Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J5/00—Details relating to vessels or to leading-in conductors common to two or more basic types of discharge tubes or lamps
  • H01J5/32—Seals for leading-in conductors
  • H01J5/34—Seals for leading-in conductors for an individual conductor
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J5/00—Details relating to vessels or to leading-in conductors common to two or more basic types of discharge tubes or lamps
  • H01J5/46—Leading-in conductors
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/04—Electrodes; Screens; Shields
  • H01J61/06—Main electrodes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/04—Electrodes; Screens; Shields
  • H01J61/06—Main electrodes
  • H01J61/09—Hollow cathodes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/36—Seals between parts of vessels; Seals for leading-in conductors; Leading-in conductors
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/70—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr
  • H01J61/76—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr having a filling of permanent gas or gases only
  • H01J61/78—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr having a filling of permanent gas or gases only with cold cathode; with cathode heated only by discharge, e.g. high-tension lamp for advertising
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
  • H01J9/02—Manufacture of electrodes or electrode systems

Definitions

• the invention relates to a cold cathode fluorescent lamp which essentially comprises a discharge vessel coated on the inside with a phosphor which contains a filling component which emits UV light, two or more hollow cathodes made of one material of the group Mo, W, Nb, Ta and their alloys and two or more current feed-through pins made of a material of the group Mo, W and their alloys.
• Cold cathode fluorescent lamps are used as backlighting for liquid crystal displays.
• a low-pressure mercury discharge generates UV radiation, which is converted into visible light by a phosphor layer applied to the inside of the discharge vessel.
• the discharge vessel is usually made of hard glass, such as borosilicate glass, and is usually tubular.
• electrodes which have different shapes depending on the lamp type.
• emission-promoting substances containing, for example, Ba, Sr, rare earth metals or yttrium
• the contacting of the electrodes is carried out by current feedthrough pins. These are connected in a vacuum-tight manner to the discharge vessel by means of a squeezing or melting process.
• the current feedthrough pin is provided with a glass bead, which is produced by the melting of a glass ring. This process is called glazing. Subsequently, the glass bead is connected to the discharge vessel by a crimping or melting process.
• a material for the current feedthrough Fe-Ni-Co (Kovar) materials molybdenum, tungsten with low, adapted to the glass thermal expansion coefficient is used. With the miniaturization of the liquid crystal screens is also a
• Object of the subject invention is therefore to provide a cold cathode fluorescent lamp having both hollow cathodes and current feedthrough pins with high sputter resistance, the joining of the hollow cathode and current feedthrough is inexpensive and reliable feasible.
• the object is solved by the characterizing part of claim 1.
• the current feedthrough pin is a ring, a ring segment, a
• the ring, the ring segment, the hollow cylinder or the hollow cylinder segment is preferably made of a material having a significantly lower melting point compared to the hollow cathode, such as Ni, Fe, Co and their alloys.
• the ring, the ring segment, the hollow cylinder or the Hollow cylinder segment has an inner diameter which is slightly larger than the diameter of the current feedthrough pin.
• the height of the hollow cylinder or the hollow cylinder segment moves advantageously from 0.5x to 4x diameter of the hollow cylinder.
• a ring or hollow cylinder segment (slotted ring, slotted hollow cylinder) is advantageous due to lower production costs.
• the ring segment is made by bending a piece of wire, the hollow cylinder segment by embossing a band section.
• the resulting slot is preferably smaller than VA of the ring or hollow cylinder circumference.
• the ring, the ring segment, the hollow cylinder or the hollow cylinder segment is advantageously connected in a first process step with the current feedthrough pin.
• the ring, the ring segment, the hollow cylinder or the hollow cylinder segment is threaded onto one end of the current feedthrough pin and thereby positioned in a simple manner.
• the joining with the current feedthrough pin can be point or area, take place at one or more locations.
• the heat input can be done for example by means of laser or resistance welding.
• the areas of the ring or the hollow cylinder, where local heat input takes place can melt.
• the component produced by the first joining step is connected to the hollow cathode in a further joining step.
• the heat input is again preferably by resistance or laser welding.
• the contact surface is preferably the hollow surface of the inclined surface or the cross-sectional area of the hollow cylinder.
• the heat input preferably takes place from the radial direction, wherein the ring is selectively, partially or over the entire circumference connected to the hollow cathode.
• the heat input is so small in the case of hollow cathodes of molybdenum or tungsten that melting, preferably also a complete recrystallization and thus embrittlement of the bottom portion of the hollow cathode, can be avoided.
• An advantageous welding process is the Call laser welding, wherein the beam guide axially on the
• Hollow cathode bottom is directed. Although it is thus unavoidable to avoid a local embrittlement of the hollow cathode bottom, which, however, since there is a cohesive connection between the hollow cathode and the current feedthrough pin via the ring or hollow cylinder, does not lead to a reduction in the service life. Cold cathode fluorescent lamps with the components according to the invention therefore show no reduction in the service life even when shaken.
• the current feedthrough pin is connected to a power supply pin. While the current feedthrough pin the requirement for similarity of the expansion coefficient pin / glass material selection significantly limits, this is not the case for the lamp outside power supply pin. Typically, a copper clad wire (Dumet) is used for the power supply pin. This is butt welded to the current feedthrough pin to a so-called combination lift. Processually, it is cheaper, before the connection current feedthrough pin / hollow cathode connection
• the hollow cathode can be made in one piece or in several parts.
• a multipart, preferably two-part design is usually chosen when a one-piece version, produced by deep drawing, from manufacturing technical (too large draw ratio) or cost reasons is out of the question.
• FIG. 1 shows a schematic representation of a cold cathode fluorescent lamp
• FIG. 6 Hollow cylinder according to the invention in cross section
• FIG. 7 Hollow cylinder segment according to the invention in cross section
• FIG. 1 shows the essential components of a
• Cold Cathode Fluorescent Lamp -1- namely a discharge vessel -3- coated on the inside with phosphor -2-, the hollow cathode -A-, the current feedthrough pin -5- and the current supply pin -8-.
• the current feedthrough pin -5- was welded to the hollow cathode -4-, the laser beam was directed axially to the bottom of the hollow cathode -A-.
• a component was made using a ring -6-.

Landscapes

• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Vessels And Coating Films For Discharge Lamps (AREA)
• Discharge Lamp (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=35376913

Family Applications (1)

Country Status (6)

Families Citing this family (2)

Family Cites Families (9)

• 2004
  • 2004-12-15 AT AT0091504U patent/AT8028U1/de not_active IP Right Cessation
• 2005
  • 2005-12-12 WO PCT/AT2005/000498 patent/WO2006063371A2/de active Application Filing
  • 2005-12-12 KR KR1020077012211A patent/KR20070093969A/ko not_active Application Discontinuation
  • 2005-12-12 JP JP2007545778A patent/JP2008523568A/ja active Pending
  • 2005-12-12 CN CNA2005800430827A patent/CN101080803A/zh active Pending
  • 2005-12-12 EP EP05817708A patent/EP1825497A2/de not_active Withdrawn

Non-Patent Citations (1)

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