Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/30—Vessels; Containers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J61/00—Gas-discharge or vapour-discharge lamps
  • H01J61/02—Details
  • H01J61/30—Vessels; Containers
  • H01J61/305—Flat vessels or containers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J65/00—Lamps without any electrode inside the vessel; Lamps with at least one main electrode outside the vessel
  • H01J65/04—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels
  • H01J65/042—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels by an external electromagnetic field
  • H01J65/046—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels by an external electromagnetic field the field being produced by using capacitive means around the vessel

Definitions

• the invention is based on a discharge lamp according to the preamble of claim 1.
• discharge lamp here encompasses sources of electromagnetic radiation based on gas discharges.
• the spectrum of the radiation can encompass both the visible range and the UV (ultraviolet) / VUV (vacuum ultraviolet) range and the IR (infrared) range.
• a phosphor layer can also be provided for converting invisible radiation into visible radiation.
• dielectrically disabled electrodes are typically realized in the form of thin metallic strips which are arranged on the outer and / or inner wall of the discharge vessel. If all electrodes are arranged on the inner wall, at least some of the electrodes must be completely covered with a dielectric layer in relation to the inside of the discharge vessel.
• Discharge lamps of this type are usually referred to as dielectrically disabled discharge lamps or dielectric barrier discharge lamps, sometimes also as silent discharge lamps and are known, for example, from EP 0363 832 (FIG. 3) and WO 98/43279 (FIGS. 3a, 3b). More precisely, the invention relates to the above-mentioned lamp type with a large-area discharge vessel, in particular so-called flat lamps. Such lamps typically have two, at least in sections and approximately flat discharge vessel walls which are adjacent to one another in parallel.
• the front or bottom plate are usually connected to one another in a gastight manner via a frame and thus form the discharge vessel.
• the base plate and / or front plate can be shaped in such a way that a discharge vessel is already formed when they are joined together.
• the bottom and / or front panel can be trough-shaped, e.g. by deep drawing a flat glass plate.
• the majority of the shaped base or front plate is at least approximately flat in this case too.
• such a lamp requires one or more support points for stabilization, also referred to below as spacers.
• a discharge lamp contains a gas filling of a defined composition and filling pressure and therefore has to be evacuated before filling. Consequently, the discharge vessel must withstand both negative pressure - namely during the manufacture of the lamp - and the subsequent filling pressure, which in such lamps is usually less than atmospheric pressure, for example between 10 kPa and 20 kPa.
• the spacers must be positioned in such a way that the discharge, which takes the form of numerous fertilize burns essentially parallel to the base plate of the flat discharge vessel, is not or at most slightly influenced. For this reason, and in order to impair the luminance on the front plate of the flat discharge vessel as little as possible, the extent of the contact surface of each spacer is kept as small as possible, at least to the extent that a reliable support function of the spacers is still guaranteed.
• EP 0324 953 A1 discloses a flat radiator with dielectrically impeded electrodes and spacers (e.g. FIG. 1).
• the spacers are formed by elongated spacers made of insulating material.
• Spacers with other shapes are also known, for example columnar and spherical.
• columnar and spherical In the case of a column, different cross-sectional shapes are conceivable.
• the individual spacers are usually brought to the desired dimensions by grinding and polishing. The disadvantage here is that these spacers form relatively dark spots in the luminous front panel of the lamp.
• the or each spacer is provided with an optically diffuse surface at least in the area of a support surface.
• the entire surface of the or each spacer can be provided with a diffuse surface.
• the diffuse surface can be realized by matting, for example by etching with hydrofluoric acid, by sandblasting or the like.
• the diffuse surface can also be realized by a thin matt white color layer.
• the surface area of the support surface is as small as possible, so that it is as little recognizable as possible compared to the expansion of the front panel.
• the contact area should not be minimized in such a way that in extreme cases it can be regarded as a quasi-punctiform, since this could increase the local load on the discharge vessel plates inadmissibly.
• contact surfaces have proven themselves that nevertheless support a relatively large area with a small surface area, for example cruciform contact surfaces.
• the cross arms are preferably designed to be relatively narrow compared to a rectangle, which can be viewed as spanned by the cross.
• each spacer is formed by a body which has a thickening between the two contact surfaces, for example a polished ball. It has been shown that, in this case, each contact surface is depicted as a dark "point" on the front plate of the lamp during lamp operation. A dark yard appears around this "point”. The cause seems to be the shadow cast by the ball against the inner wall of the front panel.
• the contact surface of the ball is matted.
• the upper hemisphere of the sphere ie the hemisphere that Ren pole is within the contact surface of the ball with the inner wall of the front panel, additionally coated with fluorescent.
