Our Strengths

2008Research papers

VOL.18 NO.1 Special Issue on AV & Communication Technologies

Index

VOL.18 NO.2

VOL.18 NO.2 Special Issue on Production Technology

Index

General Paper

Introduction of Pioneer Group related R&D

1．A Study of Audio Equipment Evaluations Using Time-Frequency Analysis

Toshikazu Yoshimi, Shunsuke Ishimitu

Summary

In evaluating the reproduced sound quality of sound systems, more weight should be given to the subjective evaluation by jury listening test. However an objective evaluation using physical measurements is also important.
Music makes a great impression on those who listen to it. If we have some objective measurement data corresponding to this impression, it will be comparatively easy to start to improve the sound quality performance.
In this report, we focused on a "dynamic" evaluation technique using a time-frequency characteristic of a response signal for the listening musical sound, instead of "static "evaluation for sine waves, and introduced SD method to sound quality evaluation of a commercial audio amplifier.
In addition, we also applied a similar technique in sound quality evaluation for aluminum electrolytic capacitors.
Furthermore, as an example of another application, the switch button sounds of a car audio system was adopted.

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in Japanese

2．A Method for Estimating the Direction of Sound Image Localization for Designing a Virtual Sound Image Localization Control System

Yoshiki Ohta, Kensaku Obata

Summary

We developed a method for estimating the direction of a sound image from the sound pressure distribution around a listening position. In the experiment, band noises that only differ in phase were produced from two Loudspeakers. We then examined the relation between the subjective direction of the sound image localization and the objective sound pressure distribution around a listening position. We found that an azimuth of localization can be expressed as a linear combination of sound pressure levels around a listening position. Our method can be used to estimate the azimuth with a high degree of accuracy and to associate the phase difference with the azimuth. Therefore, it can be used to design a virtual sound image localization control system.

Click for Details (PDF 1.2 MB)
in Japanese

3．Analysis of the Sound Field within a Car through the Boundary Element Method and Measurement

Tomomi Hasegawa, Yoshitomo Imanishi

Summary

To improve the design of the sound field within a car through simulation, we have investigated the accuracy of boundary element method analysis by comparing analysis results to measurements. First, through a simplified model, we examined how to treat the walls, seats and floor carpets in a car interior. Next, we have analyzed a full-size car with seats and floor carpets, and we report on the comparison of the simulation results to measurements and problems that we encountered when applying the simulation results to an actual car design.

Click for Details (PDF 3.2 MB)
in Japanese

4．Development of TAD Reference One

Shunichi Takahashi, Takanobu Saito

Summary

The TAD Reference One was developed for TAD's home speaker brand. Using the Coherent Sound Transducer (CST), consisting of a beryllium midrange cone and tweeter dome configured concentrically, this driver radiates both upper and critical mid-frequencies from a single point source covering an unprecedented frequency range from 250 Hz to 100 kHz. This results in accurate imaging and a seamless soundstage.
Furthermore, dual Tri-laminate Bass drivers with improved magnet circuit linearity and a cabinet finished in high-gloss piano lacquer were adopted for this speaker.

Click for Details (PDF 2.6 MB)
in Japanese

5．Attempt for High Luminous Efficacy PDPs

Masataka Uchidoi

Summary

In this paper, high luminous efficacy and very low black luminance ASSC (Address Space Separation Cell) Structure, which was reported in IDW `06 (The 13th International Display Workshop) (1), is reviewed.
PDPs are the displays using gas discharge. In a PDP each pixel is formed by three subpixels (cells or discharge cells) emitting red, green or blue primary color. For conventional cell structures, control discharges, which determine the on-off condition of the cell, and sustain discharges, which induce light output, are occurred in each discharge cell. For ASSC structure, each discharge cell is divided to two sub-cells of a control cell and a display cell. The structure of display cell is optimized for high luminous efficacy and the structure of control cell is optimized for discharge control (high speed and stable driving). ASSC structure shows high luminous efficacy, and high speed and stable operation of PDPs. In addition, low black luminance is also obtained by shading the control cells behind black stripes, where control discharges with unnecessary light emission are occurred. A test 50-in. WXGA ASSC PDPs shows a luminous efficacy of 2.8 lm/W, a panel peak luminance of 1,200 cd/m2, a black luminance of 0.04 cd/m2, and a contrast ratio of 30,000 to 1.

Click for Details (PDF 1.4 MB)
in Japanese

6．Web-Based Retrieval System for Product Operation Manuals Based on Knowledge Database Architecture

Takahiro Kamada, Masayo Kaji, Naoaki Horiuchi

Summary

Consumer electronic products have equipped much more functionalities than ever before, so that the volume of their operation manuals has kept on increasing, and that leads to a serious problem that it is becoming harder for users to utilize the manuals for acquiring information that they need. Therefore, we developed a Web-based retrieval system for product operation manuals taking advantage of knowledge database architecture. The knowledge database comprises a hierarchy structure of content description in the manuals and a variety of terms that had a similar meaning to some specific words included in the contents. We expected this system would allow users to get desirable information from the manuals more effectively, only by indicating keywords they could come up with easily.

