Passive Sensing Array

Fidelica’s sensor has 256 rows and 256 columns of resolution, and thus contains over 65,000 pixels. Although there are so many sensing elements, the high contrast, binary nature of the pressure sensing technique allows for use of a fully passive sensor array. That is, while other fingerprint sensors may rely on active elements, such as transistors, in the array, the Fidelica fingerprint sensor only needs passive elements to fully, and effectively, image a fingerprint.

In keeping with the FBI’s 500dpi standard for fingerprint imaging, sensor elements are placed at a 50 micron pitch, resulting in a 508dpi sensor. At a 256 x 256 resolution, the Fidelica sensor images an area of approximately 0.5” x 0.5.”

Benefits:

The use of a passive sensing array differentiates Fidelica’s fingerprint sensor from competitive devices in multiple regards. Passive electronics are inherently:

• Power efficient, both in standby and active imaging.
• Robust, insensitive to various types of damage. This is especially true when considering ESD, an ever-present risk in touch-interface devices.
• Manufacturable, fundamentally enabling Fidelica’s ability to create sensors on a flexible substrate.