COATING STRUCTURE FOR COATING A REFLECTOR FOR USE IN A HEADLIGHT OF A MOTOR VEHICLE

Abstract

A coating structure is provided for coating a reflector for use in a headlamp of a motor vehicle. The coating structure includes a metallic base layer for applying to a substrate which may be a reflective base body. A layer of polytetrafluoroethylene is arranged on the metallic base layer. At least one high-refractive index dielectric layer (H) with a refractive index of ?1.8 in the visible spectral range arranged on the layer of polytetrafluoroethylene. The material of the high-refractive index dielectric layer (H) does not feature any absorption lines in the visible spectral range.

Claims

1. A coating structure for coating a reflector for use in a headlamp of a motor vehicle, the coating structure comprising: a metallic base layer for application to a substrate; a layer of fluorocarbon arranged on the metallic base layer; and at least one high-refractive index dielectric layer (H) with a refractive index of ?1.8 in the visible spectral range arranged on the layer of fluorocarbon, where the material of the high-refractive index dielectric layer (H) does not feature any absorption lines in the visible spectral range.

2. The coating structure in accordance with claim 1, wherein the metallic base layer is fashioned from aluminum, copper, silver or iron.

3. The coating structure in accordance with claim 1, wherein a plurality of high-refractive index dielectric layers (H) and a plurality of low-refractive index dielectric layers (L) with a refractive index of <1.8 in the visible spectral range of a material without absorption lines in the spectral range are arranged on the layer of fluorocarbon, where the high-refractive index dielectric layers (H) and the low-refractive index dielectric layers (L) are arranged on top of each other.

4. The coating structure in accordance with claim 1, wherein at least one high-refractive index dielectric layer (H) is a metal oxide.

5. The coating structure in accordance with claim 1, wherein a low-refractive index layer (L) with a refractive index in the visible spectral range of <1.8 is fluorocarbon and/or hexamethyldisiloxane.

6. The coating structure in accordance with claim 1, further including a bonding layer for improving bonding, where the bonding layer is arranged on the metallic layer.

7. The coating structure in accordance with claim 1, wherein the coating structure features a reflectivity in the visible spectral range of >94%.

8. The coating structure in accordance with claim 1, wherein the layer thickness of the dielectric layers (H, L) is between 10 and 300 nm.

9. The coating structure in accordance with claim 1, wherein the layer thickness of the dielectric layers (H, L) differ at least partially from each other, where the layer thickness of the high-refractive index dielectric layer (H) is less than the layer thickness of the low-refractive index dielectric layer (L).

10. The coating structure in accordance with claim 1, wherein the coating structure is manufactured at least partially by a vapor deposition method.

11. A system comprising a substrate and a coating structure in accordance with claim 1 which is arranged on the substrate.

12. A reflector for use in a headlamp of a motor vehicle, the headlamp comprising a coating structure in accordance with claim 1.

13. A motor vehicle with a headlamp, the headlamp including a reflector comprising a substrate and a coating structure in accordance with claim 1 which is arranged on the substrate.

14. A method of producing a coating structure comprising the steps: applying a metallic base layer to a substrate, applying a layer of fluorocarbon to the metallic base layer, applying a high-refractive index dielectric layer with a refractive index of ?1.8 in the visible spectral range of a material without absorption lines in the visible spectral range to the layer of fluorocarbon.

15. The method in accordance with claim 14, wherein the applying steps of the metallic base layer and/or the layer of fluorocarbon and/or the high-refractive index dielectric layer is/are performed by a vapor deposition method.

16. The coating structure of claim 3, wherein the where the high-refractive index dielectric layers (H) and the low-refractive index dielectric layers (L) alternate.

17. The coating structure of claim 4, wherein the metal oxide of the at least one high-refractive index dielectric layer (H) is TiO2 or Fe2O3.

18. The coating structure of claim 4, wherein the bonding layer is arranged on the metallic layer between the substrate and the metallic layer.

19. The method of claim 15, wherein the vapor deposition method is a PVD or CVD method.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Reference is now made more particularly to the drawings, which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views.

[0026] FIG. 1 is a schematic representation of an inventive system, comprising a substrate and an inventive coating structure arranged on the substrate according to a first sample embodiment.

[0027] FIG. 2 is a schematic representation of an inventive system comprising a substrate and a coating structure arranged on the substrate according to a further sample embodiment.

[0028] FIG. 3 is a schematic representation of application of the reflectivity in the visible spectral range for an inventive coating structure and a comparative coating structure.

[0029] FIG. 4 is a schematic representation of the individual steps of an inventive method for manufacturing an inventive coating structure.

[0030] FIG. 5 is a schematic representation of a motor vehicle with a headlamp, comprising an inventive coating structure.

DETAILED DESCRIPTION OF THE DRAWINGS

[0031] In the following description regarding some sample embodiments of the invention, the identical reference numbers are also used for the same technical features in different sample embodiments.

[0032] FIG. 1 shows a schematic representation of an inventive system 1, comprising a substrate 6 and a coating structure 2 arranged on the substrate 6 for coating a reflector for use in a headlamp 20 of a motor vehicle 30 according to a first sample embodiment.

