METHOD FOR PRODUCING AN OPACIFYING LAYER TO INCREASE THE CAMOUFLAGE CAPACITY OF A LIGHT DISPLAY DEVICE

Abstract

The invention relates to a method for manufacturing a translucent opacifying layer configured to be superimposed on a translucent interface made of non-homogeneous material in a luminous display device, comprising the steps of providing an initial virtual representation of a display face of the translucent interface, quantifying the initial colors of the initial virtual representation so as to obtain a quantified virtual representation, and reproducing the quantified virtual representation on a support to manufacture the translucent opacifying layer. figure for abstract: figure 12

Description

Title of the invention: MANUFACTURING METHOD OF AN OPACIFYING LAYER FOR INCREASING THE CAMOUFLAGE CAPACITY OF A LIGHT DISPLAY DEVICE TECHNICAL FIELD OF THE INVENTION

[0001] The invention relates to a method for manufacturing a translucent opacifying layer configured to be superimposed on a translucent interface made of non-homogeneous material in a luminous display device.

[0002] It also relates to a luminous display device comprising a translucent opacifying layer obtained by such a method.

[0003] The present invention finds its application in particular, in a non-limiting manner, in the field of luxury products, electronic devices (mobile phones, tablets, smart watches, hi-fi, televisions, drones), home automation, watchmaking, furniture, and more particularly in the field of vehicles, for example automobiles, nautical or aeronautics, to equip the passenger compartment. STATE OF THE ART

[0004] In the field of illuminated display devices, techniques aimed at improving aesthetics, performance and control discretion have led to the development of "dead front" type displays.

[0005] Such a display device is designed such that the components and / or indicators disposed in the background of the interface are substantially invisible or undetectable when the display device is in an off state, thereby promoting a clean appearance.

[0006] It generally has a uniform and often monolithic display face, which exposes little or no detail until the light source is turned on.

[0007] This type of light display device is commonly found, for example in induction hobs or in aircraft cabins.

[0008] It is generally composed of several layers, including a transparent interface made of glass or plastic having a display face, a light source arranged on the side of a rear face of the interface in order to illuminate by transmission the display face, opposite the rear face, a substrate in the form of a plate to support electronic components such as the light source, a graphic layer arranged between the interface and the light source and comprising at least one opaque part obscuring the light source and at least one transparent part or translucent allowing light to pass through so as to define one or more patterns on the display face, and an opacifying, translucent and colored layer, arranged between the interface and the light source, so as to be arranged opposite the at least one transparent or translucent part of the graphic layer.

[0009] To ensure visual homogeneity of the display face when the light source is in an off state, the graphics layer is colored uniformly, typically black, and the opacifying layer is the same color as the graphics layer.

[0010] When the light source is in an on state, the light emitted by the latter passes through the different layers so as to visibly reveal light information, such as a pattern, text or any other informative element, on the display face.

[0011] In recent developments related to illuminated display devices, interest is being shown in improving their aesthetics by using natural materials such as wood or linen, thus replacing the usual plastic or glass interfaces.

[0012] These materials may have an intrinsic characteristic of semi-opacity, as well as intrinsically non-homogeneous patterns, providing a natural camouflage capacity which masks with a certain effectiveness the components arranged in the background of the interface when the light source is in its off state.

[0013] However, the opacity of certain materials, in particular certain light wood species, proves to be insufficient to ensure effective and continuous camouflage of the components in the background, and it is then appropriate to make the interface opaque.

[0014] In the prior solutions described above, the visual appearance of the interface is determined by added layers such as the graphics layer and the opacifying layer. They are therefore not compatible with luminous display devices provided with an interface made of natural materials for which the objective is to preserve the original appearance of these materials as much as possible. Statement of the invention

[0015] The present invention aims to remedy all or part of the drawbacks of the state of the art cited above, and more particularly to provide a luminous display device comprising a translucent interface made of non-homogeneous material effectively masking the elements arranged in the background while retaining its original appearance.

[0016] In this regard, the invention aims, according to a first aspect, at a method for manufacturing a translucent opacifying layer configured to be superimposed on an interface. translucent non-homogeneous material in a luminous display device, comprising the steps of: • provide an initial virtual representation of a display face of the translucent interface, the initial virtual representation comprising a plurality of points, each point being associated with an initial color, • quantify the initial colors of the initial virtual representation so as to obtain a quantified virtual representation comprising a determined number of so-called dominant colors less than the number of initial colors of the initial virtual representation, and • reproduce the quantified virtual representation on a support to produce the translucent opacifying layer.

[0017] A non-homogeneous material is a material which, on a macroscopic scale, exhibits local variations in color, transmittance and / or light scattering. For example, lignocellulosic materials such as wood are non-homogeneous materials because it is possible to observe variations in color, texture and structure such as grain, knots and growth rings.

[0018] According to the manufacturing method of the present invention, the translucent opacifying layer is obtained from a so-called initial virtual representation corresponding to the display face of the translucent interface made of non-homogeneous material. The Applicant has found that by superimposing a translucent layer reproducing identically to the display face of the interface, the original appearance of the latter is preserved.

[0019] By quantifying the initial virtual representation, the number of colors of this initial virtual representation is reduced, which facilitates the manufacture of the translucent opacifying layer, while preserving the general appearance of the display face. Here again, the Applicant has found that by superimposing a translucent opacifying layer reproducing the general appearance of the display face of the interface, the original appearance of the latter was not, or very little, altered.

