After concluding a contract in Dec. 2004, Seoul Metropolitan Subway Corporation has completed installing screen doors at Sadang Station on Line 2 at the end of August this year, successfully launching the first step for enhancing the comfort and safety of a hundred thousand people. As the city came to select the EEFL as the light source for advertisement boards designed to be placed on screen doors, consequently the lighting industry has also become keenly interested in the project.

Project Scale
A screen-door is a safety system that automatically opens and closes together with vehicle when the train arrives at the station. In the sign industry, the most interesting issue here is screen-door administration as a new media of advertisement. Among the 12 planned subway stations, Sadang Station first completed its screen-door installation last August by installing the total of 114 advertising boards incorporating into the EEFL as the lighting source and four 60’-PDP televisions. Screen-doors include the closed and handrail types, as there are two different types of subway stations: on the ground and under the ground. Sadang Station has applied the EEFL to the A, B, and E types of screen doors for lighting, except D type that is not for lighting. The size of each type is as follows: A type is 2.0m-width X 1.6m-height; B type is 2.5m-width X 1.6m-height; and E type is 2.0m-width X 1.0m-height. There is one inverter required for 10 EEFL’s on average. In case of E type, four inverters have been required to operating forty 980mm-EEFL’s; in case of A and B type, eight inverters have been respectively allotted for eighty 1,250mm-EEFL’s. A total of 114 EEFL light-panel advertising boards were mounted to screen-doors, of which A type counts 18, B type counts 20, and E type counts 76. In all the closed-type subway stations under the ground, the same number of EEFL light-panels and PDP televisions will be assigned.

EEFL’s Features
EEFL stands for Exterior Electrode Fluorescent Lamps. As the name suggests, the electrodes of the EEFL is installed externally, unlike other fluorescent lamps. Whereas other fluorescent lamps function with the electrodes connected to the inside of each end, the EEFL emits light by inducing electric discharge while sending electricity to the exterior electrodes. The EEFL can produce even luminance by reducing the electric voltage difference in between lamps based on its parallel connection, and is great as an internal light source for light panels since it has high intensity of illumination. Its slim size of less than 8mm also helps advertising boards to be slimmer and look so great. Director Kim Yun-su of YujinMetrocom Co., Ltd., managing the screen-doors of subway stations explained his reason for selecting the EEFL as the light source lied in the considerably thin size of the light panel. Screen-doors had to be limited in their thickness to ensure more space on the platforms, and the door-operating system and advertising boards had to be installed at the same time within that limited space. Director Hong Yong-deok of Yale Ad Lighting Co., Ltd. producing the EEFL-light panels said that the company received certifications for parts of the lamps, inverters, and frames of the light panel and making an effort on ensuring security of the product, considering the fact that the advertising panel should be lighted from 5 am to 1 am without pause. Director Ryu Won-pil of K.B.W Co., Ltd. said that the EEFL is capable of maintaining vivid visual images for a long time as its low volume of light emission minimizes thermal damages to the printed graphics. He also emphasized that the EEFL’s supplied to this project were made of lon three wave lamps that have superior-quality color realization. The first advertiser to be featured by the screen-door advertising boards is Hyundai Credit Card. Mr. Kim, Yujin Metrocom Co., Ltd. says: “Sadang Station will be administered as a ‘brand’ station for two months from Sep., through Oct. All advertising boards will feature advertisements of Hyundai ‘M’ cards. For next project, Seonreung Station is scheduled to be completed by June 18, 2006