Fingerprint sensing device using pulse processing

Details Fingerprint sensing device using pulse processing Fingerprint sensing device using pulse processing

2011-06-21

2011-06-21

Werner, Brian P (Department: 2624)

Image analysis

Applications

Personnel identification

Reexamination Certificate

active

07965877

ABSTRACT:
A fingerprint sensing device that measures the capacitance between an array of electrode plates and finger skin using pulse processing, in which pulse width rather than voltage level, is used for capacitance measurement and digital signal conversion. A pulse, the width of which is compared and adjusted with that of a reference pulse, is generated when voltage at sensing electrodes in discharging is compared with a reference voltage. The comparison results are then digitalized in a grade image sensor or output directly in a binary image sensor. The sensor can communicate with a CPU using serial communication, parallel communication, or memory map scheme. Since no A/D is used, there is no extra time and hardware cost for the conversion from analog signals to digital signals. Due to the pulse processing nature, the circuits can be configured insensitive to the change or fluctuation in voltage supply. This feature enables the sensing device work with a variety of voltages, and thus it can be better used in portable, battery powered or passive devices.

REFERENCES:
patent: 4283676 (1981-08-01), Shaw
patent: 6937031 (2005-08-01), Yoshioka et al.

Affiliated with

Also associated with

Rating

Fingerprint sensing device using pulse processing does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Fingerprint sensing device using pulse processing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fingerprint sensing device using pulse processing will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2628429