Company history

The company began in September 1948 as a one-man shop in Hamamatsu, the Tokai Electronic Research Institute, making and selling vacuum tubes in the disorder of the postwar years. Its founder, Horiuchi Heihachiro, had been an assistant to Takayanagi Kenjiro — the man who first transmitted a television image in Japan — and his part of that work was the phototube, the device that turns light into an electrical signal. In September 1953 the workshop was incorporated as Hamamatsu TV Co. with $1,389 (¥500,000) in capital; the name came from its main product at the time, camera tubes for the television sets Japan had only just begun to broadcast to. It would keep that name for thirty years.

The decisive choice was made at the outset, and it was a refusal. Volume products would have meant subcontracting for the large electronics makers; a device whose performance stood one clear step above the field could be sold at a price of its own making. Hiruma Teruo, whom Horiuchi had brought in at the founding and who would run the company from 1978, made that into doctrine — a “research industry” (研究工業) that works on technology before it becomes an industry, in Takayanagi’s spirit of pursuing what does not yet exist.

The photomultiplier tube proved the thesis. A PMT amplifies light so faint it is measured in single photons, and it is both hard to manufacture and wanted in small numbers — two facts that read as obstacles but functioned as walls, keeping the volume manufacturers out. Hamamatsu commercialised its own around 1962, took it to the United States, and took share from RCA by answering every customer complaint that the incumbent had learned to shrug off. Sales offices and plants followed the tubes: New York in 1966, the Ichino works in 1964, a German subsidiary in 1973. In April 1983 the company dropped “TV” from its name and became Hamamatsu Photonics — no longer a supplier of parts for television sets, but a firm defined by the thing it studied.

Public money arrived a year after the new name: over-the-counter registration in August 1984, then a widening research and sales base — the Tsukuba laboratory in 1985, French and British subsidiaries in 1985 and 1988, the Central Research Laboratory in 1990. In 1987 Toyota Motor put $26.3M (¥4bn) into the company. What that money was buying was not the fashionable new name but the photomultiplier and positron-detector technology behind it; Hiruma had already refused to be taken under the wing of a general electronics group, and being able to choose his investors was part of what the independence was for. The company reached the Tokyo Stock Exchange’s second section in 1996 and the first section in 1998.

The work that fixed its reputation had begun earlier and outside the market entirely. In 1979 Koshiba Masatoshi of the University of Tokyo asked Hamamatsu for a photomultiplier 20 inches across — a size no one had built. The tubes lined the walls of a water tank a kilometre underground at Kamioka, catching the faint Cherenkov light thrown off when a neutrino strikes a water molecule, first in Kamiokande and from 1996 in Super-Kamiokande.

Koshiba’s observations won the Nobel Prize in Physics in 2002, and Kajita Takaaki’s at Super-Kamiokande won it again in 2015. Neither prize was Hamamatsu’s, but both rested on its glass, and the physics community knew it. From then on the company occupied a position that is difficult to describe as a market at all: the sole practical supplier of a component that fundamental science cannot do without.

The monopoly held because of how it was made. A roughly 90% world share in photomultipliers was never defended by patents or price so much as by the difficulty of the craft and the smallness of the demand — the classic niche-top structure, safe precisely because no one with a volume factory has a reason to attack it. The tube business turned over on the order of ¥45–50 billion a year through the 2010s, steady rather than growing.

Growth came from the semiconductor side of the same physics. Photodiodes and SPAD arrays sold to the makers of wafer-inspection equipment — KLA, Applied Materials, ASML, Tokyo Electron — carried Hamamatsu along on the shrinking of the transistor, and the opto-semiconductor business overtook the tubes. Hiruma Akira, son of Teruo, became president in 2009 and widened the company on those two fronts, semiconductor inspection and medical imaging, while a Chinese sales company (2011) and a Belgian European holding company (2020) put the structure abroad on a firmer footing.

Then the pandemic delivered a windfall from an unusual direction. Research budgets swelled — mRNA vaccine work, mass PCR testing — at the same moment as a semiconductor capital-expenditure boom, and both ran through Hamamatsu’s catalogue. Revenue rose from ¥140.3 billion in the year to September 2020 to $1.6B (¥209bn) in FY2022, about 58% in two years, with operating profit up roughly 2.6 times. It was the best stretch in the company’s history, and almost none of it was of its own making.

In September 2022 Hiruma Akira explained why the next president would not be a Hiruma: the business was moving from selling tubes and sensors as parts toward modules and systems that combine a light source with a detector, and building those demanded cross-departmental systems knowledge and relationships with foreign customers. That December Maruno Tadashi — a career engineer from the systems division who had built the European and American accounts and led the NKT Photonics deal — became the third president, ending the founding family’s seventy-year run. Two months earlier the company had moved to the TSE’s new Prime market.

The acquisition announced in June 2022 and completed in May 2024 addressed the shape of the weakness rather than any shortfall in the strength. NKT Photonics of Denmark, bought for roughly $319.7M (¥42bn), brought supercontinuum and fibre-laser technology — the emitting half of photonics, which Hamamatsu had spent seventy years not doing. The Danish government blocked the deal once before letting it through, and it took fourteen months to close: light technology had become a security matter.

It closed into a downturn. Chip-tool inventory correction, the pandemic research bulge draining away and budgets normalising all landed together: FY2024 revenue fell about 8% and operating profit about 43%, and FY2025 operating profit fell again, to ¥16.2 billion. Seventy-odd years on from a vacuum-tube workshop, the company holds an unassailable position in a market that is too small to carry it and a newly bought laser business that has yet to prove it can. Whether the acquisition becomes a second pillar or an expensive hedge is the question the third generation inherits.