R&D Spirits
Aiming for Top Visual Inspection Equipment
through One-of-a-kind Technology
Masakatsu Nunotani
General Manager
Vision System Division
NTT FANET Systems Corporation“Let’s move beyond desk-top science and develop original technology for on-site use to makereal contributions to the business world.” This is the R&D policy of Masakatsu Nunotani, general manager of the Vision System Division of NTT FANET Systems Corporation. The spirit
embodied by this policy is giving birth to new image-sensing techniques and visual inspection
equipment that are building a solid reputation in the business world. We sat down with Mr.
Nunotani to hear about the technical features and future outlook of this visual inspection equipment and to ask him about his personal beliefs and goals as an engineer.

From telephone card inspection to generalpurpose visual inspection equipment

led to my role as general manager of the Vision System Division at FANET.

—Mr. Nunotani, could you give us an outline of NTT
FANET Systems and tell us about your role there?

—What kind of business is the Vision System Division
involved in?

I would be happy to. NTT FANET* was founded in
1987 with the aim of applying technology developed
by NTT Laboratories to the manufacturing industry.
At that time, the “convergence of factory automationand network communication” was a popular theme,
and the name “FANET” was formed from letters inthose words. Then, in 1990, FANET obtained control
of printed telephone-card inspection technology
developed by NTT Laboratories, and this marked the
beginning of its vision systems business. This wasfollowed by a period of expansion into other businessareas including video systems, security equipment,
and environmental equipment. More recently,
FANET has built up a solutions business in partnership with NTT Communications, its top parent company. As for myself, my involvement with the development and implementation of printed card inspection technology during my days at NTT Laboratories

In short, I would say that we provide product-oriented visual inspection equipment based on image
sensing and processing. In the past, visual inspectionof printed matter such as telephone cards, printed
wiring boards, and various types of packages was
performed by the naked eye. The inspectors performing this work were highly skilled and capable, but thesimple fact that they were human meant that some
defects would go unnoticed and that dispersion in
inspection results could not be helped. Against thisbackground, the automation of inspection processes
is a major issue with manufacturers because of its
connection to quality and cost, and the equipmentthat we provide addresses this issue.
Our business can be broadly divided into three user
categories in terms of inspection targets (Fig. 1). The
first is general printing companies where inspection
targets are telephone cards (our first inspection business) and various types of cards, labels, and seals, aswell as pre-assembled packages called “blanks” forcosmetic and pharmaceutical products. The second is* http://www.ntt.co.jp/gnavi_e/com/83.html

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Lightning equipment

Cards andblanksPrinted wiringboardsTubes, bottles,
and caps

Line-sensor camera

Inspection target (bottle)

Captured image on display terminal(expanded image of all sides)

Fig. 1. Examples of inspection targets.

Fig. 2. Capturing images using a line-sensor camera.

electronic-component manufacturers where inspection targets are printed wiring boards (bare boards),
ceramic parts, display panels, connectors, and thelike. Much of our effort here focuses on the inspection of bare boards and IC-mounting boards that suffer from fine defects such as smudges, scratches, andomissions on the order of a few tens of micrometers.
In this area, we developed the industry’s first equipment to fully automate visual inspection that has traditionally been done by the naked eye. The third user
category is container manufacturers where inspection
targets are solid objects with nearly cylindricalshapes such as tubes, bottles, cans, cups, and caps.
This field has been growing dramatically in recent
years, and we are proud of our dominant share in themarket for inspecting aluminum and plastic tubes forpharmaceutical products and foods where other companies cannot approach our quality.

tion targets (Fig. 2). When inspecting a solid with acurved surface like a tube using an ordinary camera,
the image becomes increasingly oblique as the distance from the front view increases resulting in ahighly shrinked image with uneven lighting. In contrast, a line-sensor camera captures images by scanning only the front surface of an inspection target in a
linear manner while rotating the target. One complete
rotation gives us a stable and continuous expanded
image. On the other hand, a line-sensor camera isincapable of providing a completely undistorted
image since inspection targets are not limited to flat
objects and those with perfectly cylindrical shapes.
Even if high-precision imaging can be performed,that distortion will prevent captured images frombeing compared with registered reference images.
This is because image distortion itself will be treatedas a defect with the result that all inspected items are
judged defective. To deal with this problem, wedeveloped a new image-alignment technique called
line-block distortion reduction (Fig. 3). As the nameimplies, this technique divides an input image into a
number of line blocks and overlaps and shifts thoseblocks as needed until they approach the reference
image. The resulting image can now be comparedwith the reference image and any smudges or character imperfections that are found can be judged as
defects. The idea here is to perfectly align the twopatterns so that extremely small differences between
them can be discovered. This technique can detectproblems as small as fine character defects that could
not be found with past equipment or by the naked eye.

