User manual

CCD Operation and Bar Code Scanning A–1

CCD OPERATION AND BAR CODE SCANNING

A.1 Objectives

This appendix describes:

• Reading and decoding a bar code symbol.

• Overview of how the SCANTEAM 3700 works, including a scanner diagram with

the main decoding elements listed.

• In–depth discussion of the operation of the scanner, including a block diagram and

discussion of the internal parts of the scanner, and a timing sequence diagram.

• Bar code basics and scanning tips.

A.2 Scanning and Decoding a Bar Code Symbol

The body of the SCANTEAM 3700 houses all the scanning elements, and

decoding/interface elements. Refer to Figure A.1.

Power Supply,

Digitizing,

Microprocessor,

Signal

Processing,

and Control

Circuitry

Cable

Bar

Code

Symbol

Bar Code

Label

Image

Modular

Connector

LED Pulse

Generator

CCD

Sensor

LED

Reflector

Lens

Aperture

Decoding/Interface

Pixel

Array

Figure A.1 Main Elements of the 3700 CCD Bar Code System

The SCANTEAM 3700 performs the following steps when scanning and decoding a bar

code symbol:

1. The scanner turns the LEDs (Light Emitting Diodes) inside the scanner ON, and the

light from the LEDs illuminate the bar code symbol.