Title of Invention


Abstract The invention relates to a lighting system made up of phosphor particles dispersed in a solid and durable matrix allowing handing by a user, the matrix is in the form of a thin layer in adhesion with a substrate.
The present invention relates to the special shaping of
phosphore particles known elsewhere, capable of
guaranteeing, on the one hand, high mechanical and
optical properties, such as mechanical strength under
the most exacting handling conditions, strength impact
resistance, abrasion resistance, crush and crack
resistance and, possibly, delamination in the case of a
deposit on a substrate, shear strength, flexural
strength, etc. and, on the other hand, transparency,
the virtual absence of haze, controlled light
transmission between values that can approach 100% and
low values in the case of highly scattering materials,
optical homogeneity, absence of degradation and
yellowing, particularly under the effect of excitation,
The term phosphore particles refers to particles that
are able to emit light, particularly in the long
wavelength region of the visible spectrum, under the
effect of excitation by UV radiation, an electron beam,
X-rays, gamma radiation or an electric field, these
particles having a size, for example, that lies between
a few nanometers and a few microns, and being used
particularly in lamps in the form of powdered masses.
In addition, application FR-A1-2 829 4 81 mentions
separately the coating of "phosphore particles with a
stabilizing sodium silicate film on the one hand and,
on the other hand, the deposition of dispersions
possibly with other phosphores, in the form of
transparent films on a glass substrate. However, the
document does not specify how a film, or all the more a
transparent film, is to be obtained.
The invention now provides composites of phosphore
particles capable of preserving integrity of state and

shape over long periods, under normal conditions of use
(assembly, installation, cleaning, etc.).
This objective is achieved by the invention, the
subject of which is an illumination system consisting
of phosphore particles dispersed in a solid, durable
matrix, while enabling it to be handled by a user.
Phosphore particles falling within the scope of the
invention are, for example:
Sr2P2O7: Eu
(Sr,Ca,Ba)5 (PO4)3Cl:Eu
BaMg2Al16O27: Eu
BaMg2Al16O27: Eu, Mn
CaWO4: Pb
Ba2P2O7: Ti
Zn2SiO4 :Mn
MgAl11O19 : Ce, Tb, Mn
3 . 5MgO. 0 . 5MgF2. GeO2 : Mn
Y2O3 : Eu
(Ba, Sr, Mg) 3Si2O7: Pb
YPO4: Ce
LaPO4 : Ce

(KF,MgF2) :Mn
MgF2: Mn
Zn2SiO4 :Mn,As
Y2O2S : Tb
ZnS: Ag
InBO3 : Tb+InBO3 : Eu
ZnS:Ag+ZnS:Cu(or ZnS:Cu,Au)+Y2O2S:Eu
InBO3:Tb+InBO3:Eu+ZnS :Ag
YBO3 : Tb

YBO3 : Eu
SrAl2O4 :Eu,Dy
These phosphore particles or these mixtures of
phosphore particles are characterized by the emission
of long wavelength radiation in the visible region,
corresponding to different colors, white light, or in
the IR or UV. The last three mentioned in the above
list are notable for the intensity, persistence and
duration of their activity, after any excitation source
has been removed, in particular at night.
The invention therefore makes it possible to provide
handlable, reliable, strong solid illuminating objects
that can coat a multitude of forms, such as a coating
on a substrate, capable of illuminating in various
colors, opening the way to the most novel and varied
esthetic or artistic creations.
Preferably, the particles are phosphores within the
visible region, in which most of the applications
envisaged below present the greatest interest.
The particles can be excited by electromagnetic
radiation in the UV, visible, IR region or by X-rays or
by gamma rays, or by a beam of particles (electrons,
ions) or by an electric field. Excitation by UV may be
derived from the deexcitation of a plasma or of an
ionized gas.
According to a preferred embodiment, the matrix is
inorganic and comprises, in a particularly preferred
manner, lithium silicate. It should be stated that
sodium silicates, and to a lesser extent potassium
silicates, are suitable if need be for an opaque

