PURPOSE: To improve efficiency in reading by arranging plural arced accumulative fluorescent screens on the same surface of a cylinder, scanning them with an excitation beam while it is rotated, and thereby reading a latent image.

CONSTITUTION: A light guide 3 translates as it rotates; that is, the guide 3 translates along a center axis as it rotates with the center axis of an incoming end 31 having as its rotation center. As it does so, the outgoing end 32 of the light guide 3 passes above the accumulative phospher plates 41 and 42 in that order; the central angle of the circular arc of each of the accumulative fluores cent screens 41 and 42 is about 90°. Since the light guide 3 constantly translates, when the outgoing end 32 comes above the original accumulative fluorescent screen after its one rotation, it is away from the previous reading position a prescribed distance toward the axial direction, and the reading position does not overlap another. Thus, the two accumulative fluorescent screens 41 and 42 are read at a time while the light guide 3 makes one rotation, and efficient reading is achieved.