[0020] Thus, the manufacturing method makes it possible to manufacture, in a simple, convenient and economical manner, a translucent opacifying layer which, when superimposed on the translucent interface from which it was manufactured, makes it possible to increase the capacity to mask the elements arranged in the background of the translucent interface, while preserving the original appearance of the latter.

[0021] Preferred, simple, convenient and economical characteristics of the method according to the invention are presented below.

[0022] The step of providing the initial virtual representation may comprise a sub-step of capturing an image of the translucent interface. For example, each pixel of the image is representative of an area of ​​the display face measuring less than 0.5 cm by 0.5 cm.

[0023] The sub-step of capturing an image of the translucent interface can be implemented using a video colorimeter, a photographic device, a camera, such as a hyperspectral camera, or any other device provided with a CMOS sensor, for “Complementary Metal Oxide Semiconductor” in English terminology, CCD, for “Charge Couple Device” in English terminology, or more generally any device capable of providing a color image.

[0024] Alternatively, the step of providing the initial virtual representation may comprise a sub-step of reconstructing a plurality of point measurements. For example, each point measurement may be performed on an area of ​​the display face having an area measuring less than 1 cm by 1 cm.

[0025] The sub-step of capturing an image of the translucent interface can for example be implemented using a spectrometer, a spectrophotometer, a spectrocolorimeter, a colorimeter, or any other device making it possible to acquire colorimetric data.

[0026] The quantifying step may comprise the sub-steps of: • select a specific number of colors, • determine a palette of dominant colors from the determined number of colors and initial colors of the initial virtual representation, • associate each point of the initial virtual representation with the closest dominant color in the determined dominant color palette, and • replace the initial color of each point of the initial virtual representation with the dominant color with which it was associated.

[0027] The choice of the number of colors is a compromise between the precision with which the quantized visual representation can reproduce the colors of the initial virtual representation, which influences the preservation of the original appearance of the interface, and the ease of manufacturing the translucent colored layer. The higher the number of colors, the better the preservation of the original appearance of the interface but the greater the manufacturing time and resources required.

[0028] Thus, it has been established that by selecting a number of colors between 1 and 4, it is possible to obtain satisfactory conservation of the original appearance of the interface, quickly and using few resources. This is especially true when the translucent opacifying layer is reproduced by screen printing. Indeed, digital printing has the advantage of allowing rapid and resource-efficient manufacturing even with a large number of colors.

[0029] The colors or color data of each point or pixel of the initial virtual representation can be expressed in different color spaces, such as the RGB color space (for "Red Green Blue" in English terminology), CIELAB or L*a*b*, HCL (for "Hue-Chroma-Luminance" in English terminology), etc. In particular, each color or color data of each point or pixel of the initial virtual representation can be represented by a point in this space. If a set of pixels is represented, they form a cloud of points in this space.

[0030] Different methods can be used to determine the dominant color palette.

[0031] For example, the dominant color palette may be determined by uniformly dividing the color space containing the initial colors of the initial virtual representation. For example, in the RGB color space, the colors are uniformly distributed along the red, green, and blue axes, forming a regular grid in this color space.

[0032] For example, the dominant color palette can be determined using the algorithm known as "median eut". This algorithm consists of grouping all the points (pixels) of the initial virtual representation into a packet, identifying the dimension (red, green or blue) with the highest amplitude or variance, sorting the points according to this dimension and dividing the points at the median so as to create two new packets. These steps are repeated recursively until the desired number of packets, i.e. the number of colors in the palette, is reached. The color palette is then obtained by calculating the average color of the points contained in each packet.

[0033] For example, the dominant color palette can be determined by a k-means partitioning algorithm, also called the "k-means" algorithm in English terminology. This algorithm consists of partitioning all the points of the initial virtual representation into a predefined number k of distinct packets, so as to minimize the variance within the packets. Each packet is then represented by its average color, thus forming the color palette.

[0034] Other data partitioning or clustering algorithms such as hierarchical partitioning or density partitioning, also called DBSCAN for “Density-based Spatial Clustering of Applications with Noise” in English terminology, can also be implemented to generate the color palette.

[0035] The sub-step of associating each point of the initial virtual representation with the closest dominant color may comprise a sub-step of determining a difference between the initial color associated with each point of the initial virtual representation and the dominant colors.

[0036] This difference, commonly called delta E (AE) can be determined in several ways.

[0037] For example, it can be calculated according to the formula Delta E76 (or AE76), which corresponds to the simple Euclidean distance in the CIELAB or CIE L*a*b color space described by the International Commission on Illumination (CIE) in 1976.

[0038] For example, it can be determined according to the Delta E2000 (or AE00) formula described by the International Commission on Illumination in 2000. The use of this formula is particularly advantageous because it makes it possible to obtain a delta E deviation value more consistent with the perception of the human eye.

[0039] The quantifying step may further comprise the sub-steps of: • determine a gap between the dominant colors of the quantified virtual representation, • if the difference between two dominant colors is less than a predetermined threshold value, replace in the quantified virtual representation the dominant color least represented in the quantified virtual representation among said two dominant colors by the dominant color most represented in the quantified virtual representation among said two dominant colors.