—Please tell us something about the technology
behind this visual inspection equipment.
The basic mechanism of visual inspection is patternmatching. The idea here is to compare images of thetarget item with reference images of a good productto detect differences between them. In actual inspection, though, a certain range of dispersion appears in
inspection results, and we must allow for that dispersion. For this reason, we add a learning capability
using multiple registration of several reference
images.
We also use a line-sensor camera to shoot inspecVol. 2 No. 9 Sep. 2004

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R&D Spirits

Horizontal scanLine block

Vertical scan

B
Registered reference image

B
Input image with distortion

Distortion-free image afterreconstruction of line blocks

Fig. 3. Line-block distortion reduction method for pattern-matching inspection.

FANET has already obtained foreign patents for thistechnology in the United States, United Kingdom,
and Europe. You might say that we hold a nearly
global monopoly on this technology.

Development of next-generation equipment
along two directions—What benefits does FANET visual inspection technology bring to users?
Well, first and foremost would be reduced labor andimproved quality, the immediate objectives of ourtechnology. But it will also contribute to improvements in manufacturing processes through the appropriate application of inspection data. Take, for example, pharmaceutical products provided in aluminum
tubes. The usage, dosage, ingredients, and otherinformation about a product are often written in fineprint. The inclusion of this information is prescribedby Japan’s Pharmaceutical Affairs Law, and the presence of smudges or character defects that could prevent that information from being read or properly
understood would be a serious matter. As I mentioned
earlier, FANET equipment can inspect this fine print
automatically. In this field, FANET’s visual inspection equipment is becoming a de facto standard due tothe demand for it from manufacturers of pharmaceutical products. Needless to say, industry’s recognitionof our technology gives us a great feeling of achievement.
I should also point out that the manufacture of containers for pharmaceutical products and foods is performed for the most part in clean rooms, which meansthat the use of human hands in visual inspection, the8last step in this process, presents a problem from ahygienic point of view. How to remove the humanelement from clean rooms has been a major issue for
manufacturers. Our equipment, which completely
automates visual inspection, is playing a role inachieving that goal. Conventional naked-eye inspection, moreover, could do no more than observe—it
was not capable of saving inspection data. Automated inspection, on the other hand, can save all dataobtained in the inspection process. This provides ahigh level of traceability that, in the event of a customer claim, enables container manufacturers tomake a clear determination as to whether they are toblame and to respond accordingly. Such data can also
produce an immediate improvement in manufacturing yield. I think those inspection database is a great
benefit to users.
—What are the R&D trends in this area, both inJapan and overseas?
To begin with, there are many competitors. In theprinting and container field, I would say that Japanese manufacturers of visual inspection equipment areat the forefront, while in the electronic-components
field, many overseas manufacturers have dominantpositions. But a manufacturer like FANET that cancover all fields with just one type of equipment israre. We also dominate the Japanese market for
inspection of aluminum tubes and are working on
overseas deals. We are confident in our ability to
become a world leader in this area. At the same time,
we are in an era of competition with an abundance of
players ranging from long-established companies to
new ventures, so we must continue to innovate and
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evolve in order to survive. I must admit that trends inother companies are a bit disturbing, but our plan is todevelop original technology one step ahead of ourcompetitors by identifying and meeting needs basedon current and relevant user information. In this way,
we aim to stay a one-of-a-kind company in this industry.
—What direction will future strategy and development take?
Our current machine embodies the second generation of our technology. The first-generation machineused color processing to inspect mainly flat objects
like cards, while the second-generation machine caninspect solid objects. Compared with the firstmachine, the current machine has four times the processing speed, occupies one-fourth the volume, andcosts half as much. The second-generation machine,
however, provides monochrome processing as standard, which is a disadvantage in the face of competitors that provide color processing. Of course, color
processing is available as an option, but because
inspection performance is already high to begin with,the second-generation machine can perform inspections at required levels without having to use color.
Nevertheless, it is obvious that our competitors aremaking progress, and based on our strategy of staying
one step ahead before falling behind, we plan toincorporate color processing as standard in our thirdgeneration machine. This machine will have 16 times
or more image-processing capacity, 2.5 times more
processing speed, and one-fourth the volume.
In addition, our third-generation development
efforts are proceeding along two directions. The firstis high-end oriented as in the machine I just mentioned. This is a super machine that performs image
processing by dedicated hardware, all of which wasdeveloped in-house. The machine has been three
years in development and its release has begun. The
other direction will be low-cost while achieving functions and performance equal to that of the current
machine by software means. This machine will use ageneral-purpose PC with a high-speed CPU and feature software processing that can flexibly apply avariety of inspection algorithms accumulated as
inspection know-how over the years. The idea here isto provide a “popular model” that can find widespread use in the industry. Our lineup will therefore
consist of a high-end product in a class of its own anda popular product having good cost-performance. My
problem from here on is to figure out how best toVol. 2 No. 9 Sep. 2004

