To surely determine a sealing condition influenced neither by the transfer condition of an envelope medium nor by the twist, etc. of a flap.
This seal checking device includes a transfer mechanism 3 for transferring an envelope P sealed by folding and adhering a flap Pb integrally formed on an envelope main body Pa with the flap side in front, a detection part 5 for detecting the shape of the envelope P in the thickness direction along its transfer direction by laser scanning from the flap Pb side to the back end side of the envelope P transferred by the mechanism 3 and by receiving the laser light reflected from the flap Pb and the main body Pa and a determining part for determining the sealing condition from the shape detected by the part 5.
Satoshi Kono
Makoto Nakamura
Kurata Masatoshi
Takashi Mine
Yoshihiro Fukuhara
Sadao Muramatsu
Ryo Hashimoto