CCD / Cell / Character / Character Density / Character Set / Checkdigit / Code Type / Continuous / CPI

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z - Back to Glossary Index - Previous

CCD

Charge Coupled Diode.

CCD readers use an array of hundreds of tiny light sensors lined up in a row in the head of the reader. Each sensor measures the intensity of the light immediately in front of it. A voltage pattern identical to the pattern in a bar code is generated in the reader by sequentially measuring the voltages across each sensor in the row. The important difference between a CCD reader and a pen or laser scanner is that the CCD reader is measuring emitted ambient light from the bar code whereas pen or laser scanners are measuring reflected light of a specific frequency originating from the scanner itself.

Cell

This term is used as a minimum unit of the 2-dimensional symbol.

Character

The combination of some black/white bars to express each of alphabet, numeric, marks, etc.

Character Density

Generally given as the number of characters per inch (cpi), This dimension is the length, in linear inches, required to encode one character.

(See also CPI)

Character Set

The total number of characters (alphabetic, numeric, symbols) that a certain bar code symbology can express. Some character sets can express numerics-only, numerics and symbols, numerics, alphabets and marks etc.

Checkdigit

Digits checked to determine if data scanned from the bar code is being misread. When a character is scanned incorrectly, usually caused by a void or spot on the label, the checkdigits helps to determine that the information is, in fact, incorrect.

(See the Checkdigit page for more information)

Code Type

There are two code types used for bar codes: Continious type and Discrete type.

Common continuous type bar codes include EAN, Interleaved 2 of 5, CODE-93, CODE-128. Its character density is high, but is very difficult to print.

Common discrete type bar codes include, NW-7 (CODABAR), CODE-39, etc. Its character density is comparatively lower than other "higher-quality" bar code symbologies and is easy to print.

• Continuous Type (Code-128):



• Discrete Type (NW-7 (CODABAR)):

(See continuous, and discrete)

Continuous

One of two bar code, code types.

(See Discrete)

CPI

Characters Per Inch.

Is the number of characters that will fit on an inch of a printed line.

(see character density)

CCD / Cell / Character / Character Density / Character Set / Checkdigit / Code Type / Continuous / CPI

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z - Back to Glossary Index - Previous