Abstract: A pointer position detection system for use in determining the position of a pointer relative to a tablet comprising a signal generating system coupled to the tablet for transmitting a driving signal, the signal generating system including a set of conductors for radiating the driving signal and the driving signal including information as to the particular conductor being activated by the signal generating system, a movable pointer responsive to the transmitted driving signal, the pointer including a signal processor responsive to the information and the amplitude of the driving signal on a selected plurality of successive conductors for generating a positional signal and causing the positional signal to be transmitted a selected time after receipt of the information and the amplitudes and further including a transmitter system coupled to the signal processor for transmitting the positional signal, and a signal detector system for detecting the transmitted positional signal.

Abstract: A high accuracy digitizer system for determining the position of a pointer relative to a tablet comprising a tablet having a positional grid thereon, a processor for determining the coarse position of the pointer relative to the tablet, and an error correction system for generating the true position of the pointer relative to the tablet. In a particular embodiment, the pointer includes an electromagnetic transducer for inducing a signal in the positional grid and the processor is coupled to the positional grid for sensing the signal and generating the coarse position of the pointer. The error correction system receives the coarse position from the processor and generates a true position, the positional grid containing positional inaccuracies therein and the error correction system correcting for such inaccuracies.

Abstract: An improved service station for a printer having a print head comprising a service station for preventing clogging of the nozzles of said print head and a bracket coupled to the service station and rotatably supporting the service station along an extended pivot for restricting movement of the service station to a first selected direction, whereby proper alignment and positioning of the service station with the print head is maintained. The print head moves along a second selected direction toward the service means and the bracket is coupled to the service station along the second selected direction to provide uniform support along the second selected direction. In a particular embodiment, the bracket is an extended hinge-type bracket and is coupled to the service station and a side wall of the printer along the length of the bracket along the second selected direction.

Abstract: An ink jet cartridge comprising an ink chamber, at least one aperture coupling a pressure relief chamber to the ink chamber, the aperture having a small internal diameter for creating a negative pressure on any ink in the lower portion of the ink chamber and a plurality of microparticles positioned in the pressure relief chamber for forming a plurality of small interstices which form a capillary path in the pressure relief chamber, the microparticles creating a negative pressure on any ink in the lower portion of the ink chamber and the selected size of the microparticles resulting in a capillary path of selected size for controlling the magnitude of the negative pressure in the lower portion of the ink chamber. The pressure relief chamber is positioned below the ink chamber, the ink chamber including an opening to couple the ink cartridge to an ink jet head and the aperture is positioned at the lower portion of the ink chamber.

Abstract: An improved ink cartridge comprising an ink chamber, a pressure relief chamber coupled to the ink chamber, and at least one air bleed hole coupling the pressure relief chamber to the ink chamber, the air bleed hole having a capillary dimension for creating a negative pressure on any ink in the air chamber. The pressure relief chamber is positioned below the ink chamber, the ink chamber including an opening to couple the ink cartridge to an ink head, the opening including an automatic shutoff valve, and the air bleed hole is positioned at the bottom of the ink chamber.

Abstract: An improved ink delivery system for an ink jet printer having a print carriage that traverses across a print medium comprising an ink source, a print head, and a coupler for coupling the ink source to the print head, the coupler including a pair of flexible tubes for carrying the ink and a Y-coupler for coupling to the pair of flexible tubes and the ink source, the Y-coupler causing the pair of flexible tubes to initially diverge. A check valve is provided to prevent back siphoning.

Abstract: A high efficiency passive pointer digitizer system comprising first and second sets of orthogonal and substantially coplanar conductors, a signal generator for generating a driving signal selectively along the first set of conductors, a movable pointer inductively coupled to the first and second sets of conductors, the pointer including a tuned circuit responsive to the driving signal for radiating a positional signal, a signal detector for detecting a positional signal induced in the second set of conductors by the tuned circuit responding to the driving signal, and a signal processor coupled to the signal generator and the signal detector for determining the location of the pointer relative to the conductors.

Abstract: The bag includes a selected volume of gas having a selected volume of dead space. The dead space being provided to accommodate expansion of the gas in the event of atmospheric and temperature changes. The dead space is within a range of 9% to 9.5% of the combined volume of the bag. The selected volume of air is sufficient such that complete drainage of an ink supply line to the printhead is allowed.

Abstract: An improved sensor system for a printer having a print carriage comprising an ink source, a print head, and a coupler for coupling the ink source to the print head, the coupler including a tube for carrying the ink and sensors for detecting voids in the ink carried by the tubes and positioned in close proximity to the ink source and the print head. A controller is coupled to the sensors and responsive to signals therefrom to stop the print carriage when voids are simultaneously detected by the sensors.

Abstract: A media position sensing system for a plotter in which a media is driven along at least one edge thereof comprising a plurality of apertures in the media positioned within the width of the edge and an optical detector positioned along the edge for sensing the appearance of the apertures in order to sense a selected position of the media. In a particular embodiment, the width of the apertures are less than one-half the width of the edge and are offset spaced from one another across the width of the edge to present an effective detection capability equivalent to a single aperture having a width equal to the width of the edge. The apertures extend along the length of the media a distance approximately equal to the width of the edge and are located near the end of the length of the media for sensing the end of the media.

