In color reproduction method, there is preferred color reproduction in addition to true color reproduction to the original. The preferred color is said to be related to color from subject's memory, and tends to differ by environmental. We established our original evaluation method of preferred color reproduction by applying “Systematic arrangement method”, a presentation method of test samples which is proposed by Kobayashi in Chiba University. We selected objectives whose memory of color is common to the nations, and devised questioning method easy to identify “the scene” and then established an evaluation method available to global survey. We report the evaluation method of preferred color reproduction and survey results conducted in Japan and the other several countries by using this method.

View full abstract

Distinct Element Method (DEM) is an important numerical technique to analyze the motion of toner particles and carriers in electrophotography. With the DEM calculation, equations of motions for all particles considering the electromagnetic interactions are solved explicitly, and then it spends huge computing time. The parallel algorisms, such as particle decomposition method and spatial decomposition method have been introduced to DEM to overcome this difficulty. However they could not achieve enough parallel performance, especially the parallel efficiency will saturate under many CPUs. In this study, the force decomposition parallel method is engaged, and it realizes high scalable parallel efficiency. It is confirmed that highly accurate results were obtained by large scale development process simulation using force decomposition method.

View full abstract

I have followed the progress of ink jet technology as the parents watch their child grows up with expectation and have contributed somewhat to the progress. With great pleasure, the child, ink jet technology has been evolving even now. The evolution has two directions as extending capability and getting over weak point in the similar way of nurturing. Namely, the former is expansion of ink jet to various applications using simple process and the later means challenges against performance limitation derived from imaging process achieved only by the interaction between ink and media.
The differences of technical approaches in each direction also exist. Progress of elemental technology region has been noticeable in extend of the possibility and challenge against the limitation has been dazzling in system integration or peripheral technology progress.
I would like to present the status of ink jet technology and the prospects in line with two directions of the progress.

View full abstract

We have developed a new aqueous white ink for inkjet printers. For the white pigment, we have used hollow resin particles, an additive known for enhancing the whiteness of paper. Aqueous white ink containing hollow particles are safe for the environment, cause less sedimentation, and produce a more intense whiteness. Aqueous ink has a number of merits. First, it obviates the need for a ventilation duct for organic solvent during manufacturing process. Second, maintenance and printing do not require specific skills. Third, by mixing the ink with colors of subtle shades, it allows control of the hue of the whiteness. The new aqueous white ink will improve workflow of previewing and proofing of the printing materials. In addition, we found that both brightness and opaqueness are important for the whiteness quality of printed images on a clear film.

View full abstract

Two alternative curing mechanisms may be used for UV curable inkjet inks;free radical polymerization and cationic polymerization. Free radical polymerization currently dominates because of its low cost and the ease of design afforded by a wide selection of usable monomers. Cationic polymerization is a new process but has become to get many attracts because of its unique advantages. In this paper technologies and features of the UV curable inkjet inks will be reviewed.

View full abstract

In the current market, textile industry is dominated by China which has the great price competitiveness.
In developed countries, it is increasingly important to meet the market needs, such as better design, originality, short-delivery, small-lot production and high-value-added products.
Digital textile print with the inkjet printer matches such trend.
This writing introduces inkjet printers which are used in the following textile digital prints.
1. High, middle and low speed inkjet printers for textile.
2. Printers which thermally transfer sublimation dye to textile. Sublimation transfer inkjet printer and direct sublimation inkjet printer.
3. Inkjet printer for garment and apparel industry. It can print on sewn products such as T shirts.

View full abstract

In the occasion of applying inkjet technology to industrial field, performance evaluation and verification of developed materials bears important roles. Process of inkjet technologies, required technology components and method of evaluation & verification are explained taking FUJIFILM Dimatix material printer as an example of inkjet printer for research & development. And subjects to be resolved on developed materials and advantage of use inkjet printer for research & development are introduced.

View full abstract

Additive Modeling is new method developed and commercialized in 1980's. It came from totally different concept than traditional subtractive modeling (CNC milling) method, it builds plastic parts by rapidly and precisely adding and curing plastic material layer by layer, and create final parts with the similar quality to injection parts. At present, additive modeling is widely used in rapid prototyping and rapid manufacturing of small quantity of products. Moreover matured Inkjet technology allowed the commercialization of 3D printer, and made it compact, easy-to-use, low-cost, yet, with high resolution and accuracy. This paper will describe the latest 3D printer developed based on Inkjet technology and its application, and its future opportunity.

View full abstract

We are carrying the clustered articles to the title called Imaging Today as a special feature to take up advanced technologies for imaging on the Journal of Imaging Society of Japan. However, in recent years, by the maturity of imaging technologies, the fields of Imaging Today fall into the circulation of the theme. And it becomes difficult to promote an expanse to the technology field of members.
I review of the history of Imaging Today at this time and comment on a trial for the new theme.

View full abstract