“Technical Committee on Electronic Paper” of the Imaging Society of Japan (ISJ) set a theme to “think about an image in the future of the electronic paper” from about 2000 and announced the discussion of the application scenario of the electronic paper every three years. In 2011, we returned to the origin that started a discussion of the electronic paper application ten years ago and analyzed a product put to practical use, a display technology and a market trend, and reported the new application scenes of the electronic paper expected in next ten years.
We took up “the second generation electronic paper” as the agenda from 2012, and discussed about a picture of the future electronic paper from various viewing points, such as “a social background”, “a product trend” and “future keywords”. This paper reports “the second generation electronic paper” suggested based on the discussion of the technical committee.
Quantitative measurements of ultrasonic velocity is tried from an ultrasonic image data obtained by the strobe photo-elastic method incorporating the sensitive tint method. Lamb wave lunched in the glass around 2 MHz is imaged by the strobe photo elastic method introducing sensitive tint method. Ultrasonic wave field image that were processed with integration, subtraction and normalization was obtained to develop the contrast of image. In the sensitive tint image, the sound pressure polarity of the Lamb wave are indicated by red and blue, respectively. Using RGB data of S1 and A1 images, phase velocity versus frequency is analyzed to the wavenumber by the FFT to obtain the ultrasonic Lamb wave velocity. The agreement between the experiment and the analysis result revealed that this method can quantitatively measure the ultrasonic Lamb wave velocity.
Propagation of ultrasonic Lamb waves in the glass having gently tapered part is visualized by the strobe photoelastic system introducing sensitive tint method. The time transition of ultrasonic pressure of 1.447MHz burst sine wave propagation are observed. To enhance the contrast of ultrasonic Lamb wave, subtracted image with the C-MOS camera is adopted. As the results, polarities of ultrasound pressure are clearly visualized. As the Lamb wave propagate, higher mode of S2 mode of Lamb waves in the thick part are appeared and they are gradually varied to S0 mode in the thin part via the tapered part of S1 mode.
To improve the efficiency of trademark examination, there is a demand for a system that searches trademarks with similar appearance. We have made such a system focusing on trademark shapes. However, appearance similarity is judged not only by similarity of graphical shapes, but also by conceptual elements of graphics. So, it is necessary to take them into account.
For this purpose, we focus on the Vienna classification. The matching of the Vienna classification indicates that trademarks share conceptual elements. One trademark can have several conceptual elements of Vienna classification, which are independent. Thus, it is possible to consider that similarity is higher if the number of shared conceptual elements is larger. By incorporating the number of shared conceptual elements into the above system, we have succeeded to improve the accuracy by 2%.
Here, we report on the enhancement of field-effect mobility in solution-processed top-gate organic field-effect transistors (OFETs) based on 2,7-dioctylbenzothieno[3,2-b]benzothiophene (C8-BTBT) using solution-processed molybdenum trioxide (MoO3) layers. An aqueous solution of MoO3 was deposited by the spin-coating technique on Au source-drain electrodes fabricated on the Si/SiO2 substrates to form an hole injection layer for the C8-BTBT semiconductor layer. It is found that by exposing MoO3-coated Au electrodes to ultraviolet/ozone (UV/O3) the field-effect mobility of top-gate C8-BTBT FETs significantly increases and the channel-width normalized contact resistance is remarkably reduced to 0.4kΩcm. Top-gate C8-BTBT FET devices with a channel length of 5μm exhibit high effective mobilities up to 1.4cm2V-1s-1. The obtained results indicate that hole doping to C8-BTBT layers by UV/O3-treated MoO3 contributes strongly to the reduction in the access resistance of top-gate C8-BTBT FETs.
Invisible Ag-grid transparent electrodes with a variety of spacing between the Ag-grid lines of 100, 150, 200, 300, 500 and 1000 μm at a constant line width of the Ag-grid of 5 μm and a constant thickness of the Ag-grid of 0.6 μm have been prepared by a conventional gravure offset printing using our newly developed Ag nanoparticle ink. Moreover, the Ag-grid electrodes have been laminated with a poly (3,4-ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT : PSS) layer. In the Ag-grid laminated with PEDOT : PSS electrodes, the transmittance is up to 96% in the visible light region and the sheet resistance is down to 4Ω/□. The repeated bending cycle tests of the transparent electrodes have been carried out. The results show that laminating with PEDOT : PSS enhance the bending durability of the transparent electrodes. The Ag-grid laminated with PEDOT : PSS electrodes would have potential applications as flexible and transparent conductive films in optoelectronics and photovoltaics.
For feature articles of Imaging Today in this issue, ‘The latest photoreceptor technology for electrophotography', this article describes the basic knowledge about the imaging process for electrophotography based on the Carlson process, structures and materials for photoreceptors, and charge carrier transport in photoreceptors, for better understanding of the feature articles.
