Most existing head-up displays generate images using LCDs. Light-emitting diodes produce light and liquid crystal arrays act as shutters, controlling whether or not light reaches each pixel. This approach drains power, and the images often aren’t bright enough to be visible in daylight. Newer displays use either liquid crystal devices or hundreds of tiny mirrors to reflect light onto each pixel. While more energy efficient, these displays are still not very bright.
Microvision’s system uses a set of three lasers—red, green and blue—and a single, millimeter-wide silicon mirror that tilts on two axes. The lasers put out light at different intensities, and the three colors are mixed to produce the final pixel color. As the lasers shine light on the mirror, it rapidly scans horizontally and vertically, painting the image onto the windshield one pixel at a time. This happens so fast that the image looks static. Evans says that the lasers’ pure, saturated colors result in more vivid images with a higher contrast ratio, so they are visible in daylight. Illuminating one pixel at a time also saves energy. And the use of a single mirror rather than an array makes the device smaller, simpler, and cheaper.
Why is it I always think of this when someone mentions lasers?
