Prism fiber reading tube

A prism fiber reading tube (PFT) for fast facsimile has been developed. It features a new type of prism-shaped glass fiber which makes direct contact reading possible. This newly developed tube is capable of reading opaque original manuscripts, a procedure not possible with an ordinary fiber-optics tube. By electronic scanning, a manuscript can be read at television scanning speeds. The resolution obtained is about 10 lines/mm and the light efficiency is about 5 times as high as that of a conventional flying-spot scanner using an f/1.8 lens with unity magnification.