The printing method of the thermal transfer printer is to push an ink ribbon that is heated and melted by a thermal head to a printing paper, and transfer the ink to desired positions on the paper. Thus it is important to place the heater of the thermal head at the position where the contact pressure becomes most high. The visco elastic properties of the ink, PET and platen rubber were measured with a rheometer. The contact pressures on the thermal head were calculated by FEM. The contact pressures under consideration of visco elasticity were different from those calculated by elastic analysis. The effect of sliding speed of the thermal head on the contact pressures was also examined. To examine the effect of the contact pressure on the print quality the optical densities were measured with the heater position of the thermal print head changed. The optical densities were changed with the heater position. It can be found that the optical densities decreased with the calculated contact pressure. We designed the thermal print head by using this analytical result, and confirmed the print characteristic.

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We developed new rewritable system which is composed of bacterial-cellulose (BC)/silica composite paper, microbial ink derived from the fermatation of Monascus fungi and fading process using corona discharge. From the experimental results, we note that: (I) the print on BC/silica composite paper exposed to the corona discharge has only a fading time of 10 s (the time is at least 1000 times faster than that of print for the photo-fading), (II) the paper coated with BC/silica layer is more effective in a fading treatment than non-coating paper, (III) the loss of chromophore in monascus dye is attributed to electrophilic reaction by oxidation gas, i.e., ozone, resulting in a low ionization potential of monascus dye, (IV) the rewritable performance is useful for several times. Taking all the factors into consideration, we propose that biotechnology-exploited ink and media together with low-energy discharge process constitute a new-environmental rewritable system, which can encourage reuse and recycling of paper.

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Two kinds of novel single-component black pigments have been presented. The first product is benzimidazo perylene compounds. The black color is achieved by superposition of two absorption bands in the visible region, one of which is due to individual molecules and the other arises from intermolecular interactions between transition dipoles. The present pigment is characterized by deep black-shade, as well as light-and heat-fastness. In addition, it exhibits high electrical resistivity and possesses no IR-absorption. On the other hand, the second black pigment has accidentally been obtained in the course of our investigation on the crystal growth of diketopyrrolepyrroles from solution. This pigment is basically prepared by only 2-methyl-2, 4-pentanediol and nitric acid in an autoclave at about 160°C. The product possesses all necessary pigmentary properties and also exhibits high electrical resistivity. However, details on the molecular structure remain still unclarified.

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We have previously developed a high-sensitive H₂ gas sensor utilizing a high proton affinity of p-dipyridyldiketopyrrolopyrrole (p-DPPP). The sensor exhibits a remarkable reduction of the electrical resisitivity by two orders of magnitude under 0.05% H₂ due to protonation at the para-site of the pyridyl ring. The present outstanding result motivated us to further investigate o- and m-derivatives in order to achieve an even better performance. However, the performance of these isomers was extremely poor. For this reason, the present investigation has been carried out in order to clarify the mechanism of the poor sensitivity from the standpoint of the electron delocalization (i.e. electron conduction) within the molecule as well as the electron hopping from one molecule to another (i.e. structural problem). As for the electron delocalization in p-DPPP, the change in electron density at the para-site(due to e.g. protonation)is found to be well propagated throughout the molecule, while those at the o- and m-sites are ineffective. This explains why p-DPPP is much superior for H₂ gas sensors to o- and m-DPPPs. Another support is also given by the structure analysis of o-, m-, and p-derivatives. The N atom of the pyridyl ring (that serves as the antenna for protonation) remains unbonded (i.e. free) in p-DPPP and is capable of accepting protons. On the other hand, the N atoms are totally blocked by the formation of NH…N hydrogen bonds in o- and m-DPPPs. The above molecular and crystallographic considerations lead us to conclude that p-DPPP is, by far, advantageous to H₂ sensors over o- and m-DPPPs.

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In this paper, the utilization of medical images in clinical settings is reviewed. First, applications of various segmentation and contour extraction methods in clinical settings are introduced. Second, three-dimensional image display methods used in clinical settings are reviewed using some examples. Third, the utilization of a method for motion detection such as optical flow is reviewed, and its clinical usefulness is introduced. Fourth, it is mentioned that with recent development of medical apparatus such as X-ray CT and magnetic resonance imaging (MRI), the generation of functional images related to blood flow and metabolism has become possible and increasingly important. Fifth, the importance of multimodality image fusion in clinical settings is mentioned. Finally, the recent development of computer-aided diagnosis (CAD) is also mentioned.

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This paper describes on the general feature of the radiographic imaging, the latest radiography equipment and the technology, radiographic image quality, image processing and future prospects. The radiographic imaging is different than the ordinary imaging in many aspects. One of the major differences is that the wavelength is extremely short (0.05nm). Conventional film and conventional image intensifier are going to be replaced by the latest digital radiography and fluoroscopy system respectively having a flat-panel detector that can display the image immediately after exposure. The x-ray exposure is so limited to show the wave-particle duality due to the dose consideration that some technical concepts such as the detective quantum efficiency in the evaluation of the image, as well as the sensitivity of the detector are required. The digital radiographic equipment has many kind of image processing such as the sensor characteristics correction and the diagnostic processing, then it makes the system to offer the high diagnostic quality images.

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DICOM was announced as a standard of a medical image 13 years ago. Now, generally DICOM is treated as a standard of a medical image. This paper explains the outline of DICOM plainly.

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The thermal printer is widely utilized for medical reference hard copy system, because of the advantage of small, high quality printing, high speed, high reliability, and low noise. Especially for the diagnostic ultrasound system and the electronic endoscope, monochrome direct thermal printer and the dye sublimation thermal printer are standard. This paper explains the necessary characteristic and performance of the thermal imaging material for the medical reference hard copy system.

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In recent days, digitalizing of the imaging for medical diagnosis is rapidly spread along with progress of image diagnostic technology such as CR/CT and infrastructure improvement of hospital. The digital imaging materials, especially dry imaging materials which have no use for wet developing process become increasingly important. Dry imaging materials for medical diagnosis are categorized as phtotothermal system and direct thermal system. Photothermal and thermal system have features on number of pixels, system size and throughput respectively. Photothermal system is suitable for integrated processing in major hospitals. Thermal system is suitable for small hospitals, clinics and dispersed processing in each department in major hospitals. Technologies demanded on each system are wide dynamic range, high throughput, processing stability and evenness of image density, arcival ability of image and neutral gray of image tone for suitable as the medical diagnostic image. Technologies of these two systems for contributing these demands are illustrated.

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