Patent ID: 7138757

Claim:
A high lumen output compact fluorescent lamp having a luminous efficiency of 40 lumen/W or higher, comprising an envelope enclosing a discharge space, means for providing a discharge in the discharge space, a discharge gas sealed in the discharge space, a fluorescent layer made of a phosphor blend coated on the inner surface of said envelope, the phosphor blend comprising 55 to 65 weight % of a first phosphor which is (Sr,Mg) 3 (PO 4 ) 2 :Sn having an emission band with a maximum between 620 nm and 635 nm and having a half-value width of 70 nm to 150 nm, 5 to 30 weight % of a second phosphor having an emission band with a maximum between 605 nm and 615 nm and having a half-value width of 1 nm to 10 nm, 2 to 10 weight % of a third phosphor which is LaPO 4 :Ce,Tb having an emission band with a maximum between 540 nm and 550 nm and having a half-value width of 1 nm to 10 nm, 0 to 30 weight % of a fourth phosphor having an emission band with a maximum between 480 nm and 500 nm and having a half-value width of 50 nm to 80 nm, said lamp having an R a value greater than 90 and a photographic color temperature between 3000K and 3500K.