26pC06
多極磁場中多相交流放電プラズマを応用した空間的放射一様性の高い光硬化用UV照射装置

UV photo-curing lamp-array with high spatial irradiation uniformity
by applying a poly-phase ac discharge/plasma in a multi-pole magnetic field松本 和憲
Kazunori MATSUMOTO

2[μW/cm /nm]

Spectral irradiant flux density

Wavelength [nm]Fig. 2 Typical spectral irradiant flux density emitted
from the UV lamp filled with a N2 and O2 mixed-gas
クトル
2Irradiant flux density [mW/cm ]Experimental method and results
Figure 1 shows a photograph of visible light emitted
from a set composed of six loop-shaped lamps arrayed ina plane, where gap spaces among lamps and four walls
surrounding the set are wholly covered with aluminumreflectors. A six-phase ac power source (156kHz, ~300W)
is supplied parallelly to six-divided electrodes. Figure 2
shows a typical spectrum irradiated from the lamp-set,
where a nitrogen (90%) and oxygen (10%) mixed-gas isfilled at the pressure of 0.5Torr. The component (UV I )ranging over 220-280nm is emitted from excited nitricoxide produced during the discharge/plasma, whichenable photo-curing under small irradiation energy.
Figure 3 shows spatial irradiating UV distributions
with respect to the horizontal direction, where data aremeasured at y=155mm, z=20mm. It was found that thehorizontal distribution became considerably uniform overthe full width when horizontal mirror-walls were locatedat the distance of half pitch of between adjacent lamps.
Figure 5 shows spatial intensity distributions with respect
to the longitudinal direction, where data are at x=84mm,
z=20mm. We found that the longitudinal distribution also
became fairly uniform over the full length when thelongitudinal walls were located at the distance of 1~0.5
lamp’s pitch. Furthermore, the results of spatial distribution with respect to the height direction indicated that theintensity were nearly constant over z=15~30mm.
The above feature of three dimensionally uniform
irradiation distribution is industrially valuable in order toperform homogeneous UV photo-curing processes even if
substrates have some curved surface.

～400

Horizontal direction x [mm]Fig.3 Spatial irradiant intensity distribution of the arraywith respect to the horizontal x-directionIrradiant flux density [mW/cm2]

Introduction
Ultra-Violet (UV) photo-curing of hard coating is
widely used in various industrial fields since it has nosmell and takes only a few seconds. However, highpressure mercury lamps have been used, that consume
large electric power and contain large amount of mercury.
As issues concerned with energy and environment havebecome serious, the needs rise intensely for a new lampthat has no mercury and enable photo-curing under small
electric power.
A lamp had been proposed by us, which contained nomercury but molecular gases and nitrogen and enabledphoto-curing under ten times smaller electric energy thanconventional ones. Demands for a lamp with high spatial
uniformity and irradiating intensity are made from thepoint of view of practical & industrial use.

～260

富山県大工
Faculty of Engineering, Toyama Prefectural University

Longitudinal direction y [mm]Fig.4 Spatial irradiant intensity distribution of the arraywith respect to the longitudinal y-direction