Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01K—ELECTRIC INCANDESCENT LAMPS
  • H01K3/00—Apparatus or processes adapted to the manufacture, installing, removal, or maintenance of incandescent lamps or parts thereof
  • H01K3/22—Exhausting, degassing, filling, or cleaning vessels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/16—Removal of by-products, e.g. particles or vapours produced during treatment of a workpiece

Definitions

• the invention relates to a method for improving a vacuum in a gas-tight container, in particular in a glass bulb, in which there are functional parts which are provided with leads led through the container wall, in which the functional parts are heated up during evacuation and, as a result, substances that escape from the functional parts and contaminate the vacuum are also extracted.
• a method of the type mentioned at the outset is known for the formation of argon laser tubes, the hot cathode of which forms the functional parts during evacuation Power supply is heated.
• contamination of the cathode or water or gas constituents is supplied to the gas stream to be extracted and is removed from the container from the latter.
• the electrical heating of the hot cathode takes place in a manner that is precisely matched to the pumping or cleaning process.
• the current is fed into the hot cathode via its external leads, which have to be connected to a power source.
• External heating during the manufacturing process involves great effort and high demands on the manufacturing process. For each part to be manufactured, contact must be made in the same way with the electrical leads so that the same electrical heating energy is used for all products. The effort required for this contacting and heating is in many cases considerable and economically unacceptable, especially since it has to be done during the evacuation.
• the invention has for its object to improve a method of the type mentioned so that it is suitable for mass production, so simple and inexpensive, the vacuum of the container and the energy supply of the functional parts to be heated is improved in each case.
• This object is achieved in that the functional parts are heated with laser radiation during the evacuation.
• the laser radiation has the advantage that for the heating of the functional parts, no feed lines through the container wall have to be connected to a power source. Rather, the heating takes place with the exclusion of mechanical components for the energy transfer which takes place from the outside into the container. It is also important that the heating process can be carried out largely independently of the spatial design of the container and the functional parts. Certain functional parts with z. B. larger mass can also be heated longer or brought to a higher temperature. The cleaning process of these functional parts can thus be accelerated or driven further than is possible when heating via the supply lines.
• incandescent lamps are particularly advantageous.
• simply heating the filament of the incandescent lamp by means of laser radiation during evacuation it is achieved that the vacuum has a considerably improved quality, so that the incandescent lamps have a longer service life and better efficiency.
• a method for influencing a vacuum in a gas-tight container in which there are functional parts during evacuation, which emit vacuum-contaminating substances that are also sucked off, surfaces of the functional parts, workpieces and / or the container adjacent to the container interior become one subjected to photoablative and / or thermal treatment with laser radiation.
• photoablative treatment has the effect that in particular particles sitting on the surfaces are removed, namely the soiling located there. These receive an energy supply from the laser radiation, which removes the binding forces to the surfaces, so that the particles are supplied to the extracted gas stream.
• the thermal treatment causes the impurities to evaporate.
• the duration of the thermal and / or photoablative treatment depends on the degree of reflection of the laser radiation. If this reaches a certain level, which is dependent on the material of the irradiated surface, the desired degree of cleaning is achieved.
• the inside walls of the container, the functional parts and / or the workpieces are irradiated with laser radiation directly and / or by reflection, so that they too can be cleaned with simple means to improve the vacuum. It is advantageous, namely simply, that laser radiation can be used both for cleaning the functional parts, the workpieces and also for cleaning the inside walls of the container.
• a device for improving a vacuum in a gas-tight container in which there are functional parts or workpieces during the evacuation, and which is connected to a suction guide, has the characteristic features that the container transmits at least one laser radiation from a laser arranged outside the container Wall section is provided.
