Depending on improvement of All-Point-Addressable and High-resolution printer technology and software application technology in publishing area, the Computer CTS by digitalization of document (characters, photos and etc.) is making great progress instead of current CTS by Typography. This paper describe about Text-composition using digitalized characters and Digitalization of photos using requantization and halftoning with screening.
As the more CEPS (Color Electronic Prepress System) has come into wide uses, the more demands for integrating text processing capabilities such as text input and editting into a color scanner and CEPS, in addition to image processing such as page make-up for color pictures, are increasing. This paper describes how to cope with these increasing demands, using scanners and CEPS.
This paper outlines the phototypesetting systems which are able to output complete pages: both kan-ji text and graphics. Full pagenation systems are used in many applications: news papers, parts lists, reference books for students, etc.. But it is nessesary for the systems to improve cost-effectiveness to be used in all applications instead of paste-up systems. “Batch method” is used to compose and layout much volume of text and graphics for books, parts lists, etc., and “Interactive method” is used to make up complex commercial applications. Both CRT and Laser setters are now used to output text and graphics, but laser setters may be mainly used in near future.
As a part of consecutive research titled on the heading of this paper, a study on selecting of suitable oil-colors, which will be absorbed on the unsealed area of anodized aluminium plate, was carried out by the evaluation of critical surface tensions of dyed surfaces. As the results, it was found that the surface dyed by Neozapon blue, Neozapon yellow or Oil red showed the critical surface tension of 26dyn/cm to 30dyn/cm, and any of them were ink-receptive. It was ascertained that the oil-colors mentioned above had no affinity to sealed area of anodized aluminium plate. Further, the stabilization energy by the nondispersion forces on undyed surfaces were evaluated by the measurments of contact angles in three-phase system of water-hydrocarbon-sealed surface of anodized aluminium plate. It was consequently obtained that the stabilization energy of them were 7dyn/cm to 8dyn/cm.
Recently, register controllers which automatically control color to color registration in gravure presses are very popular in printing industry, but the controlling ability is regarded as insufficient. Therefore, we have developed the most efficient register controller which automatically calculates optimum correction values depending upon the construction of a printing press and printing conditions, then corrects the register error rapidly thereby reducing spoilage to a minimum. To make the most efficient register controller, first of all, we made the calculation model of a printing press and became to be able to simulate the phenomenon of a register error by a computer. Then we decided to control in PD control method and could obtain the optimum gains in PD control through simulating the phenomenon of a register error by changing printing conditions such as the pass length between the printing units, the compensator roller displacement velocity, the printing speed, the tension of the web and the radius of the gravure cylinder, affecting the register control. Finally, we have developed the controller that always controls registration in response to the construction of the printing press and printing conditions.
Due to excessive ink spitting over edge of ink rail, many stains and spots appear on the printed sheet in news printing. The mechanism of this trouble was discussed in relation to water absorption of ink. To simulate the flow of ink in printing process, the tack value was measured as a function of time with water drops continuously fed to ink over rollers of inkometer. The tack value suddenly dropped after a certain period depending on the type of ink and flow rate of water, because the slip between two rollers occurred by formation of water film over ink. The stronger the tendency to cause ink spitting, the shorter the period of stable operation is. Improper ink-and-water balance is primarily responsible for the trouble.
The printing quality monitoring system is a new inline high-speed inspection equipment for the checking of printing defects (scumming, hickey, mis-resistering, etc.) aiming to replace conventional manual operation. The system is composed of a CCD camera that takes the print pattern as image data, a xenon light source with optical fiber to the printed matter, an image data processing device for judging defects, and a display unit. This system includes the following features: (1) Complete surface inspection of all products. (2) High-speed inspection. (3) High-precision inspection.