Abstract: An engraving head apparatus and method for engraving a gravure cylinder is shown. The engraving head apparatus includes a magnetostrictive actuator formed from a magnetostrictive material such as Tb.sub.1 Dy.sub.1-x. which elongatably drives a diamond-tipped stylus arm in a reciprocal manner in response to a varying magnetic field created by a bias coil and a drive coil. A cryogenic cooling mechanism is used to cool the magnetostrictive actuator when driving the stylus.

Abstract: A method and apparatus for automated loading, unloading and registration of a cylinder in an engraver. The method and apparatus permit the engraver to accommodate cylinders of differing geometries, including a range of lengths, diameters and mounting configurations. The engraver includes a headstock and a tailstock which cooperate to rotatably support a cylinder at an engraving station in the engraver. The engraver also includes a cylinder handling system having at least one cylinder support for supporting the cylinder between the headstock and tailstock during loading and unloading of the cylinder. The cylinder handling system is responsive to at least one parameter, such as a cylinder diameter, to automatically register the cylinder at the engraving station. In one form, the cylinder supports each include telescoping support member having a support nest for engaging and supporting the cylinder at the engraving station.

Abstract: A cylindrical engraving system selectively able to engrave in a helical and a circumferential format. An encoder scans index markings on the surface of a cylinder being engraved and generates timing pulses for selective application to one or the other of a helical drive unit or a circumferential drive unit incorporated within the system controller. Engraving is performed by an engraving head which is stepped in the axial direction along the workpiece in response to step pulses generated by the selected drive unit.

Abstract: A method and apparatus for engraving wherein the engraver includes a merge system for merging image data to be engraved in a manner which will reduce or eliminate "halo" and/or "ghost" images. The method utilizes a processor in an engraver for creating image data comprising continuous tone data and line work data. The method further involves the steps of locating transition data corresponding to where the continuous tone data and line work data meet; and processing at least some of the image data to provide processed image data using the transition data located in the locating step. The engraver has an engraving bed; a headstock and a tailstock located on the engraving bed for rotatably supporting a cylinder to be engraved; an engraving head located on the engraving bed for engraving the cylinder; an image data generator coupled to the engraving head, the image data generator being capable of creating image data comprising continuous tone data, line work data and transition data.

Abstract: This invention relates to an engraving method and apparatus for engraving a cylinder for printing an intaglio pattern on a web of material. The engraver comprises a driver for rotatably driving the cylinder and a computer for controlling the operation of the engraver and for generating an intaglio engraving signal corresponding to the predetermined intaglio pattern. The engraver also comprises an engraving head comprising a stylus having a generally flat cutting edge or surface. The engraving head also is capable of engraving at response times of less than 200-300 microseconds, thereby enabling the engraving head to engrave the intaglio pattern on the cylinder during the rotation of the cylinder in response to the intaglio engraving signal. The apparatus and method also comprise a fine line boost routine for facilitating engraving fine areas or lines of the intaglio pattern. There is also provided apparatus and method for controlling ink flow in large engraved areas or intaglio trenches.

Abstract: An engraving system for engraving printing cells in a gravure printing cylinder uses a video camera for feedback control of printing cell width. A setup procedure for the engraving system involves engraving an isolated test cell and a series of adjacent test cells, the latter being engraved under steady state engraving conditions. The isolated test cell is located through a search sequence which establishes a strobe control count for a strobe trigger unit. The strobe control count then is adjusted for steady state engraving by acquiring and centering a steady state test cell. Cell width is measured by creating video runtable sets for a plurality of overlapping video boxes and finding a maximum connected run length which meets predetermined acceptance criteria.

Abstract: An engraving head apparatus and method for engraving a gravure cylinder. The engraving head apparatus including a magnetostrictive actuator formed from TERFENOL-D.TM. which elongatably drives a diamond-tipped stylus arm in a reciprocal manner in response to a varying magnetic field created by a bias coil and a drive coil. The bias coil establishes a DC biasing magnetic field which causes an initial expansion of the actuator to approximately one-half the total linear expansion limit of the actuator. The drive coil is concentrically interposed between the actuator and the bias coil and modulates the magnetic field intensity established by the bias coil to cause additional expansion and contraction of the actuator about the initial expansion point.

Abstract: This system and method relates to an engraving system and method for engraving a pattern using a plurality of engraving devices. The engraving system discloses apparatus and method for sequencing and engraving of the plurality of engraving devices such that when the areas engraved by those heads meet to provide a continuous engraved pattern. The system and method utilizes an imaging system for imaging the engraved areas associated with each engraving head so that the heads or signals driving the heads may be adjusted to further facilitate providing engraved areas which appear as if they had been engraved by a single engraving head when, for example, the engraved area of one head meets the engraved area of another head. Also, disclosed is a method for sequencing and transmitting image data associated with an image to be engraved in order to accommodate any cylindrical offset or the angular displacement between, for example, two engraving heads that are positioned in a generally opposed relationship.

