Projection arrangement for a head-up display (HUD) with p-polarised radiation and multilayer reflective coating for vehicle glazing

1 . A projection arrangement for a head-up display (HUD), comprising:

a composite pane, which comprises an outer pane and an inner pane joined to one another via a thermoplastic intermediate layer and has an HUD region; and

an HUD projector, which is directed at the HUD region;

wherein

a radiation of the projector is at least partially p-polarised, and

the composite pane is provided with a reflection coating suitable for reflecting p-polarised radiation;

and wherein

the reflection coating comprises n electrically conductive layers based on silver and (n+1) layer modules wherein the (n+1) layer modules and the n electrically conductive layers are arranged alternatingly such that each electrically conductive layer is arranged between two layer modules, where is n a natural number greater than or equal to 1, and

at least one of the (n+1) layer modules is formed as a single layer based on a transparent conductive oxide, and the remaining layer modules, if present, are formed as dielectric layers or layer sequences, and

said single layer based on the transparent conductive oxide (i) is in direct contact with the thermoplastic intermediate layer and with a metallic blocking layer based on a metal or metal alloy having a geometric thickness of at most 0.5 nm, or (ii) is provided between and in direct contact with two of the electrically conductive layers and each of the two of the electrically conductive layers is a layer made of silver, or (iii), n is equal to 1and the single layer based on the transparent conductive oxide is provided between and in direct contact with one of the outer and inner panes and the single electrically conductive layer.

2 . The projection arrangement according to claim 1 , wherein the number n is equal to 1 and said single layer based on the transparent conductive oxide (i) is in direct contact with the thermoplastic intermediate layer and with a metallic blocking layer based on a metal or metal alloy having a geometric thickness of at most 0.5 nm, or (iii) is provided between and in direct contact with one of the outer and inner panes and the single electrically conductive layer.

3 . The projection arrangement according to claim 1 , wherein exactly one of the (n+1) layer modules is formed as a layer based on an electrically conductive oxide, whereas the remaining layer modules are formed as dielectric layers or layer sequences.

4 . The projection arrangement according to claim 1 , wherein a metallic blocking layer having a thickness of less than 1 nm is arranged between at least one electrically conductive layer and an overlying layer module.

5 . The projection arrangement according to claim 1 , wherein a thickness of each electrically conductive layer is at least 7 nm.

6 . The projection arrangement according to claim 1 , wherein a thickness of the at least one layer based on the transparent conductive oxide is from 20 nm to 100 nm.

7 . The projection arrangement according to claim 1 , wherein the transparent conductive oxide is indium tin oxide.

8 . The projection arrangement according to claim 1 , wherein an optical thickness of the dielectric layers or layer sequences is from 50 nm to 150 nm.

9 . The projection arrangement according to claim 1 , wherein the dielectric layers or layer sequences comprise:

a lower anti-reflection layer with a refractive index of at least 1.9 is arranged,

optionally, a refractive-index-enhancing layer with a refractive index of at least 2.1,

optionally, a matching layer.

10 . The projection arrangement according to claim 1 , wherein the reflection coating consists of only the silver layers and the layer modules, as well as optional metallic blocking layers having a thickness of less than 1 nm.

11 . The projection arrangement according to claim 1 , wherein the composite pane with the reflection coating has an integrated light reflection relative to p-polarised radiation of at least 15%, measured with a p-polarised illuminant A light source at an angle of incidence of 65° and a viewing angle of 65° relative to a surface normal of the surface of the inner pane facing away from the intermediate layer.

12 . The projection arrangement according to claim 1 , wherein the composite pane with the reflection coating has a TTS value per ISO 13837 of at most 55%.

13 . The projection arrangement according to claim 1 , wherein the reflection coating is arranged on a surface of the outer pane or the inner pane facing the intermediate layer or within the intermediate layer.

14 . The projection arrangement according to claim 1 , wherein the outer pane is tinted or coloured and has light transmittance of at least 80%.

15 . A method comprising providing a projection arrangement according to claim 1 as an HUD in a vehicle on land, on water, or in the air.

16 . The projection arrangement according to claim 5 , wherein the thickness of each electrically conductive layer is at least 14 nm.

17 . The projection arrangement according to claim 6 , wherein the thickness of the at least one layer based on the transparent conductive oxide is from 30 nm to 80 nm.

18 . The projection arrangement according to claim 9 , wherein

the lower anti-reflection layer is based on silicon nitride,

the refractive-index-enhancing layer is based on a mixed silicon-metal nitride, and

the matching layer is based on zinc oxide.

19 . The projection arrangement according to claim 18 , wherein the refractive-index-enhancing layer is based on mixed silicon-zirconium nitride, mixed silicon-titanium nitride, or mixed silicon-hafnium nitride.

20 . The method according to claim 15 , wherein the vehicle is a motor vehicle, rail vehicle, aircraft, or watercraft.

21 . The projection arrangement according to claim 1 , wherein said single layer based on said transparent conductive oxide is in contact with a metallic blocking layer that is in contact with said at least one of the n electrically conductive layers based on silver.

22 . The projection arrangement according to claim 1 , wherein each of the inner and outer panes is a glass pane.

23 . A projection arrangement for a head-up display (HUD), comprising:

a composite pane, which comprises an outer pane and an inner pane joined to one another via a thermoplastic intermediate layer and has an HUD region; and

an HUD projector, which is directed at the HUD region;

wherein

a radiation of the projector is at least partially p-polarised, and

the composite pane is provided with a reflection coating suitable for reflecting p-polarised radiation;

and wherein

the reflection coating comprises n electrically conductive layers based on silver and (n+1) layer modules wherein the (n+1) layer modules and the n electrically conductive layers are arranged alternatingly such that each electrically conductive layer is arranged between two layer modules, where is n a natural number greater than or equal to 1,

at least one of the (n+1) layer modules is formed as a single layer based on a transparent conductive oxide, and the remaining layer modules, if present, are formed as dielectric layers or layer sequences, and

the number n is equal to 1 and said single layer based on the transparent conductive oxide (i) is in direct contact with the thermoplastic intermediate layer and with a metallic blocking layer based on a metal or metal alloy having a geometric thickness of at most 0.5 nm, or (iii) is provided between and in direct contact with one of the outer and inner panes and the single electrically conductive layer.

24 . The projection arrangement according to claim 23 , wherein each of the inner and outer panes is a glass pane.