[0040] The threshold value is for example chosen in such a way that if the difference between two predominant colors is less than this threshold value, the colors are sufficiently close so that the original appearance of the interface remains unchanged, whether one or the other color is used.

[0041] Thus, it is possible to further reduce the number of colors of the quantized virtual representation, and therefore to facilitate the manufacture of the translucent opacifying layer, without impacting the original appearance of the interface.

[0042] By retaining the color most represented in the quantified virtual representation among said two dominant colors, the impact on the original appearance of the translucent interface is limited by maintaining the predominance of the main shade, which helps to preserve the initial visual impression of the translucent interface despite the simplification of the color palette.

[0043] It is also possible to keep the lightest color in the quantized virtual representation among the dominant colors.

[0044] Thus, the quantifying step may further comprise the sub-steps of: • determine a gap between the dominant colors of the quantified virtual representation • if the difference between two dominant colors is less than a predetermined threshold value, replace in the quantified virtual representation the darkest dominant color among these two dominant colors by the lightest dominant color among these two dominant colors.

[0045] By retaining the lightest color in the quantified virtual representation among said two dominant colors, the impact on the original appearance of the translucent interface is also limited, because the lighter colors are intrinsically less impactful and alter the overall appearance less than darker colors, thus allowing satisfactory preservation of the original appearance of the translucent interface.

[0046] The predetermined threshold value may be less than or equal to a difference of 20, calculated according to the formula Delta E2000. The Applicant has found that when the difference is equal to or below this value, the colors are close enough that the original appearance of the translucent interface remains unchanged, or at least that the human eye does not perceive the difference, whether one or the other color is used.

[0047] For example, the translucent opacifying layer may have a substantially uniform color over its entire surface.

[0048] For the purposes of this description, a layer is considered to have a substantially homogeneous color if the colorimetric variations among the colors present remain within a colorimetric margin, i.e. a delta E deviation, less than 5, determined according to the formula Delta E2000.

[0049] The manufacturing method may further comprise, before the reproduction step, the steps of: • provide a map of light transmission levels of the translucent interface, each point of the map being associated with a light transmission level, • select a determined overall light transmission level corresponding to a light transmission level obtained on at least part of the translucent interface when the opacifying layer is superimposed on the translucent interface, said determined overall light transmission level being greater than or equal to the lowest light transmission level of said mapping, • modify a parameter of the opacifying layer to adjust a light transmission level of the translucent opacifying layer so as to obtain said determined overall transmission level.

[0050] These steps make it possible, when the translucent interface made of non-homogeneous material has irregularities in the level of light transmission, for example due to intrinsic variations in the material, to harmonize the level of transmission. light transmission of the interface by adjusting one or more parameters of the translucent opacifying layer. It is thus possible to obtain an overlay where the level of light transmission is made homogeneous and continuous over at least part of the interface.

[0051] The translucent opacifying layer may also have a substantially constant level of light transmission.

[0052] If the translucent opacifying layer has several colors, each zone associated with a color may have a substantially constant level of light transmission. However, the zones may not have the same transmission levels.

[0053] For the purposes of this description, a layer is considered to have a substantially constant level of light transmission if the variations in level of light transmission remain within a range of 20%.

[0054] The translucent opacifying layer may comprise at least one opaque or translucent portion with a first level of light transmission and a second translucent portion having a second level of light transmission, the first portion defining a predetermined pattern, and the first level of light transmission being lower than the second level of light transmission.

[0055] In other words, the first portion has a lower light transmission level than the second portion of the translucent opacifying layer so that when the light source of the light display device is in its lit state, the pattern defined by the first portion can be distinguished by a user on the display face. The first portion then makes it possible to mask, partially or totally, the light source. The second portion may have a substantially constant light transmission level.

[0056] The reproducing step may comprise a sub-step of screen printing or digital printing of a translucent colored ink on the support.

[0057] The ink may be a thermoformable ink. This is advantageous when the support is flexible and / or has curved shapes.

[0058] The support may be a face of the translucent interface, for example the rear face, opposite the display face.

[0059] Alternatively, the support may be an additional layer, called a support layer. The support may be transparent or translucent.

[0060] The invention also relates, according to a second aspect, to a luminous display device comprising a translucent interface made of non-homogeneous material and a light source configured to illuminate the translucent interface, characterized in that it comprises a translucent opacifying layer manufactured according to the method described above and superimposed on the translucent interface layer.

[0061] For example, the translucent opacifying layer is disposed between the translucent interface and the light source.

[0062] The translucent opacifying layer may comprise a rear face opposite the display face, the support being formed by the rear face of the translucent interface.

[0063] The translucent opacifying layer may comprise at least one opaque or translucent portion with a first level of light transmission and a second translucent portion having a second level of light transmission, the first portion defining a predetermined pattern, and the first level of light transmission being lower than the second level of light transmission.

[0064] Alternatively, the luminous display device may comprise a masking layer comprising opaque portions and transparent or translucent portions delimiting patterns or pictograms.

[0065] The masking layer is for example arranged between the translucent opacifying layer and the translucent interface.

[0066] For example, the masking layer is arranged in contact with the translucent interface, i.e. against the rear face of the translucent interface. This allows better resolution of the backlit patterns.

[0067] The masking layer may be formed by printing an opaque or translucent ink on the back side of the translucent interface or on an additional transparent or translucent layer.

