Lexmark International, Inc.

Daniel Eugene Pawley

Roger Steven Cannon

Martin Christopher Klement

Wilson Morgan Routt, Jr

Earl Dawson Ward, Ii

Timothy A Green

David Anthony Schneider

Philip Jerome Heink

Craig Palmer Bush

Thomas Campbell Wade

Robert L Paterson

Dana Allen Dodds

James Ronald Booth

Christopher Gregory Chee

Eric Wayne Westerfield

David John Mickan

Danny Wayne Peters

Mark Edwin Kirtley Lund

Philip Edwin Riggs

E Dawson Ward

An imaging device scan unit, including an oscillator oscillating in a predetermined oscillation pattern; a light source generating a light beam for deflection by the oscillator and including a forward sweep portion when the oscillator moves in a first direction of the oscillation pattern and a reverse sweep portion when the oscillator moves in a second direction different from the first direction thereof; and components defining at least two optical paths for the light beam, the forward sweep portion of the light beam passes through a first optical path and the reverse sweep portion of the light beam passes through a second optical path, the second optical path reverses a sweep direction of the reverse sweep portion of the light beam such that the forward sweep portion and the reverse sweep portion of the light beam are in the substantially same direction when exiting the scan unit.

Scan unit for an imaging device and methods of using same

In an electrophotographic (EP) device, methods and apparatus include determining a delay of one or more sensors (hsync) to accurately know when to start the process of scanning latent images. In one aspect, the sensor includes a leading and trailing edge defined along a direction of laser beam scan travel. Determining the delay includes learning a position of a laser beam on the sensor at a time when a controller connected to the sensor receives a signal from the sensor indicating the sensor is being sufficiently impinged upon by the laser beam. It also includes learning a latest possible position of the laser beam along the direction of laser scan travel where the laser beam can be turned on and still have the sensor assert a signal indicating it has been sufficiently impinged upon by the laser beam. Bi-directionally scanning EP devices are also disclosed, including controllers, photoconductors, sensors, etc.

Methods and apparatus for ascertaining sensor signal delay in an electrophotographic device

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.

Angular adjustment of MEMS torsion oscillator scanner

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.

Bi-directional scanning and imaging with scanning compensation

Multiple light beams are reflected by a resonant oscillator through an optical system onto light sensitive drums of a printing system. Information is encoded onto the beams, and an image is printed based on the encoded information. Preferably four beams and four drums are used to print four colors. The oscillator includes an oscillating plate mounted on the torsion springs for resonant oscillation. A magnet is mounted on the oscillating plate and an oscillating magnetic field oscillates the magnet and the plate. Sensors detect the position of at least one of light beam to synchronize the operation and speed of the encoder, drums and oscillator. The oscillator may include multiple reflective surfaces on one or more sides of an oscillating plate, and one or more beams may be reflected from each surface.

Galvonometric scanning and imaging with multiple beams reflected from an oscillator

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. The method also provides for greater freedom of movement of the operating point of the printer during printer development.

Method and apparatus for reducing Q factor in an oscillating laser scanner

A lens has a lens body (), reinforcing extensions () and a clear aperture () 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.

Humidity tolerant scan lens

An optical scanning system including a resonant oscillating device having a first magnetic field and a mirrored surface. The system includes first and second light sources for directing first and second beams of light to the mirrored surface of the resonant oscillating device to provide first and second reflected scan beams. The second reflected scan beam is offset a first distance from the first reflected scan beam. A second magnetic field is included for interacting with the first magnetic field to provide torque to the resonant oscillating device for scanning the first and second reflected scan beams across a surface to provide first and second scan lines on the surface substantially simultaneously as the resonant oscillating device oscillates under the influence of the first and second magnetic fields. The optical scanning system is effective to increase scan efficiency of the resonant oscillating device over that of a system using a single light source.

Resonant oscillating scanning device with multiple light sources and dual scan path

Resonant oscillating scanning device with multiple light sources

An imaging system in which a modulated light beam is reflected by a reflection surface oscillated by a torsion oscillator, such imaging system being capable of operating dynamically to adjust to the change in resonant frequency of the torsion oscillator. The resonant frequency of the torsion oscillator varies with ambient temperature and with other factors, such as amount of use. Sensors sense the sweep of the light beam to determine a currently existing resonant frequency of the torsion oscillator. The rate of modulation of the beam by a laser is adjusted to conform the modulation in the sweep direction to the desired resolution of the image. Similarly, the speed of movement of a surface being imaged is adjusted to conform the modulation to the desired resolution in the direction perpendicular to the sweep direction. Optionally, the electrical drive frequency of the torsion oscillator may also be adjusted to correspond with the currently existing resonant frequency during physical operation. The resulting image is improved in visual quality.

Oscillator imaging with control of media speed and modulation frequency

An image scanning apparatus and a torsion oscillator are capable of operating across a dynamic range of possible operating frequencies. The image scanning apparatus uses a light source to produce a light beam, and the oscillator scans the light beam through a scanning pattern. The oscillator includes a plate member having a non-rectangular shape. At least one magnet is disposed on the plate. A surface of the plate member includes a reflective surface for reflecting a light beam. A frame is disposed in a spaced apart relation to a lower surface of the plate member. The frame includes at least one coil configured to induce an electromagnetic force on the at least one magnet to thereby oscillate the reflective surface to a rotational angle of oscillation at an oscillation frequency. The system also includes an imaging surface disposed in the path of the scanning pattern so that the light beam scans across the imaging surface, and a mechanical drive to move the imaging surface. A control system controls electric current provided to the at least one coil to achieve the oscillation.

Stationary coil oscillator scanning system

An image scanning apparatus and a torsion oscillator are capable of operating across a dynamic range of possible operating frequencies. The image scanning apparatus uses a light source to produce a light bean, and the oscillator scans the light beam through a scanning pattern. The oscillator includes a plate member having a non-rectangular shape. At least one magnet is disposed on the plate. A surface of the plate member includes a reflective surface for reflecting a light beam. A frame is disposed in a spaced apart relation to a lower surface of the plate member. The fame includes at least one coil configured to induce an electromagnetic force on the at least one magnet to thereby oscillate the reflective surface to a rotational angle of oscillation at an oscillation frequency. The system also includes an imaging surface disposed in the path of the scanning pattern so that the light beam scans across the imaging surface, and a mechanical drive to move the imaging surface. A control system controls electric current provided to the at least one coil to achieve the oscillation.

A lens has a body ( ), reinforcing extensions ( ) and a clear aperture ( ) 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.

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.

Growing community of inventors

Louisville, KY, United States of America

Daniel Eugene Pawley