Click for Details (PDF 1.6 MB)
in Japanese

7．Outline of the digital distribution of DVD-Video contents using CSS Managed Recording

Akira Shimizu

Summary

We have developed new CSS-contents-recordable DVD media for playback on DVD players and the recording system for such. We also have proposed a new disc format using these technologies at DVD Forum. They have been approved as "DVD-R for General Optional Specifications :DVD-Download Disc for CSS Managed Recording ,Part1 Physical specifications,Part2 File System specifications" in February 2007.
This format makes it possible, to distribute DVD-Video contents over the WEB , to record them encrypted with CSS, and to playback on the majority of the all consumer DVD players spread throughout the world because the recorded format is fully compatible with the DVD-Video format.
This paper is described for an outline of the digital distribution of DVD-Video contents encrypted with CSS, more specifically about the structure of DVD-DOWNLOAD disc and methods of CSS Managed Recording.

Click for Details (PDF 1.1 MB)
in Japanese

8．Development of "SmartLoop"

Masaru Sasaki, Toshiyuki Murata, Hiroyuki Kaizu, Kenji Takeda

Summary

We developed the "Smart Loop" function for our car navigation system. It allows users to generate the most suitable route based on constantly changing traffic congestion information regularly delivered regularly over a mobile phone network
"Real-time Probe" data on actual driving conditions is collected via the user's mobile phone and stored in the Smart Loop server. "Off-line Probe" information, which includes the user's driving history and "Auto-parking Memory" is accumulated in the system's "Brain Unit" to be downloaded from the user's "Living Kit" at their home through a broadband connection..
The "Smart Loop" function uses the information from the "Real-time Probe" and the "Off-line Probe", along with data from on demand VICS to provide the user with the most accurate data on traffic congestion to allow a more accurate estimate of their arrival time and the most efficient route to their destination.

Click for Details (PDF 896 KB)
in Japanese

9．Recent topics in surround sound audio

Masaki Sawaguchi

Summary

This paper will describe the recent trends in surround sound system based on the results of various investigations on this topic. According to those investigation results, our theoretical analysis of surround sound and the development of the method of reproducing it has been completed. To encourage the use of surround sound systems by many users, the development of contents that effectively reproduce the surround sound is necessary.

Click for Details (PDF 3.3 MB)
in Japanese

1．Optimization of the glass cleaning process and research of function evaluation

Takayuki Ishihara, Osamu Kumasaka

Summary

A parametric design was performed for the cleaning of glass plates, whose importance has been increasing because of the trend towards high definition in PDPs. The Quality Engineering method, using a noise factor to represent contaminations and seven controllable factors as parameters, was applied to provide significantly improved conditions both for less variation and better cleanliness.
The advantage of the Quality Engineering SN ratio was clarified by comparing between seven ways of human sensing transformed into a numerical value for cleanliness.

Click for Details (PDF 1.4 MB)
in Japanese

2．PDP rib forming optimization with Quality Engineering

Masanobu Itaya, Osamu Kumasaka

Summary

The conditions for sandblasting used in PDP (Plazma Display Panel) rib forming were studied and optimized by means of the Quality Engineering Method both in dynamic and statistic analysis. A set of sandblast parameters, which gives stability free from process variation effects and allows independent width control of the rib top and bottom, was found.

Click for Details (PDF 1.2 MB)
in Japanese

3．High-density mount mass production of PCBs by the FR -1

Toshiaki Yoshino

Summary

We have used  FR -4 (Woven glass and epoxy) in the main PCB for  DVD drivers up to now.  To improve the competitive price of our products, it is necessary to use FR -1 (Phenolic cotton paper) which is cheaper than FR -4. However, the precision of dimensions with FR -1 is worse than that of FR -4. Thus, to maintain the same quality of precision using FR -1 as when using FR -4 in mass production, we examined the relationship between the quality of FR -1 and the tolerance range of the precision of dimensions of FR -1. As a result, we could achieve the precision of FR -1 that was capable of mass-production in high quality.

Click for Details (PDF 6.3 MB)
in Japanese

4．Introduction of new soldering process using Flat-Dip

Mitsuhiro Matsumoto, Yousuke Arai

Summary

To mount parts up to 11 mm in height on both sides of PCB in our OEM (Original Equipment Manufacturing) products, we introduced a new soldering process which is Flat-Dip Soldering. Our old soldering process suffered deterioration in the quality of the product when mounting the parts with height in excess of 4.5 mm on it.
Then we examined soldering processes such as Flat-Dip, Diagonal-Dip, Small-Dip, Soldering Robot, that are able to mount parts up to 11mm in height on the PCB. As a result, we decided upon Flat-Dip which has the advantage of reliability in mass production.
To mass-produce with stability using this process, we measured heating temperature, flux spreading, and the relationship between the solder jet flow and the temperature, which are the important factors that influence the quality of the product using this process.
We improved these factors based on the measurement results, so that we achieved a defective rate for initial mass production by 0.003%.

