FR3084355A1 - ENAMELLED SUBSTRATE, AUTOMOTIVE LIGHT GLASS DEVICE WITH SUCH SUBSTRATE AND ITS MANUFACTURE. - Google Patents

Abstract

The subject of the invention is an enamelled substrate for a glazed automotive light device (and its manufacture) with a first glass sheet (1) comprising a diffusing layer (2) in enamel, in a vitreous material of thickness E1 at least 5µm and at most 20µm, glassy material is based on zinc borosilicate and / or bismuth. The matrix is porous, said diffusing elements are porosities of gas or vacuum (3) of characteristic size, in particular a diameter, of at least 0.2 μm. The first glass sheet and diffusing layer assembly having: - a light transmission factor of at least 75%, - a blurring of at most 30% and at least 1%.

Description

ENAMELLED SUBSTRATE, AUTOMOTIVE LIGHT GLASS DEVICE WITH SUCH SUBSTRATE AND ITS MANUFACTURE

The invention relates to the field of enamelled substrates used to form glazed automotive light devices by means of a peripheral light source. Inorganic light emitting diodes are used to make luminous glazing for motor vehicles. The light emitted by the diodes is introduced by the edge into the glazing forming a guide, the light being extracted from the glazing by a diffusing layer on the glazing, defining the luminous surface, such as a solid surface of enamel containing dielectric diffusing particles as alumina particles.

This diffusing layer is translucent in the off state. This luminous glazing then has a very cloudy appearance in the area of the diffusing layer. Conventionally, the light transmission of this type of enamel is less than 40%, the blur is 90 to 100%.

The present invention has therefore sought to develop an alternative diffusing enamel which further increases the transparency in the off state while remaining capable of extracting light.

To this end, the invention first relates to an enamelled substrate for a glazed automotive light device, comprising:

a first sheet of preferably colorless glass, preferably silico-soda-lime, in particular with a refractive index nO at 550 nm of 1.4 to 1.6, in particular of thickness E0 of at most 10 mm and even of plus 5 or 3mm and preferably at least 0.1mm, 0.3mm or 0.7mm preferably clear or extra-clear, comprising on one (only) first main face (preferably directly) a diffusing enamel layer (solid and / or a pattern in several elements), diffusing layer with preferably a width of at least 0.3mm and even 1mm, in particular occupying a diffusing surface S defined by a length of at least 1mm and even 1cm and the width d '' at least 0.3mm and even 1mm, of thickness E1 at least 5pm better at least 7pm and at most20pm or 15pm, and preferably from 7 to 15pm or 8 to 11pm comprising:

a matrix (transparent), preferably colorless, made of a vitreous material based on zinc borosilicate and / or bismuth, preferably based on zinc borosilicate, in particular the volume fraction in vitreous material being at least 80, 85 or 90% of the volume of the enamel

- the matrix being porous, diffusing elements in the form (preferably only) of gas porosities (air etc.) or vacuum, preferably in the volume, preferably closed porosities - even also on the surface - of dimension (diameter, in particular equivalent diameter) of at least 0.2pm and better still of at least 0.5pm, 0.8pm or 1pm, in particular the volume fraction in porosity being at most 20, 15% or 10% of the volume of the enamel and better at least 1% or 2%

- Said diffusing elements (therefore the diffusing layer) are free from diffusing (solid) particles or with a content by weight of diffusing (solid) particles of at most 10% or 5% of the total weight of the enamel, and even including the unfounded, the crystals, and better the cumulative weight content of diffusing particles (in particular of dimension of at least 0.2 μm) and / or white or colored pigments being at most 10% or 5% of the total weight of the E-mail.

The first glass sheet and diffusing layer assembly presents:

- a light transmission factor of at least 75%, 80%, 85% and even 90% preferably within the meaning of standard EN 410: 1998,

- a blurring (in transmission) of at least 1%, and at most 30% and even 20% or 15%

- and preferably an image clarity (clarity in English) of at least 80%, 90%, 95%.

Surprisingly, such a transparent enamel, which does not leave a white, milky veil on the glazing, is capable of diffusing light through the porosities (forming a refractive index contrast with the matrix).

The choice of zinc borosilicate and / or bismuth, the choice of a range of suitable thickness ensures both control of transparency, low blurring (but sufficient for light extraction) and reproducible porosity formation diffusing. Too small a thickness does not allow the porosities to be trapped. Too much thickness leads to degrading transparency.

The diffusing layer must generate a luminous surface visible to the naked eye and in particular the layer is preferably deposited by screen printing. The limiting size of the diffusing layer is therefore a width of at least 0.3mm.

The diffusing enamel layer is for example in contact with the first main face. It is possible to provide, between the diffusing layer and the first face, a transparent sublayer (mono or multilayer) preferably mineral and even of thickness of at most 1 pm or 0.2 pm as long as the latter does not disturb the guidance and / or the light extraction.

To reduce blurring and increase transparency, the diffusing layer is devoid of or comprises in very reduced content of particles - full and even possibly hollow particles - in particular diffusing or more generally any type of particles (unfounded, crystals, white or colored pigments etc) . In particular, it contains little or no (solid) particles chosen from particles of alumina, zirconia, silica, titanium dioxide, calcium carbonate, barium sulphate. In particular, the diffusing layer is preferably devoid of devitrified zone.

The light transmission factor T _L can be calculated using the illuminant D65, the measurement being made for example using a spectrophotometer provided with an integrating sphere, the measurement at a given thickness is then converted if necessary at the reference thickness of 4mm according to standard EN 410: 1998.

We want the diffusing layer to be as invisible and discreet as possible. Our visual perception can clearly distinguish two different phenomena: diffusion at small angles and over a wider angular range.

Light can be distributed evenly in all directions. This results in contrast reduction and a cloudy, dull-looking image. ASTMD 1003 defines haze or blurring as the amount of light that deviates on average more than 2.5 ° from the incident light beam - expressed as a percentage.

Light can be diffused in a narrow angle with high concentration. This effect describes very well how very fine details can be seen through the sample. The quality of image clarity must be determined at an angle of less than 2.5 degrees.

The blur and even the sharpness are preferably measured by a Hazemeter (such as BYK-Gardner Haze-Gard Plus) preferably according to the ASTDM D1003 standard (without compensation)

We prefer to carry out the measurements before any lamination. For example, the illuminant is placed opposite the first carrier face of the diffusing layer.

Advantageously, the blur is at most 10% or 8%, the sharpness at least 90% or 95%, the light transmission factor is at least 90%.

Preferably, the thickness E1 is stable at ± 3pm.

Furthermore, the diffusing layer may have a gloss in terms of gloss unit (ub) of at least 80, 100 and better still at least 120, reflecting a smooth surface. The diffusing layer is preferably a monolayer (obtained by depositing a single layer based on glass frit).

The size (and even the distribution in thickness) of the porosities can be determined by a sectional observation of the diffusing layer with a scanning electron microscope at a magnification of 1000 times or 2500 times.

In particular, in thickness, there is a single porosity of at least 0.8pm at a time.

The volume fraction in porosities can be determined by observing the surface of the diffusing layer under an optical microscope at a magnification of 600 times. The porosities are visible by contrast and can be counted for example by digital processing.

Practically to measure the coverage rate, optical observations are made of the surface of the diffusing layer under an optical microscope and the total surface occupied by the porosities (sum of the surfaces occupied by each of the porosities) is determined - porosities visible from above because the matrix is transparent. We determined a surface rather than a volume occupied by the porosities for simplicity. To determine the total surface occupied by the porosities, a reference surface of 0.25 m ^{2 is} preferably chosen (in the plane of the glazing). Several images under an optical microscope may be necessary to form this reference surface taken in any region of the diffusing layer. The evaluation can be repeated in several regions distributed over the diffusing layer for an even more representative calculation of the coverage rate.

Preferably to guarantee the homogeneity of the optical properties of the diffusing layer, the porosity coverage rate is at most 20% and preferably at most 10% and better still at least 1%, rate measured in this reference surface taken from any region and better measured in a plurality of regions to cover at least 50% of the surface of the diffusing layer.

The porosities are preferably formed during cooking by elimination of organic compounds, for example from the medium used during the deposition, preferably by screen printing. The porosities are preferably not connected.

Regarding the porosities, preferably one or more of the following alternative or cumulative characteristics is provided:

these latter, in particular spherical or elliptical, are for example bubbles,

- In particular at least 60%, 70%, 80%, 90%, 95% (and even 100%) of the porosities are of width less than the thickness of the diffusing layer, in particular with a form factor height / width of at most 5, 2

- at least 60%, 70%, 80%, 90%, 95% (and even 100%) of the porosities are closed

- at least 60%, 70%, 80%, 90%, 95% (and even 100%) of the porosities are closed and spaced from the interface with the first sheet of glass or any underlayment

- the surface of the diffusing layer is devoid of open porosities

the interface between the diffusing layer and the first main face of the first glass sheet or of any undercoat (preferably mineral and preferably of thickness at most 1 μm, even 0.2 μm) is devoid of porosities

- in particular for at least 80%, 90% (and even 100%) of the porosities, the porosities (closed) are spaced at least 1pm, 2pm, 3pm the interface between the diffusing layer and the first main face of the first sheet of glass or of a possible undercoat (mineral preferably and preferably of thickness of at most 1pm, even 0.2pm) on the first main face

- at least 60%, 70%, 80%, 90%, 95% (and even 100%) of the porosities have a characteristic dimension (notably equivalent diameter) allowing diffusion of visible light, in particular at least 0.8 μm , to reduce blurring

- in particular for at least 80%, 90% (and even 100%) of the porosities, the porosities have a diameter (in particular equivalent) D1 which is at most 10pm or 8pm or 6pm and / or the ratio E1 / D1 is lower at 1 and at least 0.4, 0.5, 0.6, or 0.7.

The porosities of too small diameter favor a diffusion on a wider angular range.

Preferably, the diffusing layer has sufficient mechanical strength to withstand the test made by a sclerometer. In particular the mechanical resistance (to scratching) is carried out according to ISO standard 1518-2: 2011 and the diffusing layer supports a spring tension of at least 10N and even at least 16N.

Preferably, said vitreous material (and even enamel) has a chemical composition according to at least one of the following characteristics (preferably cumulative):

- the content by weight of ZnO + B ₂ O ₃ + Bi ₂ O ₃ + SiO2 + Na ₂ O is at least 80%, 90% or 95% of the total weight of the vitreous material (enamel) and even the weight content

ZnO + B ₂ O ₃ + SiO ₂ + Na ₂ O is at least 80%, 90% or 95% of the total weight of the vitreous material (enamel),

- the content by weight of ZnO + B ₂ O ₃ + Bi ₂ O ₃ is at least 30%, 40%, 50%, 60%, or 70% of the total weight of the vitreous material (enamel) and even the content by weight of ZnO + B ₂ O ₃ is at least 30%, 40%, 50%, 60%, or 70%, of the total weight of the vitreous material (of the enamel)

- the content by weight of zinc oxide ZnO is at least 15%, or 30% of the total weight of the vitreous material (enamel)

the content by weight of zinc oxide ZnO is the highest of the weight contents of the composition, or the second weight content.

It is also preferable to avoid (or content by weight of less than 1% of the total weight of the enamel) the transition metal oxides of column 5 to 11 and even 12 - except zinc - of the periodic classification of the elements. We prefer to avoid lead oxide, cadmium, mercury.

The total content of alkaline oxides other than Na ₂ O (such as Li ₂ O, K ₂ O) is preferably at most 3% by weight of the vitreous material (and even of the enamel), in particular 2% and even 1 % or 0.5%. In one case, the only alkaline oxide present is advantageously Na ₂ O.

We can limit to 5% 2%, 1% or 0.5% by weight of the vitreous material (and even of the enamel), the weight content of cumulative alkaline earth metal oxides Mg, Ca, or even Mg, Ca and Ba .

In addition, in a first embodiment, cumulatively:

- the content by weight of zinc oxide ZnO is the highest, at least 31% or 35% of the total weight of the vitreous material (enamel)

- the content by weight of boron oxide B ₂ O ₃ is at least 10%, 15% of the total weight of the vitreous material (of the enamel)

the content by weight of silica SiO ₂ is at least 5% of the total weight of the vitreous material (respectively of the enamel) and even at most 30%, 25%, 20%

- the Na ₂ O content by weight is at least 5 or 8% of the total weight of the vitreous material (of the enamel)

the content by weight of alumina AI ₂ O ₃ is at least 1% and preferably at most 8% or 6% of the total weight of the vitreous material (of the enamel) and the weight content of zirconia is at least 1% and preferably at most 8% or 5% of the total weight of the vitreous material (of the enamel),

the content by weight of MgO + CaO + SrO + BaO (+ K ₂ O) is at most 5% and preferably at most 2% of the total weight of the vitreous material (of the enamel)

the content by weight of lead oxide PbO is at most 0.5% of the total weight of the vitreous material (respectively of the enamel) and better still is zero, and also the content by weight of cadmium oxide, of mercury or of chromium is zero.