[0068] The masking layer may meet the same color constraints as the translucent opacifying layer, in order to preserve the original appearance of the non-homogeneous material of the translucent interface, for example when the masking layer is located directly against the rear face of the translucent interface.

[0069] The non-homogeneous material may be a lignocellulosic material, such as wood or flax.

[0070] The light source may comprise at least one of: an LED, an LED screen, an LCD or TFT screen, and a projector.

[0071] The luminous display device may comprise a capacitive or resistive film disposed between the translucent opacifying layer and the light source. Such a layer makes it possible, for example, to add a touch functionality to the luminous display device.

[0072] For example, the translucent opacifying layer and / or the opaque masking layer may be disposed on the capacitive or resistive film.

[0073] The capacitive or resistive film may be formed by printing a conductive and / or dielectric ink onto another support, such as an additional translucent or transparent layer or onto the back face of the interface.

[0074] Alternatively, the masking layer may be disposed on the display face of the translucent interface.

[0075] The light display device may include a radar sensor configured to detect movement through at least the translucent interface.

[0076] The radar sensor may be arranged between the light source and the translucent interface and arranged so as to be able to detect movement at a predefined distance from the display face, for example at a distance of the order of a few centimeters.

[0077] The light display device may comprise a detector of the radio-identification and near-field communication type, or NFC for "Near-Field Communication" in English terminology. This may in particular be used in applications implementing communication between two devices, such as a banking transaction. In particular, the light display device could be used as a "contactless" payment terminal.

[0078] A suitable antenna may for example be printed or arranged on the rear face of the translucent interface.

[0079] The light display device may comprise an additional layer for diffusing light, arranged between the light source and the translucent interface. Such a layer makes it possible to have homogeneous illumination on the display face. In addition, this layer may serve as a support for the various prints described above.

[0080] The light display device may comprise a light guiding element disposed between the light source and the interface layer so as to delimit an illumination zone. Such an element makes it possible to improve the transmission of light towards the display face.

[0081] The light display device may include a reflector and the light source may be configured to directly illuminate the reflector, the reflector being arranged to reflect light emitted by the light source toward the translucent interface. Pre-reflecting light off the reflector avoids direct illumination and light hot spots on the surface, thereby providing homogeneous illumination and a more compact light display device.

[0082] The display face may be covered with a coating, such as an anti-UV coating, a protective varnish capable of resisting abrasion or certain chemical compounds, such as cleaning products or perfume.

[0083] The display device may include one or more adhesive layers. For example, the illuminated display device may include an adhesive layer between the translucent interface and the translucent opacifying layer and / or an adhesive layer between the translucent opacifying layer and the masking layer and / or an adhesive layer between the translucent opacifying layer or the masking layer and the additional layer for diffusion and / or an adhesive layer between one of the previous layers and the light source.

[0084] The adhesive layer(s) may be transparent.

[0085] The luminous display device may comprise, instead of or in addition to the adhesive layers, mechanical holding elements for holding the various parts and / or layers of the luminous display device in place. For example, at least some of the parts and / or layers of the device may be assembled by screwing, clipping, gluing or overmolding.

[0086] The luminous display device can be used in very diverse fields of application, since it makes it possible in particular to camouflage human-machine interfaces while retaining the initial appearance of the non-homogeneous material used, such as a lignocellulosic material. Thus, the luminous display device makes it possible to create a decorative surface capable of transmitting light.

[0087] For example, the light display device can be used in so-called consumer electronics applications. This includes, for example, but is not limited to, a screen, a tablet, a smartphone or a connected watch.

[0088] The light display device can also be used in fields related to mobility.

[0089] The light display device can in particular be used in automobiles, for example by being integrated into a dashboard, a door, a charging station for electric vehicles,

[0090] The luminous display device can in particular be used in nautical transport, as an on-board instrument, cabin element, or yacht interior.

[0091] The light display device can in particular be used in the aeronautical field, as an interior element of airliners or private jets.

[0092] The light display device can in particular be used in the field of cycling or similar such as scooters, by being directly integrated on the latter or on related elements such as a self-service bicycle terminal, an accessory such as a counter or a GPS.

[0093] The light display device can also be used for the design of human-machine interfaces in the field of household appliances, for example control of a household appliance, such as a dishwasher, a refrigerator, cooking plates, etc.

[0094] The light display device can also be used for the design of human-machine interfaces in the field of home automation, for example for controlling a thermostat, an intercom, etc.

[0095] The light display device can also be used in the building and housing sector, for example for ambient lighting or for integrating a screen in a panel of the material continuously, particularly in public spaces, such as an elevator, a parking lot, etc. In particular, the illuminated display device can be used for public display and signage, such as a backlit billboard, a traffic sign, an urban advertising board, etc.

[0096] The light display device can also be used in the field of interior design, for the integration of light signals continuously in a panel. BRIEF DESCRIPTION OF THE FIGURES

[0097] Other advantages, aims and particular characteristics of the present invention will emerge from the following non-limiting description of at least one particular embodiment of the devices and methods which are the subject of the present invention, with reference to the appended drawings, in which:

[0098] [Fig.l] is a schematic sectional view of a light display device according to one embodiment of the invention.

[0099] [Fig.2] is a top view of the light display device of [Fig.l] in which the light source is in an illuminated state.

