JP2006269428A - Display with back illumination provided with light emission means having external electrode - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display with back illumination capable of satisfying a desired requirement to a high extent by avoiding drawbacks of a conventional technique. <P>SOLUTION: This display is a display with back illumination for a cellular phone, automobile, television, computer, home and camera, in particular, a flat display 1, and is provided with at least one light emission means 3 having a glass hollow body and external electrodes. This display is characterized by that a glass composition for the glass hollow body of the light emission means 3 is so selected that tanδ/ε'<5×10<SP>-4</SP>can be applied to a quotient calculated from a loss angle (tanδ) and a dielectric constant (ε'). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The invention relates to a backlit display comprising at least one light-emitting means with external electrodes, for example a fluorescent lamp, in particular an EEFL (External Electrode Fluorescent Lamp).

  Flat display devices play an increasingly important role. Usually, a self-luminous display is realized by white backlighting. This back lighting is preferably performed by a gas discharge lamp.

  With respect to backlighting in displays, there are very special demands on the glass and on the properties of the glass. For example, the light emitting means used should have very small dimensions and thus very little thickness and have UV absorbing properties. The irradiated high frequency energy should not be absorbed by the lamp glass or only slightly. The purpose is, for example, to emit light emitted from a luminescent gas confined in a fluorescent lamp. This has heretofore been premised on that the glass has a very small imaginary part of the dielectric constant, a real part of the highest possible dielectric constant and a very small dielectric loss angle tan δ. In this case, the dielectric loss angle is used as a measure of the energy absorbed by the glass and converted into lost heat in the excited dielectric alternating magnetic field.

  In the prior art, for example, a fluorescent lamp (EEFL) having an external electrode for back lighting is described in Patent Document 1 and Patent Document 2. However, in this case, it has dielectric characteristics that do not allow efficient gas discharge at all, and it has a very little dielectric breakdown resistance (meaning dielectric breakdown at high voltage) when voltage and temperature are generated. Glass having so-called pinhole burning) is used.

  Patent Document 3 and Patent Document 4 describe a container for manufacturing a fluorescent lamp having an external electrode. The glass used has a relatively low dielectric power loss with a tan δ not exceeding 0.02 at 40 kHz and 250 ° C.

Patent Document 5 and Patent Document 6 are glasses having a high dielectric constant and a relatively low dielectric tan δ, and have a high alkali content as described above, and the total consisting of Li ₂ O, Na ₂ O and K ₂ O. Disclosed is a glass that is 4.5-25% by weight. The dielectric loss for an efficient fluorescent lamp is still too high.

Therefore, it is necessary to develop a display having a highly efficient light emitting unit. Conventional fluorescent lamps (EEFL) with external electrodes use small glass tubes that have significant electrical conductivity with respect to current in the range between 10 kHz and 100 kHz, especially when operated with alternating voltage. This significantly impairs the overall efficiency of such fluorescent lamps, for example the advantages of EEFL over CCFL (Cold Cathode Fluorescent Lamp), i.e. inherently easier start-up and easier Manufacturing is largely offset by efficiency losses.
Korean Patent Publication No. 1020030080915A Korean Patent Publication No. 1020020071685A JP 2005-093422 A International Publication No. 2005 / 015606A1 JP 2002-338296 A International Publication No. 02 / 074922A1

  Accordingly, it is an object of the present invention to provide a backlit display that avoids the disadvantages of the prior art and meets the desired requirements to a high degree. In particular, it is intended for this purpose to use light emitting means having external electrodes, for example fluorescent lamps. These light emitting means can be illuminated by external guidance and require a metal wire or electrode extending through the annular lamp glass. In this case, a glass is used that has properties that can be modified and optimized so that as little as possible incident high frequency energy is absorbed. That is, the total power loss of the lamp glass of the light emitting means should be reduced to a minimum. Furthermore, it is contemplated that the glass composition has good properties of absorbing ultraviolet light.

The object of the invention is solved according to the invention by a backlit display. Back lighting is realized by light emitting means having an external electrode, to which electricity is supplied via the external electrode, in particular by a highly efficient gas discharge tube. In this case, a glass composition for the glass hollow body of at least one light emitting means having an external electrode is used, where the quotient calculated from the loss angle and the dielectric constant is tan δ / ε ′ <5 × 10 ^{− 4} , preferably <4 × 10 ⁻⁴ and <3 × 10 ⁻⁴ , very particularly preferably <2 × 10 ⁻ and <1.5 × 10 ⁻⁴ . A very particularly preferred embodiment has a quotient of tan δ / ε ′ <1 × 10 ⁻⁴ . In particular, the quotient can be adjusted to <0.7 × 10 ⁻⁴ and <0.5 × 10 ⁻⁴ .

The value of tan δ can be described by a value of 10 ⁻⁴ . At this time, from this, tan δ [10 ⁻⁴ ] / ε ′ <5 is generated for the quotient.

The value for tan δ can also be written as an absolute value. At this time, this results in tan δ / ε ′ <5 × 10 ⁻⁴ for the quotient.

As an example of the number, assuming tan δ = 0.001, ie tan δ [10 ⁻⁴ ] = 10 and ε ′ = 4,
In this case, the quotient is tan δ [10 ⁻⁴ ] /ε′=10:4=2.5, that is, tan δ / ε ′ = 0.001: 4 = 2.5 × 10 ⁻⁴ .

Accordingly, the present invention provides a _backlit display that is selected so that the glass for the glass hollow body of the light emitting means with external electrodes is kept as low as possible and thus also as efficient as possible. About. The quotient calculated from the loss angle tan δ and the dielectric constant ε ′ must not reach a predetermined upper limit. In this case, the gas discharge is emitted from the outside, and the glass functions as a dielectric in the capacitor. For a simple geometry with a planar electrode on the end face of a closed glass tube, the power loss (hereinafter referred to as P _Verlast or P _loss ) is

Where ω is the angular frequency, tan δ is the loss angle, ε ′ is the dielectric constant, d is the capacitor thickness (here, the glass thickness), A is the electrode area, l is the current intensity, and ε ₀ is Influence coefficient = 8.8542 10 ⁻¹² As / (Vm)).

Therefore, by adjusting the quotient tan δ / ε ′ within a predetermined range, it is possible to appropriately influence the glass characteristics, thereby reducing the total power loss of the light emitting means to a minimum. Surprisingly, the present invention can meet the desired requirements by using the selected glass composition as a backlight for display in a very inexpensive manner. Surprisingly, glasses that satisfy the above equation are very well suited for use in fluorescent lamps, where the quotient calculated from the loss angle and dielectric constant is 5 × 10 ⁻⁴ . It becomes clear that it is below.

In order to use light-emitting means with external electrodes, for example EEFL fluorescent lamps, for back lighting, the quotient is <5 × 10 ⁻⁴ , preferably <4.5 × 10 ⁻⁴ , particularly preferably <4. 0.0 × 10 ⁻⁴ , especially <3 × 10 ⁻⁴ , more preferably <2.5 × 10 ⁻⁴ . Good properties are achieved in the range of 0.75 × 10 ^{−4 to} 2.5 × 10 ⁻⁴ . Furthermore, it is quite particularly preferred that the quotient is <1.0 × 10 ⁻⁴ , in particular <0.75 × 10 ⁻⁴ .

  The above quotient can be appropriately adjusted, for example, in a glass composition of a glass hollow body, particularly in a silicate glass. A plurality of highly polarizable elements can be incorporated in the form of oxides into a glass matrix. By incorporating. These are, for example, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Pb, Bi, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb. And an oxide of Lu.

  In the present invention, a glass having a relatively high dielectric constant (relative dielectric constant DZ) is preferably used for the glass hollow body of the light emitting means provided in the display. In this case, the relative dielectric constant is preferably> 3 and> 4 at a temperature of 100 kHz and 25 ° C., in particular in the range of 3.5 to 4.5, more preferably> 5 and> 6, Very particularly preferably> 8. In the present invention, it is particularly preferable to use a glass having a high polarizability, that is, a dielectric constant ε ′> 5 for the glass hollow body.

  The dielectric loss coefficient tan δ is preferably 120 at the maximum, and preferably less than 100. The loss factor is particularly preferably below 80, and values below 50 and below 30 are particularly suitable. Values below 15 are particularly preferred, in particular between 1 and 15. The tan δ value may vary depending on the degree of impurities and the manufacturing method. However, it is not important to individually adjust the individual values of the loss angle tan δ and the relative dielectric constant ε ′ as low as possible, but it is important to relate the two values to each other. In fact, the quotient calculated from the two parameters is a critical quantity. Using this critical amount, the glass material characteristics can be adjusted.