And even the preferred chemical composition to minimize blurring can include (or consist of) the following constituents, varying within the weight limits (by weight of the vitreous material (and even the enamel)) defined below: ZnO 31-55%

B ₂ O ₃ 15-30%

SiO ₂ 5-20% and even 10-20%

Na ₂ O + 5-15% with ZnO + B ₂ O ₃ + SiO ₂ + Na ₂ O> 80% or 90% and preferably

AI ₂ O ₃ 1-5%

ZrO ₂ 1-5%

Bi ₂ O ₃ 0-10% and even 0-2%

TiO ₂ 0-10%

And even:

K ₂ O 0-8% and even 0-2%

SrO 0-8% and even 0-2%

In particular, this composition does not contain lead, mercury (and from column 5 to 11) or even other constituents or less than 1% by weight or of impurities or less than 0.3% by weight.

In a second embodiment, cumulatively:

- the content by weight of silica SiO ₂ is the highest, at least 31, 35% or 40% of the total weight of the vitreous material (enamel)

- the ZnO content by weight is at least 5%, 15% of the total weight of the vitreous material (respectively of the enamel) and even at most 30%,

- the content by weight of boron oxide B ₂ O ₃ is at least 8%, of the total weight of the vitreous material (of the enamel)

- the Na ₂ O content by weight is at least 5 or 8% of the total weight of the vitreous material (of the enamel)

- optionally the alumina AI ₂ O ₃ content by weight is at least 0.5% or 1% and preferably at most 8% or 6% of the total weight of the vitreous material (of the enamel) and - the weight content of MgO + CaO + SrO + BaO + K2O is at most 5% and preferably at most 4% (of the total weight of the vitreous material (of the enamel)

the content by weight of lead oxide PbO is at most 0.5% of the total weight of the vitreous material (respectively of the enamel) and better still is zero, and also the content by weight of cadmium oxide, of mercury or in chrome is zero.

And even the preferred chemical composition for chemical resistance can comprise (or consist of) the following constituents, varying within the weight limits (by weight of the vitreous material (and even of the enamel)) defined below:

SiO ₂ 31-60% and even 40% -60% ZnO 15-30% B ₂ O ₃ 8-20% and even 8-15% Na ₂ O 5-20% and even 8-18%

with SiO ₂ + ZnO + B ₂ O ₃ + Na ₂ O> 80% or 90% preferably

AI ₂ O ₃ 0.5-5% ZrO ₂ 0-5% Bi ₂ O ₃ 0-10% and even 0-2% TiO ₂ And even: 0-12% and even 0-10% K ₂ O 0-8% and even 0-4% SrO 0-8% and even 0-4%

In particular, this composition does not contain lead, mercury (and from column 5 to 11) or even other constituents or less than 1% by weight or of impurities or less than 0.3% by weight.

Preferably, concerning the constitution of the diffusing layer, one or more of the following alternative or cumulative characteristics is provided:

- the content by weight of diffusing (solid) particles is preferably at most 1% of the total weight of the enamel, in particular 0.5% and even 0.1%, or even zero

- And / or the pigment content by weight is preferably at most 1% of the total weight of the enamel, in particular 0.5% and even 0.1%, or even zero

more generally, the content by weight of particles (in particular unfounded, crystals, pigments, and which may be diffusing particles, etc.) is preferably at most 1% of the total weight of the enamel, in particular 0.5% and even 0.1% or even zero

- the diffusing layer is colorless, in particular the total weight content of coloring elements (Fe ₂ O ₃ , CuO, CoO, Cr ₂ O ₃ , MnO ₂ , Se, Ag, Cu, Au, Nd ₂ O ₃ , Er ₂ O ₃ ) is at most 0.5% and even 0.1% of the total weight of the vitreous material and even of the enamel and preferably zero (except unavoidable impurities)

- the weight content of the glassy material is at least 80%, 90%, 95% and even 100% of the total weight of the enamel

- the enamel has a weight content of impurities of not more than 0.5% of the total weight of the enamel

- the diffusing layer (enamel) consists of the porous vitreous matrix and the porosities.

For each of the abovementioned oxides or groups of oxides, each of the lower limits can be combined with each of the upper limits, all the possible ranges not being mentioned here for the sake of brevity. Likewise, each range for a given oxide can be combined with any other range for the other oxides. Here again, not all combinations can be indicated so as not to unnecessarily burden the present text.

Preferably, the glassy material has a coefficient of thermal expansion and a glass transition temperature adapted to those of the glass sheet, and a low ability to devitrification.

The vitreous materials are generally obtained by a process in which a glass frit (of the same chemical composition as the vitreous material) and a typically organic medium are mixed to form a paste, which is deposited on the glass sheet before the cook.

The glass transition temperature Tg1 of the glass frit is low enough to be able to bake at temperatures at which the glass sheet cannot deform. At the same time, the frit must not crystallize (devitrify) during cooking, which would have the effect of generating too much roughness as well as high optical absorption.

Advantageously, the glassy material (very fusible) has a glass transition temperature Tg lower than that of the first glass sheet, in particular less than 590 ° C.

The glass transition temperature is measured by differential scanning calorimetry (also called DSC - for Differential Scanning Calorimetry), under nitrogen, with a temperature rise rate of 10 ° C / minute. We consider here the beginning of the curve (“onset temperature”) for the determination of the Tg.

The coefficient of linear thermal expansion can also be adapted to that of the glass sheet, generally being close to the latter, or slightly lower, in order to avoid during cooling the appearance in the vitreous material of mechanical stresses liable to to damage.

The coefficient of linear thermal expansion CT1 between 20 and 300 ° C of the glass constituting the vitreous material is preferably within a range from 70 to 100.10 ' ⁷ / ° C, in particular 70 to 90.10' ⁷ / ° C. In particular, the first glass sheet has a coefficient of linear thermal expansion CTO between 20 and 300 ° C tq CT0CT1 is positive and is at most 10.10 ' ⁷ / ° C.

The thickness of the first glass sheet is preferably within a range from 0.1 to 6 mm, in particular from 0.3 or 0.7 mm to 6 mm. The first sheet of glass can be with rectangular, square or even other main faces (round, oval, polygonal).

The glass sheet can be of any size, in particular greater than 1.5 m ² .

For the glass of the first glass sheet, it is preferably a glass of the soda-lime-silica type. The glass of the first glass sheet (and even of the glass sheet (s), if any) is preferably of the float type, that is to say capable of having been obtained by a process consisting in pouring the molten glass on a bath of molten tin (“float” bath). In this case, the diffusing layer can be deposited on the “tin” side as well as on the “atmosphere” side of the substrate. The term “atmosphere” and “tin” faces is understood to mean the faces of the substrate having been respectively in contact with the atmosphere prevailing in the float bath and in contact with the molten tin. The tin side contains a small surface quantity of tin having diffused in the structure of the glass.

The first sheet of glass is preferably colorless, and has a light transmission factor of at least 85%, or even 90% preferably within the meaning of standard EN 410: 1998.

The first sheet of glass is preferably colorless, can be a clear glass (of light transmission T _L greater than or equal to 90% for a thickness of 4 mm), is for example a glass of standard soda-lime composition such as Planilux® from the company Saint -Gobain Glass, or extra-clear (T _L greater than or equal to 91.5% for a thickness of 4 mm), for example a soda-lime-silica glass with less than 0.05% of Fe III or Fe ₂ O ₃ Diamant® glass from Saint-Gobain Glass, or Optiwhite® from Pilkington, or B270® from Schott, or other composition described in document WO04 / 025334. You can also choose Planiclear® glass from Saint-Gobain Glass

We can provide other characteristics for the first glass sheet:

the first sheet of glass is tempered, in particular thermal tempering (after baking in a quenching furnace, rapid cooling by nozzles typically), baking in the quenching furnace can be used to form the enamel layer from a composition liquid (paste) - possibly with drying before - based on glass frit

- The first glass sheet is curved and / or toughened.

The first sheet of glass (and even the second sheet of glass) is preferably curved and even thermally toughened. A heat treatment is preferred at a temperature greater than or equal to 450 ° C., preferably greater than or equal to 600 ° C.

Of course, in a most conventional configuration, the monolithic or laminated enameled substrate is not completely opaque (or reflective) so that an object can be seen behind the diffusing layer.

However, one may want a diffusing layer invisible in the extinct state and masked by on an opaque additional sheet or with an opaque layer, the light being visible from only one side.

For a roof (often tinted), a non-zero TL light transmission is preferred and even at least 0.5% or at least 2% and at most 40% and even at most 8%.

In particular, the automotive laminated glass roof meets current automotive specifications, in particular for light transmission T _L and / or energy transmission T _E and / or energy reflection R _E and / or for the total transmission of solar energy TTS .

For a car roof, we prefer one or more of the following criteria:

- T _E of at most 10% and even from 4 to 6%,

- R _e (preferably on the F1 side) of at most 10%, better from 4 to 5%

-and TTS <30% and even <26%, even from 20 to 23%.

For rear side glazing (laminated or not, including quarter panel) or rear window (preferably laminated glass module), a non-zero TL light transmission is preferred and even at least 10% or at least 20% and particular at most 80% or at most 70% (in particular rear side glazing or tinted bezel).

For front side glazing (laminated or not, in particular tinted), a non-zero TL light transmission is preferred and even at least 50% or at least 70%.

For a windshield (laminated preferably), a non-zero TL light transmission of at least 70% is preferred. These TL values can be in an area with the diffusing layer and / or adjacent to the diffusing layer (and in the clear of glass).

The diffusing layer can comprise or consist of a solid enamel, therefore a solid layer, with preferably a diffusing surface S defined by a length (the largest dimension) at least centimeter and even 3 or 5cm and the width ( the smallest dimension) to the normal length of at least 0.3mm and even 1cm. The flat can have any type of shape (geometric etc) and form a reference or a pictogram (full or almost full). It can be a line or even several lines of at least 0.3mm in particular peripheral along a edge (lateral or longitudinal), of two adjacent edges, or forming a frame (periphery of the glazing: roof, lateral etc).

The diffusing layer may comprise or consist of at least one (first) pattern M comprising a (first) set of disjoint and discrete diffusing elements (identical or not) in particular subcentimetric (in particular at least 0.3 mm) which covers a (first) Z zone.

The term “discrete diffusing element” is understood to mean an element separated from another element at least by a portion of the surface of the first glass sheet not provided with an element. The elements have diffusion properties different from those of the other surface parts of the first sheet of glass which surround them.

The discrete diffusing elements can have varied, symmetrical or asymmetrical shapes. The distribution of the discrete diffusing elements on the substrate can be periodic or aperiodic. Periodic distribution means that the discrete elements are placed on the first sheet of glass in an orderly fashion while an aperiodic distribution means that the discrete elements are placed on the first glass sheet in a random manner. The patterns can include arrays of discs and / or bands and / or sub-patterns, for example formed by a set of segments.

According to the invention, the term "pattern" means a shape defined on a part of the surface of the substrate comprising a set of discrete diffusing elements corresponding to a zone Z resulting from the juxtaposition of a set of discrete diffusing elements and parts of the first glass sheet separating said discrete elements. Zone Z is the smallest area that includes all of the discrete elements in a set. A pattern covering an area Z therefore comprises two parts. Part of the surface of the pattern includes the discrete elements and therefore has special diffusing properties.

The patterns can have any shape and be more or less large. The patterns can cover all or part of the surface of the first sheet of glass. When the pattern corresponds to a part of the surface of the first glass sheet, this part may preferably represent a few cm ² to several m ² .

The first pattern can therefore be a set of solid elements (discrete, punctual) in particular subcentimetric (in particular at least 0.3 mm) and / or forming straight and / or curved segments in particular of subcentimetric width and in particular of at least 0.3mm.

The diffusing elements are in particular:

- solid (geometric patterns like discs, squares, rectangle, ovals)

- or with at least one discontinuity, in particular based on one of straight and / or curved segments (bands), for example forming an open (C-shaped, etc.) or closed (in geometric form: annular, rectangular, triangular, etc.) outline ).

We can of course mix the type of diffusing elements (discs and segments etc).

The coverage rate of the diffusing elements depends on the targeted objective. Diffusing elements can cover at least 1%, 10%, 50%, of the area of zone Z covered by the pattern M.

Furthermore, the coverage rate of the discrete diffusing elements (solid etc.) can be variable, for example greater by moving away from the light source (to maintain the same luminance).

The size and / or spacing between discrete diffusing elements (solid etc) may vary.

It may be desirable for the diffusing layer (solid and / or pattern of discrete elements) to form a light mark, one or more light signals.

In the present application, the designation signaling is based on an iconic and / or linguistic semantics, that is to say using signs (numbers, pictograms, logos, symbolic colors ...) and / or a letter or words .

The diffusing layer can form a light signal, such as a pictogram, for example at least 2cm, 4cm in length and at least 0.3mm, 1 or 2cm in width.

One can form a luminous signaling banner (s):

- peripheral strip along a lateral or longitudinal edge, lower or upper

- central banner

- all around.

