Glass for autonomous car

Abstract

The invention concerns an automotive glazing comprising (i) at least one glass sheet having an absorption coefficient lower than 5 m.sup.−1 in the wavelength range from 1051 nm to 1650 nm and having an external face and an internal face, and (ii) an infrared filter. According to the present invention, an infrared-based remote sensing device in the wavelength range from 1051 nm to 1650 nm, is placed on the internal face of the glass sheet in a zone free of the infrared filter layer.

Claims

1. A glazing comprising: a glass sheet having an absorption coefficient lower than 5 m.sup.−1 in a wavelength range from 1051 nm to 1650 nm and having an external face and an internal face, and an infrared filter, wherein an infrared-based remote sensing device in the wavelength range from 1051 nm to 1650 nm, is placed on the internal face of the glass sheet in a zone free of the infrared filter layer.

2. The glazing according to claim 1 wherein the glass sheet has an absorption coefficient lower than 1 m.sup.−1.

3. The glazing according to claim 1, wherein the infrared-based remote sensing device is optically coupled to the internal face of the glazing.

4. The glazing according to claim 1, wherein the glazing is a laminated glazing comprising the glass sheet, which is an exterior glass sheet, and an interior glass sheet laminated with at least one thermoplastic interlayer and wherein the exterior and an interior glass sheets are high level of near infrared radiation transmission glass sheets having an absorption coefficient lower than 5 m.sup.−1 and wherein the infrared-based remote sensing device is placed on face 4.

5. The glazing according to claim 1, having a value of visible light transmission that is lower than the glazing's value of near infrared transmission.

6. The glazing according to claim 1, wherein the glass sheet is covered with at least one near-infrared transparent coating that absorbs and/or reflects visible light.

7. The glazing according to claim 1, wherein the glass sheet comprises a content, expressed as the total weight of glass percentages: total iron (expressed as Fe.sub.2O.sub.3) 0.002 to 0.06%; and Cr.sub.2C.sub.3 0.0001 to 0.06%.

8. The glazing, according to claim 1, wherein the glass sheet comprises a content, expressed as the total weight of glass percentages: total iron (expressed as Fe.sub.2O.sub.3) 0.002 to 0.06%; Cr.sub.2O.sub.3 0.0015 to 1%; and Co 0.0001 to 1%.

9. The glazing according to claim 1, wherein the glass sheet comprises a content, expressed as the total weight of glass percentages: total iron (expressed as Fe.sub.2O.sub.3) 0.02 to 1%; Cr.sub.2O.sub.3 0.002 to 0.5%; and Co 0.0001 to 0.5%.

10. The glazing according to claim 1, wherein the glass sheet comprises a content, expressed as the total weight of glass percentages: total iron (expressed as Fe.sub.2O.sub.3) from 0.002 to 1%; Cr.sub.2O.sub.3 0.001 to 0.5%; Co 0.0001 to 0.5%; and Se 0.0003 to 0.5%.

11. The glazing according to claim 1, wherein the infrared filter layer is a multilayer stack comprising: a functional layers of a material reflecting infrared radiation, with n≥1, and n+1 dielectric coatings such that each functional layer is surrounded by dielectric coatings.

12. The glazing according to claim 1, wherein the infrared filter layer is silver-based.

13. The glazing according to claim 1, wherein the infrared filter layer is a coating wherein the zone free infrared filter is provided on which the infrared-based remote sensing device is placed.

14. The glazing according to claim 1, wherein the infrared-based remote sensing device is a LIDAR system based on scanning, rotating, flashing or solid state LiDARs and enabling of 3D mapping the surroundings around the vehicle.

15. The glazing according to claim 1, wherein an anti-reflective coating is provided on a surface of the glazing.

16. The glazing according to claim 1, wherein the glazing is a windshield.

17. The automotive glazing according to claim 1, wherein the infrared filter comprises a coating deposited on the glass sheet.

18. The automotive glazing according to claim 1, wherein the glass sheet has an absorption coefficient lower than 5 m.sup.−1 and greater than 1 m.sup.−1.

19. The automotive glazing according to claim 1, further comprising a second glass sheet laminated to the glass sheet with at least one thermoplastic interlayer, wherein the second glass sheet has an absorption coefficient lower than 5 m.sup.−1.

20. An automotive glazing comprising: a. a first glass sheet having an absorption coefficient lower than 5 m.sup.−1 and greater than 1 m.sup.−1 in a wavelength range from 1051 nm to 1650 nm, b. an infrared filter, c. a thermoplastic interlayer, d. a second glass sheet having an absorption coefficient lower than 5 m.sup.−1 in a wavelength range from 1051 nm to 1650 nm, and e. an infrared-based remote sensing device in a wavelength range from 1051 nm to 1650 nm placed on face 4 of the second glass sheet in a zone free of the infrared filter, wherein the first glass sheet, the second glass sheet, and the thermoplastic interlayer are laminated together.

