Qualcomm smartwatch has MEMS-based interferometrically modulated reflective color display
San Diego, CA--Qualcomm, which has been developing an interferometric microelectromechanical systems (MEMS)-based reflective color display called Mirasol (originally created by Iridigm Display Corporation, which Qualcomm acquired in 2004), has now introduced a "smartwatch" containing the display; the touchscreen watch pairs via Bluetooth to Android phones (but not iPhones, unfortunately).
The 1.55 in. Mirasol display itself has a 288 × 192 pixel resolution, is visible in bright sunlight, and has a front/edge-illuminated screen for use in dim light (a similar approach to that of Amazon's E-ink-based Kindle). Although the resolution is low (and the display technology has been around for quite awhile), the device is an attempt to desmonstrate the display technology to a wider audience, with improvements in resolution likely coming in future devices.
How it works
Each pixel of the display consists of a thin, reflective membrane that rests a very small distance away from the glass—small enough for white-light interference effects to occur similar to those seen on oil films on water (the gap could be a single wavelength or small multiple of wavelengths). Because the film is conductive, the gap forming the resulting resonant cavity can be changed by applying a voltage, drawing the membrane toward the glass and shifting the resonance to the UV, therefore producing black. Lowering the voltage results in an interference-produced color.
With ideal coatings on the film and glass, the reflection at a single color can be very high. Practically, this means bright colors when seen in sunlight or room light, as well as low power consumption.
Qualcomm says the watch can operate for multiple days between charges.
For more info, see: http://www.qualcomm.com/mirasol
John Wallace | Senior Technical Editor (1998-2022)
John Wallace was with Laser Focus World for nearly 25 years, retiring in late June 2022. He obtained a bachelor's degree in mechanical engineering and physics at Rutgers University and a master's in optical engineering at the University of Rochester. Before becoming an editor, John worked as an engineer at RCA, Exxon, Eastman Kodak, and GCA Corporation.