[0100] [Fig.3] is similar to [Fig.2] with the light source in an off state.

[0101] [Fig.4] is a block diagram showing steps of a method of manufacturing a translucent opacifying layer configured to be superimposed on a translucent interface of non-homogeneous material in a luminous display device, according to an embodiment of the invention.

[0102] [Fig.5] is a block diagram showing sub-steps of a step of providing an initial virtual representation of the manufacturing process of [Fig.4].

[0103] [Fig.6] is a block diagram showing substeps of a quantifying step of the manufacturing process of [Fig.4].

[0104] [Fig.7] is a block diagram showing sub-steps of a step of providing a map of the manufacturing process of [Fig.4].

[0105] [Fig.8] is a block diagram showing sub-steps of a step of providing a map of the manufacturing process of [Fig.4].

[0106] [Fig.9] shows an example of an initial virtual representation of a display face of a luminous display device.

[0107] [Fig. 10] represents a color palette determined from the initial virtual representation of [Fig. 10].

[0108] [Fig. 11] is a quantized virtual representation of the initial virtual representation of [Fig.9].

[0109] [Fig.12] shows the quantized virtual representation of [Fig.10], after an additional step in which colors in the quantized virtual representation of [Fig. 10] have been replaced by the most represented color in that representation.

[0110] [Fig. 13] is a block diagram showing steps of an alternative method of manufacturing a translucent opacifying layer configured to be superimposed on a translucent interface of non-homogeneous material in a luminous display device. DETAILED DESCRIPTION OF THE INVENTION

[0111] Figures 1 to 3 schematically represent a luminous display device 1 according to an embodiment of the invention.

[0112] As visible in [Fig.l], the luminous display device 1 comprises a translucent interface 2 made of non-homogeneous material, a light source 3 configured to illuminate the translucent interface 2, a translucent opacifying layer 4 arranged between the translucent interface 2 and the light source 3, a substrate layer 7 supporting the light source 3 and a capacitive layer 8 arranged between the substrate layer 7 and the translucent opacifying layer 4.

[0113] The luminous display device 1 is formed by a stack of these different layers.

[0114] These layers, namely the translucent interface 2, the translucent opacifying layer 4, the light source 3, the substrate layer 7 and the capacitive layer 8, may have different thicknesses, although in the figure, they have substantially similar thicknesses.

[0115] The translucent interface 2 here has the shape of a substantially flat plate or sheet, having a first face 5, called the display face, and a second face 6, called the rear face, opposite the first face 5.

[0116] Of course, the translucent interface 2 is not limited to this shape and may, for example, have one or more curvatures.

[0117] In the example shown, the translucent interface 2 is a translucent sheet of wood that has been partially delignified and impregnated with a resin.

[0118] The translucent interface layer 4 is here formed by printing a translucent colored ink on the rear face 6 of the translucent wood sheet 2.

[0119] The light source 3 is configured to take an off state and an on state.

[0120] The light source 3 here comprises several LEDs, not shown in detail.

[0121] When the LEDs 3 are in their off state, they do not emit light, and it is not possible for a user to distinguish the LEDs, the substrate layer 7 or other components arranged on the side of the rear face 6 of the translucent interface 2 from the display face 5.

[0122] Indeed, a part of the light rays coming from outside the light display device 1, represented by dotted arrows in [Fig.l], and meeting the display face 5 is reflected by the display face 5, while the other part of these light rays passes through the translucent wooden sheet 2 and is reflected by the translucent colored ink layer 4.

[0123] The intrinsic patterns of the wood also contribute to camouflaging the components arranged on the side of the rear face 6 of the translucent wood sheet 2.

[0124] When the LEDs 3 are in their on state, they emit light.

[0125] The light emitted by the LEDs 3 thus passes through the translucent colored ink layer 4 and the translucent wooden sheet 2, so as to be visible on the display face 5.

[0126] [Fig.2] is a top view of the light display device 1 showing the display face 5 of the translucent wooden sheet 2 when the LEDs 3 are in their illuminated state.

[0127] In the example illustrated, the luminous display device 1 is configured to display on the display face 5 one of the numbers from 1 to 9 surrounded by a circle, and thus forms with the capacitive film 8 a numeric keypad.

[0128] In particular, the translucent colored ink layer 4 here comprises opaque parts and translucent parts (not shown) defining the surrounded numbers.

[0129] The opaque portions may be translucent, but with a lower level of light transmission than the translucent portions, so that the contrast between the circled digits and the rest of the display face is sufficient for a user to detect the circled digits.

[0130] Of course, other information may be displayed on the display face, depending on the light source 3 or the patterns defined by the translucent colored ink 4. The layer of translucent colored ink 4 may, for example, be devoid of an opaque part and the light source 3 may be a screen. The information displayed then depends in this case solely on the information displayed by the screen.

[0131] [Fig.3] is a top view of the light display device 1 showing the display face 2 of the translucent wooden sheet 2 when the LEDs 3 are in their off state.

[0132] In this state of the LEDs 3, only the wood pattern is visible. It is not possible to distinguish the circled numbers or the light source 3 through the translucent interface 2 and the translucent opacifying layer 4.

[0133] Furthermore, the translucent colored ink layer 4 is chosen in such a way that the natural appearance of the wood is preserved. This essentially depends on the color of the translucent colored ink used.