Click for Details (PDF 1.4 MB)
in Japanese

5．Converting weather data obtained from the Japan Meteorological Agency into estimates of temperature and humidity in the car in which our product was actually used

Norio Isono

Summary

To sell products such as high-quality car audio and car navigations all over the world, we should do development, design, and reliability test of them in consideration of the temperature and the humidity of the various regions in the world where they are used.
Thus we constructed an original data base which includes weather data such as the temperature, the humidity, presence of dew and static electricity in order to supply these data to be useful for setting the condition of the reliability tests of products or analyzing problems reported in products. Moreover it contains the location data on a map where the products are used and the weather data that depends on the geographical features of each region.
The construction of the database was achieved by converting weather data of 1920 regions of the world, obtained from Japan Meteorological Agency, into the lowest temperature-2σ, highest temperature +2σ, and the average humidity of each location.
In addition, we estimated data such as lowest temperature and the humidity in the car for which our product was actually used using this database. As a result, the estimates were able to be applied to setting the examination conditions of products and the analysis of failures of the products.

Click for Details (PDF 1.7 MB)
in Japanese

6．Evaluation of a system for the analysis of the generation mechanism of PCB warping in reflow soldering

Seiji Matsunaga, Hisashi Mamizuka

Summary

Recently, there is a tendency for SMT (surface mount technology) of PCB(printed circuit board) to use reflow soldering due to multilayer, miniaturizing and high mounting density requirements. On the other hand, SMT defects in reflow soldering occur due to PCB warping, which is caused by the high temperature required because lead-free solder is used.
To examine this, we developed " SMT Defects Detection System by Measurement" which is able to detect SMT defects, and confirmed its high ability of detection through actual use. In this method, there are some troubles such as the delay of the product introduction and increasing the production total cost because the pattern of PCB might have to be redesigned when SMT defects is discovered.
To prevent this trouble, we examined whether it was possible to design the pattern of PCB using simulation so that SMT defects should not occur even if PCB warping occurs in reflow soldering. Then, we analyzed the generation mechanism of PCB warping using finite element modeling for simulation and setting the heating temperature to be 240℃ as the simulation condition for reflow soldering .
We analyzed the generation mechanism of PCB warping using " SMT Defects Detection System by Measurement " in order to evaluate the analyzed simulation results, and understood that both results are almost the same by comparing them.
As a result, we proved that the analysis of the generation mechanism of PCB warping by simulation was an effective method to prevent SMT defects in reflow soldering.

Click for Details (PDF 3.7 MB)
in Japanese

[General Paper]
Development of PDP Discharge Simulator

Noboru Minagawa, Hiroyuki Abe

Summary

We have developed a 3-D PDP discharge simulator to analyze the behavior of the discharge phenomena in a PDP cell, and to help us to design the optimum cell structures and optimum driving methods. This simulator can calculate space and time variations of many quantities in a PDP cell, which are difficult to observe experimentally. It enables us to understand the discharge phenomena in a PDP cell theoretically. This simulator can also calculate various characteristics of a PDP cell, e.g., wall voltage transfer curve, range of operating voltage, energy balance, UV efficiency, etc.
Calculation results of this simulator have matched well with the known facts and experimental results; thus we have confirmed the validity of this simulator. It will be a powerful designing tool for high definition and high efficiency PDP cells.

Click for Details (PDF 2.2 MB)
in Japanese

[Introduction of Pioneer Group related R&D]
Introduction to Towada Pioneer Corporation

Mitsuyoshi Shimamura

Summary

Towada Pioneer Corporation is a manufacturing subsidiary in Pioneer Group.
We achieved Q1 Award based on our performance in quality and delivery of a Ford Navigation System in February 2008. Furthermore, we achieved a VM Award for our 5S/VM activity that has been ongoing for three years. Our production innovation activity based on that activity was highly evaluated to the extent that we could receive the Pioneer President's Award. This article introduces Towada Pioneer Corporation through these activities.

Click for Details (PDF 5.8 MB)
in Japanese

Introduction to the Factory Automation Business Unit of Tohoku Pioneer Corporation

Toshitaka Horii

Summary

Tohoku Pioneer Corp. is one of the group enterprises of Pioneer Corp. and is composed of six departments, Speaker Business Unit, Mechatronics Business Unit, OLED Business Unit, Die and Component Business Unit, Corporate R&D Center and Factory Automation Business Unit.
This document describes the outline of Factory Automation Business Unit which includes basic principles, production methods and technology involved in the production.

Click for Details (PDF 1.5 MB)
in Japanese

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