Patent Number: 6,683,413

Title: High pressure discharge lamp of the short arc type

Abstract: The object of the invention is to improve the thermal radiation characteristic of the electrodes in a high pressure discharge lamp of the short arc type in which the input power has been increased in order to increase the amount of radiant light, and to reduce the electrode temperature with high efficiency. The object is achieved as claimed in the invention in a high pressure discharge lamp of the short arc type in the emission tube of which there is a pair of electrodes, in that at least part of the sides of the above described electrodes is provided with a groove area, that the depth D of this groove area is within 12% of the electrode diameter and that the relation D/P is between the depth D of the groove area and the pitch P between the grooves is greater than or equal to 2.

Inventors: Okubo; Keisuke (Himeji, JP), Ikeuchi; Mitsuru (Himeji, JP), Miyanaga; Shoji (Takasago, JP)

Assignee: Ushiodenki Kabushiki Kaisha

International Classification: H01J 61/86 (20060101); H01J 61/06 (20060101); H01J 61/073 (20060101); H01J 61/84 (20060101); H01J 061/073 ()

Expiration Date: 01/27/2021