Abstract: A pair of optical prisms arranged in a complementary relationship provides for anamorphic magnification and cooperates with a refractive or diffractive cylindrical lens element, the later of which generates an aberration that at least partially compensates an aberration generated by the pair of optical prisms. The refractive or diffractive cylindrical lens element is rotated out of normal with respect to the optic axis of the system so as to provide for reflecting stray light away from the optic axis.

Abstract: A pair of optical prisms arranged in a complementary relationship provides for anamorphic magnification and cooperates with a refractive or diffractive cylindrical lens element, the later of which generates an aberration that at least partially compensates an aberration generated by the pair of optical prisms. The refractive or diffractive cylindrical lens element is rotated out of normal with respect to the optic axis of the system so as to provide for reflecting stray light away from the optic axis.

Abstract: A color image is generated as a composite of images from different image modulators, each modulating a different color, and chromatic aberration of at least one optical element in the associated optical system is compensated by scaling or shifting images from different image modulators differently.

Abstract: A pair of prisms arranged in a complementary relationship provides for anamorphic magnification and cooperates with a curved refractive element, the later of which generates an aberration that at least partially compensates an aberration generated by the pair of prisms. Examples of the curved refractive element include, but are not limited to, a cylindrical lens, a curved substrate of optical material, a pair of counter-rotatable cylindrical lenses, a fluid-filled cylindrical lens with variable power incorporating a substrate that is deformed by a clamp mechanism over a fulcrum or curved surface, and at least one curved surface of fixed or variable curvature of the prisms, the later of which may be fluid-filled. In one embodiment, a color image is generated as a composite of images from different image modulators, each modulating a different color, and chromatic aberration is compensated by electronically scaling or shifting images from different image modulators differently.

Abstract: A pair of prisms arranged in a complementary relationship provides for anamorphic magnification and cooperates with a curved refractive element, the later of which generates an aberration that at least partially compensates an aberration generated by the pair of prisms. Examples of the curved refractive element include, but are not limited to, a cylindrical lens, a curved substrate of optical material, a pair of counter-rotatable cylindrical lenses, a fluid-filled cylindrical lens with variable power incorporating a substrate that is deformed by a clamp mechanism over a fulcrum or curved surface, and at least one curved surface of fixed or variable curvature of the prisms, the later of which may be fluid-filled. In one embodiment, a color image is generated as a composite of images from different image modulators, each modulating a different color, and chromatic aberration is compensated by electronically scaling or shifting images from different image modulators differently.

Abstract: Temporally interlaced first and second sequential pluralities of image frames are displayed and alternately directed along respected first and second optical paths to distinct viewing locations, for example the left and right eyes of a viewer, wherein the image frames of one of the sequential pluralities represent mirror images of the object being imaged. In one aspect, both sets of sequential pluralities of image frames are simultaneously distributed to both optical paths and first and second shutters are controlled in synchronism with the image display so as to display the respective sequential pluralities of image frames only at the corresponding viewing locations. In another aspect, respective first and second sequential pluralities of image frames are switched between the first and second optical paths by synchronously switching the polarization state of the image display and by a polarizing beam splitter.

Abstract: An optical modulator (19) utilizes a variable beam splitter arrangement having two separate plano-periodic cylindrical lens arrays (20 and 22) arranged as a sandwiched air-spaced assembly with the plano surfaces facing outwardly from the assembly. The assembly further includes a means (26) for controllably translating or moving one of the lenses relative to the other. The periodic array is formed as alternating concave and convex cylindrical structures. In a nominal setting, the optical axes of the concave structures of one of the lens arrays are aligned with the optical axes of the convex structures of the other so that the assembly acts as an afocal window having little impact when placed in an optical system. To adjust the beam splitting properties, one lens array is slightly translated with respect to the other to cause controlled misalignment of the two lens array surfaces.

Abstract: A portable, electronic imaging system (100) includes a compact housing (102) extending across and beyond the eyes of the user, a wide field of view binocular viewfinder imaging subsystem (104) operating on an image produced by an electronic display subsystem (104) located within the housing, speakers (106) integrally mounted with the housing, an internal, interactive electronic control subsystem (108) to control the functions of the system, and an external input/output interface (110) to facilitate connection with a plurality of optional external devices and/or modules. The housing may further provide for modular mounting and removal of a plurality of optional system modules such as the electronic camera (120), a video tape record and playback device and battery (122), the electronic display (118), a night vision camera, a television tuner, a video game electronic system, a head orientation and position tracking device, or a means for mounting the system on the user's head.

Abstract: A portable, electronic imaging system (100) includes a compact housing (102) extending across and beyond the eyes of the user, a wide field of view binocular viewfinder imaging subsystem (104) operating on an image produced by a pop-up electronic display subsystem (124) when positioned within the housing in a first configuration, speakers (106) integrally mounted with the housing, an internal, interactive electronic control subsystem (108) to control the functions of the system, and an external input/output interface (110) to facilitate connection with a plurality of optional external devices. The pop-up display allows positioning of the display in a second configuration so that the image produced thereon can be viewed externally from the housing (102).

Abstract: A retroreflecting polarizer comprises a pair of first and second substrates, each essentially like the other, each having a planar first surface and a structured second surface, whereby the structured second surface comprises a linear array of isosceles prisms with faces formed at an angle of approximately tan.sup.-1 (1/n) with respect to the planar first surface. The respective structured second surfaces of the first and second substrates are mated with one another through one or more of substantially uniformly thick layers, all of the same optical material, that are parallel to the structured surfaces. The structured surfaces and layers are separated from one another by associated air gaps. The interfaces formed within the retroreflecting polarizer satisfy Brewster's condition for a light beam normally incident upon the retroreflecting polarizer which is split into a .sigma.-polarized retroreflected light beam and a substantially .pi.-polarized transmitted light beam.

