We have demonstrated that it is possible to fabricate the conical multiplex hologram as an image-plane hologram using a simple optical system. Based on ray tracing, the imaging properties of lenses, and coordinate transformation, a theory directly relating the observed image point to the original object point is formulated, which facilitates numerical simulation of the whole observed image. A search over the holographic parameters shows that a condition for the least-distorted image, limited by the particular shape of the hologram, can be obtained. Numerical simulation is given, together with some experimentally reconstructed images of a real object. The result shows that it indeed eliminates the so-called picket-fence effect as encountered in the traditional multiplex holography.