The public network is expanding its service from current ISDN to broadband ISDN. In the local area network (LAN) area, a low cost 100 Mb/s LAN is coming. These digitization and high bitrate trends of networks are offering good environments to transferring multimedia information.
The standards and their implementation for compression coding to transfer visual media are in progress Those may be good evidence that the multimedia information age is coming.

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This study examines a new melt-type thermal transfer printing using a focused laser beam as an alternative to conventional thermal-head printing. Our system uses a high-power laser diode as the laser source. We have previously indicated the possibility of high-defintion printing in this method by a number of studies.
In this paper, we investigated the foundamental characteristics of the high definition printing images using the 16-level gray scale of halftone dither and evaluation of 2,032 dpi mono binary printing images, experimentally. As a result, we have confirmed that a favorable tone-reproduction and maximum optical density 1.7 using 8 × 8 dither pattern consist of minimum dot radius 12.5 μm.
Furthemore, we have successfully realized to print high-defintion binary mono images (2048 × 2560 pixels) of 2,032 dpi resolution.

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We studied the influence of the distribution of corona current upon the quality of toner images on the transfer and separation process in electrophotography. The authors have measured the distribution of corona current over a photoconductor drum, and calculated changes in the electric field in the air gap layer between the drum and paper.
As a result we could clarify the following properties of the image quality on this process:
I) The image quality is influenced by the corona current of the transfer corona unit itself as well as that of the separation corona unit.
II) The highest reliability of paper separation and the highest quality of toner images cannot be simultaneously realized as far as the transfer and separation process uses a corona charging system. That is because the corona current when paper separation is most easily accomplished is different from that when the quality of toner images are best.
Therefore we conducted an experiment with an Al laser beam printer in order to inspect these properties and obtain generally good results.

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Several studies have been done for a new analytical method of dynamic ink penetration process, using electrochemical approaches for ink jet printing PET film with unique ink absorption layer. Accordingly we investigated the electrode reaction with three-electrode cell method for this application. The absorption layer was specially organized on the working electrode, and the parallel counter & reference electrodes were arranged oppositely on top of it. An ink drop was applied, and the variation of current through electrodes were simultaneously measured by potential-step chronoamperometry (PSCA) of potentiostatic electrolysis. The penetration of ink into the absorption layer caused changes in the current waveform through the working electrode which could be observed in real time. The ink penetration depth can be specified as the current variation of working electrode. This report outlines the basic properties behind this electro-chemical approaches and the dynamic analysis of ink penetration process.

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Small size toners have been using for the fine image in electrophotographic system. Small size toners were prepared as specimens by pulverize and suspension polymerization method. Shape of the pulverized toner is irregular and it of the suspension polymerized toner is spherical. Characteristics of powder and electrophotography of the both model toners that have almost the same composition but the different shape and mean particle size, were studied. The triboelectric charge of the polymerized toner was able to be controlled by the adding amount of charge control agent same as pulverized toner. The spherical polymerized toner had better flow ability but was not appropriate to the blade cleaning system because of its shape. As the double component developer, the spherical toner had long life due to the less spent toner on the carrier surface.

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