Oral-History:Heitaro Nakajima

About Heitaro Nakajima

Heitaro Nakajima

Heitaro Nakajima is a communications engineer best known for his work on digital recording at the NHK and at Sony Corporation. He received a bachelor's degree in electrical engineering from the Tokyo Institute of Technology in 1944, a masters' degree from Kyushu University, specializing in acoustics, and a Doctor of Engineering degree in 1958 from Kyushu University. After receiving his master's' degree, Nakajima went to work for NHK, working first at their Kyushu broadcasting station and then going to NHK's Setagaya research center, working in the acoustics department. After Nakajima received his doctoral degree, NHK promoted him to head of the transducer research department; in 1965 he became general manager of the acoustic research division; in 1968 he left the acoustics division; in 1968 he became general manager of the NHK's Broadcasting Science Research Laboratory. In 1971, under unusual circumstances, he left NHK and went to work at Sony Corporation, where he held research and business positions simultaneously. At Sony Nakajima pushed for digital audio research and was involved in Sony's partnership with Philips on the development of CD technology.

The interview begins with Nakajima's early interests in math and science and his education at the Tokyo Institute of Technology during World War II. He discusses his studies at Kyushu University and his early work on acoustics at NHK. He discusses the evolution of acoustic research and analog and digital audio recording as a result of broadcasting related to the 1964 Tokyo Olympics. He discusses the advantages and disadvantages of his position as general manager of NHK's Broadcasting Science Research Laboratory, and then discusses the unusual circumstances of his recruitment by Ibuka and Shima of Sony Corporation. He discusses his business and research positions at Sony, and treats the partnership between Philips/Polygram and Sony/CBS-Sony for digital audio research and development and the eventual development of the CD. The interview ends with Nakajima's emphasis on the need for insight and intuition in research and development work.

About the Interview

Heitaro Nakajima: An Interview Conducted by William Aspray, Center for the History of Electrical Engineering, May 24, 1994

Interview #207 for the Center for the History of Electrical Engineering

The Institute of Electrical and Electronics Engineers, Inc.

Copyright Statement

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Request for permission to quote for publication should be addressed to the IEEE History Center Oral History Program, IEEE History Center at Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030 USA. It should include identification of the specific passages to be quoted, anticipated use of the passages, and identification of the user.

It is recommended that this oral history be cited as follows:

Heitaro Nakjima, an oral history conducted in 1994 by William Aspray, IEEE History Center, Rutgers University, Hoboken, NJ, USA.

Interview

Interview: Nakajima, Heitaro

Interviewer: William Aspray

Date: 24th May 1994

Place: Sony, Tokyo

[Note: Nakajima's words were translated. For some replies Dr. Yuzo Takahashi of Tokyo University of Agriculture and Technology made extra comments.]

Family Background and Childhood

Aspray:

Could you begin by telling me where you were born, what your parents did, and where and when you were born?

Nakajima:

I was born in 1921. I am now 73. My parents were from Fukuroka on Kyushu Island, from a town called Kurume. They were merchants involved with rubber shoes in Japanese "Hakimono."

Aspray:

The production of shoes?

Nakajima:

And selling them.

Aspray:

Were any members of your family, brothers or sisters or grandparents, involved with engineering or science?

Nakajima:

My younger brother was involved in mechanical engineering. Unfortunately he passed away in his early twenties, at twenty-four or twenty-five.

Aspray:

When you were a boy, were you interested in doing things with your hands such as building radio sets or small motors, or doing chemical experiments?

Nakajima:

Yes, I certainly was interested. I was making radios when I was a child using the old coil-based radios. I was a rather weak child physically. Perhaps a third of my elementary school life I was absent from school because of illness. I didn't feel that I excelled in any way compared to other students.

Aspray:

Did you take an interest in mathematics and science work in your formal education, primary and secondary?

Nakajima:

I can definitely say that I was only interested in math and physics as a student. In other subjects, try as I might to remember things, I found it very difficult and was never able to succeed.

Aspray:

Was it expected that you would go to college?

Nakajima:

No, I don't think so. I think my parents' first expectation was that I would carry on the family business.

