Patent ID: 6973161
Filing Date: 2005-12-06
Classification: G01N

Abstract:
1. An X-ray foreign material detecting apparatus comprising: an X-ray generating section which irradiates a predetermined energy amount of X-rays at a single irradiation time; a conveying section which successively conveys an inspected object at a predetermined speed so as to cross the predetermined energy amount of X-rays irradiated at the singe irradiation time from the X-ray generating section, the inspected object including an object which is successively produced and may be changed in shape during conveyance; a first scintillator disposed along a transmitting direction of the X-rays transmitted through the inspected object successively conveyed by the conveying section at a predetermined speed, which converts to light, one portion of transmitted X-rays transmitted through the inspected object, obtained by exposing the predetermined energy amount of X-rays at the single irradiaton time, from the X-ray generating section to the inspected object which is being conveyed at the predetermined speed by the conveying section; a first visible light reflector which reflects the light converted by the first scintillator; a first sensor module which includes a first light receiving element for receiving the light reflected by the first visible light reflector, and outputs a first electric signal corresponding to a first X-ray energy amount that the one portion of the transmitted X-rays has by using the one portion of the transmitted X-rays transmitted through the inspected object; first X-ray energy amount converting means which is disposed under the first sensor module along a transmitting direction of the X-rays transmitted through the inspected object successively conveyed by the conveying section at a predetermined speed, which receives a remaining portion of the transmitted X-rays transmitted through the inspected object excluding the one portion of the transmitted X-rays received by the first sensor module, obtained by exposing the predetermined X-ray energy amount of X-rays during the single irradiation time from the X-ray generating section to the inspected object which is being conveyed at a predetermined speed by the conveying section and converts into X-rays having a second X-ray energy amount different by a predetermined magnitude fro the first X-ray energy amount by using the remaining portion of the transmitted X-rays transmitted through the inspected object; a second scintillator which is disposed under the first X-ray energy amount converting means along a transmitting direction of the X-rays transmitted through the inspected object successively conveyed by the conveying section at a predetermined speed, which converts to light, the X-rays having the second X-ray energy amount converted by the first X-ray energy amount converting means; a second visible light reflector which reflects the light converted by the second scintillator; a second sensor module which includes a second light receiving element for receiving the light reflected by the second visible light reflector, and outputs a second electric signal corresponding to a second X-ray energy amount different from the first X-ray energy amount, at substantially the same time as the first electric signal output from the first sensor module, by using the X-rays having the second X-ray energy amount; second X-ray energy amount converting means which is disposed under the second sensor module along a transmitting direction of the X-rays transmitted through the inspected object successively conveyed by the conveying section at a predetermined speed, which receives a remaining portion of the transmitted X-rays transmitted through the inspected object excluding the one portion of the transmitted X-rays received by the first and second sensor modules, obtained by exposing the predetermined X-ray energy amount of X-rays during the single irradiation time, from the X-ray generating section to the inspected object which is being conveyed at a predetermined speed by the conveying section and converts into X-rays having a third X-ray energy amount different by a predetermined magnitude from the first X-ray energy amount and the second X-ray energy amount by using the remaining portion of the transmitted X-rays transmitted through the inspected object; a third scintillator which is disposed under the second X-ray energy amount converting means along a transmitting direction of the X-rays transmitted through the inspected object successively conveyed by the conveying section at a predetermined speed, which converts to light, the X-rays having the third X-ray energy amount converted by the first X-ray energy amount converting means; and a third sensor module which includes a third light receiving element for receiving the light converted by the third scintillator, and outputs a third electric signal corresponding to a third X-ray energy amount different from the first X-ray energy amount and the second X-ray energy amount, at substantially the same time as the first and second electric signals output from the first and second sensor modules, by using the X-rays having the third X-ray energy amount; wherein presence/absence of a foreign material mixed in the inspected object, successively conveyed by the conveying section at a predetermined speed can be detected at high speed with high accuracy irrespective of a change in shape of the inspected object during conveyance, in accordance with the first electric signal, the second electric signal and the third electric signal, respectively corresponding to the first X-ray energy amount, the second X-ray energy amount which is different from the first X-ray energy amount and the third X-ray energy amount which is different from the first X-ray energy amount and the second X-ray energy amount, which are output from the first, second and third sensor modules with respect to the same portion of the same inspected object at substantially the same detection time.