Abstract: A system and method for testing printheads is disclosed. The system comprises an optical sensor mounted on a movable carriage. The optical sensor is moved past a nozzle to be tested on the printhead while the nozzle ejects ink. The output signal of the optical sensor can be used to determine when the trajectory of the ejected ink is improper.

Abstract: Printhead control systems and methods for controlling a printhead A printhead control system comprises a voltage supply control module to selectively supply an operating voltage to a printhead, and the voltage supply control module is configured to receive a first and a second control voltages, and to disconnect the supply of operating voltage to the printhead at least when the first and second control voltages have the same logical level.

Abstract: A shield for an electrical connector comprises a conductive housing configured to enclose an exposed portion of at least one electrical connector. The shield further comprises at least one opening formed in the conductive housing configured to allow a corresponding mating portion of each of the at least one electrical connectors to be exposed. The shield further comprises and a plurality of conductive points located along at least one circumferential path within the conductive housing remote from the at least one opening.

Abstract: A method and apparatus for controlling firing energy in a printer pen of a thermal inkjet printer are described. A digital voltage value representative of a voltage output by a printer-pen power supply is obtained. The printer-pen power supply is electrically coupled to a switch. The switch is electrically coupled to a nozzle resistor and is controlled using a switch logic signal. A voltage level of the switch logic signal is set based on said digital voltage value and a voltage drop due to a parasitic resistance between the printer-pen power supply and the switch.

Abstract: A method and apparatus for controlling firing energy in a printer pen of a thermal inkjet printer are described. A digital voltage value representative of a voltage output by a printer-pen power supply is obtained. The printer-pen power supply is electrically coupled to a switch. The switch is electrically coupled to a nozzle resistor and is controlled using a switch logic signal. A voltage level of the switch logic signal is set based on said digital voltage value and a voltage drop due to a parasitic resistance between the printer-pen power supply and the switch.

Abstract: An apparatus and methods for measuring a current flowing into an electrical device are described. In the apparatus, a current sensing circuit has at least one monolithic device, which in turn has a positive operating voltage and a negative operating voltage. The current sensing circuit is coupled to a power supply for the electrical device and the at least one monolithic device is arranged to enable a signal representative of the input current from the power supply to the electrical device to be output. The apparatus also has a power converter for converting a first voltage output by the power supply to a second voltage for supply as the positive operating voltage and a voltage clamp arranged to clamp the difference between the positive and negative operating voltages.

Abstract: A shield for an electrical connector comprises a conductive housing configured to enclose an exposed portion of at least one electrical connector. The shield further comprises at least one opening formed in the conductive housing configured to allow a corresponding mating portion of each of the at least one electrical connectors to be exposed. The shield further comprises and a plurality of conductive points located along at least one circumferential path within the conductive housing remote from the at least one opening.

Abstract: A printed circuit board comprises at least one microstrip transmission line with a conductive solid reference plane and at least one conductive trace embedded in a dielectric substrate, and further comprises at least one conductive shielding layer having a lattice structure, wherein the conductive trace is arranged between the solid reference plane and the shielding layer.

Abstract: A signal separation module includes a single-ended bidirectional pin coupled to a processing device, a single-ended unidirectional output pin coupled to a differential signal transceiver, a single-ended unidirectional input pin coupled to the differential signal transceiver, and signal separation logic. The signal separation logic is to detect a current flow condition that indicates the bidirectional pin is asserted by the processing device; assert, as a result of the existence of the current flow condition, the unidirectional output pin and prevent the unidirectional input pin from affecting the bidirectional pin; detect an opposite current flow condition that indicates that the unidirectional input pin is asserted by the differential signal transceiver; and assert, as a result of the existence of the opposite current flow condition, the bidirectional pin and prevent the assertion of the bidirectional pin from affecting the unidirectional output pin.

Abstract: Printhead firing methods, apparatus and articles of manufacture are disclosed. An example printhead firing method disclosed herein comprises determining a position of a printer carriage corresponding to a location at which a first encoder strip is concatenated with a second encoder strip, and adjusting timing of printhead firing pulses when the printer carriage is determined to have reached the position as the printer carriage is moved.

Abstract: An electronic device has a transmitter, a microprocessor in communication with the transmitter, a receiver that communicates with the transmitter along a cable using differential signaling, and a transistor. The transistor switches states to communicate a signal to the microprocessor when a wire in the cable is faulty.

Abstract: Printhead firing methods, apparatus and articles of manufacture are disclosed. An example printhead firing method disclosed herein comprises determining a position of a printer carriage corresponding to a location at which a first encoder strip is concatenated with a second encoder strip, and adjusting timing of printhead firing pulses when the printer carriage is determined to have reached the position as the printer carriage is moved.