Okuda M.,NHK Science and Technical Research Laboratories |
Okuda M.,Tokyo Institute of Technology |
Miyamoto Y.,NHK Science and Technical Research Laboratories |
Miyamoto Y.,NHK Engineering System Inc. |
And 4 more authors.
Journal of Applied Physics | Year: 2015
Current-driven magnetic domain walls in magnetic nanowires have attracted a great deal of interest in terms of both physical studies and engineering applications. The anomalous Hall effect measurement is widely used for detecting the magnetization direction of current-driven magnetic domains in a magnetic nanowire. However, the problem with this measurement is that the detection point for current-driven domain wall motion is fixed at only the installed sensing wire across the specimen nanowire. A potential solution is the magnetic domain scope method, whereby the distribution of the magnetic flux leaking from the specimen can be analyzed directly by contact-scanning a tunneling magnetoresistive field sensor on a sample. In this study, we fabricated specimen nanowires consisting of [Co (0.3)/Pd (1.2)]21/Ta(3) films (units in nm) with perpendicular magnetic anisotropy on Si substrates. A tunneling magnetoresistive sensor was placed on the nanowire surface and a predetermined current pulse was applied. Real-time detection of the current-driven magnetic domain motion was successful in that the resistance of the tunneling magnetoresistive sensor was changed with the magnetization direction beneath the sensor. This demonstrates that magnetic domain detection using a tunneling magnetoresistive sensor is effective for the direct analysis of micro magnetic domain motion. © 2015 AIP Publishing LLC.
Nishimoto Y.,NHK Japan Broadcasting Corporation |
Kawakita H.,NHK Japan Broadcasting Corporation |
Yamamura C.,NHK Japan Broadcasting Corporation |
Nakagawa T.,NHK Japan Broadcasting Corporation |
Inoue T.,NHK Engineering System Inc.
Digest of Technical Papers - IEEE International Conference on Consumer Electronics | Year: 2014
This paper presents is a downloadable conditional access system (CAS) for advanced satellite broadcasting with 4K/8K UHDTV. This CAS can perform secure access control and has security functions such as key data processing and encryption processing that can be securely updated through broadcasting or communications functions. A prototype TV receiver with the downloadable CAS was developed in order to evaluate feasibility of the proposed system. © 2014 IEEE.
Sugimoto T.,NHK Science and Technical Research Laboratories |
Ando A.,NHK Science and Technical Research Laboratories |
Ono K.,NHK Engineering System Inc. |
Morita Y.,Foster Electrical Co. |
And 3 more authors.
Journal of the Acoustical Society of America | Year: 2013
A lightweight push-pull acoustic transducer using dielectric elastomer films was proposed for use in advanced audio systems in homes. The push-pull structure consists of two dielectric elastomer films developed to serve as an electroactive polymer. The transducer utilizes the change in the surface area of the dielectric elastomer film, induced by an electric-field-induced change in the thickness, for sound generation. The resonance frequency of the transducer was derived from modeling the push-pull configuration to estimate the lower limit of the frequency range. Measurement results presented an advantage of push-pull driving in the suppression of harmonic distortion. © 2013 Acoustical Society of America.
Honda Y.,NHK Science and Technical Research Laboratories |
Miyakawa K.,NHK Science and Technical Research Laboratories |
Kubota M.,NHK Science and Technical Research Laboratories |
Nanba M.,NHK Engineering System Inc. |
Egami N.,Kinki University
2013 26th International Vacuum Nanoelectronics Conference, IVNC 2013 | Year: 2013
A new active-matrix Spindt-type field emitter array for a FEA-HARP (field emitter array-high-gain avalanche rushing amorphous photoconductor) image sensor was designed. Simulation and experimental results showed that the new active-matrix drive circuit can shorten the response time and can potentially meet the HDTV standard. © 2013 IEEE.
Kanazawa M.,NHK Engineering System Inc.
Journal of the Society for Information Display | Year: 2013
Monochrome reflective-type displays are widely used for portable reading applications such as electric papers because this type does not need a back light unit and can be used outdoors for a long time. Color reflective-type displays without back light units are desired to expand the market further. The current color reproduction is based on three sub-pixel red, green and blue (RGB) methods, and when used in reflective type, its luminance is reduced to a third of that of monochrome type. Adding a white sub-pixel to the current method can improve the luminance, making the sub-pixel number four. However, in the case of a high resolution display with a four-sub-pixel method, the pixel structure is complex, and the luminance improvement may be limited. Instead of increasing the sub-pixel number, two sub-pixel methods are investigated. These methods can improve luminance with limited color gamut. The performances are compared with those of other methods quantitatively. © Copyright 2013 Society for Information Display.