Abstract: A ceramic metal halide lamp is provided in which color rendering properties, especially a special color rendering index R9, are improved without causing lamp efficiency to be lowered substantially. In one aspect, a ceramic metal halide lamp includes a luminous tube in the interior of an outer bulb. The luminous tube is made from translucent ceramics and includes a light-emitting portion into which metal halides, mercury and a starting gas are sealed and capillaries with a pair of electrode assemblies extended thereto disposed at both ends of the light-emitting portion. The light-emitting portion has sealed therein at least thulium iodide (TmI3), thallium iodide (TlI), sodium iodide (NaI) and calcium iodide (CaI2). The light-emitting portion has further sealed therein silver iodide (AgI). A quantity of the AgI falls within a range of 2?(AgI/CaI2)[molar ratio]?5 and within a range of 0<(AgI/TlI)[molar ratio]?10.

Abstract: one spectrum correction filter that changes a spectral characteristic of emission light from the light source, at least one neutral density filter disposed on the same optical axis of the spectrum correction filter, wherein the at least one spectrum correction filter and/or the at least one neutral density filter is tilted so that a travel direction of reflection light reflected from the at least one spectrum correction filter is deviated from the optical axis.

Abstract: A manufacturing method of a ceramic metal halide lamp is provided where electrical characteristics and optical characteristics changed at the first time when the lamp begins to glow can be decreased. An example lamp includes a luminous tube with silver iodide (AgI) enclosed therein with predetermined amounts of mercury, metal halides and rare gas. Luminous flux change is measured by changing AgI/total amount of metal halide (weight ratio). An upper limit of AgI is determined by specifying an upper limit value of AgI/total amount of metal halide (weight ratio) based on an allowable lowering rate of luminous flux. Lamp voltage change is measured by changing AgI/total amount of metal halide. A lower limit of AgI is determined by specifying the AgI/total amount of metal halide based on an allowable lowering rate of lamp voltage. An AgI amount falling between the upper and lower limits is sealed into the luminous tube.