Abstract: Various configurations of a projection system, of a lithographic apparatus, and of a device manufacturing method are disclosed. According to a disclosed configuration, the projection system is configured to project a patterned radiation beam onto a target portion of a substrate. The projection system includes an optical element having a first face and a second face. The first face is configured to be exposed to an external gaseous environment connected to the outside of the lithographic apparatus. The second face is configured to be exposed to an internal gaseous environment, the internal gaseous environment being substantially isolated from the external gaseous environment. The projection system further includes a pressure compensation system configured to adjust the pressure in the internal gaseous environment in response to a change in pressure in the external gaseous environment or a pressure differential between the internal gaseous environment or the external gaseous environment.

Abstract: The invention relates to a backlight module for backlighting an LCD-display unit, comprising holding means for holding a number of substantially longitudinal fluorescent lamps, wherein each of the lamps comprises a glass envelope, supply means for energizing said lamps, and cooling means for removing at least part of the heat developed by the lamps, wherein the cooling means comprise at least a first metal heat-conducting body which is thermally coupled to the glass envelope of at least one the lamps, and wherein the cooling means are in contact with only a limited surface area of the glass envelope of said at least one lamp. The provision of a heat-conducting body renders it possible to relocate the control mechanism further away, so that a screening of the light-emitting surface of the lamp is reduced. This holds good for any possible control equipment and for other voluminous parts of the heat-conducting systems.

Abstract: A lithographic apparatus is disclosed. The apparatus includes an illumination system to provide a beam of radiation, and a support structure for supporting a patterning device. The patterning device serves to impart the beam with a pattern in its cross-section. The apparatus also includes a gas flushing device for flushing a substantially laminar flow of gas across the beam of radiation and/or along a surface of an optical component. The gas flushing device includes a single gas outlet that has an inner rim at a downstream end of the gas outlet. The inner rim defines a total gas outlet area. The gas outlet is provided with a laminator that has an effective area out of which, in use, the substantially laminar flow of gas flows. The laminator effective area includes material that has laminator openings and is at least as large as the total gas outlet area.