INCANDESCENT LAMP

摘要

In order to provide an incandescent lamp in which an unlit state of the lamp caused by a hang-out of the coil as well as a short lifetime thereof are prevented using a simple construction and its lifetime in practical application is long, a coil (21)-like filament (20) is held in a bulb (11) by upholding parts (30, 30') with an axis of the coil (21) being oriented in a vertical direction, and a coil pitch of the coil (21) at the upper part thereof is made narrow as compared with that of the lower part of the filament (20). Or the filament (20) of the incandescent lamp (10) is constituted by the coil (21) of a conical shape or that of a frustum of a circular cone, and the filament is arranged within the bulb (11) in such a way that it may be held by upholding parts (30, 30') with an axis of the coil (21) of the filament (20) being oriented in a vertical direction and the one end of the coil (21) having a smaller diameter being positioned upward. <IMAGE>