Earticle

Even if some kinds of software for halftoning such as raster image process program are on the market, most of them couldn`t apply to the new laser gravure cylinder making machine because they are closed the source program. In order to develop new laser gravure engraving machine, we were investigated new suitable halftoning software based on the mapping and equal density expansion algorithm that we are mapped. As the results of actual practice with Microsoft Visiul C++2.0 in 133Khz 64M ram IBM personal computer, we found that the new software for halftone generation for laser gravure engraving machine are available in new machine, and easily load and processing the graphic image for gravure hardcopy.

For the purpose of preparation of monodispersed spherical zinc oxide fine particles, an experimental research on the preparation of zinc oxide particles from zinc salts solutions by high temperature precipitation reaction was performed. Zinc oxide particles were precipitated from all the precipitation solutions tested if the precipitation temperature was higher than 60. As the precipitation temperature Increased until 80˚, the average particle diameter of zinc oxide particles decreased and the narrower particle size distribution were obtained. Spherical zinc oxide fine particles with relatively narrow particle size distribution were precipitated from the ZnSO⁴solutions with NaOH as precipitant. Final pH of precipitation solution had an effect on the amount of zinc oxide precipitated, but had no effect on the their particle size or size distribution.

Moisture content of printing paper and circumstance of printing room has great influence on the printing works. We have studied on the printability of domestic art paper according to the insufficient Korea weather. As the result, we found the printability of domestic art paper are much more affect by moisture content than any other printability coefficients, especially print density and hygroexpansivity decrease with moisture content increase.

Main -chain dimer liquid crystal having structure such as NCO(CH2)nOCN(CBA-9,10_and BrO(CH2)nOBr(BrBA-9,10) with n=9,10 were synthesized. CBA-9 and 10 are known to form nematic mesophases. While BrBA-9 does not show any mesophase by microscopic examination, BrBA-10 exhibits mesophases on cooling; transition to a simple fan-shaped texture (A) followed by a mosaic texture (E). For a comparison purpose, a hybrid compound NCO(CH2)100Br(CBrBA-10) was also prepared. Phase diagrams were constuctured for binary mixtures comprising BrBA-9/CBA-9, BrBA-10/CBA-10 and CBA-10/CBrBA-10. The eutectic temperature and eutectic composition were calculated from the DSC data using the Schoder-van Laar equation. The results were found to be consistent with those observed. For the CBA-10/BrBA-10 system the orientational order parameter of CBA-10 was determined in the nematic state by the H-NMR method. The order parameters of the mesogenic core remain almost identical with those of the pure compound when compared at given reduced temperature T/Tn

Halftonig is a technique to create the appearance of intermideate tone levels by controlling the spatial distribution of the binary pixel values. Recently, many printing devices such as image setter, inkjet printer, laser printer and facsimile, generate image, they require the technique. Ordered dither is achieved comparing the gray scale image to periodic array. This method is fast, but it occurs periodic patterns. Conentional error diffusion generates a good image. But processing speed is very slow and appeares worm artifacts in middle tone scale. To improve it, Bns(Blue noise Screen) is developed based on Gaussian distribution. In this paper, we discribe methods to design BNS based human visual characteristics and to improve blue appearing at edge area of image by USM(using unsharp mask).

Some photopolymer, poly(vinyl cinnamoyl acetate)(PVCiA) was synthesized by esterification of polymer(vinyl alcohol)(PVA) with monochloroacetic acid, followed by reaction poly(vinyl monochloroacetate)(PVAhA) and potassium cinnamate. When esterification of PVA with monochloroacetic acid was reacted in the dimethyl sulfoxide(DMSO), in the synthesis of PVChA, it is very good yield and the successive cinnamoyl acetoxyl esterification of PVCiA can be successfully synthesized. But PVCiA is low photosensitive polymer if net added photosensitizing dyes. Here, we synthesized photosensitizing dyes.

FM screening has been praised for its apparent resolution advantage over conventional AM screening. FM screening is also known for its criticalness of film output and difficulties in the proofing stage because of the microdot formation. However, FM screening is not a well understood process from press performance point of view. This study was carried out for the purposes of introducing the availability of hifi-offset printing to domestic printing industries and evaluating the print qualities between 300lpi AM screen and FM screen with the equivalent sized microdots to 4-5% dot area of the 300lpi AM screen, together with comparing with 175lpi AM screen representing a conventional printing. Solid density, dot gain, color gamut and some other quality properties were measured and discussed.