||Although the Circline fluorescent lamp was invented in America and also quickly further developed by the European manufacturers, it never became an especially popular light source in either of those countries. Meanwhile however, it was embraced with unparalleled popularity in what might well be referred to as its adopted home country - Japan. No other country has further developed the technology, or applied it so widely across both residential and commercial lighting as Japan. This unusual side-reflector lamp is typical of that country's pursuit of excellence in refining the circline concept for optimum performance.
Although reflector fluorescent lamps have existed since the 1950s, it took many more decades before the same princples were applied to a circular lamp. The first known combination of a reflector coating on the upper surface of a circline lamp was introduced by Toshiba around 2005, in its PRIDE series of high performance fluorescents. The detail photograph showing the ends of the discharge tube with part of the plastic cap removed appears to show three distinct coatings. First a reflector coating on the upper surface, then a phosphor coating around the entire tube circumference, and then a second phosphor coating, which extends slightly further towards the tube ends than either of the other coatings. The fluorescent coating on PRIDE lamps is a triphosphor type, delivering improved colour rendering, better efficacy and better lumen maintenance.
Normally the Japanese circline T9 lamps of 225mm diameter are rated 30W, but this model draws just 28W. Possibly it contains a percentage of krypton, to offer a small energy saving vs the 30W original.