The material perception is a perceptual phenomenon that our brain feels from retinal images. Now, the analysis is progressing which feature of the optical image is effective as a stimulus for the cerebral visual cortex. Since the complex factors are involved in material perception, it's hard to describe in a clear mathematical model. Hence, there is a tendency to rely on any intuitive and/or heuristic methods for emphasizing and reproducing the material appearances.

This paper introduces a novel approach for enhancing and reproducing the material appearance without any measuring tools such as BRDF. The trials with the following two key ways are reported.

A : Enhancements on air clarity, gloss, and textural feelings B : Reproduction on preferred material appearances by color transfer between scenes. The air clarity or gloss sensation are enhanced by a Dehazing and the visual textures are improved by a Weber's contrast model and their cooperative effects are contemplated. Our brain perceives an object in the visual cortex. In the visual cortex, the color distributions are highly concentrated in the central Fovea and roughly scattered in the peripheral. Taking this spatially-variant color concentration property on central vision into account, the material appearance is transferred from one scene to another by just matching the principal component with that of target scene. Just illustrating an example scene with a target texture, a source scene is automatically converted to that with preferred material appearance.

Transfer characteristics and complex impedance spectra of organic field effect transistors (OFETs) using poly (3-hexylthiophene-2, 5-diyl) (P3HT) have been measured before and after exposure to laboratory atmosphere. Although the transfer characteristics were not changed after the exposure to laboratory atmosphere, a new structure was found in the complex modulus spectra below 10 Hz, calculated from the complex impedance spectra. Since it is likely that the structure is due to interface state created by atmospheric exposure, an equivalent circuit of OFET considering the interface state was proposed. The complex modulus was derived from the equivalent circuit and was in good agreement with the experimental results. It has been demonstrated that information concerning the interface states as well as the field-effect mobility, the resistivity of the gate dielectrics, and the contact resistance was obtained by means of impedance spectroscopy measurement of OFETs.

Piezo-ceramic transducers are often used to generate ultrasonic waves. In many cases, the transducer is driven in the thickness direction. However, its thickness vibration velocity is not always uniform over the acoustic radiation surface of transducer. This is because the elastic coupling in the longitudinal direction and the lateral vibration are existed even when transducer is driven in the thickness direction. To suppress the lateral component of vibration, “siding” method to load the side of the transducer is newly proposed. In order to verify the effect of siding, vibration velocity of the surface of disk-type transducer is measured. Furthermore, the sound field in the water is observed by the Schlieren method to show that there is no unnecessary radiation, and the advantages of siding are clarified.

The authors have demonstrated that the coating films of perchlorate-doped 3-methoxythiophene oligomer exhibited a gold-like luster. In this study, the use of tetrafluoroborate as an alternative to perchlorate provided films with different color and optical properties. Perchlorate-doped film showed a yellowish gold-like luster. On the other hand, tetrafluoroborate-doped film exhibited a gold-like luster closer to white by the addition of greenish luster, and its specular reflectance was higher than the perchlorate-doped film. Gel permeation chromatography and energy-dispersive analysis of X-rays revealed that molecular weight and doping level for the two films were almost the same. X-ray diffraction measurements demonstrated that the quantity of edge-on lamellar crystallites, which are considered as the structural factor of the gold-like luster, in the tetrafluoroborate-doped film were larger than that in the perchlorate-doped film. Based on these findings, it was suggested that the difference in color and specular reflectance of the two films were caused by the difference in the ability to form the edge-on lamellar crystallites between the tetrafluoroborate and perchlorate ions.

During the cleaning process of electro-photography, there are some problems that a toner or an external additive adheres on photo receptor or slips and an abnormal image is generated. In the view from above, techniques for applying a lubricant on the photo receptor are known. There was a scene that it was difficult to confirm the correspondence with the problem at the design development because the analysis technology to the quantitative index of the application condition of the lubricant was insufficient. This report will introduce that a quantitative analysis method of lubricant application condition is established using some analyzers, and an example applied to actual design development problems.