Aspray:

I see. What was it you wanted to do as opposed to what your parents wanted you to do as a child?

Nakajima:

I basically wanted to do a job that was involved in some way with mathematics or physics.

Aspray:

What effect did the war have on your coming career plans?

Nakajima:

I think it had a great influence.

Takahashi:

[He was afraid that he would be killed very easily. He thought that he would die because military service is a very hard job, and he was happy to remain in school and get a higher education.]

Tokyo Institute of Technology

Aspray:

How did you choose to go to the Tokyo Institute of Technology?

Nakajima:

I had to strike a fine balance because there were many subjects that I wasn't very good at in general education, although I was good at physics and math. As a result, I don't think I would have been able to enter Tokyo University. That wasn't an option. It just happened to be that Tokyo Institute offered a balance of subjects in their entrance exam that favored the subjects I was strongest in, and that's why I chose that university. It fitted that balance.

Aspray:

Which course of study did you choose to take?

Nakajima:

Electrical Engineering.

Aspray:

Why that instead of physics or mathematics?

Nakajima:

Those studies really weren't available at that time.

Aspray:

Because it was a technical institution?

Nakajima:

Exactly, yes. At that time they had no physics or mathematics departments.

Aspray:

Yes. Within electrical engineering, were there choices of programs, for example in power or communications? If so, which of those did you study?

Nakajima:

Telecommunications.

Aspray:

Did that include the study of radio?

Nakajima:

The study of radio weapons, weapons for the military.

Aspray:

I see, radio controlled...

Nakajima:

Yes. But since this was already wartime, the university laboratory had to serve the navy. It was a kind of radar, a searching radio wave.

Aspray:

Were you a good student in university?

Nakajima:

I was a lot stronger than when I was an elementary school student, so I did rather better at my studies and worked harder. I did a fair amount of playing as well during that time.

Aspray:

Were there particular members of the faculty who influenced your career at that time?

Nakajima:

Yes, there definitely were, two teachers in particular. One was Professor Yagi, who was the principal of the institute, the inventor of the Yagi antenna.

Aspray:

Very famous.

Nakajima:

Secondly, Professor Awaya. He was the professor of acoustics in the university.

Aspray:

When you graduated in 1944, what did you do?

Kyushu University

Nakajima:

At first I studied at the Morita research center of the Tokyo Institute of Technology and then went on to pursue my masters at Kyushu University.

Aspray:

Why did you choose to go to that university?

Nakajima:

Part of the reason was the difficulties associated with living in Tokyo just after the war. Kyushu was, in a sense, an easier option. I have always been aware of being rather weak physically, and of having to take great care of that. Once again this influenced my decision. Another reason was that there was an excellent professor at Kyushu University, in acoustics, and I wanted to study in that field. He was named Professor Mori.

Aspray:

Did you have to write a thesis for your master's degree, and if so, what was the subject?

Nakajima:

I didn't have to write a thesis for my master's. At that time I was involved in a form of military research concerned with Kanmon channel.

Takahashi:

[Kanmon channel is a location between Honshu and Kyushu.]

Aspray:

A communication channel?

Nakajima:

No, it's a physical channel, a narrow sea. They were conducting research into communications across it.

Takahashi:

[The research was in acoustics-sensing bombing, or something like that. Japan developed an acoustic weapons industry. The army or navy had to find a location to detonate the bomb. He helped in this work.]

Aspray:

I see.

Nakajima:

The year after that, the war was over and everybody was too keen on celebrating and enjoying themselves. The final result was that I didn't write a thesis.

Aspray:

Did you get a chance to study acoustics though, while you were at Kyushu?

Nakajima:

Yes. Straight after university I didn't have anything in particular to do, so I did a lot of reading in acoustics.

Joining (and Staying at) NHK

Aspray:

In 1947, when you joined NHK, how did that decision come about?

Nakajima:

At that time NHK had a policy of expanding its research in acoustics. They made me a sort of informal offer: "Wouldn't you like to join us and study here?" I wanted to pursue studies there, so that's how I entered.

Takahashi:

[At Kyushu University he was not home bred. A young fellow who had graduated from Kyushu University would have been in a better position to get a carrier at the university.]

