  We have studied electronic structure of triangular lattice
Ir$_{1-x}$Pt$_x$Te$_2$ superconductor using photoemission spectroscopy and
model calculations. Ir $4f$ core-level photoemission spectra show that Ir $5d$
$t_{2g}$ charge modulation established in the low temperature phase of IrTe$_2$
is suppressed by Pt doping. This observation indicates that the suppression of
charge modulation is related to the emergence of superconductivity.
Valence-band photoemission spectra of IrTe$_2$ suggest that the Ir $5d$ charge
modulation is accompanied by Ir $5d$ orbital reconstruction. Based on the
photoemission results and model calculations, we argue that the
orbitally-induced Peierls effect governs the charge and orbital instability in
the Ir$_{1-x}$Pt$_x$Te$_2$.
