Patent ID: 9613415
Date: 2017-04-04
CPC Classifications: G06T

Claim:
1. A protective film detecting apparatus for detecting whether or not a desired area of a work surface of a workpiece is actually coated with a protective film formed on the work surface of the workpiece, the protective film detecting apparatus comprising: a holding table for holding the workpiece in a condition where the protective film is formed on the work surface of the workpiece; droplets forming means for forming droplets on the work surface of the workpiece held on the holding table; light applying means having a light source for emitting light to apply the light to the work surface of the workpiece held on the holding table; imaging means for imaging the work surface of the workpiece; image storing means for readably storing an image obtained by the imaging means; image processing means for processing the image stored by the image storing means; and detecting means for detecting an uncoated area where the protective film is not formed, by using a difference in light intensity between a coated area where the protective film is formed and the uncoated area where the protective film is not formed to cause the formation of asperities due to the droplets formed on the work surface of the workpiece by the droplets forming means and the occurrence of Mie scattering of the light applied from the light applying means to the asperities, the difference in light intensity being detected from information on the image obtained by the imaging means and from the result of processing by the image processing means.