In one embodiment, during the measurement of blur, the light spot is centimetric at the level of the surface of the diffusing layer, in particular at most 5 cm, in particular approximately 2.6 cm, and in the zone illuminated by the spot la diffusing layer is full or is discontinuous (comprising all or part of said pattern) and preferably occupies at least 30%, 50%, 60% of the spot.

The transparency of the diffusing layer preserves the clear glass in the off state.

The diffusing layer (solid and / or pattern of discrete elements) extends on the first main face as a function of the targeted light surface.

It may be desired that the diffusing layer (in solid color and / or pattern of discrete elements), then called covering, extends over at least 50%, 70% or 80% or 90% of the first main face (in particular outside the area marginal for example less than 1cm from the edge of the first sheet of glass).

However, it may be desired that the diffusing layer (in solid color and / or pattern of discrete elements) - then local - extends over a region of the first main face for example does not extend over at most 50%, 40% or 30% or 20%, 10% 1%, 0.1% of the first side.

For example, the local diffusing layer is on the periphery of the first face.

The diffusing layer can cover less than 50% of the surface of the first sheet of glass when it is necessary to preserve a clear of glass in the lit state.

A peripheral strip can be formed along a lateral or longitudinal, lower or upper edge of the first glass sheet.

For a windshield, the pictogram (or pictograms) in particular may have one or more of the following functions:

- display of driving assistance information, in particular alert, obstacle detection,

- display of information (levels, operating condition, wear, etc.) on the characteristics of the vehicle (engine, wheels, brakes, headlights, etc.), in particular in the event of an alert (with a stop requested)

- display of information on the external environment: weather, distance from a petrol station (from an electricity point, etc.), from a city, from a motorway exit

- display of information on connectivity: access to the network (social network, internet, etc.)

- flashing repeater

- display of advertising information or for an availability taxi.

For a side window, the pictogram (or pictograms) in particular may have one or more of the following functions (cumulative):

- display of information on the external environment: weather, points of interest, traffic info.

- display of information on connectivity: access to the network (social network, internet, etc.)

- flashing repeater,

- Blind spot indicator,

- display of advertising information, LOGO (brand of the car manufacturer, etc.).

For a telescope, the pictogram in particular may have one or more of the following functions (cumulative):

- flashing repeater

- third brake light

- emergency triangle

- warning pictogram (compliance with safety distance etc).

You can form a light strip and even a light strip (s), in case of plurality each can be illuminated independently and with a different color or not. We can therefore provide several light sources, several colors.

In one embodiment, the surface of the diffusing layer may be a free surface (no other element (s) on it).

In another embodiment, the surface of the diffusing layer can be covered by (and in contact with) a transparent element preferably of thickness at most 1.5 mm or submillimetric, in particular a polymeric film in adhesive contact with the layer diffusing or an overlay (monolayer or multilayer). It can be a film glued with an optical glue on the first main face and in particular the enamelled substrate is a monolithic glazing (not part of a laminate or of multiple glazing.

The polymer film can be tinted and / or can carry a functional layer (electrically conductive, etc.). Alternatively the polymeric film (tinted, bearing a functional layer is glued to the second main face.

The polymeric film can be between 5 μm and 1 mm thick, preferably between 10 μm and 500 μm, in particular between 20 and 300 μm, preferably at least 50 μm and at most 200 μm.

The polymeric film can be chosen from a polyester, in particular a polyethylene terephthalate (PET), a polyethylene naphthalate (PEN), a polycarbonate (PC), a polyolefin such as a polyethylene (PE), a polypropylene (PP), a polyurethane, a polyamide, a polyimide or even a fluorinated polymer such as ethylene tetrafluoroethylene (ETFE), chlorotrifluoroethylene ethylene (ECTFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE) and fluorinated ethylene-propylene copolymers ( EFF).

PET is preferred for its transparency, its surface quality, its mechanical strength, its availability, at all sizes. The absorption of this transparent film, in particular of PET, is preferably less than 0.5% or even at most 0.2% and with a blurring of less than 1.5% and even at most 1%.

The optical adhesive is in particular (a resin) based on polyester, acrylic or silicone. It can be a pressure sensitive adhesive (PSA). A pressure sensitive adhesive, abbreviated PSA and commonly called self-adhesive, is an adhesive which forms a bond when pressure is applied to it so secure the adhesive to the surface to be bonded. No solvent, water, or heat is required to activate the adhesive.

PSAs are generally based on elastomer coupled with a suitable additional adhesive agent or "tackifier" agent (for example, an ester resin).

Elastomers can be based on:

- acrylates, which can be tacky enough not to require an additional tackifying agent

- nitriles

- silicone, requiring special tackifying agents such as “MQ” type silicate resins, composed of monofunctional trimethyl silane (M) which reacted with quadrifunctional silicon tetrachloride (PSA), for example silicone-based PSAs polydimethylsiloxane gums and resins dispersed in xylene or a mixture of xylene and toluene,

- block copolymers based on styrene such as block copolymers Styrene butadiene -styrene (SBS), Styrene-ethylene / butylene -styrene (SEBS), styreneethylene / propylene (SEP), Styrene isoprene -styrene (SIS),

- vinyl ethers.

The pressure-sensitive adhesive is for example chosen from PSAs based on acrylates and PSAs based on silicone. These adhesives are marketed as rolls of double-sided adhesives. Mention may be made, as silicone-based PSA, of the adhesives from Dow Corning® such as 2013 Adhesive, 7657 Adhesive, Q27735 Adhesive, Q2-7406 Adhesive, Q2-7566 Adhesive, 7355 Adhesive, 7358 Adhesive, 280A Adhesive, 282 Adhesive, 7651 Adhesive, 7652 Adhesive, 7356 Adhesive.

In one embodiment, the first sheet of glass is part of a laminated glazing (possibly curved) comprising:

- said first sheet, in particular colorless, made of clear or extra-clear glass

- a laminating interlayer, in particular colorless or even tinted

- and a second transparent sheet, preferably of glass (or a plastic such as poly (methyl methacrylate) or PMMA), in particular colorless, in clear or extra-clear glass or even tinted

The first main face is preferably the internal main face of the first sheet (for invisibility), on the laminating interlayer side, in particular the diffusing layer is in adhesive contact with the laminating interlayer or an overlayer is in adhesive contact with the laminating interlayer or the external face for process reasons.

Conventionally, the main faces of a laminated automotive glazing are numbered from 1 to 4:

the face F1 is the external (external) face of the preferably tinted external glass and

- the face F2 is the internal face (interlayer side of laminating) of the external glass

- the laminating interlayer is preferably PVB

- the face F3 is the internal face (interlayer side of laminating) of the interior glass preferably colorless often of thickness less than or equal to that of the exterior glass

- side F4 is the internal side (passenger compartment side) of the interior glass

The preferably internal glass, in particular thin glass with a thickness of less than 1.1 mm, can preferably be chemically toughened. We can cite the examples of applications WO2015 / 031594 or WO2015066201.

In a preferred embodiment (for a roof, a fixed lateral (quarter panel, etc.), a windshield, the first sheet of glass is the interior glazing and the exterior glass is tinted. The diffusing layer is therefore on the face F3 or F4. This can allow for example to make an internal signaling (masked or not by a layer opposite F3).

Opposite F3 there is a better off state rendering. The edges of the enamel are much less visible, probably because there is a difference in the enamel / interlayer index that is less favorable for refraction.

In an alternative embodiment (window, windshield), the following configuration can be provided:

- side F1 is the outer (outer) side of the colorless, slightly tinted outer glass

- the face F2 is the internal face (interlayer side of laminating) of the external glass

- the laminating interlayer is preferably PVB if necessary tinted (to compensate for the weak tint of the exterior glass,

- the face F3 is the internal face (interlayer side of laminating) of the interior glass, for example colorless

- face F4 is the internal face (passenger compartment side) of the interior glass.

Preferably in this alternative mode, the first sheet of glass may be the exterior glazing. The diffusing layer is therefore on the face F2 or even F1. This can, for example, allow external signaling (masked by a layer opposite F3).

Opposite F2 and we observe a better off state rendering. The edges of the enamel are much less visible, probably because there is a difference in the enamel / interlayer index that is less favorable for refraction.

We prefer to choose a lamination interlayer (clear or tinted) that is as blurry as possible, that is to say at most 1.5% and even at most 1%.

These spacers can be based on polymers chosen from polyvinyl vinyl (PVB), polyvinyl chloride (PVC), polyurethane (PU), polyethylene terephthalate or ethylene vinyl acetate (EVA). The spacers preferably have a thickness of between 100 μm and 2.1 mm, preferably between 0.3 and 1.1 mm.

The laminating interlayer can be made of polyvinyl butyral (PVB), polyurethane (PU), ethylene / vinyl acetate copolymer (EVA), formed from one or more films, for example having a thickness between 0.2 mm and 1.1mm.

The laminating interlayer may optionally be composite in its thickness (PVB / plastic film such as polyester, PET etc / PVB).

The surface of the laminating interlayer may be less than the surface of the laminated glazing, for example leaving a groove (in frame or strip), free and therefore not laminated.

You can choose a classic PVB like RC41 from Solutia or Eastman.

For a laminated windshield, the laminated interlayer may have a cross section decreasing in wedge shape from the top to the bottom of the laminated windshield, in particular to avoid a double image in the case of a head-up display ( HUD) additional.

The laminating interlayer may comprise at least one so-called central layer of viscoelastic plastic material with vibro-acoustic damping properties, in particular based on polyvinyl butyral (PVB) and of plasticizer, and the interlayer, and further comprising two outer layers in Standard PVB, the central layer being between the two outer layers. As an example of an acoustic sheet, mention may be made of patent EP0844075. Mention may be made of the acoustic PVBs described in patent applications WO2012 / 025685, WO2013 / 175101, in particular tinted as in WO2015079159.

One can use a PVB of acoustic variety, in particular of 0.81 mm of thickness marketed by the Company Eastman under the registered mark Saflex®, or of 0.51 mm of thickness marketed by the Company Sekisui under the registered mark SLEC® .

And even to use a head-up display device of the HUD type, possibly one or both of the external layers has a cross section decreasing in wedge shape from the top to the bottom of the laminated glazing, the layer of viscoelastic plastic material with properties vibro-acoustic damping having a constant cross section from the top to the bottom of the laminated glazing.

The glass of the first glass sheet can be neutral (without coloring). The glass of the second glass sheet can be (slightly) tinted in particular gray or green, such as TSA glass from the company Saint-Gobain Glass. The glass of the first and / or of the second glass sheet may have undergone a chemical or thermal treatment of the hardening, annealing or toughening type (in particular for better mechanical resistance) or may be semi-toughened.

For laminated vehicle glazing, in particular windshield or lateral glazing, the T _L may preferably be at least 70% and even at least 75% or 80%.

In one embodiment, the second glass sheet is made of organic glass (such as polycarbonate or PC, PMMA, cyclo-olefin copolymer (COC) or even polyethylene terephthalate (PET) possibly protected by a coating (opposite F4).

The second outer glass sheet can have functional thin layers on one or the other of its faces F1 and F2 or both: one can cite a hydrophobic or self-cleaning, photocatalytic layer on the F1 face.

Preferably the laminated glazing forms a windshield for a road vehicle such as an automobile, a truck, with the first and second curved glazing and even a PVB laminating interlayer. The bending of the first and of the second glass sheet (windshield) can be in one or more directions for example as described in document WO2010136702.

Laminated glazing, in particular a rectangular road vehicle windshield, can be:

- of width (horizontal dimension) Lp of at least 1200mm and at most 1850mm and preferably from 1350 to 1550mm.

- of height (vertical dimension) Hp of at least 800mm and at most 1400mm and preferably from 950 to 1050mm.

The second glass sheet can be tinted for example with Venus®, TSA3 + or TSA4 + glass also sold by the Applicant. The second sheet typically has a thickness of between 1.4 and 2.1 mm. Table A below gives more details of examples of glass sold by the Applicant. SGS THERMOCONTROL ® Absorbing / Venus glass improves thermal comfort by absorbing the energy load in the mass of the glass. These glasses are divided into two categories: "Vision" (Light transmission> 70%) and "Privacy" (Light transmission <70%).

Glass type TL (%) TE (%) RE (%) SGS THERMOCONTROL® Venus Green 55 49 27 7 High Performance green tinted H Clear Glass 8 16 3 SGS THERMOCONTROL® Venus Green 35 5 22 5 SGS THERMOCONTROL® Venus Gray 10 0 8 1 SGS THERMOCONTROL® Absorbing TSA3 + 1 44 18 Standard green glass 8 53 25

Table A

“Vision” glass is suitable for all types of glazing in the vehicle: green / blue / gray and ensures reduced energy transmission (TE). The most popular color 5 for this purpose is green. It was chosen because of its neutral appearance which does not affect the color harmony of a vehicle. "Privacy" glass is mass-tinted glazing for thermal comfort and privacy. It is a dark green or dark gray tinted glazing. To ensure privacy, this glazing has light transmission values that are below 70%, generally around 55% or less. In most countries, Venus / Privacy glass is suitable for rear side windows (after pillar B), rear window and roof. SGS THERMOCONTROL ® Venus consists of dark gray or dark green tinted glazing. They have all the thermal advantages of “Vision” type glass (SGS THERMOCONTROL ® Type) with improved sun protection

The second sheet can have a larger size than the first, thus exceeding the latter on at least part of its periphery in particular when the first sheet is lit by its peripheral edge, the light source like the LED modules can then rely on the F2 side of the second sheet, where it exceeds the first sheet.

