DOUBLE-TUBE TYPE HALOGEN LAMP AND LIGHTING SYSTEM

摘要

PURPOSE:To approximate an external bulb to a lamp and miniaturize an outer shape by reducing the infrared rays emitted to the outside by an infrared ray reflecting film formed in the lamp to the utmost, and suppressing temperature rise of an external bulb. CONSTITUTION:Infrared rays emitted from a halogen lamp l are almost reflected to a filament 6 by an infrared ray reflecting film 8, and part of it is transmitted in the infrared wavelength area. The emitted infrared rays are distributed in a straight line section along the side face of the bulb 2 of the lamp 1. An external bulb 10 made of cylindrical hard glass is arranged to match the straight line section. The heat distribution at the cylinder section of the bulb 10 is made nearly uniform, and the occurrence of distortion in the glass of the bulb 10 due to the heat gradient can be suppressed. The lamp 1 or the filament 6 can be made uniform in temperature in the longitudinal direction, and the occurrence of the local evaporation of tungsten from the filament 6 is suppressed.