[0134] Thus, the display device 1 is configured so that, when the light source 3 is in its on state, information is visible on the display face 5, and so that, when the light source 3 is in an off state, neither the information nor the light source 3 are visible through the translucent wooden sheet 2 from the display face 5.

[0135] We will now describe, with reference to FIGS. 4 to 8, a method 100 for manufacturing the translucent opacifying layer according to an exemplary implementation of the invention.

[0136] As visible in [Fig.4], the manufacturing method 100 comprises a step of providing an initial virtual representation 110 of the display face of the translucent interface layer.

[0137] The virtual representation comprises a plurality of points, each point being associated with an initial color.

[0138] With reference to [Fig.5], the step of providing the initial virtual representation 110 comprises a sub-step of capturing 111 an image of the translucent interface layer or of reconstructing a plurality of point measurements.

[0139] The manufacturing method 100 comprises a step of quantifying 120 the initial colors of the initial virtual representation so as to obtain a quantified virtual representation comprising a determined number of so-called dominant colors less than the number of initial colors of the initial virtual representation.

[0140] With reference to [Fig.6], the quantifying step 120 comprises a sub-step of selecting 121 a determined number of colors. It has been established that by selecting a number of colors between 1 and 4, it is possible to obtain satisfactory preservation of the original appearance of the interface, quickly and using few resources.

[0141] The quantifying step 120 comprises a sub-step of determining 122 a palette of dominant colors from the determined number of colors and the initial colors of the initial virtual representation.

[0142] The sub-step of determining 122 the palette of dominant colors here comprises a sub-step of grouping 123 the initial colors, here by a k-means grouping algorithm.

[0143] The quantifying step 120 comprises a sub-step of associating 124 each point of the initial virtual representation with the closest dominant color in the determined dominant color palette.

[0144] The sub-step of associating 124 each point of the initial virtual representation with the closest dominant color here comprises a sub-step of determining 125 a difference between the initial color associated with each point of the virtual representation initial and the dominant colors, the difference being determined here according to the Delta E2000 formula.

[0145] The quantifying step 120 comprises a sub-step of replacing 126 the initial color of each point of the initial virtual representation by the dominant color with which it has been associated.

[0146] The quantizing step 120 comprises a sub-step of determining a gap 127 between the dominant colors of the quantized virtual representation.

[0147] The difference is determined here according to the Delta E2000 formula, in the CIELAB color space.

[0148] If the difference between two dominant colors is less than a predetermined threshold value, the quantizing step 120 comprises a sub-step of replacing 128 in the quantized virtual representation the least represented or darkest dominant color in the quantized virtual representation among said two dominant colors by the most represented or lightest dominant color in the quantized virtual representation among said two dominant colors.

[0149] The predetermined threshold value is for example less than or equal to 20 in the CIELAB color space. It has been found that when the difference is equal to or below this value, the colors are close enough for the original appearance of the translucent interface to remain unchanged, or at least for the human eye not to perceive the difference, whether one color or the other is used.

[0150] Thanks to this sub-step, it is possible to further reduce the number of colors of the colored translucent opacifying layer without impacting the natural appearance of the translucent interface.

[0151] The manufacturing method 100 comprises a step of providing a map 130 of light transmission levels of the translucent interface, each point of the map being associated with a light transmission level.

[0152] With reference to [Fig.7], the manufacturing method 100 comprises a step of selecting 131 a determined overall light transmission level corresponding to a light transmission level obtained on at least a portion of the translucent interface when the translucent opacifying layer is superimposed on the translucent interface. The determined overall light transmission level is greater than or equal to the lowest light transmission level of the mapping.

[0153] The manufacturing method 100 comprises a step of modifying 132 a parameter of the translucent opacifying filter to adjust a light transmission level of the translucent opacifying layer so as to obtain the determined overall transmission level.

[0154] The manufacturing method 100 comprises a step of reproducing 140 the quantified virtual representation on a support to manufacture the translucent opacifying layer.

[0155] With reference to [Fig.8], the reproduction step 140 comprises a sub-step 141 of printing by screen printing or digital printing of a translucent ink on the support.

[0156] Selecting a number of colors between 1 and 4 during the sub-step of selecting 121 is especially true when the translucent opacifying layer is reproduced by screen printing.

[0157] Indeed, digital printing has the advantage of allowing rapid and resource-efficient manufacturing even with a large number of colors. In other words, a greater number of colors, for example much greater than 4, can be selected when the translucent opacifying layer is reproduced by digital printing.

[0158] Here, the quantized virtual representation is reproduced directly on the rear face of the translucent interface. In other words, the support is here formed by the rear face of the translucent interface.

[0159] Thus, in the manufacturing method 100, the translucent opacifying layer is obtained from a so-called initial virtual representation corresponding to the display face of the translucent interface made of non-homogeneous material.

[0160] The Applicant found that by superimposing a translucent opacifying layer identical to the display face of the interface, the original appearance of the latter was preserved.

[0161] By quantizing the initial virtual representation, the number of colors in this quantized virtual representation is reduced, which facilitates the fabrication of the translucent opacifying layer, and the general appearance of the translucent interface is preserved.

[0162] Here again, the Applicant found that by superimposing a translucent opacifying layer reproducing the general appearance of the display face of the translucent interface, the original appearance of the latter was not altered.

