Abstract: A 3-T buried-gated photodiode device that is suitable for use in a windowed array. The 3-T buried-gated photodiode device is configured such that the floating diffusion (FD) node of the device is held low when the device is not being specifically addressed, which ensures that the device cannot drive the corresponding pixel output line unless it is specifically addressed.

Abstract: An apparatus and method for detecting a failed reset in a pixel are described. First, a reset proxy signal that is received. Second, a reset reference signal is received. The reset proxy signal and the reset reference signal are compared. Based on the comparison, a reset status signal is generated. The reset status signal indicates that a failed reset has been detected or that a failed reset has not been detected.

Abstract: Compact CMOS pixel sensors containing three or four total transistors and four or five control lines provide a high percentage of sensor area for the photodiode that measures light intensity. The CMOS pixel sensors thus have good light sensitivity. The CMOS pixel sensors also provide active reset operations yielding low noise when resetting node voltages. The low transistor count is achieved using the same transistors during both reset operations and readout operation. Reversing the current direction through a pixel sensor during readout allows the row selection transistor to act as a buffer for a transistor having a gate coupled to the photodiode node.

Abstract: An inkjet printhead assembly includes at least one inkjet printhead having nozzles and firing resisters. The inkjet printhead assembly includes fire pulse generator circuitry responsive to a start fire signal to generate fire signals, each having a series of fire pulses. The fire pulse generator circuitry generates the fire signals by controlling the initiation and duration of the fire pulses. The fire pulses control timing and activation of electrical current through the firing resisters to thereby control ejection of ink drops from the nozzles. One embodiment of the inkjet printhead assembly includes multiple printheads disposed on a carrier to form a wide-array inkjet printhead assembly.

Abstract: A printhead is provided with a data receiver and a data driver, each of which is coupled to a common data pad. The printhead is also provided with a clock pad and a data bus. Means for shifting data between the data receiver and the data driver shifts data in accordance with strobe signals received over the clock pad. Additional means transfers data from the shifting means to the data bus, and yet further means transfers data from the data bus to the shifting means.

Abstract: A printhead assembly includes at least one printhead—having an internal power supply path, a power regulator providing an offset voltage from the internal power supply path voltage, and multiple primitives. Each primitive includes a group of nozzles, a corresponding group of firing resistors, and a corresponding group of switches. The switches are controllable to couple a selected firing resistor between the internal power supply path and the offset voltage to thereby permit electrical current to pass through the selected firing resistor to cause a corresponding selected nozzle to fire.

Abstract: Compact CMOS pixel sensors containing three or four total transistors and four or five control lines provide a high percentage of sensor area for the photodiode that measures light intensity. The CMOS pixel sensors thus have good light sensitivity. The CMOS pixel sensors also provide active reset operations yielding low noise when resetting node voltages. The low transistor count is achieved using the same transistors during both reset operations and readout operation. Reversing the current direction through a pixel sensor during readout allows the row selection transistor to act as a buffer for a transistor having a gate coupled to the photodiode node.

Abstract: An inkjet printhead assembly includes at least one inkjet printhead having nozzles and firing resisters. The inkjet printhead assembly includes fire pulse generator circuitry responsive to a start fire signal to generate fire signals, each having a series of fire pulses. The fire pulse generator circuitry generates the fire signals by controlling the initiation and duration of the fire pulses. The fire pulses control timing and activation of electrical current through the firing resisters to thereby control ejection of ink drops from the nozzles. One embodiment of the inkjet printhead assembly includes multiple printheads disposed on a carrier to form a wide-array inkjet printhead assembly.

Abstract: A printhead assembly includes at least one printhead having an internal power supply path, a power regulator providing an offset voltage from the internal power supply path voltage, and multiple primitives. Each primitive includes a group of nozzles, a corresponding group of firing resisters, and a corresponding group of switches. The switches are controllable to couple a selected firing resister between the internal power supply path and the offset voltage to thereby permit electrical current to pass through the selected firing resister to cause a corresponding selected nozzle to fire.

