  Under the scenario of generalized measurements, it can be questioned how much
of quantum uncertainty can be attributed to measuring device, independent of
the uncertainty in the measured system. On the course to answer the question,
we suggest a new class of entropic uncertainty relation that differentiates
quantum uncertainty from device imperfection due to the unsharpness of
measurement. In order to quantify the unsharpness, we {suggest} and analyze the
quantity that characterizes the uncertainty in the measuring device, based on
Shannon entropy. Using the quantity, we obtain a new lower bound of entropic
uncertainty with unsharpness and it has been shown that the relation can also
be obtained under the scenario that sharp observables are affected by the white
noise and amplitude damping.
