Anti-Theft Device for Portable Instruments
Original Publication Date: 1984-May-01
Included in the Prior Art Database: 2005-Feb-03
Portable instruments, such as personal computers, are obviously vulnerable to theft or tampering, particularly in school environments. The device described here is designed to prevent such activities. Referring to the block diagram in Fig. 1, the device, indicated at 1, comprises tape 2, for attaching it to the inside of the enclosure (not shown) of the instrument to be protected, an arming switch 3, an audible alarm 4, a tilt or movement detector 5, and a battery or other internal power source 6. Details of the detector and its operation are shown in Figs. 2-4. The detector consists of a hollow plastic cube having slightly concaved interior walls 8 (Fig. 3) on each of its six sides. Each wall contains a printed circuit pattern 9 of discrete, electrically separated lands.