• the wall section which transmits laser radiation consists of a material which absorbs little radiation energy, which is thus designed as a window inserted into the container or forms the container as a whole.
• the laser radiation has a wavelength in the container wall or its wall section which causes low absorption losses and / or has a low intensity in the region of the transmitting wall section. Both properties of the device cause as much radiation energy as possible to get to where it is to be used for heating and / or photoablative treatment.
• the container is designed as a glass bulb of an incandescent lamp and a functional part as its filament.
• neodymium or similar solid-state or argon ion lasers for heating and / or excimer gas lasers for ablation treatment. These lasers are particularly suitable for the stated purposes, which does not exclude that other lasers are used.
• Fig. 1 is a schematic representation of an incandescent lamp, which is evacuated and treated with laser radiation, and
• Fig. 2 is a schematic representation of a further device according to the invention. Best ways to carry out the invention
• the incandescent lamp 10 has a container 11 in the form of a glass bulb with a base 12 and a filament support 13 which has feed lines 14 for a filament which forms a functional part 15 and is held by a supporting frame 16 of the filament support 13.
• the attachment of the filament support 13 in the base 12 of the incandescent lamp 10 is conventional and therefore not shown.
• the base 12 of the incandescent lamp 10 is pushed over with an intake socket 17 which has an elastic sealing ring 18 which comes into contact with the base 12.
• a pump not shown, is connected to the suction nozzle 17 and evacuates the interior 19 of the incandescent lamp 10 by suctioning off a gas stream in the direction of the arrow 20.
• a laser radiation 21 is applied, which is focused on the functional part 15.
• laser radiation with a wavelength of 1.06 ⁇ m from a neodymium laser is used.
• This laser radiation penetrates the glass container 11 or lamp bulb with low radiation losses, which are negligible.
• the laser radiation is largely absorbed by the functional part 15.
• the removal of these substances during evacuation prevents the vacuum in the interior 19 from deteriorating during subsequent operation of the incandescent lamp, and thus the life and efficiency of the incandescent lamp 10 are reduced.
• FIG. 2 shows a container 11 as a treatment chamber, in which a workpiece 22 is arranged and the interior 19 of which is connected to a vacuum pump 24 by means of a suction line 23.
• a laser 25 is used to irradiate the workpiece 22, the radiation 26 thereof is directed onto the workpiece 22 using a focusing device 27, the focused radiation 21 penetrating a wall section 29 of the wall 30 of the container 11.
• This wall section 29 is made of a material that absorbs little radiation energy, so that most of the radiation energy of the radiation 21 is available for treating the workpiece 22.
• the laser radiation can be selected such that it has a wavelength which causes low absorption losses in the wall section 29. It is also possible to influence the laser radiation in such a way that it has a low intensity in the area of the wall section 29 due to the corresponding spatial extension.
• the laser radiation 21 is emitted onto the workpiece 22 essentially horizontally into the container interior 19.
• the lines 32 represent further possible center lines of the laser radiation
• the laser radiation 21 irradiates the inner walls 31 directly or by reflection from an inner wall or with a distribution body on another inner wall and / or on rear sections of the workpiece 22 or a functional part. This enables the container 30 to be heated, or a photoablative treatment which is interrupted, for example, if the measured reflectance shows that the walls or parts are clean.
• the workpiece 22 or a functional part can always be treated in a device according to the invention with a method according to the invention if its material allows sufficient absorption of the laser radiation. Tungsten and steel functional parts that have very widespread applications are preferred.

Landscapes

• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Plasma & Fusion (AREA)
• Mechanical Engineering (AREA)
• Cleaning In General (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)
• Laser Beam Processing (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6319270

Family Applications (1)

Country Status (3)

Cited By (1)

Citations (2)

Family Cites Families (3)

• 1987
  • 1987-01-22 DE DE19873701724 patent/DE3701724A1/de active Granted
• 1988
  • 1988-01-21 EP EP19880901016 patent/EP0341257A1/de not_active Withdrawn
  • 1988-01-21 WO PCT/DE1988/000029 patent/WO1988005599A1/de not_active Application Discontinuation

Patent Citations (2)

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