Head mounted visual display

• US 5,581,271 A
• Filed: 12/05/1994
• Issued: 12/03/1996
• Est. Priority Date: 12/05/1994
• Status: Expired due to Term

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Kraemer, Werner
• Primary Examiner(s): Brier, Jeffery
• Assistant Examiner(s): CHOW, DOON Y
• Application Number:
  US08/349,259
• Time in Patent Office: 729 Days
• Field of Search: 345/8, 345/7, 348/115, 348/56, 340/980, 359/630, 359/201, 359/631, 359/13, 359/14
• US Class Current: 345/8
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/0132 comprising binocular systems
• CPC Class Codes: G02B 2027/0154 with movable elements
• CPC Class Codes: G02B 2027/0159 with mechanical means other than scaning means for positioning the whole image
• CPC Class Codes: G02B 2027/0196 having transparent supporting structure for display mounting, e.g. to a window or a windshield
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/0176 characterised by mechanical features
• CPC Class Codes: G09B 9/307 by helmet-mounted projector or display G09B9/36 takes precedence; optical parts of head-up displays G02B27/01

Abstract

A head mounted visual display for simulation and training that provides to a user a high quality real time video image and a see-through view of the surrounding real world when the video image is off. The display system provides a CRT collimated visual image of high resolution and image quality that has high light transmissivity, anti-luning, and a wide-angle view. The CRT has a fibre optic face plate to reduce CRT mapping distortions.

Claims

1. A head mounted display for receiving images, comprising:

remote electronics control unit;

helmet means for mounting a portable visual image display on a user'"'"'s head;

a first cathode ray tube (CRT) connected to said mounting means, said first CRT having a display screen;

first solid optics block mounted in optical communication with the screen of said first CRT, said first optics block having a first optical light path that includes a concave mirrored reflecting surface and a beam splitting surface such that the image light along said optical first path is transmitted goes from the CRT screen through the beam splitting surface to the mirrored reflecting surface back to the beam splitting surface where it is reflected from the beam splitter directly to the observer'"'"'s eye, said solid optics block including a second optical path that allows direct transmission of light rays from outside said solid optics block directly into the eye of the viewer through said beam splitter;

means connected to said CRT for generating a video image on said first CRT;

video image generating circuit means mounted in said remote electronics control unit;

signal conducting means connected between said remote electronics control unit and said helmet means for communicating video image generated signals between said remote electronics control unit and said first CRT, whereby said helmet mounted display can generate synthetic images for viewing by the observer wearing the helmet means in a first mode and allow see-through viewing by the user in a second mode;

a second cathode ray tube (CRT) connected to said helmet means;

second solid optics block disposed in optical communication with the screen of said second CRT, said second optics block including a beam splitting surface and a reflecting curved surface for collimating light rays, said first CRT and said second CRT and said first solid optics block and said second optics block individually aligned relative to the line of sight of the user'"'"'s eyes independently, whereby the first and second visual displays provide a collimated stereoscopic image; and

a first and second plate for correcting optical distortion including a fibre optic bundle having a plurality of parallel, straight, side-by-side fibre optical members, said plate first end being concave to fit flush against said first and second CRT faces and said first and second plates second ends being convex, said fibre optic plates correcting mapping distortion on said first and second CRT curved surfaces.

2. A head mounted display as in claim 1, wherein:

said first solid optics block and said second solid optics block include optic barriers to prevent luning.

3. A head mounted display as in claim 1, including:

means connected to each of said first and second solid optics blocks and said helmet means for adjustably positioning each of said first and second solid optics blocks relative to the user'"'"'s eyes vertically, laterally for pupil separation, and toward and away from the eye of the user.

4. A head mounted display as in claim 1, including:

video amplifying circuit means mounted and attached to said helmet and electrically connected to each of said CRTs mounted to said helmet and connected by a tethered cable to said electronics control unit, thereby increasing the useful length of said tethered cable without degrading picture quality.

5. A head mounted display as in claim 1, including:

each of said reflecting mirrors providing for an image at infinity relative to the eye point of the user to create a collimated image stereoscopically.