Head up display with modular projection system

• US 6,402,321 B1
• Filed: 10/29/1999
• Issued: 06/11/2002
• Est. Priority Date: 10/29/1999
• Status: Expired due to Term

• Current Assignee: Aptiv Technologies Limited (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Harter, Jr., Joseph Edward, Meredith, Marlin D.
• Primary Examiner(s): Adams, Russell
• Assistant Examiner(s): Koval, Melissa J.
• Application Number:
  US09/431,345
• Time in Patent Office: 956 Days
• Field of Search: 353/10, 353/11, 353/12, 353/13, 353/14, 353/69, 340/980, 350/13, 350/630, 350/631, 345/1, 345/7, 345/8, 345/9
• US Class Current: 353/14
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00

Abstract

A head up display system is disclosed that includes a housing, an aspheric reflector, and a modular projection unit. The modular projection unit includes a backlight, a spherical reflector, an infrared mirror, one or more display devices, and cooling apparatus. The backlight has a spherical reflector with inner and outer reflective spherical surfaces and a central opening that is used to recycle light and provide a desired aperture shape. The one or more display devices may be liquid crystal displays, such as active matrix liquid crystal displays. Exemplary cooling apparatus includes an air inlet, a fan and an air outlet that forces air past heat generating components of the projection unit.

Claims

1. A head up display system for use in a vehicle having a windshield, a dashboard, and wherein the head up display system is disposed beneath the dashboard, the system comprising:

(1) a housing;

(2) an aspheric reflector disposed within the housing; and

(3) a projection unit comprising;

one or more image sources comprising;

a backlight;

a spherical reflector disposed adjacent an output of the backlight;

an infrared mirror disposed adjacent an output of the spherical reflector;

a display device disposed adjacent an output of the infrared mirror; and

cooling apparatus for cooling the projection unit.

2. The system recited in claim 1 wherein the projection unit further comprises an air duct that is used to convey air past heat generating components of the projection unit.

3. The system recited in claim 1 wherein the backlight comprises a lamp, a bulb, and a reflector.

4. The system recited in claim 1 wherein the display device comprises a liquid crystal display.

5. The system recited in claim 1 wherein the display device comprises an active matrix liquid crystal display.

6. The system recited in claim 1 wherein the cooling apparatus comprises an air inlet, a fan and air outlet that forces air past heat generating components of the projection unit.

7. A projection unit for use in a head up display system, comprising:

a housing;

one or more image sources disposed in the housing, which one or more image Sources each comprise a backlight, a spherical reflector disposed adjacent an output of the backlight, an infrared mirror disposed adjacent an output of the spherical reflector, and a display device disposed adjacent an output of the infrared mirror; and

cooling apparatus disposed in the housing for cooling the projection unit.

8. The projection unit recited in claim 7 further comprising an air duct that is used to convey air past heat generating components of the projection unit.

9. The projection unit recited in claim 7 wherein the backlight comprises a lamp, a bulb, and a reflector.

10. The projection unit recited in claim 7 wherein the display device comprises a liquid crystal display.

11. The projection unit recited in claim 7 wherein the display device comprises an active matrix liquid crystal display.

12. The projection unit recited in claim 7 wherein the cooling apparatus comprises an air inlet, a fan and air outlet that forces air past heat generating components of the projection unit.