2007Research papers

1.Method for Predicting Drowsiness

Masatoshi Yanagidaira, Mitsuo Yasushi

Summary

We developed a method for predicting drowsiness in drivers based on changes in the heart rate. The ability to predict drowsiness early when drivers do not yet feel drowsy, even if they show signs of drowsiness, is useful for preventing drivers from falling asleep at the wheel. The heart rate is affected by the ambient temperature, the posture of drivers, and their mental state. Furthermore, signs of drowsiness can be seen in decreasing heart rate. And drowsiness is the critical factor for drivers because most of the time ambient temperature or posture do not change much while driving. Previous research focused on detecting the napping propensity of drivers. However, the detection time for that method is often too long to prevent napping because drivers may already feel drowsy by the time detection is complete. To measure the heart rate of drivers easily, we placed electrodes on both sides of a steering wheel or steering wheel cover and devised a method for predicting drowsiness based on changes in the heart rate. This paper describes the structure and operation of the device, and reports the result of user test. It revealed that these subjects had strong interest of watching their changes of heart rate while driving. And we obtained reasonable results on the reliability of this device.

Click for Details (PDF 1.6 MB)
in Japanese

2.A music recommendation system

Satoshi Odagawa, Yasuteru Kodama, Shinichi Gayama, Fumio Matsushita, Yasunori Suzuki

Summary

We developed a Music Recommendation System which can search and replay a tune suitable for the user's mood while driving from a large number of tunes stored in a music recording device by specifying a search word such as "Bright", "Exciting", "Quiet", "Sad" or "Healing".
We selected the five retrieval words above because we thought that they expressed the impression of music and are suited to a user's feeling while driving.
The replayed tune was searched by calculating the matching level of the tune and retrieval words based on "the level of the retrieval feature" and "the level of the music feature" and the tune was recommended to the user.
"The level of the music feature" was defined as the value which was obtained by analyzing the content of music based on Key, Harmony Variable Level, Beats Per Second, Maximum Beat Level, Maximum Signal Level and Average Signal Level.
"The level of the retrieval feature" was defined as the value which was obtained by weighting based on the impression of each of the retrieval words in relation to the image of music.
In addition, the probability of searching tunes the user will like has been improved by studying the user's preferences.
Moreover, the system can recommend suitable music corresponding to the current conditions of time, weather and traffic conditions.

Click for Details (PDF 608 KB)
in Japanese

3.Mitigating Difficulties of an Utterance Timing for Speech Recognition in Car Navigation Systems

SoichiToyama, Yoshihiro Kawazoe, Hajime Kobayashi, Ikuo Fujita, Tadayasu Kaneko, Jun Oosugi, Takehiko Shioda

Summary

In order to improve the ease of use of the voice operation function in our car navigation, we performed a usability test of the function and investigated the factor s involved in recognition obstruction. We found that it was difficult for the user to utter a voice command at the correct timing. As a result of examining possible improvement methods, we confirmed that it was effective to make a combination of improvements in the display and the operation sequence together.

Click for Details (PDF 1.2 MB)
in Japanese

4.Trial production of automotive robot

Kohei Ito, Ryujiro Fujita, Naohiko Ichihara, Hiroaki Shibasaki, Nobuyuki Satou, Tomohiro Adachi

Summary

This paper introduces an automotive robot called "driving partner", which tries to show empathy with drivers to support them. As part of our ongoing examination of automotive products with new concepts, a trial product of this type was designed with three main keywords; "Robot and driver's hearts are linked ", "Watching over the driver gently (driving gently)", and "Enjoying the journey with the driver". This automotive robot was presented at some public exhibitions, and the results of the questionnaire distributed there showed that many people understood about the concept of automotive robot very well.

Click for Details (PDF 3.3 MB)
in Japanese

5.Development of "Digital Revise Engine"

Taro Asakawa, Yukio Hayashi, Seiji Harada, Koichi Katsuya, Yoshinori Abe, Tetsuya Takahashi, Koji Takahashi, Kenji Mito, Yoshitaka Tanaka, Kazuhiro Watanabe, Takeshi Ito

Summary

In this paper, a new error concealment technique, "Digital Revision Engine", for the ISDB-T(Integrated Services Digital Broadcasting-Terrestrial) system is described.
For mobile reception, the ISDB-T system shows better performance compared with the analog broadcasting. However, transmission errors occur when it moves between buildings or moves at high speed. Due to these transmission errors, video errors and audio errors occur.
To solve this problem, a new error concealment technique, "Digital Revision Engine", was developed. As a result, video errors and audio errors have been reduced by this new error concealment technique.

