Inclined Prism Geometry to Deflect Reflected Light

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing cube beam splitters with incidence planes orthogonal to incident light can cause unwanted light interference or damage to optical components due to reflected light returning through the transmission path. Additionally, these devices often require larger optical devices due to misalignment of optical components.

Innovation Solution

The proposed prism design includes an incidence plane, a reflection plane, and an output plane, all extending in directions intersecting a common direction and differing from one another. This design deflects reflected light away from the transmission path, preventing interference and damage, while also allowing for a more compact optical device configuration by aligning optical components correctly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the incidence plane is made orthogonal to incident light, then the optical device structure is simple, but reflected light returns through the transmission path causing light interference or damage to optical components

Engineering Contradiction:

Improveincidence plane configurationVSAvoidlight interference and damage to optical components

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent applies asymmetry by making the incidence plane inclined rather than orthogonal to the incident light. This asymmetric configuration ensures that reflected light does not return through the transmission path, thereby preventing light interference and damage to optical components while maintaining structural simplicity

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent converts the potentially harmful reflected light into a beneficial configuration by inclining the incidence plane. The reflected light is redirected to a safe direction away from the transmission path, transforming what could be a harmful factor into a design feature that protects optical components

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Object-affected harmful factors

If the incidence plane is inclined to deflect reflected light, then light interference is prevented, but optical components are shifted in the rectilinear direction causing the device to increase in size

Engineering Contradiction:

Improvelight interference preventionVSAvoiddevice size in rectilinear direction

Core Design Contradiction:

Object-affected harmful factorsVSLength of stationary object

Solution Approach 1:

The patent resolves the size increase issue by carefully designing the inclination angle and positioning of the incidence plane such that optical components can be arranged in a compact configuration. The angular relationships are optimized to allow components to align properly in the rectilinear direction while still achieving light deflection, effectively using angular dimensions to solve a linear space problem

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Object-affected harmful factors

If the incidence plane is inclined, then reflected light is deflected from the transmission path, but optical components receiving light in inclined direction are not lined up properly causing positional shifts

Engineering Contradiction:

Improvereflected light deflectionVSAvoidoptical component alignment

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by optimizing the inclination angle of the incidence plane and the angular relationships between planes (θ and x angles). By carefully selecting these parameters, the patent achieves both light deflection and proper alignment of optical components, ensuring that components receiving light in the inclined direction can be correctly positioned and lined up

Inventive Principle:

Principle #35Parameter changes

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 new prism design effectively prevents light interference and damage to optical components by deflecting reflected light, and enables the downsizing of optical devices by ensuring proper alignment of optical components.

Implementation Method 1

a reflection plane that is a plane extending in the first direction and is where at least part of the light that has been input to the incidence plane is reflected

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 2

the prism changes a direction of travel of light approximately along a virtual plane orthogonal to the first direction and has a refractive index of n where n>1

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS20250180790A1Prism and optical device

Publication Date: 2025.06.05 FURUKAWA ELECTRIC CO LTD

AI summary

A prism includes an incidence plane, a reflection plane and an output plane, and changes a direction of travel of light and has a refractive index of n where n>1. In a case where the prism is viewed in a first direction, an angular difference between the incidence plane and the output plane is 90 degrees, the light input to the incidence plane travels in a second direction, the incidence plane extends to be directed more in the second direction from a position where the light is input, toward the output plane, and the following Expression 1 is satisfied when an angular difference between a virtual plane orthogonal to the second direction and the incidence plane is θ where θ>0 degrees and an angular difference between the output plane and the reflection plane is x degrees.45<x<45+2θ/n (1)