1. Bar code scanner Department of Computer Engineering, M.S.P.V.L. Polytechnic College, Pavoorchatram. www.ustudy.in

2. Bar code Scanner www.ustudy.in

3. Introduction A bar code is an optical machine readable representation of data. Bar code scanner is an electronic device for reading printed bar codes www.ustudy.in

4. Operations of Bar code scanner Light Source Light Source Light Sensor Light Sensor ADC DSP To bar code software To compute r www.ustudy.in

5. Operation The light from the source is made to move over the bar code. The dark absorb light and white spaces reflect light. The reflected light is made to fall on a light sensor. www.ustudy.in

6. Light sensor www.ustudy.in

7. Cont., The light sensor generates a analog wave form that is used to measure the width of the bars and spaces in the bar code. The analog wave is converted to digital wave using analog to digital converter (ADC). www.ustudy.in

8. Cont., www.ustudy.in

9. Cont., www.ustudy.in

10. The output from ADC is given to the digital signal processor (DSP). The DSP processors the input signal and sends the signal to the bar code software. The software converts the electrical pulses into readable text and can be displayed. Cont., www.ustudy.in

11. The End …..Thank you…. www.ustudy.in