Helmet mounted display configured for simulator use

Claim 2

Head mounted display apparatus providing a variable binocular field of view with variable partial overlap of the left and right monocular fields, said apparatus intended primarily for the investigation of visual display parameters in a flight simulator or other experimental flight environment, comprising: helmet means, adapted to permit attachment of optical components, having an opening in proximity to the eyes of the observer; image source means, being self luminous and adapted to be mounted to said helmet means, for providing images comprising symbols, text or scenic images generated by a computer or from an external sensor such as a TV camera; optic means, adapted to be mounted to said helmet means, for presenting a virtual image of said image source means at a focus of from one meter to infinity in the observer's visual field, said optic means comprising left and right optics modules, each said module including a corresponding one of said image source means and comprising relay optic means and two separate interchangeable optical eyepiece means, each said relay optic means comprising an arrangement of optical components common for usage with each said eyepiece means; and coupling means for releasably engaging said eyepiece means to the corresponding one of said optics modules, said coupling means further comprising means for rotating said eyepiece about an axis of said corresponding optics module, whereby the display system optical axis projecting into the observer's visual field is caused to deviate from the observer's straight forward line of sight, thereby presenting to the observer' visual field a binocular image of variable angular extent comprising partially overlapped left and right images, said binocular image having a central portion comprising a portion of each of said left and right image source means images, said central image portion being presented in common to both eyes, said binocular image also having left and right peripheral image portions being presented respectively to the left and right eyes.

Claim 3

The apparatus of claim 1 , wherein said relay optics means presents an intermediate real image of said image source means along the optical path of said relay optic means, said intermediate image having a magnification of 0.5 to 4.0 which when viewed with said eyepiece means presents said virtual image in the observer's forward visual field.

Claim 4

The apparatus of claim 2, wherein each of said optic modules is disposed on said helmet means in a vertical plane containing the straight forward line of sight, said eyepiece means being rotatable about an axis in said plane orthogonal to the line of sight thereby providing a horizontal field of view of variable angular subtense.

Claim 5

The apparatus of claim 3 , wherein a first type of said eyepiece means is catadioptric, said catadioptric eyepiece comprising partially reflective, partially transmissive optical component means for superimposing a virtual image of said image source means in the observer's view of the external scene, said virtual image occupying a portion of the observer's visual field having a minimum subtense of 10 degrees at the observer's eye, said catadioptric eyepiece having an eye relief of at least 24 millimeters, whereby said catadioptric eyepiece is optimized for viewing the relatively high luminance of said image source means superposed on the observer's view of the external scene.

Claim 6

The apparatus of claim 4 , wherein said catadioptric eyepiece means includes a partially transmissive, partially reflective plane beamsplitter disposed in front of the observer's eye, and a second partially transmissive, partially reflective curved combiner optical component disposed in front of said plane beamsplitter along the observer's line of sight.

Claim 7

The apparatus of claim 5 , wherein a surface of said combiner nearest to the observer's eye is coated with a partially reflective, partially transmissive optical coating having reflectivity in the range of 20 - 60 percent for visible light in the wavelength range of 400 - 700 nanometers.

Claim 8

The apparatus of claim 6 , wherein a surface of said plane beamsplitter farthest from the observer's eye is coated with a partially reflective, partially transmissive optical coating having reflectivity in the range of 20 - 60 percent for visible light in the wavelength range of 400 - 700 nanometers.

Claim 9

The apparatus of claim 7 , wherein a secondary surface of each of said plane beamsplitter and said combiner is coated with an antireflective optical coating for visible light in the wavelength range of 400 - 700 nanometers, whereby said antireflective coating reduces spurious reflections of visible light in the wavelength range of 400 - 700 nanometers.

Claim 10

The apparatus of claim 5 , wherein said combiner comprises a lightweight fused silica glass material.

Claim 11

The apparatus of claim 5 , wherein said plane beamsplitter comprises a lightweight fused silica glass material.

Claim 12

The apparatus of claim 5 , wherein said combiner comprises a polycarbonate or acrylic optical plastic material.

Claim 13

The apparatus of claim 5 , wherein said plane beamsplitter comprises a polycarbonate or acrylic optical plastic material.

Claim 14

The apparatus of claim 4 wherein the effective focal length of said relay optic means optical components together with said catadioptric eyepiece optical components is in the range of 15 - 55 millimeters.

