Abstract: In a discharge bulb having an arc tube formed with pinch seal portions on both ends of a sealed glass bulb that is a light-emitting discharge section, infrared transmitting films for blocking visible light and transmitting infrared light are applied to at least the pinch seal portions of the arc tube to prevent visible light from exiting the pinch seal portions and to suppress generation of glare. Infrared light from the pinch seal portions can pass through the infrared transmitting films, which prevents accumulation of heat in the arc tube (pinch seal portions and sealed glass bulb), thereby preventing the temperature of the arc tube from increasing excessively.

Abstract: An insulating plug, for a discharge lamp device, including a plug body and a lamp-side connector. The plug body is made of a glass-fiber-reinforced plastic resin. The lamp-side connector is provided at a rear end portion of the plug body. A power-supplying connector can be attached to, and detached from, the lamp-side connector. The plug body has an arc tube fixedly held thereon, so as to form a discharge lamp device. Because the plug body is made of a glass-fiber-reinforced plastic resin, the durability, molding precision, and so on of the plug body and, hence, those of the discharge lamp device provided with this plug body, are enhanced.