| 摘要 |
PURPOSE:To improve rising on a highlight side and the reproducibility of a shadow part and to obtain the excellent expression of gradation by drawing many parallel white lines and parallel black lines which have fixed line width and fixed number of lines which are near to a resolution limit on a transparent base so that they may cross each other to be in a meshed state. CONSTITUTION:A mesh pattern formed by orthogonally crossing many white lines 2 with each other is printed on the surface of the transparent clear base, and the black lines 4 forming a cross are printed in a state where their directions are respectively arranged in respective transparent parts 3 enclosed by the white lines 2. The line width and the number of lines of the white lines 2 and the black lines 4 are set at a fixed value near to the resolution limit in a copying machine. In the case that this film screen is set so that the white lines and the black lines form the angle of 45 deg. with respect to a scanning direction and a consecutive original is copied through the film screen, the crossed part 6 is a little reproduced on the highlight side and black minute points are formed. On the other hand, the crossed part 5 is a little reproduced on the shadow side and white minute points are formed, thereby obtaining the excellent expression of gradation. |
