Title of Invention

A FLAT LAMP AND A PROCESS FOR MANUFACTURING THE LAMP

Abstract A flat lamp (1) comprising at least two glass substrates (2,3) kept mutually parallel and defined in an internal gas-filled space (10), comprising two electrodes (4,5) associated with the glass substrates and away from the internal space (10), each substrate having an internal surface facing the internal space and an external surface facing away from the internal space, in which the internal face (22, 32) of at least one substrate (2, 3) is coated with a phosphor material (6, 7), characterized in that at least one of the electrodes (4, 5) is covered with at least one preferably transparent electrical insulation (2, 3; 14, 15; 16, 17) that may be formed by at least one of the glass substrates (2, 3) incorporating said electrode either within its very thickness or on the external surface or be associated with at least one of the glass substrates (2, 3). The invention also provides a process for manufacturing the lamp.
Full Text The invention relates to the field of luminaires and
more particularly to a flat discharge lamp that can be
used as a decorative or architectural luminaire.
Flat lamps, such as those used for the manufacture of
backlit screen devices, may be formed from two glass
sheets held slightly apart, generally by less than a
few millimeters, and hermetically sealed so as to
contain a gas at reduced pressure, in which an
electrical discharge produces radiation generally in
the ultraviolet range that excites a phosphor
substance, that then emits visible light.
In a standard structure, a glass sheet has, on one and
the same face, two screen-printed coatings, especially
made of silver, in the form of interpenetrating combs
that constitute a cathode and an anode. This face is
turned toward the space containing the plasma gas.
Another glass sheet is kept at a certain distance from
the first one by means of discrete spacers and
optionally by a peripheral frame. Generated between the
anode and the cathode is what is called a coplanar
discharge, that is to say one in a direction hugging
the main surface of the glass substrate, which
discharge excites the surrounding plasma gas. The
electrodes are protected by a dielectric coating
designed to avoid, by capacitive limitation a loss of
material of the electrodes by ion bombardment in the
vicinity of the glass substrate. At least one of the
glass substrate faces turned toward the space
containing the gas furthermore carries a coating of
phosphor material.
This coplanar discharge lamp structure, whose function
is to provide maximum light power with a very thin
device, proves to be very complex. Its high cost means

that it is intended only for high added-value
applications. „
DISCLOSURE OF THE INVENTION
The object of the present invention is to propose a
flat illuminating element capable of offering novel
possibilities in terms of decoration, display and/or
architecture.
In this regard, the subject of the invention is a flat
lamp comprising at least two glass substrates kept
mutually parallel and defined in an.internal gas-filled
space, comprising two electrodes associated
respectively with the two glass substrates and away
from the internal space, in which the internal face of
at least one substrate turned toward said internal
space is coated with a phosphor material, characterized
in that at least one of the electrodes is covered with
at least one preferably transparent electrical
insulation that may be formed by at least one of the
glass substrates or be associated with at least one of
the glass substrates.
The electrical, preferably transparent, insulation thus
allows the electrodes to be electrically isolated from
the outside for safety of the public.
According to one embodiment, at least one electrode is
affixed to the surface of the external face of the
substrate with which it is associated and is covered
with at least one electrical insulation, the electrode
being incorporated into the surface of the glass
substrate or of the electrical insulation.
According to another embodiment, at least one electrode
is incorporated into the electrical insulating
material, either within its very thickness or on the
surface.

According to these embodiments, this electrical
insulation is made of glass or of a transparent plastic
such as polyvinyl butyral (PVB), ethylene/vinyl acetate
(EVA) or polyethylene terephthalate (PET).
According to yet another embodiment, the electrical
insulation is formed by the glass substrate as such,
the electrode being incorporated into its thickness.
One or more other additional, preferably transparent,
electrical insulations, made of glass or of any other
material such as a plastic (PVB, PET EVA) that may also
have other functionalities, for example for providing
an optical effect, especially a colored effect, a
decorative effect, produced by screen printing or
otherwise, with a structured relief, a delustered
effect, or with a scattering layer, etc., may be joined
to this electrical insulation as formed, depending on
the various embodiments.
Thus, joining one or more electrical insulations to the
glass substrate(s) of the lamp makes it possible, apart
from protecting the electrodes, to produce decorative
or illuminating objects incorporating decorative plates
that present flat decorations, for example photographs,
screen printing, enameled decorations, etc.
In particular, an additional electrical insulation is
also formed by another glass substrate that is
laminated to at least one of the glass substrates
constituting the lamp via an intermediate plastic film
or other material, especially a resin, that can make
the two substrates adhere to each other.
According to another feature, the second electrode is
joined in the same way as the first electrode or
according to an alternative embodiment given above.

