bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on the design of ultraminiature reed switches
Authors: Yokokawa Toshiki , Hinohara Kunio , Nagai Akira 
Published: July 2007

AbstractSince the miniature and high‐density electronic apparatus was developed, the miniaturization of electronic components has been in high demand. The reed switch is not an exception. The reed switches for the P.C.B. mounted miniature relays and the surface mounted miniature relays have also been in high demand. The reed switch which has been used for communication is rather large (46 mm in its entire length and composed of a 28‐mm‐long glass tube). However, the design of the switch itself is almost ideal.This paper discusses the miniaturization limit of the reed switch with respect to the mechanical and magnetic properties. Assuming that the breakdown voltage, the contact rating and the carry current decrease, it was found that the ultraminiature reed switch with glass inner length of 3.6 mm and glass inner diameter of 0.8 mm can be mass‐produced by the existing processing technology.
Characteristics of thin‐film energy‐transfer dye laser with DFB oscillator‐amplifier system
Authors: Muto Shinzo , Uchida Haruki , Nakamura Keiji 
Published: July 2007

AbstractThe operation of many thin‐film ETDL's covering a wide wavelength range from near UV to near infrared has been reported. However, the spectral narrowing and tuning of these solid dye lasers are required inevitably for several applications. Therefore, to obtain this operation, the oscillator with a dynamic distributed feedback (DFB) and the optical amplifier were constructed simply on the thin‐film ETDL waveguide. As a result, the tunable laser emission with narrow spectrum and its amplification were obtained easily over both gain bands of donor and acceptor dye. Thus, this system is available as a compact solid dye laser with wide tuning range.
A high–quality color printing technology by electrophotography
Authors: Tanaka Tomoaki , Hoshino Yasushi 
Published: July 2007

AbstractAlthough color printing technology has actively been developed, the technology to satisfy the tone levels and resolution (the main factors in an image quality), printing speed and stability has not been established.This paper attempts to obtain a high‐quality color printing with high speed and high stability. First, the effects of the tone levels and resolution on the image quality were examined. To find their best combination, evaluation experiments were carried out by using various values of the tone levels and resolutions. The results show that a high‐quality image requires a resolution greater than 6 dots/mm and a tone level greater than 32.Second, it was confirmed that electrophotography with an elliptical laser beam scanning is superior to that with a conventional circular laser beam scanning in the tone level and stability. Experiments were done on the former with the conditions which satisfy the forementioned values, by employing the submatrix‐type dither. As a result, a high‐quality image with a resolution of 6 dots/mm and a tone level of 49 was obtained. Samples processed in this technology show that an image has no false contour and no roughness, that the forede‐scribed conditions for a high‐quality image are justified, and that this technology can be realized.
Fiber excess length in a cable containing optical fiber ribbons
Authors: Hatano Satomi , Kokubun Toshinao , Hogari Kazuo , Katsuyama Yutaka 
Published: July 2007

AbstractA cable containing optical fiber ribbons in a loose tube is promising for high‐density, multifiber and economical communication. This paper discusses the influence of excess fiber length.Assuming that the optical fiber excess length (the difference between the lengths of the optical fiber and its container) causes the optical fiber to bend, the relationship between the excess length and sinusoidal bending radius has been obtained. It was found that the optical losses due to the sinusoidal bend of a graded‐index multinode fiber with core and outer diameter of 50 and 125 μm respectively, were inversely proportional to the square of the minimum radius of curvature. Also, the loss characteristic is the same as that in case of the uniform spiral bend. Based on these results, the method of estimating the optical losses due to the excess length was obtained. It was confirmed that the measured optical loss agreed with the estimated loss.It was found that the excess length ratio β should be restricted between −0.05 and 0.2 percent to minimize the optical losses and fiber failure probability.
Two–dimensional photosensor using a–Si pin diodes
Authors: Senda Kohji , Susas Masahiro , Hiroshima Yoshimitsu , Takamura Tohru 
Published: July 2007