[0033] As can be seen from FIG. 1, the coating structure 2 comprises a metallic base layer 8 for application to the substrate 6, a layer 10 of fluorocarbon arranged directly on the metallic base layer 8, and a high-refractive index dielectric layer H with a refractive index of ?1.8 in the visible spectral range arranged on the layer 10 of fluorocarbon, where the material of the high-refractive index dielectric layer (H) does not feature any absorption lines in the visible spectral range.

[0034] To be more precise, a plurality of high-refractive index dielectric layers H and a plurality of low-refractive index dielectric layers L with a refractive index of <1.8 in the visible spectral range of a material without absorption lines in the spectral range are arranged on the layer 10 of fluorocarbon in the present case, where the high-refractive index dielectric layers H and the low-refractive index dielectric layers L are arranged on top of each other preferentially alternating.

[0035] The metallic base layer 8 can be fashioned from aluminum, copper, silver or iron in the present case.

[0036] The high-refractive index dielectric layers H can furthermore take the form of a metal oxide. preferentially the form of TiO.sub.2 or Fe.sub.2O.sub.3.

[0037] The low-refractive index dielectric layers L with a refractive index in the visible spectral range of <1.8 can preferentially take the form of polytetrafluoroethylene and/or hexamethyldisiloxane.

[0038] The layer thickness of the dielectric layers H, L can be for example between 10 and 300 nm, preferentially between 50 and 150 nm, where the layer thickness of the dielectric layers H, L differ at least partially from each other, where the layer thickness of the high-refractive index dielectric layer H is preferentially less than the layer thickness of the low-refractive index dielectric layer L.

[0039] With a coating structure 2 fashioned in the present case by means of a vapor deposition method, preferentially manufactured by means of a PVD or CVD method, it is in particular possible to achieve a reflectivity in the visible spectral range of >94%, preferentially of >95%, in particular of >96%.

[0040] FIG. 2. shows a schematic representation of an inventive system 1, comprising a substrate 6 and a coating structure 2 arranged on the substrate 6 according to a further sample embodiment.

[0041] As can be seen from FIG. 2, the coating structure 2 arranged on the substrate 6 comprises a mere three layers, a metallic base layer 8 of aluminum, a layer 10 of polytetrafluoroethylene arranged on the metallic base layer 8 and a high-refractive index dielectric layer H with a refractive index of ?1.8 in the visible spectral range in the form of a TiO.sub.2 layer arranged on the layer 10 of polytetrafluoroethylene.

[0042] FIG. 3 shows a schematic representation of an application of the reflectivity of an inventive coating structure 2 (solid line) and a comparative coating structure (dashed line) in the visible spectral range.

[0043] In this context, the inventive coating structure 2 comprises an aluminum base layer followed by a polytetrafluoroethylene layer and a high-refractive index dielectric layer H with a refractive index of ?1.8 in the form of a TiO.sub.2 layer. In contrast, the comparative coating structure comprises an aluminum base layer, followed by a hexamethyldisiloxane layer and a high-refractive index dielectric layer H with a refractive index of ?1.8 in the form of a TiO.sub.2 layer.

[0044] As can be seen from FIG. 3, the reflectivity of the inventive coating structure 2 is significantly higher over the entire visible spectral range than the reflectivity of the comparative coating structure and shows a maximum value of approximately 98% in contrast to a mere 96% maximum reflectivity of the comparative coating structure.

[0045] FIG. 4 shows a schematic representation of the individual steps of an inventive method for manufacturing an inventive coating structure 2.

[0046] As can be seen from FIG. 4, the inventive method comprises the steps of applying 100 a metallic base layer 8 to a substrate 6, preferentially to a reflective base body, of applying 200 a layer 10 of polytetrafluoroethylene to the metallic base layer 8 and of applying 300 a high-refractive index dielectric layer 12 with a refractive index of ?1.8 in the visible spectral range of a material without absorption lines in the visible spectral range to the layer 10 of polytetrafluoroethylene.

[0047] The applying 100, 200, 300 of the metallic base layer 8 and/or the layer 10 of polytetrafluoroethylene and/or the high-refractive index dielectric layer 12 can be performed in the present case preferentially by means of a vapor deposition method, preferentially by means of a PVD or CVD method.

[0048] FIG. 5 shows a schematic representation of a motor vehicle 30 with a headlamp 20 or two headlamps 20, each comprising an inventive coating structure 2.

[0049] The coating structure 2 fashioned according to the invention makes it possible in particular by using the coating structure 2 in the reflector of a headlamp 20 to increase in a simple and cost-effective manner the light intensity achievable by means of a headlamp 20.

LIST OF REFERENCE NUMBERS

[0050] 1 Inventive system [0051] 2 Coating structure [0052] 6 Substrate [0053] 8 Metallic base layer [0054] 10 Layer of polytetrafluoroethylene [0055] 20 Headlamp [0056] 30 Motor vehicle [0057] 100 Applying a metallic base layer to a substrate [0058] 200 Applying a layer of polytetrafluoroethylene to the metallic base layer [0059] Applying a high-refractive index dielectric layer to the layer of [0060] 300 polytetrafluoroethylene [0061] H High-refractive index dielectric layer [0062] L Low-refractive index dielectric layer [0063] R Reflectivity [0064] A Wavelength