Analog Circuits Cookbook, 2nd Edition

5

Opto

Sensing the position

Linear optical imager

This item describes an economical optical line imager with 64 point resolution. Applications abound: with some arrangement for vertical scanning, it would even make a rudimentary TV camera, with twice the resolution of Baird’s pre-second world war TV system!

A common requirement in industry, especially with the advance of automation, is position sensing, allied to position control actuators of various kinds. For the simpler jobs, discrete photodetectors, vane switches and the like suffice, but for critical applications, a progressive rather than an on/off indication of position is required. The CCD imaging devices can be used for position sensing, but require several different supplies and auxiliary ...