(19)
(11) EP 0 140 330 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
22.01.1986 Bulletin 1986/04

(43) Date of publication A2:
08.05.1985 Bulletin 1985/19

(21) Application number: 84112780

(22) Date of filing: 23.10.1984
(84) Designated Contracting States:
DE FR GB IT NL

(30) Priority: 31.10.1983 JP 20265383

(71) Applicant: KABUSHIKI KAISHA TOSHIBA
 ()

(72) Inventors:
  • Nieda, Yasuhiro c/o Patent Division
     ()
  • Honda, Kiyokazu c/o Patent Division
     ()

   


(54) Miniature incandescent lamp


(57) A miniature incandescent lamp of high luminous efficacy and long life has a glass bulb (1) filling an inert gas therein and a coiled filament (2) arranged in the bulb (1), the inert gas containing xenon and nitrogen. A content of xenon in the inert gas is not less than 80% by volume, and a ratio p/d of a coil pitch p of the coiled filament (2) to a wire diameter d is not less than 1.4.






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