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.

The present application discloses a zoom lens assembly utilizing a novel extension spring configured to exert a biasing force on one or more lens cells during operation thereof. In one embodiment, the extension spring includes a spring body having a coil axis, a first spring end region having a first inner coil and a first outer coil formed on the spring body, wherein the coil axis of the spring body transitions from the first inner coil to the first outer coil. The extension spring further includes a second spring end region having a second inner coil and a second outer coil formed on the spring body, wherein the coil axis of the spring body transitions from the second inner coil to the second outer coil. An intermediate spring region having a plurality of intermediate coils extends from the first spring end region to the second spring end region.

The present application discloses a zoom lens assembly utilizing a novel extension spring configured to exert a biasing force on one or more lens cells during operation thereof. In one embodiment, the extension spring includes a spring body having a coil axis, a first spring end region having a first inner coil and a first outer coil formed on the spring body, wherein the coil axis of the spring body transitions from the first inner coil to the first outer coil. The extension spring further includes a second spring end region having a second inner coil and a second outer coil formed on the spring body, wherein the coil axis of the spring body transitions from the second inner coil to the second outer coil. An intermediate spring region having a plurality of intermediate coils extends from the first spring end region to the second spring end region.

A method of additive manufacture is disclosed. The method may include creating, by a 3D printer contained within an enclosure, a part having a weight greater than or equal to 2,000 kilograms. A gas management system may maintain gaseous oxygen within the enclosure atmospheric level. In some embodiments, a wheeled vehicle may transport the part from inside the enclosure, through an airlock, as the airlock operates to buffer between a gaseous environment within the enclosure and a gaseous environment outside the enclosure, and to a location exterior to both the enclosure and the airlock.

A method of additive manufacture is disclosed. The method may include creating, by a 3D printer contained within an enclosure, a part having a weight greater than or equal to 2,000 kilograms. A gas management system may maintain gaseous oxygen within the enclosure atmospheric level. In some embodiments, a wheeled vehicle may transport the part from inside the enclosure, through an airlock, as the airlock operates to buffer between a gaseous environment within the enclosure and a gaseous environment outside the enclosure, and to a location exterior to both the enclosure and the airlock.

A lens assembly includes a first lens group, a second lens group, a third lens group, a fourth lens group, and a reflective element. The first lens group is with refractive power. The second lens group is with positive refractive power. The third lens group is with positive refractive power. The fourth lens group is with refractive power. The reflective element includes a reflective surface. A light from an object sequentially passes through the first lens group, the second lens group, the third lens group, and the fourth lens group to an image side along an axis. The reflective element is disposed between an object side and the image side along the axis. Intervals of the lens groups are changeable when the lens assembly zooms from a wide-angle end to a telephoto end.

A method and an apparatus for collecting powder samples in real-time in powder bed fusion additive manufacturing may involves an ingester system for in-process collection and characterizations of powder samples. The collection may be performed periodically and uses the results of characterizations for adjustments in the powder bed fusion process. The ingester system of the present disclosure is capable of packaging powder samples collected in real-time into storage containers serving a multitude purposes of audit, process adjustments or actions.

A method and an apparatus for collecting powder samples in real-time in powder bed fusion additive manufacturing may involves an ingester system for in-process collection and characterizations of powder samples. The collection may be performed periodically and uses the results of characterizations for adjustments in the powder bed fusion process. The ingester system of the present disclosure is capable of packaging powder samples collected in real-time into storage containers serving a multitude purposes of audit, process adjustments or actions.

Optical zoom system comprising an image sensor, an objective having multiple refractive surfaces and a focus tunable lens which has a tunable optical power, an expansion unit which is arranged to alter a total track length, wherein in the total track length is measured from a first refractive surface of the objective to the image sensor along the optical path.

A method for designing an optical system for providing reliable, robust and successful realization of a distortion variation function is presented. In a preferred embodiment, the proposed distortion variation optical system includes at least two non-symmetrical elements, which are moving in the transverse direction. The proposed freeform lens contains two transmissive refractive surfaces. The freeform elements designed with this method have preferably a flat surface and a non-symmetrical freeform surface. The two plano-surfaces are preferably made to face each other, so that a miniature camera can be offered. The value of the non-symmetrical freeform surface is used to produce variable optical power when the two freeform elements undergo a relative movement in the vertical direction. Using this method, an optical system with an active distortion, smaller form factor, and better imaging quality can be obtained.