It is preferable to select a glass to which tan δ / ε ′ <5 × 10 ⁻⁴ is applied to a display according to the present invention for a light emitting means having an external electrode, for example, a glass hollow body of EEFL. The frequency used is in the range of 5 to 200 kHz, preferably 10 to 150 kHz, particularly preferably 20 to 100 kHz.

  In order to adjust such a frequency, in the present invention, it is preferable to provide a light emitting means having an external electrode, particularly a means for starting EEFL with an AC voltage. However, a frequency range of 5 to 200 kHz, preferably 10 to 150 kHz, particularly preferably 20 to 100 kHz (ie outside the range of frequencies audible when exciting mechanical resonances in the system during resonance) It is preferable to use an alternating voltage of 0.5 to 10 kV, particularly preferably 0.8 to 6 kV. The means for activating the light emitting means are designed, for example, for sinusoidal signals, but rectangular signals are also preferred. This means is particularly preferably an electronic start-up unit that generates the desired voltage and signal shape. Furthermore, the electronic activation unit advantageously has a current limiter.

In another preferred embodiment, for the glass hollow body of the light emitting means, a glass with low conductivity, in particular a glass with tan δ <20 × 10 ⁻⁴ , particularly preferably tan δ <1 × 10 ⁻⁴ is used. It is very particularly preferred that the glass composition contains only a small concentration of alkali ions. In particular, the sum of Li ₂ O, Na ₂ O and K ₂ O is below 4.5% by weight, preferably significantly below 4.5% by weight.

  Furthermore, for the glass hollow body, glass whose ultraviolet ray blocking is desirably adjusted is used. For example, UV blocking within the glass can be adjusted by including rare earth ions or transition metal ions in the glass composition. For this purpose, for example, the following elements are suitable. That is, Ti, Ce, W, Nb, Bi, Yb, Fe and / or Ni.

However, the UV blocking can also be adjusted in the form of the inner or outer layer of the glass hollow body. An inner layer or an outer layer made of TiO ₂ is particularly suitable.

  Another variant according to the invention is a possible glass hollow body having a fluorescent layer made of a solid powder doped with rare earth ions and for converting ultraviolet light or blue light into totally white light. Concerning the inner layer. This solid powder is, for example, a YAG powder doped with Ce, Eu, Tm, Tb and / or Gd, for example.

  However, it is also possible to dope impurities into the glass with fluorescent rare earth ions and / or transition metal ions in order to convert ultraviolet light or blue light into totally white light. The rare earth ions are selected from, for example, Ce, Eu, Tm, Tb and / or Gd.

  As the one or more light emitting means used in the present invention having an external electrode, any light emitting means known to those skilled in the art for this purpose can be used. The light emitting means having the external electrode is preferably a discharge lamp such as a gas discharge lamp, particularly a low pressure discharge lamp. In the case of a low-pressure lamp, discrete ultraviolet light can be partially converted to visible by the fluorescent layer. Therefore, the light emitting means is a fluorescent lamp, particularly an EEFL lamp, and particularly preferably a miniaturized fluorescent lamp.

  The cross section of the light emitting means is arbitrary, and is adapted to the three-dimensional reality of the display. A round, oval, rectangular and / or planar, rectangular cross-section is preferred (eg, OSRAM's Planon®). All the light emitting means may have the same cross section or different cross sectional shapes may be combined. It is quite particularly preferred for the backlighting for the display according to the invention to be provided with one or more light-emitting means, for example EEFL, having a flat rectangular cross section with external electrodes.

  “Display” means any electronic display device in the present invention. All types of image-receiving surfaces are also applicable to the display.

  The size of the display used in the present invention is not particularly limited within the frame of the present invention. It is preferred that a display size in the range of 50 × 50 mm to 4 × 5 m is used.

  Any display known to those skilled in the art may be used in the present invention. For example, this may be a display, preferably having a structured glass plate, a liquid crystal layer, a polarizing unit and other glass plates for display.

  Usually, the display has a light distribution unit. The light distribution unit is not particularly limited within the frame of the present invention. For example, a diffuser or diffuser plate or diffuser disk or a light-guided or light-transmitting plate or disk, such as a light guide plate (LGP) can be used. However, in the present invention, the light distribution unit preferably has a polymer, glass, phase-separated glass or glass ceramic having a scattering center. It is particularly preferred that there are inhomogeneously distributed scattering centers for optimal homogeneous light distribution. Scattering centers distributed inhomogeneously in this way can be tuned, for example, by a glass ceramic crystallized in a temperature gradient.

  In another aspect, the light distribution unit has a structured or predetermined surface roughness having an rms value on the order of the wavelength of light, provided that 20 nm <rms <100.000 nm is preferred, 10 nm <Rms <10000 nm is particularly preferred. The rms value means the standard difference of the surface from the average value.

  The light distribution unit provided in the display according to the present invention may be formed as a hollow body. The wall of the hollow body guides light by reflection, and light is dispersed by the surface roughness from the hollow body (auskoppeln).

  The contact material in the glass hollow body is not particularly limited. The contact is a) a metal or thin plate made of, for example, Cu, Al, Ag, etc., b) an immersion layer made of a metal or a metal-containing conductive material, c) a conductive lacquer, eg a silver-containing conductive lacquer or d) It is selected from conductive adhesive tapes such as metal adhesive tapes.

  Furthermore, a cooling thin plate can be provided for temperature management in the light emitting means, in particular for passive cooling of the light emitting means. For active cooling, it is common to provide an aerator and / or liquid cooling.

  The structure and installation of the light emitting means and the light distribution unit are not particularly limited to the display according to the present invention. Hereinafter, a plurality of modifications according to the present invention will be described. However, the teaching according to the present invention is not limited.

  In a first variant, at least two light emitting means with external electrodes are preferably provided parallel to each other, preferably a base plate or a support plate, a cover plate or a substrate plate or a cover disc or a substrate, It is between the discs. In this case, it is appropriate that the support plate is provided with one or more depressions or hollow spaces. One or more light emitting means are stored in these depressions or hollow spaces. Preferably, each recess has one light emitting means. The emitted light of the one or more light emitting means is reflected to a display or screen.

  Advantageously, a reflective layer is applied to the reflective support plate shown in this variant, i.e. in particular in one or more depressions. This reflective layer evenly scatters the light emitted by the light emitting means in the direction of the support plate as a kind of reflector, thus causing an even illumination of the display or image receiving screen.

  As the substrate plate or cover plate or substrate disk or cover disk, any conventional plate or disk may be used for this purpose. The plate or disk functions as a light distribution unit or simply as a cover, depending on the structure and application purpose of the system. Thus, the substrate plate or cover plate or substrate disk or cover disk may be, for example, an opaque diffuser disk or a clear transparent disk.

  The device described in the first variant according to the invention is preferably used for fairly large displays, for example in the case of television receivers.

  In the second modification of the present invention, the light emitting means may be provided outside the light distribution unit, for example, according to the system according to the present invention. For example, one or more light-emitting means can be attached to the outside of the display or screen, where the light is a light-transmitting plate used as a light guide, a so-called LPG (light guide plate). ) To evenly distribute the surface of the display or screen (auskoppeln). Such an optical transmission type plate has, for example, a rough surface. This surface disperses light (auskoppeln).

  In a third variant of the inventive system, a lamp device without electrodes, ie a so-called EEFL (External Electrode Fluorescent Lamp) device may also be used. Regarding EEFL lamps, Cho G. et al., J. Phys. D: Appl. Phys. Vol. 37 (2004), 2863-2867 and Cho TS et al., Jpn. J. Appl. Phys. Vol. 41 (2002) , 7518-7521). The disclosures of these documents are fully incorporated herein.

  In a preferred embodiment of this third variant of the invention, the light emitting unit has, for example, a sealed space. This space is defined on the upper side, preferably by a structured disk, on the lower side by a support disk, and on the side by a wall. For example, light emitting means such as fluorescent lamps are on the side of the unit. This sealed space may be further divided into individual radiation spaces, for example. These radiation spaces can have, for example, a discharge luminescent material attached to the support disk with a predetermined thickness. As the cover plate or the cover disk, an opaque diffuser disk or a clear transparent disk can be used again, depending on the structure of the system.

  The backlight device according to the present invention based on this modification is, for example, a gas discharge lamp having no electrode. That is, there are no bushings and only external electrodes.

  The glass hollow body of the light emitting means having the external electrode preferably has a gas filling selected from Hg gas, noble gas, in particular Xe gas or a mixture of these gases.

  When the light emitting means used in the display according to the present invention is a high-pressure lamp, the charged gas so that a continuous spectrum is generated, or Hg gas and / or Xe gas is included as the filling gas. When it is, the Hg line spectrum and / or the Xe line spectrum become hot so that there is an additional strong shock propagation that can be triggered by the external electrode.