Aspray:

You had to have done your bachelor's studies as well as your master's studies at the University to get a good position in the university?

Nakajima:

Yes.

Takahashi:

[He was a graduate of Tokyo Institute, therefore he thought he had better find a job position other than at the Kyushu University.]

Aspray:

In industry rather than in a university?

Takahashi:

[Rather than in Kyushu University.]

Aspray:

Rather than that particular university, yes. Did you consider positions at other companies?

Nakajima:

No, I didn't. If there had not been the offer from NHK, I think I would have remained at Kyushu.

Aspray:

Can you tell me about what you found at NHK when you arrived at the company? What kind of research and development operation did it have? How many people were there? What were they doing? What was its strategic value to the company?

Nakajima:

When I first entered NHK, they had asked me to join with the wish of expanding their acoustics department. I thought I would move to that particular area, in Tokyo, immediately, but in fact the first place they actually wanted to send me was to the Central Research Institute in Kyushu, in Kumanoto. They were working on audio mixers at that time, in that institute. It was an extremely primitive form of mixing. They were working on how to record a large number of people in one area, for example using one microphone.

Takahashi:

[In the field or the street. The NHK people wanted to record the opinion of the people on the street, as a form of democracy.]

Nakajima:

Well, obviously I was very disappointed with this state of affairs. Three days after I arrived my first child was born, and almost the next day I handed in my resignation. The head of the department persuaded me, "Well, you can't go back to Kyushu University, there's nothing for you there. You haven't achieved anything yet. You haven't done anything yet. Why don't you stay with us and try?" I was reluctant, but he persuaded me to stay. As it turned out, as I began to study and get on with the research, it became more and more interesting. At that time there were a number of people there, a lot of whom were working just in order to live. As a result of that, the level of research going on was not very high. But I gradually became more involved with the research and more interested in it. This influenced my decision to stay at the Kyushu broadcasting station. One of the big reasons was that if I didn't stay and try my best there, they wouldn't let me go someplace else in the near future!

Acoustics Work: Microphones

Aspray:

What was the larger constellation of research centers within NHK?

Nakajima:

At that time the research was only being conducted right at the center in Tokyo. In the other broadcasting departments, getting the sound and transmitting it was the day-to-day job. On the other hand, from Tokyo new devices were supplied and new ideas being fermented. In order to support that, the research center at Setagaya was acting as a support function for that sort of development. So one year later I entered the acoustics department of that research center.

Aspray:

In Tokyo?

Nakajima:

In Tokyo.

Aspray:

Was NHK doing all of its own research or was it contracting out work to other companies to develop broadcasting technology?

Nakajima:

Almost all the research was going on in-house. Looking at it from the other point of view, if NHK, for example, developed a new and very good microphone, then we would take it to a company like Sony for production.

Aspray:

How many different divisions were there in the Tokyo research laboratory?

Nakajima:

There were a variety of different departments. The main ones were acoustics, TV, wireless, and electron tubes. There was some other research going on, such as transmission, but those were the main departments.

Aspray:

Okay. What were the main problems being addressed in the acoustics department?

Nakajima:

There were about 25 or 30 people working there, divided into four groups of about six people each. One group was working on transducers and the development of acoustic materials. Another group was working on room acoustics. Psychoacoustics, I think we would call it now. I was working with the transducers group.

Aspray:

What in particular were your assignments?

Nakajima:

I first worked on directional condenser microphones.

Aspray:

Would you please trace the next few years of your career, in terms of positions you held, and in terms of your major technical problems and accomplishments?

Nakajima:

I was working on microphones principally for that period; one or two of us were working together. We were doing research that was also going on in parallel in other countries such as Germany. Particular problems we looked at were connected with materials, for example the use of membranes and developing effective insulating material for microphones. Those were the particular areas of concentration. Japan is affected by very big changes in atmospheric temperature and humidity. Solving the problems that that creates was one of the big projects in which I was involved.

Aspray:

Did this research bring successful solutions for these problems?

Nakajima:

Yes, we did achieve a certain success, particularly in the use of membranes, working in conjunction with the acoustic materials department.

