Dual-function light guide for lcd backlight

Abstract

A light emitter/sensor includes a lamp, a light sensor, a light guide, and a light controller. The light guide has a pair of opposite ends and is optically-coupled to the lamp and the light sensor at one of the ends. The light guide is configured to convey light emitted from the lamp to the other end of the light guide, and from that other end to the light sensor. The light controller is coupled to the lamp and the light sensor and is configured to flash the lamp and to determine the intensity of light at that other end of the light guide, via the light guide and the light sensor, during an interval between the flashes.

1 - 10 . (canceled) 
     
     
         11 . A handheld communications device, comprising:
 a display device, comprising:
 a display panel; 
 a light guide coupled to the display panel; 
 a light sensor, the light sensor configured to measure an intensity of ambient light, the light guide configured to direct light between the display panel and the light sensor; and 
 a light source, optically coupled to the light guide, the light guide configured to direct light between the display panel and the light source; and 
   a light controller coupled to the display panel and configured to adjust an intensity of light emitted by the light source in accordance with the measured ambient light intensity.   
     
     
         12 . The handheld communications device of  claim 11 , wherein the light sensor and the light source are provided at a common end of the light guide. 
     
     
         13 . The handheld communications device of  claim 11 , further comprising an event notifier, wherein the event notifier comprises the light sensor. 
     
     
         14 . The handheld communications device of  claim 11 , further comprising a user data input device coupled to the light controller, the user data input device comprising a keyboard and a keyboard backlight, wherein the light controller is configured to adjust an intensity of light emitted by the keyboard backlight in accordance with the measured ambient light intensity. 
     
     
         15 . The handheld communications device of  claim 11 , further comprising a housing, wherein the light guide is configured to convey light between the light source and an external surface of the housing. 
     
     
         16 . The handheld communications device of  claim 15 , wherein the light sensor is configured to measure the intensity of light at the external surface via the light guide, and the light controller is configured to adjust the intensity of emitted light in accordance with the measured external light intensity. 
     
     
         17 . The handheld communications device of  claim 11 , wherein the light source comprises a plurality of backlight LEDs. 
     
     
         18 . The handheld communications device of  claim 11 , wherein the light guide is a planar light guide. 
     
     
         19 . A method of illuminating information rendered on a display device of a handheld communications device, the display device comprising a display panel, a light guide coupled to the display panel, a light sensor, the light sensor configured to measure an intensity of ambient light, the light guide configured to direct light between the display panel and the light sensor, and a light source, optically-coupled to the light guide, the light guide configured to direct light between the display panel and the light source, the method comprising the steps of:
 measuring an intensity of ambient light using the light sensor; and   adjusting an intensity of light emitted by the light source in accordance with the measured ambient light intensity.   
     
     
         20 . The method of  claim 19 , wherein the light sensor and the light source are provided at a common end of the light guide. 
     
     
         21 . The method of  claim 19 , wherein the handheld communications device further comprises an event notifier, wherein the event notifier comprises the light sensor. 
     
     
         22 . The method of  claim 19 , wherein the handheld communications device further comprises a user data input device, the user data input device comprising a keyboard and a keyboard backlight, and wherein the intensity adjusting step further comprises adjusting an intensity of light emitted by the keyboard backlight in accordance with the measured ambient light intensity. 
     
     
         23 . The method of  claim 19 , wherein the handheld communications device further comprises a housing, and wherein the intensity measuring step further comprises measuring the intensity of light external to the housing via the light guide and the light sensor. 
     
     
         24 . The method of  claim 23 , wherein the intensity adjusting step further comprises adjusting the intensity of emitted light in accordance with the measured external light intensity. 
     
     
         25 . The method of  claim 19 , wherein the light source comprises a plurality of backlight LEDs. 
     
     
         26 . The method of  claim 19 , wherein the light guide is a planar light guide.