This structure, by placing the electrodes on the
outside of the enclosure containing the plasma gas at
reduced pressure, allows the manufacturing cost of the
lamp to be considerably lowered, with illumination
characteristics well suited to the use as a luminaire.
In this configuration, the glass substrate acts as
capacitive protection for the electrodes against ion
bombardment.
Furthermore, the problem of connection to the power
supply is solved much more simply than in the case of
the known systems in which the electrical connectors
must pass through the hermetically sealed enclosure
containing the gas.
The term "translucent element" is understood to mean an
element whose constituent material is translucent or
transparent, but also elements made of a material that
can absorb a substantial fraction of the light
radiation but is distributed with respect to the
surface of the substrate in a pattern such that all the
light radiation emitted by the lamp is altered very
little by the element. Such generally translucent
elements may be formed by a grid, an array of wires, an
etched or screen-printed coating, etc.
Preferably, an electrode that can be used in the
invention is in the form of a transparent or
translucent conductive coating deposited directly on
the substrate by standard thin-film deposition, by
etching or by screen printing. In particular, the
electrode is a continuous conductive coating, that is
to say one that entirely covers large areas of the
surface of the substrate.
Advantageously, the two electrodes are continuous
conductive coatings each located on the external face
side of a substrate and at least partly covering the

facing surfaces of said substrates. Preferably, the two
electrodes are transparent coatings.
The continuous and the uniform coatings forming the
electrodes may be manufactured on large substrates by
methods of very high productivity.
The continuous coatings may cover all or part of the
external faces facing the glass substrates. It is
possible to provide only certain areas of the external
surface of one or the substrates so as to create
predefined illumination regions on one and the same
surface. These regions may optionally constitute
decorative patterns or constitute a display, such as a
logo or a mark.
For example, the continuous coatings may be in the form
of an array of parallel bands, having a bandwidth of
between 3 and 15 mm, and a non-conducting space between
two adjacent bands, having a width greater than the
width of the bands. These coatings deposited on the two
substrates being offset by 180° so as to prevent two
opposed conducting bands of the two substrates from
facing each other. Advantageously, this makes it
possible to reduce the effective capacitance of the
glass substrates, favoring the supply of the lamp and
its efficiency in terms of lumens/W.
The electrodes may be made of any conducting material
that can be made in the form of a flat element allowing
light to pass through it, in particular that can be
deposited as a thin layer on glass or on a plastic
film, such as a PET film, as a coating that lets light
through it. According to the invention, it is preferred
to form a coating from a conducting metal oxide or an
oxide having electron vacancies, such as fluorine-doped
tin oxide or mixed indium tin oxide.

The electrodes may instead be in the form of a metal
grid incorporated into a film of plastic such as
polyvinyl butyral (PVB), ethylene/vinyl acetate (EVA)
or other plastic, where appropriate inserted between
two plastic sheets.
Likewise, all or part of the internal faces of at least
one of the two substrates may be coated with a phosphor
material. Thus, even if continuous electrodes covering
all of the surface of the glass substrates cause
discharges throughout the volume of the lamp, a
differentiated distribution of the phosphor in certain
regions makes it possible to convert the energy of the
plasma into visible radiation only in the regions in
question, so as to constitute illuminating regions and
juxtaposed transparent regions.
The phosphor material may advantageously be selected or
adapted so as to determine the color of the
illumination within a broad pallet of colors.
According to one embodiment, spaced between the two
glass substrates are spacers made of a nonconducting
material, said spacers keeping the two substrates
apart. These spacers, that may be termed discrete
spacers when their dimensions are considerably smaller
than the dimensions of the glass substrates, may be of
various shapes, for example spheres, bitruncated
spheres with parallel faces or cylinders, but also
parallelepipeds of polygonal cross section, especially
in the form of a cross, as described in document WO
99/56302.
The spacing between the two substrates may be set by
the spacers to a value of around 0.3 to 5 mm,
especially less than or equal to about 2 mm. One
technique of depositing the spacers in vacuum
insulating glazing assemblies is known from
FR-A-2 787 133. According to this process, spots of