Claim 15

The apparatus of claim 3 , wherein a second type of said eyepiece means is refractive, said refractive eyepiece having a totally reflective plane mirror disposed in front of the observer's eye and at least one lens disposed between the observer's eye and said plane mirror, said plane mirror and said lens disposed to present a virtual image of said image source means in the observer's visual field, said virtual image occupying a portion of the observer's visual field having a minimum subtense of 20 degrees at the observer's eye, said refractive eyepiece having an eye relief of at least 24 millimeters, whereby said refractive eyepiece is optimized for viewing low luminance images provided by said image source means.

Claim 16

The apparatus of claim 14, wherein the effective focal length of said relay optic means optical components together with said refractive eyepiece optical components is in the range of 15 - 55 millimeters.

Claim 17

The apparatus of claim 1, wherein said image source means comprises a miniature cathode ray tube having an active image diameter in the range of 16 - 25 millimeters.

Claim 18

The apparatus of claim 1, wherein said relay optics means optical components are comprised of different optical materials, whereby said different optical materials control chromatic abberrations of visible light.

Claim 19

The apparatus of claim 17, wherein said different optical materials include fused silica glass and F4 glass.

Claim 20

The apparatus of claim 17, wherein said different optical materials include acrylic and polycarbonate.

Claim 21

The apparatus of claim 4 , wherein said image source means includes an output image surface, said relay optic means optical components including a plurality of lenses and a plane folding mirror, said catadioptric eyepiece optical components including at least one field lens, said catadioptric eyepiece optical components together with said output image surface and said relay optic means optical components having the following optical prescription characteristics and inter-component spacing: Component Type Surface No. Radius (mm) Curve Type Thick/Dist (mm) Mat'l Image Source 84 40.000000 CV 62.600000 AIR Lens 85 28.285000 CX 3.000000 F4 Lens 86 20.309000 CV 2.731300 AIR Lens 87 52.397000 CX 5.500000 SIO2 Lens 88 81.200000 CX 22.462960 AIR Lens 89 201.985000 CV 5.500000 SIO2 Lens 90 24.617000 CX 5.342720 AIR Lens 91 1253.000000 CX 4.500000 SIO2 Lens 92 46.488000 CX 1.147060 AIR Lens 93 30.500000 CV 3.000000 F4 Lens 94 98.331000 CX 34.300000 AIR Mirror 95 -- -- 144.000000 AIR Beamsplitter 100 -- -- 33.947919 AIR Combiner 101 137.360000 CV 35.087919 AIR Beamsplitter 100 -- -- 3.000000 ACRYL Beamsplitter 102 -- -- 51.420000 AIR 103 -- -- -- --

Claim 22

The apparatus of claim 14, wherein said image source means includes an output image surface, said relay optic means optical components including a plurality of lenses and a plane folding mirror, said refractive eyepiece optical components including at least one eyepiece lens, said refractive eyepiece optical components together with said output image surface and said relay optic means optical components having the following optical prescription characteristics and inter-component spacing: Component Type Surface No. Radius (mm) Curve Type Thick/Dist (mm) Mat'l Image Source 84 40.000000 CV 61.863200 AIR Lens 85 28.285000 CX 3.000000 F4 Lens 86 20.309000 CV 1.792300 AIR Lens 87 52.397000 CX 6.000000 SIO2 Lens 88 81.200000 CX 21.905600 AIR Lens 89 201.985000 CV 5.500000 SIO2 Lens 90 24.617000 CX 5.209200 AIR Lens 91 1253.000000 CX 4.500000 SIO2 Lens 92 46.488000 CX 1.147060 AIR Lens 93 30.500000 CV 3.000000 F4 Lens 94 98.331000 CX 34.300000 AIR Mirror 95 -- -- 112.929245 AIR Lens 112 58.105000 CX 7.000000 ACRYL Lens 113 89.283000 CX 25.070755 AIR Mirror 114 -- -- 20.500000 AIR Lens 115 -- -- 4.000000 ACRYL Lens 116 83.478000 CX 0.500000 AIR Lens 117 39.515000 CX 4.500000 ACRYL Lens 118 -- -- 25.000000 AIR 103 -- -- -- --

