Functions of our Plate Scanner DEMIA in Auto-Preset Inking System and Existing State of the Utilization in Japan

We have successfully developed, for the first time in the world, an auto-preset inking system for offset printing including the plate scanner (DEMIA). The important factors for the development of the plate scanner include: (1) Ability to measure accurately the image areas of various printing plates. (2) Ability to produce, with simple operation, data for various types of printing presses. The important factors for the development of the plate scanner include: (1) Ability to measure accurately the image areas of various printing plates. (2) Ability to produce, with simple operation, data for various types of printing presses. For attaining these purposes, a light source and a sensor were selected from the spectroscopic characteristics, and with the optical structure appropriately conceived, the accuracy of within +/- 5 percent was achieved in measuring image area. Also, it has been made possible to store the data of 32 types of printing presses concerning the plate size and the number and pitches of the ink fountain keys, so the information of the image area correspond to a specific press can be produced with simple key operation. A total of 90 sets of this system are now in operation as of the March 1983 (including 60 DEMIA's), thus contributing to a quick printing start and saving waste at the same time.