adhesive are deposited on a glass sheet, especially spots of
enamel deposited by screen printing, with a diameter less than or
equal to the diameter of the spacers, and the spacers are rolled
over the said glass sheet, which is preferably inclined, so that
a single spacer adheres to each spot of adhesive. The second
glass sheet is then applied to the spacers and a peripheral seal
is deposited.
The spacers are made of a non-conducting material so as not to
participate in the discharges or to cause a short circuit.
Preferably, they are made of glass, especially of the soda-lime
type.
To prevent loss of light by absorption in the material of the
spacers, it is possible to coat the surface of the latter with a
phosphor material identical to or different from that used for
the glass substrate (s) .
In the structure of the flat lamp according to the invention, the
gas pressure in the internal space may be around 0.05 to 1 bar,
advantageously around 0.05 to 0.6 bar. The gas used is an
ionizable gas that can form a plasma ( a "plasma gas"),
especially xenon or neon, by themselves or as a mixture.
According to one embodiment, the lamp may be produced by firstly
manufacturing a sealed enclosure in which the intermediate air
cavity is at atmospheric pressure, and then by creating a vacuum
and introducing the plasma gas at the desired pressure. According
to this embodiment, one of the glass substrates includes at least
one hole drilled through its thickness and obstructed by a
sealing means.
The subject of the invention is also a process for manufacturing
the lamp, comprising the steps in which :

optionally, at least one electrode is deposited
on one of the glass substrates;
the phosphor is screen-printed on at least one
of the glass substrates, one of which is provided with
a hole drilled through its thickness and on the
opposite side from the electrode if the latter is
deposited on the same substrate;
spacers are deposited on one of the glass
substrates;
the glass substrates are joined together so as
to be parallel;
the internal space is sealed by means of a
peripheral sealing material;
the atmosphere contained in the internal space
is replaced, via the hole, with the plasma gas; and
the hole is obstructed by a sealing means;
optionally, at least one first electrical
insulation is joined to at least one glass substrate,
the electrical insulation being intended to cover or to
incorporate, internally or on the surface, the
electrode with which one of the faces of said substrate
has to be associated, or intended to cover the
electrode that is associated with a second electrical
insulation that is joined to the first electrical
insulation.
To replace the atmosphere with the gas, it is possible
to use a method that involves pumping through a double-
or multiple-glazing structure, such as the method
described for example in document EP-A-645 516. The
latter proposes, as sealing material, a suspension of
solder glass frit. This material is placed in the form
of a bead at the external end of the hole right at the
start of manufacture, a vacuum is created through this
component and is then softened so as to obstruct the
hole.
Another process is described in FR-A-2 774 373 that
proposes, as sealing material, a low-melting-point

alloy. This material may be placed in the form of a
component having a shape matched to the external end of
the hole right at the start of manufacture, a vacuum is
created through this component and then it is melted in
order to seal it to the wall of the hole so as to
obstruct the latter.
A preferred process according to the invention consists
in obstructing the hole with a sealing pad that covers
the external orifice of the hole. This pad,
advantageously made of metal, may be bonded to the
glass substrate by welding.
The flat lamp according to the invention may be used as
a luminaire for illumination and/or decoration
purposes. The dimensions of the luminaire may be of the
order of those current enclosures with so-called "neon"
tubes, or much larger, for example at least 1 m2. Using
the flat lamp offers better visual comfort than these
tubes, by emitting more diffuse light, and ensures a
much longer lifetime.
The glass substrates may be of any shape: the outline
of the substrates may be polygonal, concave or convex,
especially square or rectangular, or curved, with a
constant or variable radius of curvature, especially
round or oval.
The flat lamp according to the invention may
advantageously be used as a luminaire capable of
illuminating simultaneously by both its main faces.
This is because its structure includes no opaque or
reflecting layer capable of limiting the transmission
of light on one side or the other of the lamp. However,
for esthetic reasons, it is possible to prevent
illumination through one face or part of one face of
the lamp, for example in order to contributa to the
formation of the desired pattern. Similarly, the lamp
itself may be provided with such a screen, or else this

