MOIRE INSPECTING DEVICE FOR PHOTOENGRAVING

摘要

PURPOSE:To inspect simultaneously four kinds of moires by using a moire simulator in which four kinds of patterns for inspecting moires are recorded in the superposed state with different colors to project the moire simulator or the real image of a reflected original on the other and superposing optically the same. CONSTITUTION:Four kinds of the patterns for inspecting moires having the same patterns as the patterns of respective contact screens for black, magenta, cyan and yellow to be used in the stage of photoengraving are recorded in the superposed state with respective colors. The moire simulator 63 is illuminated by the illuminating light from a lamp 58. The pattern for inspecting moires and angle scale are projected by a projecting lens 47 onto the reflecting original 45 imposed on a stage 42. A base 64 is rotated to rotate the pattern for inspecting moires recorded thereto. A holder 70 is then slided and the point where the moires disappear is found by shifting each slightly the moire simulator 63. The rotating angle and the shifting rate of the focus in this stage are read from the scale.