Extra-high pressure discharge lamp
AssigneeUshio Denki Kabushiki Kaisha
InventorsTakashi Yamashita, Kazuhiro Goto, Kazuhiro Yoshida, Noriko Horikawa
Life of this patent
Estimating the term…
Abstract
An extra-high pressure discharge lamp, comprises an optical transparent light emitting section, sealing sections connected to the light emitting section, a pair of electrodes which face each other in the light emitting section, wherein one of the electrodes having a thick portion, a thin portion and an intermediate portion which is formed between the thick portion and the thin portion, wherein 0.15 mg/mm3 of mercury is enclosed in the light emitting portion, and wherein the number of crystal grains which exist on a cross section perpendicular to an axis of the one of the electrodes is three.
Claims15
An extra-high pressure discharge lamp, comprising:
- an optical transparent light emitting section;
- sealing sections connected to the light emitting section;
- a pair of electrodes which face each other in the light emitting section,
- wherein one of the electrodes having a thick portion, a thin portion and an intermediate portion which is formed between the thick portion and the thin portion,
- wherein 0.15 mg/mm3 of mercury is enclosed in the light emitting portion,
- wherein the number of crystal grains which exist on a cross section perpendicular to an axis of the one of the electrodes is three,
- wherein a distance which connects grain boundaries and which crosses in the diameter direction of the electrode on a cross section thereof taken along an electrode axial direction passing approximately a central axis of the intermediate portion, is twice or more a diameter d of the intermediate portion.
An extra-high pressure discharge lamp comprising:
- an intermediate portion of an electrode between thick and thin portions of the electrode, diameters of the intermediate portion along an axial direction of the electrode decreasing from said thick portion to said thin portion,
- wherein each cross section of the intermediate portion along said axial direction has at least three crystal grains, said each cross section being perpendicular to said axial direction.
Dependencies are inferred from the claim text.