Abstract: A high-intensity discharge lamp including an arc tube provided with a heat-resistant translucent discharge vessel forming a discharge space, an electrode structure, a discharge medium charged in the discharge vessel, the discharge medium being composed of a light-emitting metal including mercury and a starting gas, a support member electrically connected with the electrode structure of the arc tube and holding the arc tube and an outer bulb having the arc tube disposed therein along a tube axis and sealed with a support member at an end portion thereof. The electrode structure has an electrode shaft hermetically sealed at each of opposed end portions of the discharge vessel and having a tip portion disposed in the discharge vessel, a coiled electrode wound around the tip portion of the electrode shaft disposed in the discharge vessel, and a recessed portion or a protruding portion formed on the electrode shaft spaced from the coiled electrode.

Abstract: A high-intensity discharge lamp connected to a lighting device has various superior emission properties such as efficiency. The discharge lamp includes a translucent ceramic discharge vessel, in which a pair of electrodes and a discharge medium are inserted. The lamp further includes an outer jacket, in which the arc tube is disposed, and a pair of feeder members. The discharge medium has metal halides including those of Na, Tl and Tm or Na, Tl, In and Tm, and the ratio (MTm/M) of the weight of the gross sealed mass M of the metal halides to the filled mass MTm of the Tm halide is about 0.4?MTm/M?0.9. The deviation in chromaticity (d.u.v.) on the x-y chromaticity coordinates (CIE 1931) for the overall operating position during the life of the lamp is within the range of about ?0.006 to +0.010.

Abstract: A high-intensity discharge lamp connected to a lighting device has various superior emission properties such as efficiency. The discharge lamp includes a translucent ceramic discharge vessel, in which a pair of electrodes and a discharge medium are inserted. The lamp further includes an outer jacket, in which the arc tube is disposed, and a pair of feeder members. The discharge medium has metal halides including those of Na, Tl and Tm or Na, Tl, In and Tm, and the ratio (MTm/M) of the weight of the gross sealed mass M of the metal halides to the filled mass MTm of the Tm halide is about 0.4≦MTm/M≦0.9. The deviation in chromaticity (d.u.v.) on the x-y chromaticity coordinates (CIE 1931) for the overall operating position during the life of the lamp is within the range of about −0.006 to +0.010.