US RE40,619 E1
	Efficient fluorescent lighting system
David W. Knoble, Tupelo, Miss. (US); and Eugene Graff, Tupelo, Miss. (US)
Assigned to Genlyte Thomas Group LLC, Louisville, Ky. (US)
Filed on Sep. 13, 2005, as Appl. No. 11/225,841.
Application 11/225841 is a reissue of application No. 10/310665, filed on Dec. 05, 2002, now 6,817,732, filed on Nov. 16, 2004.
Int. Cl. F21S 4/00 (2006.01)

U.S. Cl. 362—225  [362/147; 362/227; 362/217; 362/411; 362/260; 362/221]

15 Claims

[ 18. An improved efficiency fluorescent lighting system having a plurality of luminaires located a first predetermined distance from a surface to be illuminated and spaced apart a second predetermined horizontal spacing distance, each of said luminaires in said system comprising: at least one high efficiency fluorescent lamp retained within said luminaire, said luminaire having a spacing to mounting height ratio of above 1.4; wherein said spacing to mounting height ratio is further defined as the spacing between two luminaires such that the illumination on the floor midway between the two luminaires is equal to the illumination from one luminaire at nadir; and, an electronic ballast having a ballast factor of at least 1.15.]