Claim 23

Head mounted display apparatus providing a variable binocular field of view with variable partial overlap of the left and right monocular fields, said apparatus intended primarily for the investigation of visual display parameters in a flight simulator or other experimental flight environment, comprising: helmet means, adapted to permit attachment of optical components, having an opening in proximity to the eyes of the observer; image source means, being self luminous and adapted to be mounted to said helmet means, for providing images comprising symbols, text or graphic images generated by a computer or from an external sensor such as a TV camera; optic means, adapted to be mounted to said helmet means, for presenting a virtual image of said image source means at a focus of from one meter to infinity in the observer's visual field, said optic means comprising left and right relay optics modules, each said module comprising coupling optic means, common relay optic means and optical eyepiece means; viewing objective means, comprising left and right viewing optics modules each being adapted to be mounted to a corresponding one of said relay optics modules, for providing an image of a portion of the external scene disposed beyond said viewing objective means; first coupling means, for releasably engaging said eyepiece means to a corresponding one of said relay optics modules, said coupling means comprising means for rotating said engaged eyepiece means about an axis of said relay optics module, whereby the display system optical axis projecting into the observerls visual field is caused to deviate from the observer's straight forward line of sight, thereby presenting to the observer a binocular image of variable angular extent comprising partially overlapped left and right images; and second coupling means, for releasably engaging each said viewing objective means to a corresponding one of said optic means, said coupling means comprising means for rotating said engaged viewing objective means about an axis parallel to said eyepiece means axis of rotation, whereby said viewing objective means rotation presents left and right images of the external scene in the observer's visual field, said left and right external scene images comprising both a common image portion in the view of both of said viewing objective means and separate left and right peripheral image portions being in the view respectively of said left and right viewing objective means, the observer further rotating said corresponding eyepiece means by a corresponding amount in response to said viewing objective means rotation, said eyepiece means rotation and said viewing objective means rotation varying the total field of view and correspondingly the degree of binocular overlap of said external scene images being presented to the observer's eyes.

Claim 24

Head mounted display apparatus providing a variable binocular field of view with variable partial overlap of the left and right monocular fields, said apparatus intended primarily for the investigation of visual display parameters in a flight simulator or other experimental flight environment, comprising: helmet means, adapted to permit attachment of optical components, having an opening in proximity to the eyes of the observer; image source means, being self luminous and adapted to be mounted to said helmet means, for providing images comprising symbols, text or graphic images generated by a computer or from an external sensor such as a TV camera; optic means, adapted to be mounted to said helmet means, for presenting a virtual image of said image source means at a focus of from one meter to infinity in the observer's visual field, said optic means comprising left and right relay optics modules, each said module comprising coupling optic means, common relay optic means and optical eyepiece means; viewing objective means, comprising left and right viewing optics modules each being adapted to be mounted to a corresponding one of said relay optics modules, for providing an image of a portion of the external scene disposed beyond said viewing objective means; first coupling means, for releasably engaging said eyepiece means to a corresponding one of said relay optics modules, said coupling means comprising means for rotating said engaged eyepiece means about an axis of said relay optics module, whereby the display system optical axis projecting into the observerls visual field is caused to deviate from the observer's straight forward line of sight, thereby presenting to the observer a binocular image of variable angular extent comprising partially overlapped left and right images; and second coupling means, for releasably engaging each said viewing objective means to a corresponding one of said optic means, said coupling means comprising means for rotating said engaged viewing objective means about an axis parallel to said eyepiece means axis of rotation, whereby said viewing objective means rotation presents left and right images of the external scene in the observer's visual field, said left and right external scene images comprising both a common image portion in the view of both of said viewing objective means and separate left and right peripheral image portions being in the view respectively of said left and right viewing objective means, the observer further rotating said corresponding eyepiece means by a corresponding amount in response to said viewing objective means rotation, said eyepiece means rotation and said viewing objective means rotation varying the total field of view and correspondingly the degree of binocular overlap of said external scene images being presented to the observer's eyes.

Claim 25

The apparatus of claim 22, wherein said viewing objective means comprises: objective lens means, for providing an image of a portion of an external scene disposed beyond said viewing objective lens means; optical inverter means, having an output image surface, for rotating said external scene image by 180 degrees and providing said rotated image on said output image surface; optical reflecting means, for directing said rotated image towards a corresponding one of said common relay optic means; and optical beamsplitter means, disposed in the optical path of said common relay optic means, for simultaneously reflecting the light rays indicative of said rotated image into the optical path of said common relay optic means and transmitting the light rays from said image source means along the optical path of said common relay optic means.

