Patent ID: 7538479

Claim:
A fluorescent lamp comprising a glass bulb provided with a phosphor film on its internal face, in which a rare gas and an amalgam pellet are enclosed, wherein the amalgam pellet contains zinc, tin, and mercury, one or a plurality of the amalgam pellets are enclosed in the glass bulb, and each of the amalgam pellets has a weight of not more than 20 mg, and the fluorescent lamp satisfies the relationship expressed as: 45×(1 −A )≦ x≦ 55×(1 −A ), 75A≦y≦85A, 45−30 A≦z≦ 55−30 A , and x+y+z≦ 100, where A represents a value whose lower limit is determined as: A≧ 0.3−( S/ 25) and A≧ 0.1 when 0 ≦L 2 /D≦ 1.5×10 4 , A≧ 0.4−( S/ 25) and A≧ 0.2 when 1.5×10 4 <L 2 /D≦ 5×10 4 , or A≧ 0.5−( S/ 25) and A≧ 0.3 when 5×10 4 <L 2 /D≦ 8.5×10 4 , where D represents an internal diameter of the glass bulb in millimeters, L represents a length of a discharge path in millimeters, S represents a surface area of the amalgam pellet in square millimeters, x represents a content of zinc in percent by weight, y represents a content of tin in percent by weight, and z represents a content of mercury in percent by weight.