  The glass of the glass hollow body of the light emitting means contains or consists of a glass composition that satisfies the above-mentioned assumption of the quotient calculated from the loss angle tan δ and the relative dielectric constant ε ′. It is preferred to use one or more individual particularly miniaturized light emitting means which have a glass hollow body which substantially comprises or consists of these glasses.

In a display according to the present invention, a glass hollow glass for a light emitting means having an external electrode, for example an EEFL discharge lamp, has the following composition:
SiO ₂ 55~85 weight%
B ₂ O ₃ > 0 to 35% by weight
Al ₂ O ₃ 0 to 25% by weight
Preferably 0-20% by weight
Li ₂ O <1.0 wt%
Na ₂ O <3.0 wt%
K ₂ O <5.0% by weight, provided that
ΣLi ₂ O + Na ₂ O + K ₂ O is <5.0% by weight,
MgO 0-8% by weight
CaO 0-20% by weight
SrO 0-20% by weight
BaO 0-80% by weight, in particular BaO 0-60% by weight, provided that
TiO ₂ 0-10% by weight
Preferably> 0.5 to 10% by weight,
ZrO ₂ 0 to 3% by weight
CeO ₂ 0-10% by weight
Fe ₂ O ₃ 0 to 3% by weight
Preferably 0 to 1% by weight
WO _{30 to} 3% by weight
Bi ₂ O ₃ 0-80% by weight
MoO ₃ 0 to 3% by weight
SnO ₂ 0 to 2% by weight
ZnO 0-15 wt%
Preferably 0-5% by weight
PbO 0-70% by weight, provided that
ΣAl ₂ O ₃ + B ₂ O ₃ + BaO + PbO + Bi ₂ O ₃ is 10 to 80% by weight, Hf, Ta, W, Re, Os, Ir, Pt, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy , Ho, Er, Tm, Yb and / or Lu are present in an oxide form in a content of 0 to 80% by weight,
As well as compositions having normal concentrations of fining agents.

  Other particularly preferred embodiments of the glass composition according to the present invention are as follows.

SiO ₂ 55~85 weight%
B ₂ O ₃ > 0 to 35% by weight
Al ₂ O ₃ 0-20% by weight
Li ₂ O <0.5 wt%
Na ₂ O <0.5 wt%
K ₂ O <0.5% by weight, provided that
ΣLi ₂ O + Na ₂ O + K ₂ O is <1.0 wt%,
MgO 0-8% by weight
CaO 0-20% by weight
SrO 0-20% by weight
BaO 15-60% by weight, in particular BaO 20-35% by weight, provided that
ΣMgO + CaO + SrO + BaO is 15 to 70% by weight,
In particular, 20-40% by weight,
TiO ₂ 0-10% by weight
Preferably> 0.5 to 10% by weight,
ZrO ₂ 0 to 3% by weight
CeO ₂ 0-10% by weight
Preferably 0 to 1% by weight
Fe ₂ O ₃ 0 to 1% by weight
WO _{30 to} 3% by weight
Bi ₂ O ₃ 0-80% by weight
MoO ₃ 0 to 3% by weight
SnO ₂ 0 to 2% by weight
ZnO 0-10% by weight
Preferably 0-5% by weight
PbO 0-70% by weight, provided that
ΣAl ₂ O ₃ + B ₂ O ₃ + BaO + PbO + Bi ₂ O ₃ is 15 to 80% by weight,
As well as normal concentrations of fining agents.

  It is particularly preferred that the glass does not contain alkali except for inevitable impurities.

Therefore, it is particularly preferable to use borosilicate glass for the display according to the present invention for the hollow glass body of the light emitting means. Borosilicate glass has SiO ₂ and B ₂ O ₃ as the first component, alkaline earth oxides such as CaO, MgO, SrO and BaO as the other components and optimally Li ₂ O, for example. Includes alkali oxides such as Na ₂ O and K ₂ O.

Borosilicate glasses with a content of 5 to 15% by weight of B ₂ O ₃ show a high chemical stability. Borosilicate glass with a content of 15 to 25% by weight of B ₂ O ₃ shows good processability. Borosilicate glass having a content of 25 to 35% by weight of B ₂ O ₃ exhibits a particularly low dielectric loss factor tan δ when used as lamp glass. This makes the borosilicate glass particularly advantageous for use according to the invention in lamps with electrodes attached to the outside of the lamp bulb, for example in gas discharge lamps without electrodes. It is.

In the first aspect of the invention, the base glass usually contains at least 30% by weight or at least 40% by weight of SiO ₂ , with at least 50% by weight and preferably at least 55% by weight being particularly suitable. A completely preferred minimum amount of SiO ₂ is 57% by weight. The maximum amount of SiO ₂ is 85% by weight, in particular 75% by weight, 73% by weight and in particular up to 70% by weight of SiO ₂ are quite particularly suitable. Furthermore, the ranges of 50 to 70% by weight and 55 to 65% by weight are quite particularly preferred. Glass with a very high content of SiO ₂ is characterized by a small dielectric loss factor tan δ, and therefore, when taking into account the quotient tan δ / ε ′, the light emitting means with external electrodes used in the present invention, For example, suitable for fluorescent lamps without electrodes.

B ₂ O ₃ is used in the present invention in an amount greater than 0% by weight, preferably in an amount greater than 0.2% by weight, preferably in an amount greater than 2% by weight or 4% by weight or 5% by weight and in particular It is contained in an amount of at least 10% by weight or at least 15% by weight, with at least 16% by weight being particularly preferred. The maximum amount of B ₂ O ₃ is a maximum of 35% by weight, but a maximum of 32% by weight is preferred. A maximum of 30% by weight is particularly preferred.

Although the glass used for the glass hollow body may not have Al ₂ O ₃ in each case, it is usually 0.1%, in particular 0.2% by weight, of Al ₂ O ₃ . Include in minimum amount. A minimum amount of 0.3% by weight is preferred. A minimum amount of 0.7, in particular at least 1.0% by weight, is particularly preferred. The maximum amount of Al ₂ O ₃ is usually 25% by weight, with a maximum of 20% by weight, in particular 15% by weight being preferred. A range of 14 to 17% by weight is quite particularly preferred. In some cases it has been found that a maximum amount of 8% by weight, in particular 5% by weight, is sufficient.

The total alkali oxide is preferably <5% by weight, preferably <1% by weight. It is particularly preferred that the glass composition has no alkali except for inevitable impurities. Li ₂ O is preferably in an amount of 0 to 5, in particular <1.0% by weight, Na ₂ O is preferably in an amount of 0 to 3, in particular <3.0% by weight and K ₂ O is preferably in an amount of 0 to 0%. 9, in particular in amounts of <5.0% by weight. A minimum amount of ≦ 0.1 wt% or ≦ 0.2 wt% and in particular ≦ 0.5 wt% respectively is preferred.

  The alkaline earth oxides MgO, CaO and SrO are contained in the present invention in amounts of 0 to 20% by weight and in particular in amounts of 0 to 8% by weight or 0 to 5% by weight. The content of individual alkaline earth oxides is a maximum of 20% by weight for CaO, but in individual cases a maximum of 18, especially a maximum of 15% by weight is sufficient. In some cases it has been found that a maximum content of 12% by weight is sufficient. Despite the fact that the glass according to the invention has no calcium component, the glass according to the invention usually contains at least 1% by weight of CaO. A content of at least 2% by weight, in particular at least 3% by weight, is preferred. In fact, a minimum amount of 4% by weight has proven appropriate. The lower limit for MgO is 0% by weight in each case. However, at least 1% by weight and preferably at least 2% by weight are suitable. The maximum amount of MgO in the glass is 8% by weight, with a maximum of 7 and especially a maximum of 6% by weight being preferred. SrO may be omitted from the glass. However, it is preferred that an amount of 1% by weight, in particular at least 2% by weight, is contained.

  In order to adjust the quotient calculated from tan δ and ε ′ as small as possible according to the present invention, the glass composition of the glass hollow body contains a highly polarizing element in the form of an oxide in the glass matrix. Such highly polarizable elements in the form of oxides are Ba, Cs, Hf, Ta, W, Re, Os, Ir, Pt, Pb, Bi, La, Ce, Pr, Nd, Sm, Eu, Gd. , Tb, Dy, Ho, Er, Tm, Yb and / or Lu oxides.

  It is preferable that at least one of these oxides is contained in the glass composition. A mixture of two or more of these oxides can also be present. Accordingly, at least one of these oxides is contained in an amount of> 0 to 80% by weight, preferably 5 to 75% by weight, particularly preferably 10 to 70% by weight, in particular 15 to 65% by weight. Furthermore, 15 to 60% by weight, 20 to 55% or 20 to 50% by weight is preferable. More preferred is 20 to 45% by weight, especially 20 to 40% by weight or 20 to 35% by weight. It is particularly advantageous that at least one of the oxides does not fall below 15, in particular 18, preferably 20% by weight.

