Abstract: In a device having a driving mechanism for moving a writing medium over a platen disposed adjacent the mechanism and having a generally horizontal table portion and a curved outer portion where the writing medium is smoothly curved from a generally horizontal supported state to an unsupported vertically hanging state an improvement to the platen for eliminating static charge buildup problems. In its simplest form, it comprises a plurality of horizontal grooves in the upper surface of at least the curved outer portion of the platen at spaced intervals. Preferably, the plurality of horizontal grooves are substantially V-shaped in cross-section so as to create, in effect, a series of overlapped plates on the surface of the platen which, in turn, cause the creation of areas of air turbulence which partially support the moving medium.

Abstract: An apparatus which records an image, such as text, onto printable media, such as paper, has a removably closable lid, a paper cutting blade mounted on an pivoting arm having an equilibrium position in which the blade is withdrawn in a safe position, and a rod actuator cooperative with the lid for rotating the pivoting arm whenever the lid is closed so as to move the blade from the safe position to an operative position adjacent a cutting block suitable for severing the media. The pivoting arm is rotatable about a pivot pin, the blade being attached at one end of the arm and the other end of the arm being lighter, so that the blade tends to fall toward the safe position under a front cover of the apparatus whenever the lid is opened.

Abstract: A low-friction, low-play bearing system for use in a carriage coupling drive system for a pen plotter including a moving carriage slidably mounted on a shaft between the ends of and carrying a U-shaped pen-carrying yoke in combination therewith for sliding motion along the shaft and rotary motion about the shaft. A pair of annular ball-bearing thrust bearings are disposed over the shaft between respective ends of the U-shaped yoke and the moving carriage. An annular bias spring such as a wave spring is disposed over the shaft between the moving carriage and one of the thrust bearings to create a longitudinal expansion force resisting play between the moving carriage and the U-shaped yoke.

Abstract: A digitizer tablet and associated method of construction employing ink-on-glass technology. The method comprises first obtaining substrate having top and bottom surfaces. A plurality of parallel, spaced conductive ink first conductors are applied on the top surface of the substrate with the first conductors terminating in conductive ink pads adajcent a side edge of the substrate. A plurality of parallel, spaced conductive ink second conductors are then applied on the bottom surface of the substrate perpendicular to the first conductors with the second conductors terminating in conductive ink pads adjacent another side edge of the substrate. A flexible connector strip containing a plurality of flexible conductors terminating in conductive pad ends is then placed with the pad ends over respective ones of the conductive ink pads and an electrically conductive adhesive tape is placed between respective ones of the conductive pad ends and the conductive pad end's associated the conductive ink pad.

Abstract: A method and apparatus for providing platen mapping for known clearance pen movement in a graphics plotter system having a platen over which paper is moved longitudinally to create one axis, penholding apparatus moved transversely across the platen and the paper to create the other axis, and a controlled raising and lowering mechanism connected to the penholding apparatus for lowering a pen being held therein into contact with, for raising it from contact with the paper, and for providing a relative vertical position value signal. Vertical sensing apparatus is connected to the penholding apparatus for sensing the top surface of the platen. First logic is operably connected to the vertical sensing appartus and to receive the vertical position value signal from the controlled raising and lowering mechanism for calculating and saving a plurality of deviation values indicating the distance deviation of the platen top surface from parallel at a plurality of spaced points across the platen.

Abstract: A shield for use in eliminating edge effects from an electromagnetic digitizer having an active area of a grid of wires surrounded by a peripheral area of connecting wires containing sensitive interconnecting circuitry. The shield is a pan-shaped shield of a non-ferrous metal sized and shaped to fit over the underside of the grid of wires and surrounding area of connecting wires. The shield comprises a center section disposed over the active area of the grid wires and spaced from the active area so as to provide no interference with the operation thereof and an outer peripheral shielding lip that is disposed in close-spaced, non-contacting relationship to the areas of sensitive interconnecting circuitry contained within the connecting wires. The preferred shield is formed of a single blank of aluminum sheet having peripheral edge portions thereof bent into non-connected, abutting relationship at corners thereof to form the outer peripheral shielding lip.