market these two models.

R&D origins: The joy of creating—Mr. Nunotani, how did you get started in R&D?
I have always been absorbed in building something.
In my childhood, it was models, as a junior-highschool student, it was radios, and as a high-school
student, it was audio equipment. Being this kind of
person, I entered electronic engineering studies without hesitation and with many expectations. But after
beginning my studies, I found that courses on electromagnetism and quantum theory with their many
formulas could be quite stressful. While I can be very
enthusiastic about subjects that I like and am interested in, my character is such that I can also be less thandiligent with regard to subjects that don’t particularlyinterest me. To be more specific, I find that I canquickly understand the nature of phenomena that canbe seen with the naked eye or that can be represented
visually. It is this kind of phenomena that excites myinterest and stimulates my creative powers. The
image-sensing world that I am currently in energizes
me. In this world, I can create something using thescientific and mathematical knowledge and generalknowledge I obtained in school plus a small amountof specialized knowledge. At any rate, my thoughts
throughout my days as a college student were that I
wanted to get to work as soon as possible and feel thejoy of creating. These were the origins of my current
R&D activities, and my feelings in this regard havenot changed one bit since then.
—What kind of R&D were you involved in at NTT
Laboratories?
After entering NTT Laboratories, I became
engaged in the research and development of memory
devices and electronic circuits related to magnetic
wire and magnetic bubbles. Although magnetic bubble memory was initially a hot topic, it was a “phantom memory” that would soon be replaced by IC
memory. I was a member of the group that developed
equipment at NTT that came to implement this typeof memory. At that time, NTT possessed portablemechanical telephone switches that could be loaded
onto a truck to support communications at times ofdisasters, and there was a need to replace thesemechanical switches with electronic ones. Magnetic
drums were then being used in electronic switches,
but they were too vulnerable to vibration to be used in9

R&D Spirits

mobile equipment. For this reason, we decided toreplace the magnetic drum with a solid-state magnetic bubble memory that was robust to vibration. Thismagnetic bubble memory was later adopted in highperformance electronic switches as well, and consequently this research obtained the NTT President’s
Prize. Even today, quite a number of magnetic bubble
memories are still in operation at NTT sites.
After that project, I became involved in the development of high-capacity storage systems as a systemdesigner. At that time, integrated magnetic-tape systems were being adopted as backup systems for general-purpose mainframe computer systems.
—How did you become involved with your present
line of work?
As we entered the 1990s, personal computers anddistributed processing technology had advanced tosuch a level that NTT began to wind down its computer development work. While wondering what I
could do next, I heard talk about building image processing equipment. This was the printing inspection
equipment for telephone cards. The world of image
processing that makes use of hardware technology
was a field where I could apply my specialized
knowledge and that attracted my interest. The development of this equipment would also require not justimage processing technology but also an odd assortment of peripheral technologies such as pick-up
devices, lighting, mechanical mechanisms, and algorithms. That was exactly the type of development that
I was experienced in. As a result of my interest, I wasplaced in charge of implementing the equipment andperforming subsequent follow-ups. It took two years
to complete equipment development, and in 1993, I
was transferred to FANET with the task of turning
this equipment into a full-scale business. I have beenat FANET ever since.
—How do you view your work at FANET?
I look upon it as an “intelligent sport!” In a worldthat demands creativity, competing with a rival on thebasis of technology and intelligence can be highly
stimulating to an engineer’s spirit. In addition, it is
the customer who decides the winner, which is fairenough. Furthermore, as obtained profits can be treated as a gauge of equipment value, there is a way toquantitatively measure results. This work gives memuch satisfaction.

