  Using a mean field theory on the von Neumann lattice, we study compressible
anisotropic states around $\nu=l+1/2$ in the quantum Hall system. The
Hartree-Fock energy of the UCDW are calculated self-consistently. In these
states the unidirectional charge density wave (UCDW) seems to be the most
plausible state. We show that the UCDW is regarded as a collection of the
one-dimensional lattice fermion systems which extend to the uniform direction.
The kinetic energy of this one-dimensional system is induced from the Coulomb
interaction term and the self-consistent Fermi surface is obtained.
