| Patent application number | Description | Published |
|---|
| 20090015184 | System for measuring current in multiple motor coils using a single sensing element - A circuit enables current to be measured in at least two motor leads of a three-phase motor being supplied by a power source generating a chopped sinusoidal waveform for the motor leads. The circuit includes a DC power supply having a pair of output terminals, a current sense transformer having a primary winding and a secondary winding, the primary winding being connected at one end to one output terminal of the DC power supply, an H-bridge driver connected to another end of the primary winding and being connected to leads of a three-phase motor to drive each lead to a voltage obtained from the DC power supply through the primary winding, a regulating circuit for identifying the voltage to which each lead is to be driven and for controlling switches within the H-bridge circuit to drive each lead to an identified voltage, and a single current sense resistor connected to the secondary winding of the current sense transformer, the current sense resistor generating a voltage that corresponds to the current being used to drive the three-phase motor. | 01-15-2009 |
| 20090128591 | System and method for measuring a supply of solid ink in a solid ink printer - A solid ink printer includes a solid ink measurement system that helps ensure an adequate supply of solid ink is in the feed channels delivering solid ink to a melting device within a printer. The solid ink measurement system includes a driving electrode mounted along a substantial length of a first structure of a first solid ink feed channel, a sensing electrode mounted along a substantial length of a second structure of the first solid ink feed channel, the sensing electrode being opposite and generally parallel to the driving electrode, an AC voltage source coupled to the driving electrode to generate an electrical field emitted from the driving electrode, and a capacitance measurement circuit coupled to the sensing electrode to receive an electrical signal induced in the sensing electrode by the electrical field generated by the driving electrode, the capacitance measurement circuit being configured to identify an amount of solid ink in the first feed channel that corresponds to the electrical signal received from the sensing electrode. | 05-21-2009 |
| 20090279912 | TRANSFIX ROLLER LOAD CONTROLLED BY FORCE FEEDBACK - A printing device has an image receptor adapted to have an image formed thereon. The printing device also includes a transfer roller and a motor. A transfer roller load mechanism moves the transfer roller into contact with the image receptor in response to the motor output. A controller manipulates the motor in conjunction with a feedback signal from a load detector and regulates the load of the transfer roller. | 11-12-2009 |
| 20090285591 | TRANSFIX FOLLER LOAD CONTROLLED BY FORCE FEEDBACK - A printing device has an image receptor adapted to have an image formed thereon. The printing device also includes a transfer roller and a motor. A transfer roller load mechanism moves the transfer roller into contact with the image receptor in response to the motor output. A controller manipulates the motor in conjunction with a feedback signal from a load detector and regulates the load of the transfer roller. | 11-19-2009 |
| 20090321520 | ENCODER HOME POSITION SENSING METHOD AND SYSTEM - An encoder home position sensing system and method is disclosed, which includes the use of an analog quadrature encoder reader and either a code wheel or a code strip. The code wheel possesses an optical track comprised of annular ring patterns, the thickness of which can be modulated by a sinusoidal function about the code wheel circumference, with one cycle of a sine wave corresponding to one encoder cycle. In one region of the optical track the amplitude of the sine function is changed to imbed an absolute reference home position. This region of the optical track can be sensed and used to determine an absolute system position. The linear code strip is similarly constructed with lines along the direction of motion, the thickness of which are modulated with a sine function, with one cycle of the sine wave corresponding to one encoder cycle, and the amplitude of the sine wave function changed to imbed an absolute reference home position in the optical track. | 12-31-2009 |
| 20090322807 | FLUID LEVEL SENSING SYSTEM AND METHOD - An ink level sensing system that exhibits good sensitivity is described herein. The system includes a first probe having a first active surface, a second probe having a second active surface facing the first active surface, a memory in which data indicative of a conductivity curve and command instructions are stored, and a processor configured to execute the command instructions to associate a level of fluid in a reservoir with a first signal indicative of the electrical coupling between the first active surface and the second active surface with reference to the data indicative of a conductivity curve. | 12-31-2009 |
| 20100007691 | Ink Consumption Determination - An ink jet printer includes an ink feed apparatus. The ink feed apparatus includes an ink feed channel for conducting discrete substantially solid ink sticks along a feed channel path, a plurality of ink sticks in the ink feed channel, each of the ink sticks comprising an ink stick body having an ink stick sensing feature on an external surface of the ink stick body that is located between a first end and a second end of the ink stick body, and each of the ink stick bodies has substantially the same mass as the other ink stick bodies in the plurality, a detector positioned at a fixed position proximate the ink feed channel and configured to be triggered by an ink stick sensing feature on an ink stick in the ink feed channel as the ink stick moves along the ink feed path past the detector, and a counter configured to accumulate the number of times the detector is triggered. | 01-14-2010 |
