Abstract: A color printer uses multiple linear arrays of surface emitting lasers of differing wavelengths and polarization states to simultaneously expose widely separated positions on the same or different photoreceptors. Each array is imaged by the same optical system to the photoreceptor. The multiple linear arrays can be closely spaced in a monolithic structure.

Abstract: In a raster output scanner (ROS) of a xerographic printing device, the location of an apparent source of the light beam is adjusted within a light emitting apparatus to enable spot position control anywhere along a scanline to insure subline registration of an image. This is accomplished by placing the apparent source location of the light emitting apparatus on a movable plate. The apparent source is located at the position from which a light beam is emitted from an output end of a laser source or waveguide connected to the laser source. The movable plate is adjusted by actuators which may be comb drives, thermal bimorphs or piezoelectric drive mechanisms.

Abstract: The optical path length of a raster output scanning (ROS) system is minimized by the use of a laser beam source for emitting a light beam with an enlarged divergence ratio. A super-elliptic light source beam with at least an 8:1 elliptic ratio of the major cross-scan axis to the minor scan axis will minimize the optical path length of a raster output scanning (ROS) system. The large divergence ratio of the super-elliptic light beam reduces the required focal lengths in the ROS optics while maintaining the desired numerical apertures and high energy throughput.

Abstract: In a raster output scanning system (ROS) of a xerographic printing device, a plurality of input optical channels direct at least one of a plurality of light beams onto separate facets of a deflector, which may be a rotating polygon mirror. The deflector deflects the light beams onto disparate optical paths. An optical system located on the disparate optical paths directs at least one of the light beams onto each of first, second, third and fourth image receiving locations. The image receiving locations may comprise a plurality of photoreceptors.

Abstract: A raster scanning optical system and method for adjusting a scan line location on a light receiving member by a desired amount. A photoreceptor receives a light beam as the photoreceptor is advancing in a slow scan direction. A polygon mirror scans the light beam across the photoreceptor at a scan line location extending in a fast scan direction. A light transmissive plate is located in the path of the light beam between the polygon mirror and the photoreceptor. The light transmissive plate is adjusted by an adjusting device to displace the scan line location on the photoreceptor by the desired amount in a direction parallel to the slow scan direction.

Abstract: A raster scanning optical system and method for adjusting the pixel placement of light beams being scanned across an image receiving device. A spot velocity of a first laser beam is measured and then a spot velocity of a second laser beam is measured. From these measurements, the pixel positions of each of the beams can be determined. The firing rate of the second laser beam is then adjusted to adjust the pixel placement of the second beam. This helps avoid problems caused by tangentially offset laser diodes that scan with varying spot linearities.

Abstract: A raster scanning optical system and method emits a first light beam and a second light beam onto a light receiving member. A scanning device has at least one facet for reflecting the first and the second light beams to the light receiving member. A light transmissive plate is located in a path of the first light beam between the first light emitting device and the scanning device. The light transmissive plate adjusts the sagittal direction and the tangential direction of the first light beam by a desired amount so that the first and second light beams are reflected from positions of the scanning device that are closer to each other and parallel in both the sagittal and tangential meridian.

Abstract: A nonmonolithic, multiple wavelength laser array having closely spaced lasing elements which are accurately spaced both in a plane perpendicular to the optical axes of the laser beams and along the optical axes. The laser array includes a plurality of lasing elements mounted on a high thermal conductivity spacer. The spacer has a front surface angled relative to the optical axes of the lasing elements, and parallel mounting surfaces. The mounting surfaces and front surfaces join to form front edges. The laser elements mount such that the front facet of each lasing element is aligned with an associated front edge. Beneficially, either the spacer is electrically conductive, or the spacer is coated with a layer of conductive material.The laser array can be used in a printer to offset the laser elements to correct for the wavelength dependency of the printer's optical system.

Abstract: In a raster scanning system (ROS) of a multi-station xerographic printing device, the image height of each of the images formed from a plurality of clustered laser beams having dissimilar wavelengths is changed so that the image heights approximate each other. This is accomplished by passing one or more of the light beams through light transmissive plates having a predetermined thickness and index of refraction. The light transmissive plates can be optical filters that also one used to separate the clustered light beams based upon their wavelength and/or polarization.

Abstract: The present invention is a novel raster output scanner (ROS) configuration that employs modulated laser diodes as the light source. Each laser diode is coupled to a dedicated driver that modulates the light beam according to digital video signal data. The present invention employs a single-channel acoustic-optic cell that deflects the multiple beams to maintain proper facet tracking. A single transducer is coupled to the single-channel acoustic-optic cell that generates the necessary acoustic wave to maintain proper tracking.

