Both of the theoretical and experimental analysis of the halftone image are reviewed in this paper. An approach is shown for evaluating the reflected light intensity from the surface printed solidly on which both of the macroscopic and microscopic fluctuations in ink thickness exist. The statistical nature propagating from microscopic fluctuation on dots to the average reflected intensity is also measured with the various analyzing techniques and equipments. The image processing systems composed of microprocessor have been effectively used for analyzing printed dots and press systems. This suggests that the micro-processor will be able to control the printing press by getting the information as an image if an analytical or statistical solution about the relations between perturbations in the printing process and the disturbance in printed results can be found out successfully.

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Various kind of measurement technologies, or automatic control technologies on printing machines, are recently developed and presented by printing press machineries, in order to improve the rate of operation for the printing machine. This paper describes an outline on electronic ink control systems, automatic dampening water control systems, automatic preset registration systems, automatic print quality inspection systems and so on.

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The tone reproduction of positive presensitized plates influenced by exposure and developing processes has been examined by computer simulation. With regard to the dot loss of the plate due to exposure, a very good agreement is obtained between experimental and calculated data by considering both the intensity distribution of incident light and the intensity attenuation of reflected light. The tone reproduction is varied by both the concentration of developers and exposure time. But the effect of the former is less than the latter. Good correlation is found also between dot area and narrow lines. Thus by checking the narrow lines, the tone reproduction on the plates can be administered.

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The solid density seems to be related to the quality of printing products. Optical properties of the solid-prints were analyzed with various densitometer. The solid density depended on areas ratio converted by the ink in the solid prints (coverage ratio) and average thickness and surface structure of the ink layer on the paper. The effects by surface structure were analyzed with measuring the polarizing solid density and occured in the high density region. The effects by coverage ratio measured with dot-area meter occured in the low density region. The effects by average thickness occured in the middle density region.

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Recently, a high speed offset printing has been achieved by adopting a UV curing system, which has not been used in intaglio printing. The printed line in the intagilo printing is so thick that UV ray cannot be penetrated deeply into the ink printed. The EB curing system is considered to be more suitable for this type of thick ink than the UV curing system. The main purpose of this study was the development of the EB curable vehicles involving mono and polyfunctional acrylates and their application to intaglio printing ink. It was found that the dose rate has to be kept as low as possible (below 1 Mrad) because of the prevention of paper degradation. The relation of the chemical structure and EB curing speed of the acrylate monomer and oligomer for the design of high speed curable ink was also derived. Then it was concluded from the measurements of physical properties such as flexibility, visco-elasticity, abrasion and viscosity that the strength and ink flow property of the ink cured by the EB radiation were sufficient for the use of the intaglio printing.

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Recently, hot air dryer for gravure printing has become popular. But generally speaking, its thermal efficiency is so low that it needs much energy. Therfore, in order to save drying energy, we've developed high thermal efficiency dryer. Our development has been accomplished after following two experimental work. One is computer simulation to make clear the ink drying mechanism and the others is trial manufactures and valuation tests to establish the high heat transfer coefficient nozzle. As a result of the newly found ink drying mechanism, we've got two conclusions as follows; (1) In the latter half of the dryer hood, the number of nozzles should be decreased, because hot air is less effective for drying in this area. (2) Exhaust gas should be recycled within the safe limit of the explosion, because as for the drying capability, high density solvent gas is so much useful as low density gas. And through nozzle experiment, we've established the punched plate nozzle of which heat transfer coefficient is 1.5 times as high as that of the conventional slit type nozzle. Thanks to this experimental result, we've developed new type dryer and installed it to our 8 color (700mm width) gravure press for flexible package printing, and consequently its energy has been reduced by half.

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For printing paper company, the paper evaluation of printing performance is very important daily and routine work. There is one evaluation method of GRAVURE printing performance, counting dot-miss after printing on LWC paper by GRAVURE test printer. In this method, up to present, we counted dot-miss one by one which were confirmed by man's eyes through the magnifying profile projector with dot size and density. So this method was taken much time and we were very tired with measuring. Moreover this method depends on only the judgement of the man who was measuring. Then we developed the following system which was applied Image-Processing technics. Everybody can measure dot-miss easily, quickly and clear. We made sure that the method of using this system replaced the old method (man eyes evaluation), and also this system makes standard of dot-miss evaluation.

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