Abstract: An actuator mechanism for a plotter carriage adaptable for use in either a pen plotter or a pencil plotter mode in which a coupler engages both a support for a pen holder and a support for a lead holder and a motor and an actuator arm coupled to the motor are provided for driving the coupler relative to a drawing media surface. An interlock and a sensor are provided to enable the motor, actuator arm and coupler to be coupled to a pencil actuator mechanism and to determine whether the plotter carriage is being used in a pen plotter or a pencil plotter mode.

Abstract: A pen force gage for a pen plotter for determining whether the force of a pen positioned by a pen support onto the surface of a drawing media in the pen plotter falls within an acceptable range. The pen force gage includes structure for aligning or positioning the gage within the pen plotter so as to enable the gage to measure the force of the pen; a pivotable arm configured at one end to interact with the pen support as the pen moves toward the surface of the media and at the other end to support a movable weight to determine the force to be applied by the pen on the surface of the media; and an indicator and a reference mark for determining whether the force falls within the acceptable range.

Abstract: A lead loader mechanism for a pencil plotter in which a lead stocker contains a plurality of leads for use in a pencil plotter, at least one lead actuator mechanism is coupled to the lead stocker and is adapted to release the leads, and a support is provided for holding at least one lead holder and for engaging the lead actuator mechanism to release the leads into the lead holder. In a particular embodiment, the lead stocker has at least one lead storage chamber therein and the lead actuator mechanism is mounted on the lead stocker below the lead storage chamber and is adapted to be changed from a first condition in which the leads are prevented from leaving the lead storage chamber to a second condition in which the leads are free to leave the lead storage chamber, and the support is adapted to cause the lead actuator mechanism to change from the first condition to the second condition.

Abstract: A media loader for a media roll having a pair of endcaps. The media loader has a handle portion, a support portion adapted to partially encircle the endcap and a flexible midportion having an opening narrower than a selected portion of the endcap and adapted to flex to allow the passage therethrough of the selected portion of the endcap. The support portion is substantially the same cross-sectional size as the selected portion of the endcap but is adapted to remain stationary when the endcap rotates therein. The handle portion is adapted to accept therethrough portions of the endcap of larger cross-sectional size than the selected portion of the endcap while the flexible midportion is sufficiently stiff so as not to flex under the weight of the media loader.

Abstract: A lead positioner for a pencil plotter in which a lead stocker contains a plurality of leads for use in a pencil plotter, a lead actuator mechanism is coupled to the lead stocker and is adapted to release the leads into a lead holder, and a shaker is provided coupled to the lead stocker and adapted to enable the leads to be released individually into the lead holder. In a particular embodiment, the shaker imparts a vibrational motion to the lead stocker prior to the lead actuator mechanism releasing the leads to enable the leads to be released individually. The shaker is further adapted to provide a translational motion to the lead stocker to align the leads and the lead holder and, in addition, to enable the lead actuator mechanism to release the leads into the lead holder.

Abstract: An ink sensing system for a vector plotter in which a pen is adapted to be raised and lowered from a drawing media surface along a system axis. An optical detection system is provided which has a focal point on the system axis and below the media surface when the pen is in its lowered position and at the media surface when the pen is in its raised position. The optical detection system includes a source of illumination and a detector system to determine the degree of reflectance from the media surface to indicate the presence or absence of ink on the media surface. In a particular embodiment the optical detection system is moveable and the movement of the optical detection system is coupled to the movement of the pen. Furthermore, the focal point of the optical detection system coincides substantially with the last point of contact of the pen with the media surface when the pen is in the raised position.

Abstract: The method of manufacturing an electrostatic printhead or the like. Conductive surfaces are applied to both sides of an insulating substrate. Unneeded portions of the conductive surface are etched away by a photolithographic process to form conductive layers in patterns of parallel, spaced, printwire traces and connective conductors with ends of the printwire traces terminating in a common plane defining a printface of the printhead. Additional conductive material is added to the printwire traces by an additive plating process to give them a substantially square cross-section. The edge is laser trimmed to form the print face. Insulative layers are added over both sides with vias located over the connective conductors at places where electrical connection is to take place.

Abstract: A method and associated circuitry for use in an electromagnetic digitizer having a plurality of first grid conductors connected from a first multiplexer controlled by a first enable input to ground and a plurality of second grid conductors connected from a second multiplexer controlled by a second enable input to ground and crossing over the first grid conductors at multiple points for eliminating errors caused by capacitively coupled signals between the grid conductors at the cross over points.

Abstract: An assembly for positioning a print head so as to transfer ink from an ink ribbon to a printing medium positioned on a movable platen adjacent to said ribbon supports the print head on a rocker member which enables the head to be swung between a print position wherein it engages the ink ribbon and a feed position wherein the head is spaced from the ribbon enabling ribbon to be moved. The rocker is rocked to move the head between its two positions by a rotary cam driven by a small low-power electric motor. When the cam engages the rocker member at selected angular positions, the head is maintained in its retracted feed position; otherwise, the head resides in its print position. The assembly also includes provision for detecting the angular position of the cam so as to produce signals to facilitate repositioning the cam and head promptly.

Abstract: A cutter assembly (82) for cutting web material such as paper (80) includes a circular cutter (100) having an endless peripheral blade (102) mounted on a frame (92) on which also is mounted a tension roller in the form of a pulley (94). A smaller pulley (98) is mounted on and co-axial with the circular cutter 100, and a belt (96) is trained around the pulleys (94 and 98). The portion of the belt (96) on the tension roller (94) provides an engagement surface adapted to engage the paper (80) so that movement of the cutter assembly (82) causes rotation of the tension roller (94) and thus faster rotation of the circular cutter (100). This results in efficient cutting of the paper (80) and high cut quality because the tension roller (94) prevents bunching of the paper (80) in the vicinity of the endless blade (102).

