Universal magnifying viewer for pocket calculators - has cylindrical lens and mirror adjustable for tilt and height

摘要

The universal magnifying viewer for pocket calculators comprises a cylindrical bar of optical glass or plastic which is positioned above the calculator display window. Light passing through the bar is reflected by an inclined mirror through a viewing screen near the top edge of the housing. An overhanging lip shields the screen from incident light. The calculator is placed on a stand to which the viewer is attached. The housing can be tilted to the required viewing angle by means of a knob and the height- and therefore the image size- adjusted by a clamping screw and slotted support bracket. An adjustable stop varies the veiwing aperture size according to the size of the observed numerals.