Document processing5-6 Generic MICR Fundamentals GuideOptical reader sortersOptical readers typically use a light source and some type ofphotosensitive matrix array to convert an image of the characterinto a set of electrical signals. Optical readers that can interpretthe characters can be used to input data into an automatedreading system. They are frequently used in reject repairequipment.Dual read magnetic reader sortersSome reader sorters use a dual read approach, in which tworead stations magnetize and read the entire clear band area ofthe document independently.The simplest dual read reader sorter uses two waveformreaders. Like single read waveform reader sorters, each MICRcharacter that passes through the read slot produces awaveform signal at each read station. The waveforms arecompared against the known waveforms of the MICR characterset, using different algorithms and circuitry in each station, todetermine which character was read.Another type of dual read reader sorter has one single slotwaveform read station and one matrix head read station. Thesingle slot reader compares the waveforms against the knownMICR character waveforms, and the matrix reader builds a digitalbit map for each character and compares that to knowncharacter bitmaps.With the dual read technology, the system compares the resultsof the first head read with those of the second. If a character canbe interpreted by only one of the read stations, the successfulreader result is used. If neither read station properly identifies acharacter, that character is rejected. Conflicting interpretationsbetween the two heads also causes character rejection.An important aspect of reject rate diagnosis is understanding therecognition mode used by a dual-read reader sorter. Processingperformance should be evaluated only in dual-read mode. Use ofdiagnostic settings to turn off one of the read stations, or to rejecton either station independently, inflates the reported reject rate.