AbstractThis paper proposes a two‐dimensional photosensor composed of an a‐Si pin junction. The photosensor is constructed on the glass substrate. The pixel of the sensor is of a simple structure composed of two photodiodes connected in opposite directions between the vertical and the horizontal signal lines. The photodiode constructed by a‐Si pin junction has the function of the blocking diode, preventing the crosstalk in reading out the signal, in addition to the photoelectric conversion. The sensor is of the sandwich type composed of an a‐Si pin junction, and achieves the store‐and‐read operation with a high speed. A large reset noise is superposed on the input signal in the proposed sensor, but is eliminated by the differential amplifier with the double reading drive, leaving only the light signal. A two‐dimensional 5 × 5 photosensor was constructed experimentally, and the basic operation was verified. The photoelectric conversion characteristics are that the output signal is proportional to the input light with the sensitivity of 50 mV/lux·S and S/N of 12 dB.
An optical tactile sensor using the CT reconstruction method
Authors: Kawashima Toshio , Aoki Yoshinao 
Published: July 2007

AbstractThe tactile sensors used for robotics and electrical artificial hands are designed to provide force information. They are required to have the capability of not only detecting pressure distribution with high sensitivity, but also to carry strength and provide flexibility in grasping objects. This paper proposes a two‐dimensional tactile sensor based on the pressure‐optical transmission conversion system and the principle of computer tomography. The sensor consists of a three‐layered silicon rubber sheet and an array of opto‐electrical elements embedded in the edge of the sheet. The pressure distribution is detected as an optical transmission pattern. The transmission pattern is reconstructed to a two‐dimensional distribution using the algorithm of the computer tomography (CT) pattern reconstruction. The merits of this method are: 1) the sensor is flexible and suitable for grasping objects; 2) the number of components and signal lines is small; 3) the sensor can withstand excessive force; and 4) the sensor can be attached to a curved surface. In this experiment, using thirty‐two pairs of circular sensor arrays, the pressure distribution of 200 sites with 2.5 mm resolution was obtained. This paper describes the design, the mechanism of transduction, and the performance of the tactile sensor.
4–kbit bipolar RAM with on–chip address latch function
Authors: Nambu Hiroaki , Kanetani Kazuo , Yamaguchi Kunihiko , Homma Noriyuki , Todokoro Hideo , Akimoto Kazuhiro , Ogiue Katsumi 
Published: July 2007

AbstractFor speed‐up technologies for bipolar RAMs, an on‐chip address latch function, a new sense circuit using a dummy cell, a Darlington wordline driver, etc., have been reported. However, their effects still have not been clarified. According to the quantitative evaluation of the forementioned circuit technologies, with respect to the speed‐improvement and stable operation of memory cells in this paper, the speed can be improved by 30 percent and no instability of data retention occurs in memory cells even using the Darlington wordline driver. The 4‐Kbit RAM has been fabricated with the forementioned circuit technologies and the 1.5‐μm U‐groove isolation process. The high speed of the mentioned circuits and the stable operation of memory cells have been confirmed by evaluation using the EB tester. The performances obtained are access time of 3.5 ns (by using an on‐chip address latch function, it can be improved to 2.5 ns from the viewpoint of the system) chip area of 12.7 mm2, and power dissipation of 1 W.
Finite–element analysis of plane wave diffraction from dielectric gratings
Authors: Nakata Yasunori , Koshiba Masanori , Suzuki Michio 
Published: July 2007

AbstractAn analysis method based on the finite element method is proposed for solving the problem of diffraction of a plane wave by a dielectric grating. For both the TE and TM wave incidences, a systematic formulation is presented. Although numerous analysis methods have been reported on dielectric gratings, it is necessary in general to divide a grating into several layered planar dielectric gratings when a dielectric grating with an arbitrary profile is analyzed. On the other hand, the finite element method used in this paper enables direct treatment of a dielectric grating with an arbitrary profile without multilayered division. In practice, gratings made of grooves with rectangular, sinusoidal and trapezoidal profiles created on the surface of a semi‐infinite dielectric medium are analyzed. The results of analysis on the diffraction characteristics are presented. Next, as an example for groove gratings with complex geometry, the analysis results of the diffraction efficiency are presented for a holographic grating fabricated at IBM. The analysis results agree well with those by other methods and with experimental values so that the validity and usefulness of the present method are confirmed.
Fabrication of a–Si:H films by coaxial line type microwave hydrogen plasma CVD
Authors: Kato Isamu , Ueda Tetsuya , Hatanaka Kazuhisa 
Published: July 2007

