  Effects of time-delayed-feedback on pattern formation are studied in
symmetrical bistable media. The results show that the time delay alters the
behavior of the front bifurcation remarkably. The critical point of the
Nonequilibrium Ising-Bloch bifurcation is shifted, which results from the
competition between the feedbacks of the two variables. The stability of the
front to transverse perturbation is also changed by the time delay, leading to
a transition between spiral and labyrinthine patterns. One can control the
pattern formation in bistable media by using time-delayed-feedback.