Abstract: An apparatus and method for controlling temperature fluctuations between printhead dies in a multiple printhead die printer. By reducing temperature variations, changes in image intensity that are attributable to temperature variations are reduced.

Abstract: A voltage stabilization circuit includes a band gap reference circuit to generate a stable output voltage that is temperature-independent, and a folded cascode feedback circuit to generate a feedback potential that is applied to stabilize the band gap reference circuit. The folded cascode feedback circuit is implemented with current mirror circuits.

Abstract: A printer has a print head with multiple nozzles and firing elements for corresponding nozzles. The print head receives one or more power supply inputs to operate the firing elements. The print head has power supply fault protection circuitry to guard against harmful and destructive effects on firing resistors resulting from power supply fluctuations. The power supply fault protection circuitry is integrated into a pen-based chip that also forms the firing elements and optionally the firing logic.

Abstract: A voltage stabilization circuit includes a band gap reference circuit to generate a stable output voltage that is temperature-independent, and a folded cascode feedback circuit to generate a feedback potential that is applied to stabilize the band gap reference circuit. The folded cascode feedback circuit is implemented with current mirror circuits.

Abstract: A printer has a print head with multiple nozzles and firing elements for corresponding nozzles. The print head receives one or more power supply inputs to operate the firing elements. The print head has power supply fault protection circuitry to guard against harmful and destructive effects on firing resistors resulting from power supply fluctuations. The power supply fault protection circuitry is integrated into a pen-based chip that also forms the firing elements and optionally the firing logic.

Abstract: An inkjet printhead assembly includes at least one inkjet printhead having a group of nozzles, a group of firing resisters corresponding to the group of nozzles, a programmable nozzle firing order controller configured to provide address generator control signals, and a nozzle address generator configured to respond to the address generator control signals to provide a nozzle address. The nozzle address controls a sequence of which firing resister has electrical current pass through it at a given time to thereby control a firing order of the nozzles.

Abstract: A printhead assembly includes at least one printhead having a group of nozzles, a group of firing resisters corresponding to the group of nozzles, a programmable nozzle firing order controller configured to provide address generator control signals, and a nozzle address generator configured to respond to the address generator control signals to provide a nozzle address. The nozzle address controls a sequence of which firing resister has electrical current pass through it at a given time to thereby control a firing order of the nozzles.

Abstract: An inkjet printhead assembly includes at least one inkjet printhead having an internal power supply path, a power regulator providing an offset voltage from the internal power supply path voltage, and multiple primitives. Each primitive includes a group of nozzles, a corresponding group of firing resisters, and a corresponding group of switches. The switches are controllable to couple a selected firing resister between the internal power supply path and the offset voltage to thereby permit electrical current to pass through the selected firing resister to cause a corresponding selected nozzle to fire.

Abstract: An apparatus and method for detecting ink leakage in a print head. Conductive material is provided on a print head substrate that functions as a detector for ink that has leaked out of the established ink well or conduit. The detector conductive material is preferably arranged in proximity to power and/or control signal conductors and senses when leaked ink is threatening these conductors.

Abstract: An inkjet printhead assembly includes at least one inkjet printhead having nozzles and firing resisters. The inkjet printhead assembly includes fire pulse generator circuitry responsive to a start fire signal to generate fire signals, each having a series of fire pulses. The fire pulse generator circuitry generates the fire signals by controlling the initiation and duration of the fire pulses. The fire pulses control timing and activation of electrical current through the firing resisters to thereby control ejection of ink drops from the nozzles. One embodiment of the inkjet printhead assembly includes multiple printheads disposed on a carrier to form a wide-array inkjet printhead assembly.

Abstract: An apparatus and method for controlling temperature fluctuations between printhead dies in a multiple printhead die printer. By reducing temperature variations, changes in image intensity that are attributable to temperature variations are reduced.