Description

(1) According to another alternative embodiment, the glass has a composition which comprises a content, expressed as the total weight of glass percentages: total iron (expressed as Fe.sub.2O.sub.3) 0.002-0.06%; and one of the following components: manganese (calculated as MnO) in an amount ranging from 0.01 to 1% by weight; antimony (expressed as Sb.sub.2O.sub.3), in an amount ranging from 0.01 to 1% by weight; arsenic (expressed as As.sub.2O.sub.3), in an amount ranging from 0.01 to 1% by weight, or copper (expressed as CuO), in an amount ranging from 0.0002 to 0.1% by weight.

(2) Such compositions are described in European patent application No. 14 167 942.3, incorporated by reference herein.

(3) According to the present invention, the automotive glazing may be in the form of planar sheets. The glazing may be curved. This is usually the case for automotive glazing as for rear windows, side windows or roofs or especially windshields.

(4) In automotive applications, the presence of high transmission glass sheet in the infrared is not conducive for maintaining thermal comfort when the vehicle is exposed to sunlight. A proposed means of the invention is to provide a glazing with a high selectivity (TL/TE), preferably with a selectivity greater than 1 or greater than 1.3. Thus, to remain under appropriate conditions of energy transmission and thermal comfort, apart from the already specified elements, the glazing according to the invention comprises means to selectively filtering the infrared from sun radiation.

(5) Alternatively, it may be advantageous to use in combination with the glass according to the invention, a filtering layer having an IR transmission lower than 50, 40, 35, 30, 25, 20, 15, 10, 5, 4, 3, 2 or 1%.

(6) Advantageously, the infrared filter is a reflective layer with a multilayer stack comprising n-layer (s) functional (s) based on a material that reflects infrared radiation, with n≥1, and n+1 dielectric coatings such that each functional layer is surrounded by dielectric coatings.

(7) The functional layers, part of the infrared reflecting layers are advantageously formed from noble metal. They can be based on silver, gold, palladium, platinum or their mixture or alloy, but also based on copper or aluminum, alone, alloy or alloy with one or more noble metals. Preferably all the functional layers are based on silver. It is a noble metal that has a very high efficiency of reflection of infrared radiation. It is easily implemented in a magnetron device and its cost is not prohibitive, especially with regard to its effectiveness. Advantageously, the silver is doped with a few percent palladium, aluminum or copper, for example because of 1 to 10% by mass, or can be used a silver alloy.

(8) Dielectrics, transparent coatings, part of infrared reflective layers are well known in the field of films deposited by sputtering. Suitable materials are many and it is not useful to make the full list here. These are generally oxides, oxynitrides or metal nitrides. Among the most common include for example SiO2, TiO.sub.2, SnO.sub.2, ZnO, ZnAlOx, Si.sub.3N.sub.4, AlN, Al.sub.2O.sub.3, ZrO.sub.2, Nb.sub.2O.sub.5, YOx, TiZrYOx, TiNbo.sub.x, HfO.sub.x, MgOx, TaO.sub.x, CrOx and Bi.sub.2O.sub.3, and mixtures thereof. One can also cite the following materials: AZO, ZTO, GZO, NiCrO.sub.x, TXO, ZSO, TZO, TNO TZSO, TZAO and TZAYO. The term AZO relates to a zinc oxide doped with aluminum or a mixed oxide of zinc and aluminum, obtained preferably from a ceramic target formed by the oxide to be deposited, sprayed either neutral or slightly oxidizing atmosphere. Similarly, the ZTO or GZO expressions relate respectively to mixed oxides of titanium and zinc or zinc and gallium, obtained from ceramic targets, either in a neutral or slightly oxidizing atmosphere. The term TXO relates to titanium oxide obtained from a titanium oxide ceramic target. The ZSO term refers to a mixed zinc-tin oxide obtained either from a metal target of alloy deposited in an oxidizing atmosphere or from a ceramic target of the corresponding oxide or neutral atmosphere or slightly oxidizing. TZO TNO TZSO, TZAO or TZAYO expressions relate respectively to mixed titanium zirconium oxides, titanium-niobium, titanium-zirconium-tin, titanium-zirconium-aluminum or titanium-zirconium-aluminum-yttrium, obtained from ceramic targets, either neutral or slightly oxidizing atmosphere. All these above mentioned materials can be used to form the dielectric films used in the present invention.

(9) Preferably, the dielectric coating disposed under one or each functional layer includes, in direct contact with the functional layer or layers, a layer based on zinc oxide, optionally doped for example with aluminum or gallium, or alloy with tin oxide. The zinc oxide can have a particularly favorable effect on the stability and the corrosion resistance of the functional layer, especially when it comes to money. It is also conducive to the improvement of the electrical conductivity of a silver-based layer, and thus obtaining a low emissivity.

(10) The different layers of the stack are, for example, sputtered under reduced pressure magnetron sputtering, in a known magnetron device. The present invention is however not limited to this particular method of layer deposition.

