AIR TIGHTNESS TEST METHOD AND AIR TIGHTNESS TEST DEVICE FOR SEALED BATTERIES.

摘要

A soft-packaged sealed battery is placed in a sealed container. The pressure in the sealed container is reduced, and the shape of the undulations on the surface of the sealed battery in the sealed container is imaged using a CCD camera, or the like, before and after reducing the pressure. An assessment as to whether the air tightness of the sealed battery is being maintained is made on the basis of changes in the shape of the undulations on the surface that appear as differences in the brightness of the pixels, for example, of the captured image. The impact of fine creases, which cannot be seen by the eye, on the surface of the sealed battery on the assessment is eliminated, and a highly accurate air tightness assessment is achieved by this assessment method.