Electro-optical measurement and focusing apparatus

An electro-optical measurement apparatus comprising, a measurement station, a light source on one side of the measurement station, means to direct a beam of collimated light from the light source along an optical path through the measurement station, photo-detector array means disposed in the optical path from the measurement station, means to support an object to be measured at the measurement station in said optical path to block part of the light beam from the light source leaving transmitted portions of the beam to reach and activate corresponding sections of said array means, means to derive the dimension of the object in the optical path from the resulting activation of the array means, a screen, and an optical device on which light from the measurement station is incident having one area which directs light to the array means and another area which directs light to the screen, wherein the improvement comprises providing means to focus parallel light from the measurement station onto said one area of the optical device for directing said light onto the array means and providing further focussing means for focussing non-parallel light directed from the optical device onto said screen to create an image of the object being measured in the measurement station on the screen.