Laser energy integrator for display waveguide breakage safety system

Abstract

Systems and methods for implementing a continuously monitoring safety system that tracks emission of light energy from the light source by measuring energy at various sampling points within image frames projected by a projector and estimating a highest energy for a pupil area of each of the image frames based on a subset of sampling points encompassed by the pupil area. The highest energy for each of the image frames is summed to generate a cumulative highest energy, which is compared to a predetermined threshold, and in response to the cumulative highest energy exceeding the threshold, adjusting an power output of the projector.

1 - 20 . (canceled) 
     
     
         21 . A method comprising:
 adding a highest estimated energy for a pupil area at each of a plurality of sampling points projected by a projector for each of a plurality of image frames to generate a cumulative highest energy;   comparing the cumulative highest energy to a threshold; and   in response to the cumulative highest energy exceeding the threshold, adjusting a power output of the projector.   
     
     
         22 . The method of  claim 21 , wherein the threshold is based on a maximum allowable energy output for Class 1 laser light. 
     
     
         23 . The method of  claim 22 , wherein adjusting the power output of the projector comprises sending a signal to the projector to reduce the power output of the projector. 
     
     
         24 . The method of  claim 22 , wherein adjusting the power output of the projector comprises sending a signal to the projector to adjust content of the plurality of image frames. 
     
     
         25 . The method of  claim 21 , wherein adjusting the power output of the projector comprises sending a signal to the projector to turn off. 
     
     
         26 . The method of  claim 21 , further comprising:
 in response to the cumulative highest energy not exceeding the threshold, determining whether a predetermined time has elapsed.   
     
     
         27 . The method of  claim 26 , further comprising:
 in response to determining that the predetermined time has elapsed, measuring energy in a next image frame within the plurality of image frames.   
     
     
         28 . A system comprising:
 a projector configured to emit light forming a plurality of image frames; and   a safety system configured to:
 generate a cumulative highest energy by adding an estimated highest energy for a pupil area at each of a plurality of sampling points projected by the projector for each of the plurality of image frames; 
 compare the cumulative highest energy to a threshold; and 
 in response to the cumulative highest energy exceeding the threshold, adjusting the light emitted from the projector. 
   
     
     
         29 . The system of  claim 28 , wherein the threshold is based on a maximum allowable energy output for Class 1 laser light. 
     
     
         30 . The system of  claim 29 , wherein adjusting the light emitted from the projector comprises sending a signal to the projector to reduce a power output from the projector. 
     
     
         31 . The system of  claim 29 , wherein adjusting the light emitted from the projector comprises sending a signal to the projector to adjust content of the plurality of image frames. 
     
     
         32 . The system of  claim 28 , wherein adjusting the light emitted from the projector comprises sending a signal to the projector to turn off. 
     
     
         33 . The system of  claim 28 , further comprising:
 in response to the cumulative highest energy not exceeding the threshold, determining whether a predetermined time has elapsed.   
     
     
         34 . The system of  claim 33 , further comprising:
 in response to determining that the predetermined time has elapsed, measuring energy in a next image frame within the plurality of image frames.   
     
     
         35 . A head-mounted display (HMD) system comprising:
 a projector configured to emit light forming a plurality of image frames; and   a safety system comprising:
 at least one energy monitoring component configured to measure energy of at least a portion of the light emitted from the projector at a plurality of sampling points within the plurality of image frames; 
   a safety processor configured to:
 generate a cumulative highest energy by adding an estimated highest energy for a pupil area at each of a plurality of sampling points projected by the projector for each of the plurality of image frames; 
 compare the cumulative highest energy to a threshold; and 
 send a signal to one of a display controller or the projector in response to the cumulative highest energy exceeding the threshold, the signal conveying instructions to adjust the light emitted from the projector. 
   
     
     
         36 . The HMD of  claim 35 , wherein the threshold is based on a maximum allowable energy output for Class 1 laser light. 
     
     
         37 . The HMD of  claim 36 , wherein the signal conveying instructions to adjust the light emitted from the projector comprises instructions to reduce a power output of the projector. 
     
     
         38 . The HMD of  claim 36 , wherein the signal conveying instructions to adjust the light emitted from the projector comprises instructions to adjust content of the plurality of image frames. 
     
     
         39 . The HMD of  claim 36 , wherein adjusting the light emitted from the projector comprises sending a signal to the projector to shut down. 
     
     
         40 . The HMD of  claim 36  wherein the safety processor is further configured to:
 in response to the cumulative highest energy not exceeding the threshold, determining whether a predetermined time has elapsed; and 
 in response to determining that the predetermined time has elapsed, measuring energy in a next image frame within the plurality of image frames.