Windshield for head-up display system

• US 5,812,332 A
• Filed: 06/13/1996
• Issued: 09/22/1998
• Est. Priority Date: 09/28/1989
• Status: Expired due to Fees

• Current Assignee: PPG Industries Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Incorporated (Nouryon BV)
• Inventors: Freeman, Glenn E.
• Primary Examiner(s): Shafer, Ricky D.
• Application Number:
  US08/664,033
• Time in Patent Office: 831 Days
• Field of Search: 359/630, 359/894, 156/99, 156/100, 156/101, 156/102, 428/54, 428/55, 428/56, 428/141, 428/156, 428/159, 428/423.1, 428/437, 428/172, 428/192, 428/203, 428/213, 428/215, 428/220, 428/332
• 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

A windshield for a head-up display system has a pair of opposing major surfaces that are nonparallel to one another in selected areas. Light rays directed toward the nonparallel area of the windshield are reflected from the outer and inner major surfaces of the windshield and directed toward the eye of the observer as parallel or superimposed light rays to eliminate ghost images when viewing images projected by the head-up display system through the windshield. The interlayer blank utilized to make the windshield has a non-uniform thickness profile with a tapered thickness positioned in the selected areas of the windshield.

Claims

1. An interlayer blank for securing together glass plies of a vehicle windshield, said blank being polyvinylbutyral and having at least a first portion and a second portion, wherein said first portion has a thickness which changes at a first rate and said second portion has a thickness which decreases at a second rate which is greater than said first rate.

2. A windshield formed of two glass plies secured together by the interlayer blank of claim 1.

3. An interlayer blank for securing together glass plies of a vehicle windshield, said blank being polyvinylbutyral and having a first portion and a second portion, 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, and further wherein said first portion has a thickness which changes from said first edge to said second portion at a first rate, and said second portion has a thickness which decreases from said first portion to said opposing edge at a second rate which is greater than said first rate.

4. The blank as in claim 3 wherein said thickness of said first portion increases from said first edge to said second portion.

5. The blank as in claim 4 wherein said thickness of said first portion increases from between about 0.034 to 0.040 inches at said first edge to between about 0.035 to 0.043 inches at said second portion, and said thickness of 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 at said opposing edge.

6. The blank as in claim 3 wherein said thickness of said first portion decreases from said first edge to said second portion.

7. The blank as in claim 6 wherein said thickness of said first portion decreases from between about 0.034 to 0.040 inches at said first edge to between about 0.031 to 0.039 inches at said second portion, and said thickness of said second portion decreases from between about 0.031 to 0.039 inches at said first portion to between about 0.027 to 0.03 inches at said opposing edge.

8. The blank as in claim 3 wherein said first rate is a first uniform rate and said second rate is a second uniform rate.

9. A windshield formed of two glass plies secured together by the interlayer blank of claim 3.

10. An interlayer blank for securing together glass plies of a vehicle windshield, said blank being polyvinylbutyral and having a first portion, a second portion and a third portion, 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, and further wherein said first portion has a thickness which changes from said first edge to said second portion at a first rate, said second portion has a thickness which decreases from said first portion to said third portion at a second rate, and said third portion has a thickness which changes from said second portion to said opposing edge at a third rate, ad said first and third rate are less than said second rate.

11. The blank as in claim 10 wherein said thickness of said first portion increases from said first edge to said second portion and said thickness of said third portion increases from said second portion to said opposing edge.

12. The blank as in claim 11 wherein said thickness of said first portion increases from between about 0.034 to 0.040 inches at said first edge to between about 0.035 to 0.043 inches at said second portion, and said thickness of 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 at said opposing edge.

13. The blank as in claim 10 wherein said thickness of said first portion decreases from said first edge to said second portion and said thickness of said third portion decreases from said second portion to said opposing edge.

14. The blank as in claim 13 wherein said thickness of said first portion decreases from between about 0.034 to 0.040 inches at said first edge to between about 0.031 to 0.039 inches at said second portion, and said thickness of said third portion decreases from between about 0.028 to 0.030 inches at said second portion to between about 0.027 to 0.029 inches at said opposing edge.

15. The blank as in claim 10 wherein said first rate is a first uniform rate, said second rate is a second uniform rate, and said third rate is a third uniform rate.

16. A windshield formed of two glass plies secured together by the interlayer blank of claim 10.