Abstract: A method for detecting an diagnosing faults in printed circuit boards. Emissivity data and thermal image data of the various components of the board are obtained. The emissivity data is used to correct the thermal image data. The corrected data is converted to device space data, which is then input to a previously trained neural network. The output of the neural network indicates the location of the fault. The method includes an improved method for obtaining an emissivity map and a method for providing suitable neural network input.

Abstract: An electronic pricing display system for displaying pricing and other specialized information in real time on shelf display tags (18). Display tags (18) are battery operated and receive remotely transmitted infrared signals from optical heads (20) mounted on the ceiling of a store. A handheld electronic controller (22) may be carried by store personnel for obtaining information from or sending information to a selected wireless display tag (18). Pricing information from a main computer (10) is connected by an electronic interface (23) including a microprocessor (24) into a serial information stream having two separate frequencies for relay to the optical heads (20).