Aspray:

These were actually put into practice at NHK for its broadcasting work?

Nakajima:

Yes, they were. I was involved in developing the microphones to a prototype stage, and then the next step was to take them to a company. Then they would go into production as products.

Takahashi:

[Sony produced the microphone.]

Nakajima:

In fact, that microphone C-38 turned out to be a long-time seller. Recently I saw it; the outside is completely different, but the internal structure remains pretty much the same as it was at that time.

Aspray:

This was your first direct professional relationship with Sony?

Nakajima:

Yes, that's right.

Doctorate from Kyushu

Aspray:

In 1958 you received your doctor of engineering degree from Kyushu. Did you do this while working for NHK, or did you take time off and go back to Kyushu to study?

Nakajima:

I didn't have to physically attend the university, just submit a thesis.

Aspray:

What was the reason for getting the degree? Was it valued by the company? Was there a belief that you would learn something additional by doing this?

Nakajima:

It certainly wasn't from any positive influence from the company. NHK's attitude could be described as negative. Obviously it is very different now. It was more of a personal wish. I had been writing several papers and thought that, if I could bring these together, I could submit them. This is what a professor at Kyushu University advised me. Although I had written papers before, I had never written them other than on a Saturday or a Sunday. To bind the copy of a thesis, he himself had to go to a small shop at Kanada: NHK gave him no support. Afterwards it changed, however, and the situation became better. The company's attitude then changed. They said, "If you are able to produce this kind of work and have time to do it, then you should be doing something more advanced within the company as well."

Aspray:

This was the start of your move into more responsible positions?

Nakajima:

Yes, in 1958 I was put in charge of one of the research departments, the transducer department. The overall research direction, the overall research into acoustics, was assigned to me in about 1964 or 1965.

Digital Sound Recording

Aspray:

This curriculum vitae says from 1965 to 1968 you were General Manager of the Acoustic Research Division. Had the nature of the problems being addressed in this department changed by that time?

Nakajima:

When I was general manager of the acoustics research department, I started to shift toward developing some form of digital sound recording.

Aspray:

What was the reason for this?

Nakajima:

In the 1964 Tokyo Olympics, they had a whole range of hardware to aid the broadcasting of that event, including microphones, speakers, and tape recorders. That came to an end, obviously, after the Olympics, so it was a case of, "Well, where should the next direction be? What's the next challenge we should be looking for?" At that time we strongly felt that FM broadcasting would become the main broadcasting form for sound, and as a result we wanted to look into forms of research studying the whole acoustic environment for FM broadcasting. At that time we started to conduct research onto the whole transmission process: from the studio, to the microphone, to the transmission itself, then to the receiver in the listener's home. We were looking into the whole system, and how to improve it.

During that research we established that the biggest influences on sound quality were two-fold. Firstly the master tape recorder, and secondly, the transmission itself. Of those two, we felt transmission was the province of NTT, something we should leave to them to work on. We therefore concentrated our efforts on the other element, the master tape recorder and the reduction of noise for the master tape recorder. We worked on the tape, on the powder of the tape, and on the film. We worked on the recording head. We also worked on the tape transport mechanism. While we had lots of small improvements, we didn't find anything that could be really counted as a major leap forward in sound quality.

Aspray:

These were still all analog tape recorders?

Nakajima:

Yes. We then turned our attention to the digital technology used in computers. The reason for that was our feeling that if it was already being used in that area, then it should represent very high reliability. The other thing going on then was long-distance digital transmission with a very high degree of success in terms of signal quality and signal density. Then we thought that if digital transmission offered that very high signal quality and reliability, surely these were elements we could bring to the realm of audio as well. One of the researchers suggested this and said, very strongly, "This is the way to go." That was accepted and was the path down which we progressed.

Aspray:

Was this intended to have short-term pay-off? The reason I ask the question is that, at least in the long term, it turned out that a lot of signal processing had to go on to use this digital technology, and this relied extensively on semiconductors. Semiconductors were in their infancy at this time and weren't really up to the demands of this technology. The question, therefore, is whether you felt you could get a short-term product given the state of semiconductors at that time?

