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EP-4735248-A1 - COMPOSITE PANE COMPRISING A HEATABLE, TRANSPARENT FILM AND A REFLECTIVE LAYER FOR P-POLARISED RADIATION

EP4735248A1EP 4735248 A1EP4735248 A1EP 4735248A1EP-4735248-A1

Abstract

The present invention relates to a composite pane (100) comprising at least, in the following order: an outer pane (1) having an outer surface (I) and an inner surface (II); a first thermoplastic intermediate layer (3); a heatable, transparent film (4); a second thermoplastic intermediate layer (5); an inner pane (2) having an outer surface (III) and an inner surface (IV); and a reflective layer (6) on the outer surface (III) of the inner pane (2) or on the inner surface (IV) of the inner pane (2), wherein the reflective layer (6) is suitable for reflecting p-polarised radiation.

Inventors

  • RASTEGAR, Hadi
  • MOTEMANI SHARABIANI, Yahya
  • GILLESSEN, Stephan
  • HAGEN, JAN

Assignees

  • Saint-Gobain Sekurit France

Dates

Publication Date
20260506
Application Date
20240617

Claims (15)

  1. 1. Composite pane (100), comprising at least in the following order: an outer pane (1) with an outer surface (I) and an inner surface (II), a first thermoplastic intermediate layer (3), a heatable, transparent film (4), a second thermoplastic intermediate layer (5), an inner pane (2) with an outer surface (III) and an inner surface (IV), and a reflection layer (6) on the outer surface (III) of the inner pane (2) or on the inner surface (IV) of the inner pane (2), wherein the reflection layer (6) is suitable for reflecting p-polarized radiation.
  2. 2. Composite pane (100) according to claim 1, wherein the reflection layer (6) is a reflective coating which represents a dielectric layer sequence with alternating refractive indices.
  3. 3. Composite pane (100) according to claim 1 or 2, wherein the heatable, transparent film (4) comprises a polymer film (7).
  4. 4. Composite pane (100) according to one of claims 1 to 3, wherein the heatable, transparent film (4) comprises a metal mesh layer (8).
  5. 5. Composite pane (100) according to claim 4, wherein the metal mesh layer (8) is formed from metal lines (9) and the line width of a metal line (9) is from 1 pm to 7 pm.
  6. 6. Composite pane (100) according to claim 5, wherein the metal lines (9) are arranged in a diamond pattern (10).
  7. 7. Composite pane (100) according to one of claims 1 to 3, wherein the heatable, transparent film (4) comprises a layer with metal nanowires (11), wherein the metal nanowires have a diameter in a range from 10 nm to 100 nm and a length in a range from 5 pm to 30 pm.
  8. 8. Composite pane (100) according to one of claims 4 to 7, wherein the heatable, transparent film (4) comprises a layer with electrically conductive fibers (12) which at least partially covers the metal mesh layer (8) or the layer with metal nanowires (11).
  9. 9. Composite pane (100) according to one of claims 4 to 8, wherein the metal of the metal mesh layer (8) or the layer with metal nanowires (11) is selected from copper or silver.
  10. 10. Composite pane (100) according to one of claims 3 to 9, wherein the polymer of the polymer film (7) comprises polyethylene terephthalate or polycarbonate.
  11. 11. Composite pane (100) according to one of claims 8 to 10, wherein the electrically conductive fibers (12) comprise carbon nanotubes, preferably single-walled carbon nanotubes with a diameter of 0.7 nm to 1.4 nm and a length of 0.3 pm to 3 pm.
  12. 12. Composite pane (100) according to one of claims 1 to 11, wherein the reflection layer (6) is arranged on the inner surface (IV) of the inner pane (2).
  13. 13. Display system (200) for a vehicle, comprising the composite pane (100) according to one of claims 1 to 12, wherein the composite pane (100) has at least one display area (A) and at least one imaging unit (13) which is directed at the display area (A) and irradiates it with p-polarized radiation.
  14. 14. A method for producing a composite pane (100) according to one of claims 1 to 12, wherein at least a) a layer stack is provided which comprises at least in the following order: an outer pane (1) with an outer surface (I) and an inner surface (II), a first thermoplastic intermediate layer (3), a heatable, transparent film (4), a second thermoplastic intermediate layer (5), an inner pane (2) with an outer surface (III) and an inner surface (IV), and a reflection layer (6) on the outer surface (III) of the inner pane (2) or on the inner surface (IV) of the inner pane (2), and b) the layer stack is connected by lamination.
  15. 15. Use of a composite pane (100) according to one of claims 1 to 12 as interior glazing or exterior glazing in a vehicle or a building, in particular as a vehicle pane in means of transport for traffic on land, in the air or on water, in particular in motor vehicles and in particular as a windshield which serves as a projection surface.

