A light source device includes at least one discharge tube, a discharge
medium sealed inside the discharge tube, and first and second electrodes
for exciting the discharge medium. The first electrode is arranged inside
or outside the discharge tube, and the second electrode has a plurality of
contact portions at which the second electrode is in contact with an outer
surface of the discharge tube. The contact portions are located at
different distances from the first electrode and are provided
discontinuously. Xenon gas and at least one selected from argon gas and
krypton gas are sealed in the discharge tube, in which the xenon gas
accounts for 60 vol % to 80 vol %. Thus, it is possible to provide a light
source device and a liquid crystal display device that provide light
emission with high brightness and excellent brightness distribution and
that can be manufactured readily.
