A novel digital electron-beam line scanner

A unique new electron-beam line scanner has been developed that has many advantages over both a conventional CRT flying-spot scanner and a laser line scanner. The extraordinarily simple construction consists of a thermal emission cathode, a pair of flat rectangular glass substrates containing thin-film patterns, and a target such as a phosphor. The substrates, assembled parallel to each other with a small gap, act, under digital input signals, to control a sheet beam of input electrons. All segments of the input beam except the desired one(s) are absorbed into the surface, and the remaining one(s) constitute the output signal beam. Inherent advantages of the line scanner over CRT scanners include digital addressing, high-resolution operation, multiple-beam and pseudo-random scanning, geometric invariance, very compact size, stability, ruggedness, no moving parts, high-speed, low-voltage switching, long life, and low cost. The principle of operation and the development status will be discussed.