Click for Details (PDF 1.5 MB)
in Japanese

6.The Development of ISDB-T Receiver for Automotive

Kazuhiko Uchiyama

Summary

We developed an ISDB-T Receiver for Automotive that is able to receive both HDTV (High-Definition Television broadcasting and "One-segment" broadcasting.
To improve the broadcasting reception sensitivity of the automotive receiver, we applied two tuner carrier diversity and a media processor that enabled the error correction technology of the image and the sound.
We introduced the ISDB-T Receiver for Automotive (GEX-P7DTV, GEX-P9DTV) into the market on November, 2005.

Click for Details (PDF 2 MB)
in Japanese

7.Development of HDD car navigation products for 2006

Yoshiya Nonaka, Shunichi Kumagai, Kazuo Murata, Toru Oda, Toshiyuki Murata, Tomohisa Tsukui, Nobuo Tarui, Noritaka Nii, Kentarou Yamamoto, Takeshi Matsuoka, Yasutoshi Maekawa, Ryoji Sugino, Masashi Aoyama, Yoshio Sekine, Nobuo Shinonaga, Hirobumi Iwaji, Hiroki Kato, Takashi Hashinuma

Summary

This document describes the features of WVGA graphics monitor, "Smart loop" and Electronic Music Distribution on the HDD-based car navigation products "AVIC-VH009","AVIC-VH009MD","AVIC-XH009","AVIC-ZH009" and "AVIC-H009". These car navigation products can display high resolution graphics by the WVGA monitor, and realize the "Smart loop"model of accumulative probing, and these products, with the exception of "AVIC-VH009" can transmit music that was purchased through a PC or through the "Anymusic" service.

Click for Details (PDF 3.1 MB)
in Japanese

8.ITS technology related to car navigation

Koichi Nagaki

Summary

This paper presents the history of car navigation, the technology behind its hardware and software, and the environment of ITS regarding car navigation systems. Car navigation systems have become a convenient means to obtain traffic information and connect to mobile phones. The latest car navigation systems have also incorporate camera technology and car control information.

Click for Details (PDF 1.7 MB)
in Japanese

9.The present status and outlook of Organic Light Emitting Diode (OLED) displays for vehicle

Hitoshi Nakada

Summary

Organic Light Emitting Diode (OLED) displays are suitable for vehicle applications because they have particular characteristics such as a high contrast, a relatively high speed of operation and stability at low temperature. Currently, they are adopted in the display parts of car audio systems and meters.

Click for Details (PDF 616 KB)
in Japanese

[Introduction of Pioneer Group related R&D]
Introduction to the Mobile System Development Center

Hitoshi Ando, Shizuo Kakiuchi, Takehiko Shioda, Hiroyuki Kamijo, Tomoe Saito

Summary

Mobile Systems Development Center is composed of three departments, the Automotive Systems Department,the Digital Mobile Receiver Department and the Sound Technology Department. We are developing the elemental technologies related to the car electronics such as a platform for car navigation systems, applications of vehicle camera-images, music agent, voice recognition, and ISDB-T receiver for automotive.
Moreover we are researching technological trends and the technological elements of ITS(Intelligent Transport System), the network applications of car navigation, and approaches for safety which are necessary for the car electronics in the future.

Click for Details (PDF 1.9 MB)
in Japanese

1.Active Matrix Display Using Organic Light-Emitting Transistors

Kenji Nakamura, Takuya Hata, Atsushi Yoshizawa, Katsunari Obata, Hiroyuki Endo, Kazuhiro Kudo

Summary

We have developed novel metal-insulator-semiconductor-type organic light-emitting transistors (MIS-OLETs), and have improved the characteristics of the MIS-OLETs by optimizing the device structure. The MIS-OLET shows a maximum drain current of ID = -149μA, maximum luminance of 1034 cd/m2 (VD = -20 V, VG = -50 V) and an On/Off current ratio over 104. In addition, we have demonstrated an active matrix display using these MIS-OLETs fabricated on a plastic substrate.

