Design and implementation of a 3D-LSI character recognition image sensor

A four-story structured character recognition image sensor has been implemented with three-dimensional LSI technology, integrating 55-thousand diodes and 0.22-million transistors on a 14.3-mm square single die. Three-dimensional LSIs will achieve very high performance by exploiting the structural parallelism by way of the inherent parallelism of the algorithm. The chip, which is the second-step prototype of the Intelligent Image Sensor, is able to sense 12 characters of an image at the same time and recognize 64 kinds of characters containing the alphabet in upper and lower case, Arabic numerals, and some symbols, each consisting of a 10*14 bit matrix. The present chip allows a 20 times larger degree of data parallelism in image computation and a considerably higher speed of recognition in data matching compared with a previous chip. The efficiency of the chip has been verified. >