[0163] Thus, the manufacturing method makes it possible to manufacture, in a simple, convenient and economical manner, a translucent opacifying layer which, when superimposed on the translucent interface from which it was manufactured, makes it possible to increase the capacity to camouflage the components arranged in the background, while preserving the original appearance of this translucent interface.

[0164] Figures 9 to 12 show an example of implementation of the manufacturing method according to the invention, in which the translucent interface is a translucent wooden sheet having been partially delignified and impregnated with a resin.

[0165] [Fig.9] is an initial virtual representation 201 of the display face of the translucent wooden sheet, corresponding to the display face of the luminous display device. This initial virtual representation 201 was obtained here by capturing an image of the translucent interface using a photographic camera.

[0166] [Fig. 10] represents a palette of dominant colors 202 determined from a determined number of colors, here equal to three, and the initial colors of the initial virtual representation 201 of [Fig.9].

[0167] The dominant colors were determined here using the ColorThief software library, which generally uses the "median eut" algorithm.

[0168] Each color in the palette 202 is here associated with a number. The color associated with the number 1, the leftmost in the figure, corresponds to the average color of the points contained in the packet containing the most points, while the color associated with the number 3, the rightmost in the figure, corresponds to the average color of the points contained in the packet containing the fewest points.

[0169] [Fig. 11] is a quantized virtual representation 203 of the display face of the translucent interface, from the dominant colors of the color palette 202 illustrated in [Fig. 10].

[0170] In particular, each point of the initial virtual representation 201 is associated with the closest dominant color in the dominant color palette 202, and the initial color of each point of the initial virtual representation 201 is replaced by the dominant color with which it has been associated.

[0171] The color of the color palette 202 associated with the number 1 is therefore the most represented color in the quantized virtual representation 203, while the color of the color palette 202 associated with the number 3 is the least represented color in the quantized virtual representation 203.

[0172] Note that the color associated with the number 3 is the lightest color among the colors in the color palette 202.

[0173] At this stage, it is possible to reproduce the quantified virtual representation 203 on a support to manufacture the translucent opacifying layer.

[0174] As seen in [Fig. 11], the quantized virtual representation 203 retains the main patterns of the initial virtual representation 201 while significantly reducing the number of colors.

[0175] It is possible to further reduce the number of colors of the quantized virtual representation 203, while retaining the original appearance of the translucent interface.

[0176] [Fig. 12] is a quantized virtual representation 204 which corresponds to the quantized virtual representation 203 of [Fig. 11], but in which the least represented dominant colors in this quantized virtual representation 203, namely the colors associated with the numbers 2 and 3 in the color palette 202 of the [Fig.l 1], have been replaced by the dominant color most represented in said quantified virtual representation 203, namely the color associated with the number 1 of [Fig.11].

[0177] The colors associated with the numbers 2 and 3 have here been replaced by the color associated with the number 1 because the difference determined between the colors associated with the numbers 1 and 2 and between the colors associated with the numbers 1 and 3 is less than a predefined threshold, here equal to 20 in the CIELAB color space.

[0178] Thus, a translucent opacifying layer made from the quantized virtual representation 204 of [Fig. 12] will not impact the natural appearance of the translucent interface because, as explained previously, it has been found that when the difference is equal to or below this value, the colors are close enough that the original appearance of the translucent interface remains unchanged, or at least that the human eye does not perceive the difference, whether one or the other color is used.

[0179] In the example illustrated in [Fig. 12], the quantified virtual representation 204 has a homogeneous color over its entire surface, and is thus relatively easy and economical to manufacture.

[0180] Of course, it is possible to reproduce the translucent opacifying layer from this quantified virtual representation 204 with a substantially homogeneous color over its entire surface, that is to say with several colors whose colorimetric variations remain within a colorimetric margin AE of less than 5, and on condition that the colors respect the previous conditions.

[0181] We will now describe, with reference to [Fig. 13], an alternative manufacturing method 300 of the translucent opacifying layer.

[0182] The manufacturing method 300 comprises the steps of: • measuring 301 an average color of a predetermined area on a display face of the translucent interface, the predetermined area comprising several colors, and • apply 302 a color close to the average color uniformly on a support to make the translucent colored layer.

[0183] For example, a single color is applied uniformly to the support.

[0184] For example, a substantially homogeneous color is applied to the support. In other words, several colors can be applied to the support provided that the colorimetric variations among these colors present remain within a colorimetric margin, that is to say a delta E deviation, less than 5, determined according to the formula Delta E2000.

[0185] The predetermined area may be representative of the predominant color(s) across the entire display face of the translucent interface.

[0186] The average color can be measured using a colorimeter, spectrometer, spectroradiometer, integrating sphere or any other device for acquiring colorimetric data.

[0187] The predetermined area may have an area greater than 5mm2. In particular, the predetermined area may have a diameter, a diagonal or a side, between approximately 2 mm and approximately 10 m, for example equal to approximately 3 mm, approximately 8 mm, approximately 11 mm, approximately 12 mm, approximately 30 mm or 50 mm.

[0188] It will be noted that the larger the predetermined area surface area is relative to the surface area of ​​the display face, the more representative the average color measured will be.

[0189] A color is considered close here when its delta E deviation from the average color, determined according to the Delta E2000 formula, is less than 20.

