Polycone scanning system with multiple beams

Abstract From the Canadian patent

This invention relates to a pyramid polygon scanner wherein the differential scan length between multiple beams can be eliminated by tilting thebeams with respect to the photoreceptor surface. Then the beam with the shorter scan lengths when the beams are normal to the photoreceptor travel a greater, distance before they impinge on the photoreceptor. At the start or end of scan the scan angle is not zero, so the scan lengths for the beams with the larger traveldistances are increased by the extra distance multiplied by the tangent of the scan angle. At the proper tilt angle, all scan lengths at the photoreceptor are the same. Since the angular scan rate of all the beams are always the same …