Technology & Philosophy

vol.5

The middlemen who help to
ensure the ultimate in NIKKOR quality

  • Vol. 1
  • Vol. 2

The middlemen who help to
ensure the ultimate in NIKKOR quality

Quality AssuranceHitoshi Imanari

I am in charge of ensuring the overall quality of development products and mass-produced products. Tochigi Nikon also functions as an engineering center. We also provide overseas manufacturing bases in countries like Thailand and China with technical and quality assurance assistance. Tochigi Nikon was in charge of this 24-70mm VR lens from trial production through mass production. In fact, Tochigi Nikon handles a large number of products. The number of products we handle is in the double digits, and we have even manufactured some for close to thirty years.

Hitoshi Imanari

Quality Assurance Section, Imaging Business Unit, Tochigi Nikon Corporation

Hitoshi Imanari's first real encounter with a camera was an SLR camera he used primarily to take group pictures of a club he belonged to at university. He chose to work at Nikon because the camera he used in the lab was a Nikon F. Initially, he worked on the mechanical design of interchangeable lenses. He later shifted to interchangeable lens quality assurance, where he remains today. Personally, he currently uses five interchangeable lenses, primarily with a Nikon Df, as well as a Nikon compact camera. He enjoys taking pictures primarily of landscapes, flowers, and the like. He has become quite interested in cooking of late, and enjoys photographing dishes served while traveling.

Production SupportTomohiro Ishibashi

I am in charge of first establishing the indicators used to evaluate productivity and then optimizing and improving the production process based on them. Improvements that increase productivity are not implemented just at Tochigi Nikon, but at related companies as well. In some cases, I also assist overseas manufacturing bases in increasing their acceptable product rate. In my case, the acceptable product rate applies not to aspects such as optical performance, but rather to sensory aspects, such as external appearance and operational feel, that can be addressed at the factory rather than in technical ways, and is used for quality improvement activities. With this 24-70mm VR lens, it was my job to increase product quality and production capabilities, and to find ways to increase the number of lenses that could be manufactured each day. I believe that fewer defects or problems in the production process increases overall product quality, ensuring that the products that finally reach end users are of higher quality.

Tomohiro Ishibashi

Production Engineering Department, Imaging Business Unit, Tochigi Nikon Corporation

When Tomohiro Ishibashi began working at Nikon, he worked with jigs and tools that used general-purpose equipment. He then spent 14 years producing trial components with machining centers, wire-cut EDM machines, etc. After, that, he was transferred to NTC for three years to manage production, and has spent the last four years and two months back in machining. Since returning to Japan, Mr. Ishibashi is willing to risk his popularity to put pressure on those at factories by creating a deep relationship with previously unrelated assembly and adjustment processes and throwing out unreasonable demands that he calls "improvements" with project activities to increase production efficiency, which imitate the Toyota production system.

AF-S NIKKOR 24-70mm f/2.8E ED VR

AF-S NIKKOR 24-70mm f/2.8E ED VR

Optical TechnologyYasuhiko Nishida

Once details of the optical design process, such as lens element curvature, center thickness, and details regarding the glass materials to be used are determined, it is my job to evaluate whether or not these details are actually possible. Initially, I place priority on the ease of production. My first response is always that the design is impossible and must be modified. This was true of the 24-70mm VR lens as well. Put simply, I receive Excel data that contains design target values and the like, and keep my eye on the optical design until it actually takes form. While the designers often have unreasonable demands, such as the development of new elements, I also try to accommodate them.

Yasuhiko Nishida

Products Engineering Department, Imaging Business Unit, Tochigi Nikon Corporation

Yasuhiko Nishida was first introduced to cameras in middle school. He began taking pictures of cars, in which he had an interest, and eventually found himself wanting a Nikon camera. He began working at Tochigi Nikon Corporation in his home prefecture because he liked creating things, and his study of the physical properties of electricity made him want to be an electrical engineer in the field of precision machinery. After two years, he was put in charge of optical technologies for imaging products. He had one- year training in optical design (at Nikon), and has worked on optical technologies ever since. Mr. Nishida came up with production methods for some parts of the viewfinder for the reproduction model of the Nikon SP and manufactured them. His favorite hobby is riding his motorcycle, and he always takes a camera with him to capture landscapes and the like that catch his eye.

Product EngineeringHiroshi Ikeda

During product development, I am involved in the mass-production trial stage. I am also in charge of finding and implementing improvements, such as increasing the quality of mass-produced products and reducing costs. My work with mass-production trials is quite varied, but is primarily concerned with designing jigs and tools, and processes, testing the quality of products, and analyzing problems.

Hiroshi Ikeda

Products Engineering Department, Imaging Business Unit, Tochigi Nikon Corporation

Hiroshi Ikeda's introduction to cameras came with one he received from his grandfather when he was in elementary school. When it came time for him to find a job, he may have hoped to find one related to cameras, ultimately returning home to work at Tochigi Nikon. For eight years he drove approximately 40 km each way to work in Otawara from his home in Utsunomiya. He remembers that the drive was fine for him because he liked driving. Except for some time spent at Nikon's Chinese manufacturing base, he has held the same post since he began working at Tochigi Nikon. To date, he has been involved with new product development of primarily interchangeable lenses and lens units for compact digital cameras.