It is particularly preferred that Cs ₂ O, BaO, PbO, Bi ₂ O ₃ and rare earth metal oxides such as lanthanum oxide, gadolinium oxide, ytterbium oxide are present in the glass composition of the glass hollow body.

  At least 15% by weight, more preferably 18% by weight, in particular 20% by weight, very particularly preferably more than 25% by weight, of one or more highly polarisable elements, in the form of oxides, contained in the glass composition It is particularly preferred that

The CeO ₂ content is preferably 0 to 5% by weight. 0 to 1 and especially 0 to 0.5% by weight are preferred. It is preferable that the content of Nd ₂ O ₃ is 0 to 5% by weight. An amount of 0 to 2, in particular 0 to 1% by weight is particularly suitable. It is particularly preferred that Bi ₂ O ₃ is present in an amount of 0 to 80% by weight, preferably 5 to 75% by weight, particularly preferably 10 to 70% by weight, in particular 15 to 65% by weight. Furthermore, 15 to 60% by weight, 20 to 55% by weight or 20 to 50% by weight is preferable. More preferred is 20 to 45% by weight, especially 20 to 40% by weight or 20 to 35% by weight.

  Therefore, by adding at least one of these polarizable oxides with the above-mentioned surprisingly high content, the glass properties can be appropriately influenced. Therefore, the total power loss can be significantly reduced and reduced to a minimum as compared to the glass normally used for light emitting means for displays.

  Accordingly, the total of all alkaline earth oxides is preferably 0-80% by weight, in particular 5-75% by weight, preferably 10-70% by weight, particularly preferably 20-60% by weight, in the present invention. Particularly preferred is 20 to 55% by weight. Furthermore, 20 to 40% by weight is preferable.

The glass of the glass hollow body may not have ZnO, but preferably has a minimum amount of 0.1% by weight and a maximum amount of at most 15% by weight. A maximum amount of 6% or 3% by weight may be quite appropriate. ZrO ₂ is contained in an amount of 0 to 5% by weight, particularly 0 to 3% by weight. A maximum content of 3% by weight has proven to be sufficient in many cases. Furthermore, WO ₃ and MoO ₃ can be contained separately from one another in amounts of 0 to 5% by weight or 0 to 3% by weight, in particular 0.1 to 3% by weight.

Glass is particularly suitable in the present invention when the total Al ₂ O ₃ + B ₂ O ₃ + BaO + PbO + Bi ₂ O ₃ is in the range of 15-80% by weight, preferably 15-75% by weight, especially 20-70% by weight. It became clear that there was. Since B ₂ O ₃ is usually used in a maximum amount of 35% by weight, the remaining 45% by weight is one or more of the polarizable oxides such as BaO, Bi ₂ O ₃ , Cs ₂ O and PbO. Distributed to.

  In a preferred embodiment, the PbO content is adjusted to 0 to 70% by weight, preferably 10 to 65% by weight, more preferably 15 to 60% by weight. It is particularly preferred that 20 to 58% by weight, 25 to 58% by weight, 25 to 55% by weight, especially 35 to 50% by weight are contained.

In a special embodiment, when the PbO content is above 50% by weight, especially when this content is above 60% by weight, the glass contains more than 3% by weight, in particular more than 4% by weight. It can be added in a greater content or greater than 5% by weight. However, it is better not to contain more than 10% by weight. However, the requirement for the quotient tan δ / ε ′ <5 × 10 ⁻⁴ is still satisfied. When the glass according to the present invention does not contain PbO, it is preferred in the present invention that these glasses do not contain alkali.

These glasses, even without having a TiO ₂ these glasses basically, in order to adjust the "UV edge" (absorption of UV light), can also contain TiO _2. The maximum content of TiO ₂ is preferably 10% by weight, in particular at most 8% by weight, with 5% by weight being preferred. A preferred minimum content of TiO ₂ is 1% by weight. It is preferred that at least 80% to 99% by weight, in particular 99.9 or 99.99%, of TiO ₂ contained is present as Ti ⁴⁺ . In some cases, a content of 99.999% Ti ⁴⁺ was found to be significant. The melt is preferably produced under oxidizing conditions. Oxidation conditions must in particular mean conditions where titanium is present in the above amounts as Ti ⁴⁺ or is oxidized at this stage. Such oxidation conditions are easily achieved in the melt, for example, by the addition of nitrates, in particular alkali nitrates and / or alkaline earth nitrates. Oxidized melt can also be obtained by injection of oxygen and / or dry air. Furthermore, it is possible to generate the oxidized melt using, for example, a burner adjusting means for oxidizing during melting of the mixture.

When a TiO ₂ content of the glass composition is> 2% by weight and a mixture having a total content of> 5 ppm Fe ₂ O ₃ is used, this mixture is clarified with As ₂ O ₃ and melted with nitrate It is preferred that The addition of nitrate is preferably made as an alkali nitrate having a content of> 1% by weight. The purpose is to suppress the coloring of the glass (formation of ilmenite (FeTiO ₃ ) mixed oxide) in the visible range. Furthermore, clarification with Sb ₂ O ₃ and nitrate is possible.

  Despite the addition of nitrate, preferably alkali nitrate and / or alkaline earth nitrate, to the glass during melting, the concentration of nitrate is as high as 0.01% by weight and maximum after fining in the finished glass. In this case, it is at most 0.001% by weight.

The content of Fe ₂ O ₃ is preferably 0 to 5% by weight, with amounts of 0 to 1 and especially 0 to 0.5% by weight being preferred. The content of MnO ₂ is 0 to 5% by weight, and an amount of 0 to 2, particularly 0 to 1% by weight is preferable. The component MoO ₃ is contained in an amount of 0 to 5% by weight, preferably 0 to 4% by weight, and As ₂ O ₃ and / or Sb ₂ O ₃ are each separately present in the glass according to the invention. It is contained in 0 to 1% by weight, and the minimum content is preferably 0.1, in particular 0.2% by weight. The glass according to the invention, in a preferred embodiment, optionally contains a small amount of 0 to 2% by weight of SO ₄ ²⁻ and Cl ⁻ and / or F ⁻ in the same amount of 0 to 2% by weight. .

Fe ₂ O ₃ can be added to the glass in an amount up to 1% by weight. It is preferable that the content is lower than the numerical value. As long as it contains iron, iron, for example by introduction of nitrate-containing raw material, by oxidation conditions during melting, the procedure moves to the oxidation stage 3 ^+. This minimizes fading to the visible wavelength range. Fe ₂ O ₃ is preferably contained in the glass in a content of <500 ppm. Fe ₂ O ₃ is generally present as an impurity.

In particular, when TiO is added at a content of> 1% by weight, the fading of the glass in the visible wavelength range is particularly pronounced that the glass melt is substantially free of chloride, in particular chloride and / or Sb ₂ O ₃ is at least partially prevented by not being added for fining in the glass melt. That is, it has been found that the blue coloration of the glass, which occurs particularly when using TiO ₂ , is avoided when the chloride as a fining agent is omitted. The maximum content of chloride and fluoride is 2% by weight, in particular 1% by weight, according to the invention. A maximum content of 0.1% by weight is preferred.

  Furthermore, it has been found that sulfates used as fining agents, for example, also cause glass fading in the visible wavelength range, similar to the agents. Therefore, it is also preferable to omit the sulfate. The maximum sulfate content is 2% by weight, in particular 1% by weight, according to the invention. A maximum content of 0.1% by weight is preferred. In this protection right, the visible wavelength range means a wavelength range of 380 nm to 780 nm.

Furthermore, for glass, it has been found that the above disadvantages are further prevented when fining is carried out with As ₂ O ₃ and under oxidizing conditions. It is preferred that the glass contains 0.01 to 1 wt% As ₂ O ₃ .

Although the glass is very stable to solarization upon UV radiation, the solarization stability is PdO, PtO ₃ , PtO ₂ , PtO, RhO ₂ , Rh ₂ O ₃ , IrO ₂ and / or Ir _2. It has been found that the slight inclusion of O ₃ can be further increased. The usual maximum content of such substances is at most 0.1% by weight, preferably at most 0.01% by weight. In this case, a maximum of 0.001 weight is particularly preferred. The minimum content is usually 0.01 ppm for these purposes. At least 0.05 ppm and especially at least 0.1 ppm are preferred.

  The glass composition is designed for light emitting means with external electrodes, for example EEFL light emitting means without electrode bushings, in which the glass is not melted with the outer electrode bushings. In the case of an EEFL backlight without an electrode, since light is focused by an electric field (Einkopplung), an appropriate quotient calculated from a loss angle and a dielectric constant within the scope of the present invention is described below. Glass compositions are likewise particularly suitable.