(11) According to a particular embodiment of the invention, these layers of assemblies may be arranged either on a carrier sheet, in particular of PET, inserted in the laminated, either by direct application on the glass sheet.

(12) As an alternative to metal layers on the basis described above, the infrared reflective layer can include a plurality of non-metallic layers, so that it operates as a band pass filter (the band being centered near the region infrared electromagnetic spectrum).

(13) According to a preferred embodiment of the invention, the automotive glazing is a laminated glazing comprising an exterior and an interior glass sheets laminated with at least one thermoplastic interlayer and wherein the exterior and an interior glass sheets are high level of near infrared radiation transmission glass sheets having an absorption coefficient lower than 5 m.sup.−1 in the wavelength range from 1051 nm to 1650 nm. The layer reflecting infrared radiation is then preferably placed on face 2 meaning on the inner face of the first glass sheet which is mounted on the vehicle and being in contact with the external environment.

(14) According to another embodiment of the present invention, the infrared filter is a thermoplastic interlayer absorbing infrared rays. Such thermoplastic interlayer is for example a PVB doped with an ITO.

(15) According to another embodiment of the present invention, the infrared filter is a tinted glass.

(16) According to one embodiment of the present invention, the glass sheet has a value of light transmission lower than the value of infrared transmission. Particularly, according to another embodiment of the present invention, the value of light transmission in the visible range is lower than 10% and the value of near infrared transmission is higher than 50%.

(17) According to another advantageous embodiment of the invention, the glass sheet is covered with at least one IR transparent absorbing (tinted) and/or reflecting coating in order to hide the un-aesthetic element of the sensor from the outside while ensuring a good level of operating performances. This coating may, for example, be composed of at least one layer of black ink having no (or very low) transmission in the visible optical range but having a high transparency in the infrared range of interest for the application. Such ink can be made of organic compounds as, for example, commercial products manufactured by Seiko Advance Ltd. Or Teikoku Printing Ink Mfg. Co. Ltd. that can achieve transmission <5% in the 400-750 nm range and >70% in the 850-1650 nm range. The coating may be provided on face(s) 1 or/and 2 for a single automotive glazing element or on face(s) 1 or/and 4 for a laminated automotive glazing, depending of its durability.

(18) According to another embodiment of the invention, the glass sheet may be covered with a multilayer coating optimized to reflect selectively the visible range while maintaining high IR transmission. Some properties such as observed on Kromatix® product are thus sought. These properties ensure a total low IR absorbance of the complete system when such layer is deposited on adequate glass composition. The coating may be provided on face(s) 1 or/and 2 for a single automotive glazing element or on face(s) 1 or/and 4 for a laminated automotive glazing, depending of its durability.

(19) According to the present invention, a LiDAR instrument is an optoelectronic system composed of at least a laser transmitter, at least a receiver comprising a light collector (telescope or other optics) and at least a photodetector which converts the light into an electrical signal and an electronic processing chain signal that extracts the information sought.

(20) The LiDAR is placed on the internal face of the glass sheet (namely face 2) in case of one glass sheet glazing in a zone free of infrared filter layer.

(21) Preferably, the LiDAR is placed in the upper part of the glazing and more preferably closed to the mirror holder.

(22) According to another embodiment of the present invention, the automotive glazing is a laminated glazing wherein the LiDAR is placed on the internal face of the inner glass sheet namely the face 4 on a zone of the glass sheet wherein the IR-filtering mean is not present.

(23) According to a preferred embodiment of the present invention, the automotive glazing is a windshield. Thus, the infrared-based remote sensing device is placed on face 4 of the windshield on a zone free of infrared reflective layer. Indeed, in case of an infrared reflective coating, a zone free of coating is provided for example by decoating or by masking in a way that the LiDAR is positioned on this area without coating on face 4 (or on face 2 in case of one glass sheet glazing) to insure its functionalities. The coating free area has generally the shape and dimensions of the infrared-based remote sensing device. In case of an infrared absorbing film, the film is cut in the dimensions of the LiDAR that the LiDAR is positioned on this area without film to insure its functionalities.

(24) According to one embodiment of the present invention, the automotive glazing is ultrathin glazing.

(25) Advantageously, the IR-based remote sensing device is optically coupled to the internal face of the glazing. For example, a soft material that fits refractive index of the glass and the external lens of the LiDAR may be used.

(26) According to another advantageous embodiment of the invention, the glass sheet is coated with at least one antireflection layer. An antireflection layer according to the invention may, for example, be a layer based on porous silica having a low refractive index or it may be composed of several layers (stack), in particular a stack of layers of dielectric material alternating layers having low and high refractive indexes and terminating in a layer having a low refractive index. Such coating may be provided on face(s) 1 or/and 2 for a single glazing” or on face(s) 1 or/and 4 for a laminated glazing. A textured glass sheet may be also used. Etching or coating techniques may as well be used in order to avoid reflection.