Tool failure detection apparatus

摘要

In a tool failure detection apparatus for a working machine such as a drilling machine for circuit boards, light is irradiated onto a workable area of a workpiece, and reflection light from the workable area is picked up by an imaging unit to produce a video signal. A video signal indicative of at least either one of a tool image and a worked void image which is picked up within a predetermined region of a picture is sampled to calculate an image area. A comparator compares a calculated image area with a preset reference value indicative of normality of the tool to judge whether the tool is normal or broken.