Picoprojectors: Researchers Create Tiny More Efficient Projectors
Posted on July 16, 2012
Researchers from North Carolina State University and ImagineOptix Corporation have developed new technology to convert unpolarized light into polarized light. The researchers say this makes projectors that use liquid crystal (LC) technology almost twice as energy efficient. The new technology has resulted in smaller, lower cost and more efficient projectors, meaning longer battery life and significantly lower levels of heat. The researchers created the tiny quarter-sized picoprojector (pictured above), which could be embedded in a smartphone, tablet or other device.
The most common method of polarizing light involves passing the unpolarized light through a polarizing filter. This process wastes more than 50 percent of the originally generated light, with the bulk of the "lost" light being converted into heat - which is why projectors get hot and have noisy cooling fans. The technology developed at NC State allows approximately 90% of the unpolarized light to be polarized and, therefore, used by the projector.
Dr. Michael Escuti, co-author of a paper describing the research and an associate professor of electrical and computer engineering at NC State, says, "This technology, which we call a polarization grating-polarization conversion system (PGPCS), will significantly improve the energy efficiency of LC projectors. The commercial implications are broad reaching. Projectors that rely on batteries will be able to run for almost twice as long. And LC projectors of all kinds can be made twice as bright but use the same amount of power that they do now. However, we can't promise that this will make classes and meetings twice as exciting."
The new tech, called a polarization grating-polarization conversion system, is pictured below.
The paper, "Efficient and monolithic polarization conversion system based on a polarization grating," was published July 10 in Applied Optics.