2015 VOL.70 NO.11

  Special Reports

Total Solutions Based on Toshiba Lighting Technologies over 125 Years

At Time of 125th Anniversary of Toshiba Lighting Business
IBI Yoichi

Toshiba's 125 Years of Progress in Lighting Business and Approaches to LED Lighting Technologies
One hundred and twenty-five years have passed since Ichisuke Fujioka established Hakunetsu-sha & Co., Ltd., one of the forerunners of Toshiba, and succeeded in the practical application of Japan's first carbon-filament lamps in 1890. Toshiba has been developing various types of technologies as a leading company in the lighting field during this period, such as light sources, lighting circuits, luminaires, and lighting control devices. We have been contributing not only to the development of lighting products but also to the growth of lighting culture in Japan through various educational activities.
With the recent dissemination of light-emitting diode (LED) lighting, which possesses numerous advantages including energy saving, long lifetime, compactness, and light weight compared with conventional lighting, we have been actively focusing on the development of LED lighting technologies to offer new value to users.

Latest Technologies Enhancing Performance of Self-Ballasted LED Lamps
Self-ballasted light-emitting diode (LED) lamps with high luminous efficiency have been rapidly expanding in the market, reflecting the increased awareness of the need for energy conservation in recent years.
Toshiba Lighting & Technology Corporation has been developing and supplying various products featuring high power output, high efficiency, and improved light spread and light quality since its release of a night-light type self-ballasted LED lamp in 2002. As part of these efforts, we have developed a gallium nitride (GaN) power device mounted in a control gear for LED lamps, and released a dimmable self-ballasted LED lamp for replacement of 100 W type halogen lamps for the first time in the industry in 2015. We are also developing self-ballasted LED lamps with a clear bulb surpassing the brilliance of tungsten filament.

Latest Technologies for Lighting Control Systems in Office Buildings
NISHIGAKI Hidenori / KOTANI Tomoko
In addition to air-conditioning systems in office buildings, lighting facilities also consume large amounts of electricity and are therefore the targets of building energy efficiency and conservation measures.
Toshiba Lighting & Technology Corporation has been developing and supplying optimal lighting control systems equipped with motion sensors, light control sensors, an automatic scheduling function, and other functions to efficiently reduce energy consumption in accordance with customers' needs. We have also developed wireless-controlled luminaires that can be easily installed because no light control wiring is required. Furthermore, we are engaged in the development of a building operation and management system that combines lighting facilities with other facilities, including air-conditioning systems and security systems, and complies with the BACnet(†) data communication protocol for building automation and control networks. We are aiming to create comfortable and energy-saving office lighting by applying our proprietary technologies for light-emitting diode (LED) lighting and lighting control systems.

47 kW LED Lamp for Reduction of Power Consumption in Photochemical Reaction Processes
NAGANO Nobuhisa / IWAO Akio / ISHIKAWA Tatsuaki
Toshiba Lighting & Technology Corporation has been engaged in the research and development of light sources for photochemical reaction processes developed by Toray Industries, Inc. for the synthesis of caprolactam, a raw material for nylon. We manufactured mercury lamps for these processes in the 1960s, and have been supplying sodium lamps with improved efficiency up to the present time.
In cooperation with Toray Industries, we have now developed a light-emitting diode (LED) lamp with a large output power of 47 kW to replace existing sodium lamps, with the aim of reducing power consumption. This LED lamp achieves an approximately 30% reduction in power consumption compared with that of a sodium lamp by applying the following technologies: (1) a high-density packaging technology in which a large number of LEDs are mounted on a 16-sided polyhedral structure, (2) a water-cooled system achieving a lower junction temperature for each LED, and (3) a constant-current power supply offering high efficiency and compactness.

