Today's rising demand for paper copy machines require components of even higher reliability, stability and performance.
Heat roller, a component used in the final stage of copying process, directly affects quality and fixing of copied materials. The roller is required to provide a stable performance under severe operating conditions including load and a constant exposure to heat.
Thermal analysis, deterioration test and operative evaluation of paper feed test were conducted by the researchers. A closer correlation was found between life and design and/or degree of material deterioration of the roller. Accelerated life test was used to est imate life of the roller within the laboratory.

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The carrier transport properties in multilayer photoreceptors of As_xSe_100-x/Se have been investigated by the time-of-flight method. The time dependence of the photocurrent is characterized by an initial decrease, a subsequent increase and a final fall in current. Such currents are observed for the electron transport in the case x = 3-15, and for the hole transport in the case x=15-40 atomic %. The time when the current shows the maximum value after a flash-light exposure is found to be dominantly affected by the spread of carrier packet passing through the first layer (As_xSe_100-x), unlike a previously reported Se₉₆Te₄/Se photoreceptor. The time dependence observed for the electron transport (x = 3-15) is roughly explained by assuming the gaussian distribution of carriers drifting in the first layer. On the other hand, the photocurrent due to the hole transport (x = 15-40) may be interpreted in terms of the nongaussian distribution (dispersive transport model). Furthermore, multilayer photoreceptors may serve for determining the transit time of carriers in a photoconductive layer exhibiting only a featureless decay if it alone is examined for this aim.

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In order to clarify the development mechanism of insulating magnetic toners, we devised an experimental method, to be referred to as “Potential Decay” method, where one measures how a D. C. potential of an aluminum drum, initially given through connecting a charged capacitor, will decay via toner particle motion caused by the developer roll revolution.
The experiment was made on several kinds of toners, including 4 commercial ones, and following results were obtained;
(1) Without toner particle motion, very little potential decay was observed.
(2) Irrespective of insulating property of the drum surface, the effect of supplying fresh toner particles by the toner layer movement has major contribution to the potential decay.
(3) Even when the developer roll surface was insulated, only minor changes in the decay characteristics were observed for the measured two sampples. The following were inferred from the above results ;
(1) Charge injection from the developer roll to the toner particles has a minor contribution to the toner charge necessary to the developing process.
(2) At least for those two samples, main part of the toner charge is due to mutual friction among the particles.
(3) The charge enhancement model proposed by Nelson is not to be completely discarded.

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Photosensitization of poly-N-vinylcarbazole (PVK) was investigated using three different structured intramolecular charge transfer (CT) complexes consisting of carbazole donor chromophore and tricyanovinyl accepting group as a sensitizer. These compounds show considerably high sensitization in their respective intramolecular CT absorption bands. From the analyses of the induced photocurrents in pulse photoconduction measurements, the initial separation and quantum yield of ion pairs were estimated based on the Onsager model. Compared with intermolecular CT complex sensitization in PVK-TNF (2, 4, 7-trinitrofluorenone) and PVK-TCNE (tetracyanoethylene) systems, the higher quantum yield but smaller initial separation (r₀=22 Å) of ion pairs was obtained independently of the structure in the present intramolecular CT complexes.

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Reciprocity failure data of electrophotographic photoreceptor are important characteristics in the design of practical Laser beam printer.
The Reciprocity law in four kinds of photoreceptors, that is α-Se layer, PVK-TNF layer, Copper-phthalocyanine binder layer and dyed-ZnO binder layer, have been measured by using Ar-Laser and He-Ne Laser. In constant total exposure, exposure time was changed in the range of 10^-2 to 10^-6 sec and light intersity was changed in the range of 10³ to 10⁷ erg/cm². The Reciprocity law in each photoreceptor is held in exposure time range of 10^-2 to 10^-5 sec and not held in exposure time over 10^-6 sec.
The amount of failure depends on the wavelength of light, which is related to spectral absorption of photoreceptors. Most largest decrease of electrostatic sensitivity in the case of α-Se at exposure time over 10^-6 sec is about 10% of normal sensitivity. But the failure may be not observed in the image density formed by toner development, because the electrostatic contrast of latent images for the development is enoughly held in about 10% decrease of the electrostatic sensitivity by reciprocity failure.

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