As an example of glazing which is offset or not, with glazing lit by the edge, mention may be made of patent applications WO2010 / 049638, WO2013079832, WO2013153303.

In particular in the case of a tinted laminating interlayer and / or of a second sheet tinted in particular with glass, an optical isolator can be provided on the first main face with a refractive index of less than n1, in particular a layer of porous silica (sol-gel) with a refractive index of at most 1.3 even of at most 1.2 and better of thickness of at least 200nm even of at least 400nm and preferably of at most 1pm. This layer of porous sol-gel silica is described in application W02008 / 059170 in particular in FIG. 11 or even in application W02015 / 101745.

The porous silica layer is discontinuous and the diffusing layer according to the invention is in the discontinuity (s) (on and in contact with the first face).

Alternatively, the porous silica layer can be on either side of the diffusing layer or even just in the area upstream between the edge of coupling with a light source and the edge of the nearest diffusing layer.

In a preferred embodiment, -with a light source (preferably diodes on PCB support) is optically coupled to the first glass sheet-, the glazing is laminated comprising the first glass sheet, made of mineral glass (clear or extra-clear ) in particular with a thickness of at most 2.1 mm, a lamination interlayer made of polymeric material, preferably thermoplastic (better made of PVB) and a second glass sheet, made of mineral glass, in particular of thickness of at most 3 mm, and is chosen in particular from:

- a roof (for a light function inside the vehicle) with the first innermost glass sheet, the diffusing layer is preferably on the face F3 in particular in contact with the lamination interlayer (a transparent overlayer which can be inserted preferably at most 1pm thick), the second sheet of glass and / or the lamination interlayer being preferably tinted

- a windshield (for a light function, for example for signaling the driver inside the vehicle, as an anti-collision means) with the first innermost glass sheet, the diffusing layer is preferably on the face F3, the second sheet glass and / or the laminating interlayer preferably being tinted,

- Or a side window or a rear door window or a rear window (for a light function in particular for vehicle signaling outside) with the first outermost glass sheet, the diffusing layer is preferably on the face F2.

It is possible to place an opaque or reflective element (masking decoration, etc.) offset or facing the diffusing layer, in particular on a second transparent sheet.

The first glass sheet may have a masking layer which is often peripheral on the first or second face, for example an opaque black or dark enamel layer forming a peripheral strip or even a peripheral frame.

The diffusing layer can be more central, offset from the masking layer

The first glass sheet may in particular comprise a masking layer, in particular in enamel, adjacent to the diffusing layer or on the second face offset from the diffusing layer, in particular peripheral masking layer along the optical coupling wafer with a source. light

Preferably at least in the guide zone, the width of this layer along the optical coupling edge (between the edge and the edge of the diffusing layer) is eliminated or limited to less than 5 cm or even 3 cm.

The light source can be placed in a hole at the level of the peripheral masking or a more central hole, as detailed later.

In the case of laminated glazing, to hide from the exterior of the vehicle some of the elements, it is known to provide the inner face of the outer glass sheet (face F2) with black enamel. Equivalently, to hide some of the aforementioned elements from the inside or even from the outside of the vehicle, it is advantageous to provide the inner face of the inner glass sheet (face F4 with laminated glazing) of enamel. black.

Printing is generally carried out in particular by screen printing on the flat substrate (that is to say before bending), and the face opposite to that on which one is printing (for example here the face F3) is generally placed on a support such as conveyor belt.

Wider :

- the interior glazing (often the first sheet of glass) may have a peripheral interior masking layer (may be a layer of black or dark enamel, a layer of paint or an opaque ink preferably on the F2 side or on the laminating interlayer or even on an additional carrier film (PET etc).

- And / or the external glazing (sometimes the first sheet of glass) may have a peripheral external masking layer (respectively external masking layer) which is a layer of black or dark enamel, a layer of paint or an opaque ink of preferably on the face F2 (respectively F3 or F4) or on the lamination interlayer or even on an additional carrier film (PET etc).

Advantageously, the interior and exterior masking layers are made of the same material, preferably in particular black enamel, or in F2 and F4 or in F2 and F3.

The diffusing layer can be opposite F3:

- in a saving of the interior masking layer on face F3 or face F4

- opposite the exterior masking layer opposite F2.

In the alternative embodiment (colorless exterior glass, for example bezel) the diffusing layer may be opposite F2:

- in a saving of the exterior masking layer opposite F2

- and even opposite the interior masking layer opposite F3 or F4.

The first main face can be the internal face called face F3 and the second glass sheet comprises a peripheral masking layer (for example in F4) in particular in enamel with a saving in line with the diffusing layer.

The first glass sheet may comprise under the diffusing layer and / or on a second main face opposite to the first main face with the diffusing enamel layer and / or on the first face under the diffusing layer and / or adjacent to the layer diffusing, a transparent functional layer - as long as this layer does not significantly harm the light guide function (by its absorption, etc.) -. Naturally, the light transmission factor of the functional layer / first glass sheet / diffusing layer assembly can be lowered by the addition of this layer.

It is important as a priority that the blur remains low (and the sharpness preferably high) preferably at most 15%.

There are several types of functional layers chosen from at least one of the following layers:

a layer of silica, in particular porous and for example sol gel, for example as described in application WO2008 / 059170

- an optical isolating layer, for example a porous silica layer and the diffusing layer is opposite, for example

a masking layer adjacent to the diffusing layer, in particular peripheral layer, in particular an enamel layer, preferably of width less than 5 cm or 3 cm between the optical coupling wafer and the edge of the nearest diffusing layer

- an electrically conductive layer, in particular an electrode (electrically conductive layer connected to an energy supply), a layer (forming a circuit) of electric supply of (opto) electronic components (sensors etc.) - if possible the most transparent components and / or discrete possible-, in particular a transparent conductive oxide layer,

- an electromagnetic shielding layer

- a heating layer, that is to say an electrically conductive layer supplied electrically (typically by two current supply strips), in particular with a heating zone which is connected to at least two electrically conductive bus bars (width of the busbars is preferably 2 mm to 30 mm, 4 mm to 20 mm and in particular 10 mm to 20 mm) intended for connection to a voltage source such that a current path for a heating current is formed between them

a layer reflecting or absorbing solar radiation, called a solar control (and /) or low emissivity layer, in particular a coating comprising (at least) a functional layer of transparent conductive oxide (TCO) or (at least) a layer metallic functional, a solar control layer that can also serve as a heating layer with a current supply at the periphery;

The functional layer (electroconductive, etc.) can cover at least 50% and even at least 70% or 80% or at least 90% of the main face.

The electroconductive layer is a layer (monolayer or multilayer, therefore stacking), preferably with a total thickness less than or equal to 2 μm, particularly preferably less than or equal to 1 μm.

The electrically conductive layer may have a resistance of 0.4 ohm / square to 10 ohms / square of sheet and even of 0.5 ohm / square to 1 ohm / square, with typically on-board voltages from 12 V to 48 V or, in the case of electric vehicles, with typical on-board voltages up to 500 V.

For laminated glazing, you can combine layers on the side F2 and F3 or F2 and F4. The electroconductive layer on the face F3 is for example a stack sold by the Applicant Company under the name of Climacoat.

A functional layer can be deposited by various techniques for depositing thin layers, such as for example the sputtering technique, in particular assisted by magnetic field (magnetron process), chemical vapor deposition (CVD), in particular assisted by plasma ( PECVD, APPECVD), or else by liquid deposition, in particular by screen printing, printing or by sol-gel.

The electrically conductive layer can include transparent conductive oxides (TCO), i.e. materials which are both good conductive and transparent in the visible, such as indium oxide doped with tin (ITO). ), tin oxide doped with antimony or fluorine (SnO ₂ : F) or zinc oxide doped with aluminum (ZnO: Al). An ITO-based electrically conductive layer has, for example, a surface resistance of 50 to 200 ohms per square.

These electroconductive layers based on conductive oxides are preferably deposited on thicknesses of the order of 50 to 100 nm.

The TCO layer (of a transparent electrically conductive oxide) is preferably a fluorine doped tin oxide layer (SnO ₂ : F) or a mixed tin and indium oxide layer (ITO). .

Other layers are possible, among which the thin layers based on mixed indium and zinc oxides (called "IZO"), based on zinc oxide doped with gallium or aluminum, based on titanium oxide doped with niobium, based on cadmium or zinc stannate, based on tin oxide doped with antimony. In the case of zinc oxide doped with aluminum, the doping rate (that is to say the weight of aluminum oxide relative to the total weight) is preferably less than 3%. In the case of gallium, the doping rate can be higher, typically in a range from 5 to 6%.

In the case of ΙΊΤΟ, the atomic percentage of Sn is preferably within a range ranging from 5 to 70%, in particular from 10 to 60%. For layers based on tin oxide doped with fluorine, the atomic percentage of fluorine is preferably at most 5%, generally from 1 to 2%.

By “emissivity” is meant the normal emissivity at 283 K within the meaning of standard EN 12898. The thickness of the low emissivity layer (TCO etc.) is adjusted, as a function of the nature of the layer, so as to obtain the desired emissivity, which depends on the desired thermal performance. The emissivity of the low emissivity layer is for example less than or equal to 0.3, in particular to 0.25 or even to 0.2. For ITO layers, the thickness will generally be at least 40 nm, or even at least 50 nm and even at least 70 nm, and often at most 150 nm or at most 200 nm. For layers of fluorine-doped tin oxide, the thickness will generally be at least 120 nm, or even at least 200 nm, and often at most 500 nm.

For example, the low emissivity layer comprises the following sequence: high index sublayer / low index sublayer / a TCO layer / optional dielectric overlay.

As a preferred example of a low emissivity layer (protected during quenching, one can choose a high index sublayer (<40 nm) / low index sublayer (<30 nm) / an ITO layer / high index overlayer (5-15 nm )) / low index overlay (<90 nm) barrier / last layer (<10 nm).

In a preferred embodiment in the case of laminated glazing (glazed roof, etc.):

- the first and / or second glazing is tinted and / or the lamination interlayer is tinted over all of its thickness

- the face F4 is coated with a layer of transparent electrically conductive oxide (called TCO), in particular a stack of thin layers with TCO layer

- And / or preferably the face F2 or F3 is coated with a stack of thin layers with layer (s) of silver.

Mention may be made, as low-emissivity layer based on TCO, of those described in patent US2015 / 0146286, on the face F4, in particular in Examples 1 to 3.

The electroconductive layer can also be a metallic layer, preferably a thin layer or a stack of thin layers, called TOC (for “Transparent conductive coating” in English) for example in Ag, Al, Pd, Ou, Pt In, Mo, At and typically of thickness between 2 and 50 nm.

For the electrode or heating function, a printed busbar preferably contains at least one metal, a metal alloy, a metallic and / or carbon compound, in particular preferably a noble metal and, in particular, silver. The printing paste preferably contains metallic particles, metallic and / or carbon particles and, in particular particles of noble metal such as silver particles. The thickness of a printed bus bar may preferably be from 5 pm to 40 pm, more preferably from 8 pm to 20 pm and more particularly preferably from 8 pm to 12 pm.

Alternatively, however, a bus bar may also be in the form of a strip of an electrically conductive sheet. The busbar then contains, for example, at least aluminum, copper, tinned copper, gold, silver, zinc, tungsten and / or tin or alloys thereof. The strip preferably has a thickness of 10 pm to 500 pm, particularly preferably from 30 pm to 300 pm.

Instead of being on one of the first sheet and / or of the optional second glass sheet, the layers described above (electrically conductive, solar control, heating, electrode) may be on a support, preferably transparent polymer (polyterephthalate). ethylene called PET etc) within the laminating interlayer for laminated glazing.

One can use for example a clear film of PET coated with an electrically conductive layer, for example clear film of PET called XIR from the company Eastman, a film coextruded in P ET-P MM A, for example of the SRF 3M® type (SRF for Solar Reflecting Film), but also many other films (for example in PC, polyester, PEN, PMMA, PVC) etc.

Laminated glazing used for the automobile, in particular as a motor vehicle windshield, is capable of carrying many functions (in addition to the above-mentioned heating layers for defrosting / demisting, solar control), layers and numerous accessories, among which one can to quote :

- a base or support for an interior mirror or stereoscopic cameras,

- one or more sensors (a rain detector, etc.)

- heating wires, in particular a thickness less than or equal to 0.1 mm, preferably of copper, tungsten, gold, silver or aluminum or alloys of at least two of these metals

- an electrically controllable device within the laminating interlayer - between two sheets of laminating interlayer (EVA or PVB) - chosen from at least one of the following devices as desired, offset or facing the diffusing layer:

- (to preserve privacy) a liquid crystal device, with a layer of liquid crystals between two electrodes for example as described in patent applications CN102785555A, EP 964288

- (for a clear to obscure passage): an optical valve device (SPD for suspended particle device in English)

- (for a variable shade) an electrochromic device,

- an additional light element: an organic diode (OLED).

a multipixel screen (liquid crystal, active matrix OLED, etc.) for example as described in patent application WO2017 / 115036.