Description

Composite pane with heatable, transparent film and reflection layer for p-polarized radiation The invention relates to a composite pane with a heatable, transparent film and a reflection layer for p-polarized radiation, a display system comprising the composite pane, a method for producing the composite pane and the use of the composite pane. Modern vehicles are increasingly being equipped with so-called head-up displays (HLIDs). A projector, typically in the dashboard area, projects images onto the visible area of the windshield, where they are reflected and perceived by the driver as a virtual image (from his perspective) behind the windshield. This means that important information can be projected into the driver's field of vision, such as the current driving speed, navigation or warning information, which the driver can perceive without having to take his eyes off the road. Head-up displays can therefore make a significant contribution to increasing road safety. HUD projectors typically illuminate the windshield at an angle of incidence of about 65%, which is close to the Brewster angle for an air-glass transition (57.2° for soda-lime glass). This circumstance can be exploited to ensure a clear display of the HUD projection: if the HUD projector is operated with p-polarized radiation, the radiation is hardly reflected at the external glass surfaces of the windshield. Instead, the windshield is equipped with a reflective layer that is suitable for reflecting the p-polarized radiation to produce the display image. Since there is only one significant reflection plane, namely the reflective layer, a clear display image is produced without ghost images (or with only weak ghost images that are due to residual reflection at the external glass surfaces if the angle of incidence deviates slightly from the Brewster angle). For example, reference is made to DE102014220189A1, EP3187917B1 and WO2021104800A1. It is desirable to provide a composite pane suitable for HUD projection that can also be heated to prevent fogging of the composite pane or to facilitate de-icing of a frozen composite pane. A transparent, conductive film is known, for example, from WO 2016/172315 A1, WO 2020/102392 A1 and WO 2022/081756 A1. WO 2023/066378 A1 describes a HUD glass that may include an electrically conductive layer. WO 2022/106315 A1 describes a projection arrangement for HUD with p-polarized radiation, which comprises heating wires. WO 2022/050388 A1 describes a laminated glass, wherein a functional layer is arranged between the outer glass pane and the inner glass pane and a binding layer for fixing the functional layer is arranged between the two glass panes. The present invention is based on the object of providing a heatable composite pane with high transmission in the visible spectral range, which is suitable for HUD projection using p-polarized radiation. The object of the present invention is achieved according to the invention by a composite pane according to claim 1. Preferred embodiments emerge from the subclaims. The invention also relates to a display system comprising the composite pane, a method for producing the composite pane and the use of the composite pane as interior glazing or exterior glazing in a vehicle or a building. The composite pane according to the invention comprises at least in the following order: an outer pane with an outer surface and an inner surface, a first thermoplastic intermediate layer, a heatable, transparent film, a second thermoplastic intermediate layer, an inner pane with an outer surface and an inner surface, and a reflective layer on the outer surface of the inner pane or on the inner surface of the inner pane, wherein the reflective layer is suitable for reflecting p-polarized radiation. As described above, the outer pane and the inner pane each have an outside surface, i.e. an outer surface, and an interior surface, i.e. an inner surface, and a circumferential side edge running between them. In the sense of the invention, the outer surface refers to the main surface which is intended to face the outside environment in the installed position. In the sense of the invention, the inner surface refers to the main surface which is intended to face the interior in the installed position. The inner surface of the outer pane and the outer surface of the inner pane face each other in the composite pane according to the invention. The surfaces of the composite pane are typically referred to as follows: The outer surface of the outer pane is called side I. The inner surface of the outer pane is called side II. The outer surface of the inner pane is called side III. The inner surface of the inner pane is called side IV. If the composite pane is intended to separate an interior space from the outside environment in a window opening of a vehicle or a building, the inner pane in the sense of the invention refers to the pane facing the interior space (vehicle interior). The outer pane refers to