To precisely observe a mark with satisfactory contrast, by an inexpensive device easily manufactured.
This lighting system for observing the mark 1 comprising a non-light-transmissive material embedded in an inside of an observed object 2 comprising a light-transmissive material is provided with a light diffusing means 3 arranged with a light diffusing material on a face reverse to an observed face 2a of the observed object, a light irradiation means 4 for irradiating the observed object with light from an observed face side, and a light shielding means 6 arranged between the light irradiation means and the mark to shield the light emitted from the light irradiation means toward the observed face of the mark. In this lighting method, the light emitted from the light irradiation means is shielded not to be emitted from the observed face side to the mark, the light emitted from the light irradiation means is made to be emitted from the observed face side, and the emission light transmission-illuminates the observed object from a side contrary to the observed face, through the observed object and the light diffusing means arranged on the face reverse to the observed face of the observed object.
UNO MASAHIKO
KANEDA MITSUHIRO
IKEMI ATSUSHI
Tadahiko Inaba
Kanako Murakami
Nakatsuru Kazutaka