Abstract: A zoom relay system includes an optical element for receiving light from an object. The zoom relay system is adapted to generate an image of the object on an image plane. The system includes a single varifocal lens group positioned along an optical axis. The varifocal lens group includes at least one lens for providing magnification and a varifocal freeform lens including two lens plates. The lens plates are configured to be disposed along a dimension transverse to the optical axis, such that, when the varifocal lens group is moved along the optical axis to adjust the magnification, the lens plates of the varifocal freeform lens are displaced in the transverse dimension relative to each other to provide compensation, such that, when the magnification is changed, a distance between the object and the image plane remains constant.

Abstract: An optical system with adjustable eye relief includes a relay lens assembly. The relay lens assembly is defined by a collimating lens and a focusing lens. The optical system includes an aperture stop. The aperture stop is configured to shift axially along an optical axis between the collimating lens and the focusing lens. The optical system also includes an afocal lens assembly. The afocal lens assembly is defined by the focusing lens and an eyepiece. Additionally, an axial shift of the aperture stop along the optical axis between the collimating lens and the focusing lens changes an eye relief of the eyepiece based on a transverse magnification of the afocal lens assembly.

Abstract: A locking rail mount including a body mounted adjacent to a mounting rail and a clamp screw extending through a channel defined by the body and across the mounting rail. The clamp screw includes a screw head having a surface facing toward the mounting rail with locking elements having a surface relief geometry. At least one compression spring is positioned between the body and a rail clamp that pushes the rail clamp toward the surface of the screw head. The surface of the rail clamp includes locking elements having the surface relief geometry that are complementarily arranged with respect to the locking elements of the screw head. When the clamp screw is tightened, the locking elements of the rail clamp and screw head are aligned to lock the rail clamp and clamp screw together to prevent unintended rotation of the clamp screw.

Abstract: A rail mounting assembly for mounting an accessory to a rail of a firearm includes a base portion arranged to support the accessory. The assembly includes a lock nut receiving recess on a first side portion and a moveable clamp on a second side portion where the side portions cooperate to grip the rail. A crossbar extends between the side portions such that the crossbar is movable relative to the moveable clamp. A lock nut is threadably engageable to an end of the crossbar proximate to the first side portion and a lock plate is positioned within the lock nut receiving recess between the lock nut and a spring disk when the lock nut is threadably engaged with the crossbar. The lock nut receiving recess is shaped to prevent rotation of the lock plate while allowing rotation of the lock nut.

Abstract: A digital booster for an optical system includes an image acquisition unit. The image acquisition unit is configured to acquire an image frame from a non-magnified optic. The image frame includes an aiming reticle imposed by the non-magnified optic. The digital booster includes a display and a processor. The processor is configured to locate the aiming reticle on the image frame, select a sub-frame of the image frame with an aspect ratio that is centered on the aiming reticle of the image frame, perform image inversion and rescaling of the sub-frame, and transmit the sub-frame to the display.

Abstract: In some embodiments, a method includes: selecting dimensions of a slot to be provided in a device feature, the dimensions selected to accommodate one or more tools while resulting in tangential contact between the slot and the one or more tools when the one or more tools are inserted into the slot and used to manipulate the device feature; and forming the slot in a surface of the device feature according to the selected dimensions.

Abstract: An optical system with adjustable eye relief includes a relay lens assembly. The relay lens assembly is defined by a collimating lens and a focusing lens. The optical system includes an aperture stop. The aperture stop is configured to shift axially along an optical axis between the collimating lens and the focusing lens. The optical system also includes an afocal lens assembly. The afocal lens assembly is defined by the focusing lens and an eyepiece. Additionally, an axial shift of the aperture stop along the optical axis between the collimating lens and the focusing lens changes an eye relief of the eyepiece based on a transverse magnification of the afocal lens assembly.

Abstract: A digital booster for an optical system includes an image acquisition unit. The image acquisition unit is configured to acquire an image frame from a non-magnified optic. The image frame includes an aiming reticle imposed by the non-magnified optic. The digital booster includes a display and a processor. The processor is configured to locate the aiming reticle on the image frame, select a sub-frame of the image frame with an aspect ratio that is centered on the aiming reticle of the image frame, perform image inversion and rescaling of the sub-frame, and transmit the sub-frame to the display.

Abstract: A variable magnification optical system with boresight error correction includes a focusing lens to receive light along an optical axis of the variable magnification optical system, with the focusing lens configured to create an image of a target at a focal plane. The system includes a magnification changer disposed along the optical axis, with the magnification changer including an optomechanical drive system to adjust an optical magnification setting of one or more zoom lenses. The system also includes a light source configured to emit a pilot beam into the magnification changer. The system includes a position sensitive photodetector configured to receive the pilot beam exiting the magnification changer. The system further includes a microdisplay optically conjugate to the focal plane, with the microdisplay configured to impose an image of an electronic reticle on the focal plane based on the position of the pilot beam relative to the position sensitive photodetector.

Abstract: A zoom relay system includes an optical element for receiving light from an object. The zoom relay system is adapted to generate an image of the object on an image plane. The system includes a single varifocal lens group positioned along an optical axis. The varifocal lens group includes at least one lens for providing magnification and a varifocal freeform lens including two lens plates. The lens plates are configured to be disposed along a dimension transverse to the optical axis, such that, when the varifocal lens group is moved along the optical axis to adjust the magnification, the lens plates of the varifocal freeform lens are displaced in the transverse dimension relative to each other to provide compensation, such that, when the magnification is changed, a distance between the object and the image plane remains constant.

