Views: 0 Author: Site Editor Publish Time: 2026-01-15 Origin: Site
A research team led by Shinichiro Inoue, Director of the Future ICT Research Institute at the National Institute of Information and Communications Technology (NICT), has successfully developed the world's first "Deep UV LED Large Space Disinfection System" capable of safely and rapidly inactivating airborne bacteria in large spaces such as concert halls. By operating the system in an actual large hall, the research team confirmed its effectiveness and verified its safe operation.
The research team developed a module that can selectively irradiate deep ultraviolet light only to the upper space of the hall by precisely controlling the light distribution angle (light diffusion angle) of high-intensity deep ultraviolet LEDs.
The contaminated lower-level air is quickly convected to the upper level through the air supply fan installed in the lobby. After being irradiated and inactivated by deep ultraviolet light emitted by the modules on the upper level, it becomes clean air and is recirculated to the lower level.
As a result, deep ultraviolet light will not be irradiated to the audience seats in the lower part of the hall, while only applying sufficient intensity of deep ultraviolet light to the upper part of the large space, thus achieving safe and high-speed sterilization of the large space, which was previously difficult to achieve. While ensuring high safety, a system that sterilizes the entire large space at high speed through deep ultraviolet light is realized.
The module utilizes high-intensity deep ultraviolet LED chips with an emission peak wavelength in the 265nm band, which has the highest sterilization efficiency, for multi-chip packaging, and is combined with a paraboloidal reflector. While achieving high light output at the watt level (1.1 watts), it also achieves extremely high directivity.
After the research team installed and operated the system in the lobby of Sakura Mate at the Kumagaya Cultural Creation Center in Japan, they evaluated the time required to inactivate airborne bacteria within a volume of 9,200 cubic meters under long-distance irradiation on a scale comparable to a concert hall.
After the research team installed and operated the system in the lobby of Sakura Mate, a cultural creation center in Kumagaya, Japan, they evaluated the time required to inactivate airborne bacteria within a 9,200 cubic meter area under long-distance irradiation on a scale comparable to a concert hall.
The installed system utilizes a module with four chips in series packaging, each delivering a light output of 500 milliwatts. After light distribution control, the total light output reaches 1.1 watts. Three such modules are employed, operating at a combined light output of 3.3 watts.
The reference mercury lamp system used for comparison with this system employed a module equipped with a commercially available low-pressure mercury lamp (Philips TUV PL-L 18W/4P, rated light output 5.5 watts, dominant wavelength 254nm). After light distribution control through shading blinds, the light output was 0.33 watts, with a total of 3 units used, resulting in a total light output of 0.99 watts. The prototype was produced with the assistance of Iwasaki Electric.
In systems using mercury lamps, although the light output of the lamp itself is high, the size of the light source (luminous volume) is large, and the light radiates in all directions, resulting in low light distribution controllability.
In addition, to prevent deep ultraviolet light from reaching the lower audience seats, shading blinds are needed to block the light diffusing downwards. Therefore, the light output after light distribution control will be significantly attenuated.
The illuminator of the deep ultraviolet LED irradiation module used this time is extremely small and has high light distribution controllability. Its characteristic is that even with light distribution control, it can still achieve high light output at the watt level.
The comparison results showed that the time required to inactivate 99.9% of the test virus (human coronavirus 229E) was estimated to be 42 minutes using the deep ultraviolet LED irradiation module, which was 72% shorter compared to 150 minutes using a mercury lamp.
