Abstract: A housing for an elongate electrodeless bulb which is energiseable by an rf field such as a microwave field, preferably at or around 2.45 GHz. The housing is constructed of electrically conductive material and is arranged to have a substantially unobstructed opening through which the bulb is visible from outside the housing, and the housing is arranged to hold the bulb in a position which is recessed into the housing such that in use, the bulb is energized by virtue of its position within the housing and adjacent surrounding conductive parts of the housing substantially attenuate the rf field near the opening so that the rf field strength outside the housing is substantially zero whereby visible light or UV light is freely allowed out through the opening.

Abstract: An apparatus having one or more UV bulbs arranged around a structural element and within an outer conductive element. The apparatus also contains an inner conductive element which extends the length of the apparatus. The inner and outer conductive elements are coupled to a microwave source to enable the UV bulbs to be powered.

Abstract: This invention relates to apparatus for maximising ozone generation from a UV bulb. The apparatus includes a UV bulb which emits UV light below 200 nm, peaking at 185 nm. Bulbs emitting UV light at 185 nm are well known to generate ozone but generally also emit UV light at 254 nm which is well known to deplete ozone. The concept of the present invention is to create an environment where air or oxygen carrying gas can be exposed to the 185 nm and 254 nm UV light outputs from a bulb in such a way that the 185 nm ozone generating effect is enhanced and 254 nm ozone depleting effect is reduced. The apparatus also includes a member which may either be transmissive to or non-transmissive to UV light at 254 nm and the environment in which the effect of the UV light at 185 nm is enhanced exists between the UV lamp and the member.

Abstract: Sterilisation of airflow in a duct may be achieved by irradiating the air with light in the ultraviolet spectrum. Electrodeless bulbs may be enclosed in part of a duct and fed with RF energy in order to energize the bulb. The RF energy may be contained using grids dimensioned to be opaque to the selected RF wavelength.

Abstract: An ultraviolet generator powered by a microwave source, such as a magnetron, is disclosed. The generator has an elongated inner element, preferably an electric conductor in the form of a polished metallic rod or an electrodeless bulb. An outer conductor, formed from an electrically conductive mesh or a perforated conductive material, is arranged around the inner element. One or more electrodeless ultraviolet bulbs are arranged, preferably radially, around the inner element within the outer conductor. The inner element and outer conductor are arranged for direct coupling to the microwave power source using a waveguide. The inner element is joined to the outer conductor by a disk positioned at the end of the generator opposite to the power source.

Abstract: A housing for an elongate electrodeless bulb which is energiseable by an rf field such as a microwave field, preferably at or around 2.45 GHz. The housing is constructed of electrically conductive material and is arranged to have a substantially unobstructed opening through which the bulb is visible from outside the housing, and the housing is arranged to hold the bulb in a position which is recessed into the housing such that in use, the bulb is energized by virtue of its position within the housing and adjacent surrounding conductive parts of the housing substantially attenuate the rf field near the opening so that the rf field strength outside the housing is substantially zero whereby visible light or UV light is freely allowed out through the opening.

Abstract: An apparatus having one or more UV bulbs arranged around a structural element and within an outer conductive element. The apparatus also contains an inner conductive element which extends the length of the apparatus. The inner and outer conductive elements are coupled to a microwave source to enable the UV bulbs to be powered.

Abstract: The light system has a plurality of bulbs configured to emit light when energised by microwaves, an outer conductive element which is at least partially transmissive to UV light; and an inner conductor situated within the outer conductive element. The inner conductor of the light system coupled directly to a microwave source. Additionally, the inner conductor is provided with a plurality of projections, each projection contacts one of the bulbs to promote even distribution of the microwave energy.

Abstract: Sterilisation of airflow in a duct may be achieved by irradiating the air with light in the ultraviolet spectrum. Electrodeless bulbs may be enclosed in part of a duct and fed with RF energy in order to energize the bulb. The RF energy may be contained using grids dimensioned to be opaque to the selected RF wavelength.

Abstract: An ultraviolet generator powered by a microwave source, such as a magnetron, is disclosed. The generator has an elongated inner element, preferably an electric conductor in the form of a polished metallic rod or an electrodeless bulb. An outer conductor, formed from an electrically conductive mesh or a perforated conductive material, is arranged around the inner element. One or more electrodeless ultraviolet bulbs are arranged, preferably radially, around the inner element within the outer conductor. The inner element and outer conductor are arranged for direct coupling to the microwave power source using a waveguide. The inner element is joined to the outer conductor by a disk positioned at the end of the generator opposite to the power source.

Abstract: It is desirable to be able to provide evenly illuminated, long lasting, relatively high power ultraviolet radiation for manufacturing processes such as sterilization and ink or adhesive curing. A generally rigid waveguide (2) having a slot (8) formed in one of its short sides (4) (or optionally one of its long sides (6)) may have an ultraviolet energizable elongate lamp (10) inserted therein. When the waveguide is coupled to a source of microwave energy, the slot radiates and the radiated energy is coupled almost exclusively into the lamp (10). With suitable choices of slot widths this provides even illumination with minimal microwave leakage.

Abstract: In microwave energized ultraviolet bulbs, much of the input energy is converted to heat emissions. It has been found that the efficiency of such a bulb can be optimized by monitoring power density of different portions of the UV spectrum (for example, UVA and UVC) and adjusting input power to the bulb and/or the bulbs temperature accordingly. This may be used not only to improve efficiency of the bulb but also to improve the efficiency of emissions at either UVA or UVC. A control system and suitable control parameters are described.

Abstract: A sterilizer comprising an openable enclosure (2,4) for surrounding one or more articles (8A, 8B) to be sterilized, the enclosure being arranged to attenuate microwave radiation such that in use, when the enclosure is irradiated with microwave energy, the microwave field energy throughout the interior of the enclosure is significantly less than that outside the enclosure, and the enclosure including a gas tight cavity (2C, 4C) containing a gaseous charge, the charge being chosen from the group of materials which emit ultraviolet radiation when irradiated with microwave radiation.

Abstract: Apparatus for radiating energy at one or more predetermined wavelength comprising: a housing (4), a source of microwave energy coupled to and located outside the housing and a window forming part of the wall of the housing, the window being formed from a material which is substantially transparent to radiation at the or each predetermined wavelength and at the wavelength of the microwave source, the window including gas of a predetermined composition at a predetermined pressure contained in a gas-tight enclosure (2) defined by the window material, the gas composition being chosen to emit energy at the or each predetermined wavelength in response to microwave energy from the housing (4) impinging generally on an inner surface of the window, the window being arranged substantially to be opaque at the wavelength of the microwave energy and being arranged to provide an unobstructed radiating path from its outer surface for the energy of the or each predetermined wavelength.