US 8,985,449 B2 · Magnetic stripe reader

Abstract

The invention relates to a magnetic stripe reader, and more particularly, to systems, devices and methods of directly extracting binary information embedded in a magnetic stripe using simple analog and digital signal processing techniques. Once information stored in the magnetic stripe is extracted as a F-2F waveform by the magnetic stripe reader, peaks, valleys and mid-level transition points between every consecutive peak and valley are detected. A peak-to-peak period and an average time are directly derived to determine whether the corresponding peak-to-peak transition is associated with a binary bit of “1” or “0”. This magnetic stripe reader spares a need for a multi-bit analog-to-digital converter (ADC) and a large memory, and thus, constitutes a simple and self-contained solution that may read out the binary information stored on the magnetic stripe with reduced power consumption and improved cost efficiency.

Claims20

Dependent claims

A magnetic stripe reader, comprising:

a stripe interface, coupled to generate a F-2F waveform from binary information stored in a magnetic card;
a zero-cross detector, coupled to the stripe interface, the zero-cross detector detecting a plurality of zero cross events when the F-2F waveform crosses a mid-level transition point located between each adjacent peak and valley pair;
a peak detector, coupled to the stripe interface, the peak detector generating a peak detect output to track the F-2F waveform as it reaches each peak and valley;
a frequency analyzer, coupled to the zero-cross and peak detectors, the frequency analyzer calculating a plurality of peak-to-peak periods for a plurality of adjacent peak and valley pairs, and deriving a bit time based on the plurality of peak-to-peak periods;
and
a bit decoder, coupled to the frequency analyzer, the bit decoder generating a stream of digital data according to the plurality of peak-to-peak periods and the bit time.

3 more elements

A method of converting a F-2F waveform to a stream of digital data, comprising the steps of:

tracking a plurality of peaks and valleys in the F-2F waveform, the F-2F waveform alternating between peaks and valleys at two frequencies including a first frequency and a second frequency that doubles the first frequency;
calculating a plurality of peak-to-peak periods for a plurality of adjacent peak and valley pairs;
deriving a bit time based on the plurality of peak-to-peak periods, the bit time being used to differentiate a bit of “1” and a bit of “0”;
and
generating the stream of digital data according to the plurality of peak-to-peak periods and the bit time, wherein a peak-to-peak period at the first frequency is associated with a bit of “1” and two consecutive peak-to-peak periods at the second frequency is associated with a bit of “0”.

2 more elements

Dependencies are inferred from the claim text.

Magnetic stripe reader

Life of this patent

Magnetic stripe reader

Life of this patent

Abstract

Claims20