Nakajima:

Did we already foresee the fact that it would entail long-term research in semiconductors?

Aspray:

Yes.

Nakajima:

It's a sort of combination of the two answers in a sense. No, we didn't realize there would be so much involved with digital signal processing, or that semiconductor technology would be such an essential part of it. On the other hand, we were aware that this would not produce short-term benefits. The reason for pursuing the research was that we had been making very little progress and felt some new direction was necessary in order to deliver any kind of successful development.

Aspray:

Can you describe the development of this research program? What successes did you have? What challenges did you have?

Nakajima:

The only materials we had to draw on were the technology from long-distance digital transmission and from digital techniques in computers. From that point on, we had to come up with everything ourselves. We used a one-inch video tape recorder and borrowed a huge D/A converter from Texas Instruments. With those as our basic materials, we worked for about two years. The result was that we came up with a huge rack digital tape recorder. Even the parts cost alone might have been five million yen. The price at the time was something like three times that of conventional professional recorders. It was too big, too heavy, and too difficult to use, but the sound was good. That was the one thing that could be said in its favor.

Aspray:

As a result of this first trial, did you decide to start to improve this?

Nakajima:

I certainly wanted to go on to the next stage and try to solve those problems. However, my bosses felt that those three bad points were too much, and they decided it was best to fade out the research in that area. I wanted to carry on with that research because when I heard the difference between digital sound and analog sound, it was as if somebody had removed a veil out of the way. It was a tremendously clear signal, a tremendously clear sound, and that was my reason for wanting to carry on. Against the background of these earlier small improvements, suddenly finding this way of drastically improving sound quality showed me we were definitely on to something. To promote that research, I enlisted the head of the acoustics department in trying to persuade the general manager to carry on the research. However, the popularization of color television was going on. The emphasis was on color television research, which won out.

Aspray:

What year was this?

Nakajima:

The sixties. This was in the period immediately following the Olympics, when Japan had its big boom in color television sales. That was the reason for this emphasis on color TV. At that time the feeling towards sound recording was, "That's fine. We can live with that." This was when I shifted to the Broadcasting Science Research Laboratory post.

Broadcasting Science Research Laboratory

Aspray:

You were still the General Manager of the Acoustic Research Division in this 1965 to 1968 period, according to this listing. It was at this point that you moved?

Nakajima:

When I shifted to my new post, it was very difficult for heirs to the throne, as it were, to carry on that promotion once I had effectively disappeared to another post.

Aspray:

Was the acoustic research division a unit of this larger Broadcasting Science Research Laboratory, or were they two different organizations?

Takahashi:

[At that time NHK had two research laboratories. One was the Technical Research Laboratory, and the second was the Broadcasting Science Research Laboratory. Dr. Nakajima was promoted to head of this Science Research Laboratory. Acoustic Division belonged to the Technical Laboratory.]

Aspray:

Can you tell me the directions of the research? What kinds of research were going on in the Broadcasting Science Research Laboratories?

Nakajima:

The Science Laboratory had two fields; the first was material science related to optics, and light, photoelectric and photomagnetic materials, optic science, and lasers. The second field was psychology and recognition, how the human body reacts to and detects light and sound.

Aspray:

Obviously the higher-level people in NHK felt that you were doing a good job, and you kept getting promotions within the company. Did you like being a manager?

Nakajima:

Yes, I was very happy because as General Manager I was more directly involved with the research and with the nuts and bolts. As I moved up, I was able to give direction to a wider number of people and that pleased me very much. Basically I had mixed feelings about being the director of the institution. On the one hand, the salary was not bad, and I had the advantages that go with a certain amount of power.

Aspray:

So there is a certain frustration with not being able to pursue these ideas and follow them through to a product. During the three years while you were director of the Broadcasting Science Research Laboratories, what were your greatest successes? How did you make a mark on the organization?

