SELF-DIAGNOSING APPARATUS FOR SURFACE DEFECT DETECTOR

PURPOSE: To judge whether there is a functional trouble or not in a detecting part by comparing the crack information based on reflected light in the surface of a crack sample with the flaw information of a flawed sample stored previously. CONSTITUTION: When a standard forming mode of a self-diagnosis relating instruction means 75 is selected, a self-diagnosis control part 77 receives a signal of the means 75 and inform a detection part 51, a selector 61, and a signal processing part 62 of the setting of a standard formation. The detection part 51 starts driving the diagnosing mechanism part and sends the flaw signal to the processing part 62 through the selector 61, based on the reflected light on the surface of a flawed sample. After carrying out differentiation process for the flaw signal, the processing part 62 extracts the quantity of the characteristic of the flaw and stores the result in a standard memory 63. Then, when a self-diagnosis mode of the means 75 is selected, from the detecting part 51 to the processing part 62 operate in the same way and the quantity of the characteristic of a flaw is stored in a present time memory 65. The data of the standard memory 63 and that of the present time memory 65 are compared mutually and a data processing part 69 judges that a functional trouble does not exist (exist) in the detection part 51 if these is (is not) the identity of both data.