Abstract: A control system for controlling a turret head in a pen plotter wherein the turret head and pen holder move in combination with the pen carriage to provide turret selectability at the writing site. Sensors and associated logic are provided for detecting the presence of a turret on the pen carriage, for sensing the presence and absence of pens in the turret and in the pen holder, for detecting the type of pen or other writing device being used and taking appropriate action responsive thereto, and for applying varible damping constants to the movement of the turret head. Control logic is disclosed for assuring reliable and optimum operation.

Abstract: A user-friendly ribbon cartridge to house and to facilitate handling a wide thermal transfer ribbon for a thermal color printer is composed of first and second casing sections which define a slotted let-off tube and a slotted take-up tube and turnbar. A pair of casing end pieces connect the corresponding ends of the casing sections so that they are juxtaposed with their axes parallel to one another so as to define a plane and the turnbar is spaced parallel to that plane so that a stretch of ribbon wound about cores rotatively mounted in the tubes can extend out through the tube slots and over the turnbar creating a large unobstructed planar ribbon area that is accessible from both sides for printing. A handle and latch member integral to one of the end pieces facilitate positioning the cartridge properly in the associated printing apparatus and locking it in place during printing.

Abstract: In a sketch pad embodying the present invention, the sensing pad has an array of generally parallel pairs of adjacent sensing conductors which, for the purpose of this explanation, will be condidered as extending in the horizontal or X direction. Each conductor has a generally triangular shape, with the base of the triangle at one edge of the pad and the apex at the opposite edge. The conductors in each pair are complementary, that is, their bases are at opposite edges of the pad. Preferably the stylus used with the sensing pad has an electrode at its tip to which it applies an alternating current signal at a frequency that is suitably high for capacitive coupling to the sensing pad. To ascertain the X position of the stylus on the pad, the right or left set of conductors is connected to sensing circuitry and the other of these two sets is grounded. The sensed voltage then corresponds to the X position.

Abstract: A signal-acquisition system (10) for a circular antenna array (12) includes a two-dimensional compressive receiver (18) that performs a two-dimensional Fourier transformation in time and position on the outputs of the array. Each of the outputs of the compressive receiver (18) is fed to input ports of several processing units (24), which multiply them by an appropriate time-dependent function. The resultant modified signals are then processed by Butler matrices (30) that together have a matrix of output ports (32). Each output port is associated with a different combination of azimuth and elevation angles. A signal source at given azimuth and elevation angles with respect to the array (12) causes its greatest response in the output port (32) associated with those angles.

Abstract: A flexible circuit (28) containing the grid connectors of a digitizer tablet (10) converge in a transition region (48) disposed in an unshielded area. However, the positional inaccuracies that would otherwise result from the exposure of the non-parallel conductors to radiation from the tablet's stylus (24) are reduced because the flexible circuit (28) is kept in close proximity to a metal plate (32) throughout the transition region (48) in which the conductors depart from a parallel configuration.

Abstract: A pen capping mechanism for use in an X, Y graphics plotter, or the like, having a plurality of pens with writing tips requiring sealing between periods of use. A flat bar of plastic is provided as a slider member with an upper surface adapted to sealably mate with the tips of the pens. The slider member is supported for longitudinal movement on a support track and is moved between positions by an operator connected thereto. The member has a plurality of bores therethrough through which respective ones of the pen tips can pass in order to write. The bores are positioned such that as the member is moved through the various operative positions, respective ones of the bores come into alignment with a pen tip such that only one pen tip at a time is in alignment with one of the bores.

Abstract: A slitting apparatus employing safety features and particularly suited for use in slitting strip paper as employed in a graphics drum plotter. A housing is provided which is adapted to be releasably attached to the frame of the plotter adjacent the takeup roller for the strip paper. The housing has a box-shaped top with a hinged opening rear portion. A plurality of knife blades are mounted in housings disposed in a slot in the wall of the box portion for adjustability as to their position along the width of the paper. The knife blades are spring-biased to a retracted position and adjustable actuators in the hinged portion extend the blades selectably only when the box is closed. A releasable latch is provided for holding the box in a closed position. A releasable latching assembly connects the housing to the frame of the plotter. The latching assembly is activated by opening the box which, in turn, retracts the knife blades.

Abstract: A convertible platen for use in a graphics plotter to allow its selective use as either a cut paper plotter or a roll paper plotter. The platen is formed from a specially designed aluminum extrusion and a pair is mounted with one on either side of the drum of a drum plotter between the drum and the supply/takeup rollers. The platens can be raised and held adjacent the drum and spanning the vacuum columns in the plotter to create a table having curved outer edges to support cut paper. They can be released and dropped into the vacuum columns whereby they lie against the outer surfaces and form the upper inner wall with curved upper edges over which paper smoothly is guided between the vacuum columns and the supply/takeup rollers.

Abstract: A method for processing navigation signals received by a LORAN-C receiver to lessen the effects of noise on the navigation data provided to the receiver user. Time of signal arrival information measured by the receiver is modified depending on the signal-to-noise environment to remove extreme time of signal arrival deviations that are obviously erroneous. The modified information is then averaged to more accurately determine the true time of signal arrival and thereby provide more stable and accurate navigation data.

Abstract: A scanning system providing a linear scanning beam utilizing a fiber optic bundle, one end of which forms a circle which is scanned by a light beam and the other of which forms a straight line. Other fibers are within and external to the circle formed by the one end of the fiber optic bundle and are used to provide a feedback signal used to correct the scanning light beam to impinge only on the fiber ends of the one end of the bundle.