Scanning MEMS mirror angle-doubling using polarization
AssigneeGoogle Inc.
InventorDaniel Adema
Life of this patent
Estimating the term…
Abstract
Systems and methods for manipulation of the polarization state of light emitted by a laser projector to reduce the angle range of a scanning mirror articulated by a micro-electromechanical system MEMS to reduce power consumption are disclosed. A system includes a light source configured to emit laser light, a scanning mirror, and an angle expander disposed between the light source and the scanning mirror, the angle expander being configured to cause the laser light from the light source to be reflected at least once from the angle expander and at least twice from the scanning mirror.
Claims19
An apparatus comprising:
- a light source configured to emit laser light;
- a scanning mirror;
- and
- an angle expander disposed between the light source and the scanning mirror, wherein the angle expander is configured to cause the laser light from the light source to be reflected at least once from the angle expander and at least twice from the scanning mirror.
A method comprising:
- emitting, from a laser light source, laser light having a first linear polarization towards an angle expander;
- transmitting the laser light having the first linear polarization through the angle expander disposed between the laser light source and a scanning mirror, the angle expander comprising a polarization beam splitter (PBS) and a quarter-wave plate (QWP), wherein the QWP is disposed between the PBS and scanning mirror;
- reflecting for a first time, at the scanning mirror, laser light transmitted from the angle expander;
- reflecting, at the PBS, the laser light reflected from the scanning mirror;
- reflecting for a second time from the scanning mirror, the laser light reflected from the PBS;
- and
- transmitting, through the PBS, the laser light reflected from the scanning mirror.
A laser projector system comprising:
- an optical engine configured to emit laser light along a path;
- a scanning mirror configured to reflect the laser light;
- a polarization beam splitter (PBS), disposed in the path of the laser light between the optical engine and the scanning mirror, the PBS being configured to selectively reflect laser light based on a polarization state of the laser light;
- and
- a quarter-wave plate (QWP), disposed in the path of the laser light between the scanning mirror and the PBS,
- wherein the PBS is positioned at a non-zero angle relative to a rotational axis of the scanning mirror.
Dependencies are inferred from the claim text.