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Gamagōri, Japan

Mutoh K.,Aoyama Gakuin University | Nakagawa Y.,Itoh Optical Industrial Co. | Hatano S.,Hiroshima University | Kobayashi Y.,Aoyama Gakuin University | And 2 more authors.
Physical Chemistry Chemical Physics | Year: 2015

Biradicaloid species have been extensively studied for their characteristic features in electric conductivity, magnetism, and optical nonlinearity. Theoretical investigations of rigid biradicaloid species have been suggesting that they are represented as a resonance hybrid of open-shell biradical and closed-shell quinoid structures. However, much is still unknown about flexible biradicaloid species whether the activation free energy barrier between these states exists or not. Herein, we investigated the thermal isomerization from the photogenerated unstable biradical to the stable quinoid species observed for the photochromic dimer of a bisimidazolyl radical and found that the large negative activation entropy for the valence isomerization causes the activation free energy barrier between these two states. © the Owner Societies 2015. Source

Fujii Y.,Toyohashi University of Technology | Imai T.,Toyohashi University of Technology | Miyamoto Y.,Toyohashi University of Technology | Ueda N.,Toyohashi University of Technology | And 10 more authors.
Surface and Coatings Technology | Year: 2016

Tetrahedral amorphous carbon (ta-C) films were prepared on cutters which are used for engraving. Engraving tests were performed on metal plates using non-coated and ta-C-coated cutters, under dry machining conditions, without oil. Generally, the metal plate is engraved using a cemented carbide (WC-Co) cutter, which uses oil for the cutting process, to fabricate a nameplate. The oil causes a high environmental load and complicates the machining process. Therefore, from an industrial viewpoint, there is a need for a dry machining process. The ta-C film is a hydrogen-free diamond-like carbon film with a high mechanical hardness. In this study, droplet-free ta-C films were prepared on WC-Co cutters using a T-shape filtered arc deposition method. The work materials used in the engraving tests were aluminum, copper, and brass. The results of the engraving tests demonstrated suppression of metal adhesion to the cutting edge, prevention of chipping of the cutting edge, and a decrease in cutting resistance during engraving when a ta-C film had been coated onto the cutting edge. In addition, burr and residue on engraved grooves were also suppressed by using a ta-C-coated cutter. The ta-C film coating offered a remarkable improvement in the engraving performance of a WC-Co cutter in the dry machining process. © 2016 Elsevier B.V. Source

Kaarna A.,Lappeenranta University of Technology | Nishino K.,Toyohashi University of Technology | Miyazawa K.,Itoh Optical Industrial Co. | Nakauchi S.,Toyohashi University of Technology
Color Research and Application | Year: 2010

A michromatic (microscope plus chromatic) scope is a device that enhances the color discrimination between two spectral color datasets. Three spectral filters are required, instead of the conventional red, green, and blue filters, for the implementation of a michromatic camera. In this study, we describe two approaches to the design of these filters: in the first case, the design is based on the direct optimization of the filter characteristics (transmittance), whereas in the second case, the design is based on the nonnegative tensor factorization (NTF) of the spectral datasets. A michromatic camera can be implemented using these filters along with compatible postprocessing in-camera firmware. Here, we performed experiments with two color datasets: one comprising skin and vein colors, and one comprising skin and cosmetics colors. These were further divided into a training set and a test set. The filters were defined using the training set, and the operation of the filters was tested and magnified using the test set. Our experiments demonstrated that the proposed approaches are suitable for color discrimination. For the first color dataset, the enhancement produced using the optimized filters was up to 252% of the original value, and the average color difference ΔE was increased from 2.82 to 9.93. NTF and preprocessing further enhanced the ΔE up to 21.84. For the second color dataset, NTF and postprocessing enhanced the ΔE from 4.33 to 29.19. The proposed discrimination enhancement could be physically implemented in a designated digital charge-coupled device camera with proper filter installation and compatible postprocessing. © 2010 Wiley Periodicals, Inc. Col Res Appl, 35, 101-109, 2010; Published online 7 January 2010 in Wiley InterScience (www.interscience.wiley.com). Source

Tanoue H.,Toyohashi University of Technology | Kamiya M.,Toyohashi University of Technology | Kamiya M.,Itoh Optical Industrial Co. | Suda Y.,Toyohashi University of Technology | And 7 more authors.
Japanese Journal of Applied Physics | Year: 2011

Diamond-like carbon (DLC) film is sometimes removed using oxygen plasma in order to reuse workpieces such as cutting tools and press molds. In this study, an oxygen-dominated plasma beam was generated by converting the cathodic carbon arc plasma beam formed in T-shaped filteredarc-deposition (T-FAD) in order to investigate the feasibility of using the plasma beam for the removal of DLC film. When the oxygen (O2) gas flow rate was relatively high (50 ml/min) and the substrate was biased (DC -500 V), the plasma beam in front of the substrate was confirmed to contain a considerable amount of excited oxygen atoms, since an atomic oxygen spectral line (777 nm) emitted from the plasma beam had relatively strong radiation intensity. The plasma beam was irradiated on a tetrahedral amorphous carbon film, a hydrogen-free sp3-rich DLC film, prepared on a hard alloy (WC with 6wt% Co binder) substrate. It was found that a plasma beam generated with an appropriate O2 gas flow rate and applied substrate bias was able to etch the DLC film proportionally to the treatment time. The surface was not roughened when the treatment time was 1.5 times longer than the intended time to remove a given thickness of DLC film. © 2011 The Japan Society of Applied Physics. Source

Itoh Optical Industrial Co. and Koito Manufacturing Co. | Date: 2012-06-06

An automotive lamp includes an LED, a substrate that mounts the LED, a reflector that reflects the light emitted from the LED, and an projection lens having an incident surface, which receives the light reflected by the reflector, and an emission surface that emits the light toward a front area of the automotive lamp. A fine asperity structure is formed on the incident surface of the projection lens. The fine asperity structure includes recesses or raised portions formed with the pitch less than or equal to the visible light wavelength.

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