Diffractive Display Optics With Dichroic Filtering Against Solar Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display systems in vehicles are sensitive to external light, particularly solar radiation, which can cause interference, reflections, and heating issues that may lead to irreversible damage to the light source.
Innovation Solution
A display device comprising a light source, a diffractive optical element, and a dichroic filter, where the dichroic filter is placed in the path of the light beam to selectively transmit only a portion of the external radiation corresponding to its bandwidth, reducing external light interference and heat buildup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a light source is used to illuminate a diffraction device in a display system, then the character or symbol becomes visible on the transparent surface, but the system becomes sensitive to external light causing interference, reflections, and overheating
Solution Approach 1:
A dichroic filter is introduced as an intermediary component between the external environment and the display system. This filter selectively transmits wavelengths corresponding to the light source while blocking other wavelengths, thereby mediating the interaction between external light and the display components to prevent interference and overheating
Solution Approach 2:
The system utilizes wavelength-selective filtering by changing the spectral parameters of transmitted light. The dichroic filter is designed with specific bandwidth characteristics that match the light source wavelength range, allowing only desired wavelengths to pass through while blocking harmful external radiation
2Object-affected harmful factors
If a dichroic filter is added to block external radiation, then external light interference and overheating are reduced, but the device complexity increases
Solution Approach 1:
The dichroic filter serves multiple functions simultaneously: it blocks harmful external radiation, transmits the light source wavelengths, and protects the display components. This multi-functionality justifies the addition of the component by providing several benefits from a single element
Solution Approach 2:
The patent specifies that the dichroic filter's bandwidth should cover at least part of the light source wavelength range, optimizing the balance between blocking external radiation and transmitting useful light. This parameter optimization reduces the need for additional components
3Adaptability or versatility
If multiple diffractive optical elements are used to create different colored symbols, then color versatility is improved, but the device complexity and space requirements increase
Solution Approach 1:
The system segments the light spectrum using multiple dichroic filters, each with different bandwidth characteristics. This segmentation allows different wavelength ranges to be selectively transmitted, creating different colored symbols from a single light source without requiring multiple physical light sources
Solution Approach 2:
A single light source is made multi-functional by using it with multiple dichroic filters that can be selectively positioned or activated. This allows the same light source to produce different colored symbols, eliminating the need for multiple separate light sources and reducing overall device complexity
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 effectively reduces the risks of heat-related damage and parasitic lights, while allowing the display of symbols or characters with improved aesthetic appeal by filtering out unwanted external radiation.
Implementation Method 1
a dichroic filter placed in the path of said image light beam and whose bandwidth covers at least part of said wavelength range so as to transmit at least part of said image light beam
Implementation Method 2
a diffractive optical element whose operating range is adapted to said wavelength range and arranged to receive said source light beam and transmit an image light beam
Data Source
Figure 1~3
Figure 4~5
AI summary
The invention relates to a display unit (1) comprising: - a light source (20) designed to generate a source light beam (S) extending over a predetermined wavelength range; - a diffractive optical element (40) the operating range of which is adapted to the wavelength range and arranged to receive the source light beam (S) and transmit an image light beam (I); and - a dichroic filter (50) which is positioned in the path of the image light beam and the bandwidth of which covers at least part of the wavelength range so as to transmit at least part of the image light beam.