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

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CCD

Charge Coupled Diode. Memory device which convert the light to the electric signal by the matrix of many particles on the silicon basis. Used for the barcode recognition by the hand scanner.

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Cell

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

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Character

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

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Character Density

The maximum of readable characters in the regular length. (See CPI)

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Character Set

the type of characters that the barcode can express.
There are some character sets such as numerics-only, numerics and marks, numerics and alphabets and marks, including full-ASCII control code, variable according to the type of the barcode.

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Checkdigit

The checking digits for avoiding the misreadings.
When the character is recognized as another, by the influence of the void or spot, the checkdigit helps to find it, if added.

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Code Type

There is two code type in barcode: Continious type and Discrete type. In continuous type, there are EAN, Interleaved 2 of 5, CODE-93, CODE-128. Its character density is high, but it is difficult to print. In discrete type, there are CODABAR, CODE-39, Straight 2of5, etc. Its character density is comparatively low, but it is easy to print; so often printed by personal printer, and used for number printing. (See continuous, discrete)

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Continuous

Continuous type is one of the code type of barcode.
The last space character has a meaning, as a white bar. (See Discrete code type)

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CPI

Characters Per Inch. The maximum characters of readable size, in 1 inch. (see character density)