Downstream discharges are generated by some combinations of a charging roller and OPC (Organic Photoconductor) drum in the charging process of electrophotography. Although downstream discharges make a significant impact upon image quality, the quantitative measurement is very difficult because they are extremely weak and generated in narrow area. We measured the current profile in charging process by using the special OPC drum. This special OPC drum have micro patterning electrodes which were fabricated under the OPC layer. The current profile is composed of discharge current and virtual displacement current. We could extract the discharge current and detect downstream discharges. Computed results of the discharge and virtual displacement current show good agreement with experimental results.

Canon has developed the ODF (On Demand Fuser) for saving energy consumption, shorter first print out time and smaller size.

The wear loss of fixing film is important factor to determine a product life of the ODF. The top layer wear on fixing film is evaluated by durability test that requires huge man-hours because it cannot be predicted by common way. In addition, it is thought that micro-slip occurs in the nip of fuser unit. This study clarifies the mechanism of the top layer wear caused by micro-slip and describes the method of predicting wear loss by FEM (Finite Element Method).

One of the problems about image quality of the image after fusing is “a density unevenness”. The density unevenness is a phenomenon in which dark and light regions are randomly distributed in the solid image. The physical model of the density unevenness was vague, and its quantitative evaluation method have not been established, so that a logical explanation for the quality could not be provided. Therefore, we tried to construct a physical model and a quantitative evaluation method. As a result, correlation with image evaluation was confirmed by setting the physical model to “Ratio of diffused light due to the surface shape of the toner layer in dark and light areas” and the quantitative evaluation value to “Diffusion light ratio”. This paper reports the outline of the evaluation method, the results of correlation verification with image samples and a reason of improvement by applying an elastic layer to the fusing film.

While digital communication is accelerating in recent years, a shift to a digital printing machine is accelerated from an offset in print market. Fuji Xerox developed white toner for “Iridesse^TM Production Press ” which is higher model of “Color 1000i Press”. The ideal structure of white toner is that the white pigment is added in high concentration, uniformly dispersed internally and there is no pigment exposure to the surface. We examined a thin and uniform shell structure of toner. And, we applied Super EA-Eco low melt technologies to white toner. As a result, we have succeeded in developing white toner that is capable of the low temperature fixability, high whiteness/opacity and high transfer property.

When printing on paper with a conventional water-based inkjet printer, there was a problem that wavy wrinkles (cockling) occurred on the paper and the print quality degraded. This is because the image area and the non-image area are stretched unevenly as the paper absorbs the ink. Cockling occurred especially when high-density images were printed or when thin paper was used, and it was difficult to prevent this with conventional technology. In order to solve this problem, we have developed a unique drying technology that repeatedly nips paper to multiple heating rollers and extends the drying distance. RICOH Pro VC70000, a high-speed full-color inkjet printing system for continuous paper equipped with this technology, suppresses cockling even when high-density images are printed or when thin paper is used. Furthermore, it has become possible to improve printing speed and image quality with space and energy saving.

In 2018, Ricoh released the “RICOH Pro T7210” large format flatbed IJ printer for industrial printing. The RICOH Pro T7210 achieves high productivity of up to 100m²/h by arranging 12 IJ heads in a 6-row zigzag pattern. The RICOH Pro T7210 can select ink from three types of ink sets : “T7210”, “GP120”, and “DG130”. Above all, “DG130” is positioned as a high-performance ink and has the characteristics of “high production”, “high adhesion” and “wide gamut”. The DG130 has both high adhesion without primer ink and wide gamut that can be applied to the sign and graphics field, such as acrylic substrates that are in demand for flatbed IJ printers.

In this paper, we report on the functions of the ink to realize high adhesion and wide gamut, which we found in developing DG130.

