摘要:
A printhead uses large and small drop ejectors to achieve efficient gray scale printing. The printhead is arranged with a close packed configuration of alternating large and small nozzles positioned to maximize coverage while minimizing the volume of ejected ink. The printhead may be operated in a single pass mode or dual pass mode. In the single pass mode, complete coverage is effected by rippling through the odd numbered jets first and then rippling through the even numbered jets. The position of the small spots from the even numbered jets can be adjusted to maximize coverage and counteract offset between nozzle centers. Printheads with different size nozzles can also be operated by a staggered firing method using dual passes to offset spots in the scan direction by shifting the printhead between passes or alternating between groups of large and small nozzles. Further improvements to image quality can be realized by shifting the spots in the direction perpendicular to the scanning direction by tilting the printhead or offsetting the nozzles with respect to the ink channels on the printhead.
摘要:
The new heater element design has a pit layer which protects the overglaze passivation layer, PSG step region, portions of the Ta layer and dielectric isolation layer and junctions or regions susceptible to the cavitational pressures. Further, the inner walls of the pit layer define the effective heater area and the dopant lines define the actual heater area. In alternative embodiments, the dopant lines define the actual and effective heater areas, and an inner wall and a dopant line define the actual and effective heater areas. Further, when the new heater element designs are incorporated into printheads having full pit channel geometry and open pit channel geometry, the operating lifetime of the printhead is extended because the added protection of the pit layer prevents: 1) passivation damage and cavitational damages of the heater elements; and 2) degradation of heater robustness, hot spot formations and heater failures well into the 109 pulse range. The printhead incorporating the new heater element design can be incorporated into drop-on-demand printing systems of a carriage type or a full width type.
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:
An ink-jet printer includes a printhead disposed on a reciprocating carriage. The printhead includes two sets of ejectors spaced by a predetermined pitch, in collinear linear arrays. The two sets of ejectors are offset by a partial pitch to enable interleaving of print swaths by the two sets of ejectors, in order to print at a higher resolution than the predetermined pitch would allow.
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:
Relatively small fluid handling devices having a filter bonded on the surface containing the fluid inlets. An example of such a device is a thermal ink jet printhead. A substantially flat filter is placed at the ink inlet to the printhead by a fabrication process which laminates a wafer sized filter to the aligned and bonded wafers containing a plurality of printheads. The individual printheads are obtained by a sectioning operation, which cuts through the two or more bonded wafers and the filter. The filter may be a woven mesh screen or, preferably, an electroformed screen with a predetermined pore size. Since the filter covers one entire side of the printhead, the relatively large contact area prevents delamination and enables convenient leak-free sealing. The filter prevents the entrance of contaminants into the relatively large inlets of the printhead at an early stage of assembly and packaging.
摘要:
An inkjet printhead having a drop ejector array, an ink passageway for providing ink to the drop ejector array, and a thermally actuated degassing unit. The degassing unit itself includes a body enclosing an air chamber, a check valve configured to allow air to vent from the air chamber to ambient when the pressure in the air chamber exceeds ambient air pressure by a predetermined amount. The thermal degassing unit includes a thermally-induced pressure build-up time to increase the pressure in the air chamber. The air chamber is allowed to cool which causes internal pressure to drop below ambient and draws gas out of the ink.
摘要:
A stationary printing apparatus includes a display; a camera to capture an image, the camera being mounted proximate the display; and a printing mechanism configured to print the image.
摘要:
A method of controlling in a printer the maintenance of an inkjet printhead supplied with fluid from a plurality of fluid sources, the method includes the steps of (a) monitoring the usage of the plurality of fluid sources; (b) identifying a preferred fluid source for use in a maintenance operation based on the monitored usage of the plurality of fluid sources; and (c) performing the maintenance operation using a first quantity of fluid from the preferred fluid source.
摘要:
A method of operating a scanning apparatus including a transparent platen, a memory, a lid to cover the transparent platen, and a door in the lid, the method includes exposing a portion of the transparent platen through the door in the lid; placing a user identifier into the door in the lid; providing a user identification initiation signal; emitting light from a light source to illuminate the exposed portion of the transparent platen; moving a photosensor array to scan the user identifier through the exposed portion of the transparent platen; providing a digitized image of the user identifier from the scan by the photosensor array; comparing the digitized image to a stored pattern; and authorizing a function of the scanning apparatus if it is determined that the digitized image of the user identifier adequately matches the stored pattern.