SiO ₂ 35~65 weight%
B ₂ O ₃ 0-15% by weight
Al ₂ O ₃ 0-20% by weight
Preferably 5 to 15% by weight
Li ₂ O 0-0.5 wt%
Na ₂ O 0 to 0.5 wt%
K ₂ O 0 to 0.5 wt%, however,
ΣLi ₂ O + Na ₂ O + K ₂ O is 0 to 1% by weight,
MgO 0-6% by weight
CaO 0-15% by weight
SrO 0-8% by weight
BaO 1-20% by weight, in particular BaO 1-10% by weight,
TiO ₂ 0-10% by weight
Preferably> 0.5 to 10% by weight,
ZrO ₂ 0 to 1% by weight
CeO ₂ 0 to 0.5% by weight
Fe ₂ O ₃ 0-0.5 wt%
WO _{30 to} 2% by weight
Bi ₂ O ₃ 0-20% by weight
MoO ₃ 0-5% by weight
SnO ₂ 0 to 2% by weight
ZnO 0-5% by weight
Preferably 0 to 3% by weight
PbO 0-70% by weight, provided that
ΣAl ₂ O ₃ + B ₂ O ₃ + BaO + PbO + Bi ₂ O ₃ is 8 to 65% by weight, Hf, Ta, W, Re, Os, Ir, Pt, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy , Ho, Er, Tm, Yb and / or Lu are present in an oxide form in a content of 0 to 80% by weight,
As well as normal concentrations of fining agents.

  Furthermore, the following glass compositions are also preferable.

SiO ₂ 50~65 weight%
B ₂ O ₃ 0-15% by weight
Al ₂ O ₃ 1 to 17% by weight
Li ₂ O 0-0.5 wt%
Na ₂ O 0 to 0.5 wt%
K ₂ O 0 to 0.5 wt%, however,
ΣLi ₂ O + Na ₂ O + K ₂ O is 0 to 1% by weight,
MgO 0-5% by weight
CaO 0-15% by weight
SrO 0-5% by weight
BaO 20-60% by weight, in particular BaO 20-40% by weight,
TiO ₂ 0 to 1% by weight
ZrO ₂ 0 to 1% by weight
CeO ₂ 0 to 0.5% by weight
Fe ₂ O ₃ 0-0.5 wt%
Preferably 0 to 1% by weight
WO _{30 to} 2% by weight
Bi ₂ O ₃ 0-40% by weight
MoO ₃ 0-5% by weight
ZnO 0-3 wt%
SnO ₂ 0 to 2% by weight
0-30 wt% PbO, especially
10-20% by weight of PbO, provided that
ΣAl ₂ O ₃ + B ₂ O ₃ + BaO + PbO + Bi ₂ O ₃ is 10 to 80% by weight,
Hf, Ta, W, Re, Os, Ir, Pt, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and / or Lu are in the form of oxides and are 0. Present in a content of ˜80% by weight,
As well as normal concentrations of fining agents.

All said glass compositions preferably have the said amount of Fe ₂ O ₃ and very particularly preferably substantially free of Fe ₂ O ₃ .

In a further preferred embodiment, the glass composition according to the invention is made of SiO _{2 with} or without doping. Doped means within the framework of the present invention oxides for doping, in particular the oxides individually listed in each quantity.

  The preferable composition range of the glass composition for the glass hollow body of this aspect is as follows.

SiO ₂ 90~100 weight%
TiO ₂ 0-10% by weight
CeO ₂ 0-5% by weight.

In this case, the upper limit of the content of SiO ₂ occurs at 100% by weight. The lower limit of the doping oxide, ie the sum of all lower limits, is subtracted. For example, when the content of TiO ₂ is 5 to 10% by weight and the content of CeO ₂ is 2 to 5% by weight, the upper limit for SiO ₂ is calculated as 100− (5 + 2) = 93% by weight. It is quite particularly preferred that pure SiO ₂ is present which does not contain any doping material.

The maximum content of TiO ₂ , especially for UV blocking by glass, is 10% by weight, preferably at most 8% by weight, in particular at most 5% by weight, with a content between 1 and 4% by weight Is possible. The CeO ₂ content is at most 5% by weight, and amounts below 0 to 4% by weight, in particular 0 to 3% by weight, more preferably below 1% by weight can also be adjusted. Other oxides already mentioned can be included as well.

Processes for producing SiO ₂ glasses, in particular amorphous SiO ₂ (quartz glass, quartz glass), are, for example, vapor phase separation, borosilicate glass leaching (Auslaugung) and subsequent calcination of glass melts. And manufacturing.

The glass of the present invention is suitable for the production of flat glass, particularly for the production thereof, particularly by the float process, except for the glass of SiO ₂ described above. Furthermore, these glasses are suitable for the production of tube glass, and the Danner method is particularly preferred. However, it is also possible to manufacture glass tubes by the bellows pulling method or the A pulling method. Suitable for the production of tubes having a diameter of at least 0.5 mm, in particular at least 1 mm and an upper limit of at most 2 cm, in particular at most 1 cm. A particularly preferred tube diameter is between 2 mm and 5 mm. It has been found that such a tube has a wall thickness of at least 0.05 mm, in particular at least 0.1 mm, with at least 0.2 mm being particularly preferred. The maximum wall thickness is at most 1 mm, and wall thicknesses of at most <0.8 mm or <0.7 mm are preferred.

  The glass of the light emitting means having an external electrode has a glass composition, or further comprises a glass composition having an ultraviolet blocking effect to a desired degree.

Said glass, in particular borosilicate glass or SiO ₂ pure or doped with impurities, is particularly well suited for the production of lamp glasses for light-emitting means with external electrodes for displays. This is because these glasses meet the requirements for the quotient calculated from the loss angle tan δ and the relative dielectric constant ε ′. The glass is used for the backlighting of the display according to the invention, for example on an LCD display or LCD image receiving screen, and as a light source, a backlit display (passive display, so-called display with backlight unit). For example, in computer monitors, in particular in TFT devices, and in scanners, advertising screens, medical instruments, and devices for flight and space flight and navigation technologies, mobile phones and PDAs (personal digital assistants). Because of this use, such fluorescent emitters have very small dimensions, and thus the lamp glass has only a very thin thickness.

  A preferred display and image receiving screen is a so-called flat display, using a laptop, in particular a flat backlight device.

  Hereinafter, the present invention will be described in detail with reference to the drawings. 1-3 illustrate the use of a backlight lamp in a display according to the present invention. The glass hollow body of the backlight lamp contains or consists of a suitable glass composition.

  FIG. 1 shows a special use for such an application. For these applications, individual miniaturized fluorescent tubes 110 made of suitable glass are used in parallel to each other and provided on a plate 130 having a plurality of indentations 150. These depressions reflect the emitted light to the display according to the invention. A reflective layer 160 is covered above the reflective plate 130. This reflective layer evenly scatters the light emitted from the fluorescent tube 110 in the direction of the plate 130 as a kind of reflector, thus providing an even illumination of the display. This device is preferably used for fairly large displays, for example in the case of television receivers.

  In the embodiment of FIG. 2, the fluorescent tube 210 can be attached to the display 202 on the outside. In that case, the light is evenly distributed (auskoppeln) on the upper surface of the display by a light guide type plate 250 used as a light guide, so-called LGP (light guide plate).

It is also possible to use such a backlight device in which the light emitting unit 310 is located directly on the structured disk 315. This is illustrated in FIG. In this case, the structure is generated by a plurality of parallel ridges having a predetermined width (W _rib ), so-called barriers 380, in the disk, a channel having a predetermined depth and a predetermined width (d _channel and W _channel ). , So that there is a discharge fluorescent material 350 in these channels. In this case, the channel forms a plurality of radiating hollow spaces 360 with a disk having a phosphorescent layer 370. The backlight device shown in FIG. 3 is a gas discharge lamp having no electrode. That is, there is no bushing and only the external electrodes 330a and 330b are provided. The cover disk 410 shown in FIG. 3 may be an opaque diffuser disk or a transparent disk, depending on the structure of the system. The lamp device shown in FIG. 3 without electrodes is a so-called EEFL (External Electrode Fluorescent Lamp) device. Such a device forms a large flat backlight and is also called a flat backlight.

  FIG. 4 shows a schematic representation of a display according to the invention comprising a light emitting means with external electrodes, for example EEFL. A display, for example an LCD display 1, is shown, for example with respective glass covers on the upper and lower sides. Furthermore, a liquid crystal layer having a plurality of polarizers 2 is shown. In FIG. 4, a plurality of fluorescent gas discharge lamps 3 are provided in a hollow shape, and this lamp is a round tube surrounded by special glass 6. Of course, other cross sections can also be used. Heat is released through the lower surface 5 of the display. The light distribution unit has the reference numeral 4.

