| 摘要 |
Provided is a light tester that can reduce misdetection of pinholes and can reduce the unwanted removal of non-defective can bodies that arises from said misdetection. A light tester 1 that is provided with: a first inspection pattern (step S3) wherein a threshold value is set at a fixed first value UL; a second inspection pattern (step S4) wherein a detection value X1 in an inspection zone 6 begins to increase, and the threshold value is set at a second value SL that is a determination value M1 plus the detection value X1 at the beginning of the increase; and a third inspection pattern (step S5) wherein the threshold value is set at a third value TL that is another determination value M2 plus the average Ave of the detection value X1 (n) at the point in time at which a can body 2 enters the inspection zone 6 and the detection value X1 (n+2) at the point in time at which the can body 2 leaves the detection zone 6. |
