| 摘要 |
PROBLEM TO BE SOLVED: To even the distribution of temperature, and cope with various lamp attitudes, and make possible the applying to a single base lamp by forming each dimension of a cylindrical discharge lamp, which has a spherical terminal part in both ends thereof, so as to satisfy the specified relation of distance. SOLUTION: An inner chamber, which includes the light emitting sealing material, of a discharge lamp 1 is formed of a cylindrical central part 2 having length at L and nearly spherical terminal parts 3, 3, which respectively have the same radius R with the central part 2, in both sides of the central part 2, and a space between both the electrodes is expressed with EA. The terminal part 3 is formed with a cylindrical projecting part 4, in which a ceramics plug 5 is to be fitted. In this structure, L, R, EA are set so as to satisfy the relation that L<=R, and desirably, L<=0.8R, and 2R+L>=1.1EA and 1.5EA>=2R>=0.8EA. With this structure, a photometry lamp data nearly equal to a case of a long cylindrical or an elliptic discharge lamp is obtained, and furthermore, distribution of temperature is evened by lowering of hot-spot temperature. Desirably, both ends of the discharge lamp are provided with a ceramics plug for housing a bushing. |
