Young and passionate — the days of my apprenticeship.
The goal of optical design is to control light.
Mr. Tanaka, you have been continuously engaged in optical design ever since you joined Nikon. Did you study optics at university?
No, I didn’t. My department was physics, and my subject of study was the physical properties of materials. There was one senior studying laser oscillation who was one of my acquaintances, but no real hint of optics was present in my life at that time.
Does this mean it was only since you joined Nikon that you started studying optics?
Yes, that’s correct. I was assigned to the optical design department when I entered the company. This didn’t seem strange in any way. Colleagues who entered the company the same year as me had no experience of having studied optics at university either. What’s more, the basis of optics is physics in its essence, so I wasn’t particularly worried about this.
What product did you first deal with at Nikon?
My first project was to develop a high-temperature microhardness tester, intended to measure the hardness of materials such as metals or ceramics at high temperatures. The tester creates an indentation on a sample using a compression loader. The dimensions of the indentation formed are then used to calculate the hardness of the material.
Did you design the lenses used for this tester?
Yes, I designed the lenses as well as the entire optical system for it. Designing a new lens somewhat differs from creating an overall optical system. It concentrates on the creation of a lens that assures less aberration for sharper focusing and reduced color blurring. On the other hand, with a complete optical system it is crucial that light achieves the ultimate goal of its mission by appropriately and effectively routing optical paths inside equipment. A high-temperature microhardness tester comprises such functions as observation, illumination and measurement optics. It's the design of the optical system that determines the relative positions of these functions.
It’s all about designing an entire system that makes optimum use of light, isn’t it?
Yes, it is. Being young, however, I was not yet able to handle all aspects of the project by myself at that time. Senior engineers helped me with their advice and I managed to complete the task.
You must have spent a lot of time completing this mission.
No PCs were yet available. In those days we had to spend a long time just waiting for the results to come out from a computing center. Results were output twice a day. Waiting for them, I had plenty of time in which to read reference books and materials. I felt as if I were back at college. It would be quite unthinkable today.
I occasionally had to develop software prior to the optical design of a new product. This was enjoyable, too.
Which project do you think increased your confidence as a professional optical designer?
About 10 years after I joined Nikon I was assigned a project to develop a measuring microscope. This equipment was used to measure dimensions of components and products on manufacturing lines. I designed the whole optical system, including the objective lens of the microscope. Before starting this task, I had been working under the command of a senior engineer. During this project, I gained the confidence to work as an engineer independently.
So it took 10 years of hard work before you were recognized as an independent engineer. What’s more, it’s noteworthy that you were also developing your own software to perform the mission.
Well, in those days, there was no software that could fully satisfy our requirements. It was particularly difficult when we were asked to create innovative products, such as Nikon firsts and world firsts. It was impossible to start the development of such a product unless you first devised the software to design it. One of these efforts resulted in the creation of Japan's first parallel-beam-path zoom stereomicroscope. This instrument is used for the repair of watches, enabling a stereoscopic view of minute components. In order to successfully realize its design, we employed a zoom lens with a decentered optical system*. I had to create the software program myself in order to design this microscope.
The instrument also enabled photography, in addition to its primary function of achieving an excellent microscopic view, which led to better sales than previously planned. I remember this product very well for these special reasons.
Were you still using the computing center as before for designing this microscope?
Not any more. By that time, computers were being rapidly reduced in size, and we were able to carry out the programming via our own minicomputers. We typed on keyboards and the results came out on paper rolls. It was fascinating to suddenly have this convenient tool at hand. It was still primitive, though. All we could write was a mere 500 lines or so of programming. It is quite unthinkable when you compare it with today’s machines, which require 100,000 to 200,000 lines for ordinary software programming.
It is quite challenging and fun to design a product from nothing. Well, hard work was not a problem at all at that time, because I was full of vigor, being young. (Laughter)
So, the progress of computer technology greatly contributed to the advancement of your work, Mr. Tanaka?
I was glad to be around at a time when computers were rapidly evolving. I was working hard in optical design, acquiring various knowledge and technologies related to optics. I loved this work very much. But creating software also gave me extra enjoyment, and I became totally absorbed. I am an engineer that designs optical products. This engineer is also a programmer who writes software to design the optical product. The software must be totally different from any available on the commercial market, as it must be packed with special knowhow of both aspects by one and the same developer. This brought differentiation in product design making us successful over the competition. The software of my programming is still used by lens designers at Nikon.
- *Decentered optical system
An ordinary lens system is designed with lenses aligned on one optical axis. In a decentered system, certain lenses are positioned away from the central axis.