AbstractA double tubed coaxial line type microwave plasma CVD system has been developed for a‐Si:H film deposition using hydrogen and argon gases with pure SiH4 gas as the material gas. The film quality was evaluated as a function of the plasma condition.Since the spreads of hydrogen and argon plasmas were in the range of 2‐3 cm and 8‐9 cm, respectively, the substrate was placed 10 cm from the end of the discharge tube to avoid bombardment of the substrate by high‐energy particles. The film fabricated under hydrogen plasma showed superior characteristics. The film deposited at the substrate temperature between 150 and 200°C were of high quality; predominantly SiH bond rather than SiH2 bond, a large value for the photo‐dark conductivity ratio (σp/σd − 105) and a small density of dangling bonds.A high‐quality film can be fabricated under hydrogen plasma because a large amount of hydrogen radicals covers the film surface, thereby causing a thermal structural relaxation of silane radicals. This relaxation results when the silane radicals increase their surface mobility after the soft landing on the film surface.
Design and performance of high‐power 1.5 μm DFB lasers
Authors: Matsuoka Takashi , Yoshikuni Yuzo , Motosugi George , Enya Mitsuhiro 
Published: July 2007

AbstractA comprehensive design for high‐power DFB lasers is discussed. An anti‐reflection/high‐reflection facet structure and optimized coupling between forward and backward propagation waves in continuous corrugation‐type devices are shown in to be essential for this purpose. By applying the forementioned optimization to 1.5 μm DFB laser parameters, a maximum output power of 45 mW and a quantum efficiency of 37 percent are obtained at 20°C. The devices oscillate in a single‐longitudinal‐mode with a side‐mode suppression ratio of more than 30 dB under 1 GHz sinusoidal modulation.
Composition control of some oxide films by means of a tri–pole magnetron sputtering system
Authors: Fukami Tatsuo , Teshima Osamu 
Published: July 2007

AbstractThis paper describes the newly developed Tri‐Pole Magnetron Sputtering System, which has the third magnetic pole of an electric magnet, or the control pole, in addition to the conventional N and S poles between them. The system can switch the polarity of the control pole through the direction of the coil current so that it can shift the target‐eroded region by the magnetic field configuration. Therefore, film composition can easily be controlled by an appropriate composite target of coaxial disks corresponding to magnetic field configuration, at the same time changing the duty ratio of the current flowing through the control‐pole coil to adjust the sputtering time of each target‐component. The system is superior in both controllability and stability because of its static operation without mechanical moving elements. The switching behavior of the sputtered region is clarified via the target erosion pattern. Then the applicability of the system to the composition control of lead titanate films, etc., is discussed.
A three‐dimensional resist shape simulator and its application to submicron VLSI process
Authors: Member Tetsuo Itoh, , Nonmember Toshiharu Matsuzawa, , Kadota Kazuya , Nonmembers Shuichi Hanashima, 
Published: July 2007

AbstractA three‐dimensional photoresist shape simulator has been developed for the submicron process. Using this simulator, it is possible to analyze and optimize the photoresist process using an arbitrary projector, photoresist, and developer. In this technique, considering the man‐machine interface, the three‐dimensional shape of the photoresist can be shown in a colorgraphic VDT and plotter. Comparing the result of the threedimensional simulation using the contact hole pattern with that of the two‐dimensional simulation, a discrepancy occurs in the dimension less than 1 μm between the two techniques, and it has been found that threedimensional simulation is necessary when the width and depth of the pattern are in the same order. Using the three‐dimensional simulation, a resolution of 0.5 μm cannot be achieved when the wavelength of the light source is 435.8 μm, the numerical aperture of the projection lens N.A. is 0.28, and the coherency s̀ is 0.7. However, such a resolution can be achieved by using the wavelength of the light source of 435.8 nm, N.A. of 0.42, and s̀ of 0.5.
Analysis of reflection and transmission characteristics of step discontinuity in rectangular dielectric waveguides
Authors: Tomabechi Yoshiro , Matsumura J. P. Kazuhito 
Published: July 2007

