Technologies interplay to create more life-like projection images at half the cost and power consumption
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Dr. Boris Stoeber (left) works with PhD student Reynald
Hoskinson (right) to design a micromirror array to address
the engineering problem of how to maximize light
distribution.
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The image quality of movies you enjoy at the cinema or on your home theatre system could one day be improved at a comparatively low
cost, thanks to micro-electro-mechanical system (MEMS) devices designed
at the University of British Columbia. Researchers from multiple
engineering disciplines—electrical, computer and mechanical—are
developing a high dynamic range light projector, incorporating an array
of steerable micromirrors that can be added to existing LCD- or
DLP®-based projection systems. The technology improves the brightness
and contrast ratio of the projected image by at least a factor of two,
resulting in a more intense and life-like image.
Dr.
Boris Stoeber, Assistant Professor with joint appointments in the
Departments of Mechanical Engineering, and Electrical and Computer
Engineering, explains: “There is no other comparable technology
available today that would improve the peak brightness of projected
images without changing the projector lamp. This is significant to the
consumer for two reasons: the cost of the lamp is 50% that of the
entire projector and higher peak brightness can be achieved without
moving to a lamp that consumes more power.” Another technical advantage
is provided by their micromirrors, tilting over a continuous range,
that redirect the light from the projector lamp with a finer degree of
control than digital micromirror devices, which allow only on/off
control.
Reynald Hoskinson, PhD student in the Department of
Electrical and Computer Engineering, is working with Dr. Stoeber to
design the micromirror array. He explains that their design addresses
the engineering problem of how to maximize light distribution. The
problem occurs because dark parts of a projected image are made by
blocking light—discarded light that can be better used to make bright
parts of the image brighter. The micromirror array modulates and
redirects light from the projector lamp before it reaches the
high-resolution image-forming element used in current projectors. By
channeling more of the light where it is needed, the result is higher
peak brightness, reduced power consumption by at least 50 per cent, or
a combination of the two.
What strikes Dr. Stoeber most about their technology is the interplay
of field-programmable gate array (FPGA) technology, image processing
and MEMS mirrors that manipulates the direction of individual light
bundles from a projector lamp to visibly improve the quality of
projected images, all while being more energy-efficient. Through CMC
Microsystems, the researchers accessed the Micragem MEMS prototyping
technology, provided in partnership with Micralyne Inc. in Alberta, to
create 25 separately controllable groups of micromirrors on a single
device. The first prototype has been integrated into a projector, along
with optical lenses, a light source and the image-forming element. FPGA
technology is used to drive the mirrors and (in the future) for image
processing.
Next steps for the research group include applying what they learned
from the initial prototype to iterate the design and make an improved
set of mirrors, moving towards a commercially-viable technology. Dr.
Stoeber explains: “We are in contact with a local company that
fabricates high-end video projectors. They are interested in
integrating our technology as a sub-component into their
next-generation, high-performance projector.” Watch for it at your
local cinema.