CPFL stands for “Ceramic Poles Fluorescent Lamp”. It was invented by Santoma's ex-CTO, Dr. M. S. Yoon and his research assistant Mr. Hur. It was first introduced to the academic world and applied the patent to Korea and PCT as the title of “Fluorescent Lamp Having Ceramic Composite Electrode” which was denominated as “CPFL”,  a proper noun of merchandise by Mr. Walter Lin when the technology was introduced to Taiwan subsequently.


In May 2008, Mr. Walter Lin on behalf of Santoma Limited and Dr.M.S. Yoon on behalf of Inova Co., concluded the signing of co-own of the CPFL patent which was granted in August 2008 in Korea. Meanwhile, the joint party begins to secure patents in other countries by the priority right of PCT.

In Jan 1st, 2014, Dr. Yoon sold all his shares of Santoma, and transferred (his own and  on behalf of Inova) relevant rights to Santoma.  Santoma has solely and exclusively owned the patent and subsequent rights since then.  

CPFL stands for “Ceramic Poles Fluorescent Lamp”, and is called because its poles (electrodes) are made of a special linearly polarized dipole material. Before power-on, the ceramic grains at the poles (electrodes) are neutral (Fig. 1); after an external voltage is applied, it is then soon polarized, as shown in Fig. 2.


Fig.1 Power   Fig. 2 Power On


The ensemble diagram of a pole (electrode) is shown in Fig. 3, where the electrons from the ceramic poles (electrodes) are emitting by the electric field and impinge on the Hg molecules and ionize them. The ionized Hg ions and electrons then accelerate toward two opposing electrodes; meanwhile collide with other Hg and inert gas molecules and the ionized cloud become in plasma state ( Fig. 4)



Fig. 3 Electrons Expelled at Ceramic Pole



Fig. 4 CPFL: Conceptualized Exchanges of Electrons, 253.7 nm UV and Phosphor


An inverter is then used to apply power across the electrodes, and once the voltage is reverses, so goes the ionization direction. When the elevated mercury electrons return to the ground state they give off ultraviolet rays, primarily in 253.7 nm. The UV rays are converted into visible lights after colliding with the phosphor coating on the tube wall. A CPFL is similar in operation to that of EEFL (External Electrode Fluorescent lamp), but its structure is similar to that of HCFL (Hot-Cathode FL), or CCFL (Cold-Cathode FL). Thus we name it CPFL to differentiate our products from the others.