Leather fault marking - has balls in quality zones with structured flats

摘要

To mark fault zones in natural leather, a number of balls (Ku) with flat zones are placed at different quality zones. The flattening of the balls (Ku) has a selected radius (r) so that the projection surface and the smallest possible viewing angle (alpha) always form a circle with the radius (r). The camera (Ka) is at a vertical gap (b) from thge laying surface (E) and at a horizontal gap (a) to the ball (Ku) in view. The viewing angle (alpha) is set by tan alpha = a/b and alpha = arctan a/b. The stretch (x) from the ball centre to the standing surface is x = sine beta where beta is 90 deg. - alpha, and sine beta = cosine alpha. The max. permissable height (h) of the flat is computed as h = r-x and h=r(l-sine beta) = r(l-cosine alpha). The stretch (h) must always be shorter than the theoretical value, to allow for corrugations. USE/ADVANTAGE - The system is for marking different quality zones on the surface of natural leather, to show different fault degs., which can be identified by a camera without misinterpretation.