  We extend the Higgs triplet model so as to include dark matter candidates and
a simple suppression mechanism for the vacuum expectation value (v_Delta) of
the triplet scalar field. The smallness of neutrino masses can be naturally
explained with the suppressed value of v_Delta even when the triplet fields are
at the TeV scale. The Higgs sector is extended by introducing Z_2-odd scalars
(an SU(2)_L doublet eta and a real singlet s_2^0) in addition to a Z_2-even
complex singlet scalar s_1^0 whose vacuum expectation value violates the lepton
number conservation by a unit. In our model, v_Delta is generated by the
one-loop diagram to which Z_2-odd particles contribute. The lightest Z_2-odd
scalar boson can be a candidate for the dark matter. We briefly discuss a
characteristic signal of our model at the LHC.
