Light sources utilizing segmented leds to compensate for manufacturing variations in the light output of individual segmented leds

Abstract

A light source and method for making the same are disclosed. The light source includes a plurality of Segmented LEDs connected in parallel to a power bus and a controller. The power bus accepts a variable number of Segmented LEDs. The controller receives AC power and provides a power signal on the power bus. Each Segmented LED is characterized by a driving voltage that is greater than 3 times the driving voltage of a conventional LED fabricated in the same material system as the Segmented LED. The number of Segmented LEDs in the light source is chosen to compensate for variations in the light output of individual Segmented LEDs introduced by the manufacturing process. In another aspect of the invention, the number of Segmented LEDs connected to the power bus can be altered after the light source is assembled.

1 - 15 . (canceled) 
     
     
         16 . A light source comprising:
 a substrate having first and second power rails; and   a plurality of segmented LEDs connected between the first and second power rails,   wherein each segmented LED is configured to generate light when a power signal is applied to the first and second power rails,   wherein each segmented LED comprises a three-layer LED structure disposed on the substrate that includes an n-layer, an active layer on the n-layer, and a p-layer on the active layer, and   wherein each segmented LED is separated by an isolation trench that extends through the n-layer.   
     
     
         17 . The light source of  claim 16 , wherein the plurality of segmented LEDs are provided by a single LED die that is divided into N segments serially connected to each other, with N being >1, and each segmented LED comprises a size that is 1/N times a size of a single junction LED fabricated in a same material as the segmented LED. 
     
     
         18 . The light source of  claim 17 , wherein N is between 2 and 100. 
     
     
         19 . The light source of  claim 16 , wherein each segmented LED requires a driving voltage that is 3 times greater than a driving voltage of a single junction LED in order to generate the light at a predetermined intensity. 
     
     
         20 . The light source of  claim 19 , wherein each segmented LED requires a current that is N times smaller than a current required by the single junction LED to generate the light at the predetermined intensity. 
     
     
         21 . The light source of  claim 19 , wherein each segmented LED requires the driving voltage to be greater than 9.6 volts. 
     
     
         22 . The light source of  claim 16 , wherein each segmented LED is configured to generate light at an intensity that is less than 10% of a total light intensity generated by the light source. 
     
     
         23 . The light source of  claim 16 , further comprising a power bus configured to power a variable number of the plurality of segmented LED, with the power bus including at least one breakable link that is configured to permanently disconnect at least one respective segmented LED from the power bus when said link is broken. 
     
     
         24 . The light source of  claim 23 , wherein the power bus comprises the first and second power rails, and the light source further comprises a controller configured to receive AC power and provide the power signal to the power bus comprising the first and second power rails in response to receiving the AC power. 
     
     
         25 . The light source of  claim 16 , wherein a first portion of the plurality of segmented LEDs are arranged in a first orientation and a second portion of the plurality of segmented LEDs are arranged in a second orientation opposite the first orientation. 
     
     
         26 . A light source comprising:
 a substrate having first and second power conductors; and   a plurality of segmented LEDs connected between the first and second power conductors,   wherein each segmented LED is configured to generate light when a power signal is applied to the first and second power conductors,   wherein each segmented LED comprises a three-layer LED structure disposed on the substrate that includes an n-layer, an active layer on the n-layer, and a p-layer on the active layer, and   wherein each segmented LED is separated by an isolation trench that extends through the n-layer.   
     
     
         27 . The light source of  claim 26 , wherein the first and second power conductors are first and second power rails constructed to accommodate the plurality of segmented LEDs. 
     
     
         28 . The light source of  claim 26 , wherein the plurality of segmented LEDs are provided by a single LED die that is divided into N segments serially connected to each other, with N being >1, and each segmented LED comprises a size that is 1/N times a size of a single junction LED fabricated in a same material as the segmented LED. 
     
     
         29 . The light source of  claim 28 , wherein N is between 2 and 100. 
     
     
         30 . The light source of  claim 26 , wherein each segmented LED requires a driving voltage that is 3 times greater than a driving voltage of a single junction LED in order to generate the light at a predetermined intensity. 
     
     
         31 . The light source of  claim 30 , wherein each segmented LED requires a current that is N times smaller than a current required by the single junction LED to generate the light at the predetermined intensity. 
     
     
         32 . The light source of  claim 26 , wherein each segmented LED is configured to generate light at an intensity that is less than 10% of a total light intensity generated by the light source. 
     
     
         33 . The light source of  claim 26 , further comprising a power bus configured to power a variable number of the plurality of segmented LED, with the power bus including at least one breakable link that is configured to permanently disconnect at least one respective segmented LED from the power bus when said link is broken. 
     
     
         34 . The light source of  claim 33 , wherein the power bus comprises the first and second power rails, and the light source further comprises a controller configured to receive AC power and provide the power signal to the power bus comprising the first and second power rails in response to receiving the AC power. 
     
     
         35 . The light source of  claim 26 , wherein a first portion of the plurality of segmented LEDs are arranged in a first orientation and a second portion of the plurality of segmented LEDs are arranged in a second orientation opposite the first orientation.