FOREIGN MATTER DETECTION DEVICE AND FOREIGN MATTER DETECTION METHOD

• Main Author: MIYAZAKI ITARU
• Format: Patent
• Language: English; Japanese
• Published: 05.10.2017
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To highly accurately perform foreign matter detection for objects to be inspected different in thickness by using a photon detection type X-ray sensor.SOLUTION: A photon detection type is used as X-ray sensors 31to 31, and an amount of the x-ray emitted from an X-ray generation part 22 is gradually and periodically changed for every predetermined time by X-ray amount variable means 22b. Transmission image data generation means 40 determines to which of a plurality of areas the crest value of the pulse signal outputted during a predetermined period enters from the X-ray sensors, and generates a plurality of pieces of transmission image data different in X-ray transmission energy by using an accumulation result obtained by accumulating the number of inputted pulse signals within the predetermined period for each area. Determination means 50 performs the image processing including a subtraction process of transmission image data obtained during the period in which a variable stage of the amount of the X-ray emitted from the X-ray generation part 22 from among the plurality of pieces of transmission image data is the same, and determines the presence or absences of a foreign matter inside the object to be inspected.SELECTED DRAWING: Figure 1 【課題】光子検出型のＸ線センサを用いながら厚さの異なる被検査物に対する異物検出を高精度に行なう。【解決手段】Ｘ線センサ３１１〜３１Ｎとして光子検出型を用い、Ｘ線発生部２２から出射されるＸ線の線量をＸ線線量可変手段２２ｂによって所定時間毎に段階的に且つ周期的に可変させる。透過画像データ生成手段４０は、Ｘ線センサから所定期間内に出力されるパルス信号の波高値が複数の領域のいずれに入るかを判定し、所定期間内のパルス信号入力数を領域毎に累積して得られた累積結果を用いて、Ｘ線透過エネルギーが異なる複数の透過画像データを生成する。判定手段５０は、複数の透過画像データのうち、Ｘ線発生部２２から出射されるＸ線の線量の可変段階が同一である期間について得られた透過画像データ同士のサブトラクション処理を含む画像処理を行ない、被検査物内の異物の有無を判定する。【選択図】図１