Speckle reduction for laser projection displays

摘要

Various embodiments of the present invention relate to a laser driver, and more particularly, to systems, devices and methods of applying low current pulses to a laser modulation current to reduce the speckling noise on the projected images.

主权项

1. A laser driver that drives a laser diode with a pulsed modulation current, comprising:
a controller that is coupled to receive and process video data; a pulse-off control module, coupled to the controller, the pulse-off control module controls at least a first analog switch and a second analog switch; a first current source, coupled in series with the first analog switch that is regularly switched off within one integration period of human eyes, the first current source generating a modulation current that is greater than a laser threshold current, such that the modulation current causes the laser diode to emit light; and a second current source coupled in series with the second analog switch, the second current source receives light-off pulses from the pulse-off control module that are shorter than one integration period of human eyes to generate a pulsed biasing current that causes the laser diode to emit no light during the light-off pulses when the second analog switch is closed thereby generating a plurality of laser waves that are incoherent to each other.