MEMS Projectors Showed Off at Trade Show

Aug 5, 2009 16:39 Tsuneyuki Miyake, Nikkei Microdevices

Some companies exhibited projectors equipped with MEMS scanners at Exhibition Micromachine/MEMS 2009, including Panasonic Electric Works Co Ltd's laser scanner and Taiwanese firm's ultra-small projector.

Panasonic Electric Works showed off a two-axis MEMS scanner to demonstrate its wafer-level packaging (WLP) technology. The company vacuum-sealed a MEMS mirror formed on a Si substrate with two glass substrates by using its WLP technology.

By putting the mirror in a vacuum atmosphere, the air resistance is reduced when the scanner is in operation, making it possible to increase the amplitude (deflection angle of the mirror). In addition, it enabled to move the mirror with a smaller driving force and, thus, to use an electrostatic actuator. In general, for the scanning of a MEMS mirror, an electromagnetic or piezoelectric actuator is used because of their high driving force.

This time, Panasonic Electric Works demonstrated "virtual switches." They are the logos that are projected on panels with laser lights and represent an electric fan, lighting equipment and speaker, respectively. The user can control the power supply of each device by touching them.

The ultra-small projector was exhibited by Technohands Co Ltd, a Japan-based manufacturer of small actuators such as motors for galvanometer mirrors. The company showcased OPUS Microsystems Corp's MEMS scanner and an ultra-small projector equipped with it and displayed color movies by using laser light sources for three primary colors.

For the red and blue lasers, direct oscillation types manufactured by a Taiwanese maker are used. As for the green laser light source, Technohands did not have any information. The luminance of the light sources is 10lm.

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