Latest Technologies for Ultraviolet Lamp and LED Modules Corresponding to Various Industrial Applications
TAUCHI Akihiko / FUJIOKA Atsushi / MINEYAMA Tomoyuki
Ultraviolet (UV) lamps, which can efficiently provide short-wavelength UV irradiation with high energy according to the application, are installed in production facilities and products in a variety of industrial fields.
In response to market needs, Toshiba Lighting & Technology Corporation is continuously engaged in the development of UV lamps and systems and is also developing UV light-emitting diode (LED) modules as a next-generation light source. We have been supplying a UV irradiation module for high-performance liquid crystal display (LCD) panel manufacturing equipment, which was realized by integrating our established UV lamp and module technologies including optical systems and devices. We have also developed and released a dedicated high-pressure mercury lamp for marine ballast water treatment systems in cooperation with system manufacturers, in order to prevent ecosystem degradation by alien species in ballast water. Moreover, we are developing UV LED mounting modules for the printing and LCD panel markets, which are expected to further expand in the future, through the application of our cooling and optical design technologies.

LED Lighting Illumination of Phoenix Hall at Byodo-in Temple Expressing Sanctuary's Timeless Grandeur
KAJIMURA Toshiya / OKA Yoshiro / BETSUDA Nobuhiko / MATSUSHITA Susumu
Byodo-in Temple, located in Uji City, Kyoto, was named a Word Heritage Site in 1994 as one of the Historic Monuments of Ancient Kyoto. The Phoenix Hall and several other objects at Byodo-in are also designated as National Treasures in Japan, and the Phoenix Hall is particularly well known for its beautiful appearance reflected on the surface of the scenic pond that lies in front of it. A light-emitting diode (LED) illumination project for the Phoenix Hall was implemented as part of a refurbishment of the hall starting in September 2012.
As a participant in this project, Toshiba Lighting & Technology Corporation formulated the illumination plan with the aim of expressing the beauty of the Phoenix Hall at the time of its establishment by means of lighting, and preserving it for future generations. For this purpose, we developed compact high-output LED floodlights with a narrow-angle light distribution. The use of these LED floodlights has achieved a reduction of approximately 55% in overall power consumption compared with the former halogen floodlights.

GaN-on-Si Technologies for LED Lighting Achieving Reduced Cost and Increased Output Power
GaN-on-Si technologies,in which a gallium nitride (GaN) layer is epitaxially grown on a silicon (Si) substrate instead of a sapphire substrate,have been attracting attention as a means of realizing low-cost white light-emitting diodes (LEDs).
Toshiba has developed GaN-on-Si technologies for blue LEDs as a light source for white LEDs using 8-inch Si wafers,and achieved high-power blue LEDs with emission characteristics equivalent to those fabricated using the sapphire-based process. In order to improve the efficiency of GaN-on-Si-based blue LEDs,we have developed a novel technology using silicon nitride (SiN) multiple-modulation interlayers to reduce threading dislocation densities (TDDs) in the GaN thin film. This TDD reduction technology makes it possible to improve external quantum efficiency at the high temperature required for white LED lighting. We have also developed a multijunction type high-voltage LED for LED lighting with large luminous flux based on a thin-film flip-chip LED (MJTF-LED) with high power and high luminous efficacy.

"TRI-R" White LED Technology to Reproduce Emission Spectrum of Natural Light
With the aim of reproducing the emission spectrum of natural light, Toshiba Materials Co., Ltd. has been engaged in the development of white light-emitting diodes (LEDs) featuring a continuous spectrum in the visible light wavelength range and high color rendering characteristics. As a result of these efforts, we have developed the "TRI-R" white LED technology employing a purple LED chip for excitation light with a combination of our proprietary blue/green(yellow)/red phosphors.
Applying the TRI-R technology, we have developed LED luminaires suitable for applications requiring high color reproduction, such as museums and restaurants, and are also developing lighting modules in the medical field such as shadowless lights for surgical illumination devices.


  Feature Articles

Image Denoising Technology Using Sparsity Distillation
KAWATA Satoshi / MISHIMA Nao / KANEKO Toshimitsu
In the field of digital cameras, the decreasing number of incident photons accompanying the miniaturization of sensors has resulted in increased image noise, with a consequent degradation of image quality. In the field of diagnostic imaging systems as well, deterioration of visibility has occurred as an outcome of higher photography speeds. Expectations have therefore been focused on the denoising of digital images captured by these devices.
Toshiba has developed an image denoising technology that can restore noisy image-capture signals to true signals utilizing sparsity, a statistical property of the image-constructing signals. We have conducted simulation experiments and confirmed that the newly developed technology can effectively remove noise from natural images while preserving intricate textures, and that it achieves higher quantitative evaluation values compared with another state-of-the-art image denoising method. This technology is expected to contribute to improvement of the image quality of various digital image processing products.