Abstract: A raster scanning system has an image receiving device that receives a light beam, a scanning device for scanning the light beam across the image receiving device and a mirror located in the path of the light beam between the scanning device and the image receiving device for directing the light beam to the image receiving device. An adjusting device adjusts a curvature of the mirror to correct for bow of the light beam on the image receiving device.

Abstract: A system for eliminating differential scan line bow from raster output scanners aligns at least the chief exit ray of each scanning light beam with the system axis. By aligning the chief exit rays to be essentially parallel to the system axis, the overall bow is reduced, and the bow of different scan lines is essentially identical. Thus, bowed scan lines from different stations in a multi-station printer, or from different passes in a multi-pass printer are generally identical and aligned.

Abstract: The present invention is a thin film coating that may be applied to various optical elements and a method for controlling the size of the imaging spot from multiwavelength sources in an optical path. A selective optical element made in accordance with the principles of the present invention comprises an optical surface. Upon the surface, thin film coatings are deposited that define zones of transmission, each zone transmits a desired wavelength band. Beyond this zone, the surface is effectively opaque to a specified wavelength band. The zones for each wavelength are individually calculated to give an effective aperture for each wavelength such that the spot size for all wavelengths meet user specifications.

Abstract: An imaging device and method for projecting imaged light according to print data onto an imaging medium includes a light source, an optics system receiving light from the light source, and at least one modulator having a plurality of individually addressable reflective elements. The optics system images or focuses the light source onto the at least one modulator and the at least one modulator selectively modulates a portion of the light onto the imaging medium according to the print data. The optic system includes a condenser lens positioned between the light source and the at least one modulator and an imaging lens be positioned between the at least one modulator and the imaging medium. A numerical aperture of the condenser lens is set to be equal to a numerical aperture of the imaging lens to critically illuminate the modulator. The light source may include a plurality of light emitting elements.

Abstract: The present invention is a scanning system and a novel method for compensating for the variations in the output power of the beam from an A-O cell. The novel method involves varying the amount of drive current through the laser diode in such a fashion as to compensate for the loss of power due to diffraction inefficiencies. The amount of driving current is dependent upon the amount of power desired in the output beam from the A-O cell. The system and method of the present invention sets the output power from the A-O cell to a desired value. As the diffraction efficiency increases at other portions of the scan, the drive current is cut appropriately to compensate for the increased efficiency; thus keeping the output spot power at the desired value. Likewise, as the diffraction efficiency decreases at other portions of the scan, the drive current should be increased to compensate for the decrease in efficiency; thereby maintaining the desired value.

Abstract: A raster output scanner (ROS) laser diode architecture enables a plurality of laser diodes, which produce light beams at separated wavelengths, to be spaced a convenient distance apart for a multistation printer, by arranging the diodes in a line that is parallel to the fast scan direction of the ROS. Wavelength discriminating optics are used to alternately separate and reflect the light beams reflected from a single ROS polygon mirror. These separated and reflected beams then expose their associated photoreceptors with a rasterized image that is subsequently transferred to a support medium such as plain paper and developed into an image.

Abstract: A single raster scanning system (ROS) with a rotating mirror, beneficially a polygon mirror, and a single set of scan optics suitable for use in a multistation xerographic printer. A plurality of clustered laser beams from the same spatial location, but of dissimilar wavelengths, are deflected using a common mirror surface area and are subsequently separated by a plurality of optical filter. The separated laser beams are then directed onto associated photoreceptors such that their optical path lengths from the source location to their photoreceptors are substantially the same.

Abstract: A direct focussed gas laser 9 wherein the last surface 40, 48A, 48B of the output mirror, in the case of a laser where the mirrors are integral to the ends of the laser tube envelope, is shaped such that it produces a cone 42, or wedge shaped 70, beam. A spherical surface provides a cone-shaped beam, while cylindrical surfaces produce a wedge shaped beam. In the case of a Brewster type laser, the envelope-enclosing windows are correspondingly shaped.

Abstract: A rotating polygon-type laser scanning subsystem is integrated with a photocopying subsystem to provide a relatively high quality, economical and compact multi-function document processor. To optimize the performance of the document processor, the laser scanning subsystem preferably is a symmetrical, double pass, underfilled system, and the photocopying system preferably is a light/lens xerographic system. Shared optics are used to reduce the cost, complexity and size of the document processor.

Abstract: To provide a relatively compact and linear underfilled multifaceted rotating polygon beam scanning system, there are imaging optics for bringing a input light beam to a tangentially extending line-like focus on successive facets of a rotating polygonal scanning element and for restoring the light beam reflected from the facets to a generally circular focus on an image plane. Each of the facets subtends a sufficient angle about the axis of rotation of the scanner to ensure that the input beam remains fully seated on a single facet while the reflected beam is being scanned through a desired scan angle. Furthermore, improved linearity is achieved because the scanning system is symmetrical in the tangential and sagittal planes at all points between the imaging optics and the polygonal scanning element.