Nakajima:

Rather than any particular successes in research, what I seem to remember most is that this was an entirely new area with an entirely new culture. There was a tremendous range of research going on, and a tremendous range of fields. Managing the organization and dealing with that was possibly the biggest challenge. There were people from physics, materials research, chemistry, and engineering, medical research, psychology, as well as those and tending toward what we would call the humanities and arts side. Merely dealing with all of that was really the toughest challenge. When I look back on it, it was tremendously interesting, but it was tough. There were some animal experiments going on at the institute at that time, with brain surgery on cats, for example. I was involved in where to find the cats, and how to bring it to the research labs.

Aspray:

You were a very hands-on kind of person.

Nakajima:

As part of the director's job, I also had to deal with the animal rights people at the time. They checked on the experiments, and so on, following things through. This was all part of the director's responsibilities.

Joining Sony

Aspray:

You've told me about one contact you had with the Sony Corporation during this period. Did you have subsequent ones, either as General Manager of the Acoustics Division or as Director of the Broadcasting Science Research Laboratory?

Nakajima:

There were some technical contacts connected with microphones, and later with tape recorders.

Aspray:

In June 1971 you joined the Sony Corporation. Can you explain how this came about?

Nakajima:

At that time I can't say that I had any real desire to enter Sony. As director of the Broadcast Science Laboratories it wasn't the perfect environment, but there were many advantages to it, and an awful lot of opportunities for learning were to be had there as well. It was through the persuasion of people on the Sony side that this came about. Most urging was from Masaru Ibuka, the founder of Sony, but also from a gentleman named Mr. Shima, who at that time was a managing director of the corporation. They both encouraged me very strongly, "Isn't it time you leave NHK? It's just about time, isn't it? Why don't you join Sony? Come and join Sony." That's where it came from. It seemed almost without my personal involvement. People approached my superiors and discussed it with them. They also discussed the possibility of setting up an acoustics research department at Sony. So it seemed that, in a sense, the organization was being set up around me. Then I was called by my superior, who said, "So what's all this, then? Are you planning to join Sony?" I said, "No, I haven't really any real intention of going there." My boss responded, "You'll never be able to work there. You'll find it really tough. It's a totally different culture in Sony, and you'll never make it there."

At that time, in 1977, Masaru Ibuka had a lot of connections in NHK. He was a member of certain influential committees as well, and it seems that my influence was not so great and that things were being decided for me. I did a lot of thinking about my future. I was fifty at the time and thought, "How will I spend the next ten years? What will be my plan?" I strongly pondered the suggestions from Mr. Ibuka and from Mr. Shima, and couldn't help but come to the conclusion that while the post at NHK was a very good one, it was somehow different from hands-on development. I couldn't see any other way to get closer to real research again, to hands-on research. I realized I would like another new challenge. I thought to myself "Well, if Ibuka-san has such a strong opinion, then there must be something in it. There must be something that I can achieve there, and something that I can do in life at Sony." I decided to move at the end of the day.

Aspray:

Did you know Mr. Ibuka and Mr. Shima personally before this?

Nakajima:

Yes, The first contact with Masaru Ibuka came with the microphones from NHK. The connection with Mr. Shima was even more direct. Mr. Shima was not my direct boss, but was two layers above me at NHK before he moved over to Sony. So there was a strong connection there.

Aspray:

This next question is perhaps a little more difficult to answer. American and Japanese business practices are clearly somewhat different. In the United States, a company that wanted to hire away a key employee from another company would never talk to that company about it. Is this an unusual occurrence? What are the courtesies involved?

Nakajima:

[Translator to Aspray: I'll preface this myself by saying that I have heard Nakajima-san talking about this before, and it was a very unusual event. How much depth that he will want to go into about it, I'm not entirely sure.] By Japanese standards as well, Mr. Ibuka was way out of line. He was operating outside of traditional norms in approaching people at NHK and asking for me. That's very much Mr. Ibuka's personality. However many problems this caused, there was a sense in which I definitely had to follow Mr. Ibuka. When I joined Sony, I wanted to get started straight away on digital research, but it was Mr. Ibuka who was opposed to that, in fact.

Aspray:

Were you expected to retire at sixty and have only a ten-year career at Sony?

Nakajima:

[Translator to Aspray: At that time he was 55, or 56, and the retirement age was 65.] I definitely wanted to work on at least until 65, so that was why ten years was the figure.

