Symbol LS7708 - Page 338

Glossary - 4 LS7708 Scanner Product Reference Guide
Scan 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.
Space The lighter element of a bar code formed by the background between bars.
Specular Reflection
The mirror-like direct reflection of light from a surface, which can cause difficulty
decoding a bar code.
Start/Stop Character
A pattern of bars and spaces that provides the scanner with start and stop reading
instructions and scanning direction. The start and stop characters are normally to the
left and right margins of a horizontal code.
Substrate A foundation material on which a substance or image is placed.
Symbol
A scannable unit that encodes data within the conventions of a certain symbology,
usually including start/stop characters, quiet zones, data characters, and check
characters.
Symbol Aspect Ratio The ratio of symbol height to symbol width.
Symbol Height
The distance between the outside edges of the quiet zones of the first row and the
last row.
Symbol Length
Length of symbol measured from the beginning of the quiet zone (margin) adjacent
to the start character to the end of the quiet zone (margin) adjacent to a stop
character.
Symbology
The structural rules and conventions for representing data within a particular bar code
type (e.g. UPC/EAN, Code 39).
Tolerance Allowable deviation from the nominal bar or space width.
UPC
Universal Product Code. A relatively complex numeric symbology. Each character
consists of two bars and two spaces, each of which is any of four widths. The
standard symbology for retail food packages in the United States.
Visible Laser Diode
(VLD)
A solid state device which produces visible laser light.