illumination system, lithium silicate being
particularly recommended for a transparent illumination
system. Accordingly, it has been observed with sodium
silicate that there is a migration to the surface of a
very hygroscopic and scattering crust based on sodium
hydroxide that is continually regenerated. Lithium
silicate proves to be notable for the possibility of
distributing therein, in a uniform manner, high
concentrations of phosphore particles in the most
separated state possible, as well as for its
compatibility with many substrates, including glass. On
account of the fact that the matrix comprises lithium
silicate, it will be understood that, in reality, the
matrix is a product of the partial or total conversion
of lithium silicate, in particular into silica, in
which lithium silicate and/or lithium remain entirely
According to another embodiment, the matrix comprises a
product of the polymerization/polycondensation of a
silicon alkoxide such as tetraethoxysilane (TEOS),
tetramethoxysilane (TMOS), methyltriethoxysilane
(MTEOS) and the like. These precursors of the matrix
provide excellent conditions for compatibility with
many phosphore particles, among those previously
In a practical and effective embodiment of the
invention, the matrix is in the form of a thin layer
adhering to a substrate consisting in particular of
glass, for example in the form of a sheet, but also of
a slab intended to constitute an electronic display
screen, a tube, in particular for lighting, fiber or
fabric or plastic. For the latter, reference may be
made to any generally transparent plastic such as
polycarbonate, polyvinyl butyral, a polyolefin such as
polyethylene or polypropylene, poly(ethylene
terephthalate) , polyurethane, acrylic polymer such as
poly(methyl methacrylate), an ionomer resin, various

copolymers, etc., the use of which is of course limited
by possible formation of a thin layer at. a temperature
capable of affecting or degrading the plastic.
The invention comprises two main variants.
According to the first variant, the phosphore particles
are in aqueous suspension and their size is at most
equal to 100 nm, preferably 3 0 nm, preferably 10 nm,
and the assembly that they form with the matrix is
According to the second variant, the size of the
phosphore particles lies between 0.5 and 10 nm, it
being possible for particles scattering visible light
to be then advant advantageously incorporated in the matrix
(particles may be involved other than phosphore
particles having a size of, in particular, between
100 nm and 1 µm, in particular between 300 and 700 nm,
such as alumina, or phosphore particles themselves;
these light-scattering particles are dielectric,
semiconduction or conducting particles).
Thus, phosphore particles with a size between 30 and
500 nm are not excluded from the invention, those
having in particular a size at least equal to 400 nm
that are capable of scattering visible light making it
unnecessary to add other scattering particles.
In a particularly advantageous embodiment of the
illumination system of the invention, in the case where
the matrix is in the form of a thin layer adhering to a
substrate, the latter is capable of exciting phosphore
particles, and is in particular an electroconductor, in
particular of the UV electroluminescent type.
In an equally advantageous embodiment, the substrate is
capable of emitting radiation with a waveletngth in the
visible region under suitable excitation. It is then,

for example, made of glass with a cerium content,
capable of emitting blue light under ultraviolet
According to another alternative of the design of the
illumination system, two cases may be distinguished in
the phosphore particles emitting different
wavelengths are associated, separated from each
other and homogenized, so as to produce white
light, yellow light, etc., on the one hand; and
the phosphore particles that are identical or emit
different wavelengths are combined in variable
compositions and/or concentrations, so as to form
signs such as written or similar signs, or for any
other, especially decorative, purpose.
The main processes for preparing the illumination
system of the invention consist of:
cold deposition processes by means of a liquid,
such as spray coating, flow coating, dip coating,
spin coating, screen printing, followed by a heat
treatment at 100-650°C, for example (annealing,
tempering, etc.) according to the nature of the
matrix; or
a vacuum deposition process.
In addition, other subjects of the invention are:
the application of an illumination system as
described above to a transparent device;
the application of the illumination system to a
light-scattering device;
the application of the illumination system to a
lamp, in particular a thin one, or to a device
illuminating at night, in particular for signs, or
for decorative purposes or to a flat lamp as
described in the application WO 04/15739;
the application of the illumination system to
monolithic, laminated, single glazing or multiple

