Optical imaging transmitter with brightness enhancement

Abstract

An optical system for performing distance measurements comprising: a bulk transmitter optic having a focal plane; an illumination source comprising a plurality of light emitters aligned to project discrete beams of light through the bulk transmitter optic into a field ahead of the optical system; and a micro-optic channel array disposed between the illumination source and the bulk transmitter optic, the micro-optic channel array defining a plurality of micro-optic channels, each micro-optic channel including a micro-optic lens spaced apart from a light emitter in the plurality of light emitters with the micro-optic lens positioned to receive a light cone from the light emitter and configured to generate a reduced-size spot image of the emitter at a location that is displaced from the emitter and that coincides with the focal plane of the bulk transmitter optic

1 . (canceled) 
     
     
         2 . (canceled) 
     
     
         3 . (canceled) 
     
     
         4 . An imaging system, comprising:
 a stationary housing having an optically transparent window;   an imaging device rotatably mounted within the housing, the imaging device comprising:
 a platform; 
 a bulk receiver optic mounted on the platform and configured to receive light rays originating from a field external to the optical system; and 
 an optical assembly mounted on the platform, the optical assembly having a plurality of micro-optic receiver channels defining a plurality of discrete, non-overlapping fields of view in the field, the optical assembly comprising:
 an aperture layer having a plurality of discrete apertures arranged along a focal plane of the bulk receiver optic; 
 an array of photosensors disposed behind the aperture layer; and 
 a non-uniform optical filter layer configured to allow different micro-optic channels to measure different characteristics of incident light; 
 
 wherein the optical assembly further comprises a plurality of lenses, each channel further including a lens from the plurality of lenses, and wherein the lens for each channel is axially aligned with and configured to collimate lights rays received through its corresponding aperture and pass the collimated light rays into its corresponding photosensor; 
   a motor disposed within the housing and operatively coupled to rotate the platform in a scanning direction; and   a system controller disposed within the housing, the system controller being configured to control the motor and to start and stop operations of the photosensors such that a same area in the field is measured by different micro-optic receiver channels at different times.   
     
     
         5 . The imaging system set forth in  claim 4  wherein the non-uniform optical filter comprises a graduated optical filter. 
     
     
         6 . The imaging system set forth in  claim 5  wherein the graduated optical filter gradually increases in thickness in one dimension. 
     
     
         7 . The imaging system set forth in  claim 5  wherein the graduated optical filter increases in thickness in a step-wise fashion in one dimension such that each channel has a constant optical filter layer thickness, but wherein the thicknesses for different micro-optic channels are different. 
     
     
         8 . The imaging system set forth in  claim 4  wherein the non-uniform optical filter allows different micro-optic receiver channels to detect different ranges of wavelengths. 
     
     
         9 . The imaging system set forth in  claim 8  wherein the range of allowed wavelengths changes in a step-wise fashion. 
     
     
         10 . The imaging system set forth in  claim 4  wherein the micro-optic receiver channels are arranged in two-dimensional array and wherein the non-uniform optical filter is non-uniform along the scanning direction. 
     
     
         11 . The imaging system set forth in  claim 4  wherein the array of photosensors comprises an array of photodetectors with each photodetector comprising an array of single-photon avalanche detectors (SPADs). 
     
     
         12 . The imaging system set forth in  claim 4  wherein each channel includes an aperture from the plurality of discrete apertures, and a photosensor in the array of photosensors. 
     
     
         13 . The imaging system set forth in  claim 4  wherein the lens for each channel is configured as a hemisphere positioned along a path of light from the bulk receiver optic, wherein the optical filter is coated on a curved surface of the lens.