  FIG. 5 shows a schematic cross-sectional view of a typical light emitting means. For example, shapes having round, oval, round, or rectangular cross sections are shown.

  In FIG. 6, in a schematic form, a part of a lamp, in particular an EEFL glass tube, is shown. The glass tube was measured in the following example, and the measurement results are summarized in Table 9. FIG. 6 shows the end of the glass tube 1000 in schematic form. The glass tube 1000 has a glass with a thickness d, and the diameter of the glass tube is 2r. The electrode has the reference 1010 and extends along the outer surface of the tube 1000 over a length l.

  FIG. 7 shows an electrical equivalent circuit diagram (RC member) of the lamp structure shown in FIG.

The contact of the EEFL glass tube is here formed by a cylinder. This cylinder has a radius r (typically 0.3 mm <r <10 mm), a glass tube thickness d (with a size of 0.1 mm <d <0.5 mm), and a height l of all contacts. (With a size of 0.5 cm <l <5 cm). In this case, the total capacity is approximated by a plate capacitor of thickness d and radius r together with a cylindrical capacitor having radius r and height l. This geometry is shown in FIG. The total geometric capacity of this geometry is:

However, the last coefficient G has only a geometric effect, ε ₀ = (μ ₀ c ² ) ⁻¹ = 8.85418710 ⁻¹² AsV ⁻¹ m ⁻¹ is an influence coefficient, and ε ′ is a dielectric constant The real part. The frequency-dependent virtual impedance of such a capacitor is

Is given by. However, ω = 2πv represents an angular frequency and i = √−1. Since the dielectric medium is formed by glass, the resistance loss of the glass is a major cause for the overall loss of the discharge lamp. The total resistance of the contact area is

It is. Where ε ″ is the imaginary part of the dielectric function, which generally depends on the frequency. When a voltage is applied at the contact region, the electrical resistance is provided parallel to the capacitor as shown in FIG. This leads to an impedance Z as follows:

All the electrical losses of such RC members (however, the ohmic resistance R is much greater than the reactance of the capacitor at the frequency used. R >> | X _c |) results in: .

The total current l _tot is mainly determined by the discharge lamp. The voltage that drops near the contact cap is derived by capacitance as follows:

Part of the current that passes through the resistor is

It is determined by.

The dielectric loss of all such contacts is as follows:

Since the EEFL lamp has two such contacts, the result is multiplied by a factor of 2 and a geometric factor is inserted. Because of the generally mechanical nature of the dielectric function, ε ′ (ω) and ε ″ (ω) are written.

This means that using the expression tan δ = ε ″ / ε ′ for the dielectric loss tangent,

Bring.

In this case, an important result is obtained that the dielectric loss is proportional to the magnitude tan δ (ω) / ε ′ (ω) according to the material, irrespective of the cap geometry.

It should be noted that an accurate calculation using the current through the resistor and capacitor yields the following results:

Since tan δ is on the order of 10 ⁻⁴ for most glasses, the denominator tan ² δ (ω) can actually be ignored for most glasses.

  Examples of the present invention will be described below. These examples demonstrate the teachings of the present invention, but are not intended to limit the invention.

Hereinafter, the glass composition for the glass body of the light emitting means having the external electrode is shown, and the quotient tan δ / DZ is shown respectively. DZ is a dielectric constant. Quotient of all the glass compositions according to the present invention, when the tanδ is indicated in units of ^10-4, below significantly 5, when the tanδ is shown in absolute units, significantly 5 × 10 ^-4 As it falls below, it meets the prescribed requirements.

  Hereinafter, other glass compositions and examples relating to the present invention will be described.

  Tables 3 to 8 below show other glass compositions. Tables 3 to 7 show glasses according to the present invention, and Table 8 lists comparative examples. It is preferable that the glass concerning this invention does not have an alkali.

  Tables 9.1 and 9.2 show the dielectric loss of EEFL lamps for the glass compositions of Examples 15, 16 and 17 of Tables 3 and 4 and the comparative example of Table 8.

  The dielectric loss tan δ / ε 'for temperatures of 25 ° C., 150 ° C. and 250 ° C. and excitation frequencies of 10 kHz, 35 kHz and 75 kHz has been described in detail. The power loss of the lamp is proportional to the quotient tan δ / ε ′. The dielectric loss of the EEFL lamp was derived under the assumption that a cylindrical capacitor was provided at both ends of the lamp, as described above in connection with FIGS.

  In addition, Table 9 lists the individual parameters used in the measurement, such as lamp tube radius, lamp glass thickness, contact length, geometric factor and coefficient (Vorfaktor), etc. Has been up.

When tan δ is shown in units of 10 ⁻⁴ , all numerical values relating to the quotient of the glass composition according to the present invention are below the upper limit of 5, and when tan δ is shown in absolute units, the upper limit of 5 × 10 ^-4 , and thus significantly less dielectric loss than the comparative example, where the quotient exceeds the critical upper limit.

Therefore, the measurement confirms that it is not important that the individual values (Einzelwerte) of the loss angle tan δ and the dielectric constant are adjusted separately as low as possible. The two values must be related to each other. Surprisingly, based on a given value, the quotient calculated from the two parameters represents the critical value used to adjust the properties of the glass material and represents only tan δ or only ε ′. It was confirmed that there was nothing. Thus, according to the present invention, the total power loss of the light emitting means with external electrodes can be reduced appropriately by the properties of the glass.

表９．１のすべての値に該当する数の例：
ｔａｎδ／ε’（但し１０^−４のオーダーのｔａｎδ）＝６．９（２５℃の場合）、あるいは、ｔａｎδが絶対値であって、ｔａｎδ／ε’＝０．０００６９。 Table 9.1 below shows the calculated quotient tan δ / ε ′ (calculated from the measured values tan δ and ε ′).

Examples of numbers that correspond to all values in Table 9.1:
tan δ / ε ′ (where tan δ on the order of 10 ⁻⁴ ) = 6.9 (in the case of 25 ° C.), or tan δ is an absolute value and tan δ / ε ′ = 0.00069.

  From Table 9.1 above, it can be directly seen that the glass according to the present invention shows a quotient that is 20 times greater than that of the comparative example at 250 ° C.

Given these quotients, each power loss for the light emitting means was calculated with the parameters listed below.

in this case,

Holds.

However,
l (unit: mA) 7
Pipe radius r (mm) 2
Glass thickness d (mm) 0.3
Contact length (mm) l (mm) 18
Frequency (kHz) 10
Frequency (kHz) 35
Frequency (kHz) 70
Geometric coefficient G (1 / m) 1.17
Coefficient 2 / (2π) ^* G ^* | ^* | / e0 (J) 2069740.52
The exact calculation is made by equation (11) derived earlier. However, G can be substituted for the above formula (12). In that case,

Holds. However,
π = 3.141592654
ε ₀ = 8.8542 10 ⁻¹² As / (Vm).

１０Ｈｚ，３５Ｈｚおよび７０Ｈｚの、用いられた周波数が選択された。何故ならば、重要なランプ、特に、外部電極を有する特にＥＥＦＬが、通常は、約７０ｋＨｚの周波数で作動されるからである。このことは、既に引用された文献（Cho G.他、J.Phys. D:Appl. Phys.第３７巻（２００４）、２８６３〜２８６７頁およびCho T.S.他、Jpn. J. Appl. Phys.第４１巻（２００２）、７５１８〜７５２１頁）からも明らかになる。すなわち、本発明に係わるガラスを有するランプは、作動条件下でテストされた。 The parameters result in power losses summarized in Table 9.2 below for different frequencies 10 Hz, 35 Hz and 70 Hz.

The frequencies used were selected: 10 Hz, 35 Hz and 70 Hz. This is because important lamps, especially EEFL with external electrodes, are usually operated at a frequency of about 70 kHz. This is the case with previously cited references (Cho G. et al., J. Phys. D: Appl. Phys. Vol. 37 (2004), 2863-2867 and Cho TS et al., Jpn. J. Appl. Phys. 41 (2002), pages 7518 to 7521). That is, the lamp with glass according to the present invention was tested under operating conditions.

  During the measurement, a voltage in the range of 500 V to 6 kV, in particular 2 kV, preferably 1 kV, was applied and reciprocally connected between intermediate values, for example between +2 kV and −2 kV. This alternating voltage may be, for example, sinusoidal, sawtooth, triangular or rectangular. Other shapes are possible as well.

