Abstract:
Laser pulses are selected from a group of closely spaced laser pulses with an optical modulator by adjusting pulse timing relative to an impingement interval. An adjusted pulse is moved from an impingement interval to a non-impingement interval and is blocked. The blocked laser source is stabilized by running nearly continuously. Pulse selection with multiple laser sources is achieved with a single acousto-optic modulator.
Abstract:
Electrophotographic print system, comprising a photosensitive medium, and a laser array being provided with a plurality of laser diodes arranged to emit light onto the photosensitive medium for varying an electrical potential on a surface of the photosensitive medium, and a plurality of heat dissipation diodes, each heat dissipation diode being arranged in proximity to a corresponding laser diode, wherein each laser diode and the corresponding heat dissipation diode are coupled to a common drive circuit and are arranged in opposite current flow directions with respect to each other, so that in use the current flows either through the laser diode or through the heat dissipation diode depending on the current flow direction in the drive circuit.
Abstract:
An optical beam is selectively output towards a scanner in accordance with image data for a scan line of an image. The optical beam has a beam irradiance distribution that is elliptical in shape. The optical beam passes through an aperture stop, ordinarily creating side lobes within a focus irradiance distribution of the optical beam. The scanner scans the optical beam to form the scan line on a photosensitive surface by selectively exposing positions along the scan line in accordance with image data. The optical beam is modified before it reaches the photosensitive surface to substantially remove the side lobes that have been created within the focus irradiance distribution and/or to substantially prevent the side lobes from being created within the focus irradiance distribution of the optical beam.
Abstract:
Link processing systems and methods use controlled two dimensional deflection of a beam along an optical axis trajectory to process links positioned along and transverse to the trajectory during a pass of the optical axis along the trajectory. Predictive position calculations allow link blowing accuracy during constant velocity and accelerating trajectories.
Abstract:
A correction method for correcting unintended spatial variation in lightness across a physical image produced by a xerographic process, the method comprising producing a test image using the xerographic process, measuring a difference between actual lightness and intended lightness across at least part of the test image, and varying the light source level used subsequently in the xerographic process to correct for the measured unintended difference.
Abstract:
Skew compensation apparatus for compensating for skew of a multi-beam scanning source, comprises: delay commencement detector(s) for detecting the start of a beam scanner position, position detectors for detecting the position of the multiple beams at a predefined interval following the commencement, so that the position indicates skew of the respective beam, and compensating electronics for automatically inserting a compensation for the skew by altering a delay into a timing signal for switching the respective beam. The commencement detector can be an existing start of scan detector and the apparatus can be built into the writing head, particularly at the conjugate location to the focal plane or at the focal plane of a laser printer or the like to provide a self-calibrating printer.
Abstract:
A high-speed method and system for precisely positioning a waist of a material-processing laser beam to dynamically compensate for local variations in height of microstructures located on a plurality of objects spaced apart within a laser-processing site are provided. In the preferred embodiment, the microstructures are a plurality of conductive lines formed on a plurality of memory dice of a semiconductor wafer. The system includes a focusing lens subsystem for focusing a laser beam along an optical axis substantially orthogonal to a plane, an x-y stage for moving the wafer in the plane, and a first air bearing sled for moving the focusing lens subsystem along the optical axis. The system also includes a first controller for controlling the x-y stage based on reference data which represents 3-D locations of microstructures to be processed within the site, a second controller, and a first voice coil coupled to the second controller for positioning the first air bearing sled along the optical axis also based on the reference data. The reference data is generated by the system which includes a modulator for reducing power of the material-processing laser beam to obtain a probe laser beam to measure height of the semiconductor wafer at a plurality of locations about the site to obtain reference height data. A computer computes a reference surface based on the reference height data. A trajectory planner generates trajectories for the wafer and the waist of the laser beam based on the reference surface. The x-y stage and the first air bearing sled controllably move the wafer and the focusing lens subsystem, respectively, to precisely position the waist of the laser beam so that the waist substantially coincides with the 3-D locations of the microstructures within the site. The system also includes a spot size lens subsystem for controlling size of the waist of the laser beam, a second air bearing sled for moving the spot size lens subsystem along the optical axis, a third controller for controlling the second air bearing sled, and a second voice coil coupled to the third controller for positioning the second air bearing sled along the optical axis.
Abstract:
A high-speed method and system for precisely positioning a waist of a material-processing laser beam to dynamically compensate for local variations in height of microstructures located on a plurality of objects spaced apart within a laser-processing site are provided. In the preferred embodiment, the microstructures are a plurality of conductive lines formed on a plurality of memory dice of a semiconductor wafer. The system includes a focusing lens subsystem for focusing a laser beam along an optical axis substantially orthogonal to a plane, an x-y stage for moving the wafer in the plane, and a first air bearing sled for moving the focusing lens subsystem along the optical axis.
Abstract:
Apparatus for detecting concentrations of colored toner particles in the presence of black or other absorbing toner particles including a light source, a light detector having a field of view of less than about .+-.10 degrees and preferably less than .+-.5 degrees, apparatus for supplying a dispersion of colored toner particles optionally containing undesirable contamination by black toner particles between the light source and the detector and computing circuitry operative for determining the concentration of the colored toner particles utilizing output from the light detector.