摘要:
An apparatus and method to deskew sheets (100) in a short paper path in an electrophotographic printing machine by differentially driving two sets of rolls so as to create a paper buckle buffer zone (102) in the sheet (100) and then differentially driving a roll set (24,25,26,27) to correct the skew while the sheet (100) is still within the nips of multiple drive roll sets (24,25,26,27,34,35,36,37). Contrary to stalled roll techniques, leading edge damage to sheets is eliminated as the deskewing rolls are initially traveling at the same velocity as the sheet. Plural leading edge detectors (96,97) are used to measure the skew.
摘要:
A dynamic edge guide (100, 125) for use in a sheet side-edge registration system may include a moving belt (101) having raised ridges (103, 104) thereon that form a channel into which the side-edge of a sheet to be registered is inserted sheets moved through the registration system by a transport device are side registered against the belt by a scuffer mechanism (81,82), with the transport device and belt moving at substantially the same speed. In this manner, any force tending to show a sheet being registered has nothing added to it by the contact between the sheet and the edge guide. The belt (101) may be replaced by a series of rotary contact rolls (125).
摘要:
In a digital copier in which the copies are made with a reciprocating inkjet printhead, the original image to be copied is pre-scanned at high speed and low resolution, to identify an area in the original image having white space. If the white-space area in the original image is sufficiently large, the action of the printhead can be adapted to skip the corresponding area in the copy sheet in the printing process, thus increasing the overall throughput of the digital copier. An analogous technique can be used to identify non-halftone or non-color portions of an original image, which can be printed with fewer than a maximum number of passes of the printhead over a specific area of the copy sheet.
摘要:
A bi-directional fluid ejector (200) operates on the principle of electrostatic attraction. The fluid ejector includes a sealed dual diaphragm arrangement (210), an electrode arrangement (220,222) that is parallel and opposite to the sealed diaphragms, and a structure (240) which contains the fluid to be ejected. A diaphragm chamber (216,218) containing a relatively incompressible fluid is situated behind, and is sealed by, the diaphragms (210). At least one nozzle hole (242,244) is formed in a faceplate of the ejector over one of the diaphragms (210). A drive signal is applied to at least one electrode (220,222) of the electrode arrangement to generate an electrostatic field between the electrode (220,222) and a first one of the diaphragms (210). The first diaphragm is attracted towards the electrode (222) by an electrostatic force into a deformed shape due to the electrostatic field. Upon deforming, pressure is transmitted to a second one of the sealed diaphragms (210). The transmitted pressure and the relatively incompressible nature of the fluid contained within the sealed diaphragm chamber (218) causes the second diaphragm (210) to deflect in the opposite direction to force fluid through at least one of the at least one nozzle hole (242). After a drop is ejected, the movement is reversed, either through normal resilient restoration actions of the deformed diaphragm (210) and/or through an applied force generated by the other electrode (220).
摘要:
A variable sheet sized sheet feeder adapted to be reloaded while running in a dual tray mode. A dual tray sheet feeder having a sheet transport (121) to reload a stack of sheets from a holding station (104) to an active feed station (102) is provided. The dual tray design allows the holding station to be reloaded while the active tray is feeding thereby providing load while run capability. The feed tray is further provided with tray extensions (103) to allow the loading and feeding of oversized sheets within the same confines. Multiple sensors and movable stack guides (112,114) are provided to allow the transfer of the sheet stack from one tray to another and to report the status of each tray to the operator through a user interface.