摘要:
A printing device comprises a print head, imaging member, and a moveable sensor array. The print head is configured to deliver marking material to the imaging member as it moves in a process direction. The linear sensor array comprises a plurality of photo sensors configured to scan the imaging member. The photo detectors of the linear sensor array define a sensor axis that is substantially perpendicular to the process direction. The linear sensor array is configured to move along the sensor axis between a first position where the sensor array scans one portion of the imaging member and a second position where the sensor array scans another portion of the imaging member. If a fault is detected during calibration of the sensor array, the moveable sensor array may be used to determine whether the source of the fault rests with the imaging member or the sensor array.
摘要:
A semi-automatic exit window cleaner which includes a wiper for contacting an exit window. The wiper attaches to a wiper operation mechanism which swipes the wiper across the exit window when an operator accessed compartment or drawer is moved. Beneficially, the wiper mechanism is comprised of a cable which is spaced between two pulleys, one of which also connects to a gear or other rotation train.
摘要:
A method and apparatus is provided for lateral registration of image exposures on photoreceptive belts subject to lateral deviation from linear travel. In one embodiment, a plurality of Raster Output Scanner (ROS) imagers in a digital color printer are positioned so as to form successive images on the surface of the belt. A plurality of split cell photodetectors are positioned beneath the belt, one each associated with each of the ROS imagers. An aperture is formed in the belt in a non-image area, but in alignment with the detectors. Scan lines from each ROS unit are periodically visible through the aperture and illuminate the photodetector. The outputs from each of the photodetector photosites are compared and lateral belt movement errors thereby identified. Appropriate correction signals are generated to maintain the correct lateral registration.
摘要:
A Raster Output Scanner (ROS) color printer is formed by providing several ROS imagers adjacent image exposure locations of a photoreceptor belt. Each ROS imager forms a separate color image in response to video input signals with each color image superimposed in registration over the previously formed images. Registration in the process direction is enabled by a quad cell photosensor whose output is continually compared to determine whether process registration deviations from a previously established position are necessary. Correction signals are generated in an iterative fashion until a preselected process registration position is re-established. The quad cell detector is also used for a second function; to produce the start and end of scan signals which enable image registration in the cross-process direction.
摘要:
Compensation for process direction photoreceptor motion in a Raster Output Scan system is provided by moving the cylinder lens located between the laser source and a rotating spot scanning mechanism, e.g., a polygon. The cylinder lens is moved in the process direction in response to error signals generated by a SOS detector and timing marks on the photoreceptor drum surface, or an encoder on the drum shaft. The lens movement is obtained by sending motion error signals to a piezoelectric actuator which increases in length to impart the desired motion to the cylinder lens.
摘要:
The efficiency of a raster output scanning system is enhanced by replacing a folding mirror cylindrical lens in the pre-polygon optics with a single cylindrical mirror. The mirror is designed and positioned to direct a beam input in a different direction along an optical path and to focus the beam in the sagittal plane at an optimum line at the facet surface. The mirror is arranged so that the focus line is parallel to the angle the mirror makes with the system optical axis and coincident with the vertical plane of the polygon facets upon which it impinges.
摘要:
A diode laser structure is thermally stabilized by passing current through heater strips along the sides of the diode laser cavity. The thermally stabilized diode laser structure comprises a first confinement layer and a substrate of one conductivity type, an active layer, a second confinement layer and a contact layer of an opposing conductivity type. Disordered regions extend from the contact layer through to the first confinement layer defining diode laser cavities. Resistive regions are formed within the disordered regions. Individual contacts on the contact layer aligned with each diode laser cavity inject current through the diode laser cavity to the contact on the substrate causing emission of coherent light through the edge of the diode laser structure. Individual contacts on the contact layer aligned with resistive region inject current through the resistive region to the contact on the substrate causing generation of heat. The resistive region within the disordered region forms a heater strip and adjacent heater strips maintain the temperature within the diode laser cavity inbetween the adjacent disordered regions of the heater strips. The resistive can be replaced with a diffused region to provide a forward biased p-n junction to form the heater strip. The contacts for the laser cavity and the heater strips can be interdigitated.
摘要:
A system and method for controlling the cross-process position of ink print heads including identifying a first roll error frequency related to a circumference of a first roll, identifying a first roll error phase with respect to a reference location along a process path, identifying a first roll error amplitude of cross-process motion, identifying a second roll error frequency related to a circumference of a second roll, identifying a second roll error phase with respect to the reference location, identifying a second roll error amplitude of cross-process motion, and controlling the cross-process position of a first and second print head based upon the identified first roll error frequency, first roll error phase, first roll error amplitude, second roll error frequency, second roll error phase, and second roll error amplitude, wherein the first print head is axially spaced apart from the second print head along the process direction.
摘要:
A system and method for controlling the cross-process position of ink print heads including identifying a first roll error frequency related to a circumference of a first roll, identifying a first roll error phase with respect to a reference location along a process path, identifying a first roll error amplitude of cross-process motion, identifying a second roll error frequency related to a circumference of a second roll, identifying a second roll error phase with respect to the reference location, identifying a second roll error amplitude of cross-process motion, and controlling the cross-process position of a first and second print head based upon the identified first roll error frequency, first roll error phase, first roll error amplitude, second roll error frequency, second roll error phase, and second roll error amplitude, wherein the first print head is axially spaced apart from the second print head along the process direction.
摘要:
This invention relates to a method for the calibration of linear array photo sensors operating in a specular reflection mode. Errors may be introduced when a highly diffused image is measured by the linear array photosensor that was calibrated in a specular mode. These errors result in artifacts such as streaks in the captured image. The method measures non-uniformity errors using a highly diffuse white reflective surface, and then applies an appropriate scaled pixel-wise correction factor to the image when the sensor is used in the specular mode.