Abstract: A method of operating a thermal inkjet printer having a thermal inkjet printhead that includes the steps of selecting an ink drop volume, selecting a pulse width that will cause the thermal inkjet printhead to deposit an ink drop having the selected drop volume, and operating the thermal inkjet printhead with the selected pulse width and at an operating energy that is greater than a turn-on energy of the printhead for the selected pulse width.

Abstract: An inkjet printer system fires smaller ink droplets in a single-pass print mode to achieve addressible print resolution of 600 dpi in the carriage scan axis along with 300 dpi resolution in the media advance axis, without having to employ any dot-depletion algorithms. In one embodiment, the system provides a fast print mode which prints the smaller drops of ink on a 300 dpi grid in the carriage scan axis. In another embodiment, the system provides a single-pass color print mode wherein primary colors are printed with two color droplets of the same primary color in two adjacent sub-pixels on the 300.times.600 grid, and secondary colors are printed with two color droplets of different primary colors in two adjacent sub-pixels on the 300.times.600 grid.

Abstract: An inkjet printer system fires smaller ink droplets in a single-pass print mode to achieve addressible print resolution of 600 dpi in the carriage scan axis along with 300 dpi resolution in the media advance axis, without having to employ any dot-depletion algorithms. In one embodiment, the system provides a fast print mode which prints the smaller drops of ink on a 300 dpi grid in the carriage scan axis. In another embodiment, the system provides a single-pass color print mode wherein primary colors are printed with two color droplets of the same primary color in two adjacent sub-pixels on the 300.times.600 grid, and secondary colors are printed with two color droplets of different primary colors in two adjacent sub-pixels on the 300.times.600 grid.

Abstract: An inkjet printer has a pen holder for removably holding an ink pen, a detector circuit for detecting whether ink with a degraded quality is likely to be ejected by said ink pen, and a servicing circuit responsive to said detector circuit for causing an initial quantity of ink to be discharged from said ink pen to ensure that ink with a degraded quality will not be used during normal printing.

Abstract: A method for operating a thermal ink jet printer including a printhead having ink firing heater resistors responsive to pulses provided to the printhead. Warming voltage pulses are applied to the printhead to warm the printhead to a temperature that is at least as high as a temperature that would be produced pursuant to ink firing pulses of a predetermined voltage, a predetermined pulse width, and a predetermined pulse frequency. A continuous series of ink firing pulses are then applied to the printhead, starting with a pulse energy substantially equal to the predetermined reference pulse energy and a pulse frequency equal to the predetermined pulse frequency, and then incrementally decreasing the pulse energy of the ink firing pulses. The temperature of the printhead is repeatedly sampled while the ink firing pulses are applied to the ink firing resistors to produce a set of temperature samples respectively associated with the decreasing pulse energies.

Abstract: A thermal ink jet printhead including a thin film substrate with a plurality of polygon shaped thin film resistors, a barrier layer overlying the substrate, and respective firing chambers formed in the barrier layer for each of the resistors. Each firing chamber is formed of a continuously curved concave wall having ends adjacent the boundary of the resistor, and which is within the boundary of the area defined by the resistor and a 10 micrometer wide margin around the resistor.

Abstract: A method for operating a thermal ink jet printer including a printhead having ink firing heater resistors responsive to pulses provided to the printhead. Warming voltage pulses are applied to the printhead to warm the printhead to a temperature that is at least as high as a temperature that would be produced pursuant to ink firing pulses of a predetermined voltage, a predetermined pulse width, and a predetermined pulse frequency. A continuous series of ink firing pulses are then applied to the printhead, starting with a pulse energy substantially equal to the predetermined reference pulse energy and a pulse frequency equal to the predetermined pulse frequency, and then incrementally decreasing the pulse energy of the ink firing pulses. The temperature of the printhead is repeatedly sampled while the ink firing pulses are applied to the ink firing resistors to produce a set of temperature samples respectively associated with the decreasing pulse energies.

Abstract: A paper moving system for a computer driven printer/plotter comprises a paper pinching assembly positioned at the two oppositely facing edges of the paper adjacent the print zone 10. The edges of the paper are fed through each assembly where the paper is gripped between a lubricous shim plate 52 and a straight stretch of a paper drive belt 42 which frictionally engages the paper. The belts of each assembly are biased toward the shim plates by a spring urged rail 50 to hold the belts in non-slip engagement with the paper. The paper is tensioned edge to edge by the assemblies so that a paper table or platen underneath the print zone is unnecessary.