[0190] Indeed, it has been observed that the original appearance of the translucent interface is only very slightly altered when the delta E2000 difference between a color of the display face and the average color measured is less than 20.

[0191] The translucent opacifying layer may comprise at least one opaque or translucent portion with a first level of light transmission and a second translucent portion having a second level of light transmission, the first portion defining a predetermined pattern, and the first level of light transmission being lower than the second level of light transmission.

[0192] The color may be applied to the support as in the method described with reference to Figures 4 to 8, for example by screen printing or digital printing, directly on the back face of the translucent interface or on a separate support.

[0193] The translucent opacifying layer here has only one color, which makes its manufacture easy and relatively quick. The process of determining the color of this layer is also relatively simple and quick.

[0194] Thus, this manufacturing method makes it possible to manufacture, in a simple, convenient and economical manner, a translucent opacifying layer which, when superimposed on the translucent interface from which it was manufactured, makes it possible to increase the capacity to mask the components arranged in the background, while preserving the original appearance of this translucent interface.

Claims

Claims

1. A method of manufacturing (100) a translucent opacifying layer configured to be superimposed on a translucent interface made of non-homogeneous material in a luminous display device, comprising the steps of: - providing (110) an initial virtual representation of a display face of the translucent interface, the initial virtual representation comprising a plurality of points, each point being associated with an initial color, - quantifying (120) the initial colors of the initial virtual representation so as to obtain a quantified virtual representation comprising a determined number of so-called dominant colors less than the number of initial colors of the initial virtual representation, and - reproducing (140) the quantified virtual representation on a support to manufacture the translucent opacifying layer.

2. Method according to claim 1, characterized in that the quantifying step (120) comprises the sub-steps of: - selecting (121) a determined number of colors, - determining (122) a palette of dominant colors from the determined number of colors and the initial colors of the initial virtual representation, - associating (124) each point of the initial virtual representation with the dominant color closest to the initial color of this point in the determined palette of dominant colors, and - replacing (126) the initial color of each point of the initial virtual representation with the dominant color with which it has been associated.

3. Method according to claim 2, characterized in that the sub-step of associating (124) each point of the initial virtual representation with the closest dominant color comprises a sub-step of measuring (125) a difference between the initial color associated with each point of the initial virtual representation and the dominant colors.

4. Method according to one of claims 2 or 3, characterized in that the sub-step of determining (122) the palette of dominant colors comprises a sub-step of grouping (123) the initial colors by a k-means grouping algorithm.

5. Method according to any one of claims 1 to 4, characterized in that the quantizing step (120) further comprises the sub-steps of: - determining (127) a difference between the dominant colors of the quantized virtual representation, and - if the difference between two dominant colors is less than a predetermined threshold value, replacing (128) in the quantized virtual representation the least represented dominant color in the quantized virtual representation among said two dominant colors by the most represented dominant color in the quantized virtual representation among said two dominant colors.

6. Method according to any one of claims 1 to 4 characterized in that the quantizing step (120) further comprises the sub-steps of: - determining (127) a difference between the dominant colors of the quantized virtual representation, and - if the difference between two dominant colors is less than a predetermined threshold value, replacing in the quantized virtual representation the darkest dominant color among these two dominant colors by the lightest dominant color among these two dominant colors.

7. Method according to one of claims 5 or 6, characterized in that the predetermined threshold value is less than a deviation of 20, determined according to the formula Delta E2000.

8. Method according to any one of claims 1 to 7, characterized in that it further comprises, before the step of reproducing (140), the steps of: - providing a map (130) of light transmission levels of the translucent interface layer, each point of the map being associated with a light transmission level, - selecting (131) a determined overall light transmission level corresponding to a light transmission level obtained on at least a part of the translucent interface when the translucent opacifying layer is superimposed on the translucent interface, said determined overall light transmission level being greater than or equal to the lowest light transmission level of said map, - modifying (132) a parameter of the translucent opacifying layer to adjust a light transmission level of said translucent opacifying layer so as to obtain said determined overall transmission level.

9. A method according to any one of claims 1 to 8, characterized in that the translucent opacifying layer comprises a first portion with a first level of light transmission and a second portion having a second level of light transmission, the first portion defining a predetermined pattern, and the first level of light transmission being lower than the second level of light transmission.

10. Method according to any one of claims 1 to 9, characterized in that the reproducing step (140) comprises a sub-step of printing (141) by screen printing or digital printing of a translucent colored ink on the support.

11. Method according to any one of claims 1 to 10, characterized in that the translucent interface comprises a rear face opposite the display face, the support being formed by the rear face of the translucent interface.

12. Method according to any one of claims 1 to 11, characterized in that the step of providing the initial virtual representation (110) comprises a sub-step of capturing (111) an image of the translucent interface layer or of reconstructing a plurality of point measurements.

13. Luminous display device comprising a translucent interface (2) made of non-homogeneous material and a light source (3) configured to illuminate the translucent interface (2), characterized in that it comprises a translucent opacifying layer (4) manufactured according to a manufacturing method according to any one of claims 1 to 12 and superimposed on the translucent interface (2).

14. A light display device according to claim 13, characterized in that the light source (3) comprises at least one of: an LED, an LED screen, an LCD or TFT screen, and a projector.

15. A light display device according to claim 14, characterized in that the non-homogeneous material is a lignocellulosic material.

Images