Abstract: According to one embodiment, a luminaire includes a light source that generates heat, a dome inside of which the light source is accommodated, and a globe covering the light source through the dome. At least part of the dome and at least part of the globe are translucent or transparent. A liquid is sealed in a space formed between the dome and the globe.

Abstract: A high-pressure discharge lamp includes a luminous tube, an outer bulb housing the luminous tube, and a diffusing film formed on at least one of inner and outer surfaces of the outer bulb, in which the diffusing film includes first silica particles having shapes different in surface curvature from each other and hollow second silica particles.

Abstract: A fluorescent lamp comprises a glass tube having the glass tube diameter of 12-20 mm which is formed on an endless shape as a whole by being partially folded, the protective coating formed on the inner wall of the glass tube, the coating containing a mixture of large particles with a mean particle size not less than 1.0 ?m and fine particles with a mean particle size in the range of 10 to 100 nm, a phosphor coating formed on the protective coating, a pair of electrodes mounted in both ends of the glass tube, and a discharge medium filled in the glass tube.

Abstract: A high-pressure discharge lamp which includes a translucent ceramic discharge vessel having a swollen portion defining a discharge space and a pair of cylindrical portions formed in and communicating with the swollen portion and extending from the swollen portion in the opposite directions with each other. The high-pressure discharge lamp also includes metal tubes each having a outer diameter D and fit with its one end on the cylindrical portion, a pair of fusible metal plugs each plugged in the outer end of the metal tube, the fusible metal plug sealing the discharge vessel by being fused to the inner surface of the metal tube for a specified height T from the outer end of the metal plug, a pair of electrode systems each supported its one end to the fusible metal plug and facing the interior of swollen portion with its other end, and ionizing filling filled in the discharge vessel The ratio T/D of the height T concerning the fusible metal plug and the diameter D satisfies the following equation 0.

Abstract: The invention provides the high-intensity discharge lamp and the high-intensity discharge lamp lighting system and the lighting system using the high-intensity discharge lamp showing the low enough starting voltage. The high-intensity discharge lamp comprising a lighting-source bulb provided with an enclosure, a light-transmissive ceramic enclosure defining a pair of small-diameter cylinders communicating with the enclosure at both ends thereof, a pair of electrodes and discharge agent, a metallic coil which is wound on the outside surface of at least one small-diameter cylinder and coupled to the other end of the electrode to have the same potential with the electrode, a jacket-bulb which hermetically accommodates therein the lighting-source bulb and the metallic coil, and a pair of outer lead terminals which are coupled to the pair of electrodes and hermetically led outside the jacket-bulb.

Abstract: The invention provide a high-pressure discharge lamp comprising a translucent ceramic discharge vessel having a swollen portion defining a discharge space and a pair of cylindrical portions formed in communicating with the swollen portion and extending from the swollen portion in the opposite directions with each other, metal tubes each having a outer diameter D and fit with its one end on the cylindrical portion, a pair of fusible metal plugs each plugged in the outer end of the metal tube, the fusible metal plug sealing the discharge vessel by being fused to the inner surface of the metal tube for a specified height T from the outer end of the metal plug, a pair of electrode systems each supported its one end to the fusible metal plug and facing the interior of swollen portion with its other end, and ionizing filling filled in the discharge vessel, wherein the ratio T/D of the height T concerning the fusible metal plug and the diameter D satisfies the following equation.

Abstract: The invention provides the high-intensity discharge lamp and the high-intensity discharge lamp lighting system and the lighting system using the high-intensity discharge lamp showing the low enough starting voltage. The high-intensity discharge lamp comprising a lighting-source bulb provided with an enclosure, a light-transmissive ceramic enclosure defining a pair of small diameter cylinders communicating with the enclosure at both ends thereof, a pair of electrodes and discharge agent, a metallic coil which is wound on the outside surface of at least one small-diameter cylinder and coupled to the other end of the electrode to have the same potential with the electrode, a jacket-bulb which hermetically accommodates therein the lighting-source bulb and the metallic coil, and a pair of outer lead terminals which are coupled to the pair of electrodes and hermetically led outside the jacket-bulb.