lamp item 6 b the front illumination is required to identify surface imperfections i e chipped or broken sections of tools not identified using only the backlight technique the image sensor transfers data to the image processor item 9 via a high speed video link item 8 the high speed video link can be one of several available formats i e fire wire camera link digital or analog eia rs 170 the image processor item 9 and special image processing software item 10 are used to analyze the image data the image processing power required for the inspection task depends on the size of the images to be analyzed and the time between tool changes the tool change operations are usually very long compared to the image acquisition processing time the specialized image processing software will determine if the cutting tool is acceptable for use before it will allow the next machining operation to proceed the second btds configuration fig2 is a more sophisticated configuration and provides a linear translator item 11 to move the image sensor attached to a moveable stage bracket item 12 this configuration is required when the cutting tools used in the cnc machining center exhibit large variations in length the btds would be instructed as to the location of the cutting tool 39 s end point when they are initially loaded into the automatic tool changer the linear translator will move the image sensor parallel to cutting tool axis and insure that the end point tip of drill or tap is positioned within the field of view the btds can also utilize an led ringlight item 13 for front lighting of the cutting tool in place of high frequency fluorescent lighting item 6 a amp 6 b the led.