Abstract: A method of preventing printing artifacts by detecting a distance between the print head and the recording medium as the print head and the recording medium and utilizes the detected distance in determining an adjusted ink ejection frequency. The adjusted ejection frequency for each print head scan position may be stored in a look up table.

Abstract: A printing apparatus of the present invention includes a print head having a plurality of nozzles, from which ink droplets are ejected, a light detection unit that has a light emitting element and a light receiving element and determines the active or inactive state of the nozzles based on whether or not the light beam is intercepted by ink droplets, and a carriage that moves the print head relative to the light detection unit. The light beam emitted from the light emitting element has an optical axis that is inclined at a predetermined angle to a nozzle array. At least part of the plurality of nozzles are inspected while the print head is moving relative to the light detection unit at a fixed speed.

Abstract: Techniques to compensate for random and systematic errors when measuring dot placement errors. Error accumulation due to scan axis irregularities during printhead calibration is minimized by swapping alignment block positions on the print medium from swath to swath. Print media advances during the calibration are minimized by the use of a moving reference instead of a constant reference; adjacent groups of nozzles are used to calibrate the following group. Only a small media advance is needed to print alignment blocks using adjacent nozzle groups one beside the other to be calibrated. To prevent paper slip accumulative errors when using moving references, the order of the groups of nozzles is swapped from one paper advance to the other. This randomizes for small, unavoidable slips when advancing the paper and prevents error accumulation.

Abstract: A drive method and a drive of an ink-jet recording head which is capable of improving recording speed widely, and which is capable of materializing high quality recording without extending recording time even though the number of gradations increase, are provided. One-printing period T is divided into a plurality of segment T1, T2. The method and device cause plural kinds of drive-voltage-waveform SD1 to SD6 to be generated in accordance with size of an ink-drop in every respective segment T1, T2. The method and device select arbitrary drive-voltage-waveforms from among the plural kinds of drive-voltage-waveforms SD1 to SD6 supplied in every respective segment T1, T2 to supply to a vibration generator in every respective segment T1, T2. Thus it becomes possible to obtain a plurality of gradations during one-printing period T. It is capable of obtaining high quality printing image while improving recording speed widely. Further, printing time is not extended even though the number of gradations increase.

Abstract: An ink jet print cartridge is provided for use in an ink jet printer. The cartridge comprises a printhead including a heater chip. The printhead is adapted to generate ink droplets in response to the heater chip receiving energy pulses from a printer energy supply circuit. A peltier effect cooling cell is associated with the heater chip for cooling the heater chip. The cooling cell receives current from the printer energy supply circuit as a function of energy flow to the heater chip.