Business Group Management

Aspray:

What were your original responsibilities with Sony?

Nakajima:

I was involved with the development of various analog audio products. When I first joined Sony I was assigned to R & D, as I expected. I was very surprised when two months later they said, "Now we want you to be in charge of an actual business group." I was still involved in overseeing R & D, but also at the same time had responsibilities for the audio business group, as it then was. Of course, in my job at NHK, I had not thought at all about business. All I had ever been concerned with was R & D. That's why I had such a shock. But once I had joined Sony and they said to me, "That's what you will do," I tried my best. Everybody with me seemed to have their futures decided by somebody else!

Aspray:

Was it customary for someone to have a responsibility for both an R & D unit and a business unit at the same time?

Nakajima:

I think it was rather special. The building we are in now was built for that purpose, within a year after my arrival at Sony, that is, to house Sony's audio R & D activities. My office was two floors below it. At that time, the large building that you may have passed on your way in was a production facility. Over there was the room where I had my other hat, if you like, the room for the business group manager. So I had two offices for the two different responsibilities. When I walked over the bridge between the two buildings, I switched my thoughts into research mode or back into business mode. The difference between research and business is that in business there are things that have to be decided immediately, and most of them have to be decided the same day. I gradually found that more and more of my time was being devoted to business rather than R & D, close to 90%. So I began to wonder why they had brought me to Sony in the first place.

Digital Recording and CDs

Nakajima:

But I still held onto the desire I had brought with me to Sony, to work on digital recording. One of the things that created problems for us was that Sony was just about to quit making calculators. Sony was producing a very large calculator called SOBAX and was about to quit that business. As a result of getting out of the calculator business, there was also a proposition to quit making the digital ICs that were actually used in the SOBACS, which were called MOS.

Aspray:

I don't understand why leaving this calculator business was a problem. Was it just an upheaval in the company?

Nakajima:

[Translator to Aspray: No, I think Mr. Nakajima is referring to a difficulty for himself. As I think he is going to clarify, there was a company trend away from digital at that time.] There seemed to be a complete turnaround against digital within the company.

Aspray:

What were the responsibilities of the audio business group and the audio research group?

Nakajima:

The audio group at that time covered the full line-up of Sony's products: amplifiers, tuners, speakers, microphones, you name it.

Aspray:

Was there anything foremost as the important technology to be developed for the next few years?

Nakajima:

Sony's audio department was, if anything, behind the times. It was struggling against its competitors. In other fields, Sony had market shares in the region of 30%, whereas we were in audio business looking at single figures, 6%, 8%, and so on. That was across the range of audio products. The struggle just to maintain our position against competitors coming out with some very good products was enough to occupy all of my time. But of course we were doing research, and we were studying various aspects of audio.

Aspray:

Did you have an opportunity to come back to your personal interest in digital audiotape?

Nakajima:

Forty researchers worked under me, and most of them were trying to keep up with our competition in the analog field. Therefore I decided to assign two researchers only to digital research. We started off with them putting together the same sort of large, cumbersome digital recorder that we had done in NHK. We ran up against the problem that there would be other people seeing it, that it was too big, too cumbersome, and too expensive. At that time, Mr. Ibuka was one of those who were very strongly saying, "Give it up! Just leave it, just put it aside." The point was, however, that Mr. Ibuka was in Gotanda and I was here. Because of the Yamanote train line, which runs around here, it's a very inconvenient place to get to. For my purposes, that was very good, producing just enough time for the soup to get cold. If we used a video recorder as a starting point, we thought that we could achieve a digital recorder. Basically, the signal to noise ratio and the bandwidth video recorder would help us invent digital audio equipment At that time, 1975, Sony had just brought out Betamax. Upon seeing that, I thought that was our opportunity to develop the audio recorder. We took the Betamax recorder without changing anything of the product itself, adapted it for audio signal input as opposed to visual signal input, and that was the basis of the digital recorder.

Aspray:

The Betamax had been the product of a different division of Sony?

