Fingerprint Scanners work in smartphones
The finger print scanner technology is not new. We have been seeing it since 2011 in the mobiles and we found the first mobile to use this technology was Motorola Atrix using this technology and later this security technology for discontinued for some reasons and now iPhone 5S revived the use of this security system once again. It was not discontinued because it was not effected but more efficient systems were found out and used. In this article we see how the finger print scanner technology works.
There are mainly two methodologies work; Optical Scanner and Cleaver Capacitor circuits.
Optical Scanners
Optical scanner compare the finger prints like comparing the two pictures but it defers that the digital cameras are used with electrical charge and the picture thus formed and comparison is made. The charge couple system is in fact light sensor system that carry the light sensitivity diodes named photosites and they generate electrical signals by deducting light. The different level of lights create different strength of charge in each photosite whereas each photosite diodes is single pixel of the complete image and the small photosites on the sensor find out the resolution of the image and compare it with the resolution already recorded. More pixel density will give more accurate result.
For reference of accuracy level we can take the example of iPhone 5S sensor having 500ppi density with Galaxy S4 having 441ppi. Obviously iPhone5S will give better results as compare to Galaxy S4. Surprisingly when we press our thumb on the scanner there is no bright light like sun and to eliminate the surface of the thumb we have LEDs which eliminate the surface of the thumb to help create an image. The lines and the gap between them create different levels of light and very accurate picture is generated to find out the difference in the level of light. This optical scanner system actually compares the minutest difference in ridges and curves and compares with already registered image. The wonderful thing is accuracy in the reading of minutest differences.
Capacitance Scanner
In this system no image is generated but here we have capacitors and Op-amp circuits which generate electrical signals. To scan the small area in details needs a large no of electronic components which is quite difficult and costly, reducing its usage. The signals created by these capacitors are amplified to enlarge them sufficiently big and enabling comparison. It involves two layers of capacitors and conductor plates insolated from each other.
Since the finger prints are unique in case of each individual and the difference between each finger print is very minute. To compare and distinguish them electronically needs very pre size hardware and software processing. Complex algorithms are used for analyzing the pattern and bringing out the accurate results.
, 2015-12-25 07:21:25 Like : 0 , DisLike : 0 Comments : 0
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