  FIG. 8 illustrates sinusoidal and rectangular voltages having intermediate values between +2 kV and −2 kV. In this case, an inverter was used to generate a high voltage from the existing line voltage. This inverter is an electronic member that uses a voltage in the range between 500V and 6kV over time. This inverter is electrically connected in front of the lamp.

  From Table 9.1, it can be seen that the glass used in the display according to the present invention exhibits up to 36 times less power loss than the comparative glass. Thus, these glass compositions actually exhibit very little dielectric loss, and therefore there is much less heat generation in the glass than the comparative glass, which It is supported that good efficiency and thus a longer lifetime result.

  Another problem of EEFL is so-called pinhole burning, which means dielectric breakdown when the voltage is high. This causes glass leakage when such breakdown occurs. This is described in detail in Cho et al. Surprisingly, the glass compositions used, preferably those listed in the table, in particular the glass compositions of Examples 15, 16 and 17, which are alkali free glasses, It became clear that no burning was shown. Undesirable breakdown did not occur in the tested glass, even for voltages up to 6 kV. This confirms suitability for use in the field of lamps, especially in the case of EEFl lamps.

Thus, in accordance with the present invention, a backlit display is described. The glass hollow body of the light emitting means contains a glass composition. In this glass composition, the glass characteristics can be appropriately influenced by adjusting the quotient calculated from the loss angle tan δ and the relative dielectric constant ε ′. By paying attention to the upper limit according to the present invention with respect to the quotient of 5 × 10 ⁻⁴ , first, in accordance with the teachings of the present invention, the total power loss of the glass composition is reduced to a minimum, and thus also in a light emitting means having an external electrode, It is possible to maintain optimum efficiency.

1 shows a schematic representation of a display according to the invention with a miniaturized backlight device. 1 shows a schematic representation of a display according to the present invention having a backlight device with external electrodes. 1 shows a schematic representation of a display according to the present invention having a fluorescent emitter attached laterally. 2 shows a schematic representation of a display according to the invention with an EEFL lamp. 1 shows a schematic diagram of a typical cross-sectional area of a light emitting means used in accordance with the present invention. 1 shows a schematic of a lamp structure based on the measurement in the following example. The electrical equivalent circuit schematic (RC member) of the example of the lamp | ramp shown in FIG. 4 is shown. 2 shows examples of sinusoidal and rectangular periodic voltages.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... LCD display 2 ... Polarizer 3 ... Fluorescent gas discharge lamp 4 ... Light distribution unit 5 ... Lower surface of display 6 ... Special glass 310 ... Light emission unit 315 ... Structured disk 330a ... External electrode 330b ... External electrode 350 ... Discharge Fluorescent material 360 ... Radiation hollow space

Claims (48)

Backlit displays for mobile phones, cars, televisions, computers, homes and cameras, in particular flat displays, comprising a glass hollow body and at least one light emitting means with external electrodes,
The glass composition for the glass hollow body of the light emitting means is such that tan δ / ε ′ <5 × 10 ⁻⁴ is applied to the quotient calculated from the loss angle (tan δ) and the dielectric constant (ε ′). A display characterized by being selected. 2. A display according to claim 1, characterized in that the quotient is tan [delta] / [epsilon] '<4 * 10 < ^-4 >, in particular tan [delta] / [epsilon]'<3.5 * 10 < ^-4 >. 3. The display according to claim 1, wherein the quotient is tan δ / ε ′ <3 × 10 ⁻⁴ , in particular tan δ / ε ′ <2.5 × 10 ⁻⁴ . By adjusting the quotient tan δ / ε ′ <5 × 10 ⁻⁴ , the high efficiency of the light emitting means is reduced by a slight power loss (P _loss ).

