In a radiation image read-out apparatus, a line stimulating light beam is
projected onto a stimulable phosphor sheet, and stimulated emission
emitted from the irradiated portion of the stimulable phosphor sheet is
detected by a line sensor. A refractive index profile type lens array is
disposed between the stimulable phosphor sheet and the line sensor. The
photoelectric convertor elements of the line sensor and the refractive
index profile type lenses of the refractive index profile type lens array
are arranged at pitches such that the frequency band of the periodic
pattern generated due to the pitches of the refractive index profile type
lenses in said refractive index profile type lens array are higher than
the frequency band of a radiation image information reproduced on the
basis of the image signal.
