Abstract: A ceramic metal-halide lamp is provided that can improve both lamp efficacy and color characteristics, and in which light color shift from the white region can be prevented when the lamp is dimmed. The lamp includes a luminous material, which contains sodium iodide (NaI), cerium iodide (CeI3), thallium iodide (TIl), dysprosium iodide (DyI3) and indium iodide (InI). The amount D[DyI3] of dysprosium iodide DyI3 is selected so as to fall within a range of 0.07 mg/cm3?D[DyI3]?1.53 mg/cm3 and a weight ratio R[InI/TIl] of indium iodide InI relative to thallium iodide TIl contained in the luminous material is selected to so as to fall within a range of 0<R[InI/TIl]?0.23.

Abstract: A high watt type ceramic metal halide lamp illumination device is provided. The device comprises: ballast receiving a primary input voltage and outputting a secondary voltage, and a lamp having a plurality of arc tubes electrically connected in series inside an outer bulb. The lamp is lighted by receiving the secondary voltage output from the ballast. The secondary voltage output from the ballast has a waveform that at least satisfies a maximum-value to effective-value ratio (Vmax/Veff) of greater than 20.5. When using two 360 W arc tubes of a popular type by electrically connecting the two in series instead of a 700 W arc tube of a high-watt type, for example, it is preferable to use a triangular waveform AC voltage that satisfies 260?Veff(triangular waveform) when expressed by the effective-value, and 500 V?Vmax(triangular waveform) when expressed by the maximum-value.

Abstract: Aspects of the disclosure include a ceramic metal halide lamp in which two arc tubes are arranged electrically in series inside the same outer globe. By arranging the two arc tubes in such a way that light-emitting parts thereof do not overlap, decline in lifespan due to the heat of one arc tube causing the temperature of the other arc tube to increase and lighting failure due to an increase in lamp voltage do not occur. And by setting the distance from an electrode tip at a base side of the first arc tube to an electrode tip at a lamp-top side of the second arc tube to be equal to or less than 3.5 times the average inter-electrode distance of both arc tubes, a preferable distribution of light is implemented.

Abstract: A ceramic metal-halide lamp is provided that can improve both lamp efficacy and color characteristics, and in which light color shift from the white region can be prevented when the lamp is dimmed. The lamp includes a luminous material, which contains sodium iodide (NaI), cerium iodide (CeI3), thallium iodide (TIl), dysprosium iodide (DyI3) and indium iodide (InI). The amount D[DyI3] of dysprosium iodide DyI3 is selected so as to fall within a range of 0.07 mg/cm3?D[DyI3]?1.53 mg/cm3 and a weight ratio R[InI/TIl] of indium iodide InI relative to thallium iodide TIl contained in the luminous material is selected to so as to fall within a range of 0<R[InI/TIl]?0.23.

Abstract: High color rendition (Ra?80) and high efficiency (??100 (1 m/W)) which are effects conflicting to each other in a metal halide lamp are attained. An arc tube formed of translucent ceramics, capillaries are formed continuously on the both ends of an arc chamber formed substantially in an ellipsoidal shape in the direction of the longitudinal axis by way of a transition curve with no angled corner, and the arc tube is designed to effective length L/effective inner diameter D of 1.8 to 2.2, and formed to such a size that the lowest temperature of the arc chamber is 800° C. or higher and the highest temperature of the arc chamber is 1200° C. or lower during lighting, and at least thulium iodide, thallium iodide, sodium iodide, and calcium iodide are sealed as metal halides where sodium iodide and calcium iodide are sealed by a molar ratio of 40 to 80% and less than 30%, respectively, based on the entire metal halides.

Abstract: A metal halide lamp capable of delaying the rate of deformation in an electrostrictive phenomenon caused by the discharge of a ferroelectric ceramic capacitor when dielectric breakdown is initiated between the electrodes of an arc tube thereby preventing breakage accident, wherein a starting circuit, housed in parallel connection together with an arc tube in an outer tube of a metal halide lamp has in serial connection, a ferroelectric ceramic capacitor that is charged and discharged when a voltage at a predetermined coercive voltage or higher is applied thereby outputting a starting pulse at a high voltage from a ballast, a semiconductor switch that turns to a conduction state when a voltage of a predetermined breakover voltage or higher is applied, and a time constant control resistor that delays the discharge time of electric charges discharged from the capacitor when dielectric breakdown is initiated in the arc tube.

Abstract: High color rendition (Ra?80) and high efficiency (??100 (1 m/W)) which are effects conflicting to each other in a metal halide lamp are attained. An arc tube formed of translucent ceramics, capillaries are formed continuously on the both ends of an arc chamber formed substantially in an ellipsoidal shape in the direction of the longitudinal axis by way of a transition curve with no angled corner, and the arc tube is designed to effective length L/effective inner diameter D of 1.8 to 2.2, and formed to such a size that the lowest temperature of the arc chamber is 800° C. or higher and the highest temperature of the arc chamber is 1200° C. or lower during lighting, and at least thulium iodide, thallium iodide, sodium iodide, and calcium iodide are sealed as metal halides where sodium iodide and calcium iodide are sealed by a molar ratio of 40 to 80% and less than 30%, respectively, based on the entire metal halides.

Abstract: A metal halide lamp capable of delaying the rate of deformation in an electrostrictive phenomenon caused by the discharge of a ferroelectric ceramic capacitor when dielectric breakdown is initiated between the electrodes of an arc tube thereby preventing breakage accident, wherein a starting circuit, housed in parallel connection together with an arc tube in an outer tube of a metal halide lamp has in serial connection, a ferroelectric ceramic capacitor that is charged and discharged when a voltage at a predetermined coercive voltage or higher is applied thereby outputting a starting pulse at a high voltage from a ballast, a semiconductor switch that turns to a conduction state when a voltage of a predetermined breakover voltage or higher is applied, and a time constant control resistor that delays the discharge time of electric charges discharged from the capacitor when dielectric breakdown is initiated in the arc tube.