Abstract: An optical system incorporating a compact internal field of view switch configured to switch the field of view of the optical system between a narrow field of view and a wide field of view while maintaining a constant exit aperture size. In one example the optical system includes an active imaging sub-system optically coupled to the exit aperture, and the field of view switch is positioned between the exit aperture and the active imaging sub-system. In one example the field of view switch is configured as a pupil relay having non-unity magnification.

Abstract: An optical system incorporating a compact internal field of view switch configured to switch the field of view of the optical system between a narrow field of view and a wide field of view while maintaining a constant exit aperture size. In one example the optical system includes an active imaging sub-system optically coupled to the exit aperture, and the field of view switch is positioned between the exit aperture and the active imaging sub-system. In one example the field of view switch is configured as a pupil relay having non-unity magnification.

Abstract: A vehicle simulator having a projection system for projecting a generated scene and symbology onto a common viewing screen. Tracking apparatus is provided for providing position and/or angular orientation signals representative of the eye of a person viewing the projected scene and symbology. An image generation system is included for generating the scene and symbology for the projection system, such scene and symbology being generated as a function of the position and/or angular orientation signals provided by the tracking apparatus. Such symbology is representative of symbology produced by a head-up display. The image generation system generates the scene and symbology with characteristics which simulate vignetting and/or occulting effect characteristics of the head-up display.

Abstract: A situation awareness viewing device, typically in the form of a head-mounted display device, includes a polarizing beam splitter made of a cube of a material transparent to light and having an index of refraction greater than 1, and a wire grid polarizer lying within the cube on a cube-diagonal plane extending between two diagonally opposed edges of the cube. The polarizing beam splitter has a first optical axis extending from a first face of the cube toward an opposing second face of the cube and lying at an angle of 45 degrees to the cube-diagonal plane, and a second optical axis extending from a third face of the cube toward an opposing fourth face of the cube and lying at an angle of 45 degrees to the cube-diagonal plane, the second optical axis being perpendicular to the first optical axis.

Abstract: An external pupil lens system (200) with an entrance pupil distance at least three times that of the effective focal length. The lens system is comprised of several conventional lenses and a diffractive optical element (DOE) for secondary chromatic aberration correction. In the illustrative embodiment, the system includes an entrance pupil (50), followed by a lens group (52) containing two refractive elements for primary color correction. Next along the optical axis is lens group (54), which contains two refractive elements for astigmatism and higher order coma correction, followed by lens group (60), which contains one refractive element (62) and one DOE (64) for secondary color correction.

Abstract: A collimating optical device utilizes a reflective beamsplitter in the form of a linear polarizing beamsplitter to achieve a wide field of view. One form of the wide-angle collimating optical device includes, in order from an image source, a first absorptive linear polarizer; a first quarter-wave plate; an optical doublet including a piano-concave singlet, a plano-convex singlet whose convex surface has the same curvature as the curvature of the concave surface, and a first reflective beamsplitter joining the concave surface of the plano-concave singlet to the convex surface of the plano-convex singlet; a second quarter-wave plate; and a second reflective beamsplitter. One of the reflective beamsplitters is a linear polarizing beamsplitter, most preferably a wire grid polarizer.

Abstract: A vehicle simulator having a projection system for projecting a generated scene and symbology onto a common viewing screen. Tracking apparatus is provided for providing position and/or angular orientation signals representative of the eye of a person viewing the projected scene and symbology. An image generation system is included for generating the scene and symbology for the projection system, such scene and symbology being generated as a function of the position and/or angular orientation signals provided by the tracking apparatus. Such symbology is representative of symbology produced by a head-up display. The image generation system generates the scene and symbology with characteristics which simulate vignetting and/or occulting effect characteristics of the head-up display.