Abstract: A humidifying system for maintaining the moisture content of the paper at a preferred level in an electrostatic plotter. The plotter has a paper supply compartment rotatably holding a horizontal roll of plotting paper where the paper passes from the roll and through the supply compartment to a separate printing compartment. There is a powered piezoelectric humidifier for supplying cool water vapor at an outlet opening thereof. An adjustable humidistat is disposed in the paper supply compartment and operatively connected to turn the humidifier on and off as a function of the humidity in the paper supply compartment. A plastic pipe manifold is horizontally disposed across the inside of the paper supply compartment. The manifold has a closed end and an opposite end connected to the outlet opening of the humidifier. The manifold has a plurality of spaced outlet holes through sidewalls thereof along the length thereof for water vapor introduced into the manifold by the humidifier to emerge therefrom.

Abstract: An improvement to graphics pen plotters including a pen gripping mechanism for gripping a cylindrical bodied pen in a generally vertical orientation for sensing the presence and type of a pen in the gripping mechanism with a single sensor. There is a multi-channel sensor adapted for producing and sensing a plurality, "n+1", of parallel light beams disposed one above the other to produce a binary number at an output thereof indicating the ones of the light beams sensed by the sensor. The sensor is disposed to shine the light beams at a position past which the pen is moved by the gripping mechanism. There is also a cylindrical reflective surface disposed about a portion of the body of the pen so as to be struck by the light beams when the pen is being gripped by the gripping mechanism at the position and reflect the light beams back towards the sensor to be sensed thereby.

Abstract: A method and apparatus for routing, holding, and hiding cables associated with electronics devices. The preferred embodiment is an extrusion for application to a surface of an electronics device or incorporation into the framework thereof defining a groove capable of routing, holding, and hiding the electrical cable(s). The extrusion has a cross-section comprising a plurality of sides connected to one another to define a desired shape for the extrusion. A pair of the sides have a generally V-shaped orientation with respect to one another thereby forming a longitudinal slot in the extrusion capable of containing the cable therein. The slot-forming pair of sides each includes opposed portions comprising a plurality of adjacent V-shaped segments thereby forming opposed longitudinal teeth in the sidewalls of the slot capable of releasably gripping a cable disposed in the slot.

Abstract: An improvement to position digitizing devices wherein sensed response voltages caused by the interaction of a movable instrument relative to conductors beneath a planar surface are converted to digital form and digitally processed to determine instrument position. An integrating voltage to frequency converter is used to produce a frequency with a correspondence to the voltage applied to it. By counting the frequency for a defined length of time, a resultant count is obtained which also corresponds to the applied voltage. By varying the counting period under microprocessor control, acquisition rate and resolution can be varied over several orders of magnitude without changing circuit components. The digitizer includes conductive elements disposed across the digitizing surface and incorporated into an instrument for producing an analog voltage signal having a DC component related to the position of the instrument on the digitizing surface.

Abstract: An electronic pen for a digitizer capable of providing signals to a computer for pen movement in three dimensions relative to a planar tablet. There is a hollow, pen-shaped body member having a writing tip end. A sensing coil is disposed in the body member adjacent the writing tip end and having wires thereof connectable to the computer for use in developing X- and Y-axis positional signals relative to movement of the writing tip end over the surface of the tablet. A pen member is disposed in the body member for longitudinal slidable movement within the body member. The pen member has a writing tip passing out through the body member at the writing tip end and an opposite inner end. Finally, there is a linear position transducer disposed within the body member for producing on output wires therefrom connected to the computer Z-axis positional signals relative to the pressing of the writing tip end against the surface of the tablet.

Abstract: A new design for electrostatic printheads, and the like, which can be formed quickly, easily, inexpensively, and reliably employing wire bonding techniques. The preferred method disclosed is a method for simultaneously making two electrostatic printhead portions each having a row of dot-producing conducting printwire ends at a planar print face. A pair of printed circuit boards containing a plurality of parallel, spaced, flat, conductor strip ends along edges thereof are disposed in a common plane with the conductor strip ends positioned opposite one another in paris. Connecting wires are then wire bonded between the pairs of strip ends. The connecting wires are then embedded in an insulating material which will adhesively bond to the printed circuit boards along the edges thereof and cure into a hard material forming the body of the resultant printhead elements.