10“Fountain of knowledge”—Giving purposeto an engineer’s life
—Mr. Nunotani, how will your work develop fromhere on?
Visual equipment is expected to see continued
growth in the years to come. In particular, the global
production of containers is growing and quality
requirements are becoming stiffer. One issue that I
will have to face here is how to deal with the wide
assortment of container shapes. And in the field ofelectronic components, we can expect the need forvisual inspection of printed wiring boards and flat
panel displays to increase, and this is also somethingthat I would like to pursue. Furthermore, from theviewpoint of developing an even wider market, I can
see us cultivating new fields that can apply the technology developed in visual inspection. While we are
not yet at the stage of making specific proposals, weare interested in applying visual technologies like
image sensing and robot vision to a wide variety offields including security, the environment, and social
welfare.
—What are your personal aspirations at this time?
At NTT Laboratories, there is a pond called the“fountain of knowledge” where there used to be amemorial stone engraved with the words: “Let’s dip
from the fountain of knowledge and make it usefulfor the benefit of the world.” I noticed these words on
my first visit to NTT Laboratories before entering thecompany, and they have remained in my head eversince. I can relate strongly to these words that I
believe reflect the history of NTT Laboratories andmy own history as well. These are words that can give
purpose to an engineer’s career. For me, a lifelong
engineer, the practical application of these words
means to be active as long as possible while maintaining my curiosity, ambition, and competitiveness.
My wish is to continue building things based on a scientific approach, creative ideas, and a simple-isbeautiful concept and to achieve more “industry first”
commendations.
—How would you describe life at NTT Laboratories?
NTT Laboratories has been a place of learning forme in my journey to my present position. Throughvarious R&D projects spanning a period of 20 years,
I have learned much about implementation methods
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from my senior colleagues and manufacturing partners, especially in regards to research and implementation, equipment reliability, and quantitative evaluation. In addition, the various techniques that I was
exposed to at NTT Laboratories are the roots of myscientific approach. While this approach may not beapplicable to all on-site development, I am passing it
on to junior researchers as an ongoing guide for performing research work.
—Mr. Nunotani, could you leave us with a message
for NTT Laboratories and its researchers?
The pool of human resources at NTT Laboratories
is enormous. I would hope that this pool can beapplied to the extensive field of industry in addition
to the communications and education fields. The
achievements of NTT Laboratories accumulated overthe past several decades provide researchers with agreat source of potential products. I would like to see
those achievements made into something useful for
the world so that researchers can see the fruits of theirwork and feel a sense of purpose. I am convinced that
if mid-level and senior researchers, who have gainedmuch experience in their work, go out into the realworld, they will encounter a wealth of possibilities. I
ask all my fellow researchers to take on a fresh attitude and to step outside the traditional frameworkwith a view to the outside world. In this regard, I
think NTT’s “internal venture system” and “internal
recruitment system” are effective. Even FANET
includes personnel that have entered the company
through this internal recruitment system, and thesepeople work as if they have found their element. I
would be happy if our combined activities at FANET
could become a reference for creating a new stage in
research and development. Finally, I hope that NTT
as a major organization can back up this effort withall its strength.

Vol. 2 No. 9 Sep. 2004

Interviewee profile■ Career highlights
Masakatsu Nunotani received the B.S. and M.S.
degrees in electronic engineering from Osaka University, Osaka, Japan, in 1966 and 1968, respectively. He
joined the Electrical Communications Laboratories of
Nippon Telegraph and Telephone Public Corporation(now NTT) in 1968. He was engaged in R&D ofdevice, circuit, and system design for some kinds ofmagnetic memories (wires, cores, and bubbles) andmass-storage equipments (magnetic tape and opticaldisks). He was engaged in the development of memory equipment for NTT’s data processing system(DIPS) and switching system (DEX). He is currently
the general manager of the Vision System Division,
NTT FANET Systems Corporation. He developed
image-processing systems with an original architecture for visual inspection applications. His current
interests are image sensing and machine vision.

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