Visible light sensor configured for detection of glare conditions

Abstract

A device may be configured to detect a glare condition and may comprise a photo sensing circuit and a visible light sensing circuit. The photo sensing circuit may be configured to periodically generate an illuminance signal that indicates an illuminance value. The visible light sensing circuit may be configured to periodically record images of the space at an exposure time. The device may receive an illuminance signal from the photo sensing circuit and determine a present illuminance based on the illuminance signal. The device may adjust the frequency at which the visible light sensing circuit records images based on the present illuminance. The exposure time may be determined based on the present illuminance and a glare condition type. An image recorded at a respective exposure time may wash out pixels above a certain illuminance value. The device may detect a glare condition at the location of washed out pixels.

What is claimed is: 
     
         1 . (canceled) 
     
     
         2 . A device for detecting a glare condition in a space, the device comprising:
 a photo sensing circuit configured to generate an illuminance signal;   a visible light sensing circuit configured to record at least one image to detect a glare condition; and   a control circuit configured to:
 receive the illuminance signal from the photo sensing circuit, 
 determine a likelihood of detecting the glare condition based on the illuminance signal; 
 enable the visible light sensing circuit to record the at least one image when the illuminance signal indicates a likelihood of detecting the glare condition; and 
 process, based on the illuminance signal indicating the likelihood of detecting the glare condition, the at least one image recorded by the visible light sensing circuit to detect the glare condition. 
   
     
     
         3 . The device of  claim 2 , wherein the control circuit being configured to determine the likelihood of detecting the glare condition further comprises the control circuit being configured to determine a present illuminance value based on the illuminance signal. 
     
     
         4 . The device of  claim 3 , wherein the control circuit is configured to enable the visible light sensing circuit to record at least one image when the illuminance value exceeds a threshold. 
     
     
         5 . The device of  claim 2 , wherein the visible light sensing circuit is configured to periodically record images based on the illuminance signal indicating the likelihood of detecting the glare condition. 
     
     
         6 . The device of  claim 5 , wherein the visible light sensing circuit is configured to stop periodically recording images based on the illuminance signal not indicating the likelihood of detecting the glare condition. 
     
     
         7 . The device of  claim 2 , wherein the control circuit is configured to process the at least one image recorded by the visible light sensing circuit to detect the glare condition at a processing frequency. 
     
     
         8 . The device of  claim 7 , wherein the control circuit is configured to:
 calculate a difference between a present illuminance value based on the illuminance signal and a previous illuminance value to determine a change in illuminance; and   adjust the processing frequency based on the change in illuminance.   
     
     
         9 . The device of  claim 8 , wherein the control circuit is configured to increase the processing frequency when the change in illuminance is greater than a first threshold, and to decrease the processing frequency when the change in illuminance is less than a second threshold. 
     
     
         10 . The device of  claim 2 , wherein the photo sensing circuit consumes less power than the visible light sensing circuit. 
     
     
         11 . A method for detecting a glare condition in a space, the method comprising:
 generating an illuminance signal;   recording at least one image to detect a glare condition; and   determining a likelihood of detecting the glare condition based on the illuminance signal;   recording the at least one image when the illuminance signal indicates a likelihood of detecting the glare condition; and   processing, based on the illuminance signal indicating the likelihood of detecting the glare condition, the at least one image recorded by the visible light sensing circuit to detect the glare condition.   
     
     
         12 . The method of  claim 11 , further comprising determining the likelihood of detecting the glare condition by determining a present illuminance value based on the illuminance signal. 
     
     
         13 . The method of  claim 12 , further comprising enabling the visible light sensing circuit to record at least one image when the illuminance value exceeds a threshold. 
     
     
         14 . The method of  claim 11 , further comprising periodically recording images based on the illuminance signal indicating the likelihood of detecting the glare condition. 
     
     
         15 . The method of  claim 14 , further comprising stopping periodically recording images based on the illuminance signal not indicating the likelihood of detecting the glare condition. 
     
     
         16 . The method of  claim 11 , further comprising processing the at least one image recorded by the visible light sensing circuit to detect the glare condition at a processing frequency. 
     
     
         17 . A computer-readable storage medium having instructions stored thereon, that when executed by a control circuit, cause the control circuit to:
 determine a likelihood of detecting a glare condition based on an illuminance signal;   record at least one image when the illuminance signal indicates a likelihood of detecting the glare condition; and   process, based on the illuminance signal indicating the likelihood of detecting the glare condition, the at least one image to detect the glare condition.   
     
     
         18 . The computer-readable storage medium of  claim 17 , wherein the instructions, when executed, further cause the control circuit to determine the likelihood of detecting the glare condition by being configured to cause the control circuit to determine a present illuminance value based on the illuminance signal. 
     
     
         19 . The computer-readable storage medium of  claim 18 , wherein the instructions, when executed, further cause the control circuit to record the at least one image when the illuminance value exceeds a threshold. 
     
     
         20 . The computer-readable storage medium of  claim 17 , wherein the instructions, when executed, further cause the control circuit to periodically record images based on the illuminance signal indicating the likelihood of detecting the glare condition. 
     
     
         21 . The computer-readable storage medium of  claim 20 , wherein the instructions, when executed, further cause the control circuit to stop periodically recording images based on the illuminance signal not indicating the likelihood of detecting the glare condition.