Windshield for head-up display system

• US 20040109251A1
• Filed: 10/20/2003
• Published: 06/10/2004
• Est. Priority Date: 09/28/1989
• Status: Active Grant

• Current Assignee: Glenn E. Freeman
• Original Assignee: Glenn E. Freeman
• Inventors: Freeman, Glenn E.
• Granted Patent: US 6,881,472 B2
• Time in Patent Office: Days
• US Class Current: 359/894
• CPC Class Codes: B32B 17/10036 comprising two outer glass sheets
• CPC Class Codes: B32B 17/10165 Functional features of the laminated safety glass or glazing
• CPC Class Codes: B32B 17/10568 varying in thickness
• CPC Class Codes: B32B 17/1066 imparting a tint in certain regions only, i.e. shade band
• CPC Class Codes: B32B 17/10761 containing vinyl acetal
• CPC Class Codes: B32B 17/10981 Pre-treatment of the layers
• CPC Class Codes: B32B 2457/20 Displays, e.g. liquid crystal displays, plasma displays
• CPC Class Codes: B32B 3/02 characterised by features of form at particular places, e.g. in edge regions non-uniform thickness B32B3/263
• CPC Class Codes: G02B 2027/012 comprising devices for attenuating parasitic image effects
• CPC Class Codes: G02B 2027/0121 Parasitic image effect attenuation by suitable positioning of the parasitic images
• CPC Class Codes: G02B 27/0018 with means for preventing ghost images anti-reflection coatings G02B1/11
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: Y10T 428/187 Continuous sectional layer
• CPC Class Codes: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
• CPC Class Codes: Y10T 428/24479 including variation in thickness
• CPC Class Codes: Y10T 428/24504 Component comprises a polymer [e.g., rubber, etc.]
• CPC Class Codes: Y10T 428/24612 Composite web or sheet
• CPC Class Codes: Y10T 428/24777 Edge feature
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/24967 : Absolute thicknesses specified
• CPC Class Codes: Y10T 428/26 : Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/3163 : Next to acetal of polymerized unsaturated alcohol [e.g., formal butyral, etc.]

Abstract

An automotive transparency includes a first glass ply having a constant thickness, a second glass ply having a constant thickness, and an interlayer having a constant thickness in a first predetermined area and a decreasing thickness in a second predetermined area. The first and second plies are secured together by the interlayer to form a laminate having a first outer major surface, an opposing second outer major surface, a first predetermined area defined by the first predetermined area of the interlayer over which the outer major surfaces are substantially parallel to one another, and a second predetermined area defined by the second predetermined area of the interlayer over which the outer major surfaces are nonparallel to each other such that images reflected off the nonparallel surfaces of the laminate are substantially superimposed over each other to at least reduce double imaging of the reflected image.

Claims

1. An interlayer blank for use with a glass ply in a vehicle windshield, said blank being polyvinylbutyral and having a first portion with a predetermined thickness profile and a second portion with a tapered thickness profile, wherein said predetermined profile is different from said tapered profile.

2. The blank as in claim 1 wherein said first portion extends from a first edge of said blank to said second portion and said second portion extends from said first portion to an opposing edge of said blank.

3. The blank as in claim 2 wherein said thickness of said blank within said tapered profile of said second portion decreases from said first portion to said opposing edge.

4. The blank as in claim 3 wherein said decrease in said thickness in said second portion is generally uniform.

5. The blank as in claim 4 wherein said predetermined thickness profile is a constant thickness.

6. The blank as in claim 5 wherein said constant thickness is between about 0.034 to 0.040 inches and said thickness of said blank along said opposing edge is between about 0.027 to 0.030 inches.

7. The blank as in claim 4 wherein said predetermined thickness profile is a tapered profile different from said tapered profile of said second portion.

8. The blank as in claim 7 wherein said thickness of said blank in said first portion increases from along said first edge to said second portion.

9. The blank as in claim 8 wherein said blank thickness in said first portion increases from between about 0.034 to 0.040 inches along said first edge to between about 0.035 to 0.043 inches at said second portion, and said blank thickness in said second portion decreases from between about 0.035 to 0.043 inches at said first portion to between about 0.029 to 0.036 inches along said opposing edge.

10. The blank as in claim 7 wherein said thickness of said blank in said first portion decreases from along said first edge to said second portion.

11. The blank as in claim 10 wherein said blank thickness in said first portion decreases from between about 0.034 to 0.040 inches along said first edge to between about 0.031 to 0.039 inches at said second portion and said blank thickness in said second portion decreases from between about 0.031 to 0.039 inches at said first portion to between about 0.027 to 0.030 along said opposing edge.

12. The blank as in claim 1 wherein said predetermined thickness profile is a first predetermined profile and further including a third portion having a second predetermined thickness profile wherein said first portion extends from a first edge of said blank to said second portion, said second portion extends from said first portion to said third portion and said third portion extends from said second portion to an opposing edge of said blank.

13. The blank as in claim 12 said thickness of said blank within said second portion decreases from said first portion to said third portion.

14. The blank as in claim 13 wherein said decrease in said blank thickness in said second portion is uniform.

15. The blank as in claim 14 wherein said first thickness profile is a first constant thickness and said second thickness profile is a second constant thickness different from said first constant thickness.

16. The blank as in claim 15 wherein said first constant thickness is between about 0.034 to 0.040 inches, said second constant thickness is between about 0.027 to 0.030 inches and said thickness of said blank within said second portion decreases from said first portion to said third portion.

17. The blank as in claim 14 wherein said first and second thickness profiles are tapered thickness profiles which are tapered at a rate less than that of said tapered profile of said second portion.

18. The blank as in claim 17 wherein said thickness of said blank in said first portion increases from along said first edge to said second portion and said thickness of said blank in said third portion increases from said second portion to said opposing edge.

19. The blank as in claim 18 wherein said blank thickness in said first portion increases from between about 0.034 to 0.040 inches along said first edge to between about 0.035 to 0.043 inches at said second portion, said blank thickness in said third portion increases from between about 0.028 to 0.035 inches at said second portion to between about 0.029 to 0.036 inches along said opposing edge, and said blank thickness in said second portion decreases from said first portion to said second portion.

20. The blank as in claim 17 wherein said thickness of said blank in said first portion decreases from along said first edge to said second portion and said thickness of said blank in said third portion decreases from said second portion to said opposing edge.

21. The blank as in claim 20 wherein said blank thickness in said first portion decreases from between about 0.034 to 0.040 inches along said first edge to between about 0.031 to 0.039 inches at said second portion, said blank thickness in said third portion decreases from between about 0.028 to 0.030 inches along said second portion to between about 0.027 to 0.029 inches along said opposing edge, and said blank thickness in said second portion decreases from said first portion to said third portion.

22. The blank as in claim 1 wherein said blank has a quadrilateral peripheral contour with two opposing sides of arcuate shape.

23. The blank as in claim 22 wherein said blank includes an arcuate gradient color band positioned within said first portion of said blank and substantially parallel to said first edge.

24. A method of making a thermoplastic interlayer having a desired varying thickness profile comprising the steps of:

initially forming said interlayer with a thickness profile greater than said desired profile; and

differentially stretching said interlayer to reduce the thickness of said interlayer such that said thickness of said interlayer corresponds to said desired thickness profile.