Low profile optical navigation sensor
View Patent ↗An apparatus having a coherent light source, an optical sensor, and a controller that can be utilized in optical mice and the like is disclosed. The coherent light source emits coherent light in a cone of angles about an illumination direction. The optical sensor includes an array of photodetectors disposed on a die having a surface substantially perpendicular to the illumination direction. The controller compares first and second images recorded by the optical sensor at different times and determines a displacement indicative of the direction and distance the apparatus has moved between the two different times. A portion of the coherent light source is bonded to the die at a location within the array of photodetectors.
1. An apparatus comprising:
a coherent light source that emits coherent light in a cone of angles about an illumination direction;
an optical sensor comprising an array of photodetectors disposed on a die having a surface substantially perpendicular to said illumination direction; and
a controller that compares first and second images recorded by said optical sensor at different times and for determining a displacement indicative of the direction and distance said apparatus has moved between said two different times,
wherein a portion of said coherent light source is bonded to said die at a location within said array of photodetectors.
2. The apparatus of claim 1 wherein said coherent light source comprises a semiconductor laser.
3. The apparatus of claim 1 wherein said die comprises said controller.
4. The apparatus of claim 1 wherein said cone of angles has an opening angle between 0 and 45 degrees.
5. The apparatus of claim 1 wherein said coherent light source comprises an optical element that determines said cone of angles.
6. The apparatus of claim 1 further comprising a structure having an enclosed cavity, said die being located on a wall of said cavity.
7. The apparatus of claim 6 wherein said cavity comprises a transparent window in another wall of said cavity, said transparent window being positioned to transmit said coherent light so as to illuminate a surface outside of said apparatus and receive light reflected from that surface.