Abstract: A portable, electronic imaging system (100) includes a compact housing (102) extending across and beyond the eyes of the user, a wide field of view binocular viewfinder imaging subsystem (104) operating on an image produced by an electronic display subsystem (104) located within the housing, speakers (106) integrally mounted with the housing, an internal, interactive electronic control subsystem (108) to control the functions of the system, and an external input/output interface (110) to facilitate connection with a plurality of optional external devices and/or modules. The housing may further provide for modular mounting and removal of a plurality of optional system modules such as the electronic camera (120), a video tape record and playback device and battery (122), the electronic display (118), a night vision camera, a television tuner, a video game electronic system, a head orientation and position tracking device, or a means for mounting the system on the user's head.

Abstract: An optical modulator (19) utilizes a variable beam splitter arrangement having two separate plano-periodic cylindrical lens arrays (20 and 22) arranged as a sandwiched air-spaced assembly with the plano surfaces facing outwardly from the assembly. The assembly further includes a means (26) for controllably translating or moving one of the lenses relative to the other. The periodic array is formed as alternating concave and convex cylindrical structures. In a nominal setting, the optical axes of the concave structures of one of the lens arrays are aligned with the optical axes of the convex structures of the other so that the assembly acts as an afocal window having little impact when placed in an optical system. To adjust the beam splitting properties, one lens array is slightly translated with respect to the other to cause controlled misalignment of the two lens array surfaces. The present invention is particularly suited for tuning the point spread function of an electronic imaging system.

Abstract: A wide FOV imaging system (10) includes an objective lens (14), a convergent reflective element (18) positioned proximate an intermediate image (16) formed by the objective lens, and a re-imaging lens (20) for re-imaging the intermediate image. The present invention significantly improves image fidelity while minimizing optical components by utilizing a convergent reflective element proximate the intermediate image to reverse the propagation of aberrations produced by the objective lens (14) to, as a result, significantly cancel or reduce the aberrations contributed by the re-imaging lens.

Abstract: An optical subsystem (14) for use in an electronic imaging system (10) utilizes a spatial filter (20) having a concentric optical path profile for removing unwanted structures in the optically formed image. In a first embodiment, the filter (20) includes an axisymmetric conical surface (24) formed on an optical substrate (22) to provide a light path modifying profile designed to achieve a desired circular point spread function in an image plane (16). Other embodiments include an elliptical/conical profile, and an axisymmetric, concentric ring profile. The filter profile may be single-point diamond turned into a flat filter substrate, or can be combined/integrated with the profile of an existing optical system element, such as lens (18). The present invention further provides a method for removing unwanted artificial image structures by generating an imaging system point spread function which is a hollow, closed path.

Abstract: A wide FOV binocular imaging system utilizes an imaging structure (14) to produce an intermediate image (16), and a field lens (18) and beam splitting surface (20) located proximate the intermediate image to concentrate, split, and direct the light from the intermediate image into an eye lens (22) at two viewing zones exit pupils (22(a), 22(b)). The present invention produces a wide FOV and comfortable exit pupil while employing a single entrance pupil.

Abstract: An imaging system (10) for a Head-Mounted Display (HMD) comprises a projection screen (22) integrally formed with a headgear structure of the HMD. An image source is projected onto the projection screen (22) as an intermediate image. An optical sub-system (24), such as a lens, re-images the intermediate image to form a virtual image as viewed by a user's eye (26). The present invention provides improved imaging while reducing the weight and manufacturing cost of the HMD. In accordance with another aspect of the present invention, an optical spatial filter (28) is utilized in an HMD imaging system to remove unwanted image artifacts, and increase the depth of focus of an intermediate projected image.

Abstract: A nonabsorbing polarizing optical beam splitter is described comprising a transparent substrate supporting a layer of adjacent flat beam-splitting channels. Each of the beam-splitting channels abuts respective adjacent channels at a 90.degree. angle to form a contiguous alternating orientation relative to the substrate. Each of the beam-splitting channels reflects a first polarization component of a light beam oriented parallel to the beam-splitting channels, and allows a second remaining polarization component of the light beam to pass through the plurality of beam-splitting channels relatively unperturbed.

Abstract: An optical filter 10 for filtering spatial frequencies from an output of an optical imaging system comprises a substantially transparent, or reflective, optical element 12 having a plurality of light refracting, or reflecting, segments 18 arranged on a surface thereof. Each of the plurality of segments 18 is provided with a predetermined angle of refraction, or reflection, distinct from adjacently located segments 18, wherein the different angles of refraction, or reflection, and the arrangement of the segments 18 on the optical element 12, are determined based on a desired spatial frequency transfer function for the filter 10. The optical spatial filter 10 reduces errors in optically formed images by accurately confining a broadened Point Spread Function (PSF) to a desired spot size.

Abstract: An optical, phase-only spatial filter for filtering spatial frequencies from the output of an optical imaging system is described which comprises an optical element comprised of a pattern of transparent (or reflective, in the case of a mirror) segments, each of which produces an optical path length generally different from that of other segments, and the design of which and the pattern they form dictated by the desired system optical transfer function.

Abstract: A wide FOV imaging system (10) includes an objective lens (14), a convergent reflective element (18) positioned proximate an intermediate image (16) formed by the objective lens, and a re-imaging lens (20) for re-imaging the intermediate image. The present invention significantly improves image fidelity while minimizing optical components by utilizing a convergent reflective element proximate the intermediate image to reverse the propagation of aberrations produced by the objective lens (14) to, as a result, significantly cancel or reduce the aberrations contributed by the re-imaging lens.