screen may be joined to it when mounting the final
luminaire.
With reference to the foregoing description, the
invention also relates to the application of a lamp as
described to the production of architectural or
decorative elements that illuminate and/or have a
display function, such as flat luminaires, illuminating
walls, especially suspended walls, illuminating tiles,
etc.
Other details and features of the invention will become
apparent from the detailed description that follows,
with regard to the appended drawings in which:
figure 1 shows a schematic sectional view of a
flat lamp according to the invention; and
figures 2, 3 and 4 show schematic sectional
views of other embodiments of a flat lamp according to
the invention.
It should be pointed out that for the sake of clarity
the various elements of the objects shown have not
necessarily been drawn to scale.
Figure 1 shows a flat lamp 1 consisting of two
substrates made of glass sheets 2, 3 having a first
face 21, 31, with which a continuous and uniform
conductive coating 4, 5 constituting an electrode is
associated, and a second face 23, 32 that carries a
coating of a phosphor material 6, 7.
The conductive coating may be joined to the substrate
in various ways: it may be deposited directly on the
face 21, 31 of the substrate or else deposited on an
electrical insulation carrier element 14, 15, this
carrier element being joined to the substrate in such a
way that the coating is pressed against the face 21, 31
of the substrate. The electrical insulation 14, 15 may,
for example, be a plastic film of the EVA or PVB type.

Optionally, an additional insulation 16, 17 may be
added to the insulating element 14, 15 of the
electrode.
The sheets 2, 3 are put together with their second
faces 22, 32 carrying the phosphor 6, 7 facing each
other and are joined together by means of a sealing fit
8, the gap between the glass sheets being set (at a
value generally less than 5 mm) by glass spacers 9
placed between the sheets. Here, the gap is around 0.3
to 5 mm, for example 0.4 to 1 mm.
The spacers 9 may have a spherical, cylindrical or
cubic shape, or a shape of any other polygonal, for
example cruciform, cross section. As examples, mention
may be made of the TAGLIA ® cruciform spacers sold by
Display Glass. The spacers may be coated, at least on
their lateral surface exposed to the plasma gas
atmosphere, with a phosphor identical to or different
from the phosphor 6, 7 chosen from standard phosphors.
In the space 10 between the glass sheets is a rare gas,
such as xenon, optionally mixed with neon, at a reduced
pressure, generally around one tenth of an atmosphere.
The conducting layers 4, 5 based on the outside of the
assembly, forming the electrodes, are connected to an
appropriate power supply (not shown) via flexible leads
11.
A glass sheet 2 has, near the periphery, a hole 12
drilled through its thickness, the external orifice of
which is obstructed by a sealing pad 13, especially
made of copper bonded to the external face of the sheet
bearing the electrode 4.
The lamp is manufactured in the following manner: the
substrates, cut and made to the desired shape, are

produced from a glass sheet, for example about 3 mm in
thickness, coated with a thxn layer of fluorine-doped
Sn02. A through-hole 12 a few millimeters in diameter
is made near the edge of the substrate 2.
The functional phosphor layers 6, 7, and possibly other
functional, for example power supply, elements, are
deposited, especially by screen printing.
The spacers 9 are deposited on the layer 7 of the
substrate 3 at predefined positions, for example by
means of an automaton, and the substrate 2 is applied
with its internal face 22 facing the internal face 32
of the substrate 3. A sealing fritt is deposited around
the internal peripheral band of the two substrates and
a high-temperature sealing operation carried out.
Next, by means of a pump, the atmosphere contained in
the sealed enclosure is removed through the hole 12 and
is replaced with the xenon/neon mixture. When the
desired gas pressure is reached, the sealing pad 13 is
placed over the opening of the hole 12, around which a
bead of welding alloy has been deposited. A heat source
is activated near the weld so as to cause the latter to
soften, and the pad 13 is pressed by gravity against
the orifice of the hole and thus welded to the
substrate 2, forming a hermetic plug.
This structure makes it possible to manufacture a lamp
with standard glass products, glass coated with
fluorine-doped Sn02 (electrodes) being widely used in
glazing assemblies. Then, the addition of the
electrical insulation 14, 15 being carried out in a
known manner depending on the type of material, by
casting a cold resin or by hot bonding of a
thermoplastic sheet.
In the embodiment shown in figure 2, the structure of
the lamp basically repeats the structure of figure 1,