The enamelled substrate can form:

- a laminated, curved roof, the first sheet of glass is the internal glazing

- a monolithic (colorless) or laminated, domed bezel, the first sheet of glass is the external glazing, the diffusing layer is on the passenger compartment side

- a side window (front or rear) monolithic (colorless with any tinted film added, for example glued) or laminated, curved, the first sheet of glass is internal or external glazing

- a laminated, curved windshield, the first sheet of glass is the internal or even external glazing.

The invention also relates to an automotive luminous glazed device comprising the enamelled substrate (monolithic, laminated glazing) described above and a light source which is optically coupled to the first sheet of glass, in particular to the edge or to a wall (internal edge) a hole (closed) in the first coupling glass sheet, direct optical coupling or by means of an optic, possibly a light source within said hole.

In particular the hole can be:

- blind or through through the thickness for example for a simple glazing

- in the case of laminated glazing, the hole can be through and limited by the lamination interlayer or the lamination interlayer can also be drilled and even the second glass sheet can be drilled (through hole or blind)

An element (optical guide, etc.) can be added between the light source and the wall of the hole or the edge.

The preferably through hole may have any geometric shape mainly limited by the technical feasibility of the drilling process and by the solidity of the pierced glass sheet, for example, circular or rectangular shapes, preferably with rounded angles,

The through hole or holes may preferably be large enough to accommodate several diodes or several diode modules or an intermediate coupling piece.

The extent of the hole (through) preferably does not exceed 100 cm ² , and is advantageously between 0.7 and 50 cm ² .

In the case of laminated glazing, the through hole can be limited to the first sheet, or it can extend through the laminating interlayer and the second transparent sheet. In this case, the drilling is preferably carried out on the glazing after laminating.

In the case where the hole extends through the entire thickness of the glazing, the through hole in the second sheet is advantageously filled with an obstruction element.

Reference may be made to the examples of holes and of light source such as those described in patent WO2013 / 110885 or WO2014 / 131972.

The distance separating the wall (internal edge) from the hole of the diffusing layer is preferably at most equal to 50 cm or even 20 cm, in particular at most equal to 10 cm, and ideally at most equal to 5 cm. This distance is that between the wall and the edge of the diffusing layer closest to this wall.

The light source, in particular LEDs, can be between the edge of the laminated glazing, and a peripheral polymeric encapsulation as described in application WO2010049638 in particular in FIG. 15 or in FIG. 16. The encapsulation can be made of polyurethane, in particular PU -RIM (reaction in mold in English), the crosslinking of the two-component PU operating in the mold, once the two components are injected simultaneously. This material is typically injected up to 130 ° C and a few tens of bars.

The polymeric encapsulation may include a recess to remove the light source.

The light source preferably comprises a plurality of inorganic light emitting diodes even if it is possible to envisage another type such as for example a light strip (OLED etc.).

The automotive light glazing device according to the invention is preferably used as a source of polychromatic lighting, in particular white light.

The diodes may or may not be integral with the glass;

The diodes may or may not be mono or polychrome and be concealed.

The diodes can be simple semiconductor chips (without encapsulation or collimation lens), of size for example of the order of a hundred pm or of one or a few millimeters (for example 1mm in width, 2.8mm in length and 1.5 mm in height). They may also include a protective envelope, temporary or not, to protect the chip during handling or to improve the compatibility between the materials of the chip and other materials and / or be encapsulated (for example encapsulation of low volume of type ' SMD '(“surface monted device”), with an envelope, for example of epoxy or nylon type resin, encapsulating the chip and having various functions: protection against oxidation and humidity, diffusing, focusing, or collimation role , wavelength conversion ...).

The total number of diodes is defined by the size and location of the areas to be lit, by the desired light intensity and the required uniformity of light.

The diodes can be (pre) assembled on one or more PCB supports (PCB for Printed Circuit Board in English) or supports with power supply tracks, PCB supports can be fixed to other supports (profiles, etc.) .

The diodes may comprise or even preferably be simple semiconductor chips, for example of width WO of the order of a hundred μm or from 1 to 5 mm. The width of each diode of the light source is preferably less than the thickness of the first sheet of glass.

Each diode of the light source can be chosen in particular from at least one of the following light-emitting diodes:

- a diode with lateral emission, that is to say parallel to the (faces of) electrical contacts, with an emitting face lateral with respect to the PCB support,

- a diode, the main emission direction of which is perpendicular or oblique to the emitting face of the chip.

The emission diagram of a conventionally Lambertian diode with a half emission angle of 60 °.

A light source can be provided on one side, two sides (opposite or adjacent) or even on three or four sides of the first sheet of glass.

In an advantageous embodiment, one or more sensors linked to the environment and / or to the glazing may be associated with the light sources and / or with the power supply system for said glazing. One can use for example a luminosity detector (photodiode, etc.), a temperature sensor (external or integrated, on the glass or the light sources), the used sensor controlling for example the feeding of the light sources via a computer or central unit. You can define a measurement value of the sensor (maximum brightness for example) beyond which the glazing stops performing one of its functions (extraction of light or activation of light sources in particular). For a higher value, for example, the glazing power supply is blocked and for a lower value, the glazing or one of its functions (for example its brightness level) can be controlled via the information received from or s) sensors. The glazing function can also be "forced" by the user by deactivating the sensors.

The sensors can be inside (e.g. the vehicle) or outside. The management of the glazing according to the external environment makes it possible for example to improve the durability of the light sources and other components (polymers, electronic components, etc.), limiting their operation under conditions of light and / or temperature. in particular making it possible to significantly reduce (between 10 and 20 ° C minimum) the maximum temperatures to which light sources can be exposed during the use of the product, while retaining the functions of luminous glazing. This coupling also makes it possible to automatically adapt the lighting intensity of the glazing to the external light conditions, without the user having to intervene.

The invention also relates to a motor vehicle incorporating the automobile luminous glazed device defined above.

The diffusing layer comprising a glassy material is preferably obtained by a process in which:

- a glass frit is mixed with an organic medium so as to form a paste,

- said paste is deposited on the first glass sheet,

- we cook the whole thing.

The deposition of the dough can be carried out preferably by screen printing, or by ink jet, by digital printing, by dipping, by application with a knife, by spraying, by spinning, by vertical coating or even using a slot die coating.

Thus, the invention also relates to the method of manufacturing the enamelled substrate described above which includes the formation of a diffusing layer involving in this order:

- depositing on the first sheet of calcium silicate glass preferably by screen printing of a liquid composition (paste of suitable viscosity) with a wet thickness of at least 10 μm and at most 40 μm, and better still from 15 to 30 μm comprising a frit of glass and an organic medium, in particular water-soluble,

- preferably drying (in particular by infrared or even ultraviolet) at a temperature of at most 200 ° C or 150 ° C and preferably between 100 ° or 110 ° C and 130 ° C

- cooking at a temperature Te (above Tg1 between at least 40 ° C in particular) between 630 ° C and 720 ° C, in particular from 120s to 650s.

The temperature is controlled (not too high) in order to trap enough closed porosities.

Drying eliminates the vast majority of the solvent (at least 80% for example) by limiting the risks of pollution of the surface by dust which would impact the transparency of the diffusing layer

The temperature and the duration can preferably also be fixed in order to be part of a quenching (thermal) or bending (hot) quenching process.

The temperature and the duration preferably can preferably also be fixed to be part of a lamination process.

The first sheet of glass that is part of a laminate can be cold curved for flexibility (its thinness) and the second sheet of glass is thicker.

In particular, these temperatures in an oven are preferred during a bending operation and / or a thermal quenching (before or without bending) following baking.

In particular the oven can be in an industrial heating (bending) quenching line. The quenching does not modify the optical characteristics of the diffusing layer.

The bending is done:

- by gravity collapse, for example as described in patents WO2007138214, W02006072721, in particular the first and second glass sheets can be deposited in a bending furnace, stacked and in contact with one another, on a skeleton for bending by collapse gravity

- Or by suction for example as described in patent W002 / 064519.

In curved laminated glazing, the first sheet of glass is not necessarily thermally toughened and / or curved by heating when it is thin.

In particular, these times are compatible with the cooking time in a quenching or bending quenching heating line.

In particular, the following cooking cycle is chosen, with exclusive radiative heating:

- 640 ° C for 400sec, which is the cycle corresponds to the gravity collapse process (most often with the two paired glasses),

- temperature in a range from 680 ° C to 710 ° C for 180sec which is the cycle for thermal (semi) quenching;

Advantageously, the first glass sheet being conveyed on a conveyor with the first main face opposite the conveyor side, the baking is in an oven on the conveyor, bending oven if necessary, and is optionally the baking is followed by thermal tempering.

Conventionally, the lamination comprises evacuating - by any means of aspiration - heating and possible pressurization. We use an oven or autoclave.

Thus, the lamination may include degassing, sealing of the edge, and involves the implementation of temperatures and pressures appropriate in the usual way, during the autoclave, the sheet such as the PVB is brought to relatively high temperature (greater than 100 ° C for PVB often between 90 ° c and 140 ° C), which will soften it and allow it to creep. When using several sheets, in particular PVB, a remarkable phenomenon occurs then, the interfaces between the different PVBs will disappear, the PVB will somehow heal to form only a homogeneous and continuous film at the end of the autoclave.

Under the usual conditions for assembling laminated glazing, combining heating, placing under vacuum (vacuum) inside the laminated structure aims to evacuate the air present between the various constituents (surface of the interlayer of rough and irregular lamination before heating), and possibly the application of pressure outside the laminated structure to promote bonding and lasting cohesion of the assembly.

- The steps in which the laminated structure is subjected to a vacuum are for example carried out by tight confinement of the entire periphery, such as by means of a peripheral envelope of elastomer type often designated by the English terms "vacuum ring" and aspiration in the peripheral volume confined by a hole in this envelope;

according to an alternative, the steps in which the laminated structure is subjected to a vacuum are carried out by means of a vacuum enclosure or a vacuum bag

For the assembly of laminated glazing in which a waterproof elastomer envelope is fitted over the entire peripheral part, provided with an orifice by which a vacuum is applied by suction. The waterproof envelope is often referred to by the English term "vacuum ring". We therefore vacuum to evacuate the air present in the cold laminated structure for at least 30 min, in this case 90 min, then we heat while continuing to vacuum

The duration can be adjusted according to the thickness of the first sheet of glass. This solution is compatible with glazing that needs to be toughened.

Screen printing is a well-known printing technique which uses a screen printing screen consisting of a fabric on which the patterns to be printed on the substrate are reproduced and a doctor blade making it possible to apply a sufficient shear force to pass the paste through the meshes of the screen through the openings corresponding to the pattern to be printed and deposit said paste on the substrate.

To obtain a substrate comprising a discontinuous diffusing layer based on enamel, the composition in the form of paste is applied to the substrate then undergoes a heat treatment at a temperature and for a time sufficient to allow the melting of the frit and the formation of porosities.

The glass frit is preferably obtained by melting raw materials and then forming the frit. The raw materials (oxides, carbonates ...) can be melted at temperatures of the order of 950 to 1100 ° C, then the glass obtained can be cast, for example laminated between two rollers. The glass obtained can then be ground, for example in a ball mill, a jet mill, a ball mill, or an attrition mill.

The glass frit is preferably in the form of particles whose D90 is at most 20 μm, in particular 5 μm, or even 4 μm. The particle diameter distribution can be determined using a laser granulometer.

In the case of screen printing, it is preferable to use a screen in textile or metallic mesh, topping tools and a doctor blade, the control of the thickness being ensured by the choice of the mesh of the screen and its tension, by the choice of the distance between the glass sheet and the screen, by the pressures and speeds of movement of the doctor blade.

To obtain the enamel paste, the glass frit (s) are mixed, that is to say the compounds which form the matrix, and preferably only the organic medium.

The glass frit is previously finely ground (D50 - 2 to 5 μm) in particular to facilitate its passage through the meshes of a screen printing screen. The glass frit and the diffusing elements are dispersed at high shear in the medium using a disc disperser. Dispersion can be improved by using a three-cylinder mill.

The organic compounds of the organic medium are preferably chosen for their low vapor pressure so as not to dry in the screen printing screens.

The organic compounds are preferably at a high boiling temperature of the order of 200 ° C.

The solid / liquid ratios are preferably chosen to obtain a paste of suitable viscosity.

