DMD Headlamp Illumination Control for Brightness and Mirror Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
DMD lighting systems face challenges in achieving sufficient brightness due to etendue limitations and efficiency constraints, and operating at high temperatures leads to hinge memory and stiction problems, limiting reliable operation.
Innovation Solution
Implementing multiple illumination sources positioned to reflect light from micro-mirrors at specific angles and controlling them synchronously with the micro-mirror positions, using a reduced duty cycle to avoid hinge memory and stiction while maintaining brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the DMD array is operated at 100% duty cycle to achieve maximum brightness, then the illumination intensity is improved, but hinge memory problems and stiction problems arise in the micro-mirror devices
Solution Approach 1:
The patent applies periodic action by operating the DMD array at a reduced duty cycle (e.g., 50%) rather than continuously at 100%, allowing the micro-mirrors to periodically return to a neutral position. This periodic resetting prevents hinge memory and stiction problems while maintaining acceptable brightness levels through synchronized illumination sources.
2Reliability
If the DMD array is operated at a reduced duty cycle to avoid hinge memory and stiction problems, then the reliability is improved, but the brightness at the output of the lamp system is substantially reduced
Solution Approach 1:
The patent merges multiple illumination sources (e.g., two or more LED sources) to compensate for the reduced duty cycle operation. By combining the light output from multiple sources, the system maintains sufficient brightness levels even when the DMD array is active only part of the time, thus resolving the contradiction between reliability and illumination intensity.
Solution Approach 2:
The patent employs dynamic control of multiple illumination sources, adjusting their intensity and timing to match the reduced duty cycle operation of the DMD array. This dynamic adjustment ensures that the total light output remains adequate for the application while allowing the micro-mirrors to operate reliably at lower duty cycles.
3Illumination intensity
If multiple illumination sources are used to compensate for reduced duty cycle operation, then the brightness is maintained, but the device complexity increases
Solution Approach 1:
The patent designs the multiple illumination sources to serve universal functions: each source can independently illuminate the DMD array, and their combined output provides the necessary brightness. This multi-functionality allows the system to maintain brightness while managing complexity through standardized, interchangeable light sources that can be controlled in various patterns.
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 system achieves increased brightness and reliability by overcoming hinge memory and stiction issues, allowing DMD devices to operate effectively in high-temperature environments.
Implementation Method 1
each illumination source positioned so light from the respective illumination source is reflected by the micro-mirrors of the DMD device when the micro-mirrors are in a corresponding one of the multiple positions
Data Source
Figure 1~4
Figure 2
Figure 5~7B
AI summary
In described examples, a DMD illumination system (50) having multiple illumination sources (60, 66). A DMD illumination system (50) includes a plurality of illumination sources (60, 66), each of the illumination sources (60, 66) directing light onto the digital micro-mirror device (52) corresponding to a respective position of an array of micro-mirrors (54), each illumination source (60, 66) being positioned to cause reflected light from the array of micro-mirrors (54) to be projected out of the system (50), and control circuity (64) coupled to the plurality of illumination sources (60, 66) and to the digital micro-mirror device configured for controlling the position of the array of micro-mirrors (64) and further configured for providing control signals (A, B) for turning each of the plurality of illumination sources (60, 66) on and off, so that the light from the plurality of illumination sources strikes the array of micro-mirrors (54) and the light is reflected from the digital micro-mirror device (52) and out of the system (50).