Optical: systems and elements – Single channel simultaneously to or from plural channels – By partial reflection at beam splitting or combining surface
Reexamination Certificate
1999-04-29
2001-07-17
Epps, Georgia (Department: 2873)
Optical: systems and elements
Single channel simultaneously to or from plural channels
By partial reflection at beam splitting or combining surface
C359S631000, C359S633000
Reexamination Certificate
active
06262848
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention relates to optical systems, and more particularly to head-up displays.
BACKGROUND OF THE INVENTION
Infrared imaging systems generate a visual image based on collected infrared energy. Such a system can provide vision enhancement for the operator of a vehicle by supplying the operator with a head-up display (HUD) of the visual image generated by the infrared imaging system.
Existing HUD systems suffer from several drawbacks. First, the visual image displayed by many systems represents a narrow field-of-view in front of the vehicle. In addition, existing HUD systems produce a negative eyebox, meaning that the entire visual image in the HUD is not visible at any point in the vehicle. These HUD systems may also suffer from large aberrations of the visual image and poor vertical disparity.
SUMMARY OF THE INVENTION
The present invention substantially reduces or eliminates at least some of the disadvantages and problems associated with previous head-up display (HUD) systems. In certain embodiments, the present invention provides a compact, low cost HUD system that displays a wide field-of-view (FOV) and has good eyebox, distortion, and vertical disparity characteristics.
In one embodiment of the present invention, a system that provides a head-up display for an operator of a vehicle includes a collection device that is operable to collect infrared energy and an image source that is coupled to the collection device. The image source is operable to generate a visual image based on the collected infrared energy. The system also includes a lens through which the visual image passes before presentation to the operator of the vehicle and a reflector that is operable to reflect the visual image before presentation to the operator of the vehicle.
In another embodiment, a system that provides a head-up display for an operator of a vehicle includes a collection device that is operable to collect infrared energy and an image source that is coupled to the collection device. The image source is operable to generate a visual image based on the collected infrared energy. The system also includes a beam splitter through which the visual image passes a first time and a second time. The system further includes a first reflector that is operable to reflect the visual image after it passes through the beam splitter the first time and a second reflector that is operable to reflect the visual image after it passes through the beam splitter the second time.
The present invention has several important technical features and advantages. First, placing a lens in the optical path can reduce the distortion and other optical aberrations of the visual image compared to a simple reflective element system, even where the windshield of the vehicle serves as a reflector. Reducing the aberrations improves operator discernability of the visual image. Further, because of the reduced aberrations, the system can display an FOV in front of the vehicle of greater than twelve degrees. Displaying a greater FOV is beneficial to operators negotiating curvy roads and to operators who need to view objects on the side of the road, especially those may enter the path of the vehicle. In addition, the system can provide a positive eyebox, which allows operator head movement while viewing the entire visual image, and a low vertical disparity, which reduces operator eyestrain. Also, the refractive nature of the lens allows for a more compact optical system than a simple reflective element system, allowing the use of a smaller image source, which reduces system cost. Moreover, in particular embodiments, the image source and the lens can fit within the dashboard of the vehicle, a significant ergonomic and aesthetic consideration.
In other embodiments, the HUD system may include an additional reflector. The additional reflector introduces an extra degree of freedom to provide further correction for distortion. Such a system is still compact enough so that the additional reflector can fit within the dashboard with the image source and the lens.
In still other embodiments that use an additional reflector, a beam splitter can replace the lens. Using a beam splitter allows the additional reflector to align substantially symmetric with the optical axis between the reflector and the additional reflector, which improves the optical performance over previous a simple reflective element system. But again, the system uses only a minimum number of optical elements and may be compact enough to fit within the dashboard of the vehicle. Moreover, these embodiments readily allow the image source to use polychromatic light.
Other technical advantages and features will be readily apparent to one skilled in the art from the following figures, description, and claims.
REFERENCES:
patent: 4961625 (1990-10-01), Wood et al.
patent: 5013135 (1991-05-01), Yamamura
patent: 5056890 (1991-10-01), Iino et al
patent: 5289312 (1994-02-01), Hashimoto et al.
patent: 5414439 (1995-05-01), Groves et al.
patent: 5497271 (1996-03-01), Mulvanny et al.
patent: 5657163 (1997-08-01), Wu et al.
patent: 5859714 (1999-01-01), Nakazawa et al.
patent: 5864432 (1999-01-01), Deter
patent: 5867133 (1999-02-01), Toffolo et al.
patent: 26 33 067 A1 (1978-02-01), None
patent: 0 710 866 A1 (1986-05-01), None
patent: 0 312 094 A2 (1989-04-01), None
patent: 0 515 328 A1 (1992-11-01), None
patent: 0 643 315 A1 (1995-03-01), None
patent: 2 693 807 A1 (1992-07-01), None
patent: 2 246 900 (1992-02-01), None
patent: WO 89/03059 (1989-04-01), None
Fresnel Optics Brochure, Fresnel Optics, Inc., Date Unknown, 8 pages.
PCT International Search Report dated Aug. 8, 2000 for PCT/US00/11695 dated Apr. 26, 2000.
Anderson Douglas W.
Mauldin Russell E.
Trotta Patrick A.
Baker & Botts L.L.P.
Epps Georgia
Raytheon Company
Seyrafi Saeed
LandOfFree
Head-up display does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Head-up display, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Head-up display will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2469722