glazing designed for buildings, to a transport
vehicle, such as an automobile rear window, side
window or roof, to any other terrestrial or
aquatic vehicle or aircraft, to street furniture,
such as a bus shelter, to a road sign or to an
advertisement panel, to an aquarium, to a store
window, to a glasshouse, to interior furniture, to
a mirror, to a screen for a display system of the
computer type, to a television, to a telephone, to
electrically controllable glazing such as
electrochromic glass, to liquid crystals, to
electroluminescent material or to photovoltaic
It is stated that in this last application, the
association of the illumination system with glazing is
compatible with all known practical applications
thereof, either on the same face as that supporting the
illumination system, above or below, or on other faces
of the glazing, namely a hydrophobic/oleophobic,
hydrophilic/oleophilic, anti-soiling photocatalytic
layer, a multilayer reflecting thermal radiation (solar
protection layer) or IR (low-e layer), antireflection
layer, etc.
As a valuable example, mention may be made of glazing
that separating, for example, an enclosure in a
building from the outside atmosphere, the inner face of
which is illuminating according to the invention, and
the outer face of which is electrochromic, that is to
say capable of being darkened by applying a voltage to
the layer. In this way, the functionality obtained is
that of illuminating the interior while blocking off
external light.
In the illuminating glazing application according to
the invention, the glazing guarantees maximum
transparency and maximum optical quality in the absence

of excitation, and constitutes an illuminating surface
in the presence of excitation.
The screen application for a display system can be
generalized to any application requiring a light source
and means of treatment thereof, in the form of a light
It consists in particular of backlight.
The invention is illustrated by the following examples
of embodiments.
YVO4:Eu nanoparticles were first of all synthesized by
a colloidal method.
The entire synthesis of colloidal solutions was carried
out in water at a temperature of 60°C. The insoluble
citrate complex was formed by mixing 0.75 equivalents
of sodium citrate (0.1 mol/1, 15 ml) with 1 equivalent
of (Y,Eu) (NO3)3 (0.1 mol/1, 20 ml). Addition of 0.75
equivalents of an Na3VO4 solution with a pH of 12.5
(0.1 mol/1, 15 ml) caused the precipitate to dissolve
and the reaction to start. The pH of the clear solution
obtained was 7.6. At the end of 30 minutes of reaction,
heating was stopped. The colloidal solution obtained
was then dialyzed in water at neutral pH so as to
eliminate various counterions (Na+, NO3-) or any
unreacted species. Following the dialysis step, the
concentration of the colloidal solution was of the
order 10-2 mol/1.
The colloidal solutions were then concentrated by
evaporation to dryness under mild conditions (40°C
under vacuum). The powder obtained was easily
redispersed in a very small quantity of water which
enabled very concentrated colloidal solutions to be

obtained (up to 2 mol/1, that is 400 g/1) Moreover, the
size measured by light scattering after redispersion
(10V3 nm) was identical to that of the colloid obtained
after dialysis: the colloids underwent no aggregation
during the concentration step. As a consequence, the
concentrated colloidal solutions were optically
Transparent luminescent films were prepared in the
following way: 0.2 to 1 ml of lithium silicate (30% by
mass in water, pH 12) was added to 4 ml of the
concentrated colloidal solution of YVO4:Eu
nanoparticles. The sol obtained was filtered (glass
fiber prefilter and 0.45 µm filter) and then deposited
by centrifuging (speed of rotation 1000 rpm for 60
seconds) onto a float glass substrate (5x5 cm2). The
thin films obtained were finally annealed at 450°C for
12 hours. The purpose of this heat treatment was to
consolidate the film mechanically and to increase the
luminescence (elimination of hydroxyl groups that
inhibit the luminescence of europium ions). After
annealing, the thin films were perfectly transparent
and had a thickness of between 0.2 and 0.7 µm.
The thin films were placed under a UV lamp emitting at
254 nm. Red luminescence, characteristic of europium
ions, was observed within the YVO4 matrix. Luminance
measurements were carried out and confirmed what was
visually observed: light emission was more intense on
the cut edge of the film than in the center. Indeed,
the luminance was 5 Cd/m2 at the center whereas it was
2 0 Cd/m2 at the cut edge.
This example describes the preparation of scattering
luminescent layers.

12.8 g of alumina particles with a mean diameter of
500 nm were added to 176 g of deionized water together
with 0.24 g of polyacrylic acid (50% by weight solution
in water). Sodium hydroxide was then added until a pH
of 10 was reached. 5 g of LaPO4:Ce,Tb particles with a
mean diameter of 2 µm, sold by Nichia, were then added.
The mixture was then homogenized in a turbine for 5
minutes. 11 g of lithium silicate (30% by weight
solution in water) were then added. After 5 minutes of
homogenization in a turbine, the mixture was deposited
on a 10 x 10 cm2 glass substrate by flow coating.
Drying was carried out under an IR lamp (temperature of
the coating approximately 80°C). The coating obtained
had a TL of 60% and haze close to 100%.
Green luminescence produced in the coating was observed
under photoexcitation at 257 nm.

