Glossary
G–8
retroreflector
A reflector, specially constructed,
which reflects energy back to the
source from which it came. It is also
known as a “corner reflector”.
reverse image
A symbol in which the normal dark
areas are represented in the light
areas.
S
scan
The search for a symbol or marks
which are to be optically recognized.
scan area
The area intended to contain a
symbol.
scan head, scanner
A device that optically scans bar
code symbols and converts the
optical information into digital or
analog form and sends it to a
decoder.
scanner rollover
A reset of the raster mechanism that
causes the rastering scan beam to
rollover, or continue its sweep, as
much as 360° until the mechanism
resets.
scanning curtain
The effective reading area (width x
height) of a moving beam scanner,
which is equal to its depth–of–field
and height–of– scan at a specific
operating range.
scanning range
The combined distance of optical
throw and depth of field.
self–checking
A bar code or symbol using a
checking algorithm which can be
applied to each character to guard
against undetected errors.
Non–self–checked codes may
employ a check digit or other
redundancy in addition to the data
message.
serial code
A bar code symbol typically used
with a fixed beam scanner where the
scanning action is caused by the
motion of the symbol past the
scanning head. The bits of the
symbol are evaluated one at a time
(serially).
skew
Rotation about the Y axis.
Rotational deviation from correct
horizontal and vertical orientation
may apply to a single character, line
or the entire encoded item.
space
The lighter element of a bar code
formed by the background between
bars.
space encoding
See interleaved bar code.
special symbol/character
In a character set, a character that is
neither a numeral, letter, or a blank:
for example, @ $ % ¢ & *.
spectral response
The variation in sensitivity of a
device to light of different
wavelengths.
To Next Page
Loading...
