Abstract: An indexing stop is moveable relative to a printer carriage that carries cartridges for printing a swath at a time. Part of the stop is in the path that the carriage travels. The stop is advanced while the cartridges print one, "first" swath (that is, while the carriage is stationary). The stop is advanced to a position corresponding to the location where the carriage is to be moved to facilitate printing of the next, "second" swath. Once the first swath is printed, the carriage is controlled to move toward and abut the stop, thus arriving in the location for printing the second swath. The stop simplifies and speeds the carriage movement between swaths, thereby increasing printer throughput.

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.

Abstract: A monitoring system monitors a pressure wave developed in the surrounding ambient environment during inkjet droplet formation. The monitoring system uses either acoustic, ultrasonic, or other pressure wave monitoring mechanisms, such as a laser vibrometer, an ultrasonic transducer, or an accelerometer sensor, for instance, a microphone to detect droplet formation. One sensor is incorporated in the printhead itself, while others may be located externally. The monitoring system generates information used to determine current levels of printhead performance, to which the printer may respond by adjusting print modes, servicing the printhead, adjusting droplet formation, or by providing an early warning before an inkjet cartridge is completely empty. During printhead manufacturing, an array of such sensors may be used in quality assurance to determine printhead performance. An inkjet printing mechanism is also equipped for using this monitoring system and a monitoring method is also provided.

Abstract: An optical sensor module for identifying characteristics of printed ink jet images on printing media residing in a media plane. The module has a chassis and a connected illumination source and detector spaced apart from the media plane. An integral optical element is positioned between the image plane and the illumination source and detector. The optical element has a first portion having a first optical characteristic positioned on a first optical path between the illumination source and a selected region of the media plane, and a second portion having a second optical characteristic different from the first optical characteristic and positioned on a second optical path between the illumination source and the selected region. The optical element may include diffractive optics, fresnel lenses, and conventional lenses formed of transparent plastics to steer, focus and diffuse light onto the selected region and return it efficiently to the detector.

Abstract: A position encoder system is provided, such system including a code wheel, a pair of sensors, a counter, and a processor capable of identifying the correlation between separately identified markings of the code wheel. The identified correlation is indicative of code wheel accuracy, and thus is used to correct error in any angular position determined using the code wheel.

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.

Abstract: In DC-DC switching converters of the single-ended primary inductance (SEPIC) type, using a high frequency transformer to isolate the load from the AC power line is difficult because its leakage inductance causes serious circuit problems. In the invention, an additional coupling capacitor provides the required DC isolation without affecting circuit performance. The total coupling capacitance may be chosen to limit the power line frequency leakage current to a safe value.

Abstract: The present invention relates to Ink Level Detection in a Pressure Regulated Pen. A liquid level detector for a liquid containment device, such as an ink-jet pen, provides a signal indicative of a lowering level of liquid in the containment device. In exemplary embodiments, a refillable or replaceable ink reservoir supplies ink to the printhead of the pen under pressure. Electrical or electromagnetic devices are used individually or in combination with a pressure regulator apparatus to sense a back pressure in the containment device after the reservoir has gone dry to trigger a signal indicating a low or out-of-ink condition.

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.

Abstract: Carriage and paper motion overlap method and apparatus are described. The preferred method utilizes carriage ramp-down and unidirectional, constant-speed periods of time to advance paper via the printer's paper advancement mechanism while avoiding current-intensive ramp-up periods of time during which demands on the printer's power supply are high. The printer's controller is programmed to implement preferably concurrently operable processes one of which controls paper movement and the other of which controls carriage movement. The processes signal one another based upon their monitoring of defined conditions of the printer and the print buffer, and by setting and clearing a flag.