Numerical simulation model of free surface, with the consideration of water evaporation and viscosity change, is proposed to investigate droplet deposition phenomena of inkjet. The model includes moisture convection-diffusion analysis, and estimation of viscosity-change due to the evaporation. The behavior of droplet deposition on printing media is simulated, and the thickening on the surface of the droplet is reproduced. Behaviors of a sessile droplet are simulated with the consideration of evaporation and viscosity change, and the calculations show good agreement with the experimental observations. However, the simulation needs a lot of assumptions and parameter adjustments, and the consideration has made clear the problems of the model.

Numerical simulation with the consideration of the relationship between dynamic contact angle and contact line velocity is carried out. The imaging quality of ink jet printings is affected by droplet behavior on the media, and a prediction of droplet behavior on the media with a numerical simulation is desired. In these days, the droplet behavior has been studied by many researchers. Consideration of the relationship between dynamic contact angle and contact line velocity as boundary condition is popular for a droplet deposition simulation. However, most of the simulations are carried out with a large (mm order) droplet, which consists of simple materials (water etc.). In this study, we simulate the behaviors of a small (μm order) ink droplet with the consideration of the relationship. The simulation shows a good agreement with the experiments for various kinds of the media.

In last article, it was reported that in serial scanning inkjet printers, a very strong correlation was found between the graininess degradation due to misalignment between the reciprocating scans and the graininess of dot patterns formed by either forward or backward scanning. It was shown that by developing a new halftone method that improved the latter, it was possible to realize a halftone with improved robustness that greatly reduced the deterioration of graininess when misalignment occurred. As a follow-up report, this report conducts a more detailed analysis of the graininess degradation mechanism during misalignment between reciprocating scans, such as frequency characteristics. Clarified that the medium and low frequency components hidden in the dot pattern formed by either forward or backward scanning are revealed by misalignment, which is the cause of graininess degradation.

In recent years, the development of electronic devices using printing processes has attracted much attention. In particular, inkjet printing is one of the most useful methods for device fabrication because it has many advantages of digital on demand, scalable, and non-contact. However, in inkjet printing, there is a problem that it is difficult to form fine patterns of 10μm or less due to the wetting and spreading of landing droplets. In this report, to solve this problem, we report a fine electrode patterning method that combines the wettability pattern on the substrate surface and inkjet printing. By using this method, we have successfully fabricated the fine electrodes of 10μm or less with small variation. In the short channel organic thin film transistor (TFT) fabricated using this method, a good field effect mobility of 0.23cm²/Vs was obtained.

Organic thin-film transistor (OTFT) devices have attributes that are difficult to achieve with conventional silicon (Si) based thin-film transistor technology, such as thinness, flexibility, and lightweight. Moreover, OTFT devices can be produced printing methods using inks created using silver nanoparticles, organic semiconductors, or dielectric materials, and their characteristics are improving year by year. Integrated circuits using only p-type semiconductors have been well studied, since p-type semiconductors generally have higher performance vs. n-type semiconductors, such as enhanced mobility and atmospheric stability. However, the performance of n-type semiconductors has recently improved, and there has been an increasing number of reports on research activity relating to complementary integrated circuits employing both p-type and n-type semiconductors. In this study, we have developed a fabrication process for complementary integrated circuits using printing methods, realized using a p-type semiconductor layers that do not require electrode surface modification.

Energy saving is an important issue in the imaging equipment industry for printers and multifunction devices, and energy saving standards are getting stringent year by year. Currently, there are various energy saving standards in each country, but standard requirements for total power consumption are becoming mainstream. The US ENERGY STAR^® is the global standard for total power consumption. Acquisition of ENERGY STAR^® has become a requirement for public procurement in each country, and manufacturers have continued to innovate to meet this standard. The standard of ENERGY STAR^®, which has been promoting energy conservation in this industry, was revised last year, so this paper will explain the trends of each energy conservation standard focusing on the revision of this standard.

