Latest advances in camcorder technology

Camcorders have been developed to be compact with high performance. Latest advancement of key technologies and devices such as digital signal processing LSI, six-layer printed circuit board with micro chips, high-speed power lens with linear motor, 103 K pixels 0.7-in LCD electronic viewfinder, and high-energy Li-ion battery are described. High-band format is also explained     

Focusing characteristics of a wide-striped laser diode integratedwith a microlens

We developed a wide-striped laser diode integrated with a microlens that provides good focusing characteristics through a small focusing spot. We calculated and demonstrated that a 60-μm-wide core and a 1.9-μm-high ridge is the best structure for fundamental index-guiding mode oscillation of a wide-striped laser diode. We integrated a wide-striped laser diode with the developed microlens in the Fresnel diffraction held, and demonstrated that a device with a 60-μm-wide core has a minimum focusing spot width of 2.0 μm in the horizontal direction. Also, we estimated the wavefront in the Fresnel diffraction field from the working distance error of a lens designed for a collimated incident beam, and showed that the working distance error, focusing spot width, and sidelobe can be improved by this estimated wavefront     

90-nm process-variation adaptive embedded SRAM modules with power-line-floating write technique

The power consumption of a low-power system-on-a-chip (SoC) has a large impact on the battery life of mobile appliances. General SoCs have large on-chip SRAMs, which consume a large proportion of the whole LSI power. To achieve a low-power SoC, we have developed embedded SRAM modules, which use some low-power SRAM techniques. One technique involves expanding the write margin; another is a power-line-floating write technique, which enables low-voltage write operation. The power-line-floating write technique makes it possible to lower the minimum operating supply voltage by 100 mV. The other techniques involve using a process-variation-adaptive write replica circuit and reducing leakage current. These techniques reduce active power during write operations by 18% and reduce active leakage of the word-line driver by 64%. The prototype SRAM modules achieve 0.8-V operation, and a 512-kb SRAM module achieves 48.4-/spl mu/A active leakage and 7.8-/spl mu/A standby leakage with worst-leakage devices.     

Scientific Screening of Raw Diamond for an Ultraprecision Cutting Tool with High Durability

The wide scattering in tool life of natural mono-crystalline diamond tools is considered to depend on intrinsic crystalline defects due to nitrogen impurities in raw diamond. In this paper, the correlation was investigated between the amounts and types of the impurity evaluated by infrared absorption (IRA) and the crater wear and chipping resistances. As a result, diamonds including less total amount of impurity show larger wear resistance and that with larger amount of B2-aggregates show larger chipping resistance. This suggests that the inspection by IRA can be a useful method for screening of raw diamond for highly durable cutting tools.     

Interconnected power systems with superconducting magnetic energy storage

The objective of this work is to discuss the concept of back‐to‐back interconnection systems with energy storage, especially with a Superconducting Magnetic Energy Storage (SMES) incorporated into a back‐to‐back DC link. In this case, each converter of the back‐to‐back system is used as a power conditioning system for the SMES coils. Since the AC–DC converter can be designed independently of the frequency of the power system, a two‐way switch is connected to the AC side of each converter. This two‐way switch can select the interconnected power systems. By using the two‐way switches, this system can provide the stored energy in the SMES system to each interconnected power system through two AC–DC converters. For instance, lower‐cost power of each power network can be stored through two converters during the off‐peak hours and made available for dispatch to each power network during periods of demand peak. Then this system increases the reliability of electric power networks and enables the economical operations depending on the power demand. This paper describes the unique operations of the back‐to‐back interconnection with SMES and discuses the optimal SMES configuration for a 300‐MW‐class back‐to‐back interconnection. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 164(2): 37–43, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20482     

Sporadic visceral myopathy with inclusion bodies. A light-microscopic and ultrastructural study

We report the clinical and pathologic findings of two patients with sporadic visceral myopathy. Both presented with chronic intestinal pseudo-obstruction that necessitated colectomy. Microscopically, typical changes of primary visceral myopathy were present, including variable fibrous replacement of the muscularis externa and vacuolar degeneration of myocytes. In addition, the muscle cells contained cytoplasmic inclusions that have only been recently reported in visceral myopathy. These inclusions were numerous and easily visible in routine hematoxylin-eosin-stained sections but greatly enhanced by periodic acid-Schiff staining. They were reactive immunohistochemically at their periphery and were seen to be myofibrils at various stages of degeneration on electron microscopy. Inclusions were present in both muscularis externae and muscularis mucosae and were identified in mucosal biopsy specimens, providing a means of diagnosing this type of myopathic change on endoscopic biopsies.     

Simultaneous fabrication of a composite with low thermal expansion and high strength in the eucryptite — yttria-stabilized PSZ system

Low thermal expansion coefficient and high mechanical strength have been attained simultaneously in a composite with microstructures in which the low thermal expansion grains are surrounded by a continuous texture of the grains with high strength. Alloying eucryptite with yttria-stabilized PSZ (partially stabilized zirconia) simultaneously achieved the low thermal expansion coefficient, 1.45 × 10^–6, and the high bending strength, 220 MPa, by adjusting the composition and controlling the microstructures by changing the starting powders and the milling durations. Grain size and reactions between the coupled materials determined the critical processing conditions.     

Series resonant ZCS‐PFM DC‐DC power converter with high‐frequency high‐voltage transformer link for high‐power magnetron drive

This paper presents a single lossless inductive snubber‐assisted ZCS‐PFM series resonant DC‐DC power converter with a high‐frequency high‐voltage transformer link for industrial‐use high‐power magnetron drive. The current flowing through the active power switches rises gradually at a turned‐on transient state with the aid of a single lossless snubber inductor, and ZCS turn‐on commutation based on overlapping current can be achieved via the wide range pulse frequency modulation control scheme. The high‐frequency high‐voltage transformer primary side resonant current always becomes continuous operation mode, by electromagnetic loose coupling design of the high‐frequency high‐voltage transformer and the magnetizing inductance of the high‐frequency high‐voltage transformer. As a result, this high‐voltage power converter circuit for the magnetron can achieve a complete zero current soft switching under the condition of broad width gate voltage signals. Furthermore, this high‐voltage DC‐DC power converter circuit can regulate the output power from zero to full over audible frequency range via the two resonant frequency circuit design. Its operating performances are evaluated and discussed on the basis of the power loss analysis simulation and the experimental results from a practical point of view. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(3): 79–87, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20126