Patent ID: 8796628

Claim:
A method for inspecting sealing defects in a sealed portion of a container sealed planewise using infrared light, comprising: irradiating the infrared light in a wavelength range of 1450 nm±20 nm onto a sealed portion of a sample container from an outside of the sample container, which does not have a sealing defect and which includes a content therein, the sample container being sealed after being filled with the content; receiving the infrared light reflected from or transmitted through the sealed portion of the sample container at the outside of the sample container; outputting a voltage according to an amount of the received infrared light; converting the outputted voltage into an analog voltage value thereby setting a threshold based on the analog voltage value; irradiating the infrared light onto the sealed portion of a container to be inspected, which container is filled with the content and sealed, the infrared light being in a same wavelength range as is irradiated onto the sealed portion of the sample container and being irradiated from an outside of the container; receiving the infrared light reflected from or transmitted through the sealed portion of the inspected container at the outside of the container; converting the received infrared light into the analog voltage value as in the case of the sample container; and judging a sealing defect in case the analogue voltage value is smaller than the threshold.