Abstract: A laser collimator for collimating optical elements of a viewing device, such as a telescope. The laser collimator includes three or more lasers positioned on a plane in front of the optical elements of the viewing device for generating three or more respective incident laser beams directed towards the optical elements to simulate a large aperture coherent light; a reflecting mirror positioned at an eyepiece of the viewing device for reflecting the three or more incident laser beams; and a target display on the same plane or a plane parallel to the plane on which the three or more lasers are positioned for displaying the three or more incident laser beams reflected from the reflecting mirror and the optical elements of the viewing device, as three or more respective dots.

Abstract: An adapter clamp for clamping an adapting tube. The adapter clamp includes: an adapter tube; a first resilient ring placed in the inner circumferential surface of the adapter tube and including elastic material for expanding inward and clamping to the outer surface of the adapting tube; a hollow adjustment ring configured to be threaded to the inner surface of the adapter tube to generate a displacement force; and a compression ring providing minimum friction resistant for translating the displacement force from the threading hollow adjustment ring to a longitudinal compressing displacement of the first resilient ring, causing an inner surface of the first resilient rings to fit to the outer surface of the adapting tube. The adapter clamp also includes a second resilient ring placed in the inner circumferential surface of the adapter tube; and a spacer placed on the inner circumferential surface of the adapter tube.

Abstract: An adapter clamp for clamping an adapting tube having an inner surface. The adapter clamp includes: an adapter tube having an inner circumferential surface; a first resilient ring placed in the inner circumferential surface of the adapter tube and comprising of elastic material for expanding inward and clamping to the outer surface of the adapting tube; a hollow adjustment ring configured to be threaded to the inner circumferential surface of the adapter tube to generate a displacement force; and a compression ring providing minimum friction resistant for translating the displacement force from the threading hollow adjustment ring to a longitudinal compressing displacement of the first resilient ring, causing an inner surface of the first resilient rings to fit to the outer surface of the adapting tube.

Abstract: An adapter mount for attaching to a fitting tube includes an adapter tube having an outer circumferential surface; a first expandable ring placed on the outer circumferential surface of the adapter tube and comprising of elastic material for expanding and fitting to the inner surface of the fitting tube; an adjustment ring configured to be threaded to the adapter tube to generate a rotational threading force; a compression ring for translating the rotational threading force from the adjustment ring to a longitudinal compressing displacement of the first expandable ring, causing an outer surface of the first expandable ring to fit to the inner surface of the fitting tube; and a stop attached to the adapter tube for preventing the adjustment ring from separating from the adapter tube.

Abstract: A laser collimator includes an optical lens having an optical axis; a sliding lens holder for housing the lens having a longitudinal opening parallel to the optical axis; a stationary lens holder ring for fitting to the front of the sliding lens holder and having a protruding key for receiving the longitudinal opening; and a focusing ring movable along the optical axis, wherein the protruding key placed within the longitudinal opening prevents the sliding lens holder from rotating.