Optical modules that reduce speckle contrast and diffraction artifacts

摘要

An optical module, for use in a depth camera, includes a plurality of laser emitting elements, each of which emits a corresponding laser beam, and a micro-lens array (MLA) that includes a plurality of lenslets. Laser beams emitted by adjacent laser emitting elements at least partially overlap one another prior to being incident on the MLA For each lenslet of at least a majority of the lenslets of the MLA, the lenslet is at least partially filled by light corresponding to laser beams emitted by at least two of the laser emitting elements. The inclusion of the plurality of laser emitting elements is used to reduce speckle contrast. The overlap of the laser beams, and the at least partially filling of the lenslets of the MLA with light corresponding to laser beams emitted by multiple laser emitting elements, is used to reduce diffraction artifacts.

主权项

1. A depth camera system for use in obtaining a depth image of a capture area, comprising:
an optical module configured to output infrared (IR) light that illuminates the capture area; an image pixel detector array configured to detect a portion of the IR light, output by the optical module, that has reflected off one or more objects within the capture area and is incident on the image pixel detector array; and a processor configured to produce the depth image based on the portion of the IR light detected by the image pixel detector; wherein the optical module includes
a plurality of laser emitting elements each of which is operable to emit a corresponding IR laser beam, the plurality of laser emitting elements including five or more laser emitting elements; anda micro-lens array including a two-dimensional array of substantially identical lenslets;wherein adjacent ones of the laser emitting elements are configured to emit IR laser beams that at least partially overlap one another prior to being incident on the micro-lens array;wherein for each lenslet of at least a majority of the lenslets in the two-dimensional array of substantially identical lenslets of the micro-lens array, the lenslet is configured to be at least partially filled by IR light corresponding to IR laser beams emitted by at least five of the laser emitting elements;wherein a number of lenlests, in the two-dimensional array of substantially identical lenslets of the micro-lens array, is greater than a number of laser emitting elements;wherein a center-to-center distance between any two of the light emitting elements that are adjacent to one another is less than 100 μm; andwherein a center-to-center distance between any two of the light emitting elements that are not adjacent to one another is less than 1 mm.