Compact Light Source Unit Using Dichroic Mirrors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light source units for projectors are bulky due to the size of the optical wheel and rotation components, which increases the overall size and power consumption of the projector.
Innovation Solution
A light source unit configuration using a first and second dichroic mirror to separate and manage light in different wavelength ranges, allowing for a compact design by eliminating the need for a rotating optical wheel and optimizing the layout of light sources and mirrors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an optical wheel with luminescent material layers and rotation processor is used to emit different color lights, then the light source unit can achieve multi-wavelength light emission, but the size of the light source unit increases due to the substrate and rotation components
Solution Approach 1:
The patent replaces the mechanical optical wheel system with a fixed mirror system. Instead of rotating luminescent layers, the invention uses multiple fixed dichroic mirrors (first and second dichroic mirrors) to direct light from separate blue and red light sources through stationary optical paths to the DMD, eliminating motors, rotating substrates, and complex mechanical assemblies while achieving the same multi-wavelength light emission function
Solution Approach 2:
The patent segments the optical system into separate functional modules: a blue light source module, a red light source module, a first dichroic mirror for wavelength separation, and a second dichroic mirror for path combination. This segmentation allows each component to be optimized independently and arranged in a compact fixed configuration, replacing the integrated but bulky rotating optical wheel
2Ease of operation
If an optical wheel with rotation processor is used for light modulation, then the light source unit can control different color lights, but the power consumption increases due to the rotation mechanism
Solution Approach 1:
The patent eliminates the power-consuming rotation processor and motor by replacing the mechanical rotating system with a stationary optical system using dichroic mirrors. The light color control is achieved through electronic control of the blue and red light sources and fixed optical path routing, completely removing the mechanical energy consumption associated with rotating the optical wheel while maintaining full color control capability
3Volume of moving object
If a compact light source unit design is implemented without optical wheel, then the size and power consumption are reduced, but the incident angles of light must be precisely managed through specific mirror configurations
Solution Approach 1:
The patent uses dichroic mirrors with specific wavelength-dependent optical properties to manage light paths. The first dichroic mirror is designed to reflect blue light at a first incident angle while transmitting red light at a second incident angle. This parameter-based approach (using wavelength-selective reflection and transmission angles) allows precise control of light paths without mechanical adjustment mechanisms, achieving compact design with fixed angular precision
Solution Approach 2:
The patent introduces dichroic mirrors as intermediary optical elements that mediate between the light sources and the DMD. These mirrors act as fixed intermediaries that automatically route different wavelengths at specific angles without requiring active control or adjustment, simplifying the system while maintaining precise angular management through the inherent optical properties of the mirror coatings
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 reduces the size and power consumption of the light source unit, enabling a more compact projector design while maintaining efficient light management and image projection capabilities.
Implementation Method 1
a first dichroic mirror configured to reflect the light in the first wavelength range incident thereon at a first incident angle and transmit the light in the second wavelength range incident thereon at a second incident angle
Implementation Method 2
transmit the light in the second wavelength range incident thereon at a second incident angle, which is different from the first incident angle
Implementation Method 3
a second dichroic mirror configured to reflect the light in the second wavelength range that has passed through the first dichroic mirror
Implementation Method 4
after having been reflected by the second dichroic mirror, the light in the second wavelength range is incident on the first dichroic mirror at the first incident angle to then be reflected by the first dichroic mirror
Data Source
AI summary
A light source unit includes a first light source configured to emit light in a first wavelength range, a second light source configured to emit light in a first wavelength range, a first dichroic mirror configured to reflect the light in the second wavelength range incident thereon at a first incident angle and transmit the light in the second wavelength range incident thereon at a second incident angle, which is different from the first incident angle, and a second dichroic mirror configured to reflect the light in the second wavelength range that has passed through the first dichroic mirror, wherein after having been reflected by the second dichroic mirror, the light in the second wavelength range is incident on the first dichroic mirror at the first incident angle to then be reflected by the first dichroic mirror.