Hand Held Products 3700 CCD manual CCD Operation and BAR Code Scanning a, Objectives

CCD OPERATION AND BAR CODE SCANNING A

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.

LED

Reflector

LED Pulse

Generator

Bar

Code

SymbolCCD

Sensor

Decoding/Interface

	Aperture	Power Supply,
		Digitizing,
Lens		Microprocessor,
		Signal
		Processing,
		and Control
		Circuitry

Cable

Modular

Bar CodeConnector

Label

Image

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.

CCD Operation and Bar Code Scanning A–1