Fluorescent microscopy for 3-dimensional geometrical structure

3-D metrology using optical microscopies such as confocal, focus variation is highly demanded. However, they cannot measure smooth steep surfaces, vertical surfaces, so geometrical dimensions are only measured using contact-type instruments like CMM. This study proposes an optical 3-dimensional measurement technique using fluorescent signal, which is emitted over all-direction. Detecting the fluorescent light from the surface, it is possible to measure steep surface even vertical. It is possible to detect the fluorescent light from the overhung surface. 

M. Michihata, et al: “Sensing a vertical surface by measuring a fluorescence signal using a confocal optical system” Measurement science and technology, Vol.25 Issue 6 (2014) 064004.

doi: https://doi.org/10.1088/0957-0233/25/6/064004

Y. Takaya, K. Maruno, Masaki Michihata, et al, “Measurement of a tool wear profile using confocal fluorescence microscopy of the cutting fluid layer”, CIRP Annals - Manufacturing Technology, vol.65, issue 1 (2016) pp.467–470.

doi: https://doi.org/10.1016/j.cirp.2016.04.014

K. Maruno, M. Michihata, et al; “Fundamental study on novel on–machine measurement method of cutting tool edge profile based on fluorescent confocal microscope”, International Journal of Automation Technology, vol.10, no.1 (2016) pp.106-113.

​doi:  https://doi.org/10.20965/ijat.2016.p0106​

測定面から発せられる蛍光という信号を取得することで、光学的な手法を用いて3次元の形状を計測する手法を研究しています。通常、幅はどの幾何学的情報は、CMMなどの接触式の測定器でのみ測定可能でしたが、蛍光を共焦点検出することで、光を用いた幾何形状の寸法計測が可能となります。円筒を測定すると下図のように、90度までは正確に測定でき、90度以上のオーバーハングでも光が検出でき、今後の研究で正確な計測も可能性があります。