Projection Light Engine Module with Dichroic Beam Splitting
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Solution Overview
Problem
High-luminance projection systems with digital micromirror devices face challenges in meeting market demands due to high production costs and limited luminance, particularly with the expensive digital micromirror device technology.
Innovation Solution
A projection device with a light engine module that includes a first and second dichroic element, light valves, converging elements, guiding elements, and a light combining element, which divides and converts illumination beams into color beams, reducing opening angles and allowing for a smaller light combining element, thus minimizing module size and production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a single digital micromirror device is used for high-luminance projection, then the projection system can be simplified, but the luminance requirement cannot be met
Solution Approach 1:
The projection system is divided into two separate light paths, each with its own digital micromirror device. The first light path handles the first color beam and the second light path handles the second color beam. By segmenting the projection function across multiple devices working in parallel, the system achieves high luminance output that cannot be obtained from a single device, while each individual device operates at optimal performance levels.
Solution Approach 2:
The patent combines the output of two separate digital micromirror devices through a light combining element. The first image beam from the first light valve and the second image beam from the second light valve are merged into a single projection beam. This merging of multiple light sources allows the system to achieve the required high luminance while maintaining the simplicity of individual device operation.
2Illumination intensity
If expensive digital micromirror device technology is used, then high-luminance projection can be achieved, but production costs increase
Solution Approach 1:
The system segments the high-luminance requirement into two separate, less expensive digital micromirror devices operating in parallel. Rather than requiring one extremely expensive high-luminance device, the patent uses two standard-performance devices that together achieve the same total luminance output, thereby reducing individual device costs and overall system expense.
Solution Approach 2:
The patent creates a duplicate light path with a second digital micromirror device that mirrors the first light path's configuration. By copying the proven, cost-effective single-device architecture and operating two copies simultaneously, the system achieves high luminance through additive output while using standardized, readily available components rather than custom expensive devices.
3Object-affected harmful factors
If the light combining element is positioned far from the projection lens, then light interference can be minimized, but the module size increases
Solution Approach 1:
The patent positions the light combining element in a location that utilizes three-dimensional space efficiently near the projection lens. Rather than placing it far along the optical axis to avoid interference, the design uses spatial arrangement in multiple dimensions - positioning the light combining element at a specific off-axis location and using tilted dichroic elements to separate and combine light paths in a compact volumetric arrangement that minimizes interference while maintaining small module size.
Solution Approach 2:
The dichroic elements serve as intermediaries that manage light interference by selectively reflecting and transmitting different wavelength ranges. The first dichroic element separates the illumination beam into first and second color beams, directing them to different light valves. The second dichroic element acts as an intermediary to combine the returned beams, using wavelength-based filtering to prevent interference while enabling compact positioning of the light combining element near the projection lens.
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 achieves high luminance projection while reducing overall volume and manufacturing costs by shortening the back focal length and simplifying lens design, enabling the use of smaller lenses and minimizing light interference.
Implementation Method 1
The first dichroic element is disposed on a transmission path of the illumination beam and is used for dividing the illumination beam into a first color beam and a second color beam. The first wavelength range of the illumination beam passes through the first dichroic element to form the first color beam. The second wavelength range of the illumination beam is reflected by the first dichroic element to form the second color beam.
Implementation Method 2
The light combining element is disposed on transmission paths of the first image beam from the first light valve and the second image beam from the second light valve
Data Source
Figure 1
Figure 2~3
Figure 4A~4B
AI summary
A projection device and a light engine module thereof are provided. The light engine module includes a first dichroic element, a first light valve, a second light valve, a light combining element, a first light converging element, a second light converging element, a first light guiding element, and a second light guiding element. The first dichroic element divides an illumination beam into a first color beam and a second color beam. The first light valve converts the first color beam into a first image beam. The second light valve converts the second color beam into a second image beam. The light combining element is disposed on transmission paths of the first image beam and the second image beam. The first light guiding element guides the first color beam to the first light valve.