Laser Diode Based Tiny Projector

The creation of smallest possible character projector is the basic concept of the Tiny Projector, where the character can be either linked dynamically with wireless RF connections or be integrated into mobile device.

The design of the circuit includes laser diodes that were salvaged from cheap key chain laser pointers and a micro motor having a single swiveling servo arm that makes a continuous full 360 degree rotation. This servo arm also drives the deflection mirror that results in a 38 degree left-right sweep. Doing this will lead to an unusually high overall laser projection angle of 104 degrees.

Cheap laser diodes were used to project a single line of text onto nearby walls, tables, and other surfaces for this small portable character projector. For mobile communication devices, one of the major user interface design challenges is that the devices should be as small as possible but will still provide a display as big as possible.

In using the laser diodes, the device projects the messages by adding a turning mirror in front of the laser beams. A transistor and a separate 3V power source are used to power the laser pointers’ operation.

Rest of the project