage efficiency
Solution Approach 1:
A light guide portion is introduced as an intermediary component between the light source and the two light guide portions. This light guide portion receives light from the point light source and guides it to the light-splitting portion, preventing direct illumination of the junction area and reducing light leakage. The intermediary structure allows effective light splitting while minimizing energy loss at the junction.
Solution Approach 2:
The patent applies different structural characteristics to different regions: the light-splitting portion has inclined surfaces for effective light division, while the junction area is designed with specific curvature and connection features to minimize scattering. The light guide portion has a specific shape that directs light away from the junction, creating local optimizations that collectively improve overall light efficiency.
2Ease of manufacture
If the junction of inclined surfaces is formed by molding or cutting, then manufacturing is simplified, but the junction becomes a curved surface that scatters and transmits light, causing light leakage
Solution Approach 1:
The patent specifies precise geometric parameters for the light guide portion, including its shape, size, and position relative to the light-splitting portion. By controlling these parameters, the design accommodates the curved junction surface created by molding or cutting while directing light away from this imperfection, thus maintaining manufacturing simplicity without sacrificing optical performance.
3Productivity
If light enters the junction of inclined surfaces, then light can pass through or scatter, but this causes light to leak from the illuminating device without entering the light guides
Solution Approach 1:
The light guide portion acts as a mediator that intercepts light before it reaches the problematic junction area. It guides light through a controlled path that bypasses the junction, ensuring that light is transmitted effectively to the light-splitting portion without leaking through the junction of the inclined surfaces.
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 significantly reduces light leakage and enhances the effective use of light from the point source, producing two linear light beams with consistent intensity, thereby improving the illuminating device's efficiency and image quality in image reading applications.
Implementation Method 1
a first light guide portion and a second light guide portion configured to guide the first light and the second light, respectively, in a specified direction while total-reflecting the first light and the second light, respectively
Implementation Method 2
the light-diffusing section is configured to diffuse the light emitted from the point light source toward the first light guide portion and the second light guide portion
Implementation Method 3
the first reflective portion and the second reflective portion configured to reflect the first light propagating in the first light guide portion and the second light propagating in the second light guide portion, respectively
Data Source
AI summary
A light guide having; an entrance portion; a light-splitting portion; a first and a second light guide portion; and a first and a second reflective portion provided in or on the first and second light guide portions, respectively. The first and second light guide portions emit light reflected by the first reflective portion and light reflected by the second reflective portion to outside as a first linear light beam and a second linear light beam, respectively. The light-splitting portion projects toward the entrance portion, and has a first inclined surface, a second inclined surface and a connecting section. The entrance portion has a light-diffusing section opposed to the connecting section in a direction of optical axis, and the light-diffusing section diffuses the light emitted from the point light source toward the first light guide portion and the second light guide portion.