| 20100060677 | Drive Belt Slip and Belt Wear Detection - An imaging system for a printer utilizing a friction belt drum drive is comprised of a drum position sensor, drum pulley, drive belt, motor pulley, drive motor, drive motor position sensor, and controller. The velocities of the drum and motor drive pulleys are measured using the controller and position sensors. These velocities along with the drive ratio are used to determine and monitor slip between the belt and pulleys. The magnitude of the slip measured can be used to trigger the controller to respond to the slip event. These responses may include, for example, disabling the motor or reducing motor current or providing a warning indicative of an excessive slip event. Slip measurement combined with other measurements such as motor current can be used to determine the torque capacity of the friction drive. Further, long-term changes in the ratio of pulley velocities can be used to determine drive belt wear. | 03-11-2010 |
| 20100077854 | Circuit Design to Prevent False Level Sense Readings - A circuit for conveying signals between one or more ink level sensors and a circuit includes a substrate having a circuit end, a sensor end, and an elongated body extending therebetween. The sensor end includes a bottom layer in which the first signal trace is routed and a top layer in which the second and third signal traces are routed. The sensor end includes a first, a second, and a third connector each extending through the top and the bottom layers that are electrically connected to a first signal trace, a second signal trace, and a third signal trace, respectively, in the substrate. The first connector, the second connector, and the third connector are configured for electrical connection to a first probe, a second probe, and a third probe, respectively, of the level sensor. A first ground trace is positioned in the sensor end that includes a first continuous guard ring in the top layer completely surrounding and spaced from the first connector, and a first segmented guard ring in the bottom layer including a plurality of segments that are each electrically connected to the first continuous guard ring and being spaced from the other segments in the first segmented guard ring. The first signal trace is routed in the bottom layer to the first connector via a space between the segments of the first segmented guard ring. | 04-01-2010 |
| 20100079512 | Ink Conductivity Fault Tolerant Mode - A method of operating an imaging device comprises measuring an ink conductivity of an ink volume in an ink reservoir of an imaging device. The imaging device is operated in a conductivity fault tolerant mode in response to the measured ink conductivity being outside of a predetermined ink conductivity operational range. In the conductive fault tolerant mode, at least one parameter of a melt duty cycle for the ink reservoir is set to a corresponding conductivity fault tolerant (CFT) level. | 04-01-2010 |
| 20100188456 | System And Method For Protecting A Printer From An Over-Temperature Condition In A Printhead - A method responds to an over-temperature condition in a printhead. The method includes generating a first electrical signal corresponding to a temperature in a printhead, monitoring the first electrical signal with a first electronic circuit to terminate delivery of electrical power to a printhead in response to detection of a safety event, and monitoring the first electrical signal with a second electronic circuit to regulate an amount of electrical power delivered to the printhead. | 07-29-2010 |
| 20100192685 | Apparatus And Method For Detecting Ink In A Reservoir - A method detects the level of ink in a printhead reservoir by monitoring the power drawn by a thermistor positioned within the printhead reservoir. The method includes dissipating power in a thermistor in an ink reservoir, controlling the power dissipated in the thermistor to maintain the thermistor at a temperature that is a fixed differential above a reservoir temperature, measuring a parameter that corresponds to the power dissipated in the thermistor, and comparing the measured parameter to a predetermined value to detect ink in the reservoir contacting the thermistor. | 08-05-2010 |
| 20100277557 | Segmented Ink Stick - A method facilitates insertion of a segmented ink stick into an ink feed system of a phase change ink jet printer. The method includes bending of a flexible strand between ink stick segments during insertion of the ink stick segments and then straightening the flexible strand to orient the ink stick segments in the ink feed system. | 11-04-2010 |
| 20110102487 | Capacitive Drop Mass Measurement System - An imaging device includes an image receiving surface movably supported within the imaging device and at least one printhead having a plurality of ink jets, each ink jet being configured to eject drops of ink on the image receiving surface. At least one sensing electrode is positioned adjacent the image receiving surface that outputs capacitance signals indicative of a capacitance in a gap between the at least one sensing electrode and image receiving surface that are output to a controller. The imaging device includes a drop mass detection mode of operation in which: at least one ink jet in the plurality of ink jets is actuated to eject drops of ink to form at least one test band on the image receiving surface; the image receiving surface is moved so that the at least one test band of ink is positioned in the gap; the at least one sensing electrode outputs a test band capacitance signal indicative of a capacitance with the at least one test band in the gap; and the controller modifies an operating parameter of the imaging device based on the capacitance indicated by the test band capacitance signal. | 05-05-2011 |