Click for Details (PDF 1.8 MB)
in Japanese

2.A study on degradation of OLEDs high temperature storage

Satoshi Miyaguchi, Hiroshi Ohata, Akira Hirasawa

Summary

We studied the degradation of Organic Light Emitting Diodes (OLEDs) resulting from high temperature storage using the Backside SIMS analysis and several other analysis methods. We observed mixing of the Alq3, (the emitting and electron transport layer material) and the hole transport layer material, while keeping their molecular states, above the glass transition temperature of the hole transport layer material. We also found that the diffusion of the Li and the Cs elements, the electron injection layer materials, to the Alq3 layer is caused by high temperature storage. The diffusion of the Cs was larger than that of the Li, and the device characteristics had conspicuous degradation.

Click for Details (PDF 992 KB)
in Japanese

3.Fabrication of Organic Thin-Film Transistors Using Printing Method

Takashi Chuman

Summary

Silicon is widely used as a Semiconductor Material of TFT in Active Matrix Flat-Panel Display. On the other hand, Organic TFT using an Organic active layer has been developed actively in Japan and many other countries in recent years, and printing materials and processes for building Organic TFT attract special attention. In this report, I expound on the technology of Printable Organic TFT with some announced studies.

Click for Details (PDF 608 KB)
in Japanese

4.Correlation of hole mobility, exciton diffusion length, and solar cellcharacteristics in phthalocyanine / fullerene organic solar cells

Yuhki Terao, Hiroyuki Sasabe, Chihaya Adachi

Abstract

The authors investigated heterojunction organic solar cells composed of different metal phthalocyanines (MPcs, M = Fe, Co, Ni, Cu, and H2)/fullerene (C60) and compared the solar cell characteristics with the field-effect hole mobilities (μh) and exciton diffusion length (Lex) of the different MPcs. They observed that the short circuit current (JSC) is linearly dependent on the μh of the MPcs, except for ZnPc. They also estimated the Lex of the MPcs by creating a line of best fit using the action spectra of the external quantum efficiency in the solar cells and found that JSC is closely correlated with the Lex of the MPcs.

Click for Details (PDF 1.6 MB)
in English

5.Influence of the Triboelectric Charge of the Phosphor for PDP on Discharging Characteristic.

Yukihiko Sugio, Yo Hibino, Toshihiro Komaki

Summary

It is known that the discharge characteristic on PDP varies with the Phosphor of the RGB. In order to realize both high performance and long life on PDP, there is a need to control and increase the uniformity of the Phosphor of RGB, but evaluation of the discharge characteristic is also required to produce the panel and carry out electric appraisal, thus evaluating many Phosphors was difficult. Therefore, we paid special attention to electrification quantity on the Phosphor and examined the relationship with discharge characteristic on the PDP. As a result, we found out that the two were deeply related and succeeded in achieving uniform discharging voltage on RGB by controlling the triboelectric charge.

Click for Details (PDF 660 KB)
in Japanese

6.Spacer Layer Formation for Multi-Layer Optical Disk by UV-LED Arrays

Atsushi Kondo, Takao Tagiri, Masao Yoshimoto, Yasunobu Higashika, Seiro Ohshima, Toshihiko Takishita, *Osamu Yamanaka,(*Touhoku Pioneer)

Summary

On the multi-layer disk,very high accuracy is demanded from the thickness distribution of the spacer layer. We developed the new spacer layer formation method with UV-LED arrays in cooperation with the Tohoku Pioneer. By using the spacer layer formation method developed this time,it is possible to make the thickness distribution of the spacer layer over the whole disc within 2μm peak to peak. Thereby, it becomes possible to form a spacer layer of BD dual layer disc or BD multi layer disc as well as DVD-R dual layer disc.

