Abstract: An n-bit serial shift register in an ink jet print head operates in a print mode or a test mode. When the shift register is operating in the print mode, n bits of print data are serially scanned into n number of bit registers and are then latched out to heater addressing logic circuitry in the print head to control a print operation. When the circuit is operating in the test mode, x bits of test point data from x number of test nodes in the print head are loaded in parallel into x number of the n number of bit registers, and are then serially scanned out to a test data output. In this manner, a single shift register may be used to scan in print data and scan out test data, thereby providing observability and controllability of the internal logic nodes of the print head while minimizing logic size and the number of input/output connections on the print head.

Abstract: A system is described for compensating for misalignments in an ink jet printer having an ink jet print head cartridge that includes a heater chip. The system includes determining alignment adjustment information related to the misalignments in the ink jet printer, loading the alignment adjustment information into a volatile memory device on the heater chip, and accessing the alignment adjustment information from the volatile memory device. The system also includes generating nozzle control signals based at least in part on the alignment adjustment information. The nozzle control signals are selectively provided to resistive heating elements in the heater chip, thereby heating ink in ink chambers adjacent the heating elements and ejecting ink droplets toward a print medium. The timing of the nozzle control signals is adjusted based upon the amount of misalignment in the various components of the printer and print head.

Abstract: A system is described for compensating for misalignments in an ink jet printer having an ink jet print head cartridge that includes a heater chip. The system includes determining alignment adjustment information related to the misalignments in the ink jet printer, loading the alignment adjustment information into a volatile memory device on the heater chip, and accessing the alignment adjustment information from the volatile memory device. The system also includes generating nozzle control signals based at least in part on the alignment adjustment information. The nozzle control signals are selectively provided to resistive heating elements in the heater chip, thereby heating ink in ink chambers adjacent the heating elements and ejecting ink droplets toward a print medium. The timing of the nozzle control signals is adjusted based upon the amount of misalignment in the various components of the printer and print head.