 |
 |
 |
||
 |
 |
 |
||
|
|
Column No.2 "Fluorescent lamps and Nemoto" (October 8, 1999) Nowadays, fluorescent lamps are found everywhere. Were you aware that this hasn't always been the case and that a Nemoto innovation was the key to the proliferation of these lamps? It is commonly thought that Toshiba (in collaboration with G.E.) produced the first fluorescent lamp in 1940. Few people know that fluorescent lamps had already been produced and sold by Nippon Reiko Denki Co. (Japan Electric Cold Light Company), established by Mr. A. Fujiki, the pioneer of Japanese glow-in-the-dark pigments. Mr. Fujiki developed the "Fujiki" fluorescent lamps with the assistance of a scientist, Mr. M. Ohmori. Both companies received manufacturing licenses from the Ministry of Commerce and Industry around the same time. According to JECLC records, in 1941, 240,000 tubes were supplied for military use and 60,000 pieces for civilian use.   Just after World War II power supply in Japan was not adequate, and fluorescents lamps were rapidly popularized as they had a far superior energy efficiency compared to incandescent lamps. One drawback, however, was the delay experienced when the lamps were turned on (which led to the Japanese vernacular of describing a hesitant person, "He is like a fluorescent lamp."). The reason was that the glow-starter bulb (See photo) did not ignite instantly. The mechanism of starters is such that, photons must hit the glow starter in order to activate it, but this was difficult to accomplish in dark areas. This resulted in the well-known flicker effect after a lamp would be lit. The delayed ignition problem led to research into the use of radioactive self-luminous paint in the starters. With the light energy required to ignite the starter provided by the insertion of the luminescent excitation source, a solution appeared to be in sight. Difficulties in integrating this "hand painted" light source into the automated production process as well as potential radioactive contamination of the workplace both helped to keep this method from being implemented.  At the request of the Science and Technology Agency, Nemoto began to search for a solution to this problem. A nickel wire plated with a radioisotope (63Ni or 147Pm) was developed as a result. This radioactive nickel wire was over-coated with pure nickel to completely seal the radioactivity in conformance with quality standards. This new product was presented to the Illumination Society in 1974.  The sealed RI*1 electrodes (See photo) are offered in various types and are used for fluorescent lamp glow starters as well as other discharge lamps such as neon and mercury lamps. These electrodes are used also to improve the performance of lightening arresting devices. Components equipped with the Nemoto RI electrodes are also utilized in various electric appliances. The applied radioactivity is about 2 kBq (kilo becquerel)*2 of 63Ni and about 10 kBq of 147Pm. As both radioisotopes are Beta-ray emitting nuclides, radioactivity can be blocked by the glass housing to ensure safety. Nemoto's RI lead-in-wires are used throughout the world. By 1998, a total of 4.7 billion pieces, including 2.8 billion glow starters had been produced. Remarks) Copyright 1999,2000 by Nemoto & Co.,Ltd , Yoshihiko Murayama, Hiro Yamamoto. |
