Sensor Format and Size

A large area sensor is indispensable for reliable system operation

Sensor Formats

Fingerprint sensors can be classified as swipe or area sensors. 

A swipe sensor requires the user to sweep their finger over the (smaller, line-shaped) sensor area in a consistent and uniform movement. 

The area sensor typically has a rectangular shape. It is more intuitive because the finger just has to be placed flat on the sensor.

Background & Current Situation

Historically, area sensors include bulky optical devices known from border management and criminal AFIS (Automated Fngerprint Identification System). Their size makes them unsuitable for mass-market applications like smartphones or notebooks. 

In contrast, silicon area sensors are flat and can be integrated into portable devices. However, their key disadvantage is the cost of silicon and the resulting increased sensor price.

These deficiencies led to the development of swipe sensors. Using only a fraction of the silicon, a swipe sensor can produce images larger than its surface. Unfortunately, swipe sensors require a significant user learning curve and have proven unreliable in many applications. In fact, industry experts claim that less than 2% of sensors shipped in notebooks have ever been used. Microsoft labels the swipe sensor format "inconvenient" and "unreliable" (stated during the launch of Windows 8.1 in June, 2013).

Currently, some vendors are developing small area sensors as a compromise between reliable and convenient operation and component cost. This small size will for many users result in false rejections and low user acceptance.  

The NEXT Approach

Instead of sacrificing the vitally important sensor size, NEXT has developed a sensor that can be produced more efficiently with a proven mass-production process. This uniquely combines a large area sensor at a cost level suitable for mass market applications. It is convenient to operate while costing only a fraction of comparable silicon area sensors. Making quality sensors affordable also facilitates individual devices rather than public sensors that many people find uncomfortable to touch.