In recent years, energy-saving technologies for electronic copiers have evolved with the revision of ENERGY STAR^® and Blue Angel Mark. However, in the area of 65 to 75cpm color high-speed machines for offices, as a result of the trade-off with maintaining the performance, the energy-saving technology cultivated with low and medium speed machines cannot be transplanted as it is, and technological innovation for improving the TEC (Typical Electricity Consumption) value is not progressing compared with low and medium speed machines. In e-STUDIO7516AC series which is a TOSHIBA TEC's high-speed machine for office use, an IH (Induction Heating) fuser meeting the specifications for high-speed machines was developed based on the IH fuser used in medium-speed machines, and the industry-leading top TEC value was achieved (as of October 2019). This article describes recent development trends in fusing technology, and IH fusing technology introduced in the e-STUDIO7516AC series.

Recently, environmental consideration is required in various business field, in the context of global energy and environmental issues. In the field of our multi function printer (MFP) business as well, efforts for improving energy efficiency is increasingly demanded. The low temperature fixability of toner is focused in terms of energy-conservation of MFP. Chemical method toner has superiority in low temperature fixability, since it is highly flexible in controlling size, shape, structure and amount of internal additives such as wax. However, it also has some disadvantages that it requires large scale of facility investment and washing process which needs tremendous amount of water for removing surfactant. On the other hand, pulverized method toner has advantages such as minimized facility investment and fine dispersion of internal additives by melt-kneading in binder resin in the state of high viscosity, while it has disadvantages in controlling structure and handling low-melting-point materials, and therefore, it has a difficulty in satisfying both low temperature fixability and storage stability at a high level. Recently, however, some pulverized toner, which has overcome those specific issues and achieved comparable performance of low temperature fixability to that of chemical toners, has brought to market. In this paper, we report on our approach for energy saving with our pulverized toner technology.

In recent years, the effective use of limited resources has become a major issue in the future due to the rapid increase in energy consumption against the background of global warming due to rapid industrialization and economic growth.

Fuji Xerox has developed EA-Eco (EA : Emulsion Aggregate) toner with excellent energy-saving performance and contributed to energy saving of Fuji Xerox printers. We have developed Super EA-Eco toner, which has further improved the low-temperature fusing performance of EA-Eco toner, and has adopted it for Fuji Xerox printers, multifunction printers, and production printers.

Super EA-Eco toner uses newly-developed sharp melting polyester in the toner by Fuji Xerox's original emulsion aggregation method, achieving ideal viscoelastic properties and low-temperature fusing performance. Super EA-Eco toner also has the characteristics that the particle size is the smallest in the industry in addition to low-temperature fusing performance, so it not only contributes to energy saving, but also high image quality, high productivity, and high added value. Normally, low-temperature fixing design and particle size reduction design deteriorates fluidity, but Super EA-Eco toner has functional fine particles around the toner in addition to toner viscoelasticity design. By reexamining the balance between the type and size, the problem of fluidity deterioration is solved.

Konica Minolta launched “bizhub i SERIES”, the new generation MFPs (Multi Function Printer) and printers in 2019. In this paper, newly developed technologies on this series for reducing environmental impact were introduced. Stand-by power consumption was reduced by various means such as employing low power devices including LPDDR4 (Low Power Double Data Rate 4), improving power efficiency by DC-DC converter, and finely tuning in a process of the energizing block. Waiting time from the stand-by mode was reduced by reprograming its controlling sequences from 4.8 seconds in “bizhub C368” to 1.2 seconds achieving both operability and energy-saving. The new toner realized 10°C reduction of its fusing temperature compared with the conventional toner and sufficient heat resistant storage property by introducing a new resin and realizing a thin shell structure. Fusing unit achieved-38% reduction of its thermal capacity by employing a pad pressure method and downsizing fusing belt and roller as well as improving their heat insulation. Those items enabled to fulfill the International ENERGY STAR Program ver. 3.0 taking effect in October, 2019.