Head mounted displays

• US 3,923,370 A
• Filed: 10/15/1974
• Issued: 12/02/1975
• Est. Priority Date: 10/15/1974
• Status: Expired due to Term

• Current Assignee: Richard N. Mostrom
• Original Assignee: Richard N. Mostrom
• Inventors: Mostrom, Richard N.
• Primary Examiner(s): Mullins, James B.
• Application Number:
  US05/514,512
• Time in Patent Office: 413 Days
• Field of Search: 350/55,145,146,294,298,301
• US Class Current: 359/630
• CPC Class Codes: G02B 2027/0123 comprising devices increasing the field of view
• CPC Class Codes: G02B 2027/0143 the two eyes not being equipped with identical nor symmetrical optical devices
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features

Abstract

A head mounted display comprising a helmet having a visor which is, at least in part, a paraboloid, two portions of which are treated so as to be at least partially reflective. The visor is attached to a helmet adapted to be worn by a person. Also mounted on the helmet is projection apparatus and a reflective surface which is located substantially in a plane perpendicular to the axis of revolution of the paraboloid and passing through the focal point thereof. The projection apparatus transmits light from a desired object to the first of the reflective portions of the visor where that light is reflected to the reflective surface on the helmet and thence reflected to the second of the reflective portions on the visor where a final reflection of the rays produces the desired image within the field of view of the person wearing the helmet. The invention is characterized by placing the optical elements of the system non-symmetrically about the axis of revolution of the paraboloid, such that the reflective surface on the helmet is substantially out of the field of view of the person.

Claims

1. In a display apparatus for use with headgear having a visor with at least two partially reflective areas thereon which are part of a paraboloid having an axis of rotation;

means for producing an image;

optical means for projecting light from said means to a first of the two areas on the visor for reflection therefrom to a reflecting surface on the headgear and for reflection therefrom to the second of the two areas on the visor so as to form the desired image for viewing by the wearer, the improvement comprising mounting the optical means and the reflecting areas asymmetrically about the axis such that a line drawn from the eye of the wearer to the center of the aperture of the second of the two areas is at a raised angle with respect to a line drawn from the eye of the wearer parallel to the axis.

2. Apparatus according to claim 1 wherein the raised angle is between 8* and 14*.

3. Apparatus of the class described comprising in combination:

headgear adapted to be worn by a person;

a visor on said headgear having at least two portions on the surface thereof which portions are part of a paraboloid having an axis of rotation, the two portions being coated so as to reflect at least part of the light incident thereon, the two portions lying on the surface of the visor and generally on opposite sides of the axis of rotation;

a reflecting surface on said headgear;

image producing means;

projection means for transmitting light from said image producing means to a first of the two portions where it is reflected to said reflecting surface and from said reflecting surface to the second of the two portions to form the desired image for viewing by the person;

the two portions and the reflecting surface being characterized by being non-symmetrical about the axis and with the reflecting surface being substantially above the field of view of the person.

4. A headgear mounted display comprising in combination:

headgear adapted to be worn by a person;

means for projecting an image;

a visor connected to said headgear;

first and second areas on said visor being portions of a paraboloid having an axis and a focal point, and being at least partly reflective and positioned asymmetrically about the axis;

a reflective surface on said headgear lying substantially in a plane perpendicular to the axis and passing through the focal point, the aperture of said reflective surface being asymmetrical about the axis, said means projecting light to the first of said areas for reflection to said reflective surface and thereafter to the second of the areas so as to form the desired image for viewing by the person.

5. Apparatus according to claim 4 wherein said means is mounted on said headgear.

6. Apparatus according to claim 4, wherein the center of the aperture on thE first of the areas is above and to one side of the axis, the center of the aperture on the second of the areas is below and to the other side of the axis and the center of the aperture on the reflective surface is above the axis.

7. Apparatus according to claim 6, wherein the aperture on the second of the areas is centered approximately 10* above a line from the eye of the person parallel with the axis.

8. Apparatus of the class described comprising, in combination:

a helmet adapted to be worn by a person;

a substantially transparent visor mounted on said helmet, said visor being, in part, a paraboloid having an axis of revolution, a focal point, and having first and second reflective portions located generally on opposite sides of the axis of revolution and in the paraboloid part;

a reflective surface mounted on said helmet, generally in a plane including the focal point and perpendicular to the axis of revolution but having an aperture centered at a point above the focal point;

projection means mounted on said helmet for directing light to the first of the reflective portions on said visor where the light is reflected to the reflective surface on said helmet where the light is again reflected to the second of the reflective portions on said visor and an image is formed substantially at infinity for viewing by the person;

the second of the reflective portions being placed such that a line from the eye of the person to the center of the aperture of the second of the reflective portions is at a substantial angle to a line extending from the eye of the person parallel with the axis of revolution.