Method for Producing a Curved Substrate Panel with a Hologram, Resulting Substrate Panel with Hologram and a Laminate Containing Such a Substrate Panel, in Particular a Vehicle Window

Abstract

A method for producing a curved substrate panel with a hologram includes producing a curved substrate panel from plastic by forming, injection moulding or injection-compression molding between a first mold half, which defines a predetermined desired geometry of a substrate surface, and a second mold half removing the first mold half from the second mold half and applying a holographic master to a surface of the first mold half, or of a further mold half fixing the first mold half or further mold half on the second mold half such that an empty gap of a predetermined constant thickness remains between the holographic master and the substrate surface, and filling this gap with a hologram-receiving material; and exposing the hologram-receiving layer formed between the substrate surface and the holographic master with a coherent light for forming a hologram defined by the holographic master.

Claims

1.-7. (canceled)

8. A method of producing a curved substrate pane having a hologram, the method comprising: producing the curved substrate pane from plastic by primary forming, injection molding or injection compression molding between a first mold half that defines a predetermined target geometry of a substrate surface and a second mold half separably fixed to the first mold half; removing the first mold half from the second mold half in which the curved substrate pane remains, and applying a holography master in a form of a thin layer to a surface defining the target geometry in the first mold half or a further mold half; fixing the first mold half or the further mold half having the holography master on the second mold half to leave an empty gap of a predetermined constant thickness between the holography master and the substrate surface, and filling the gap with a hologram recording material; and exposing a hologram recording layer formed thereby between the substrate surface and the holography master with a coherent light to form the hologram, wherein the hologram is defined by the holography master.

9. The method according to claim 8, wherein the hologram is a holographic optical element.

10. The method according to claim 8, wherein the hologram recording material is a liquid photopolymer.

11. The method according to claim 8, wherein the exposing of the hologram recording layer is conducted in a closed state of the mold in which the curved substrate pane is fixed between the mold halves that are fixed to one another.

12. The method according to claim 11, wherein exposure elements are integrated in at least one of the first mold half, the second mold half, or the further mold half, wherein the exposure elements are configured to expose the hologram recording layer with the coherent light to form the hologram defined by the holography master.

13. The method according to claim 12, wherein the exposure elements comprise at least one of optical fibers or optical elements.

14. The method according to claim 8, wherein the curved substrate pane, after the hologram recording material has been introduced into the gap formed between the substrate surface and the holography master, is held or fixed in a hologram recording position with respect to the first mold half or the further mold half, while the second mold half is removed from a reverse side of the curved substrate pane, and the exposing of the hologram recording layer is conducted in the hologram recording position through the curved substrate pane by way of a light source disposed at or behind the reverse side of the curved substrate plane.

15. A curved substrate pane produced by the method according to claim 8.

16. The curved substrate plane according to claim 15, wherein the hologram is a volume hologram.

17. A composite pane comprising: the curved substrate pane according to claim 15 as a first pane of the composite pane; and a second pane bonded to the first pane by a bonding layer, wherein the hologram is formed on a surface of the first pane facing the second pane.

18. The composite pane of claim 17, wherein the bonding layer is composed of PVB.

19. A vehicle comprising: a vehicle windowpane at least partly formed by the composite pane according to claim 17, wherein the first pane is an inner pane of the vehicle windowpane lying closer to or directly adjoining a vehicle interior, and the second pane is an outer pane of the vehicle windowpane lying closer or directly adjoining an exterior environment of the vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG. 1 shows a flow diagram of a method of the type set out herein for producing a curved substrate pane with a hologram.

[0035] FIGS. 2a-2d show schematic lateral cross-sectional views of a curved substrate pane produced by the method of FIG. 1 between two separately removable mold halves by primary forming, injection molding or compression injection molding, with hologram created thereon, by way of elucidation of individual process steps of a specific example.

DETAILED DESCRIPTION OF THE DRAWINGS

[0036] All the different embodiments, variants and specific configuration features, mentioned further up in the description and in the claims that follow, of the method according to the first aspect of the invention for producing a curved substrate pane having a hologram and of the resulting substrate pane, of the pane composite and of the vehicle according to the further aspects of the invention may be implemented in the examples shown in FIGS. 1 to 2d. They will therefore not all be repeated once again hereinafter. The same is correspondingly true of the definitions of terms and effects already specified further up in relation to individual features that are shown in FIGS. 1-2d.

[0037] FIG. 1 shows a flow diagram of the method according to the above first aspect of the invention for producing a curved substrate pane 1 with a hologram created thereon. One possible process sequence is elucidated hereinafter with reference to the specific example illustrated in FIGS. 2a-2d for the second embodiment of the method described further up. The curved substrate pane 1 with hologram which is produced in this example may especially serve as a constituent of a future vehicle windowpane, for example of a windshield of a vehicle (not shown). The hologram may especially be a holographic optical element (HOE) which is to be integrated in the vehicle windshield as an element of a head-up display.

