Abstract: A direct in-process measurement of the bottom kerf width uses a hardware, vision, and software system which captures a direct image of this kerf, computes its average width over a prescribed length and presents the data for visual observation, automatic control, and/or recordkeeping. In addition, by expanding the system to a measurement of the width of the top of the kerf, the verticality of the kerf may also be determined. In the preferred embodiment, a laser-cutting head produces controlled width kerfs in a sheet of plywood according to a preprogrammed pattern. A video camera is mounted relative to the cutting head and is held by a positioning system that is programmed to follow behind the cutting process and directly over the kerf. The optics of the camera are adjusted to view through the kerf and are focused on the bottom of the kerf which is backlit by a subsurface lighting system mounted in the corners of the tub on which the dieboard is mounted.

Abstract: A laser-machining apparatus that utilizes "flying optics" having at least one lens that corrects the divergence of the laser beam as it is emitted from the laser. Without correction, "flying optics" type of systems cannot be used with materials requiring a kerf that must be kept within tolerances not exceeding a couple of thousandths of an inch. The preferred embodiment utilizes a vertical lens that focuses the beam on the surface of the work piece. An additional adjustment of the vertical position of that lens is provided that corresponds to the distance that the carriage is from the laser and degree of divergence experienced with the laser that is being used. An alternative embodiment places at least one beam adjustment lens between the laser and the redirecting mirror that redirects the beam from the laser onto the surface of the work piece. In this embodiment, adjustment of the vertical lens to compensate for the laser beam divergence is unnecessary.

Abstract: An optical encoder housing is rotatably mounted upon a hub secured to the shaft of a motor typically by a set screw. The hub also carries the encoder disc. A circular leaf spring is fastened by studs to the motor housing and the encoder housing. Alternatively a spring couples the hub to the motor shaft while the encoder housing is secured to the motor housing.