Integrated light concentrator

Abstract

An infrared sensor including an absorber for absorbing incident infrared power to produce a signal representing the temperature of a target object, a frame supporting a membrane which carries the absorber, the frame including a plurality of reflecting surfaces disposed about the circumference of an opening over which the membrane spans for reflecting incident infrared power toward the absorber. By concentrating incident infrared power through reflection, the temperature difference between the absorber and the surrounding frame is increased, thereby producing an increased electrical output from the sensor.

1 . An infrared sensor, including: 
 an absorber for absorbing incident infrared power to produce a signal representing the temperature of a target object, the absorber defining a perimeter;    a frame defining a plurality of reflecting surfaces for reflecting incident infrared power toward the absorber, wherein the reflecting surfaces define a light collecting region comprising a cavity having a substantially rectangular cross section, each of the reflecting surfaces being coated with a metal film and disposed at an obtuse angle relative to the light collecting region; and    a membrane contiguously disposed on the frame and spanning the light collecting region, the absorber being disposed in a central region of the membrane, the membrane defining membrane borders extending between the perimeter of the absorber and the plurality of reflecting surfaces, and thermally isolating the absorber from the frame,    wherein the frame includes a body for supporting the membrane and the absorber and a light concentrator attached to the body, the reflecting surfaces being disposed on the light concentrator.    
   
   
       2 . The infrared sensor of  claim 1  further including a plurality of series connected thermocouples, each of the thermocouples extending between the frame and the absorber.  
   
   
       3 . The infrared sensor of  claim 1  wherein each of the reflecting surfaces is coated with a metal film.  
   
   
       4 . The infrared sensor of  claim 1  wherein the reflecting surfaces define a cavity having a substantially rectangular cross section.  
   
   
       5 . The infrared sensor of  claim 1  wherein the frame includes a body for supporting the membrane and the absorber and a light concentrator attached to the body, the reflecting surfaces being disposed on the light concentrator.  
   
   
       6 . The infrared sensor of  claim 1  further including a circuit board having a void, the frame being mounted to the circuit board such that the absorber is disposed adjacent the void.  
   
   
       7 . The infrared sensor of  claim 1  wherein the frame defines a rectangular opening having a perimeter, the frame including four segments disposed about the perimeter, each of the segments having an inner side defining one of the reflecting surfaces.