The wax-based electrophoretic rewritable media has been studied due to the expectation of good preservation property. In the previously proposed methods, external heating mechanism is required to melt the wax-based media. In this proposed method, joule heating by current flow at the lower electrode is used to melt the wax as an alternative heating method. It is confirmed that rewritability is possible by this method. Thermal characteristics of this proposed display is discussed.
The issues with high-speed inkjet printer are important for personal and industrial printing. A large-sized print head with a greater number of fine nozzles for ejecting ink could conceivably be used as an effective measure. A print head is configured from stacks of plates which have accurate figures. When such a structure is applied for a large-sized head, the difference between the expansion coefficients of the nozzle plate and that of the cavity plate causes the deformation of the nozzle plate, which is thinner than the cavity plate with the process of time. We assume the deformation greatly influences the direction in which ink ejected from the nozzles travels, so that the direction of ejected ink droplets can be unstable and the print quality can deteriorate. To reduce the risk of the nozzle plate deformation, we produced the head using nickel for the cavity plate united with the nozzle plate instead of conventional silicon and evaluated the basic capabilities. The nozzle plate deformation was decreased by replacing the material of the cavity plate with nickel. However certain parts of some samples printed by the head showed the size variation of ink droplets that was visible to the naked eye. We thought the size variation of ink droplets was caused by ink droplets having a large weight variation that was generated during ink ejection, and the variation of ink weights has a correlation with the large difference among the depths of the pressure chambers and the thinness of the nickel cavity plate. We measured about the depths of the pressure chambers and the address, ink weights and the thickness in the experiments. To solve the size variation of ink droplets, we improved the variation of the depths of the pressure chambers and the thickness of the nickel cavity plate by developing the process method. As the result, the size variation of ink droplets reached a level that could not be detected by the naked eye. We clarified that the main cause was the depths of the pressure chambers and the variation of ink weights.
It is from the second half of the 1970s that applied the technology of the thermal-transfer-printing system to the world, and it was put in practical use as the printer and word processor of a season ticket issuing machine. Especially in the word processor, electronic equipment manufacturers came to sell many word processors to the market. However, when it becomes late in the 1980s, a personal computer will replace a word processor by evolution of software, and it came to be classified and used for the personal computer and the printer (terminal printer). At the present, this terminal printer becomes not only a thermal-transfer-printing system but a form which competes and suits high-definition picture formation from convenience or cost, and the number of the printers of an ink-jet system or a laser print system is increasing. However, since a work principle is easy in a thermal-transfer-recording system and also there is a feature that the design with budget prices is comparatively possible, and it can miniaturize, many are used also for fields other than a terminal printer. There are specifically two, a melting type thermal-transfer-printing system and a sublimated type thermal-transfer-printing system, in a thermal-transfer-printing system. One is since fine printing performance and the durability of printed matter are good, it is used for many fields, such as a facsimile and a bar code, another is used for the photograph field which forms a picture because it can express story tonality richly in the latter. Development of ink ribbon with functionality is needed to change of such a market, and the performance as a thermal-transfer-printing material has also come to improve by improving development of ink and coating technology. Especially this article explains focusing on a change of the ink technology of a facsimile or the melting type thermal-transfer-printing material for bar codes.
Toner and developer had been studied to meet the various requirements such as digitization, colorization and environment-friendly machine. The evolution of various toner and developer according to the progress of xerography technology will be described in this paper.
In the electrophotographic process, the photoreceptor is most important devise in image forming unit. The photoreceptor has the structure that the photoconductive insulating film was installed in the conductive substrate, and it can form the electrostatic latent image on it by the photoconductivity. Although the material utilized for the photoreceptor was the inorganic material in the invention initial stage, organic materials were used in the present stage, because that organic materials were useful in view of easy molecular design for desired function. In this report, development of materials in photoreceptor was outlined mainly on the function of the photoreceptor.
A brief history of the recording media for electrophotography is outlined. Xerox 914 was launched at home in 1962. Around the same time, development of the recording media was started. In '84 acid paper was changed over to alkaline paper to improve the preservation of documents. The color copying machines and printers were marketed from the second half of the '80s. The paper properties, e.g., image quality, sheet-feeding stability, etc. have been improved. The color POD printing machine was come to the market in the '90s. A color PPC sheet to correspond to duplex printing was developed. And then POD coated paper without blister caused by the fusing heat was developed. The POD printing machine using a liquid toner also appeared at the period. The image quality of LEP moved toward the quality of offset printing. Furthermore, some of recent technologies about the media are also reviewed.
Inkjet ink whose commercial viability started from aqueous ink has increased the kind of materials to use such as solvent ink, solid ink, oil-based ink, UV ink and latex ink. With diversification of ink, we can print on various media other than the paper. By evolution of ink, the applied area of inkjet technology has rapidly extended not only for personal use but also from high-speed POD printer, textile and outdoor sign graphics field to plastic decorating industry etc. In this report, we introduce an outline of historical development of inkjet ink materials and its application. In addition, we describe development subjects of inkjet technology also in the future.
Inkjet is an important technology in photo printing. Matte-coated paper which was developed for early generation dye inks continues to be used to the present day as the most convenient media without undergoing significant change of main structure, although it has been improved and adjusted for new inks such as pigment inks, photo inks etc. and new digital half toning techniques like error diffusion method. The micro-porous media was developed some time later and became the major media for photo printing. Nowadays the photo quality of it can compare favorably with that of silver halide photography which has been aimed for a long time. However the rival in the imaging viewer has not been silver halide photography anymore and has started to turn to electronic media such as the liquid crystal, although inkjet technologies have changed the environment surrounding photo printing drastically. Many basic technologies of inkjet media that can produce high quality image were created through the development of matte-coated paper.
Organic pigments has been developed in line with development of printing technologies. Reviewing developing history of major organic pigments, which is used for printing, and feature of major pigments, which is used for traditional printing inks, electrophotography and inkjet. Then, stating the situation of pigment modification and development for the latest electrophotography and inkjet technologies. Nowadays, the mass-environment for organic pigments is becoming severer due to new regulations, rules and guidelines. Therefore, pigment manufactures are dedicating its development and improvement in order to respond to such new market requirements.