Click for Details (PDF 1.9 MB)
in Japanese

7.Low-Noise and Low-Environmental-Impact Reflective Material for High-Density Optical Data Storage

Takanobu Higuchi, Yasuo Hosoda

Summary

We designed a new reflective material for high-density optical data storage that considers both recording and reproducing properties, and environmental impact. In order to improve disk noise, we tried to reduce the size of the crystal grains of the reflective layer by adding some elements that obstruct the growth of the grains. All elements of the reflective layer did not contain any substances specified by the PRTR law. We have developed a new alloy of AlPdSnO having a small grain size. When the new alloy was applied in the BD-type disk media, recording and reproducing properties were improved compared with the conventional aluminum alloy of AlTi.

Click for Details (PDF 1.5 MB)
in Japanese

8.Development of multiple-wavelength laser diodes for BD / DVD / CD compatibility

Mamoru Miyachi, Yoshinori Kimura, Yasuhiro Mimura, Atsushi Onoe

Summary

We developed a wafer-level integration process for multiple-wavelength laser diodes. This integration process allows highly accurate and proximal alignment of emission spots, as well as high mass-productivity. Using this process, we fabricated red/infrared two-wavelength laser diodes. In the two-wavelength laser diodes, the distance between two emission spots was approximately 3 μm. Furthermore we fabricated blue/red/infrared three-wavelength laser diodes whose emission spots were aligned within 10 μm distance. Such a short spot distance allows the optical components of the pickup to be substantially simplified.

Click for Details (PDF 1 MB)
in Japanese

9.Fabrication of active-matrix HEED(high-efficiency electron emission device) and its application to high-sensitivity image sensing

Tomonari Nakada, Takanobu Sato, Yohei Matsuba, Ryota Tanaka, Kazuto Sakemura, Nobuyasu Negishi, Yoshiyuki Okuda, Atsushi Watanabe, Takamasa Yoshikawa, Kiyohide Ogasawara

Abstract

HEED (High-efficiency Electron Emission Device) has various potential, and it is expected to be applied to ultrahigh-sensitivity image sensors. We developed an active-matrix HEED, and prototyped a HEED image sensor with a HARP (High-gain Avalanche Rushing Amorphous Photoconductor) target. The prototyped HEED image sensor with HARP has shown favourable characteristics of image sensing.

Click for Details (PDF 1.7 MB)
in Japanese

10.Nano-fabrication of LiNbO3 by focused ion beam for novel photonic devices

Xijun Li, Atsushi Watanabe

Abstract

Novel and high performance photonic devices benefited from nanofabrication attract more and more research interests. By applying already matured top-down nanofabrication techniques for silicon on insulator (SOI), photonic crystal slabs(1) and photonic wires(2) can be well fabricated. In this paper, we will report our recent progresses of applying focused ion beam (FIB) to engineering thin LiNbO3 (LN) layer on silica (LNoI), for which no mature nanofabrication techniques are available. In addition to successfully fabricated photonic crystal (PhC) structures, we also succeeded in directly patterning ferroelectric domains at sub-micro scale in LN ridge waveguide. Both integrated nonlinear optical devices and highly integrated optical circuits in LN PhC are also presented.

Click for Details (PDF 2.4 MB)
in English

[General Paper]
Song Surfing: Music playback system to explore a music library through similar-sounding phrases

Naoaki Horiuchi, Toshiyuki Sonoda, Koji Tanaka, Junichi Tanaka, Hideya Nagasawa, Shinichi Gayama

Summary

It has become relatively easy to construct a huge music library, but the existing interfaces for searching do not allow the user to fully enjoy the variety of songs in the library. Generally, the bigger the library is, the harder it becomes to select songs. In this paper, we describe Song Surfing, a new inter face for a huge music library. First, we explain how our system analyzes songs. Second, we present the system to explore a music library through similar-sounding phrases. Finally, we discuss the usability of this system thorough an experiment with a library of 300 songs. Song Surfing allows exploration of the library regardless of its scale.

Click for Details (PDF 1.2 MB)
in Japanese

[Introduction of Pioneer Group related R&D]
Introduction to the Devices Research Center

Fumihiko Yokogawa

Summary

The Devices research Center (DRC) was established in Corporate R&D labs in July, 2006. Our original devices and the systems using them, such as a new optical disc system, organic EL display, HEED, Ferroelectric probe memory, are developed in DRC. The author explains the mission and the research scope of DRC.

Click for Details (PDF 2.2 MB)
in Japanese

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