The organic medium can comprise or even consist of one or more of the following organic compounds of alcohols, esters, glycols, in particular esters of glycol, of terpineol. The terpineols, or terpinols or even terpinoles, are monoterpene alcohols (monoterpénols) monocyclic unsaturated of crude formula CioHi ₈ 0;

The medium can comprise or even consist of one or more of the following organic compounds: ethyl ether and diethylene glycol, butyl ether of diethylene glycol, vegetable oils, mineral oils, petroleum fractions of low molecular weight, tridecyl alcohol, synthetic or natural resins (for example cellulosic resins or acrylate resins), propylene glycol (PM) monomethyl ether, dipropylene glycol monomethyl ether (DPM), monomethyl ether of tripropylene glycol (TPM), propylene glycol mono-n-butyl ether (PnB), dipropylene glycol mono-n-butyl ether (DPnB), tripropylene glycol mono-n-butyl ether, ether propylene glycol mono-n-propyl (PnP), dipropylene glycol mono-n-propyl ether (DPnP), tripropylene glycol n-butyl ether (TPnB), propylene monomethyl ether acetate glycol (PMA), Dowanol DB (diethylene glycol monobutyl ether) sold by Dow Chemical Company, USA, or other ethers of ethylene glycol or propylene glycol.

Additives may be added in order to obtain a paste whose shear-thinning properties are satisfactory to allow the transfer of the paste from the screen to the substrate. These additives can be cellulose fragments or acrylates.

According to an advantageous embodiment, the enamel paste is obtained from a composition comprising or even consists of:

- from 70 to 80% by mass of a borosilicate glass frit of zinc and / or bismuth, preferably a glass borosilicate frit of zinc or even bismuth, and in particular the compositions indicated above

- from 20 to 30% of the medium (organic), in particular water-soluble.

Cooking can preferably be in radiative (exclusive) mode.

The present invention will be better understood and other details and advantageous characteristics of the invention will appear on reading the examples of automobile glazed light device according to the invention illustrated by the following figures:

- Figures 1a, 1b, 1c, 1d, 1e, 1f, 1g are sectional views of glazed glazing according to the invention obtained by scanning electron microscopy.

- Figures 1h, 1i are photographs of the surface of glazed glazing according to the invention with a reference pattern behind.

- Figures 1j is a view of the surface of an enamelled glazing according to the invention obtained by optical microscope.

- Figure T shows a schematic sectional view and partial of a luminous laminated glazing of a motor vehicle comprising an enameled glazing lit by the edge in a first embodiment of the invention.

- Figure 1 ”represents a schematic sectional view of a luminous automobile roof using luminous glazing according to the invention like that of FIG. 1.

- Figure 2a shows a schematic sectional view of a laminated luminous glazing comprising an enameled glazing illuminated by an internal edge which is the wall of a closed hole passing through in an embodiment of the invention.

- Figure 2b shows a schematic sectional view of a luminous glazing (for example) laminated comprising an enameled glazing illuminated by an internal edge which is the wall of a closed through hole in another embodiment of the invention.

- Figure 2c shows a schematic front view of an enamelled glazing illuminated by an internal edge which is the wall of a closed through hole in an embodiment of the invention.

- Figure 3a shows a schematic sectional view of a laminated luminous roof comprising an enameled glazing illuminated in an embodiment of the invention; with the diffusing layer forming internal signage

- Figure 3b shows a schematic front view of a laminated luminous glazing comprising an enameled glazing illuminated in an embodiment of the invention; with the diffusing layer.

- Figure 3c shows a schematic sectional view of a laminated luminous glazing comprising an enameled glazing illuminated in an embodiment of the invention; with the diffusing layer.

- Figure 4 shows a schematic sectional view of a monolithic luminous glazing in an embodiment of the invention.

- Figures 5 to 7 show different schematic views of different cars with luminous glazing according to the invention.

I. Examples of simple glazed glazing

To make simple glazed glazings, Planiclear® glasses sold by the company Saint-Gobain with a thickness of 4 mm are used. Their T _L is 92% and their blur is at most 0.08%.

The "enamel" paste used is a composition which first comprises a glass frit based on zinc borosilicate and in some cases bismuth.

Four examples of the composition of glass frits A to D and their Tg are given in Table 1 below.

% weight / Ref composition AT B VS D ZnO 46.3 18 20.9 18.9 B2O3 25.2 15.6 9.7 13.2 N32O 11.0 13.0 11.1 si0 ₂ 12.5 6.0 43.0 50.7 Al2O3 1.5 2.9 0.6 ZrO ₂ 2.7 5.7 1.7 B12O3 54.0 K ₂ O 0.9 3.2 0.2 TiO ₂ 7.1 1.1 SrO 2.2 Total 99.2 100% 99.8 99.7 Tg <590 ° C <590 ° C <590 ° C <590 ° C

Table 1

The chemical analysis was carried out by X-ray fluorescence (XRF) and by ICP-AES to evaluate the boron (lithium was not detected).

When the sum of the oxides is not 100%, this can be attributed to impurities (less than 0.3%) within the vitreous matrix.

The "enamel" paste used is a composition which comprises, in addition to the glass frit, a medium serving as an organic binder and providing a rheology adapted to a screen printing medium. This medium is for example water-soluble.

The “enamel” paste A1 comprises, relative to the total mass of the composition:

- 75% of component A

- 25% of the organic medium which is water-soluble and made up of solvents of the glycol ether type and of polymeric resin of the cellulose fragments type.

The “enamel” paste B1 comprises, with respect to the total mass of the composition:

- 75% of component B

- 25% of the organic binder medium which is water-soluble and based on solvents of the glycol ether type and of polymeric resin of the cellulose fragments type.

The “enamel” paste C1 comprises, with respect to the total mass of the composition:

- 75% of component C

- 25% of the organic binding medium which is not water-soluble based on alcohol diacetone.

The “enamel” paste D1 comprises, with respect to the total mass of the composition:

- 75% of component D

- 25% of the organic binder medium which is not water-soluble based on alcohol diacetone. The wet thickness E _h of the enamel paste layer deposited by screen printing with a suitable screen on the glass sheet varies according to the tests from 12 to 25 μm and never exceeds 40 μm.

The viscosity is preferably between 8 and 12 Pa.s.

Drying is then carried out under infrared lamps with a power of 1800W, making it possible to reach 150 ° C. in 140s. This is to eliminate the majority of solvents. It should be noted that pre-drying has a positive effect on the quality of the layer, in particular preventing the trapping of dust, etc.

The oven baking temperature (much higher than that of the Tg) also varies according to the tests between 640 ° C and 720 ° C (set temperature of the oven). The cooking time also varies according to the tests between 180s and 400s.

The enamel diffusing layer thus obtained is a flat 15 cm by 6 cm.

Light transmission, blurring and image clarity measurements were made. For a given composition, the TL, the blur, the sharpness of the image of the diffusing layer vary according to the wet thickness deposited as well as the cooking (temperature).

It is possible to optimize these characteristics of the diffusing layer by adjusting the printing parameters (wet thickness deposited) and the baking parameters (temperature) and even the type of oven (radiative, converts).

However, the light extraction capacity (evaluated by the desired luminance criterion) requires a compromise. Indeed, too weak a blur means zero or insufficient extraction.

Series n ° 1

In this first series of eight tests 1a to 4, the oven used is exclusively radiative. The results are reported in Table 2 below.

Ex Ref ref T ° C time (s) E _h (pm) E1 (Pm) TL (%) H (%) Image sharpness (%) 1a AT 710 180 25 10 87 7.9 97.5 1b AT 710 180 14 6.5 89.1 4.1 97.4 1 C AT 680 180 25 10 86.7 10.1 96.4 1d AT 640 400 25 10 84.9 14.5 97.8 2 B 720 180 20 8.5 83.5 22.5 92.8 3a VS 710 220 22 9 89 10.9 44 3b VS 710 220 16 7 89.6 14.0 48 4 D 720 180 22 9 87.5 13.4 54.2

Table 2

All samples have high light transmission. The blurring ranges from 4.1% to 22.5%, the image sharpness from 44% to 97.8%. Image clarity is the most discriminating visual criterion (the most dispersed results). Regardless of the light extraction, the best results are for tests with composition A.

For composition B, the blur is much higher but the sharpness is retained. For compositions C and D the blur is slightly higher but the sharpness is degraded.

The thickness-diffusing layer was observed with a scanning electron microscope tests 1a, 2, 3a.

Figures 1a to 1g thus show sectional views of the diffusing layer at different scales.

The thickness of the enamel layer is constant.

In FIGS. 1a and 1b, we observe for sample 1a closed and unconnected spherical porosities 3, the majority of which have a diameter D ranging from 1 pm to 6.5 pm. These porosities are close to the free surface.

In FIGS. 1c, 1d and 1e, we observe for sample 3 closed and unconnected spherical porosities 3 of diameter D ranging from 0.3pm to 8pm.

In FIG. 1d, porosities 3 of the following size are detected: 320nm, 490nm 510nm, 700nm, 930nm, 1390nm, 1680nm, 2030nm, 2190nm.

In FIG. 1e, porosities of the following size are detected: 920nm, 1110nm, 1750nm, 1310nm, 7700nm.

These porosities are as close to the interface with the glass as to the free surface.

Figures 1f and 1g show for sample 2 closed and unconnected spherical porosities, the majority of which have a diameter D of less than 0.5 μm. These small porosities are close to the free surface.

The surface of test 1a was also observed by optical microscopy as shown in FIG. 1j at a magnification of 600. The porosities 3 can be distinguished by contrast.

Figures 1h, 1i are two photographs of the surface of the sample 1a with a reference pattern 23 behind:

- parallel black bands (Figure 1 h),

- 7 lines of capital letters decreasing in size from bottom to top (Figure 1 i).

These test patterns 23 are remarkably identifiable.

Although references C and D have a level of image clarity (%) significantly lower than the other references, these two references have improved chemical resistance, for example in the following cases:

- exposure to high humidity and high temperature for 56 days (EN 1096)

- exposure to corrosive cleaning products.

The gloss is measured in UB gloss unit with a Glossmeter, with the MICRO TRIGLOSS device (BYK-GARDNER) according to Standard ISO 2813 (measurement on the diffusing layer side with an angle of 60 °).

The fusibility of the enamel of component A results in a smooth layer surface which gives a high gloss greater than 140 UB. The gloss decreases slightly with thickness. The gloss of the enamel in component B is also greater than 100 UB. On the other hand, the gloss of the enamel of component C is 40 UB. The gloss of the enamel of component D, on the other hand, is 50 BU.

A diode module (SAMSUNG V2.2 module - 28 _ 120116) with 12V voltage is placed opposite the edge of the glass sheets. The emission angle is 120 °. The flux is 89 Lumens.

To assess luminance L at normal, the Lumicam ref 1201 device is used.

The results are recorded in Table 3 below with an assessment of the quality as a function of the transparency (especially blurring) and of the light extraction.

Ex Ref ref E1 (Pm) TL (%) H (%) Image sharpness (%) L (Cd / m ² ) Quality Blur / extraction 1a AT 10 87 7.9 97.5 82 +++++ 1b AT 6.5 89.1 4.1 97.4 40 ++++ 1 C AT 10 86.7 10.1 96.4 77 ++++ 1d AT 10 84.9 14.5 97.8 98 +++ 2 B 8.5 84.1 21.1 92.9 63 ++ 3a VS 9 89 10.3 44 52 + 3b VS 7 89.6 13.5 50.9 41 + 4 D 9 87.5 12.8 54.6 65 +

Table 3

The luminance varies from 40 to 98 Cd / m ² . The highest blur (test 2) does not necessarily imply the highest luminance. Thus, for a given thickness, the best results are obtained with composition A than with composition B which is differentiated by its high bismuth content.

Series # 2

In this second series 1e to 1d, composition A is kept with the two possible thicknesses. The viscosity is fixed at 12 Pa.s.

The major difference is that the oven used is convective with introduction into the heating body of air flows of variable pressures (increasing with frequency F), with temperatures varying between 690 ° C and 710 ° C.

The results are in table 4 to be compared with the preceding cases 1a and 1b (delivered) in exclusive radiative mode (F = 0).

A diode module (Module 5 SAMSUNG V2.2 - 28 _ 120116) with 12V voltage is placed opposite the edge of the glass sheets. The emission angle is 120 °. The flux is 89 Lumens.

To assess luminance L at normal, the Lumicam ref 1201 device is used.

The results are reported in Table 4 below with an assessment of the quality as a function of the transparency (especially blurring) and of the light extraction.

Ref T ° C duration (S) F z) E _h (pm) E1 (Pm) TL (%) H (%) Image sharpness (%) L (Cd / m ² ) Quality Blur / extr action 1a 710 180 0 25 10 87.0 7.9 97.5 82 +++++ 1b 13 6.5 89.1 4.1 97.4 40 ++++ first 690 170 30 25 10 86.1 9.5 97.1 72 ++++ 1f 13 6.5 90.9 1.2 98.9 12 - first 690 170 50 25 10 85.8 9.9 96.8 79 ++++ 1f 690 170 50 13 6.5 90.8 1.4 10 - 1g 700 170 50 25 10 89.4 3.8 98.6 35 +++ 1i 710 10 30 25 10 90.4 1.9 99.2 18 -

Table 4

The fusibility of the enamel of component A results in a smooth layer surface which is given by a high gloss (greater than 100) measured with the Glossmeter, with the MICRO TRIGLOSS device (BYK-GARDNER) according to the Standard. ISO 2813 (measurement on the diffusing layer side with an angle of 60). The gloss decreases slightly with thickness.