Abstract: A collimating optical device utilizes a reflective beamsplitter in the form of a linear polarizing beamsplitter to achieve a wide field of view. One form of the wide-angle collimating optical device includes, in order from an image source, a first absorptive linear polarizer; a first quarter-wave plate; an optical doublet including a plano-concave singlet, a plano-convex singlet whose convex surface has the same curvature as the curvature of the concave surface, and a first reflective beamsplitter joining the concave surface of the plano-concave singlet to the convex surface of the plano-convex singlet; a second quarter-wave plate; and a second reflective beamsplitter. One of the reflective beamsplitters is a linear polarizing beamsplitter, most preferably a wire grid polarizer.

Abstract: An external pupil lens system (200) with an entrance pupil distance at least three times that of the effective focal length. The lens system is comprised of several conventional lenses and a diffractive optical element (DOE) for secondary chromatic aberration correction. In the illustrative embodiment, the system includes an entrance pupil (50), followed by a lens group (52) containing two refractive elements for primary color correction. Next along the optical axis is lens group (54), which contains two refractive elements for astigmatism and higher order coma correction, followed by lens group (60), which contains one refractive element (62) and one DOE (64) for secondary color correction.

Abstract: A display device for a display wavelength range includes an image source, a relay group made of optical elements transparent to the display wavelength range, and a reflective combiner in facing relation to the relay group. The relay group includes a glass optical wedge, a glass lens, and a group of plastic lenses including a diffractive optical element. The group of plastic lenses is positioned between the glass optical wedge and the glass lens. The relay group has the optical wedge having a front face in facing relation to the image source, and a back face; an aspheric lens module having a front face in facing relation to the back face of the optical wedge, and a back face; and an aspheric lens having a front face in facing relation to the back face of the aspheric lens module, a back face, and an optical axis. The aspheric lens module is tilted and decentered with respect to the optical axis of the aspheric lens.

Abstract: A display device for a display wavelength range includes an image source, a relay group made of optical elements transparent to the display wavelength range, and a reflective combiner in facing relation to the relay group. The relay group includes a glass optical wedge, a glass lens, and a group of plastic lenses including a diffractive optical element. The group of plastic lenses is positioned between the glass optical wedge and the glass lens. The relay group has the optical wedge having a front face in facing relation to the image source, and a back face; an aspheric lens module having a front face in facing relation to the back face of the optical wedge, and a back face; and an aspheric lens having a front face in facing relation to the back face of the aspheric lens module, a back face, and an optical axis. The aspheric lens module is tilted and decentered with respect to the optical axis of the aspheric lens.

Abstract: A vehicle simulator having a projection system for projecting a generated scene and symbology onto a common viewing screen. Tracking apparatus is provided for providing position and/or angular orientation signals representative of the eye of a person viewing the projected scene and symbology. An image generation system is included for generating the scene and symbology for the projection system, such scene and symbology being generated as a function of the position and/or angular orientation signals provided by the tracking apparatus. Such symbology is representative of symbology produced by a head-up display. The image generation system generates the scene and symbology with characteristics which simulate vignetting and/or occulting effect characteristics of the head-up display.

Abstract: A situation awareness viewing device, typically in the form of a head-mounted display device, includes a polarizing beam splitter made of a cube of a material transparent to light and having an index of refraction greater than 1, and a wire grid polarizer lying within the cube on a cube-diagonal plane extending between two diagonally opposed edges of the cube. The polarizing beam splitter has a first optical axis extending from a first face of the cube toward an opposing second face of the cube and lying at an angle of 45 degrees to the cube-diagonal plane, and a second optical axis extending from a third face of the cube toward an opposing fourth face of the cube and lying at an angle of 45 degrees to the cube-diagonal plane, the second optical axis being perpendicular to the first optical axis.

Abstract: A wide field-of-view simulator heads-up display provides images to a user along an optical axis. A HUD CRT provides images of a predetermined design wavelength, while rear projection screen CRTs provide out-of-window scenery that does not contain the predetermined design wavelength. A curved holographic combiner is mounted on the optical axis with a reflective hologram on a concave surface covered with a urethane overcoat. The convex surface has an antireflective coating. A tilted beamsplitter cooperates with a folding mirror in a relay optical system for providing a virtual image of the HUD CRT for reflection from the holographic combiner.

