High lumen output fluorescent lamp with high color rendition

Abstract

A high lumen output compact fluorescent lamp is disclosed that has a luminous efficiency of 40 lumen/W or higher. The fluorescent lamp comprises an envelope enclosing a discharge space, means for providing a discharge in the discharge space, a discharge gas sealed in the discharge space and a fluorescent layer made of a phosphor blend coated on the inner surface of the envelope. The phosphor blend comprises a, 55 to 80 weight % of a first phosphor 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, b, 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, c, 0 to 20 weight % of a third phosphor 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, and d, 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. The lamp havs an Rvalue greater than 90 and a photographic color temperature between 3000 K and 3500 K. A lamp is also disclosed in which the phosphor blend comprises: a, 20 to 60 weight % of a first phosphor 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, b, 20 to 65 weight % of a second phosphor having an emission band with a maximum between 480 nm and 500 nm and having a half-value width of 50 nm to 95 nm, c, 0 to 20 weight % of a third phosphor having an emission band with a maximum between 450 nm and 460 nm and having a half-value width of 40 nm to 65 nm and d, 0 to 30 weight % of a fourth phosphor having an emission band with a maximum between 610 nm and 630 nm and having a half-value width of 1 nm to 10 nm. This lamp has an Rvalue greater than 90 and a photographic color temperature between 5000 K and 6000 K.