摘要:
Individual printheads are joined together in a manner to provide improved alignment and registration. The multiple printhead assembly is then installed and removed from the printer as a single unit. According to a preferred method of forming the assembly, individual printheads are temporarily mounted on a holddown plate. The location and position of the printheads is monitored and a fast-cure adhesive used to monolithically join the individual printheads together as a unitary assembly. Once the adhesive is cured, the temporary securing of the individual printheads is removed and the entire assembly removed as a single unit from the holddown plate.
摘要:
A thermal ink-jet printhead adapted to emit ink onto a print sheet is automatically adjusted. The printhead is caused to emit ink onto a sheet in a manner consistent with an image of a first density, and then substantially immediately caused to emit ink in the form of a first test pattern on the sheet. The density of the first test pattern on the sheet is measured. The printhead is caused to emit ink onto the sheet in a manner consistent with an image of a second density, and then substantially immediately caused to emit ink in the form of a second test pattern on the sheet. The density of the second test pattern on the sheet is measured. The densities of the first test pattern and the second test pattern are correlated with a function relating a characteristic of an image printed with the printhead to a temperature of the printhead.
摘要:
A control system for a printer having at least one heating element for producing spots applies one of a plurality of voltage levels to at least one heating element disposed on a printhead. A voltage supply supplies a voltage to a first one of a plurality of switches connected in series with a last one of the switches being connected to the at least one heating element. At least one of the switches defines a first path and a second path having different voltage drops. A controller coupled to the plurality of switches selectively actuates the switches to apply one of a plurality of predetermined voltages to the at least one heating element.
摘要:
An apparatus and method compensates for a voltage drop of electrical pulse signals selectively applied to a plurality of heater elements on a printhead of an ink jet printing device. A number of heater elements to be pulsed at a given time is determined and a time duration of each of the pulse signals is selected based on information including the determined number of heater elements to be pulsed. In another aspect, the position on the printhead of the heater elements to be pulsed is determined and the time duration of the pulse signals is selected further based on the determined position. By varying the time duration of the pulse signals applied to the heater elements, a voltage drop across the heater elements due to the number of heater elements simultaneously pulsed and/or the position of the heater elements on the printhead is compensated for, maintaining reliable jetting performance while minimizing the voltage by which operating printing voltage needs to exceed the threshold printing voltage.
摘要:
A thermal ink-jet printhead comprises a substrate having a plurality of heating elements defined thereon. A thermistor, disposed on the substrate, includes a conductor loop which does not encompass the heating elements on the substrate. The configuration of the thermistor significantly reduces both electromagnetic and capacitance interference caused by the heating elements.
摘要:
A system controls an ink jet printing apparatus for propelling ink jet droplets on demand from a printhead having a plurality of drop ejectors. In the printhead, each ejector includes a heating element actuable in response to electrical input signals, each input signal having an amplitude and a time duration, selectably applied to the heating element to produce a temporary vapor bubble and cause a quantity of ink to be emitted for the creation of a mark on a copy sheet. The temperature of ink in the printhead is sensed, and a combination of power level and time duration of the electrical input signal for the heating element to result in a desired size of the mark of the copy sheet is selected, by entering the sensed temperature of the ink into a predetermined function relating the energy of the electrical input signal to the corresponding resulting size of the mark on the copy sheet.
摘要:
A thermal ink jet printhead is controlled to minimize missing droplets at elevated operating temperatures by varying the voltage and pulse width applied to the heater element that causes droplets to be formed and ejected. Increasing the applied voltage reduces the size of the formed droplets. At increased operating temperatures, smaller droplets minimize the introduction of air into the nozzles of the printhead upon ejection. Minimizing the introduction of air eliminates printhead misfirings and causes more consistent jetting of the ink droplets.
摘要:
An improved temperature compensation method is disclosed in which a temperature sensing thermistor is formed on a substrate whose temperature is to be series of fractional thermistors which are selectively shorted out during a manufacturing process to provide a compensation for manufacturing variabilities of the temperature coefficient of resistance of the thermistor.
摘要:
A power control system in a thermal ink-jet printer facilitates practically instantaneous voltage changes to a heating element. A first set of selectably-actuable voltage lines is operatively connected in parallel to a first terminal of the heating element, each line having associated therewith a predetermined voltage output. A second set of selectably-actuable voltage lines is operatively connected in parallel to a second terminal of the heating element, each line having associated therewith a predetermined voltage output. One of the first set of selectably-actuable voltage lines and one of the second set of selectably-actuable voltage lines are activated as required.
摘要:
Data relating to the performance of an individual ink-jet printhead is stored in an electrically-readable form on a silicon substrate forming an essential part of the printhead. A template of electrically-detectable structure is created on the substrate at manufacture, and then portions of the structure are removed in accordance with the data desired to be stored. In one embodiment, the digital performance data may be encoded and also read out in serial form using a shift register on the chip.