Improved method and apparatus for hand-held portable illumination. A
flashlight and corresponding method are described. The flashlight includes
a housing, a plurality of LEDs, and an electrical circuit that selectively
applies power from the DC voltage source to the LED units, wherein the
flashlight is suitable for handheld portable operation by a user. In one
embodiment, the first electrical circuit further includes a control
circuit for maintaining a predetermined light output level of the LED
units as a charge on a battery varies. In another embodiment, the control
circuit maintains an average predetermined light output level of the LED
units as the charge on the battery cell varies by changing a pulse width
or frequency as the charge on the battery cell varies to maintain a given
average light output. Another aspect provides an illumination source that
includes a light-emitting diode (LED) housing including one or more LEDs,
and a control circuit that selectively applies power from a source of
electric power to the LEDs, the control circuit substantially maintaining
a light output characteristic of the LEDs as a voltage of the voltage
source varies over a range that would otherwise vary the light output
characteristic. Still another aspect provides an illumination source
including a light-emitting diode (LED) housing including one or more LEDs;
and a control circuit that selectively applies power from a source of
electric power to the LEDs, thus maintaining or controlling a light output
color spectrum of the LEDs.
Current U.S. Class: | 362/184; 315/224; 315/307; 362/183; 362/157; 315/360; 362/800; 362/159; 315/291; 315/312; 315/362; 362/208; 348/E5.038; 362/249.05; 362/249.06 |
Current CPC Class: |
H04B 10/564 (20130101); H05B 45/395 (20200101); F21L 4/027 (20130101); H05B 45/50 (20200101); H04B 10/502 (20130101); H04N 5/2354 (20130101); H05B 45/12 (20200101); H05B 45/22 (20200101); H05B 45/20 (20200101); Y02B 20/30 (20130101); H05B 45/32 (20200101); Y10S 362/80 (20130101); Y10S 362/802 (20130101); F21Y 2115/10 (20160801) |
Current International Class: |
F21L 4/02 (20060101); F21L 4/00 (20060101); H04N 5/235 (20060101); H04B 10/155 (20060101); H04B 10/152 (20060101); H04B 010/04 () |
Field of Search: |
;362/157,183,159,184,208,800,249 ;315/224,307,291,312,360,362
|