Recently the negative-charging-type multi-layered organic photoreceptor makes up most of the photoreceptor which is an important device of an electrophotography process. On the other hand, two kinds of positive-charging-type photoreceptor have been used by KYOCERA Document solutions. One is a positive-charging-type single-layer organic photoreceptor, and the other is an amorphous silicon photoreceptor. The former is used by our machine model widely from a low-end printer to A3 MFP (Multifunctional Products) due to environment, high-resolution and low-cost. Because each process of carrier generation, carrier injection and carrier transport are proceed at the same time in the photoreceptor, the photo-induced decay phenomena undergoes influence of the several interactions between the constituent materials, the inner electric field distribution by a space charge and recombination. Therefore it is necessary for photoreceptor development to consider these interactions. In this report, history, operation principle and technological issue of positive-charging-type photoreceptor are outlined.
Organic photoconductor (OPC) has been steadily improving in printing speed and product life since launched in the 1980s. Today, OPC is used without replacement in some office machines. In the case of the industrial printing, it is necessary to minimize the machine maintenance time caused by OPC damage for cost saving. Therefore, it is strongly required from the market that OPC has high durability and long product life time. The function of OPC has developed as an electronic device that requires various functional characteristics such as sensitivity, speed responsiveness, mechanical strength, surface physical properties, and so on. The environment in which OPC is used is not so good compared with other electronic devices. Therefore, it is impossible to drastically prolong the life of OPC by simply improving electrical performance. Konica Minolta collected and sorted the customer environment and failure information worldwide. We have developed technologies for occurring and predicted faults and applied them to products.
Fuji Xerox began full-fledged launch of its own developed organic photoreceptor in the 1990' s, and replaced it with an organic photoreceptor from the selenium inorganic photoreceptor used until then. Since then, in response to the demand for long life of office multifunction printers and printing markets, we have been prolonging the life of photoreceptors, which is the rate-limiting factor of life.
Improvement of undercoat layer with respect to internal factors such as material deterioration, improvement of stress tolerance of the surface layer (charge transport layer/overcoat layer) and improvement of friction coefficient (charge transport layer/overcoat layer) against external factors such as wear/scratch, etc. have been carried out continuously. In this paper, we introduce the history of development of photoreceptors up to now, and the technology of the latest undercoat layer, charge transport layer and overcoat layer.
Life improvement of organic photoreceptor has been one of the biggest challenges since it was introduced on the market. For improving service life of organic photoreceptor, development of the high stability of charging performance and reproducibility of the latent images is a major challenge. Ricoh group have intensively developed various technologies for the high-durable, long-life organic photoreceptor, we especially focus on the abrasion resistance technology and the chemical durability technology. In this article, we introduce following two technologies : (1) abrasion resistance technology by various types of over-coat layer, (2) chemical durability technology by acid scavenge donor and charge transport monomer.
TASKalfa 6052ci which launched September 2016 has many new technologies, energy saving, high image quality and high reliability, also it achieved miniaturization with its machine size and weight decrease about 20% from previous model. Especially, we focused that the cause of wear of the cleaning blade edge depends on the shape changes of a-Si drum surface, and we tried to modification of the drum surface. As a result, the wear amount of the cleaning blade edge was reduced to about 25%, also, the cleaning performance for high circularity toner was improved, and it contributed to the low drive torque for the drum unit. In this article, we report the surface modification of a-Si drum that contributed greatly to the reliability of TASKalfa 6052ci.
Characteristics of photoreceptors in electrophotography, dark discharge, photo-induced discharge, and residual voltage, were reviewed on the basis of depletion discharge, emission-limited discharge, and space charge trapped in deep localized states, respectively. The characteristics of the photoreceptors were governed by their transport properties such as photocarrier generation efficiency, drift mobility, deep trapping lifetime, and localized-state distribution. Time-of-flight technique was reviewed for the characterization of the transport properties.
In recent years, data generated worldwide are exponentially increasing due to the spread of businesses, services, etc. utilizing ICT such as cloud service and big data. A Demand for magnetic recording tape is rapidly growing as recording media for long-term storages and archiving services. In order to meet such needs, we noticed the limit of the metal magnetic particles and quickly studied on application of barium ferrite magnetic particles (BaFe) for magnetic recording tape. The characteristics of the BaFe magnetic particles are as follows : 1) the origin of magnetization originates from magneto-crystalline anisotropy, 2) it is not necessary to provide a passivation layer because they are oxides. 3) Therefore it is easy to microparticulate the BaFe particles required for high density recording. Compared to the latest metal magnetic particles, we succeeded in reducing the volume of the magnetic particles to 44% while maintaining their coercivity.
We can anticipate a performance and properties of metallic materials by microstructure's observation and analysis results. And we can control the product performance by microstructure. Therefore specimen production methods were expounded for preparation of microstructural observation and analysis. Microstructure consisted of atoms, so that it was 3 dimension structure. And goods for us have 3 dimension construction similarly. On the other hand, nobody have direct three-dimensionally-observed and/or analyzed methods for metallic materials. Therefore it was required that the three-dimensionally-understanding of microstructure and analysis results from two-dimensional results.