apart from the arrangement of a conductive coating or
electrode 4, 5.
The conductive coating 4, 5 is sandwiched between a
first electrical insulation 14, 15 and a second
electrical insulation, or additional insulation, 16,
17, the combination being joined to the glass sheet 2,
3.
These electrical insulations 14, 15, 16, 17 may be
formed as various combinations that combine, for
example, a glass sheet and/or plastic films, of the PVB
or PET type, or other resins capable of being
adhesively joined to glass products.
Thus, the glass sheet 2, 3 may support, as combination,
a PBV sheet 14, 15 bonded to the glass sheet as first
electrical insulation and, as second electrical
insulation 16, 17, a glass or a plastic film joined to
the PVB sheet, the electrode being placed between the
two electrical insulations.
Another combination of electrical insulations (not
illustrated) is as follows: a PVB sheet is taken as
first electrical insulation, that will serve to bond
the second electrical insulation and carrier of the
electrode, such as a PVB sheet, the electrode being
between the PVB sheet and the PET sheet, and a third
electrical insulation, such as a PVB sheet, that will
cover the PET sheet in order to protect it from being
scratched.
The embodiment shown in figure 3 repeats that of figure
2, except that the electrode is not incorporated at a
face of an electrical insulation but is incorporated
into the thickness of the first electrical insulation
14, 15.

The manufacture of the lamp according to figures 2 and
3 takes place as explained above, without the step of
depositing the conductive coatings. A step of
laminating the electrical insulations provided with
conductive coatings, on the external faces 21, 31 of
the lamp, is carried out after the step of obstructing
the hole in the structure.
In the embodiment shown in figure 4, the structure of
the lamp also basically repeats the structure of figure
1, except for the arrangement of the conductive coating
or electrode 4, 5.
Here, the conductive coating 4, 5 is incorporated into
the glass sheet 2, 3 that constitutes the electrical
insulation as such.
Additional electrical insulations, not shown here, may
be laminated with at least one glass sheet.
The manufacture of the lamp takes place as explained in
the case of figure 1 without the step of depositing the
conductive coatings, since they have already been
incorporated into the glass sheets.
The examples that have just been described in no way
limit the invention.
In particular, in the embodiments that have just been
described the electrodes were formed from coatings
covering the entire surface of the glass sheets, but it
is understood that at least one of the glass sheets may
have a group of electrodes formed from several regions,
each having a surface of greater or lesser area each
covered with a continuous coating.
Moreover, in the embodiments described above, the
alternative ways of assembling the conductive elements
may be applied differently to each of the glass sheets

2, 3 of the structure, it being possible for one glass
sheet to present one form of assembly while the other
glass sheet presents another form of assembly.

WE CLAIM:
1. A flat lamp (1) comprising at least two glass substrates (2,3) kept mutually
parallel and defined in an internal gas-filled space (10), comprising two
electrodes (4,5) associated with the glass substrates and away from the internal
space (10), each substrate having an internal surface facing the internal space
and an external surface facing away from the internal space, in which the
internal face (22,32) of at least one substrate (2,3) is coated with a phosphor
material (6,7), characterized in that at least one of the electrodes (4,5) is
covered with at least one preferably transparent electrical insulation (2,3;
14,15; 16,17) that my be formed by at least one of the glass substrates (2,3)
incorporating said electrode either within its very thickness or on the external
surface or be associated with at least one of the glass substrates (2,3).
2. The lamp as claimed in claim 1, characterized in that at least one electrode
is affixed to the surface of the external face (21,31) of the substrate with which
it is associated and is covered with at least one electrical insulation (2, 3; 14,
15; 16, 17), the electrode being incorporated into the surface of the glass
substrate pr of the electrical insulation.
3. The lamp as claimed in claim 1, characterized in that at least one electrode
is incorporated into the electrical insulating material (2, 3; 14, 15), either within
its very thickness or on the surface.
4. The lamp as claimed in claim 2 or 3, characterized in that the electrical
insulation is made of glass or of a transparent plastic such as polyvinyl butyral
(PVB), ethylene/vinyl acetate (EVA) or polyethylene terephthalate (PET)
5. The flat lamp as claimed in any one of the preceding claims, characterized
in that the electrical insulation (2, 3; 14, 15) associated with the electrode is
assembled with one or more other additional,