Abstract: An auto-center barrel cam for small optical systems including an outer barrel having a first channel extending longitudinally where the first channel is tapered from an inner surface to an outer surface of the outer barrel at a first angle and an inner barrel within the outer barrel. The inner barrel including a second channel extending longitudinally along the inner barrel where the second channel is tapered from an inner surface to an outer surface of the inner barrel at a second angle. A cam follower includes a flexure part having a first section with a first surface and a second section with a second surface. A spring section pulls the first section and the second section toward each other. The flexure part is arranged to maintain the cam follower within a center of the first and second channels as the inner barrel moves in relation to the outer barrel.

Abstract: A locking rail mount including a body mounted adjacent to a mounting rail and a clamp screw extending through a channel defined by the body and across the mounting rail. The clamp screw includes a screw head having a surface facing toward the mounting rail with locking elements having a surface relief geometry. At least one compression spring is positioned between the body and a rail clamp that pushes the rail clamp toward the surface of the screw head. The surface of the rail clamp includes locking elements having the surface relief geometry that are complementarily arranged with respect to the locking elements of the screw head. When the clamp screw is tightened, the locking elements of the rail clamp and screw head are aligned to lock the rail clamp and clamp screw together to prevent unintended rotation of the clamp screw.

Abstract: A rail mounting assembly for mounting an accessory to a rail of a firearm includes a base portion arranged to support the accessory. The assembly includes a lock nut receiving recess on a first side portion and a moveable clamp on a second side portion where the side portions cooperate to grip the rail. A crossbar extends between the side portions such that the crossbar is movable relative to the moveable clamp. A lock nut is threadably engageable to an end of the crossbar proximate to the first side portion and a lock plate is positioned within the lock nut receiving recess between the lock nut and a spring disk when the lock nut is threadably engaged with the crossbar. The lock nut receiving recess is shaped to prevent rotation of the lock plate while allowing rotation of the lock nut.

Abstract: A direct view optical sighting system. In certain examples the system includes an eyepiece, an objective that directs scene light to the eyepiece, a laser rangefinder, and a laser rangefinder coupling prism that directs a laser transmit beam from the laser rangefinder to the objective and a laser return beam from the objective to the laser rangefinder. Examples of the system further include a display assembly including a reticle prism and a display coupling prism, the reticle prism being positioned along the optical path between the laser rangefinder coupling prism and the display coupling prism and having a hard reticle formed on a surface thereof. The objective can be configured to produce a first focal plane of the optical sighting system coincident with the first surface of the reticle prism. The display coupling prism is configured to direct display light toward the eyepiece.

Abstract: A system for retaining an optical member about a vehicle is disclosed. The system can comprise a mount, an optical member having a first end and a second end, and a primary retention system operable to secure the second end of the optical member of the mount. The system can further comprise a secondary retention system. The secondary retention system can comprise a retaining clip coupled to one of the optical member and the mount, adjacent the second end of the mount. The retaining clip can comprise at least one aperture therethrough. The secondary retention system can further comprise a pin coupled to the other of the optical member and the mount. The pin can extend through the aperture of the retaining clip. The secondary retention system can activate to cause the pin to engage the retaining clip upon movement of the optical member relative to the mount and at least partial failure of the primary retention system.

Abstract: A switch assembly is provided for optical sight activation. The switch assembly includes a shoulder mounted device comprising an actuatable portion and a stock, an electrically powered optical sight disposable on the shoulder mounted device in alignment with the actuatable portion, a switch disposed in the stock and actuatable to activate operations of the optical sight and circuitry by which the optical sight and the switch are electrically coupled.

Abstract: A radar system including a narrowband radar receiver configured to receive pulsed radar return signals and a wideband receiver configured for receiving wideband signals. A noise data processor is configured to identify impulse noises by analyzing wideband signals received by the wideband receiver and a radar processor is configured to cancel the identified impulse noises from pulse signals received by the radar receiver. The wideband impulse noises utilized to cancel noise from the pulse signals corresponds to the same time period sweep of detection as that of the pulse signals.

Abstract: A retrodiction tracker and related techniques and system are described. The technique extends the track range of an inbound target, initially detected with a low signal-to-noise ratio (SNR) (or initially detected with signals having a low probability of detection) to that of an outbound target where the low SNR detection is being associated with a confirmed, established, track. Retrodiction and backward propagation are being combined with historical plot-to-track association to significantly enhance the tracking capability of a radar.

Abstract: A close quarters battlefield (CQB) sight is provided. The CQB sight includes an optical sighting element and a base plate to which the optical sighting element is integrally coupled. The base plate includes a flange and a mounting surface formed to complement a mounting surface of another optical sighting element. The flange is configured to be fastened to the another optical sighting element such that the mounting surfaces abut and the optical sighting elements become co-aligned.

Abstract: Aspects are generally directed to a high speed pupil detection system and method. In one example, the method includes receiving optical radiation reflected from an eye at one or more pixels of an optical sensor, reading-out a value of each of the pixels in a plurality of lines to progressively generate an image frame of a video image stream, the value of each of the pixels being based on a flux of the received optical radiation, identifying a first chord within a first line of the plurality of lines, identifying a second chord within a second line of the plurality of lines, the first chord and second chord being separated by a subset of the plurality of lines, and determining a location of a center of a pupil of the eye based on a two chord crossing of the pupil with the first chord and the second chord.