Virtual image instrument panel display

• US 5,731,903 A
• Filed: 10/22/1996
• Issued: 03/24/1998
• Est. Priority Date: 11/05/1992
• Status: Expired due to Fees

• Current Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Original Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Inventors: Cook, Lacy G.
• Primary Examiner(s): NGUYEN, THONG Q
• Application Number:
  US08/735,151
• Time in Patent Office: 518 Days
• Field of Search: 359/13-14, 359/364-366, 359/618, 359/629-633, 359/856-861, 359/729, 340/705, 340/980, 345/7-9
• US Class Current: 359/633
• CPC Class Codes: B60K 35/00 Instruments specially adapted for vehicles; Arrangement of instruments in or on vehicles
• CPC Class Codes: G02B 17/0621 off-axis or unobscured systems in which not all of the mirrors share a common axis of rotational symmetry, e.g. at least one of the mirrors is warped, tilted or decentered with respect to the other elements
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/0165 associated with a head-down display
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence

Abstract

A virtual image instrument panel display (20) has a display source (22) and reflective elements (24, 26). The display source (22) generates a beam (28) including an image to be viewed. The reflecting elements (24, 26) receive the beam and provide a virtual image of the image of the beam. The virtual image is focused on a viewing plane at a predetermined and substantial virtual distance away from the user to enable easy eye focus transition between the virtual image and distant objects. The folded nature of the optical system provides for a compact package suitable for installation in an automotive dashboard.

Claims

1. A virtual image instrument panel for a vehicle having a dashboard and an eyebox viewing area, said display comprising:

display source means for generating a beam including information; and

reflecting means, responsive to said beam, for providing a virtual image of the information on a viewing plane at a predetermined virtual distance away from said eyebox viewing area, said reflecting means being housed within said dashboard, said reflecting means including a first non rotationally symmetric aspheric mirror defined by a first Zernike polynomial and a second positive non rotationally symmetric aspheric mirror defined by a second Zernike polynomial which cooperate to provide said virtual image, wherein said beam from said display source means crosses said beam reflected by said second positive aspherical mirror.

2. A virtual image instrument panel display comprising:

display source means for generating a beam including a source image;

a first non rotationally symmetric aspheric mirror defined by a first Zernike polynomial for receiving and reflecting said beam from said display source means; and

a second non rotationally symmetric aspheric mirror defined by a second Zernike polynomial for receiving said beam from said first mirror and reflecting said beam from said first mirror towards an eyebox viewing area, said first and second mirrors cooperating to provide a virtual image of said source image on a viewing plane located at a predetermined virtual distance from said eyebox viewing area, wherein said beam from said display source means crosses said beam reflected by said second mirror.

3. The virtual image instrument panel display according to claim 2 wherein said first mirror is an aspheric mirror.

4. The virtual image instrument panel display according to claim 2 wherein said second mirror is a positive power imaging mirror.

5. The virtual image instrument panel display according to claim 2 wherein said virtual image is at said predetermined virtual distance away from said eyebox viewing area so that eye strain is reduced when a viewer refocuses from viewing said virtual image to viewing surrounding conditions.

6. The virtual image instrument panel display according to claim 5 wherein said predetermined virtual distance is about 80 inches or larger.

7. The virtual image instrument panel display according to claim 2 wherein the beams from said source and second mirror cross at substantially right angles.

8. The virtual image instrument panel display according to claim 2 wherein said eyebox viewing area is approximately 3 inches vertical by 5 inches horizontal.

9. The virtual image instrument panel display according to claim 2 wherein said virtual image instrument panel display is rotatably adjustable about a horizontal axis to provide for different heights of viewers.

10. The display according to claim 2 wherein said beam traveling between said display source means, said first mirror, said second mirror and said eyebox viewing traces an optical path that is configured in substantially the shape of a "4".