Polymer magnetic scanners for bar code applications

Abstract

Resonant mode polymer-based electromagnetic scanners are developed for barcode reading applications. The electromagnetic scanner consists of a mirror suspended by a polymer cantilever beam, a permalloy sheet attached to the mirror, and an external coil to generate the driving magnetic field. The simple fabrication process involves polymer molding and electroplating of magnetic material, yielding inexpensive devices suitable for high volume manufacturing. Mechanical and magnetic modeling of the device as well as analytical, numerical and experimental results are presented. A barcode reading system is demonstrated successfully using this inexpensive, easy to manufacture scanner. Fabricated cantilever scanners achieve an optical theta-D product of 123 degrees mm at 56.5 Hz, consuming an actuation power of 168 mW. 2D actuation of the cantilever scanners is also demonstrated.