Abstract: Range finding devices and target object management systems each having one or more features that enhance their functionality. In some embodiments, a disclosed range finding device includes a target object location area calculation unit that defines near and far edges and side edges of a target location area. In some embodiments, a disclosed range finding device is a passive range finding device that inserts a scale marker into an output image, varies the size of the scale marker in response to user actuation of a scale input, and determines the size of the scale marker and an estimated range to a target object. In some embodiments, a disclosed target object management system includes a processing unit operable to manage new location records for existing and new target objects via target object registers. Other embodiments are disclosed, as are corresponding methods and software.

Abstract: A viewer for an optical data insertion device and a combined system comprising a viewer and an optical data insertion device. The optical data insertion device comprising a projector operable to project a visible image and a light guiding device operable to direct light from the projector into the viewer. The viewer comprising an objective lens, an eyepiece lens and a diffuser screen provided between the objective lens and the eyepiece lens.

Abstract: A viewer for an optical data insertion device and a combined system comprising a viewer and an optical data insertion device. The optical data insertion device comprising a projector operable to project a visible image and a light guiding device operable to direct light from the projector into the viewer. The viewer comprising an objective lens, an eyepiece lens and a diffuser screen provided between the objective lens and the eyepiece lens.

Abstract: A viewer for an optical data insertion device and a combined system comprising a viewer and an optical data insertion device. The optical data insertion device comprising a projector operable to project a visible image and a light guiding device operable to direct light from the projector into the viewer. The viewer comprising an objective lens, an eyepiece lens and a diffuser screen provided between the objective lens and the eyepiece lens.