Abstract: The present invention provides a system for image-capturing devices, such as scanners, to accurately identify defects in objects. The objects can be the physical images to be captured or elements of the image-capturing devices such as the platen and mirrors. The image-capturing devices can then use this defect information to remove defects from captured images. The invention teaches an advantageous arrangement of illumination and sensor elements to record defect data at an angle roughly equal to the angle at which light is directed to an object, i.e. where the angle of reflection roughly equals the angle of incidence. Light reflected from surface defects has a wider diffusion and thus a lower amplitude than light reflected from the surface of the object itself. Accordingly, this characteristic can be utilized to identify defect information.

Abstract: A method and apparatus utilizing one or two cameras are described for visually inspecting a polygonal component located at the end of the robotic end effector for determining presence, position and orientation of component leads prior to placement. Image processing improvements are provided for decreasing computational complexity by representing two dimensional image areas of interest, and each containing leads along one side of a component, by one dimensional summation profiles.

Abstract: The apparatus of the present invention may be utilized for the automated bonding of electronic components to a circuit board. A placement and bonding head is attached to a manipulatable robotic arm and is utilized to select an electronic component having a plurality of conductive leads from a supply of such components and position that component adjacent a plurality of contact pads on a circuit board. While retaining the electronic component within the placement and bonding head, the component is then thermally bonded to the contact pads. In one embodiment of the present invention, an electronic component may be optically inspected while being retained within the placement and bonding head. In another embodiment, thermal bonding is accomplished utilizing a plurality of thermally activatable blades which each include a thermocouple mounted adjacent thereto.

Abstract: A method and apparatus for minimizing escapement positioning error by matching the move sequence of a print carrier to the mechanical system dynamic characteristics without the use of a feedback sensor are described. A plurality of constant velocity signals are provided for driving the print carrier to the next print position. The sequential velocity signals comprise an acceleration velocity signal and a deceleration velocity signal, the duration of which are dependent upon the damped natural frequency of the print system. For long escapement moves, a slew velocity command is provided between the acceleration and deceleration velocity commands so as to maintain the velocity of the print carrier at the amplitude it had attained at the conclusion of the acceleration velocity signal. The relative amplitudes of the acceleration, slew and deceleration velocity signals are a function of the damping ratio of the printer system.

Abstract: A servomotor drive system for a printer escapement is provided which minimizes power supply requirements. The drive system has means for accelerating and decelerating the printhead escapement having a fixed current source applied to a servomotor which drives the escapement. In order to minimize power requirements, the system includes means for controlling the current in the motor which comprise means for sensing the actual motor current and feeding back the sensed current to a comparing means. A preselected varying current profile is applied to the comparing means which compares this profile to the actual motor current. Means are then provided responsive to these comparing means for altering the actual motor current to conform with this preselected varying motor current profile.

Abstract: A serial printer is provided which moves the printhead at optimum velocity with respect to the document being printed so as to achieve maximum throughput. Prior to the printing of each line of alphanumeric characters, the printer contains means for determining the length of said line. In response to said determined line length, drive means move the printhead across the medium at a selected velocity which is based upon the determined line length. The present expedient is particularly applicable to matrix printers wherein the selected velocity is constant during the actual printing of the line.

Abstract: A rotational shaft home position sensing transducer is provided which comprises a rotor mounted on the shaft having a planar surface with a first radial array of conductive elements on the surface in combination with a fixedly mounted stator having a planar surface parallel to the planar rotor surface and a second corresponding radial array of conductive elements on the stator surface adjacent and spaced from the first array. The structure further contains a unit for applying an alternating electrical signal to the first array of elements and a unit connected to the second array of elements for sensing the capacitive effect induced in the second array by said electrical signal. The first and second arrays must be arranged so that a single home position in the relative motion between the rotor and stator will induce a single unique capacitive effect in the second plurality of elements.