| Summary: | 碩士 === 國立中興大學 === 精密工程學系所 === 105 === The headlamp design utilizes light sources with high collimation, and with uniform distribution of light energy to illumate the digital micromirror device (DMD). The DMD designed by Texas Inc. has high resolution of 2500 by 1600 array, 0.9-inch micromirror array diagonal and ± 12 degrees micromirror tile angle relative to flat state. In order to establish a freeform surface that can capture incident rays being reflected by the DMD, we first assume the light that hits the DMD to be as uniform and collimated as a white light laser. Since rays are parallel to each other, vectors of incident rays of the DMD are the same, and so are the reflected rays, which are also the incident rays of the freeform surface. We then mesh the DMD and the target plane to be illuminated 25 m away, according to the ECE R112 regulation, and assign positions to desired points. Every single point on the DMD has a corresponding point on the target plane, which help us determine the vector of each reflected ray of the freeform surface. We use MATLAB to calculate the propogation vector for each ray and obtain the positions of points on the freeform surface. Our optical models are of secondary optics, which means the optical design is an anti-glare design. However, the white light laser is at developing phase, so we use the light emitting diodes (LEDs) as light sources. We introduce optical components, such as collimated lens, reflective surface with high collimation and uniformity and Fresnel lens, to evenly distribut the energy of LED light onto the DMD. Moreover, in an anticipation to see a character to be projected onto the target plane, we aim to change paremeters of models so that the character will be as clear as what a white laser can produce.
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