AbstractThis paper calculates the reflection and transmission coefficient at a discontinuity in rectangular dielectric waveguides. At the discontinuity, waveguides of two different sizes are connected concentrically. Generally speaking, radiation modes generated at the discontinuity in open waveguides make analysis difficult.Here, double Fourier transformation is applied to field distributions at the discontinuity so that a guided and radiation mode can be treated identically. Since the reflection and transmission coefficient can not be obtained immediately by solving the boundary condition equations at the discontinuity, a ratio of electric and magnetic field intensities of the radiation mode is introduced and converged to constant by an iterative approximation. This approximation formula is derived from an orthogonal relation between the guided and radiation mode. If this ratio is converged to a steady value, the reflection and transmission coefficients are converged simultaneously. In addition, the reflection, transmission and radiation power at the discontinuity are calculated numerically. These results are compared with those obtained from the mode matching method which is useful when the discontinuity is so small.The theory in this paper is advantageous in analyzing the discontinuity at a waveguide junction. The analytical method is applicable to an off‐axial junction of the waveguide and the analysis of a rectangular dielectric rod antenna.
NMR fast line‐scan imaging using a line‐shaped focusing field
Authors: Yamada Yoshifumi , Goto Takao , Tanaka Kunio 
Published: July 2007

AbstractA new NMR imaging technique is described. A selective excitation is given in a line‐shaped focusing field. The spin distribution in the one‐dimension line‐shaped excitation region is detected with a linear magnetic field gradient. The methods of generating the line‐shaped magnetic focusing field and its scanning are described together with the selective excitation characteristic. Experiments of imaging with an 819‐kHz pulsed NMR system and their results are shown. The data collection time of the method was examined, showing much shorter time than conventional line‐scanning methods. This is because the spin excitation is carried out only for a necessary region. When a single slice is required, the imaging time can be about the same period as in a conventional NMR‐CT.
Improved integral equation method for electromagnetic scattering problems
Authors: Matsuhara Masanori 
Published: July 2007

AbstractThe integral equation method for electromagnetic‐wave scattering problems has difficulty in that we can not obtain a unique solution when the wave numbers of electromagnetic waves agree with the eigenwave numbers of the system under consideration. In this paper, we derive an integral equation satisfied at arbitrary observation points inside a scattering body and propose a method to place all finite numbers of the observation points (this number agrees with the number of the expansion coefficients for approximating the unknown field function) on an appropriately arbitrary closed curve located inside the scattering body. Through the newly proposed method described in this paper, we can easily avoid an inherent difficulty of an integral equation, compared with the existing methods, specifically, by adding internal conditions and by using integral equations of mixed types. As a numerical example, we solved a case of a plane wave incidence on a perfectly conducting elliptic cylinder. Using the boundary elements method, we carried out numerical calculation and showed that the solution of a high degree of precision can be obtained easily.
A method to measure position and attitude of a tunneling machine
Authors: Nakano Yusuke , Sugimoto Sadao , Arai Hitoshi 
Published: July 2007

