14. OPTICAL FINGERPRINT SCANNERS

A. Problem/Issue

A biometrics technology company needed assistance with a mechanical palm and fingerprint scanner that they were developing for the Minnesota Highway Patrol to be used in squad cars. They were having difficulty with the mechanical component assembly moving slightly resulting in unreliable/unpredictable pixel scan. Also the assembly suffered from heat distortion during the machining process.

B. Analysis

We research precision components that were used including linear slides, precision ball screws, and support frames. We located vendors that specialized in precision casting machining, and precision equipment components. We changed the frame design from a component-based assembly to a single piece casting with the features machined in.

C. Solution/Results

We re-designed the product using new components and began to test using a small laser clamped to the fixture. We measured the variation in the position of the laser spot over 60 feet away on the far wall of the assembly area. The variation was within tolerances and the new design was accepted. The product went on to be a major contributor to company earnings.