Photoelectric scanning systems for reading data appearing in an angular

Abstract

There is disclosed a photoelectric scanner head for reading information pertaining to actual time, elapsed time or the like from a card or other record-bearing member, and for providing output signals that are a function of the information read; the output signals are used to obtain a useable electrical analogue of the information read from the member. The scanner comprises a rotatably driven body member mounting a source of light, read photoelectric devices and a switching circuit for retrieving information from the record member. A source of signals is supported by the body member and operably connected to the photoelectric devices by the switching circuit such that the source generates scanner output signals as a function of the information retrieved. Scanner output signals are detected, and in most disclosed embodiments, are used to controllably gate timing pulses into counters such that the counters provide on their outputs a raw electrical analogue of the information read from the record member. Means may be connected to the counters for correcting the analogue to account for error in the recording made on the record member.