Although references C and D have a level of image clarity (%) significantly lower than the other references, these two references have improved chemical resistance, for example in the following cases:

- exposure to high humidity and high temperature for 56 days (EN 1096)

- exposure to corrosive cleaning products.

Analysis of the results in Tables 2 to 4 leads to the following trends.

For a given temperature in radiative mode as convective, the increase in thickness greatly increases the luminance, because the number of porosities of suitable size increases statistically.

For the most limited level of blurring possible, the luminance is better in radiative mode than in convective mode.

In radiative mode, with regard to composition A, the best compromise (low blurring, high sharpness, sufficient luminance) is obtained with a temperature greater than or equal to 710 ° C. Luminance remains high at lower temperature

Conversely, for a convective mode, concerning composition A, good results are observed as long as the temperature is not too high, less than or equal to 690 ° C.

At 710 ° C and 720 ° C, very few porosities remain.

It should be noted that the luminance is similar on the layer or opposite side and that the luminance is stable: (same result along the perpendiculars to the diodes).

Other details and advantageous characteristics of the invention will appear on reading the examples of the glazed luminous device according to the invention illustrated by the following figures.

II. Examples of automotive light glazing devices according to the invention

It should be noted that for the sake of clarity the various elements of the objects represented are not necessarily reproduced to scale.

FIG. T represents a schematic sectional and partial view of a luminous laminated glazing of a motor vehicle 100 in a first embodiment of the invention.

In FIG. T, it is a laminated glazing 100 which is a roof with a section and external main faces called face F1 and face F4 comprises:

a first sheet of glass 1, forming internal glazing, cabin side, for example rectangular (of dimensions 300 × 300 mm for example), made of mineral glass, having a main face 11 corresponding to the face F3 and another main face 12 which is the face F4, and a slice 10 preferably rounded (to avoid flaking) here longitudinal slice (or as a lateral variant), for example a sheet of silica-calcium lime glass, extraclear as diamond glass sold by the company Saint-Gobain Glass, of equal thickness for example at 2.1 mm, glass of refractive index n1 of the order of 1.51 to 550 nm or the Optiwhite glass of 1.95 mm, possibly with a stack of ΙΊΤΟ 18 opposite F4 (passenger compartment side)

- a lamination interlayer 6 ′, for example a clear PVB with a thickness of 0.76 mm, preferably fuzziness of at most 1.5%, with a slice 61 here longitudinal offset from the longitudinal slice 10 towards the center of the glass, lamination interlayer with refractive index n _f less than n1, equal to 1.48 to 550nm

- a second sheet of glass T, of the same dimensions, forming external glazing, with a composition for a tinted solar control function (VENUS VG10 or TSA 4+ glass sold by the company Saint-Gobain Glass) for example of equal thickness by example 2.1 mm) and / or covered with a solar control coating (or a tinted plastic film), with a so-called internal or laminated main face 13 or F2 opposite the face 12 or F3, and another main face 14 corresponding to the face F1, and a section 10 'here longitudinal.

The laminating interlayer 6 ’is preferably made of PVB which can be tinted and / or acoustic. The laminating interlayer may comprise a transparent polymeric sheet, for example a PET, in particular covering the surface, for example at least 90%. This sheet may be coated with a transparent electroconductive coating, for example for solar control and / or component supply. For example, it is all PVB / sheet / PVB and in particular PVB / PET / PVB.

The first glass sheet 1 here has a peripheral recess or through hole along the longitudinal section 10, preferably of dimension smaller than the longitudinal section.

Light emitting diodes 4 extend along the edge of the first glass sheet 1. These are side emission diodes housed in the recess. Thus these diodes 4 are aligned on a PCB support 41, for example a parallelepiped strip, preferably as opaque as possible (not transparent) and their emitting faces are parallel to the PCB support and facing the wafer 10 in the wafer part recessed. The PCB support is fixed for example by glue 6 (or a double-sided adhesive) on the edge of the face F2 13, and here is engaged in a groove between the faces F2 and F3 made possible by sufficient removal of the wafer 60 of the PVB. A peripheral masking strip 7 in opaque enamel is added to the face F2 which can mask the PCB support and even the outgoing light in this area.

The light-emitting diodes 4 each comprising an emitting chip capable of emitting one or more radiation in the visible guided (s) in the first glazing. The diodes are small, typically a few mm or less, in particular of the order of 2x2x1 mm, without optics (lens) and preferably not pre-encapsulated to reduce the overall dimensions as much as possible.

The distance between the diodes and the slice 10 is reduced as much as possible, for example from 1 to 2mm. The main direction of emission is perpendicular to the face of the semiconductor chip, for example with an active layer with multi quantum wells, of AlInGaP technology. or other semiconductors. The light cone is a Lambertian type cone, +/- 60 °. As an example, the diodes (a dozen) have an individual power of 50mW to 100mW, over a length of 20 mm, or a power of 3 to 4W / m. The space between each chip and the optically coupled wafer 10 can be protected from any pollution: water, chemical, etc., this in the long term as during the manufacture of the luminous glazing 100.

In particular, it is useful to provide the luminous glazing with a polymeric encapsulation 8, about 2.5 mm thick, at the edge of the glazing. This encapsulation ensures long-term sealing (water, cleaning product, etc.). The encapsulation also provides a good aesthetic finish and allows the integration of other elements or functions (reinforcement inserts ...).

The encapsulation 8 is two-sided: facing the edge of the laminated glazing (in contact with the edge 10 ′ with or without adhesion primer) and partly at the edge of the face A and has a lip. The encapsulation 8 is for example in black polyurethane, in particular in PU-RIM (reaction in mold in English). This material is typically injected up to 130 ° C and a few tens of bars.

The black encapsulation material is therefore not transparent to the visible radiation (s) from the diodes. To ensure a good injection of light into the first glazing, therefore, means of sealing against the liquid encapsulation material are used. For example, the diodes are covered by optical glue 6 or by a protective varnish.

As described in document WO2011092419 or document WO2013017790, the polymeric encapsulation may have a through recess closed by a removable cover to place or replace the diodes.

The luminous glazing 100 may have a plurality of light zones, the luminous zone or zones preferably occupying less than 50%, of the surface of at least one face, in particular of given geometry (rectangular, square, round ...)

The light ray A (after refraction on the edge 10) propagates by total internal reflection (at the level of the face F3 and of the face F4) in the first glazing 1 forming a light guide.

For light extraction, the enamel diffusing layer 2 according to the invention is deposited on the face F3 12 (or F4 11 as a variant). It comprises a transparent matrix 20, preferably colorless, incorporating diffusing porosities 3 (as shown in FIG. 1a for example). In particular, the transparent matrix has an index of refraction n2 at least equal to n1 or such that n1-n2 is at most 0.15.

The diffusing zone 2 is for example rectangular 10 cm by 10 cm, is a solid, continuous layer. We can use a more or less fine screening for example with coverage rates for example between 75% and 90%

Several series of diodes can be provided (one edge, two edges, three edges, all around the periphery). Layer 2 can be a flat forming a strip, a light frame, and / or it can be one or more lines, for example of 0.4mm, spaced less than 5cm also on one edge, two edges, three edges, all over the periphery of the face F3 or F4.We can form pictograms, light circles etc.

It is possible to have several series of diodes controlled independently and even of different color. We can choose diodes emitting white or colored light for mood lighting, reading ... We can choose a red light for signaling possibly alternating with green light.

The deposition of the diffusing layer 2 can be carried out before or after bending (quenching). We observed on face F3 a better off state rendering than on face F4, the edges of the enamel are much less visible, surely because there is a difference in enamel / PVB index less favorable to refraction.

Alternatively, the diffusing layer 2 is on the face F4, for example for process reasons, on the possible thermal comfort layer 18.

To mask the stray light visible on the face F1 side, an opaque enamel 7 is used on the edge of the laminated face F2.

The roof 100 can for example form a fixed luminous panoramic roof 1000 of a motor vehicle such as a car, mounted from the outside on the bodywork 8 ’via an adhesive 61’ as shown in FIG. 1 ”.

This laminated luminous glazing 100 can alternately form a front or rear quarter window (possibly by eliminating the encapsulation). The diffusing layer forms for example a flashing repeater or a LOGO. It is on the first clear or extra-clear glazing, here the outermost, on the F1 face or preferably on the F2 face on the laminated face side. Optionally an opaque masking layer is on the internal glazing - tinted or not, for example on the face F3.

This laminated luminous glazing can alternatively form a front windshield (possibly by eliminating or adapting the encapsulation). The diffusing layer forms, for example, an anti-collision signal for the conductor and is on the innermost first clear or extra-clear glazing on the face F4 or on the face F3 in particular forming a strip along the lower longitudinal edge. For example, the light turns on (red) when a vehicle in front is too close. The second glazing is also clear or extra clear glass.

Of course, laminated glazing, in particular a roof, may include other elements such as:

- one or more sensors

- a liquid crystal device, offset or opposite the diffusing layer, within the PVB 6 ’

- a functional layer (on a PET film, etc.) within the laminate, etc.

FIG. 2a represents a schematic sectional view of a laminated luminous glazing 200a comprising an enameled glazing illuminated by an internal edge which is the wall of a closed through hole in an embodiment of the invention.

As in FIG. 1 ’, the laminated glazing 200a comprises a first sheet 1, bonded via a laminating intermediate 6’ to a second sheet of glass T. The peripheral sections are not shown.

A through hole 15 has been drilled through the second sheet T, the lamination interlayer 6 ′ and the first sheet 1, creating in the latter an internal wafer 16. The through hole in the second sheet is obstructed by an element of opaque obstruction 75 flush with the face F1 14.

In the through hole 15 of the first sheet 1 are housed LEDs 4 with their emitting face facing the internal edge 16 (front emitting diodes). The LEDs 4 are supported by a removable opaque cover 9, fixed via clips 16 ′ to the face F4 11. The diffusing layer of transparent enamel 2 is located in the immediate vicinity of the internal edge 16. An opaque masking enamel 17 on the face F2 is provided to prevent the direct emission of light by the LEDs 4 to the outside of the vehicle.

Although it does not appear in this figure, the through hole 15, the LEDs 4, the opaque cover 9 and the diffusing layer 2 have a circular central symmetry.

In a variant not shown, the through hole was drilled only in the first sheet and the lamination interlayer, while the second sheet T is not drilled. An opaque black enamel can play the role of masking towards the outside. On this enamel is fixed the LEDs arranged so that their emitting faces are facing the internal edge of the through hole.

In another variant, it is a monolithic glazing (bezel, lateral, etc.) and the hole preferably is through and obstructed.

FIG. 2b represents a schematic sectional view of a luminous glazing (for example) laminated glass 200b comprising an enameled glazing illuminated by an internal edge which is the wall of a closed hole passing through in another embodiment of the invention, variant of the previous one.

It differs from the previous 200a in that the through hole 15 extends here only through the first sheet 1. The second sheet 2 and the lamination interlayer 3 are then not drilled.

The inorganic light-emitting diodes 4 (LEDs or LEDs) are side-emitting LEDs have an emission surface in a main emission direction substantially orthogonal to the emission surface.

Diodes with side emission have the advantage of having a smaller footprint than diodes with front emission. On the other hand, the front emission diodes are more powerful and less expensive than the side emission diodes.

The diodes 4 are mounted on a diode support 41 such as an integrated circuit card (PCB in English). The support 41 is preferably common to all the diodes 4. Alternatively, each diode can be arranged on an individual support, or several diodes 4 can be mounted on the same support.

The support 41 comprises a main front face carrying the diodes and an opposite rear main face, for example glued to the interlayer 6 'with an adhesive 9. The mounting support has a thickness preferably less than 500 μm, and more preferably less than 200 μm .

The glazing 200b also includes a guide element 90 for the light emitted by the diodes 4. The guide element 90 is configured to inject the light from the diodes 4 into the first sheet 1 via the internal wall 16 formed by the through hole 15 The guide element 90 comprises an inlet face 91 and an outlet face 92 as well as a body 93 delimited by the inlet face 91, the outlet face 92 and external walls.

The diodes 4 are arranged so that their emitting surface is opposite, and close to, the input face 91 of the guide element 90, spaced apart or in contact. The emitting surface of each diode 4 and the input face 91 of the guide element 90 are spaced at most 1 mm, preferably at most 5 mm, spaced or even in contact, for example in optical contact (by glue) or physical contact.

The guide element 90 is used to optimize the injection of light into the first sheet 1. The guide element 90 can have a wide variety of shapes so as to adapt to different configurations of type and positioning of the diodes

The arrows indicate the direction of propagation of the light emitted by the diodes. The arrow coming from the emission surface of a diode 4 also symbolizes the main emission direction of this diode

The light injected through the internal wall 16 is guided by the first sheet 1 to the diffusing layer 2 in transparent enamel, on the face F4 or alternatively F3.

As a variant, it is a monolithic glazing (bezel, lateral, etc.) and the preferably through hole is obstructed.

