The halftone method that utilizes their characteristics by combining different halftone algorithm is one of the challenges of producing high quality halftone image. An important factor that influences the combined different halftone algorithm is the contour emerging in the gray level between different halftone areas. This paper proposes a new halftone algorithm to reduce the contour between different halftone frequencies. The authors investigated the contour perception that occurs from image reproduction and found that the contour between different halftone frequencies is hard to perceive when the difference in the frequency spectrum is sufficiency small. A novel halftone algorithm, which modulates halftone frequency gradually according to density level, has been proposed. The proposed halftone algorithm, based on a cluster dot dithering algorithm, generates a fixed minimum dot size. The proposed algorithm obtains a better subjective estimation value.

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An electrophotographic single layer organic photoreceptor consisting of relatively low concentrations of phthalocyanine pigments dispersed in an insulating binder polymer, which is generally referred to as a high gamma photoreceptor, shows the induction effect. The photo-induced and dark discharge characteristics of the high gamma photoreceptors consisting of x-type metal-free phthalocyanine pigment and polyester polymer are well described by our theoretical model which takes into account of the structural trap. We have found that the good charge acceptance and the high gamma characteristics depend on structural traps. It is mathematically simulated that the photoresponse to digital image exposure is not deteriorated in spite of the charge carrier trapping by structural traps during carrier transport.

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The flowability of toner has been evaluated by the vibrating tube method. Twenty-six kinds of test toners were prepared by adding silica particles of 8-100nm in average diameter to the resin particles of 7μm in average diameter under various mixing conditions. In the flowability tests, the frequency of vibration was kept constant; the amplitude of vibration was increased at a constant rate for 100s, and the mass of particles that were discharged from the vibrating tube was automatically measured every 1 s. To evaluate the flow stability of toner, the measurements were repeated 7 times for each test toner. The basic features of the flowability were evaluated by the values of the total mass of toner discharged and the critical vibration acceleration to make the discharge. In addition, using the flowability profiles showing the relationship between mass flow rate and vibration acceleration, the details of the flowability of toner were characterized. A series of experiments showed that the vibrating tube method has the advantage of the short-time repeated tests and can evaluate the variation of the flowability arising from the small difference in the toner preparation conditions.

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We have previously investigated the origin of the unusual high thermal stability of benzyltributylammonium-4-hydroxynaphthalene-1-sulfonate used as a charge control agent(P-51 : Orient Chemical Industries, Ltd.)from the standpoint of the X-ray structure analysis. In anions of P-51, we found chains of OH…O intermolecular hydrogen-bonds between the OH group of one anion and the sulfonate O atom of the neighboring one. The present hydrogen-bond network is found to impart a polymer-like stability to P-51. In the present investigation, we extended our studies to seven derivatives of P-51, in which the cation remains the same while the anion part is modified. Among these, five derivatives are solid and possess various OH…O hydrogen-bond networks in anions : dimer, or one-dimensional, or two-dimensional network. These results lead us to conclude that the hydrogen-bond network is responsible for the high thermal stability of P-51 derivatives. On the other hand, the remaining two derivatives are found to be liquid at room temperature, probably because of the lack of intermolecular hydrogen bonds.

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The electrophotographic full color Printer imagePRESS series has introduced into Print On Demand/Graphic Arts market from 2006 by Canon. “imagePRESS C1+”, released in Nov. 2008, brings new expressions and new use by “new clear toner”. iPR C1+express “flat gloss”, which is like offset printing and partial mat/gloss effect, water mark, Metallic like effect by new clear toner. We'll introduce the clear toner expressions for “Plus One” demand from POD/GA market.

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Paper-handling machines such as printers, copy machines, and automated teller machines are recently finding wide applications in the modern community. Paper-handling machines mainly consist of sheet feeding mechanism, transporting mechanism, and stacking mechanism. In this article, several mechanism and analytical technologies for functions like feeding sheets of paper, sheet transporting, and sheet stacking are introduced. Then, banknote-handling technologies of ATM we developed are introduced.

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Canon released a full-color printing system, imagePRESS C7000VP in 2007 and a black-and-white printing system, imagePRESS 1135 in 2009 for the purpose of moving into a market of POD on a full-scale basis. These are equipped with Air sheet feeding technology for the first time as Canon products. I introduce this technology in detail this time.

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The feature of the POD electrophotographic system is to correspond to “Small lot and Quick turn” and “Variable print”, and the application has been expanded bookbinding business recently. The work flow is optimized by the In-line system that can be automatically consistently processed from the data input to bookbinding by making the printer and the finisher cooperate.
Konicaminolta built the Perfectbinder that the process is generally complex into the In-line system.
This paper explains some techniques of the In-line type On-demand bookbinding system by using “Perfectbinder PB-501” as an example.

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The technology of paper transport in Copier/MFP(Multifunction Printer)has been remarkably improved in recent years, especially on the field of paper jam and skew concerned with the reliability of transporting and utilizing of computer simulation, however, there are several significant problems left in future not only to improve the reliability and cost reduction but also to apply for color printing with high image quality, to reduce the sound noise with paper transporting and to improve between the rising temperature in a machine and the leakage of sound noise and so on.
In this article, finally, it describes the necessity to resolve extra problems for designing and optimizing systematically which are concerned with the rising temperature in machine and the leakage of sound noise except the rules of thumb in the technology of paper transport. In addition, it also describes a couple of case studies utilizing numerical simulation of paper transport.

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We have developed the InkJet printers, GELJET IPSiO GX3000/GX5000. These printers are up to professional standards for business users. And we choose the electrostatic paper feed technique for the means of the paper feed system. The electrostatic paper feed technique for stable distance between the surface of the print-head and the surface of paper to use the long head array for high speed printing and to get the high quality printing.
The electrostatic paper feed technique has two features, mainly. The one is that we can get the static electricity adsorption power to charge with electricity only for the belt, not for the paper. And the other one is that we can get the stable adsorption power, to adjust the width of the charge for the belt depends on the surface resistance of paper.

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