An imaging recorder wherein a linear array of laser diodes is mounted to project the output of the diodes onto a thermally activated photosensitive material movable along a predetermined path. The array of diodes is linearly aligned in a direction parallel to the path of movement of the material and the laser diodes are activated simultaneously as a group. Optical means are provided between the array of laser diodes and the material to provide an imaging spot on the material which is elongated in a direction perpendicular to the path of movement of the material.