DE3304857A1 - Low-pressure gas-discharge lamp, especially a low-power fluorescent lamp - Google Patents

Description

Low-pressure gas discharge lamp, in particular fluorescent lamp small performance

The invention relates to a low-pressure gas discharge lamp capped on one side in compact form.

Fluorescent lamps with parallel arranged rod-shaped Pipe parts that pass through with an elbow part or another Connection are connected to each other are described in DE-PS 858 105, DE-OS 30 11 382 and DE-OS 30 11 383. The aim of all three inventions was to create a cooling zone to stabilize the mercury partial pressure in the lamp. This was achieved in that the ends of each rod-shaped pipe part above the connection point are not included in the gas discharge. The disadvantage of such a geometric structure is that that these pipe parts, which act as cooling zones, contribute only slightly to the generation of light. Another disadvantage is.

that the surface of the cooling zone must remain relatively small in order to have the largest possible surface for the emission of light obtain·

This means that the lamp is operated with a high thermal load only possible with a sharp decrease in the light yield · The invention is based on the object of the discharge vessel geometrically designed so that a cooling zone with a large surface is created, which is not for reduction the light-emitting surface of the discharge vessel leads

According to the invention this is achieved in that the distance between the electrodes and the vessel ends is 2.0 to 4 »O times the Inside diameter of 6 to 16 mm of the rod-shaped parallel tube parts of the discharge vessel and this The vessel part from the vessel ends to the electrodes, however, is at least twice the inner diameter of the rod-shaped parallel tube parts of the discharge vessel, is surrounded by a heat-dissipating sheath · This becomes z · B, a Mercury partial vapor pressure of (1 - 2) Pa adjusted, the ζ · Β · is optimal for pipe inside diameters of (8 - 12) mm This solution is particularly advantageous with capped lamps, where the lower ends have to be held in a stable manner and these do not contribute to the generation of light. With the invention it becomes possible to reduce the metal partial vapor pressure or · partial mercury vapor pressure in low-pressure discharge vessels with inside diameters (6έ d; - 16) mm so too regulate that the critical mercury vapor pressure for an optimal conversion of supplied electrical power into metal or mercury resonance radiation is not exceeded or is only exceeded to an insignificant extent and that no additional measures are taken such as amalgam formation for metal or mercury vapor pressure regulation are necessary

The invention is to be explained in more detail using an exemplary embodiment.

1 shows a fluorescent lamp with two rod-shaped tube parts 6 and 7 assigned in parallel, the inner surfaces of which are coated with fluorescent substance 8 · At the ends of the two tubes 6 and 7 opposite the electrodes, these are connected with a connection allowing the discharge to pass through
At the other end of the rod-shaped pipe parts 6 and 7 are located

LO are the electrodes 1 and 2, the distance from the vessel ends 3 and 4 is 2.0 to 4.0 times the inner diameter of the rod-shaped Pipe parts 6 and 7 is.

The vessel parts aer rod-shaped pipe parts 6 and 7 from the vessel ends 3 and 4 up to 3 times the inner diameter are in

L5 this embodiment example of a metal sleeve 9 (aluminum) enveloped.

The heat dissipation from the outer walls and the rod-shaped tube parts 6 and 7 takes place through direct contact with the metal sleeve 9 and additionally through a heat-dissipating mixture 10 of 20 % silicone rubber and 80 % aluminum powder.

List of reference numbers

1st electrode

2nd electrode

3. End of the vessel 4. End of the vessel

5. Heat dissipating envelope

6. Rod-shaped pipe part

7. Rod-shaped pipe part

8. Phosphor layer 9 ″ metal sleeve

10 «Thermally conductive mixture

Claims (1)

Claims Low-pressure mercury vapor discharge lamp, which consists of two or more rod-shaped tubular parts arranged in parallel, which are connected to one another either with an arched part or another connection allowing the discharge to pass through, characterized in that the distance between the electrodes (1, 2) and the vessel ends (3, 4) 2.0 to 4 times the inner diameter of the rod-shaped parts and that the discharge vessel part from the vessel ends (3, 4) to the electrodes (1, 2), but at least from the vessel ends (3, 4) to twice the inner diameter of the rod-shaped Pipe parts (6, 7) in the direction of the electrodes (1, 2) are surrounded by a heat-dissipating sheath 2 · Low-pressure discharge lamp according to Claim 1, characterized in that the heat-dissipating envelope is a mixture is made of a binder or adhesive and a thermally conductive filler. 3. Low-pressure discharge lamp according to Claims 1 and 2, characterized in that the mixture consists of a part of silicone rubber and on the other hand consists of aluminum powder or shavings 4. Low-pressure discharge lamp according to claim 1 to 3, characterized in that the mixture 10 - 50 % binding or adhesive material and Contains 50-90% heat-dissipating filler material. 5. Low pressure discharge lamp according to claim 1, characterized in that the heat-dissipating sheath is a metal sleeve that is in direct contact with the surface of the Has discharge vessel. 6. Low-pressure discharge lamp according to claim 1 to 5, characterized in that the heat-dissipating envelope consists of a metal sleeve in conjunction with a mixture of a binding or adhesive material and a heat-dissipating filler. 7. Low-pressure discharge lamp according to claim I _1, characterized in that the distance between the electrodes (1, 2) from the vessel ends (3, 4) is preferably 3 times the inner diameter of the rod-shaped tubular parts (6, 7) of the discharge vessel and the electrodes (1, 2) are a double helix or a triple helix with a tungsten core in the primary helix.