This paper describes a novel technology with which the images of objects with no copyright protection can contain invisible digital watermarking, using spatially modulated illumination. This technology enables the photographed image of non-electrical objects such as classical pictures in museums to contain digital watermarking, without any physical modifications to the objects themselves. We conducted experiments where one-bit binary data were embedded in one block that consisted of 8×8 pixels using the phase of the highest frequency component generated by DCT. The experimental results revealed that embedded data could be read out with almost 100% accuracy. This amply demonstrates the feasibility of the technology described in this paper.
To control toner cloud by a pair of aperture electrode adequately is important in TCB(Toner Cloud Beam), which is a novel printing technology with characteristics of simple mechanism. Experimental toner control mechanism using 4 electrodes of upper electrode, a pair of aperture electrode and lower electrode is composed, and voltages are applied to each electrode. Two modes of toner passing through aperture electrode are observed;one mode is when the electric field between aperture electrodes is same direction as outside electric field around the aperture electrodes, other mode is when the direction is reversed above certain value. Dot formation by pulsed control of toner passing condition is carried out.
Recently, IH fusing technology is paid to attention as an eco-friendly technology of the electro photographic device. IH fusing system has a lot of feature. For example, the energy efficiency of this system is higher than conventional method and this system becomes possible to change the electric power. As a result, the effect of shortening the warm-up time can be expected. We released a product installed with IH fusing unit for the first time in the world in 2000. Afterwards, various applied devices have been commercialized by each company. We can classify IH into the following two technologies as development and transition of IH fusing technology. (1) Technology to improve heating efficiency : Optimum construction and placement of IH coil, Specification of material(roller, belt)to be heated, Development of an inverter circuit (2) Technology to achieve high-quality image (Technology to keep an uniform temperature distribution) : Combination of coils and heated materials with various characteristics, and the system to control them, We expect a further energy saving to use IH fusing technology based on the above-mentioned technology in the future. The details are described as follows.
QSU technology by the heat roller fusing that is the energy-saving technology of the fusing system of Ricoh passes through HYBRID QSU technology by the fusion with the capacitor technology and develops to the color QSU technology that it introduced IH heating into a thermal belt fusing for colors. This report introduces the constitution and the details about this QSU technology.
On-demand Fusing technology has been developed for more than twenty years. At the beginning, it was applied for low speed monochrome printer. But it has been improved to be applied for high speed printer and color printer. And we acquired a lot of knowledge which was quite different from roller fusing. In this paper, we briefly review its history, then explain its unique configuration and control system.
We have developed new color-fusing system “Free Belt Nip Fuser (FBNF)”. This fuser uses small heat capacity fuser roll, thin belt and stationary pressure pad in it. Pressure pad forms wide nip. This fuser has many advantages of short warm up time, energy-saving, low cost and small size. FBNF has made great progress during the last nine years and has been introduced into many Fuji Xerox MFP and printers. We are going to develop it further and expand the area of the application.
Super-high speed continuous feed B/W laser printer, IBM 3800, was firstly appeared in 1975, and then Siemens, Hitachi, etc. entered into market. In 1977, H8196-P10 of Hitachi, Ltd. was launched1,2). Its print speed was approximately 432mm/s (17ips) at the time. And performances described in this report, correcting continuous papers meandering and sufficient fusing energy supply, had not been achieved yet. Then Super-high speed continuous feed B/W laser printers have been used for printing a large number of documents, accounts or statements, in public and common offices. Generally, these jobs must be done in a short period. Then they are taken into account both productivity and peak performance, namely they are required for very high speed, durability and reliability3). In recent years, users of monochrome printers have increased in direct mail or and book markets. Therefore it is necessary to improve performances for handling continuous paper and print quality. In this report, an overview of Super-high speed continuous feed B/W laser printers is described. Especially features of the fusing system, performances of correcting continuous papers meandering and sufficient fusing energy supply in a short time are introduced4). Main features are below. (1)Performance of preheating system (2)Performance for keeping productivity at fuser unit (3)Performance of Backward Wrap-nip Fuser (4)Performance for correcting continuous papers meandering