Windshield for head-up display system

• US 6,636,370 B2
• Filed: 08/21/1998
• Issued: 10/21/2003
• Est. Priority Date: 09/28/1989
• Status: Expired due to Fees

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Freeman, Glenn E.
• Primary Examiner(s): Shafer, Ricky D.
• Application Number:
  US09/138,064
• Publication Number:
  US 20020008926A1
• Time in Patent Office: 1,887 Days
• Field of Search: 359/630, 359/894, 428/156, 428/172, 428/192, 428/215, 428/220, 428/437, 428/159, 428/213, 156/99, 156/100, 156/102, 296/84.1
• 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 automotive transparency for use with a heads-up display system comprising:

a first glass ply;

a second glass ply, the first and second glass plies each having a constant thickness of 0.090 inch and a distance between top of the plies to bottom of the plies of 45 inches;

an interlayer between the first and second glass plies;

the interlayer has a top edge and an opposite bottom edge, the interlayer having a constant thickness of 0.038 inch from the top edge to a distance of 25 inches therefrom defined as a thickness change line and a taper from the thickness change line to the bottom edge of the interlayer, wherein the thickness of the interlayer at the thickness change line is 0.038 inch and at the bottom edge is 0.030 inch.

2. An automotive transparency comprising:

a first glass ply and a second glass ply each having a constant thickness of 0.090 inch and a length of 45 inches; and

an interlayer between the first glass ply and second glass ply and having a constant thickness in a first predetermined area and a varying thickness in a second predetermined area, wherein the first predetermined area of the interlayer is adjacent a top edge of the interlayer and the second predetermined area of the interlayer is adjacent a bottom edge of the interlayer, and the first predetermined area of the interlayer has a constant thickness of 0.038 inch from the top edge to a distance of 25 inches therefrom defined at a thickness change line and the second predetermined area of the interlayer has a taper from the thickness change line to the bottom edge of the interlayer, and the thickness of the interlayer at the thickness change line is 0.038 inch and at the bottom edge is 0.030 inch.

3. The automotive transparency of claim 2 wherein the interlayer is a sheet of polyvinylbutyral.

4. The automotive transparency of claim 2 used in combination with a heads-up display system comprises:

means to project a desired display having first and second light rays, and

means for mounting the automotive transparency and said means to project relative-to one another to direct the first and second light rays toward the second predetermined area.

5. The automotive transparency of claim 2 wherein the interlayer is a plastic interlayer.

11. The interlayer blank of claim 2 wherein the top edge has a shade band.

6. A vehicle windshield for a head-up display comprising:

a first glass ply having a constant thickness;

a second glass ply having a constant thickness; and

a polyvinylbutyral interlayer having a constant thickness in a first predetermined area and a varying thickness in a second predetermined area;

the first glass ply and second glass ply secured together by the interlayer material 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 one another, wherein the windshield has a length of 45 inches, the first predetermined area of the interlayer is adjacent the top of the windshield and extends for a distance of 25 inches and the second predetermined area of the windshield has a wedge-shaped thickness profile.

7. An interlayer blank for securing glass plies together comprising:

a first predetermined area having a constant thickness of 0.038 inch and a second predetermined area having a varying thickness, the interlayer having a top edge and a bottom edge, wherein the first predetermined area of the interlayer is adjacent the top edge and the second predetermined area of the interlayer is adjacent the bottom edge and the first predetermined area of the interlayer has a constant thickness from the top edge to a distance of 25 inches therefrom defined as a thickness change line and the second predetermined area has a taper from the thickness change line to the bottom edge of the interlayer, wherein the thickness of the interlayer at the thickness change line is 0.038 inch and that the bottom edge is 0.030 inch.

8. The interlayer blank of claim 7 wherein the interlayer blank is a sheet of polyvinylbutyral and the second predetermined area viewed in cross-section has a wedged shape.

9. The interlayer blank of claim 7 wherein the interlayer blank is a sheet of polyvinylbutyral.

10. The interlayer blank of claim 7 wherein the interlayer is a sheet of polyvinylbutyral, and the distance between top of the interlayer blank and bottom of the interlayer blank is 45 inches.