• the support surface itself is spared by the phosphor or the phosphor layer is at least thinner on the support surface.
• the fluorescent layer on the "upper" hemisphere of the sphere reflects or scatters light into the area shaded by the sphere and consequently avoids the dark courtyard mentioned above.
• the uncoated "lower” hemisphere allows light to enter the sphere, which partly emerges from the support surface and through the front plate and thus prevents the formation of the dark "point” mentioned above on the front plate.
• the surface of the or each spacer is treated in such a way that the or each surface in question, possibly with the exception of the contact surface, has the properties of a “radiation trap”.
• microstructures in particular in the form of prisms or pyramids on the surface of the or each spacer.
• the effect of the radiation trap in this case is based on the fact that a part of the light rays reflected by a structure strikes a directly adjacent structure and is at least partially broken by this structure into the spacer in question.
• the effect of the radiation trap can also be achieved by a kind of anti-reflection interference layer, which is on the surface of the or each of the spacer is applied.
• a kind of anti-reflection interference layer which is on the surface of the or each of the spacer is applied.
• this variant is technically complex, since interference layers are typically realized by a stack of thin layers with an alternating high or low refractive index.
• the material of the spacers consists of optically transparent material, for example glass. Only then can the light beams coupled into the spacers pass through them at all, i.e. emerge from the spacers without unacceptably high losses and thereby contribute to their brightening. In this way, the spacers on the front panel can be seen as little as possible, i.e. affect the homogeneity of the luminance distribution on the front panel as little as possible.
• 3a shows a further embodiment of a spacer in a top view
• FIG. 3b shows the spacer from FIG. 3a in a side view.
• FIG. 1 shows a schematic representation of the arrangement of spacer 1 in a typical electrode configuration of a flat radiator lamp for the backlighting of a liquid crystal screen (not shown), to which reference is further made to document W098 / 43276 3 and 4 cathodes arranged.
• the cathodes 4 have nose-like projections 5 (cf. YJO 98/11596), on each of which a partial discharge is formed during operation.
• each anode 3 is completely covered with a dielectric layer (not shown).
• a frame 6 of the discharge vessel is indicated, which connects the base plate 2 to a front plate (not shown) in a gas-tight manner and thus forms a discharge vessel.
• the light from the flat lamp is essentially coupled out through the front panel.
• Figure 2 illustrates the spacers 1 in a detail and cross-sectional view of Figure 1.
• the same features are provided with the same reference numerals.
• the spacer 1 - a precision glass ball made of soft glass with a diameter of 5 mm - lies between the base plate 2 and the front plate 7 of the flat lamp.
• the entire surface 8 of the ball 1 is etched matt using hydrofluoric acid.
• the glass ball 1 is soldered to the base plate 2 via a glass solder 9 in order to fix it during assembly.
• the glass solder 9 is preferably mixed with a white pigment, for example with about 1 to 10 percent by weight (% by weight) of rutile (TiO 2 ), in order to prevent the glass ball 1 from projecting a possibly dark color of the glass solder 9 to the front plate 7.
• the glass ball 1 only bears against the front plate 7.
• the "upper" hemisphere of the glass ball 1 adjacent to the front plate 7 is - with the exception of a small area 110 around the support surface of the ball 1 on the front plate 7 - coated with a phosphor layer 10, which is also on the base plate 2 and on the front plate 7 located.
• a prism film 11 (brightness enhancement film from the manufacturer 3M).
• FIGS. 3a, 3b schematically show a further exemplary embodiment of a spacer 13 in a top view and in a side view. It is a glass column with a star-shaped cross section, the star having four arms 14a-14d. The upper end face of the glass column 13 is provided with a matt white color layer 15.
• glass columns with a cross-shaped cross section have also proven themselves (not shown), in particular those with cross arms that are narrow in comparison to the spanned area.
• each glass ball 1 is replaced by such a glass column 13.
• the upper end face or the color layer 15 forms the contact surface with the front plate 7 of the discharge vessel of the lamp.
• the advantageous effect of the invention is not limited to the shapes of the spacers listed in the exemplary embodiments.

Landscapes

• Vessels And Coating Films For Discharge Lamps (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=7906196

Family Applications (1)

Country Status (10)

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Family Cites Families (10)

• 1999
  • 1999-04-28 DE DE19919363A patent/DE19919363A1/de not_active Withdrawn
• 2000
  • 2000-04-19 KR KR1020007014907A patent/KR20010053242A/ko not_active Application Discontinuation
  • 2000-04-19 US US09/719,986 patent/US6879108B1/en not_active Expired - Lifetime
  • 2000-04-19 EP EP00943530A patent/EP1092232A1/de not_active Withdrawn
  • 2000-04-19 JP JP2000614485A patent/JP2002543562A/ja active Pending
  • 2000-04-19 CN CNB008007160A patent/CN1253919C/zh not_active Expired - Fee Related
  • 2000-04-19 CA CA002336032A patent/CA2336032A1/en not_active Abandoned
  • 2000-04-19 WO PCT/DE2000/001227 patent/WO2000065635A1/de not_active Application Discontinuation
  • 2000-04-19 HU HU0102721A patent/HUP0102721A3/hu unknown
  • 2000-04-21 TW TW089107563A patent/TW484166B/zh not_active IP Right Cessation

Non-Patent Citations (1)

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