(Where ω is the angular frequency, tan δ is the loss angle, ε ′ is the dielectric constant, d is the capacitor thickness (here, the glass thickness), A is the electrode area, l is the current intensity, and ε _0. The display according to any one of claims 1 to 3, wherein the display is caused by an influence coefficient = 8.8542 10 ^-12 As / (Vm)).   The display according to claim 1, wherein a size of the display is in a range of 50 × 50 mm to 4 × 5 m.   6. The display according to claim 1, wherein the display comprises a glass plate, in particular a structured glass plate, a liquid crystal layer, a polarizing unit and other glass plates for the display. display.   The display according to claim 1, wherein the display has a light distribution unit including a polymer having scattering centers, glass, phase-separated glass, or glass ceramic.   8. The display of claim 7, wherein the light distribution unit has heterogeneously distributed scattering centers for optimal homogeneous light distribution.   The light distribution unit has a structured or predetermined surface roughness with an rms value on the order of the wavelength of the light, preferably 20 nm <rms <100.000 nm, particularly preferably 10 nm <rms <10000 nm. The display according to claim 7 or 8, wherein:   The light distribution unit is formed as a hollow body, and a wall portion of the hollow body guides light by reflection, and light is dispersed from the hollow body by surface roughness (auskoppeln). The display according to any one of claims 7 to 9.   11. A display according to any one of the preceding claims, characterized in that the light emitting means is a discharge lamp, in particular a fluorescent lamp, particularly preferably an EEFL lamp.   12. A display as claimed in claim 11, characterized in that the light emitting means have a circular, oval, rectangular and / or planar, rectangular cross section. Tan δ / ε ′ <5 × 10 ⁻⁴ is applied to the glass hollow glass of the light emitting means having the external electrode, and the operating frequency is 5 to 200 kHz, preferably 10 to 150 kHz, particularly preferably 20 to 100 kHz. The display according to claim 11 or 12, wherein the display is in the range.   14. The display according to claim 1, wherein the glass used for the hollow glass body is selected from glasses having a high polarizability (dielectric constant ε ′> 5). . The glass used for the glass hollow body is selected from glasses having low electrical conductivity (especially tan δ <20 × 10 ⁻⁴ , particularly preferably tan δ <1 × 10 ⁻⁴ ). 15. A display according to any one of the preceding claims.   The display according to claim 1, wherein the glass for the glass hollow body is selected from glasses having ultraviolet blocking.   The UV blocking in the glass is adjusted in particular by including rare earth or transition metal ions selected from Ti, Ce, W, Nb, Bi, Yb, Fe, Ni in the glass matrix. The display according to claim 16.   The display according to claim 16, wherein the ultraviolet blocking is adjusted by providing an inner layer or an outer layer of a glass hollow body of the light emitting means.   19. A display as claimed in any one of the preceding claims, wherein the glass hollow body has a filling of gas selected from Hg gas, noble gas, in particular Xe gas or a mixture of these gases. .   The inner layer of the glass hollow body has a fluorescent layer made of a solid powder doped with rare earth ions for converting ultraviolet light or blue light into white light as a whole. The display according to any one of the above.   The glass of the glass hollow body is doped with impurities by fluorescent rare earth ions and / or transition metal ions in order to convert ultraviolet light or blue light into totally white light. Item 21. The display according to any one of Items 1 to 20.   The display according to claim 20 or 21, characterized in that the rare earth ions are selected from Ce, Eu, Tm, Tb, Dy and / or Gd.   The contact of the light emitting means with the glass hollow body is made from a) a metal or a thin metal plate, b) an immersion layer (Tauchbeschichtungen) made of a metal or a metal-containing conductive material, c) a conductive lacquer or d) a conductive adhesive tape. The display according to claim 1, wherein the display is selected.   24. For temperature management in the light emitting means, one or more aerators and / or liquid cooling for cooling cooling or active cooling for passive cooling are provided. The display according to any one of the above.   The light-emitting means having an external electrode is activated with an alternating voltage of 0.5 to 10 kV, particularly preferably 0.8 to 6 kV, at a frequency of 5 to 200 kHz, preferably 10 to 150 kHz, particularly preferably 20 to 100 kHz. 25. A display as claimed in any one of the preceding claims, characterized in that means are provided.   26. A display as claimed in claim 25, characterized in that the means for activating the light-emitting means with external electrodes use a sinusoidal signal, preferably a rectangular signal.   27. A display as claimed in claim 25 or 26, wherein the means is an electronic start-up unit that generates voltage and signal shapes.   28. A display as claimed in claim 27, wherein the electronic activation unit comprises a current limiter.   The light emitting means is a high-pressure lamp, and in this high-pressure lamp, the filling gas to which pressure is applied so that a continuous spectrum is generated, or Hg gas and / or Xe gas is contained as the filling gas. 29. The method according to any one of claims 1 to 28, characterized in that when heated, there is an additional strong impact propagation of the Hg and / or Xe line spectrum that can be triggered by an external electrode. Display as described.   The glass hollow body includes Ba, Cs, Hf, Ta, W, Re, Os, Ir, Pt, Pb, Bi, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, 2. A glass composition comprising at least one highly polarizing element selected from the group consisting of oxides of Tm, Yb and / or Lu in the form of an oxide in a glass matrix. 30. The display according to any one of 29.   Said one or more highly polarizable elements are present in the form of oxides in at least 8% by weight, preferably 12% by weight, particularly preferably 15% by weight, in particular 20% by weight or more. 31. A display as claimed in claim 30.   Said one or more highly polarizable elements are present in the form of oxides in at least 20% by weight, preferably 25% by weight, particularly preferably 35% by weight, in particular 40% by weight or more. 31. A display as claimed in claim 30. The glass hollow body has the following glass composition, that is,
SiO ₂ 55~85 weight%
B ₂ O ₃ > 0 to 35% by weight
Al ₂ O ₃ 0 to 25% by weight
Preferably 0-20% by weight
Li ₂ O <1.0 wt%
Na ₂ O <3.0 wt%
K ₂ O <5.0% by weight, provided that
ΣLi ₂ O + Na ₂ O + K ₂ O is <5.0% by weight,
MgO 0-8% by weight
CaO 0-20% by weight
SrO 0-20% by weight
BaO 0-80% by weight, in particular BaO 0-60% by weight, provided that
TiO ₂ 0-10% by weight
Preferably> 0.5 to 10% by weight,
ZrO ₂ 0 to 3% by weight
CeO ₂ 0-10% by weight
Fe ₂ O ₃ 0 to 3% by weight
Preferably 0 to 1% by weight
WO _{30 to} 3% by weight
Bi ₂ O ₃ 0-80% by weight
MoO ₃ 0 to 3% by weight
SnO ₂ 0 to 2% by weight
ZnO 0-15 wt%
Preferably 0-5% by weight
PbO 0-70% by weight, provided that
ΣAl ₂ O ₃ + B ₂ O ₃ + BaO + PbO + Bi ₂ O ₃ is 10 to 80% by weight, Hf, Ta, W, Re, Os, Ir, Pt, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy , Ho, Er, Tm, Yb and / or Lu are present in an oxide form in a content of 0 to 80% by weight,
The display according to any one of claims 1 to 32, comprising a glass composition having a normal concentration of fining agent. The glass hollow body has the following glass composition, that is,
SiO ₂ 55~85 weight%
B ₂ O ₃ > 0 to 35% by weight
Al ₂ O ₃ 0-20% by weight
Li ₂ O <0.5 wt%
Na ₂ O <0.5 wt%
K ₂ O <0.5% by weight, provided that
ΣLi ₂ O + Na ₂ O + K ₂ O is <1.0 wt%,
MgO 0-8% by weight
CaO 0-20% by weight
SrO 0-20% by weight
BaO 15-60% by weight, in particular BaO 20-35% by weight, provided that
ΣMgO + CaO + SrO + BaO is 15 to 70% by weight,
In particular, 20-40% by weight,
TiO ₂ 0-10% by weight
Preferably> 0.5 to 10% by weight,
ZrO ₂ 0 to 3% by weight
CeO ₂ 0-10% by weight
Preferably 0 to 1% by weight
Fe ₂ O ₃ 0 to 1% by weight
WO _{30 to} 3% by weight
Bi ₂ O ₃ 0-80% by weight
MoO ₃ 0 to 3% by weight
SnO ₂ 0 to 2% by weight
ZnO 0-10% by weight
Preferably 0-5% by weight
PbO 0-70% by weight, provided that
ΣAl ₂ O ₃ + B ₂ O ₃ + BaO + PbO + Bi ₂ O ₃ is 15 to 80% by weight,
The display according to any one of claims 1 to 32, comprising a glass composition having a normal concentration of fining agent. The glass hollow body has the following glass composition, that is,
SiO ₂ 35~65 weight%
B ₂ O ₃ 0-15% by weight
Al ₂ O ₃ 0-20% by weight
Preferably 5 to 15% by weight
Li ₂ O 0-0.5 wt%
Na ₂ O 0 to 0.5 wt%
K ₂ O 0 to 0.5 wt%, however,
ΣLi ₂ O + Na ₂ O + K ₂ O is 0 to 1% by weight,
MgO 0-6% by weight
CaO 0-15% by weight
SrO 0-8% by weight
BaO 1-20% by weight, in particular BaO 1-10% by weight,
TiO ₂ 0-10% by weight
Preferably> 0.5 to 10% by weight,
ZrO ₂ 0 to 1% by weight
CeO ₂ 0 to 0.5% by weight
Fe ₂ O ₃ 0-0.5 wt%
WO _{30 to} 2% by weight
Bi ₂ O ₃ 0-20% by weight
MoO ₃ 0-5% by weight
SnO ₂ 0 to 2% by weight
ZnO 0-5% by weight
Preferably 0 to 3% by weight
PbO 0-70% by weight, provided that
ΣAl ₂ O ₃ + B ₂ O ₃ + BaO + PbO + Bi ₂ O ₃ is 8 to 65% by weight, Hf, Ta, W, Re, Os, Ir, Pt, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy , Ho, Er, Tm, Yb and / or Lu are present in an oxide form in a content of 0 to 80% by weight,
The display according to any one of claims 1 to 32, comprising a glass composition having a normal concentration of fining agent. The glass hollow body has the following glass composition, that is,
SiO ₂ 50~65 weight%
B ₂ O ₃ 0-15% by weight
Al ₂ O ₃ 1 to 17% by weight
Li ₂ O 0-0.5 wt%
Na ₂ O 0 to 0.5 wt%
K ₂ O 0 to 0.5 wt%, however,
ΣLi ₂ O + Na ₂ O + K ₂ O is 0 to 1% by weight,
MgO 0-5% by weight
CaO 0-15% by weight
SrO 0-5% by weight
BaO 20-60% by weight, in particular BaO 20-40% by weight,
TiO ₂ 0 to 1% by weight
ZrO ₂ 0 to 1% by weight
CeO ₂ 0 to 0.5% by weight
Fe ₂ O ₃ 0-0.5 wt%
Preferably 0 to 1% by weight
WO _{30 to} 2% by weight
Bi ₂ O ₃ 0-40% by weight
MoO ₃ 0-5% by weight
ZnO 0-3 wt%
SnO ₂ 0 to 2% by weight
0-30 wt% PbO, especially
10-20% by weight of PbO, provided that
ΣAl ₂ O ₃ + B ₂ O ₃ + BaO + PbO + Bi ₂ O ₃ is 10 to 80% by weight,
Hf, Ta, W, Re, Os, Ir, Pt, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and / or Lu are in the form of oxides and are 0. Present in a content of ˜80% by weight,
The display according to any one of claims 1 to 32, comprising a glass composition having a normal concentration of fining agent.   37. A display according to any one of the preceding claims, wherein the alkali content in the glass composition of the glass hollow body is <1.0% by weight.   The display according to any one of claims 1 to 37, wherein the glass of the glass hollow body has no alkali.   39. The content of BaO in the glass composition of the glass hollow body is more than 15% by weight, preferably more than 18% by weight. display.   The display according to any one of claims 1 to 38, wherein the content of BaO in the glass composition of the glass hollow body is more than 20 wt%.   The content of BaO in the glass composition of the glass hollow body is between 20 wt% and 80 wt%, preferably between 20 and 60 wt%. The display according to item 1.   The content of PbO in the glass composition of the glass hollow body is more than 50% by weight, in particular more than 60% by weight, the alkali content is more than 3% by weight, preferably more than 4% by weight. 42. A display as claimed in any one of claims 1 to 41, characterized in that it is much, particularly preferably more than 5% by weight.   42. Any of claims 1-41, wherein when the glass composition of the glass hollow body does not contain PbO, the alkali content is <1.0 wt%, preferably no alkali. The display according to item 1.   43. When the glass composition of the hollow glass body contains PbO, the content of BaO is <10% by weight, preferably <5% by weight, particularly preferably BaO is not contained. The display according to any one of the above. The display according to any one of 1 to 32, wherein the glass of the glass hollow body contains SiO ₂ containing or not containing a doping oxide, or made of this substance. The glass of the glass hollow body has the following composition:
SiO ₂ 90~100 weight%
TiO ₂ 0-10% by weight
CeO ₂ 0 to 5% by weight
Has, the upper limit of the content of SiO ₂ occurs at 100% by weight, with the exception of SiO _2, claim 45, characterized in that all the lower is drawn oxides described herein Display. Display according to claim 45 or 46 glass of the glass hollow bodies, characterized by comprising of SiO _2.   48. Mobile phone in a display according to any one of claims 1 to 47, in particular in an electronic device such as an LCD display for use of an image receiving screen and a display device, in a computer monitor such as a TFT device. Use in scanners, advertising screens, medical instruments, and devices for flight and space flight, as well as navigation technology and personal digital assistants (PDAs).

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