Abstract: An optical system (10) has an image source (12), a first optical element (34), a second optical element (50), and an aperture stop (52). The first optical element (34) is positioned close to the image source (12) to generate anamophic field curvature of matching the display screen (16). The radiation is then directed to the second optical element (50) which corrects astigmatism of the radiation passing from the first optical element (34). The aperture stop (52) is provided adjacent to the second optical element (50). The system may be used in an infinite display optical system where the radiation would be directed through projector 14 to a screen (16). A mirror (18) is positioned to reflect the radiation from the screen (16) to provide an image to a viewer.

Abstract: An aviator's helmet-mounted display includes a visor/combiner module (14) which is configured for use with an essentially standard aviator's flight helmet (12). The helmet-mounted display also includes a conformal image source and relay optics (ISRO) module (30) which is removably attachable to the aviator's helmet. This ISRO module (30) projects an image inwardly from outside the visor/combiner module through a transparent window portion (44) thereof and out and inner surface (48) of an angulated transparent viewing portion (18,20) of the visor/combiner module (14). The image is focused at infinity and is partially reflected from the inner surface (48) to an eye (50) of the aviator so that the image is superimposed on the aviator's view of an outside scene viewed through the viewing portion (18,20).

Abstract: An image-projection display (10) includes a combiner (12) which is transparent to allow a view therethrough, and which is also at least partially reflective so that an image projected onto a surface of the combiner is reflected to a viewer. The display apparatus includes off-axis projection factors so that a rectilinear projected image would be perceived by the viewer as being distorted. A projector portion (20) of the display (10) includes an image source (36, 38) and a corrector element (46), as well as means (38, 46) for physically dislocating pixel elements of a rectilinear image so that the image as projected is de-linearized with compensatory distortion causing the image viewed by the viewer to be perceived with restored rectilinearity.

Abstract: A helmet/head mounted display including a display image source and a reflective visor for each eye. The image source includes a fiber optic cover plate with a planar input surface and a curved output surface which has curvature providing the correct curvature. The image source further includes a self-emitting device such as a field electrode display or electroluminescent device, or a polymer dispersed liquid crystal (PDLC) sandwiched between a thin, sharply tapered fiber optic plate and the fiber optic cover plate. For the PDLC image source, back light illumination is introduced through the tapered fiber optic plate, passes through or is scattered by the PDLC and then through the fiber optic face plate to the visor, for reflection to the observer's eye. The fiber optic face plate is constructed with a very low numerical aperture. The fibers of the cover plate are oriented toward the eye as seen in the reflection from the visor to reduce undesirable reflected light.

Abstract: An aviator's helmet-mounted display includes a visor/combiner module (14) which is configured for use with an essentially standard aviator's flight helmet (12). The helmet-mounted display also includes a conformal image source and relay optics (ISRO) module (30) which is removably attachable to the aviator's helmet. This ISRO module (30) projects an image inwardly from outside the visor/combiner module through a transparent window portion (44) thereof and out and inner surface (48) of an angulated transparent viewing portion (18,20) of the visor/combiner module (14). The image is focused at infinity and is partially reflected from the inner surface (48) to an eye (50) of the aviator so that the image is superimposed on the aviator's view of an outside scene viewed through the viewing portion (18,20).

Abstract: An optical arrangement that provides a telecentric helmet mounted display optical system. The optical arrangement comprises an image source including a faceplate wedge attached to a liquid crystal display, such as an active matrix liquid crystal display, for example, that is illuminated with collimated fight. The output image is used as a light source for an off-axis or on-axis reflector used to produce an output image. The faceplate wedge corrects the anamorphic distortion exhibited in the off-axis reflector and directs the light energy into the off-axis entrance pupil of the reflector to maintain high uniformity over the exit pupil without sacrificing brightness. More particularly, the present invention comprises the input light source, and the liquid crystal display that is illuminated with collimated light from the light source. The faceplate wedge is optically coupled to the liquid crystal display, and the reflector is optically coupled to the faceplate wedge for producing an output image.