  Using the von Neumann lattice formalism, we study compressible anisotropic
states around the half-filled Landau levels in the quantum Hall system. In
these states the unidirectional charge density wave (UCDW) state seems to be
the most plausible state. The charge density profile and Hartree-Fock energy of
the UCDW are calculated self-consistently. The wave length dependence of the
energy for the UCDW is also obtained numerically. We show that the UCDW is
regarded as a collection of the one-dimensional lattice Fermi-gas systems which
extend to the uniform direction. The kinetic energy of the gas system is
generated dynamically from the Coulomb interaction.