Abstract: A method and apparatus for providing automatic paper edge finding and sizing in a graphics plotter system having a platen over which paper is moved longitudinally to create one axis, penholding apparatus moved transversely across the platen and the paper to create the other axis, and a controlled raising and lowering mechanism connected to the penholding apparatus for lowering a pen being held therein into contact with, for raising it from contact with the paper, and for providing a relative vertical position value signal. Vertical sensing apparatus is connected to the penholding apparatus for sensing the top surface of the platen. First logic is operably connected to the vertical sensing apparatus and to receive the vertical position value signal from the controlled raising and lowering mechanism for calculating and saving a plurality of values indicating the distance to the platen top surface at a plurality of spaced points across the platen.

Abstract: A digitizer wherein the transduction frequency is controlled (automatically or manually) to minimize the interference effect of sources of external AC fields, such as CRT monitors. The digitizer implements the method of operation comprising the steps of, connecting a source of a frequency higher than the frequency to be employed as the transduction frequency of the digitizer to the first input of a counter; receiving input pulses from the source at the first input of the counter; outputting output pulses which are employed to generate the transduction frequency in the digitizer at an output of the counter; selectively setting an initial count value at a second input of the counter; and, repeatedly counting from the initial count value at the second input to a terminal value, outputting an output pulse upon reaching the terminal value, and resetting to the initial count value after outputting each output pulse.

Abstract: A pen type sensor for use in a graphics pen plotter wherein plotter pens are moved along a pre-established path between a pen holding area and a plotting area for reading a plurality of vertically oriented reflective indicia positions thereon to create a binary logic output signal representative of the pen type. There is a hollow body member having a pair of angled front surfaces. Light emitting apparatus is associated with one of the pair of angled front surfaces for directing a light beam to simultaneously strike the indicia positions at a point on the path of pen movement. A plurality of light detectors are associated with the other of the pair of angled front surfaces for receiving on respective sensing surfaces thereof the light beam as it is reflected by reflective indicia on a pen at respective ones of the positions and for creating respective bi-stable output signals reflecting the presence and absense of reflected light on the sensing surfaces.

Abstract: Apparatus for accurately raising and lowering the pen and for generating a positional signal for control use in a graphics plotter having a penholding mechanism slidably and rotationally mounted on a beam for longitudinal positional movement along the beam and rotational movement around the beam to affect raising and lowering of a pen held by the penholding mechanism under the control of plotter control logic. There is an actuator rod disposed parallel to the beam for rotational movement about a longitudinal axis. A spring biases the penholding mechanism to the raised position. A ball bearing linkage is provided for smoothly and slidably linking the actuator rod to the penholding mechanism so that as the penholding mechanism is smoothly moved longitudinally along the beam, rotation of the actuator rod will cause corresponding rotation of the penholding mechanism towards the lowered position.

Abstract: In a graphics plotter having motor control logic for controlling a motor employed in the process of drawing a series of vector lines comprising a plot, an improvement to the logic for applying optimum control of the motor. The length of each next vector to be drawn is first calculated. The logic for controlling the motor is then self-adjusting as a function of whether the next vector line to be drawn is a short-length vector less than a pre-established length or a long-length vector longer than said pre-established length.

Abstract: Methods and apparatus for forming an electrostatic printhead. The basic printhead member if formed by casting an insulating material around a plurality of side-by-side spaced wires. One side of the insulating material and the wires are cut off to form a printhead face. The other side of the insulating material and the wires are cut off to form an attachment face with the wire ends exposed. A printed circuit board having electrical contacts along the edge is positioned adjacent the exposed wire ends of the attachment face and the wire ends are wire bonded to the contacts. In one embodiment, there are two printed circuit boards positioned on either side of the attachment face and then folded together following the wire bonding. In another embodiment, the attachment face is formed as ledges having the exposed ends of the wires cut as rectangular pads for more area of attachment and the insulating material is attached to the edge of a single printed circuit board.

Abstract: A multicolor electrostatic plotter is disclosed and includes an image head for imparting a charge pattern to a web medium to be imprinted and a plurality of toner means associated with different colors in which different colors are successively applied to portions of the medium by repeatedly driving and rewinding a portion of the medium past the image head and the plurality of toner means for charge and toner application to imprint multiple color rasterized images on the medium by the use of electronic circuitry which imprints a reference track on the medium during the first color pass and then optoelectronically detects deviations, generally perpendicular to the directional movement of the medium, of the medium during successive color passes substantially instantaneously with the deviations and which electronically adjusts the input data from a remote rasterizer by an amount equal to the substantially instantaneous offset so that lines of raster data are shifted by an amount substantially equal to the instan