High efficiency LED lamp

An LED lamp comprising:

• an LED assembly including at least first and second LEDs operable to emit light of at least two different colors;
• a cylindrical optical element disposed to receive light from the LED assembly, the optical element including a cylindrical curved surface defining a first end and a second end and a primary exit surface through which light exist the LED lamp, the primary exit surface closing the first end of the cylindrical curved surface and being substantially flat over its entire area, and the primary exit surface spaced at least about 1.5 inches from the LED assembly;
• and a flat, white reflective, annular-shaped member surrounding and external to the optical element and the LED assembly, the flat, white reflective, annular shaped member being disposed adjacent the second end and being exposed to light emitted from the optical element to reflect the light;
• wherein the lamp produces at least 170 Lumens/Watt.

A method of assembling a high-efficiency LED lamp, the method comprising:

• providing an LED assembly comprising a plurality of LEDs mounted on a flat carrier;
• connecting the LED assembly to a line-voltage power supply;
• providing a heatsink in thermal communication with at least one of the line-voltage power supply and the LED assembly;
• installing a flat, white reflective, annular-shaped member adjacent to the heatsink;
• and
• installing a cylindrical optical element disposed to receive light from the LED assembly, the optical element including a cylindrical surface defining a first end and a second end and a primary exit surface through which light exits the LED lamp, the primary exit surface closing the first end of the cylindrical surface and being substantially flat over its entire area and being substantially parallel to the carrier over its entire area, the optical element being positioned so that the flat, reflective, white reflective, annular-shaped member is external to and surrounds the optical element adjacent the second end and is exposed to light emitted from the diffuser to reflect the light., the primary exit surface also positioned so that the primary exit surface is spaced at least about 1.5 inches from the LED assembly wherein the lamp produces at least 170 Lumens/Watt.

An LED lamp comprising:

• a plurality of LEDs mounted on a flat carrier, wherein the plurality of LEDS comprises at least two groups of LEDs, wherein one group, when illuminated, emits light having a dominant wavelength from 435 to 490 nm, and another group, when illuminated, emits light having a dominant wavelength from 600 to 640 nm, one group being packaged with a phosphor, which, when excited, emits light having a dominant wavelength from 540 to 585 nm, the plurality of LEDs each having a square area of approximately 2.0 mm2;
• a heat sink thermally coupled to the plurality of LEDs;
• a diffuser including a curved cylindrical surface defining a first end and a second end and a primary exit surface through which light exits the LED lamp, the primary exit surface closing the first end of the curved cylindrical surface and being substantially parallel to the carrier over its entire area such that a primary portion of the light from the plurality of LEDs reflects off of the cylindrical surface and exits the lamp through the primary exit surface, the primary exit surface spaced at least 1.5 inches from the LED assembly;
• and
• a flat, reflective, annular-shaped member surrounding and external to the diffuser, the flat, reflective, annular-shaped member being disposed adjacent the second end for reflecting light emitted from the diffuser,
• whereby the lamp produces at least 1200 Lumens with a CRI of at least 90 with a luminous efficacy of at least 170 Lumens per Watt.