Variable Dichroic Mirror for Projection Lighting Spectral Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing projection-type image display apparatuses face challenges in improving the spectral characteristic of blue light without significant changes to their configuration, as current methods either reduce luminance or require complex modifications.
Innovation Solution
A lighting apparatus with a dichroic mirror or polarization beam splitter that can selectively transmit and reflect blue light, allowing for variable spectral modification by adjusting the dichroic mirror's position or the polarization of the light, enabling combination with generated green light to achieve improved spectral characteristics without altering the existing setup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a blue laser diode and phosphor are used to generate green light, then the spectral characteristic of green light is improved, but the blue light component is reduced and the configuration becomes complex
Solution Approach 1:
The patent employs a movable dichroic mirror that can be positioned in different locations within the optical path. When the mirror is in the first position, it reflects blue light to the phosphor for green light generation. When moved to the second position, it allows blue light to pass through directly. This dynamic repositioning enables selective spectral modification without permanent structural changes to the projection apparatus.
Solution Approach 2:
The dichroic mirror serves as an intermediary element that mediates between the blue light source and the phosphor material. It selectively reflects specific wavelengths to the phosphor while transmitting others, enabling controlled green light generation without directly modifying the core projection system architecture.
2Illumination intensity
If the dichroic mirror is moved closer to the light source, then the spectral characteristic improvement is enhanced, but the available space for movement is reduced
Solution Approach 1:
The patent resolves the space constraint by moving the dichroic mirror along the optical axis (depth dimension) rather than laterally. The mirror can be positioned in different axial locations within the optical path, allowing spectral modification effectiveness to be adjusted without requiring lateral space that would conflict with other optical components.
3Power
If the blue light intensity is increased to improve luminance, then the luminance requirement is met, but the spectral characteristic of blue light deteriorates
Solution Approach 1:
The patent changes the spectral parameters of blue light by using a dichroic mirror with specific reflectance characteristics. The mirror reflects a portion of the blue light spectrum while transmitting others, effectively modifying the spectral distribution without changing the overall luminance output. This allows simultaneous optimization of both luminance and spectral characteristics.
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
This solution allows for selective improvement of blue light spectral characteristics with a simple configuration, maintaining or enhancing luminance and stability, while reducing the need for significant changes to existing devices, thus providing a cost-effective and efficient method for achieving desired color balance.
Implementation Method 1
a separation element partially transmitting the first color component light, partially reflecting the first color component light
Implementation Method 2
A lighting apparatus with a dichroic mirror or polarization beam splitter that can selectively transmit and reflect blue light
Implementation Method 3
an illuminant excited by the first color component light transmitted through the separation element to generate the second color component light
Implementation Method 4
an optical system combining the first color component light made incident on the separation element from the light source and reflected by the separation element with the second color component light made incident on the separation element from the illuminant
Data Source
AI summary
A lighting apparatus includes: a light source generating a first color component light; a separation element partially transmitting the first color component light, partially reflecting the first color component light, and transmitting a second color component light different from the first color component light at a certain moment; an illuminant excited by the first color component light transmitted through the separation element to generate the second color component light; and an optical system combining the first color component light made incident on the separation element from the light source and reflected by the separation element with the second color component light made incident on the separation element from the illuminant and transmitted through the separation element. The separation element is configured to have variable transmittance and reflectance with respect to the first color component light.