Bulk Magnetic Material Using Nanoparticles for High-Frequency Communication Equipment
SUETSUNA Tomohiro / HARADA Koichi / SUENAGA Seiichi
Bulk magnetic materials possessing both high permeability and low loss in the high-frequency band are currently attracting attention as key materials to achieve stable communication and compactness in various types of communication equipment.
In order to satisfy these requirements, Toshiba has developed a bulk magnetic material formed by compacting iron-cobalt-aluminum (FeCoAl)-system core/shell magnetic nanoparticles of metal/oxide with a resin. The FeCoAl-system core/shell nanoparticles make it possible to synthesize bulk material of millimeter-order thickness due to their high oxidation resistance despite their small particle size of approximately 20 nm. From the results of experiments, we have confirmed that the synthesized bulk magnetic material achieves a relative permeability of 3.2 and a loss factor of approximately 0% at 1 GHz. This performance is sufficient for application of the bulk magnetic material to communication equipment in the high-frequency band.

Die-Bonding Material and Sintering Joining Technology for Power Semiconductors Allowing Operation at High Temperatures
HIRATSUKA Daisuke / SASAKI Akihiro / IGUCHI Tomohiro
Power semiconductors are widely used in various fields including household appliances, industrial motors, vehicles, and energy transmission and distribution systems. With their operating temperatures showing a rising tendency due to the increasing demand for higher efficiency as well as the application of silicon carbide (SiC) semiconductors, the junction temperature of such devices is expected to exceed 200°C. It is therefore necessary to develop a heat-resistant die-bonding material to bond chips to substrates.
To address this issue, Toshiba has focused on a silver (Ag) nanoparticle material as a die-bonding material that possesses superior heat radiation characteristics and can withstand high temperatures exceeding 200°C. In order to realize a die-bonding material with higher reliability than existing materials, we have also developed a metal salt solution-nanoprecipitation (MS2NP) method as a countermeasure against the degradation of die attachments consisting of sintered Ag nanoparticles.

36/40.5 kV Solid -Insulated Switchgear for Global Power Distribution Market
TARUI Masakuni / MIYAUCHI Yasuhisa / SEKIMORI Yuki
Since sulfur hexafluoride (SF6) was listed as one of the targeted greenhouse gases under the quantified emission limitation and reduction objectives of the Kyoto Protocol adopted at the Third Session of the Conference of the Parties to the United Nations Framework Convention on Climate Change (COP3) in 1997, demand has been growing for switchgears that do not use SF6 gas as their main insulation medium.
Toshiba released 24 kV and 36 kV solid-insulated switchgears (SIS) in 2002 and 2004, respectively. Since then, we have been steadily installing these products as replacements for cubicle type gas-insulated switchgears (C-GIS), which were the leading products in medium-voltage systems in Japan. Based on this accumulated experience, we have now developed a 36/40.5 kV SIS for the global power distribution market. The newly developed SIS is compliant with the International Electrotechnical Commission (IEC) standards and has also been modified to meet various international requirements for power distribution systems. By completely reconsidering the structural design, we have succeeded in making the new SIS smaller and lighter than a conventional SIS.

"Shared Board" 24-inch Touch Display Offering Interactive Signage Solutions
ARIYOSHI Masaaki / MORIMOTO Teruyuki / IKEDA Yusuke
Accompanying the widespread dissemination of visual products centering around liquid crystal display (LCD) TVs for home use and the rapid expansion of tablets and smartphones with touch displays for personal use, display devices for business use such as digital signage devices can also now be seen more frequently.
Toshiba Lifestyle Products & Services Corporation has released the "Shared Board" touch display for business use equipped with a full high-definition (Full HD) (1,920 × 1,080-pixel) 24-inch electrostatic capacitance type panel. Although the size of the display is relatively small for a signage display, the Shared Board features a 10-point multi-touch function that allows simultaneous operation by multiple users. Applying the Android(†) platform, which makes it possible to construct various systems by means of users' apps without changing the hardware, the Shared Board offers solutions for a wide range of business situations as an interactive signage device.


  Frontiers of  Research & Development

Architecture Exploration Platform for Next-Generation Solid-State Drives

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