A double jacket arc lamp is disclosed. A double jacket arc lamp may be formed with an electric lamp capsule having an inner light transmissive envelope with electrical leads extending from the inner envelope through a first seal, and a second light transmissive envelope sealed to the inner envelope at a second seal to substantially surround the electric lamp capsule and form an enclosed volume between a portion of the exterior of the inner envelope and the interior of the outer envelope, and leaving the leads unenclosed by the outer envelope. The lamp leads then pass through only one seal, and have no portions exposed in the intermediate insulating volume. The intermediate volume of the double jacket arc lamp may include a fill gas including a noninert component. In particular, the fill gas may include oxygen which is thought to have useful gettering and glass preservation attributes. The use of oxygen in the fill gas allows the lamp to operate at a higher temperature, and therefore more efficiently.
A low-pressure mercury vapor-filled discharge lamp has a glass arc tube and a glass outer tube disposed coaxially with the arc tube forming a space therebetween. A gas is disposed in the space. The arc tube contains a gas and is coated with a phosphor. A first seal hermetically seals the inner tube. A second seal seals the inner tube to the outer tube. The inner tube further contains a pair of cathodes coupled to Dumet wires extending from the interior of the inner tube to the outside of the lamp structure. The pressure in the space is set at not more than 1 Pa, which is nearly high vacuum. The longer the radial dimension of the space, the greater the heat retaining capacity and the better the temperature characteristics which can be obtained. However, by setting the pressure of the space at 1 Pa or less, the optimum heat retaining capacity can be obtained while reducing the diameter of the low-pressure mercury vapor filled discharge lamp 1.
A lamp comprising an elongate light source and a coaxially transparent sleeve surrounding the light source, wherein the light source is fixed at one end in the sleeve by means of a cured cement, wherein a cement barrier is present between the light source and the sleeve for preventing the cement in its uncured state from entering the middle portion of the lamp, and wherein said cemenit barrier is made of a somewhat flexible material.
A discharge bulb including: an arc tube having a light emitting portion constructed in a manner that a light emitting substance is enclosed therein by pinch-sealing the arc tube, and discharge electrodes are oppositely arranged therein; and a shroud glass tube hermetically sealing and covering the arc tube, so as to form a space between the shroud glass tube and the arc tube. And a water content or pressure of gas enclosed in the sealed space is specified.
The invention relates to an illumination unit having an electric lamp which has a lamp vessel having a sealed-off end in the form of a glass base, and having an envelope which at least partially surrounds the lamp vessel and rests on the lamp vessel such that the glass base protrudes from the envelope.
HID lamp has a U-enhancer connected between first and second leads for an arc tube. The UV-enhancer has a quartz envelope containing an electrode connected to the first lead, and is surrounded by a metal ring which is spaced from the envelope by a sleeve of borosilicate glass. The ring is capacitively coupled to the envelope and is electrically connected to the second lead, which may also support the sleeve.