We Claim
1. Lighting system made up of phosphor particles dispersed in a solid and
durable matrix allowing handling by a user, characterized in that the
matrix is in the form of a thin layer in adhesion with a substrate.
2. Lighting system as claimed in claim 1, wherein the particles are phosphor
in the visible domain.
3. Lighting system as claimed in the claim 1 or 2, wherein the particles can
be activated by an electromagnetic radiation in the field of UV, visible, Ir,
either by x-rays or gamma rays, or by a beam of particles (electrons,
ions), or by an electric field.
4. Lighting system as claimed in one of the preceding claims, wherein the
matrix is inorganic.
5. Lighting system as claimed in claim 4, wherein the matrix comprises
lithium silicate.
6. Lighting system as claimed in claim 4, wherein the matrix comprises a
product of polymerization/polycondensation of silicium alkoxide.

7. Lighting system as claimed in one of the preceding claims, wherein the
phosphor particles are in aqueous suspensions, wherein their dimensions
are at the most equal to 100 nm, preferably to 30 nm, preferably to 10
nm, and wherein the unit which they form with the matrix is transparent.
8. Lighting system as claimed in one of the claims 1 to 6, wherein
dimensions of the phosphor particles lie between 0.5 and 10 nm.
9. Lighting system as claimed in claim 8, wherein the matrix comprises
particles diffusing visible light.
10. Lighting system as claimed in one of the preceding claims, wherein the
substrate is fit for activating the phosphor particles, notably electro-
conductor, particularly of electroluminescent type in UV.
11. Lighting system as claimed in one of the claims 1 to 9, wherein the
substrate is ready to emit a wave of wave length of the visible domain
under a suitable activation.
12. Lighting system as claimed in claim 11, wherein the substrate is of glass
with cerium content apt to give out a blue light under ultraviolet radiation.
13. Lighting system as claimed in claim 1, wherein the substrate is of glass,
particularly in form of a sheet, slab, tube, fibre or tissue.
14. Lighting system as claimed in claim 1, wherein the substrate is of plastic.
15. Lighting system as claimed in one of the preceding claims, wherein
phosphor particles emitting different wave lengths are associated there,
individualized and homogenized, so as to produce white light in particular.
16. Lighting system as claimed in one of the claims 1 to 14, wherein phosphor
particles, identical or emitting different wave lengths are associated there
according to variable compositions and/or concentrations, so as to form
signs such as writings or similar, or for any other purpose, particularly
17. A transparent device or a device for diffusing light, or a decorative lighting
device, or a monolithic glazing adaptable in particular to transparent
vehicle, comprising a lighting system as claimed in claims 1 to 16.
The invention relates to a lighting system made up of phosphor particles
dispersed in a solid and durable matrix allowing handling by a user, the matrix is
in the form of a thin layer in adhesion with a substrate.




02694-kolnp-2005-description complete.pdf

02694-kolnp-2005-form 1.pdf

02694-kolnp-2005-form 2.pdf

02694-kolnp-2005-form 3.pdf

02694-kolnp-2005-form 5.pdf

02694-kolnp-2005-international publication.pdf




2694-kolnp-2005-granted-description (complete).pdf

2694-kolnp-2005-granted-examination report.pdf

2694-kolnp-2005-granted-form 1.pdf

2694-kolnp-2005-granted-form 18.pdf

2694-kolnp-2005-granted-form 2.pdf

2694-kolnp-2005-granted-form 3.pdf

2694-kolnp-2005-granted-form 5.pdf


2694-kolnp-2005-granted-letter patent.pdf

2694-kolnp-2005-granted-reply to examination report.pdf


2694-kolnp-2005-granted-translated copy of priority document.pdf

Patent Number 214999
Indian Patent Application Number 02694/KOLNP/2005
PG Journal Number 08/2008
Publication Date 22-Feb-2008
Grant Date 20-Feb-2008
Date of Filing 26-Dec-2005
# Inventor's Name Inventor's Address
PCT International Classification Number H 01 J 1/62
PCT International Application Number PCT/FR04/001575
PCT International Filing date 2004-06-23
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 04/02931 2004-03-22 France
2 03/07573 2003-06-23 France