Vehicle Light Module With Beam-Folding Prism for Compact Illumination
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Solution Overview
Problem
Current lighting and signaling modules face challenges in achieving significant illumination while maintaining a compact design due to interference issues between the micromirror array and projection device, leading to increased cost and size, especially when using multiple LED light sources.
Innovation Solution
A light module incorporating a prism with controlled refractive indices and a glass interface between the prism and impact surface, allowing for total internal reflection and eliminating stray reflections, enabling closer placement of optical components without interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the magnification of the lens used for the input device is increased or it is brought closer to the micromirror array, then the illumination is improved, but it causes interference with the projection device
Solution Approach 1:
The patent introduces a beam folding prism that redirects the light path through a different spatial dimension. Instead of directly increasing lens magnification or proximity which causes interference, the prism folds the optical path to achieve the same illumination effect without component interference, effectively solving the contradiction by changing the spatial arrangement.
Solution Approach 2:
The beam folding prism acts as an intermediary element between the input lens and the micromirror array. It mediates the light path by redirecting beams through total internal reflection, allowing the system to achieve high illumination without direct interference between the lens and projection device, thus resolving the technical contradiction.
2Illumination intensity
If multiple LED light sources are used to increase luminous flux, then the illumination is improved, but the cost and size increase
Solution Approach 1:
The patent replaces the mechanical approach of using multiple LED light sources with an optical solution. Instead of adding more light sources to increase luminous flux, the system uses a beam folding prism to optimize the light path and improve illumination efficiency, thereby achieving higher luminous flux without increasing the number of LED sources, which reduces both cost and size.
Solution Approach 2:
The patent changes the optical parameters of the system by introducing the beam folding prism, which alters the light path geometry. This parameter change allows the system to achieve improved illumination and luminous flux distribution without adding more light sources, thus avoiding the increased cost and size that would result from using multiple LEDs.
3Volume of moving object
If the beam path is folded to improve compactness, then the size is reduced, but stray reflections increase
Solution Approach 1:
The patent converts the potential harm of stray reflections into a beneficial effect by using total internal reflection within the beam folding prism. The prism's optical design ensures that reflections that would otherwise be stray are systematically directed along the intended light path, transforming what could be a harmful effect into a useful mechanism for beam folding and redirection.
Solution Approach 2:
The patent changes the refractive index parameters and surface angles of the beam folding prism to optimize the light path. By carefully selecting these parameters, the system achieves compact beam folding while minimizing stray reflections through precise control of total internal reflection conditions, thus resolving the contradiction between compactness and reflection control.
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
Enhances luminous efficacy by allowing for increased illumination without increasing size, facilitating adjustment of optical components, and reducing unwanted reflections, thus improving beam control and flexibility.
Implementation Method 1
transmit between the first face and the third face at least a part of the light rays from the transmitted part to the impact surface
Implementation Method 2
form reflected rays by reflection of at least a part of the light rays returned by the impact surface, by total internal reflection on the first face
Implementation Method 3
the interface material, the glass material, and the prism material have the same refractive index, or refractive indices that do not differ from each other by more than 10%. Under these conditions, stray reflections due to Fresnel's laws are eliminated or greatly reduced
Data Source
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AI summary
The invention relates to a light module for a vehicle, comprising a light source (21), a pixelated digital imaging system, and an optical input device (22) inserted, along the path of the rays coming from the source (21), between the source (21) and the pixelated digital imaging system, in order to transmit a transmitted portion of the rays coming from the source (21) to the pixelated digital imaging system, the light module further comprising a prism (26) that includes first, second and third faces (26a, 26b, 26c) and is configured to: - transmit, between the first and third faces (26a, 26c), rays of the transmitted portion towards the impact surface (24); - form reflected rays by reflecting rays returned by the impact surface (24), by total internal reflection on the first face (26a); and - return reflected rays via the second face (26b). A solid interface having a selected optical index is disposed between a pane associated with the imaging system and a face of the prism.