An objective lens unit includes an objective lens, a first rotary member, a second rotary member, and a drive section. The objective lens is provided with a correction ring. The first rotary member is mounted on the objective lens. The second rotary member engages with the first rotary member. The first rotary member has a first engagement portion. The second rotary member has a second engagement portion that is to engage with the first engagement portion. The second engagement portion is disposed at a part in the circumferential direction of the second rotary member. The second rotary member rotates to be positioned at an engagement position or a retraction position. The engagement position is a position where the second engagement portion engages with the first engagement portion. The retraction position is a position where the second engagement portion retracts from the first engagement portion.

A method and an apparatus of a powder bed fusion additive manufacturing system that enables a quick change in the optical beam delivery size and intensity across locations of a print surface for different powdered materials while ensuring high availability of the system. A dynamic optical assembly containing a set of lens assemblies of different magnification ratios and a mechanical assembly may change the magnification ratios as needed. The dynamic optical assembly may include a transitional and rotational position control of the optics to minimize variations of the optical beam sizes across the print surface.

A method and an apparatus of a powder bed fusion additive manufacturing system that enables a quick change in the optical beam delivery size and intensity across locations of a print surface for different powdered materials while ensuring high availability of the system. A dynamic optical assembly containing a set of lens assemblies of different magnification ratios and a mechanical assembly may change the magnification ratios as needed. The dynamic optical assembly may include a transitional and rotational position control of the optics to minimize variations of the optical beam sizes across the print surface.

Hardness testers having a pivoting body and capable of providing power to accessories on the pivoting body are disclosed. An example hardness testing device includes: a rotating carriage configured to: hold at least one of an indenter or an objective and at least one accessory; and rotate to selectively place the at least one indenter or objective or the at least one accessory in an operative position to operate the at least one indenter or objective or the at least one accessory; a carriage mount configured to support the rotating carriage; and an electrical contact block mounted stationary with respect to the carriage mount, the electrical contact block comprising a plurality of electrical contacts configured to make electrical contact with a counterpart electrical contact block of the at least one accessory coupled to the rotating carriage when the at least one accessory is positioned in the operative position.

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.

An embodiment of the disclosure provides a vision recovery training device, which includes a housing formed to be worn on a face around the eyes, a pair of rotation modules mounted to an inside of the housing, and a lens provided in each rotation module, at least one of the rotation modules including: a rotation disc; a magnetic body inserted in the rotation disc; and a sensor module provided in the housing at a radial position corresponding to the magnetic body.

An embodiment of the disclosure provides a vision recovery training device, which includes a housing formed to be worn on a face around the eyes, a pair of rotation modules mounted to an inside of the housing, and a lens provided in each rotation module, at least one of the rotation modules including: a rotation disc; a magnetic body inserted in the rotation disc; and a sensor module provided in the housing at a radial position corresponding to the magnetic body.

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.