(under subclass 454) Subject matter wherein the coded indicia is in the form of invisible markings which are made visible by illumination by an appropriate source and including means to analyze signals representative of the indicia.
(1) Note. Included here are devices that sense records encoded with fluorescent, etc. material, which records are illuminated by infrared or ultraviolet light sources.
(2) Note. The subject matter in this subclass and those indented hereunder differs from that found in Class 250 in that the light detected is converted to an electrical signal which is further processed by particular circuitry, the particular circuitry including the generating and utilization of timing and sync signals, the storage of signals, and means to perform counting operations.
SEE OR SEARCH THIS CLASS, SUBCLASS:
491, for records encoded with fluorescent, phosphorescent, or other radiation emitting substance.
SEE OR SEARCH CLASS
250, Radiant Energy,
336.1+, for invisible radiant energy responsive systems, per se, and subclass 271 for invisible coded record sensors, wherein no processing circuitry as outlined in (2) Note is included.