Claim 26

The apparatus of claim 23, wherein said optical reflecting means comprises a mirror.

Claim 27

The apparatus of claim 23, wherein said optical reflecting means comprises a prism.

Claim 28

The apparatus of claim 23, wherein said optical inverter means comprises a fiber optic inverter.

Claim 29

The apparatus of claim 23, wherein said common relay optics means presents an intermediate real image of said image source means along the optical path of said common relay optic means, said intermediate image having a magnification of 0.5 to 4.0 which when viewed with said eyepiece means presents said virtual image in the observer's forward visual field.

Claim 30

The apparatus of claim 27, wherein each said relay optics module is disposed on said helmet means in a vertical plane containing the straight forward line of sight, said eyepiece means being rotatable about an axis in said plane orthogonal to the line of sight thereby providing a horizontal field of view of variable angular subtense.

Claim 31

The apparatus of claim 28, wherein said eyepiece means is refractive, said refractive eyepiece having a totally reflective plane mirror disposed in front of the observer's eye and having at least one lens disposed between the observer's eye and said plane mirror, said plane mirror and said lens disposed to present a virtual image of said intermediate real image in the observer's visual field, said virtual image occupying a portion of the observer's visual field having a minimum subtense of 20 degrees at the observer's eye, said refractive eyepiece having an eye relief of at least 24 millimeters, whereby said refractive eyepiece is optimized for viewing the relatively low luminance of said external scene image superposed with said image source means image.

Claim 32

The apparatus of claim 29, wherein the effective focal length of said relay optic means optical components together with said refractive eyepiece optical components is in the range of 15 - 55 millimeters.

Claim 33

The apparatus of claim 22, wherein said image source means comprises a miniature cathode ray tube having an active image diameter in the range of 16 - 25 millimeters.

Claim 34

The apparatus of claim 22, wherein said relay optics means optical components are comprised of different optical materials, whereby said different optical materials control chromatic abberrations of visible light.

Claim 35

The apparatus of claim 32, wherein said different optical materials include fused silica glass and F4 glass.

Claim 36

The apparatus of claim 32, wherein said different optical materials include acrylic and polycarbonate.

Claim 37

The apparatus of claim 34, wherein said image source means includes an output image surface, said common relay optic means optical components including a plurality of lenses and a plane folding mirror, said refractive eyepiece optical components including at least one eyepiece lens, said refractive eyepiece optical components together with said output image surface, said viewing objective means and said common relay optic means optical components having the following optical prescription characteristics and inter-component spacing: Component Type Surface No. Radius (mm) Curve Type Thick/Dist (mm) Mat'l Image Surface 256 30.619700 CV 4.000000 AIR Prism 302 -- -- 12.000000 ACRYL Prism 303 -- -- 12.000000 ACRYL Prism 304 -- -- 26.650000 AIR Beamsplitter 301 -- -- 15.150000 AIR Lens 85 28.285000 CX 3.000000 F4 Image Source 84 40.000000 CV 61.863200 AIR Beamsplitter 300 -- -- 1.000000 SIO2 Beamsplitter 301 -- -- 15.150000 AIR Lens 85 28.285000 CX 3.000000 F4 Lens 86 20.309000 CV 1.792300 AIR Lens 87 52.397000 CX 6.000000 SIO2 Lens 88 81.200000 CX 21.905600 AIR Lens 89 201.985000 CV 5.500000 SIO2 Lens 90 24.617000 CX 5.209200 AIR Lens 91 1253.000000 CX 4.500000 SIO2 Lens 92 46.488000 CX 1.147060 AIR Lens 93 30.500000 CV 3.000000 F4 Lens 94 98.331000 CX 34.300000 AIR Mirror 95 -- -- 112.929245 AIR Lens 112 58.105000 CX 7.000000 ACRYL Lens 113 89.283000 CX 25.070755 AIR Mirror 114 -- -- 20.500000 AIR Lens 115 -- -- 4.000000 ACRYL Lens 116 83.478000 CX 0.500000 AIR Lens 117 39.515000 CX 4.500000 ACRYL Lens 118 -- -- 25.000000 AIR 103 -- -- -- --