Why Miniaturize? The ideal detector should be as precise as you want and infinitely fast, but close to zero in price and size. We will show in the following text first of all what it is possible to achieve today regarding size. Due to the ever-increasing intensive use of high-performance electronic machine controls, a larger concentration of sensors can be observed. This should not, if possible, oblige the machine manufacturer to modify the mechanics just to provide space for detectors, it would be in fact illogical that the use of detectors makes the mechanics bulkier, therefore more expensive and even possibly less effective. This automatically results in the requirement for smaller and smaller detectors. This particularly concerns the proximity detectors used in large quantities, which we will deal with in the following text.