METHOD FOR PRODUCING HUD COMPATIBLE WINDSHIELDS AND A WINDSHIELD OBTAINED BY THE METHOD

Abstract

A method for producing a HUD compatible windshield comprising a HUD viewing field provided by an area of a portion of a wedge shaped PVB sheet with an appropriate wedge angle for compensating the double images occurring in reflection at outside and inside surfaces of the windshield, including providing the wedge shaped PVB sheet portion; providing a portion of a plane PVB sheet; assembling the two respective portions of the wedge shaped and plane PVB sheets together; and forming the windshield. The portion of the plane PVB sheet is assembled to the portion of the wedge shaped PVB sheet above the latter in order to be in the upper part of the windshield.

Claims

1. A method for producing a HUD compatible windshield comprising a HUD viewing field provided by an area of a portion of a wedge shaped PVB sheet with an appropriate wedge angle for compensating double images occurring in reflection at outside and inside surfaces of the windshield, comprising: providing said wedge shaped PVB sheet portion; providing a portion of a plane PVB sheet; assembling said two respective portions of the wedge shaped and plane PVB sheets together; and forming the windshield, wherein the portion of the plane PVB sheet is assembled to the portion of the wedge shaped PVB sheet above the latter in order to be in an upper part of the windshield.

2. The method according to claim 1, wherein the assembly of the two wedge and plane PVB sheet portions is laminated between two glass sheets.

3. The method according to claim 1, wherein adjacent edges of the two plane and wedge PVB sheet portions have the same thickness.

4. The method according to claim 1, wherein the assembling of the two portions further comprises forming by ultrasonic welding.

5. The method according to claim 1, wherein the assembling of the two portions further comprises forming by hot air welding.

6. A windshield obtained by the method of claim 1.

7. A windshield obtained by the method of claim 2.

8. A windshield obtained by the method of claim 3.

9. A windshield obtained by the method of claim 4.

10. A windshield obtained by the method of claim 5.

Description

SHORT DESCRIPTION OF THE DRAWINGS

[0025] The invention will be better understood upon reading the following description with reference to the accompanying drawings in which:

[0026] FIG. 1 shows a HUD from the prior art with a wedge shaped windshield;

[0027] FIG. 2 shows an assembly of PVB sheet portions of the windshield of the invention; and

[0028] FIG. 3 shows the thickness profile of the assembly of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

[0029] Referring to FIG. 1, the windshield 2 of a vehicle has a HUD with a wedge angle 1, or in other words a nonzero derivative of the windshield's thickness. In such a HUD, light rays 3 and 4 emitted from the same point in an image source 5 are reflected by a flat mirror 6 and an aspherical mirror 7 before being reflected at the inside surface 8 and the outside surface 9 of the windshield 2. Without an appropriate wedge angle, such reflections would lead to the generation of two separate images for the viewer's eye 10. Thanks to the presence of the wedge angle 1, the HUD allows to having an overlap of these two separate images to form a single virtual image 11.

[0030] FIG. 2 shows an assembly of PVB sheet portions of the windshield 2. The wedge shaped PVB sheet portion 21 covers the lower part of the windshield area and the plane PVB sheet portion 23 covers the upper part of the windshield area, with the zone 22 corresponding to the HUD viewing field of the windshield. Such zone 22 is fully included in the area of the wedge shaped PVB sheet 21 because the wedge angle is needed in this zone for the compensation of the double images in reflection generated by the HUD projector. The line 24 corresponds to the junction between the wedge shaped PVB sheet portion 21 and the plane PVB sheet portion 23. Such junction can be performed here by hot air welding or ultrasonic welding. The assembly of PVB sheet portions has the dimensions of the windshield. The cutting to size of the PVB sheets is performed here before the welding step, separately on each PVB sheet portion. It can also be performed directly on the assembly of PVB sheet portions, after the welding. After the cutting and welding steps, the assembly of PVB sheet portions is here laminated between two glass sheets in order to form the windshield. Such lamination step can be performed with the help of glass vacuum bags, vacuum rings or nip rolls.

[0031] FIG. 3 represents the thickness profile of the assembly of the PVB sheet portions of FIG. 2, from the bottom to the top of windshield. The first part 31 corresponds to the wedge shaped PVB sheet portion 21. The second part 33 corresponds to the plane PVB sheet portion 23. The adjacent edges 35, 36 of the plane PVB sheet portion 23 and of the wedge shaped PVB sheet portions 21 have the same thickness 34. This allows an optimal junction between the plane and wedge shaped PVB sheet portion 31 and 33.