Optical Reader Sorters; Dual Read Magnetic Reader Sorters - Xerox 6100BD - Phaser Color Laser Printer Fundamentals

Document processing

Optical reader sorters

Dual read magnetic reader sorters

5-6
Optical readers typically use a light source and some type of
photosensitive matrix array to convert an image of the character
into a set of electrical signals. Optical readers that can interpret
the characters can be used to input data into an automated
reading system. They are frequently used in reject repair
equipment.
Some reader sorters use a dual read approach, in which two
read stations magnetize and read the entire clear band area of
the document independently.
The simplest dual read reader sorter uses two waveform
readers. Like single read waveform reader sorters, each MICR
character that passes through the read slot produces a
waveform signal at each read station. The waveforms are
compared against the known waveforms of the MICR character
set, using different algorithms and circuitry in each station, to
determine which character was read.
Another type of dual read reader sorter has one single slot
waveform read station and one matrix head read station. The
single slot reader compares the waveforms against the known
MICR character waveforms, and the matrix reader builds a digital
bit map for each character and compares that to known
character bitmaps.
With the dual read technology, the system compares the results
of the first head read with those of the second. If a character can
be interpreted by only one of the read stations, the successful
reader result is used. If neither read station properly identifies a
character, that character is rejected. Conflicting interpretations
between the two heads also causes character rejection.
An important aspect of reject rate diagnosis is understanding the
recognition mode used by a dual-read reader sorter. Processing
performance should be evaluated only in dual-read mode. Use of
diagnostic settings to turn off one of the read stations, or to reject
on either station independently, inflates the reported reject rate.
Generic MICR Fundamentals Guide