AbstractDevelopment of a method to measure the position and attitude of a tunneling machine is required for constructing a curved and long tunnel with a small diameter for communication cables. This paper presents a method to satisfy this requirement. Two coils (“send coils”) are set on the ground to generate an ac magnetic field. Another coil (“search coil”) to detect this magnetic field is set on the tunneling machine under use. This search coil rotates on orthogonal planes, one of which is parallel to the direction of the tunneling‐machine progression. The position and attitude of the machine are calculated from the voltage induced in the search coil. The direction of a component of the magnetic field at an arbitrary position (with reference to the send coils) is essential in this method; this was obtained from theoretical (the finite‐element method) and experimental values. Appropriate dimensions of the search coil were found by introducing “the height/width ratio” and “the winding ratio.” The detection accuracy of this method is about 20 cm on a horizontal plane, and about 2° in attitude, thereby confirming its effectiveness.
A method for analyzing coupled inhomogeneous waveguides supporting two modes and its application
Authors: Ono Kazuo , Sawa Shinnosuke 
Published: July 2007

AbstractIn this paper, the successive approximate method is used to treat the two‐mode loose coupled inhomogeneous systems where the propagation constants and coupling coefficients are functions of the propagation distance. That is, the successive approximate method is used to analyze in a general way the response of the system of coupled inhomogeneous equations. As a result, two or three comprising conditions are obtained for the devices to be used as mode transformers. To verify the correctness of the present method, the results are compared against those of the so‐called approximate integral method applied to the inhomogeneous systems in which only the coupling coefficients are varied with propagation distance. It is indicated that similar results are obtained. For example, in the case of the tapered lens medium, which has previously been treated from a wave point of view, no contradiction is observed. Finally, to demonstrate application of the present method, we use two‐mode directional couplers that are simple to construct and have only small losses.
Analysis of the operation of surface‐emitting‐type optical threshold device
Authors: Nitta Jun , Iga Kenichi 
Published: July 2007

AbstractThis paper proposes a surface‐emitting‐type optical threshold device and analyzes its characteristics. For a surface‐emitting laser resonator with a saturable absorber, its static characteristics and small signal analysis with a current or light injection are obtained from rate equations. As a result, the possibility of an optical threshold device which operates with a practical optical energy of approximately 30 kW/cm2 has been shown. Furthermore, it has been shown that the optical threshold varies by controlling an injection current, and that AND and OR logics are possible with one device. As a result of small signal analysis, the device is shown to have a bandwidth of approximately 1 GHz.
ISFET incorporated in a differential amplifier
Authors: Tsukada Keiji , Maruizumi Takuya , Miyagi Hiroyuki 
Published: July 2007

AbstractThe output of the ISFET (Ion Sensitive Field Effect Transistor) was obtained as a voltage signal. To achieve the temperature compensation, a differential amplifier composed of ISFET and MOSFET was fabricated. For integration, the process and circuit designs for the ISFET and MOSFET were done carefully by considering both the device fabrication process and the electrical properties of the device. Polycrystalline silicon was used for the connection between the devices and the MOSFET gate electrode. The entire device surface was covered with Si3N4/SiO2 to ensure the waterproof properties of the device. As a result, the MOSFET could be located near the ISFET and both FETs could be processed in the same manner. The fabricated ISFET could produce the voltage signal in accordance with the change in the gate membrane potential of the ISFET. The sensitivity of the device was 49 mV/pH. In addition, temperature compensation in the ISFET was achieved and the temperature coefficient was −0.8 mV/°C.
DC and switching characteristics of inverted structure AIGaAs/GaAs HBT's
Authors: Nozu Tetsuro , Akagi Junko 
Published: July 2007

AbstractInverted type, or collector‐top A1GaAs/GaAs HBT's and their ring oscillators have been fabricated and dc characteristics have been evaluated. In case of collector area SC/external base area S < 0.8, the external base current is large and hFE is reduced. In case of SC/S > 0.8, the upper limit of hFE is about 20. The ring oscillator characteristic in a DCTL ring oscillator is tpd = 63 ps and the one in an NTL ring oscillator is tpd = 77 ps. An emitter‐top HBT with impurity profile and structural shape identical to those for the proposed collector‐top HBT is used for a ring oscillator. The characteristic of the latter have been estimated by means of SPICE and compared with the measured results for the collector‐top type. It is found that the collector‐top HBT has a higher switching speed and is more suited as a high‐speed logic device than the emitter‐top HBT.