Systems and methods for improving night vision systems are presented. Broadband multi-level diffractive lenses are used in place of either or both of the objective and eyepiece of traditional night vision systems. By using one or more broadband multi-level diffractive lenses, the size, weight, and weight distribution may be reduced or modified.

A night vision optical device includes an underlying device configured to be sensitive to light in a first spectrum, and to provide output light based on absorbing light in the first spectrum. The night vision optical device further includes a stacked device overlapping the underlying device. The stacked device includes one or more openings formed in the underlying device to form one or more transparent regions which are transparent to the light in the first spectrum to allow light in the first spectrum to pass through to the underlying device. The stacked device is sensitive to light in a second spectrum. The stacked device outputs light in the first spectrum to the underlying device as a result of absorbing light in the second spectrum. Thus, the underlying device outputs light based both on light passing through the transparent regions and on light output by the stacked device.

An eye shield has an attachment device configured to be coupled to an optical device. The attachment device includes a clamping ring that has an open position and a closed position. The eye shield further has a shield coupled to the clamping ring to pivot away and towards the clamping ring, the shield extends laterally from the attachment device and a locking element that is disposed on the clamping ring and configured to lock the clamping ring in the closed position. The locking element has a locked and an unlocked position, and when the locking element is in the locked position the clamping ring is in the closed position.

A helmet mount includes a latching plate defining a latching opening with wide and narrow portions and a notch. A latching spring below the latching plate urges a spring portion against the wide portion. The shaft of a first pin on an accessory mount is sized to fit in the narrow portion while its widened head only fits through the wide portion. The spring portion engages the widened head and prevents sliding within the narrow portion. The shaft of a second pin slides within the notch with its widened head preventing removal. A wedge may be slid against the spring to retract the spring portion allowing removal of the first pin. Electrical contacts on the helmet mount may engage electrical contents on the accessory mount to supply power to an accessory such as night-vision goggles.

A high etendue modular finite conjugate lens assembly has a zooming component with multiple lens groups, including four lens groups that each feature a doublet, and a lens attachment lens assembly comprising a fifth doublet, wherein the lens assembly is configured to exhibit between 0.45 and 4.65 mm.sup.2sr of etendue, and a ratio of highest to lowest magnification between 5.5:1 and 16:1, and a magnification of at least 2× at one or more points of a zoom range.

A modular finite conjugate zoom lens assembly with five lens groups each including a doublet, wherein two or three movable lens groups are disposed between a pair of static lens groups.

A mounting device having a mounting assembly for mounting a pair of goggles to a helmet is provided. The mounting assembly is configured to provide at least three degrees of freedom of movement using one or more actuation mechanisms for locking and unlocking a position of the mounting device. The number of actuation mechanisms is less than a number of degrees of freedom. In some aspects, the number of actuation mechanisms is one. A rotation base connects the mounting assembly to the helmet, and a goggle linkage connects the mounting assembly to the goggles. Various single actuation mechanisms, including a sliding mechanism, a friction-based wire/brake mechanism, and a floating friction brake mechanism, are provided.

A helmet-mounted display system includes a helmet; detachable binoculars; a mechanical arch securely mounted on the front part of the helmet, the arch comprising: a display device; an optical position-detection device; a binocular attachment assembly; a movable visor having the following two main positions: a down use position, applied when the binoculars are not mounted, the visor covering the pupil-expansion combiner and leaving the optical position-detection device uncovered; an up use position, applied when the binoculars are mounted, the visor being situated on the top of the helmet and leaving the optical position-detection device uncovered.

An eye shield for protecting a user's eye has a shield that includes an aperture. The aperture has a first central axis, a medial side, and a lateral side, and a gasket that is coupled to the shield and disposed within the aperture. The gasket has a second central axis. The first central axis is at an oblique angle relative to the second central axis.

A direct view display system (DVDS) and a method to operate it are provided herein. The DVDS may include: a variable optical power element (VOPE); a transparent active image source located with the VOPE on a common optical axis going from an outside scene to an eye position of a viewer; and a time division multiplexer (TDM) configured to control the VOPE and the transparent active image source, wherein the TDM is configured in a certain time period to cause the transparent active image source to be in a transparent state and the VOPE to exhibit no optical power, and wherein the TDM is configured in another time period to cause said transparent active image source to exhibit an image and said VOPE to apply non-zero optical power, for projecting the image onto the eye position at a desirable distance therefrom.