Both FPC’s area sensor and swipe sensor are based on patented proprietary technology, which offers several strong advantages such as an acknowledged high image quality, programmable pixel elements and 256 gray scale values from every single pixel element. The sensors contain small capacitive plates, each with their own electrical circuit embedded in the chip. The sensors use FPC own method HSPA (High Sensitive Pixel Amplifier) which allows each pixel element in the sensor to detect very weak signal, which improves image quality for all types of fingers.
Extremely weak electrical charges, sent via the finger, are created, building a pattern between the finger’s ridges or valleys and the sensor’s plates. Using these charges the sensor measures the capacitance pattern across the surface.
FPC’s HSPA-method also allows a patented protective coating, 25 to 30 times thicker than other suppliers, that helps FPC’s sensors to withstand well above European Community Standard Class 4 requirement of 15kV for static electricity (ESD) as well as wear and tear.
Capacitance is the ability to hold an electrical charge. FPC’s sensor contains tens of thousands of small capacitive plates, each with their own electrical circuit embedded in the chip. When the finger is placed on the sensor extremely weak electrical charges are created, building a pattern between the finger’s ridges or valleys and the sensor’s plates. Using these charges the sensor measures the capacitance pattern across the surface. The measured values are digitised by the sensor then sent to the neighbouring microprocessor.
The surface of a capacitive sensor is a neat array of plates, able to measure the capacitance between these plates and the fingerprint contour. This can be done directly by applying an electrical charge to the plate;
The latter method, used by FPC is called the Active measurement method, sometime referred to as Reflective or Inductive capacitive measurement, and it brings several advantages. Using the programmable logic internal to the capacitive sensor configuration it is possible to read off and adjust the sensor reception to different skin types and conditions. Another important benefit is that the strengthened signal communications between the fingerprint surface and the sensor plates allows for the introduction of strong, protective coating layer, up to 25-30 times thicker than other suppliers, on the sensor surface. This enables FPC , as one of the very few sensor vendors, to sustain up to and well above the requirement for 15kV electrostatic discharge (ESD), as well as wear cycle tests for more than one million touches to the sensor.