ANORDNING FOR METNING AV PUNKT-PROCENTTAL

摘要

In a printing process in which tones are produced by dots of various sizes, the "dot percentage" affects the quality of printed matter. A dot percentage measuring device comprises microscope section 10 and a display section 20 formed as one unit. The area to be assessed on test piece 6 is identified through the microscope section. Half-mirror 12 directs part of the light transmitted through the test piece to photoelectric converter 23 and the electrical output of the converter is displayed on a meter 22. The light passed through the test piece is proportional to the dot percentage. A correction circuit to correct for the non-linear relationship between light transmittivity and dot percentage is also disclosed.