Abstract: Apparatus for aligning a scanner assembly in a laser scanning unit for an image forming device. A MEMS torsion oscillator is attached to a spherical base that is received by a socket in a laser scanning unit. The pivotal center of the scanner coincides with the center of the spherical base such that the center of the scanner does not move as the scanner is aligned in the skew, process, and scan directions. In various embodiments, the aligned relationship of the spherical base to the socket is maintained by an adhesive, a through-bolt, or a plurality of spring-biased adjustment screws. The configuration and location of the adjustment screws is such that adjustment of the scanner assembly is accomplished without blocking the laser beam used for alignment.

Abstract: In bi-directional imaging, such as bi-directional printing, a driving mechanism scans a light beam through a scan path across an imaging window. A controller enables transmission of video data to a modulator when the light beam is positioned for imaging on the imaging window. Video data is transmitted to the modulator when the light beam is traveling in a forward direction or a reverse direction across the imaging window, whereby a modulated light beam is capable of producing an image when traveling in the forward or reverse directions. The controller adjusts scan durations or image rasterization rates to ensure that each scan is properly aligned with the prior and subsequent scan.

Abstract: A method reduces the Q factor of the resonant frequency response of a torsional oscillator system in a laser printer, where the Q factor is expressed as a function of the resonant frequency and 3 dB bandwidth of the frequency response. The frequency response of the torsional oscillator system is a function of at least a rotational inertia, a spring constant and a damping constant. The method includes the steps of decreasing the rotational inertia of the torsional oscillator system by a first factor, and decreasing the spring constant by a second factor that is substantially equal to the first factor. The method generally increases component yields, thereby reducing component costs. Also, laser printers using torsion oscillators having reduced Q factors may be used over a wider speed range. Conversely, a single laser printer model may be used at a single speed, rather than at speeds that vary due to variations in resonant frequency.

Abstract: A lens has a lens body (1), reinforcing extensions (3a, 3b) and a clear aperture (9) surrounded on top and bottom by lens body. The lens is suitable for spot scanning. The lens is made of a water absorbing material, such as most polymers, particularly acrylate polymers. Aluminum sheets as vapor barriers are attached on each side of the lens body. This results in excellent resistance to change or distortion in high humidity environments.

Abstract: A lens has a body (1), reinforcing extensions (3a, 3b) and a clear aperture (9) surrounded on top and bottom by lens body. The lens is suitable for spot scanning. The lens is made of a water absorbing material, such as most polymers, particularly acrylate polymers. Aluminum sheets as vapor barriers are attached on each side of the lens body. This results in excellent resistance to change or distortion in high humidity environments.

Abstract: An optical system particularly useful for color laser printers. Four imaging systems are provided, one for each color, black, magenta, cyan and yellow. Each imaging system has separate pre-scan and post-scan optical assemblies. Two scanning polygons are provided, and each scanning polygon is shared by two imaging systems. Both pre-scan optical assemblies shared by each scanning polygon are provided on the same side of the scanning assembly at substantially similar mirror image angles, to reduce scan image registration errors. The pre-scan and post-scan optical assemblies have improved adjustability.

Abstract: A lens has a lens body (1), reinforcing extensions (3a, 3b) and a clear aperture (9) surrounded on top and bottom by lens body. The lens is suitable for spot scanning. The lens is made of a water absorbing material, such as most polymers, particularly acrylate polymers. Aluminum sheets as vapor barriers are attached on each side of the lens body. This results in excellent resistance to change or distortion in high humidity environments.

Abstract: An optical system particularly useful for color laser printers. Four imaging systems are provided, one for each color, black, magenta, cyan and yellow. Each imaging system has separate pre-scan and post-scan optical assemblies. Two scanning polygons are provided, and each scanning polygon is shared by two imaging systems. Both pre-scan optical assemblies shared by each scanning polygon are provided on the same side of the scanning assembly at substantially similar mirror image angles, to reduce scan image registration errors. The pre-scan and post-scan optical assemblies have improved adjustability.

Abstract: The write lines of a color laser printer are maintained substantially equal throughout the printer's operation by an electronic control arrangement. At the factory, the write lines on all photoconductors of the color laser printer are calibrated to be substantially equal, and the ratio of each write line to a measuring line for each photoconductor is ascertained. During operation of the printer, the length of each of the measuring lines is periodically determined through counting the number of PELslice clock timing pulses produced from a PELslice clock operating at a fixed frequency determined during factory calibration. The length of the write line is determined by the product of the length of the measuring line and the factory calibrated ratio of the length of the write line to the length of the measuring line.

Abstract: A method of determining a position of a laser beam in an electrophotographic machine includes providing a sensor device having a laser beam receiving surface with a first edge and a second edge. The second edge is nonparallel to the first edge. The laser beam is scanned across the receiving surface in a scan direction perpendicular to a process direction. The laser beam intersects each of the first edge and the second edge of the receiving surface during the scanning. A time period between when the laser beam intersects the first edge and when the laser beam intersects the second edge of the receiving surface is measured. A process position of the laser beam along the process direction is calculated based upon the measured time period.

Abstract: The write lines of a color laser printer are maintained substantially equal throughout the printer's operation by an electronic control arrangement. At the factory, the write lines on all photoconductors of the color laser printer are calibrated to be substantially equal, and the ratio of each write line to a measuring line for each photoconductor is ascertained. During operation of the printer, the length of each of the measuring lines is periodically determined through counting the number of PELslice clock timing pulses produced from a PELslice clock operating at a fixed frequency determined during factory calibration. The length of the write line is determined by the product of the length of the measuring line and the factory calibrated ratio of the length of the write line to the length of the measuring line.

Abstract: The write lines of a color laser printer are maintained substantially equal throughout the printer's operation by an electronic control arrangement. At the factory, the write lines on all photoconductors of the color laser printer are calibrated to be substantially equal, and the ratio of each write line to a measuring line for each photoconductor is ascertained. During operation of the printer, the length of each of the measuring lines is periodically determined through counting the number of PELslice clock timing pulses produced from a PELslice clock operating at a fixed frequency determined during factory calibration. The length of the write line is determined by the product of the length of the measuring line and the factory calibrated ratio of the length of the write line to the length of the measuring line.