preferably transparent electrical insulations (16, 17)
made of glass or of any other material, such as a
plastic.
6. The lamp as claimed in claims 2 and 5,
characterized in that at least one additional
electrical insulation (16, 17) is formed by another
glass substrate that is laminated to at least one glass
substrate (2, 3) via an intermediate plastic film or
other material, especially a resin, that can make the
two substrates adhere to each other.
7. The lamp as claimed in any one of the preceding
claims, characterized in that at least one electrical
insulation (2, 3; 14, 15; 16, 17) constitutes a sheet
exhibiting an optical effect, especially one that is
colored, decorated, structured, diffusing, etc.
8. The lamp as claimed in any one of the preceding
claims, characterized in that the electrodes (4, 5) are
continuous, conducting and transparent coatings, each
located on the external face (21, 31) side of a
substrate (2, 3) and covering at least part of the
facing surfaces of said substrates.
9. The lamp as claimed in claim 8, characterized in
that the electrodes (4, 5) cover all of the external
faces (21, 31) of the glass substrates.
10. The lamp as claimed in claim 8 or 9, characterized
in that the continuous coatings (4, 5) may be in the
form of an array of parallel bands, having a bandwidth
of between 3 and 15 mm, and a non-conducting space
between two adjacent bands, having a width greater than
the width of the bands, these coatings deposited on the
two substrates being offset by 180° so as to prevent
two opposed conducting bands of the two substrates from
facing each other.

11. The lamp as claimed in any one of the preceding
claims, characterized in that the electrodes (4, 5) are
formed from a metal oxide having electronic vacancies,
such as fluorine-doped tin oxide or mixed indium tin
oxide.
12. The flat lamp as claimed in any one of claims 1 to
7, characterized in that an electrode (4, 5) is an
integrated metal grid, where appropriate inserted in
between two plastic sheets, or the electrode is in the
form of a layer deposited on and incorporated into a
plastic film.
13. The lamp as claimed in any one of the preceding
claims, characterized in that at least part of the
internal face (22, 32) of at least one of the two
substrates (2, 3) is coated with a phosphor material
(6, 7) .
14. The lamp as claimed in any one of the preceding
claims, characterized in that the phosphor is selected
in order to determine the color of the illumination.
15. The lamp as claimed in any one of the preceding
claims, characterized in that spacers (9), made of a
non-conducting material, are placed between the two
glass substrates (2, 3) said spacers maintaining the
separation between the two substrates.
16. The lamp as claimed in claim 15, characterized in
that the separation between the two substrates is
around 0.3 to 5 mm.
17. The lamp as claimed in either of claims 15 and 16,
characterized in that the spacers (9) are made of
glass.

18. The lamp as claimed in one of claims 15 to 17, characterized in that the
lateral surface of the spacers (9) is coated with a phosphor material.
19. The lamp as claimed in any one of the preceding claims, characterized in
that the gas pressure in the internal space (10) is around 0.05 to 1 bar.
20. The lamp as claimed in any one of the preceding claims, characterized in
that one of the glass substrates (2) has at least one hole (120 drilled through its
thickness and obstructed by a sealing means (13).
21. The lamp as claimed in any one of the preceding claims, characterized in
that the contour of the glass substrates (2, 3) is polygonal, concave or convex,
or curved with a constant or variable radius of curvature.
22. The lamp as claimed in any one of the preceding claims, characterized in
that it has to illuminating faces.
23. A process for manufacturing a lamp comprising at least two glass
substrates (2, 3) kept mutually parallel and defined in an internal gas-filled
space (10), comprising two electrodes (4,5) associated with the glass substrates
and away from the internal space (10), in which the internal face (22,32) of at
least one substrate (2,3) turned toward said internal space (10) is coated with a
phosphor material (6,7), at least one electrode is affixed to the surface of the
external face (21, 31) of the substrate with which it is associated and is covered
with at least one electrical insulation (14, 15; 16, 17), the electrode being
incorporated into the surface of the glass substrate or into the electrical
insulating material (2, 3; 14, 15) either within its very thickness or on the
surface comprising the steps in which :
the phosphor is screen-printed on at least one of the glass substrates,
one of which is provided with a hole drilled through its thickness and on

