[imax500]

The invention is composed of two parts:

1. The first part is a modulated retro-reflector structure where current or charge is used to modulate say, a MEMS retro-reflector structure. These devices are known in the literature having being proposed solely for optical communications where they need to operate at very high frequencies. See, for example, http://en.wikipedia.org/wiki/Modulating_retro-reflector

2. The second part is a device that drives the modulating feature of the modulating retro-reflector. Typically this will be a MEMS structure that requires current or power modulated by a semiconductor device built into the structure or in a separate board. The power source can be either:

a. a low power long-life battery and a photodiode that is used to detect (1) nightime/dark conditions and (2) incoming incident light, such that the modulating feature is only used when necessary to conserve power, or,

b. more advantageously a built in photovoltaic solar cell that uses some of the incident light to drive the MEMS switching structure to enable modulation. This device can also include a rechargeable battery to store power during daylight periods.

This invention is made by a number of means:

1. The Modulating MEMS structure is made in a typical MEMS fab
2. The control electronics are made in various semico fabs and them fabricated into printed circuit boards - as per typical electronic devices
3. The whole lighting device is then packaged in a plastic housing, typically in Chine where this is done manually

The invention is used very simply where it replaces current static light reflectors.