Abstract:
Described are techniques for preventing the forces attributable to shrinkage of print media from shifting print media on the media-carrying belt in the vicinity of the print zone. In one approach, a “hold zone” is identified immediately upstream of the print zone. In the hold zone, a mechanism is employed for securing the media to be immovable relative to the belt. The hold mechanism provides sufficient force to overcome tension transmitted to the dry portion of the media as the remaining portion shrinks. In one embodiment, the hold mechanism is a roller that pinches the media against the belt. In another embodiment, the amount of vacuum pressure applied to the belt is regulated so that the suction force applied to the media in the hold zone is greater than the suction force applied to the media in the portion upstream of the hold zone.
Abstract:
A method and apparatus for ink-jet drop generator ink drop characteristics uses a drop detector target mounted in the printing zone of a hard copy apparatus. The detector target includes a matrix of individual elements sized approximately the same as pixel targets in printing operations. A detector target is mounted adjacently to the paper path of the apparatus such that test firing can be accomplished prior to each swath scan across the print media. By pre-firing nozzles to be used in the next swath at the detector target, actual trajectory errors and drop volumes can be analyzed in real-time. Alternate embodiments and methods are described.
Abstract:
An embodiment of a drying apparatus for drying ink deposited onto media includes an electromagnetic energy source to generate electromagnetic energy. The embodiment of the drying apparatus also includes a rectangular waveguide coupled to the electromagnetic energy source. The rectangular waveguide includes slots in the axial direction of the rectangular waveguide on opposite sidewalls corresponding to the largest sides forming a cross section of the rectangular waveguide. The electromagnetic energy source is configured to establish a TE01 mode within the rectangular waveguide, resulting in an electric field substantially perpendicular to the longitudinal axes of fibers within the media and thereby reducing power dissipated within the media while providing sufficient power for drying the ink during a drying operation.
Abstract:
A method and apparatus for ink-jet drop generator ink drop characteristics uses a drop detector target mounted in the printing zone of a hard copy apparatus. The detector target includes a matrix of individual elements sized approximately the same as pixel targets in printing operations. A detector target is mounted adjacently to the paper path of the apparatus such that test firing can be accomplished prior to each swath scan across the print media. By pre-firing nozzles to be used in the next swath at the detector target, actual trajectory errors and drop volumes can be analyzed in real-time. Alternate embodiments and methods are described.
Abstract:
A print media level sensor and method for determining a height of a stack of print media for use in printing devices are disclosed. An embodiment of a print media level sensor includes a print media stack follower configured to contact a top of a stack of print media and remain in contact with the top as a height of the stack changes. The print media stack follower also includes encoded data representative of a plurality of heights of the stack of print media. The print media level sensor additionally includes a decoder configured to read encoded data on the print media stack follower and output a signal representative of the encoded data. The print media stack follower may further include a computing device that receives the signal representative of the encoded data from the computing device and converts the signal representative of the encoded data into a signal representative of the stack height. An embodiment of a method includes tracking a height of a stack of print media via a print media stack follower and encoding data representing a plurality of different stack heights via the print media stack follower. The method additionally includes decoding the encoded data and generating a signal representative of the encoded data. The method may further include converting the signal representative of the encoded data into a signal representative of the height of the stack. Further characteristics and features of this apparatus and method are disclosed herein, as are exemplary alternative embodiments.
Abstract:
A media handling system having an endless belt which carries a media sheet through a print zone achieves improved media advance accuracy by including closed loop feedback control. The position of either a drive shaft which rotates the endless belt or the endless belt itself is monitored to provide feedback to a drive motor. The drive motor is linked to the drive shaft through a gear train. The endless belt is rotated by the drive shaft, either directly, or through rollers mounted to the drive shaft.
Abstract:
A shuttling media movement system moves media in a hardcopy device, such as an inkjet printing mechanism, a facsimile machine or a multi-function device. The shuttling media movement system has a first member with a first set of fingers for periodically supporting the media, and a second member having a second set of fingers for periodically supporting the media. A motor drive is coupled to the second member to periodically interleave the second set of fingers into and out of engagement with the first set of fingers to move the media with respect to the first member in the interaction zone. Vacuum forces or electrostatic forces are used to periodically grip the media against the sets of fingers. A hardcopy device is provided with such a shuttling media movement system, along with a method for moving media in an interaction zone of a hardcopy device.
Abstract:
A shifted element printing/scanning routine coordinated with media advance through an interaction zone of hardcopy device is provided for inkjet printing mechanisms, scanners or multi-function hardcopy devices. A method is provided of coordinating operation of a reciprocating head with media advance. The head has plural interaction elements, which may be ink-ejecting nozzles in a printing mechanism, or image receptors in a scanning mechanism, with the interaction elements being arranged in a linear array to selectively interact with media. A hardcopy device has a rotating media advancing member, a reciprocating head carrying the interaction elements, an encoder having indicia to track media advance, and a sensor that interprets the encoder indicia and generated a media position signal. A controller adjusts the media advance and shifts operation of selected interaction elements to other interaction elements along the linear array to avoid an indeterminate region of the position signal where the media position cannot be ascertained.
Abstract:
Automatic print rate-controlling and pen-servicing method and apparatus are described for power management and for determining appropriate servicing intervals for plural-pen ink-jet printers. The preferred method involves counting the number of drops of ink that are fired from each of plural pens in the printer's printhead carriage and optionally calculating the pen firing rate such that printer throughput can be controlled to limit time-averaged power and such that pen servicing frequency can be based upon the need for such servicing. The counts are maintained in memory connected, for example, with the printer's microcontroller, as are parameters that the microcontroller uses to determine appropriate drop count-based print rate controlling or pen servicing that reduce printer throughput only to the extent necessary. Particularly, the pens are serviced when any of the counts is within a predefined finite range of a predefined number or no later than when any of the counts exceeds a corresponding predefined number. The preferred apparatus includes a drop counter, a service station for wiping and spitting plural pens within a printhead carriage and a controller responsive to the drop counter to control the printing rate and to move the printhead carriage into operative association with the service station based upon drop count, firing rate, time-averaged power capability, printhead location and other predetermined criteria.
Abstract:
The encoder scale has features to be automatically read by a single-channel sensor of the device to determine position of a carriage that is part of the device and moves bidirectionally across the sheet. These features include a first group of many graduations formed in a single row along the substrate; and a second group of many graduations also formed in the same row along the substrate and interspersed among those of the first group over at least a distance that corresponds approximately to the full transverse dimension of the sheet. The scale also includes some provision for automatically distinguishing --by the single-channel sensor of the image-related device--between graduations of the first and second groups. This provision includes, for each graduation of the second group, some feature (such as width) that is distinctive in relation to the graduations of the first group. The invention also provides the image-related device, with the carriage operating bidirectionally to print or read image details onto or from the sheet, and with the encoder scale incorporated as well as a single-sensor subsystem for detecting the individual graduations of both sets--and also including a single-channel subsystem that makes use of the two groups of graduations for two distinct purposes, respectively.