  We describe the deformed covariant phase space corresponding to the so-called
kappa-deformation of D=4 relativistic symmetries, with quantum ``time''
coordinate and Heisenberg algebra obtained according to the Heisenberg double
construction. The associated modified uncertainty relations are analyzed, and
in particular it is shown that these relations are consistent with independent
estimates of quantum-gravity limitations on the measurability of space-time
distances.