[0038] FIGS. 2a to 2d show, each in highly simplified schematic vertical cross-sectional views, four mutual arrangements, successive in the performance of the process according to FIG. 1, of a curved substrate pane 1 and of a mold used for production of the substrate pane 1 and the hologram, comprising a first mold half 2, an opposite second mold half 3 which is separably fixable thereon, and optionally a further mold half 4 that replaces the first mold half 2 for hologram production.

[0039] In this example, the method according to FIG. 1 begins with a step S1 which is schematically illustrated in FIG. 2a and in which said three-dimensionally curved substrate pane 1 made of plastic is produced by primary forming, injection molding or injection compression molding between the first mold half 2, the surface 5 of which from the mold interior side defines a predetermined curved target geometry of a substrate surface 6 to be equipped with a hologram, and a second mold half 3 which is separably fixed on the first mold half 2 and defines a reverse side 7 of the substrate pane 1 (reverse substrate side) facing away from the substrate surface 6.

[0040] As illustrated in FIG. 2b, the first mold half 2, after completion of the curved substrate pane 1 in the mold, is removed in a further step S2 from the second mold half 3 in which the substrate pane 1 still remains, and in this example is replaced by a further mold half 4 with a holography master 9 integrated in/on the surface 8 on the mold interior side that defines this predetermined target geometry. The holography master 9 takes the form, for example, of a surface hologram, and follows the predetermined target geometry of the surface 8 on the mold interior side. In FIG. 2b, the holography master 9 covers only a subsection of the surface 8 on the mold interior side; alternatively, in the present process, it may also cover the entire surface 8 on the mold interior side in order to produce a hologram that extends over the entire substrate surface 6.

[0041] In this case, the further mold half 4 with the holography master 9 integrated therein is fixed on the second mold half 3 so as to leave an empty gap 10 of a predetermined constant thickness of, for example, about 0.1 mm between the holography master 9 and the substrate surface 6.

[0042] As illustrated in FIG. 2c, in a subsequent step S3, the gap 10 is filled with a hologram recording material, in this example a liquid photopolymer, for example by injection, so as to form a hologram recording layer 11 having a constant layer thickness corresponding to the gap thickness and having full-area contact with the holography master 9 on the substrate surface 6. In this example, the gap 10 and hence also the hologram recording layer 11, purely by way of example, extends over the entire substrate surface 6; alternatively, it may also extend merely over part of the substrate surface 6.

[0043] As illustrated in FIG. 2d, in a subsequent optional step S4, according to said second embodiment of the process, the second mold half 3 is removed from the reverse side 7 of the substrate pane 1, while the substrate pane 1 remains fixed in the hologram recording position established in FIG. 2c with regard to the further mold half 4 and the holography master 9 integrated therein. Subsequently, in a step S5, the exposure of the hologram recording layer 11 with coherent light is conducted in this hologram recording position through the substrate pane 1 by way of a light source 12 disposed behind the reverse side 7 thereof.

[0044] Alternatively, according to the first embodiment of the process as described further up, the optional step S4 can be omitted (which is why it is only shown by dotted lines in FIG. 1), and the exposure of the hologram recording layer 11 in step S5 can be conducted in a closed state of the mold in which the curved substrate pane 1 with the hologram recording layer 11 formed thereon is fixed between the two mold halves 3 and 4 that are fixed to one another according to FIG. 2c, i.e. between the further mold half 4 in which the holography master 9 is integrated and the second mold half 3 in which the substrate pane 1 has been produced and is yet to be removed. In this case, suitable exposure elements (not shown), especially optical fibers such as glass fibers and/or suitable lighting optics of a type known per se, may be integrated in the second mold half 3, these being designed for exposure of the hologram recording layer 11 with a coherent light for formation of a hologram defined by the holography master 9.

[0045] In both embodiments, with the aid of the mold, as described, it is possible in a reliable manner to ensure a hologram recording arrangement required for the present hologram recording method, in which the holography master 9, for the duration of hologram recording, is in full-area contact with the hologram recording layer 11 and a predetermined constant separation between holography master 9 and substrate surface 6 is established with a required accuracy of especially less than 10 micrometers, which corresponds to said constant layer thickness of the hologram recording layer 11.

[0046] The exposure in step S5 and any subsequent fixing with UV light result in curing of the liquid photopolymer. After the described completion of the hologram in the hologram recording layer 11, the holography master 9 is removed again therefrom in a final step S6 by removing the further mold half 4 that bears the holography master 9 from the substrate pane 1. The finished product, after the removal of both mold halves 3 and 4, comprises the curved substrate pane 1 with the hologram recording layer 11, in which the hologram is formed, formed on and bonded to the substrate surface 6.

LIST OF REFERENCE NUMERALS

[0047] 1 curved substrate pane [0048] 2 first mold half [0049] 3 second mold half [0050] 4 further mold half [0051] 5 surface of the first mold half on the mold interior side that defines the predetermined curved target geometry of the substrate surface [0052] 6 substrate surface [0053] 7 reverse side of the curved substrate pane [0054] 8 surface of the further mold half on the mold interior side that defines the predetermined curved target geometry of the substrate surface [0055] 9 holography master [0056] 10 gap [0057] 11 hologram recording layer [0058] 12 light source for coherent light