Described is dynamic control of the temperature of the envelope of an HID lamp in order to stabilize the output color temperature of the lamp. As the lamp power is changed, or environmental factors alter the lamp envelope temperature, the system senses these changes and adjusts the lamp cooling systems so as to move the lamp envelope temperature back to the desired point.

Described is dynamic control of the temperature of the envelope of an HID lamp in order to stabilize the output color temperature of the lamp. As the lamp power is changed, or environmental factors alter the lamp envelope temperature, the system senses these changes and adjusts the lamp cooling systems so as to move the lamp envelope temperature back to the desired point.

In a light-emitting sealed body, a metal structure (electron emission structure) containing an easily electron-emitting material is used, so that it is not necessary to perform feeding for discharge between electrodes. Therefore, a feeding member does not need to be connected to the metal structure from the outside of a bulb. In addition, in the light-emitting sealed body, the metal structure is disposed in an internal space S of the bulb and a positioning unit of the metal structure is disposed only in the bulb. Therefore, in the light-emitting sealed body, the metal structure and the positioning unit do not penetrate the bulb and are not buried in the bulb and weakened portions are not formed in the bulb made of glass. Therefore, a sealing state of the bulb can be maintained surely.

The present technology provides a high-pressure sodium lamp lighting device that reduces occurrence of the acoustic resonance phenomenon. A high-pressure sodium lamp lighting device of one aspect of the present invention comprises a high-pressure sodium lamp of arc length AL within the scope of 142.8 mmAL167 mm. The lighting device also includes an electronic ballast configured to supply a high frequency AC voltage to the high-pressure sodium lamp. A lighting frequency of the electronic ballast is a frequency that avoids a first and a second acoustic resonance occurrence bands f1 kHz and f2 kHz determined based on equations from an arc tube inner diameter D mm of the high-pressure sodium lamp. The equation for f1 is a range of f1min to f1max=(7.4D+130) to (8.3D+156). The equation for f2 is a range of f2 min to f2max=(11.5D+200) to (10.0D+197).

The present technology provides a high-pressure sodium lamp lighting device that reduces occurrence of the acoustic resonance phenomenon. A high-pressure sodium lamp lighting device of one aspect of the present invention comprises a high-pressure sodium lamp of arc length AL within the scope of 142.8 mmAL167 mm. The lighting device also includes an electronic ballast configured to supply a high frequency AC voltage to the high-pressure sodium lamp. A lighting frequency of the electronic ballast is a frequency that avoids a first and a second acoustic resonance occurrence bands f1 kHz and f2 kHz determined based on equations from an arc tube inner diameter D mm of the high-pressure sodium lamp. The equation for f1 is a range of f1min to f1max=(7.4D+130) to (8.3D+156). The equation for f2 is a range of f2 min to f2max=(11.5D+200) to (10.0D+197).

The disclosure relates to a discharge lamp including a light emitting tube having a discharge space therein, and a pair of electrodes disposed in the discharge space so as to be opposed to each other, wherein a changing rate of a cross-sectional area is equal to or lower than 200%. The changing rate is a rate of change of the cross-sectional area in every 0.25 mm in a direction along an optical axis of the light emitting tube. The cross-sectional area is an area of a plane perpendicular to the optical axis in a space between an outside shape of at least one of the pair of electrodes and an inside wall of the light emitting tube.

A lamp comprising an envelope (1) of quartz glass surrounding the light source of the lamp is described, wherein an electric conductor (8), for example, an electrode rod, is at least partly embedded in the quartz glass material of the envelope (1). At the conductor (8) is provided with protrusions (15) forming a brush-like structure at this surface. The protrusions (15) preferably have an average length of between 10 m and 35 m.

The present invention relates to a high-intensity discharge lamp (1) comprising a discharge vessel (2) enclosing a filling in a discharge chamber (3), and a pair of electrode rods (4, 5) being formed of a material which is free of thorium and protruding from opposite sides into the discharge chamber (3). The diameter ED of the electrode rods (4, 5) in the discharge chamber (3) N satisfies the formula (I), wherein W represents the value of the nominal lamp power in mW and Ed represents the value of the distance of the electrode rods (4, 5) in the discharge chamber (3) in mm, and wherein the nominal lamp power W is between 20 W and 50 W. With the above formula, high-intensity discharge lamps can be easily designed with different nominal powers and/or 10 electrode distances without time consuming experiments in order to achieve an optimum performance.

[00001]$\begin{array}{cc}\mathrm{ED}{\mathrm{ED}}_0=\sqrt{.Math..Math.W/\left[1+\frac{\mathrm{Ed}-3}{3.Math..Math.\mathrm{Ed}}\right]}.Math.m-10.Math.m,& \left(I\right)\end{array}$

The preferred embodiments are directed to discloses a metal halide high-pressure discharge lamp comprising a burner which is enclosed by an outer bulb. In the outer bulb samarium is provided.

A light source, with electrodes of alternating polarity attached to a substrate in an excimer ultraviolet (UV) lamp, for generating a plasma discharge between each of the electrodes. The shape of the substrate can shape and control the plasma discharge to reduce exposure of materials susceptible to attack by the halogens. The electrodes can be located such that the plasma discharge occurs in a region where it produces less contact of the halogens with the vulnerable areas of the lamp enclosure. The materials, such as the electrodes, substrate, and envelope, can be selected to withstand corrosive materials. In another embodiment, a plurality of sealed tubes, at least some of which contain an excimer gas are positioned between two electrodes.