FIG. 2c represents a schematic front view of an enamelled glazing unit 200c lit by diodes via an internal edge which is the wall 16 of a closed through hole 15 in an embodiment of the invention. The diffusing layer 2 with its porosities 3 is in the form of discrete elements of different sizes and shapes arranged by arcs of a circle concentric with the hole, patterns:

-of oval and hollow 51 as close as possible to hole 15

-then elements 52 of square shape in the middle

- then in discs (full) 53.

The glazing is laminated as described in Figures 2a and 2b and their variants or the glazing is monolithic.

FIG. 3a represents a schematic sectional view of a laminated luminous roof 300a comprising an enameled glazing illuminated in an embodiment of the invention. This roof differs from that in Figure T in that:

- the diffusing layer 2 for example forming internal signage (pictogram, etc.) is on the periphery on the face F3 and an internal enamel masking layer 7 ’is directly on the face F4 with a saving 70’ in line with the layer 2

- The ITO layer on the F4 side is possibly removed.

In the lit state, the pictogram is not visible from the outside due to the external masking layer 7.

Alternatively, it is a windshield in particular without polymeric encapsulation. The windshield may include a heating layer such as the Climacoat layer on the face F3 and possibly under the diffusing layer.

As shown in the windshield 300b in FIG. 3b, the pictograms 2a, 2b, 2c are, for example, flashing repeaters or an alert signal (emergency triangle). We can add other patterns 2 outside the 7 ’enamelled frame area.

FIG. 3c represents a schematic sectional view of a laminated luminous glazing (windshield, rear window, side glazing) comprising an enameled glazed glazing 300c in an embodiment of the invention;

This glazing differs from that in FIG. 3a in that:

- we possibly removed the peripheral encapsulation

- the diodes are optically coupled to the edge of the clear or extra-clear T glass

- the diffusing layer 2 which, for example, forms external signage (pictogram, etc.) 2 is on the periphery on the face F2 of the clear or extra-clear exterior glass; the outer enamel masking layer 7 on the face F2 is with a sparing 70 housing the layer 2.

In the lit state, the pictogram is not visible from the inside because of the internal masking layer 7 ’.

FIG. 4 represents a schematic sectional view of a monolithic luminous glazing 400 in an embodiment of the invention.

Car luminous glazing differs from that described in FIG. T by the fact that it is a monolithic glazing (clear or extra-clear) and even without polymeric encapsulation. In addition, the diodes 4 are emission from above. The PCB support 41 is for example fixed to the edge 10 by the optical adhesive 6.

This luminous glazing forms for example a window for signaling for example.

This luminous glazing also forms a lateral glazing for signaling:

- for example detection of the vehicle (in a parking lot, etc.)

- turn signal repeater preferably in a quarter (front quarter driver side or rear quarter).

Figures 5 to 7 show different schematic views of different cars with luminous glazing according to the invention like that of Figure 4 for example.

Figure 5 shows a car with luminous glazing 500 according to the invention which is a rear window with a luminous zone for signaling. The diffusing layer 2 with the porosities forms a third stop light (diffusing strip 5 centered along the upper longitudinal edge), the diodes (masked) emitting in red.

If we choose a monolithic glazing 1, we prefer that the diffusing layer is on the side F2, in particular if the side F1 is provided with windscreen wipers. We can add a tinted plastic film internally.

If we choose a laminated glazing we prefer that the diffusing layer is on the laminating face called F2 of the first outermost glazing 1 (clear glass like Planilux, or Planiclear or extra clear glass like Diamond or Optiwite), in particular if the F1 side is fitted with windscreen wipers.

Figure 6 shows a car with the luminous glazing 600 which is a rear window with a luminous zone for external signaling. The diffusing layer 2 with the porosities forms indicators 2 or indicators repeaters (two arrows 5 of opposite direction directed towards the outside of the glazing and near the side edges). We may prefer to put the diodes (hidden here) on each side edge.

If a monolithic glazing is chosen, it is preferable for the diffusing layer 2 to be on the face F2 12, in particular if the face F1 is provided with wipers. We can add a tinted plastic film internally.

If we choose laminated glazing we prefer that the diffusing layer is on the F2 side of the outermost first glazing 1 (clear glass like Planilux, or Planiclear or extra clear glass like Diamant or Optiwite), in particular if the F1 side has 'windscreen wipers.

FIG. 7 shows a car with luminous glazing 700 which is a rear window with a luminous zone for exterior signaling. The diffusing layer 2 can form an emergency light signal, in red, in the well-known shape of a light triangle with a central exclamation point.

If a monolithic glazing is chosen, it is preferable for the diffusing layer to be on the face F2 12, in particular if the face F1 is provided with wipers. We can add an internally tinted plastic film.

If we choose laminated glazing we prefer that the diffusing layer is on the F2 side of the outermost first glazing 1 (clear glass like Planilux, or Planiclear or extra clear glass like Diamant or Optiwite), in particular if the F1 side has 'windscreen wipers.

Claims (25)

1. Enamelled substrate (100 to 700) for automotive glazed light device comprising: - a first glass sheet (1) comprising on a first main face (12) a diffusing layer (2), in enamel, comprising a matrix (20) made of a vitreous material and diffusing elements characterized in that: - the diffusing layer is of thickness E1 of at least 5pm and at most 20pm: the glassy material is based on zinc borosilicate and / or bismuth, the matrix is porous, said diffusing elements are gas or vacuum porosities (3), of characteristic dimension, in particular a diameter, of at least 0.2 μm, - said diffusing elements are free of diffusing particles or with a content by weight of diffusing particles of at most 10% of the total weight of the enamel, the entire first sheet of glass and diffusing layer having: - a light transmission factor of at least 75%, - blurring of at most 30% and at least 1%. 2. Enamelled substrate for a glazed automotive light device according to the preceding claim, characterized in that the blur is at most 20% or at most 10%. 3. Enamelled substrate for a glazed automotive light device according to one of the preceding claims, the first glass sheet and diffusing layer assembly has a sharpness of at least 85%, or at least 90%. 4. Enamelled substrate for a glazed automotive light device according to one of the preceding claims, characterized in that the content by weight of diffusing particles is at most 5% of the total weight of the enamel; better at most 1%, preferably zero. 5. Enamelled substrate for a glazed automotive light device according to one of the preceding claims, characterized in that the porosities, in particular spherical and / or elliptical, have a diameter D1 <E1 and at most 10pm or 6pm in particular with E1 d '' at most 15 pm and preferably D1 at least 0.8 pm and / or the ratio E1 / D1 is at least 0.4 in particular with E1 at most 15 pm. 6. Enamelled substrate for a glazed automotive light device according to one of the preceding claims, characterized in that said vitreous material has a chemical composition such that the cumulative content by weight of ZnO + B ₂ O3 + Bi ₂ O3 + SiO ₂ + Na ₂ Oest at least 80% of the total weight of the vitreous material, and even the cumulative weight content of ZnO + B ₂ O ₃ + SiO ₂ + Na ₂ O is at least 80% of the total weight of the vitreous material. 7. Enamelled substrate for a glazed automotive light device according to one of the preceding claims, characterized in that said vitreous material has a chemical composition such that the weight content of alumina is at least 1% of the total weight of the vitreous material and preferably at most 8% and the content by weight of zirconium oxide is at least 1% of the total weight of the vitreous material and preferably at most 8%. 8. Enamelled substrate for a glazed automotive light device according to one of the preceding claims, characterized in that said vitreous material has the chemical composition which comprises or consists of the following constituents, varying within the weight limits by weight of the vitreous material defined below : ZnO 31-55% B ₂ O ₃ 15-30% SiO ₂ 5-20% and even 10-20% Na ₂ O 5-15% with ZnO + B ₂ O ₃ + SiO ₂ + Na ₂ O> 80% or 90% and preferably AI ₂ O ₃ 1-5% ZrO ₂ 1-5% Bi ₂ O ₃ 0-10% and even 0-2% TiO ₂ 0-10%. 9. Enamelled substrate for a glazed automotive light device according to one of claims 1 to 6 characterized in that said vitreous material has the chemical composition which comprises or consists of the following constituents, varying within the weight limits by weight of the vitreous material below. after defined: SiO ₂ 31-60% and even 40% -60% ZnO 15-30% B ₂ O ₃ 8-20% and even 8-15% Na ₂ O 5-20% and even 8-18% with SiO ₂ + ZnO + B ₂ O ₃ + Na ₂ O> 80% or 90% and preferably AI ₂ O ₃ 0.5-5% ZrO ₂ 0-5% Bi ₂ O ₃ 0-10% and even 0-2% TiO ₂ 0-12% and even 0-10%. 10. Enamelled substrate for automotive light glazing device according to one of the preceding claims, characterized in that the diffusing layer (2) has a gloss of at least 100 and better still at least 120. 11. Enamelled substrate for a glazed automotive light device according to one of the preceding claims, characterized in that the glass (1) is silico-soda lime, with the first sheet of glass having only a light transmittance of at least 90%, preferably within the meaning of standard EN 410: 1998. 12. Enamelled substrate for automotive light glazing device according to one of the preceding claims, characterized in that the first glass sheet (1) is toughened and / or curved. 13. Enamelled substrate for a glazed automotive light device according to one of the preceding claims, characterized in that the first glass sheet (1) has on a second main face opposite the first main face and / or on the first face. , under the diffusing layer and / or adjacent to the diffusing layer, a transparent functional layer, in particular facing the diffusing layer, chosen from at least one of the following layers: a layer of silica, in particular porous, for example sol gel - a masking layer adjacent to the diffusing layer, in particular peripheral layer, in particular an enamel layer - an electrically conductive layer, in particular an electrode, a power supply layer of (opto) electronic components or a heating layer, in particular a layer of transparent conductive oxide, - a solar control (and /) or low emissivity layer (18), in particular a coating comprising a functional layer of transparent conductive oxide or a functional metallic layer. 14. Enamelled substrate for a glazed automotive light device according to one of the preceding claims, characterized in that the surface of the diffusing layer is a free surface or covered by a transparent element preferably of thickness at most 1.5 mm or submillimetric , in particular which is a polymeric film in adhesive contact with the diffusing layer or which is an overlay. 15. Enamelled substrate for a glazed automotive light device according to one of the preceding claims, characterized in that the first glass sheet comprises a masking layer, in particular enamel, adjacent to the diffusing layer or on the second face offset from the layer diffusing, in particular peripheral masking layer along the optical coupling wafer with a light source. 16. Enamelled substrate for a glazed automotive light device according to one of the preceding claims, characterized in that the first glass sheet is part of a laminated glazing comprising: - said first sheet, preferably in clear or extra-clear glass - a lamination interlayer (6 ’) preferably in PVB, possibly tinted - And a second transparent sheet (T), in particular of glass, preferably tinted preferably the first main face is the internal main face, on the laminating interlayer side and even in adhesive contact with the laminating interlayer. 17. Enamelled substrate for a glazed automotive light device according to claim 16 characterized in that the first sheet is the internal glazing and preferably the first main face (12) is the internal face called face F3. 18. Enamelled substrate for automotive light glazing device according to one of claims 1 to 16 characterized in that the first sheet is the external glazing and preferably the first main face (12) is the internal face called face F2. 19. Enamelled substrate for a glazed automotive light device according to one of the preceding claims, characterized in that it forms: - a laminated, curved roof, the first sheet of glass is the internal glazing - a window, in particular the first sheet of glass is the external glazing, the diffusing layer is on the passenger compartment side - one side, the first sheet of glass is the internal or external glazing - a laminated, curved windshield, the first sheet of glass is internal or external glazing. 20. Enamelled substrate for a glazed automotive light device according to claim 16 characterized in that the first main face (12) is the internal face called face F3 and the second glass sheet comprises a peripheral masking layer, in particular enamel with a saving in right of the diffusing layer. 21. automotive light glazing device comprising an enameled substrate according to one of the preceding claims characterized in that it further comprises a light source which is optically coupled to the first glass sheet, in particular to the edge or to a wall of a hole in the first glass sheet, direct optical coupling or by means of an optical system, possibly a light source within said hole. 22. automotive glass glazing device according to the preceding claim characterized in that the light source comprises a plurality of inorganic light emitting diodes. 23. Method for manufacturing an automotive enameled substrate for a glazed luminous device according to one of the preceding claims for the enameled substrate characterized in that it comprises the formation of a diffusing layer involving in this order: 0 - depositing on the first sheet of soda-lime glass preferably by screen printing of a liquid composition comprising a glass frit and an organic medium, of thickness at least 10 μm and at most 40 μm - cooking at a temperature between 630 ° C and 720 ° C especially for a period of at most 650s. 24. Method for manufacturing an enamelled substrate for a glazed luminous device according to one of the preceding claims, characterized in that it comprises, before cooking, drying at a temperature of at most 200 ° C or 150 ° C and preferably from 110 ° C to 130 ° C. 25. Method for manufacturing an enameled substrate for a glazed luminous device according to one of the preceding claims for a method characterized in that the first 15 sheet of glass being conveyed on a conveyor with the first main face opposite the conveyor side, the cooking is in an oven on the conveyor, bending oven possible, and is optionally the cooking is followed by a thermal quenching.