Aperture for night vision goggles for use in aircraft simulator or other simulators
An aperture mechanism for night vision goggles (NVG) has a first end, a second end, a lens engaging portion, and a cone portion. A lens engaging portion has a recession allowing attachment of the aperture mechanism to a light admitting end of the NVG. A cone portion is opposite the lens engaging portion. Together the lens engaging portion and the cone portion form an aperture. The aperture mechanism increases the depth of field of the NVG for applications involving small object-to-goggle distances, such as in simulators or simulator environments. In a simulator system, the aperture mechanism can be attached to NVG such that at least a portion of light from a display screen is blocked. The light output of the display screen can be increased such that the depth of field remains higher but the image produced does not become darker.
1. A method of using night vision goggles (NVG) in a simulator system with at least one display screen, comprising the steps of:
attaching to said NVG an aperture mechanism having a cone portion, wherein said aperture mechanism has a first end, a second end, an engaging portion extending from said first end toward said second end, and said cone portion extending from said engaging portion to said second end and wherein said cone portion has an aperture therethrough such that said aperture is aligned and in direct contact with a lens of said NVG;
aiming said NVG in a direction of a portion of said at least one display screen;
radiating an amount of light from said at least one display screen in a direction of said lens of said NVG;
blocking at least a portion of said amount of light radiated in said radiating step with said aperture mechanism; and
producing a focused image with said NVG;
wherein said focused image is produced for multiple different portions of said at least one display screen having different object-to-goggle distances with said NVG, said multiple different portions of said at least one display screen being within a depth of field which is greater than an initial depth of field of said NVG without said attached aperture mechanism, said depth of field being a range of object-to-goggle distances, an upper bound and a lower bound of which are less than twenty feet.
2. The method of claim 1 , further comprising the step of
radiating an additional amount of light from said at least one display screen in a direction of said lens of said NVG,
wherein said blocking step comprises blocking at least a portion of said additional amount of light radiated in second said radiating step with said aperture.
3. The method of claim 2 , wherein said blocking step prevents overexposure of said NVG.
4. The method of claim 1 , wherein said depth of field is equal to or less than 2 feet.
5. The method of claim 1 , wherein said focused image is produced only from light passed through said aperture of said aperture mechanism directly into said lens of said NVG.
6. The method of claim 1 , wherein said attaching is by a friction fit between an inner surface of said aperture mechanism and an outer surface of said NVG.
7. The method of claim 1 , wherein said attaching step attaches said aperture mechanism externally to a light admitting end of said NVG.
8. The method of claim 7 , wherein said attaching step comprises:
contacting the cone portion of said aperture mechanism with said lens; and
engaging said engaging portion with a light admitting end of said NVG, wherein said cone portion forms said aperture continuous from a contact point with said lens to said second end after completion of said attaching step.
9. The method of claim 1 , wherein said attaching step comprises
aligning said aperture with said lens; and
contacting a cone portion of said aperture mechanism with said lens.
10. The method of claim 1 , wherein said blocking step is performed so that passage of light through said aperture is permitted only through a center inner portion of said lens.
11. A method of using night vision goggles (NVG) in a simulator system with at least one display screen radiating light in a direction of a lens of said NVG, comprising the steps of:
attaching to said NVG an aperture mechanism having a cone portion, wherein said aperture mechanism has a first end, a second end, an engaging portion extending from said first end toward said second end, and said cone portion extending from said engaging portion to said second end and wherein said cone portion has an aperture therethrough such that said aperture is aligned and in direct contact with said lens of said NVG and permits passage of light through only an inner portion of said lens;
positioning said NVG at a first object-to-goggle distance with respect to a viewing object of said at least one display screen;
producing a focused image of said viewing object with said NVG at said first object-to-goggle distance after said NVG has said aperture mechanism attached thereto; and
moving said NVG toward or away from said at least one display screen so that said NVG are positioned at a second object-to-goggle distance that is greater or less than said first object-to-goggle distance, wherein said image produced with said NVG stays in focus throughout said moving step without adjustment of settings of said NVG, wherein said first and second object-to-goggle distances are each under 20 feet.
12. The method of claim 11 , wherein said moving step moves said NVG either toward or away from said at least one display screen by at least two feet.
13. The method of claim 11 , wherein said step of attaching to said NVG said aperture mechanism doubles a distance over which said NVG stays in focus throughout said moving step without adjustment of settings of said NVG.