Abstract: A printed wire electrostatic printing transducer having two or more rows of styli together defining the recording stylus configuration and an associated method for producing such a transducer by printed circuit techniques. Provision is made for the integration of counter electrodes and multiplexing circuitry with the transducer in a single package.

Abstract: A lubrication system for thermally-imaged films comprising a thermally-active imaging film including a thermally-active imaging layer, a lubrication layer including poly(tetra-fluoroethylene) particulates coupled to said thermally-active imaging layer, and a temperature control for controlling the temperature of the lubrication layer to prevent distortion. In a particular embodiment, the lubrication layer comprises a polymeric binder having about three percent poly(tetra-fluoroethylene) particulates therein and the imaging layer includes a polymer matrix having a heat activated image producing compound therein. The temperature control prevents a heat buildup in the lubrication layer in excess of 230 millijoules per pixel.

Abstract: In a mechanical device in which a member is moved by an electrical actuator through an electronic and mechanical linkage, apparatus for compensating for changes in system gain to allow precision movement with non-precision components. There a sensor for accurately determining positions of the member, control logic connected to provide a control signal to the actuator, and an adjustable gain control for adjusting the gain of the control signal. Compensation logic is connected to receive positional signals from the sensor, for applying a control signal to the actuator to move the member to a target position closest to a desired final position, for adjusting the gain of the control signal with the adjustable gain control until the member is located at the target position within acceptable tolerance limits, and for then employing that gain to move the member to the desired final position. The method associated with the apparatus can be done in real-time or by pre-calibrating in advance.

Abstract: Apparatus and an associated method for ascertaining the operational status of a pen in a vector plotter in which a pen is moved into contact with a paper web at a test location, the pen is moved relative to the web and an optical detector is used to determine whether or not the pen is drawing a line on the web. The web is moved from a supply roll to a take-up roll to move the test area on the web to an optical testing location. The absence of a line after a pre-determined period of web movement time signals the inoperative status of the pen and the detection of a line by the pen within that pre-determined period of movement time signals that the pen is operative. Quality and proper line width of the line can also be determined.

Abstract: Apparatus for automatically determining if roll or cut-sheet media is being used in a plotter or similar device and for automatically setting some of the operating parameters in lieu of manual input by an operator. The roll media has a hole therein adjacent the roll end. An optical sensing pair senses the passage of light through the media at a point passed by the hole. If a suspected end is found, the media is moved a distance greater than the hole diameter. If light is still detected, the edge of a cut sheet has been detected. If light is no longer detected, it was a hole and the end of a roll of media has been detected. By being able to determine the type of media involved, the plotter logic can measure the width of the media and then get a desired length from a look-up table and thereafter determine if there is a proper length of media available for the plot.

Abstract: An actuator mechanism for a pencil carriage in which a motor is coupled to a lead holder to move the lead holder relative to a drawing media surface, a pusher mechanism moves a lead carried by an internal of the lead holder relative to the position of the lead holder and the drawing media surface independently of the movement of the lead holder and a plotter control and sensors coupled thereto are provided for synchronizing the operation of the motor and the pusher mechanism to control the position of the lead relative to the lead holder and the drawing media surface. In a particular embodiment, the pusher mechanism includes a pusher rod for engaging the lead, a movable rack and a pinion gear engaged therewith, the movable rack being coupled to the pusher rod to move the lead, and a motor for driving the pinion gear.

Abstract: A combined display and electromagnetic digitizing input device for pen-driven computers. There is a graphics display panel having a viewing surface and a back surface. A first grid of parallel transparent conductors for connection to electromagnetic digitizing electronics to sense the location of an electromagnetic stylus is disposed over one of the surfaces. A second grid of parallel transparent conductors for connection to the electromagnetic digitizing electronics is disposed over the first grid of parallel transparent conductors electrically insulated therefrom and perpendicular thereto. The two grids are constructed of flexible transparent substrates carrying a plurality of transparent indium tin oxide conductors thereon. For improved performance, shielding is provided in the form of a sheet of a transparent conductive material connected to ground potential disposed below the grids of conductors as well as a sheet of a metal foil disposed across the extents of the grids of conductors.

Abstract: A media stripper mechanism for a plotter in which the media is supported by a support having a recess therein adapted to be covered by the media. A stripper is positioned external of the support and is adapted to be extended a preselected distance into the recess. A mover is provided for moving the stripper into the recess prior to the covering thereof by the media, whereby the media is stripped from the support by the stripper.

Abstract: A media cutter mechanism for a plotter in which the media is supported by a rotating support having one or more continuous recesses therein positioned to be at least partially covered by the media, the media being stationary with respect to the rotating support. One or more cutters are positioned external of the support and are movable a preselected distance into the recesses. Movers are provided for moving the cutters into the recesses to cut the media covering the recesses. In a particular embodiment, a plurality of individual cutters are employed and a plurality of commonly driven individual cams interact with the cutters for individually moving the individual cutters into the recesses. A controller is provided for controlling the individual cams to cut the media into preselected widths. In addition, a driver is provided for commonly driving the individual cutters.