Nakajima:

Yes, the video division. So, using the Betamax video recorder products as a base, we developed a PCM processor for audio signals and professional and consumer model digital tape recorders. That's the birth of DAT. The tape that was used in that was a Betamax videotape, but it was converted for audio signal.

Aspray:

This was a commercial product?

Nakajima:

Yes. The conclusion was that, if we can do this with a tape format, then surely we can achieve it with a disc also. This is the basis of CD development. An already existing development called Videodisc adapted that for audio signals and had an audio recording on a disc medium. We started by thinking it would be a simple transfer to work from tape and then an adaptation of the same sort of technology for disc. We didn't realize that it would be a much more difficult proposition. Compared to tape, the possibility of errors on disc are, as you know, much greater. As a solution to this problem we came up with the idea of using digital signal processing for error correction.

Aspray:

Was this done solely by Sony, or was this a project done in conjunction with others?

Nakajima:

Videodisc was a system that had already been developed, a Philips system. They had worked on this development with the target of producing a disc for video. We were also conducting similar, parallel research in Sony on videodisc. Putting a digital audio signal onto disc was an area of research in which Sony was ahead at that time. I certainly felt that the combination of Philips' skills and experience in the Videodisc area and Sony's experience in digital audio development could result in an excellent digital audio disc for the consumer. Another important point was that we were considering a software disc, in other words a pre-recorded music disc. Philips had the record company Polygram within its organization. Sony at that time had CBS-Sony, the joint venture in Japan. Between those two, the companies probably had more than a 50% share of the record market. There was very strong backing within the two companies on the software side, the music side, as well. The decision to develop the compact disc with Philips was based upon those two points. If the companies linked hands, they would link hands both in terms of a very good technological combination on the hardware side and a very strong software operation.

Aspray:

Was it common for Sony to take partners in technical developments?

Nakajima:

It was a very rare event. At that time, for a company like Sony, a Japanese company, to hook up with a non-Japanese company at the joint development stage for a certain product was highly unusual. That may have been the first example of its kind. If we look at the history of audio, and video as well, the list of failures in terms of standardization is probably much greater than the list of successes. Television is another example; we have PAL, NTSC, SECAM, and all the different transmission standards. In video, there are VHS and Betamax. I very strongly felt that if we didn't develop some sort of standard, there was no way we would be able to grow a worldwide market. From that point I thought it would be a very good idea to link up with a non-Japanese company.

Aspray:

Was there resistance within the company?

Nakajima:

Unusually for Sony, it was very well approved! It was given the fullest support within the company.

Aspray:

Can you outline the joint work?

Nakajima:

We began a series of regular meetings, once every three months. For the first one we all went to Eindhoven, to Philips' headquarters. Two months later they came here to Japan. One thing can be said about the process of development in digital, and similarly analog: it's very much a step-by-step process. One person thinks, "This is the way to do it." Then somebody improves on that, and somebody else then improves on that. This was the process that was taking place. We realized that if we didn't draw the line somewhere and say, "This is where we stop," we would not achieve a standard. That was when we decided on a joint 50/50 contribution. I think on both sides the feeling was, "Why on earth have we signed to a 50/50 cooperation agreement?" I think Philips felt that as well. There was a certain amount of anger within Sony about that. The reason, obviously, was that each side felt it was ahead in technological development.

Aspray:

What was the division of labor on the development?

Nakajima:

The process was basically one of constant discussion and exchange of views. The people involved in various aspects of development would all bring their ideas to the table, and then the discussions would begin. Because I don't speak English very much, I tended to take a back seat, listen very carefully to what was going on, and just let the experts on each different technology go to work, as it were. Not only between Philips and Sony as such, but also between the hardware and software people within each organization, i.e. between Polygram and Philips, and between Sony and CBS-Sony. There was also argument concerning aspects of the optical pickup and the optical pickup in relation to the disc. Obviously there was a lot of discussion, and it was hard going at times. But I'm very happy with the system decided upon, and I feel we were able to reach an agreement on a very good system.

Aspray:

Maybe we should quit for today — I think it's time.

Nakajima:

I think this is an important point: it's instinct; it's a matter of feeling. And also luck, insight and intuition.

Aspray:

Thank you.