Abstract
We proposed a design for a LASER pico-projector with a low speckle contrast value and high contrast ratio that maintains system efficiency. The method for speckle contrast reduction utilizes two diffusers and a Voice Coil Motor (VCM) oscillator. The two different diffusers for a high contrast ratio and high system efficiency can be divided into two categories. In Category 1, the speckle contrast value can be decreased to 2.80% by using a circular symmetric diffuser. At the same time, the full-on/full-off (FO:FO) contrast ratio can be maintained within 1200:1-1300:1, but the system efficiency decreases 1.50%. In Category 2, the speckle contrast value can be reduced to 6.50% by using an elliptically scattering diffuser. At the same time, the FO:FO contrast ratio can be maintained within 1300:1-1400:1, and the system efficiency decreases by only 1.00%.
Highlights
With the development of semiconductor manufacturing, solid-state light sources for display [1] have to be mass-produced
We design a light amplification by stimulated emission of radiation (LASER) pico-projector that has the advantages of lower speckle contrast value and higher FO:FO contrast ratio while still maintaining system efficiency
The main reason is that the light increases reflect time in the light pipe in the vertical vibrating direction than in the horizontal vibrating direction
Summary
With the development of semiconductor manufacturing, solid-state light sources for display [1] have to be mass-produced. For the pico-projectior, the etendue of the LED is still too large to reduce the size of the illumination system. The speckle phenomenon is an inevitable problem when a LASER is used as the source in a pico-projector This is the interference pattern caused by the scattering of light from the screen or the rough surface. Elimination of the speckle phenomenon, which reduces image quality, is an important issue in the LASER pico-projector design. The above methods can reduce the speckle contrast value to an invisible level, but the size or system weight are still too large for pico-projector applications. They cannot be adapted for use in the LASER pico-projector. The FO:FO contrast ratio can be maintained at 1182.36:1
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
