Patent ID: 7683358

Claim:
A radiation image read-out apparatus configured to perform a radiation image read-out operation, in which stimulating rays are irradiated to a stimulable phosphor sheet carrying a radiation image stored thereon, the stimulating rays causing the stimulable phosphor sheet to emit light in proportion to an amount of energy stored on the stimulable phosphor sheet during exposure of the stimulable phosphor sheet to radiation, and in which the light having been emitted by the stimulable phosphor sheet during exposure of the stimulable phosphor sheet to the stimulating rays is photoelectrically detected with a photomultiplier, the apparatus comprising: a reference light source configured to produce a reference light having a predetermined light intensity, sensitivity measuring means for acquiring a detection signal from an operation, in which the reference light having been produced by the reference light source is photoelectrically detected with the photomultiplier, and measuring a sensitivity of the photomultiplier in accordance with a relationship between the thus acquired detection signal and a reference signal, which has been set previously and which has a level in accordance with the predetermined light intensity of the reference light; and warning means for giving a warning in cases where the measured sensitivity of the photomultiplier is outside a predetermined range; and wherein the apparatus further comprises a stimulating ray cut-off filter configured to cut off the stimulating rays, which travel toward a photo cathode of the photomultiplier, the stimulating ray cut-off filter has a transparency range outside the wavelength band of the photostimulated emission, and the reference light source emits the reference light in said transparency range.