Q. How are you involved with designers?

Product EngineeringHiroshi Ikeda

About two and a half years ago, I came back to the same position I held before being transferred to a manufacturing base in China for about five and a half years. While I was away, the way in which mass-production trials proceed had changed greatly. Put simply, it used to be that the design department simply presented drawings, and then technical examination began. Now, however, we use a system known as "front loading" where people from production engineering play a role in product development from the design phase, lending their viewpoint to product development. On the one hand, this has made the relationship between design and development stronger, but it has also increased the amount of information and data that we must deal with. Like Mr. Nishida, I receive this data at an early stage and give it form, and then present it to Mr. Imanari's quality assurance department for evaluation. There is a document of product specifications, basically a spec chart, for each product. I construct production techniques that can satisfy those specifications.

Optical TechnologyYasuhiko Nishida

Yes, even when the product is actually made, it often does not meet the target design values. As the target design values for this new 24-70mm VR lens were much higher than they were for the older 24-70mm lens, I really thought it would be impossible at first. However, we worked hard to find the causes of problems and to adopt measures to address those problems, finally achieving a product that was ready for mass production. With this 24-70mm VR lens, mass production was made possible by increasing the precision of lens components over and over again and implementing much more precise adjustment for greater optical performance, and by challenging and overcoming all previous limits.

A designer who places priority on performance vs. an engineer who places priority on work

Quality AssuranceHitoshi Imanari

With this 24-70mm VR lens, we assumed that the marketing target would be professional photographers. This means that quality indicators would be very high. With products like this, quality assurance has a very difficult time evaluating sensory aspects. For example, as aspects measured using inspection equipment are measured by a machine, the results will be the same no matter who does the measuring. If we consider products from the user's viewpoint, sensory aspects such as rendering performance, ghost, and operational feel are most important. However, it is very difficult to evaluate or judge these qualities. As demands regarding this lens were also great, we took a lot of test shots, with rival products as well, to determine whether or not it offered a level of quality that would satisfy everyone. We assumed the position that our lens would not just be equal to its rivals, but surpass them.

Q. What exactly is difficult for you?

Quality AssuranceHitoshi Imanari

Numerical values for targets, product evaluation indicators, and the like are determined by the design and quality assurance departments. However, simply having the same numerical MTF values does not mean that the level of performance will be the same. We often found ourselves amazed at the lens's excellent imaging characteristics, despite the fact that its measured values were quite low. We assume that there will be no problems if numerical values exceed a certain level, but results are sometimes completely different than expected with actual shooting. If part of the difference is based on the designer's intent or goals, it can be difficult to evaluate those results. This seemed especially true of this lens. Ultimately, quality is determined with steady work and a lot of test shooting. However, that is also what’s interesting about this work.

Production SupportTomohiro Ishibashi

To satisfy design demands in the assembly and adjustment process, we must continuously assemble products correctly. Therefore, we check jigs and tools very closely at the mass-production trial stage. Though it varies by product, a particular tool at an overseas base may be used several thousand times every single day. Therefore, we look at each tool to be sure that it is capable of the required daily work load. We look for ways to ensure both speed and precision, two characteristics often at odds with each other, at our factories. We do not forget to help and support factory workers, often providing advice to help them increase their skill level.

Product EngineeringHiroshi Ikeda

Basically, if it's not simple, it's not possible. While the accuracy of tools and jigs is very important, reproduction capabilities are most important. As Mr. Ishibashi stated, we must always remember that the same job or process may be performed 500 or 1,000 times per day, so we especially focus on reproduction capabilities.

Q. Are there any particularly memorable exchanges between you and engineering or design departments?

Production SupportTomohiro Ishibashi

Naturally, users demand that interchangeable lenses offer superior optical performance, but it is also important that we meet deadlines. Our mission with assembly and adjustment processes is to achieve the daily production target set forth with production planning. Therefore, we are always looking for ways to make production more efficient. We tend to contradict each other, but in order to maintain quality and meet production schedules, we must all work together with a strong sense of what needs to be done at a particular time.

Optical TechnologyYasuhiko Nishida

In order to reduce variations in optical performance with the new 24-70mm VR lens, we automated adjustment. When we received target numerical values from the designers, we decided that those values could not be achieved using existing technologies. We wondered whether design specifications could be modified, but they could not. Therefore, while the designers worked to apply as many requests from production to the design as possible, the factory tackled issues regarding portions of the design that could not be modified, in order to achieve the necessary optical performance. The older 24-70mm lens and the new 24-70mm VR lens were designed by the same person. Therefore, I had a good idea where problems might occur. We fought quite a lot with the older lens.