Abstract: The engraving method and apparatus provides a method and apparatus for engraving a plurality of cells in a surface of a cylinder. The engraving method and apparatus involves, among other things, processing a plurality of image data; modifying at least a portion of the image data and generating a signal corresponding thereto; and then exciting an engraving device in response to the signal in order to engrave a pattern of engraved areas. The engraving method and apparatus facilitate adjusting a characteristic of at least one of said plurality of engraved areas in order to change a spatial relationship between said at least one of said plurality of engraved areas and another of said plurality of engraved areas to provide, for example, a non-regular or non-periodic spacing of engraved areas.

Abstract: An automatic self-centering chuck system for use on an engraver. The chuck system includes a plurality of jaws which are slidably mounted for movement in a radial direction toward a central aperture of the chuck to clamp a shaft for an engraving cylinder. Each of the jaws is actuated for movement by a lever pivotally mounted within the chuck. The levers are actuated for pivotal movement by an axially reciprocating drawbar which is energized for movement by a series of pneumatic cylinders. The components of the chuck are accurately machined to provide close tolerance, precise movements of the jaws whereby a cylinder will be accurately positioned at the central rotational axis of the chuck. In order to ensure that the precise level of jaw movement is maintained throughout the life the chuck, a lubricant flushing or purging system is provided for flushing normal wear particles from the precision components internal to the chuck.

Abstract: A method and apparatus for automatically measuring a cylinder characteristic, such as a cylinder diameter or a cylinder run-out and then automatically adjusting the engraver in response to the measurement and subsequently engraving the cylinder to account for such characteristic. The engraver includes a run-out detector for detecting a cylinder characteristic of the cylinder on the engraver, and the run-out detector includes an LVDT sensor and a run-out circuit for generating a signal generally corresponding to a shape of the cylinder surface. The run-out circuit is capable of generating a measured run-out using the signal generated by the LVDT sensor. The invention also provides a method and apparatus for automatically adjusting for the cylinder characteristic using manual, mechanical and/or electronic features of the invention.

Abstract: The invention provides a method for controlling the engraving head and the response of the engraving head in response to a plurality of engraving setup parameters which may be input into a computer associated with the engraving head and automatically generating a response signal for energizing the engraving head in response to the plurality of engraving setup parameters which were input in real units. The method further provides that adjusting one or more of the engraving setup parameters in real units may be performed. Further, the method provides for multiplying either an AC input signal or a video signal by a multiplication factor which is generated by the setup circuit to produce the driving signal.

Abstract: A computer controlled engraving system having a non-volatile memory loaded with error coefficients. The error coefficients represent previously experienced differences between computed cell configuration values and corresponding configuration values for cells actually engraved. Sets of error coefficients are tabulated and stored in the memory along with associated setup parameters. Setup of the engraving system for a new job is swiftly accomplished by using values of the setup parameters to retrieve sets of approximate error coefficients, from which interpolated values are obtained. The interpolated values of the error coefficients then are used for calculating configuration control parameters such as AC gain, video gain and white offset.

Abstract: A method and apparatus for automated loading and unloading of a cylinder in an engraver. The method and apparatus permit the engraver to accommodate cylinders of differing geometries, including a range of lengths, diameters and mounting configurations. The engraver includes a headstock and a tailstock which cooperate to rotatably support a cylinder at an engraving station in the engraver. The engraver also comprises a cylinder handling system having at least one cylinder support for supporting the cylinder between the headstock and tailstock during loading and unloading of the cylinder. In one form, the cylinder supports each comprise a telescoping support member having a support nest for engaging and supporting the cylinder at the engraving station. In another form, the cylinder supports each include a support housing and a support structure mounted to the support housing. In this form, the support structure includes at least one cylinder receiving area.

Abstract: A cylindrical engraving system selectively able to engrave either in a helical or circumferential format. An encoder scans index markings on the surface of a cylinder being engraved and generates timing pulses for selective application to one or the other of a helical drive unit or a circumferential drive unit incorporated within the system controller, Engraving is performed by an engraving head which is stepped in the axial direction along the workpiece in response to step pulses generated by the selected drive unit. The step pulses may be generated in spaced bursts or at a regular frequency depending upon whether circumferential or helical driving has been selected.

Abstract: This invention relates to a method and apparatus for linearizing engraving cells to be engraved in order to adjust for visual discontinuities. An engraver for engraving a cylinder comprises a controller having data stored therein. The data generally corresponds to at least one line of cells to be engraved on the cylinder. The engraver also comprises an engraving head coupled to the controller and operatively mounted in the engraver. The engraver further comprises means located in the controller for using filter criteria to selectively filter and linearize the data so that the controller can subsequently energize the engraving head to engrave the at least one line of cells so that it appears continuous.