Glossary - 9
QQuiet Zone. A clear space, containing no dark marks, which precedes the start character of a bar code symbol and follows
the stop character.
QWERTY. A standard keyboard commonly used on North American and some European PC keyboards. “QWERTY” refers
to the arrangement of keys on the left side of the third row of keys.
RReflectance. Amount of light returned from an illuminated surface.
Resolution. The narrowest element dimension which is distinguished by a particular reading device or printed with a
particular device or method.
RS-232. An Electronic Industries Association (EIA) standard that defines the connector, connector pins, and signals used to
transfer data serially from one device to another.
SScan Area. Area intended to contain a symbol.
Scanner. An electronic device used to scan bar code symbols and produce a digitized pattern that corresponds to the bars
and spaces of the symbol. Its three main components are: 1) Light source (laser or photoelectric cell) - illuminates a bar
code,; 2) Photodetector - registers the difference in reflected light (more light reflected from spaces); 3) Signal
conditioning circuit - transforms optical detector output into a digitized bar pattern.
Scanning Mode. The scanner is energized, programmed and ready to read a bar code.
Scanning Sequence. A method of programming or configuring parameters for a bar code reading system by scanning bar
code menus.
Self-Checking Code. A symbology that uses a checking algorithm to detect encoding errors within the characters of a bar
code symbol.
Skew. Rotation of a bar code symbol on an axis parallel to the symbol's length.
Space. The lighter element of a bar code formed by the background between bars.
Space Width. The thickness of a space measured from the edge closest to the symbol start character to the trailing edge
of the same space.
Specular Reflection. The mirror-like direct reflection of light from a surface, which can cause difficulty decoding a bar code.
Stacked Symbol (2-D Symbols). A 2-dimensional (2-D) symbol with sequences of linear (width-coded) data that are
stacked one upon another (i.e., PDF417).