the opposite side from the electrode if the latter is deposited on the same substrate;
spacers are deposited on one of the glass substrates;
the glass substrates are joined together so as to be parallel;
the internal space is sealed by means of a peripheral sealing material;
the atmosphere contained in the internal space is replaced, via the hole, with
the plasma gas; and
the hole is obstructed by a sealing means;
optionally, at least one first electrical insulation is joined to at least one glass
substrate, the electrical insulation being intended to cover or to incorporate,
internally or on the surface, the electrode with which one of the faces of said
substrate has to be associated, or intended to cover the electrode that is
associated with a second electrical insulation that is joined to the first
electrical insulation.
24. Architectural or decorative elements for illuminating and / or having a display
function, such as flat luminaries, illuminating walls, especially suspended walls,
illuminating tiles, etc., comprising a lamp as claimed in claims 1 to 22.

A flat lamp (1) comprising at least two glass substrates (2,3) kept
mutually parallel and defined in an internal gas-filled space (10),
comprising two electrodes (4,5) associated with the glass substrates and
away from the internal space (10), each substrate having an internal
surface facing the internal space and an external surface facing away
from the internal space, in which the internal face (22, 32) of at least one
substrate (2, 3) is coated with a phosphor material (6, 7), characterized
in that at least one of the electrodes (4, 5) is covered with at least one
preferably transparent electrical insulation (2, 3; 14, 15; 16, 17) that
may be formed by at least one of the glass substrates (2, 3) incorporating
said electrode either within its very thickness or on the external surface
or be associated with at least one of the glass substrates (2, 3). The
invention also provides a process for manufacturing the lamp.

Documents:

337-KOLNP-2005-FORM 27-1.1.pdf

337-KOLNP-2005-FORM 27.pdf

337-KOLNP-2005-FORM-27.pdf

337-kolnp-2005-granted-abstract.pdf

337-kolnp-2005-granted-claims.pdf

337-kolnp-2005-granted-correspondence.pdf

337-kolnp-2005-granted-description (complete).pdf

337-kolnp-2005-granted-drawings.pdf

337-kolnp-2005-granted-examination report.pdf

337-kolnp-2005-granted-form 1.pdf

337-kolnp-2005-granted-form 13.pdf

337-kolnp-2005-granted-form 18.pdf

337-kolnp-2005-granted-form 2.pdf

337-kolnp-2005-granted-form 26.pdf

337-kolnp-2005-granted-form 3.pdf

337-kolnp-2005-granted-form 5.pdf

337-kolnp-2005-granted-reply to examination report.pdf

337-kolnp-2005-granted-specification.pdf

337-kolnp-2005-granted-translated copy of priority document.pdf


Patent Number 228773
Indian Patent Application Number 337/KOLNP/2005
PG Journal Number 07/2009
Publication Date 13-Feb-2009
Grant Date 10-Feb-2009
Date of Filing 04-Mar-2005
Name of Patentee SAINT-GOBAIN GLASS FRANCE
Applicant Address LEA MIROIRS, 18, AVENUE D'ALSACE, F-92400 COURBEVOIE
Inventors:
# Inventor's Name Inventor's Address
1 LEBAIL, YANNICK 73, RUE DU JEU DE 1'ARC, F-60150 CHEVINCOURT
2 ZHANG, JINGWEI 38, RUE DES RUELLES, F-91300 MASSY
3 BERTIN-MOUROT, THOMAS 20, RUE DE LA GLACIERE, F-75013 PARIS
4 NEUILLET, ALAIN 29, RUE GEORGES CLEMENCEAU, APPARTMENT N°85, F-60400 NOYON
PCT International Classification Number H01J 65/04,9/26
PCT International Application Number PCT/FR2003/002415
PCT International Filing date 2003-07-30
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 02/10020 2002-08-06 France