Transient Vibration of a Laser Scanner Motor in Digital Electrophotography

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    3 Citations (Scopus)

    Abstract

    This paper describes a transient vibration during start-stop operation of a polygonal mirror scanner motor in a laser printer. Two types of abnormal vibration take place in the rotor driven by a flat-type brushless DC motor and supported by a passive thrust magnetic bearing and a radial air bearing. One is an axial displacement and vibration and another is a radial dry-contact at very low speed region. From results of theoretical and experimental investigations, the following characteristics and countermeasures have been deduced: (1) Repulsive magnetic force induced between the stator coils and rotor magnet of the motor causes the axial static displacement and the axial transient vibration. Soft start-stop scheme of the motor current is effective to reduce the axial vibration. (2) The rotor is statically unstable in the radial direction at very low speed region. This instability occurs because the stiffness of the air bearing is not induced without rotation and it is small at the very low speed region, whereas the magnetic negative stiffness of the magnetic bearing is existent even at a zero speed. Dry contact between the rotor and the stator shaft at the air bearing is induced at the speed lower than a threshold. Since the dry contact reduces the lifetime of the air bearing, it is preferable to avoid frequent start-stop operations and to keep the rotor speed higher than the threshold. The instability is reduced to adopt the magnetic bearing composed of a pair of permanent magnets.

    Original languageEnglish
    Title of host publicationSociety for Imaging Science and Technology: Image Processing, Image Quality, Image Capture, Systems Conference
    Pages17-21
    Number of pages5
    Publication statusPublished - 2000
    EventFinal Program and Proceedings: IS and T's Annual Conference - Portland, OR
    Duration: 2000 Mar 262000 Mar 29

    Other

    OtherFinal Program and Proceedings: IS and T's Annual Conference
    CityPortland, OR
    Period00/3/2600/3/29

    Fingerprint

    Bearings (structural)
    Rotors
    Magnetic bearings
    Lasers
    Air
    Stators
    Stiffness
    Brushless DC motors
    Thrust bearings
    Contacts (fluid mechanics)
    Permanent magnets
    Magnets
    Mirrors

    ASJC Scopus subject areas

    • Engineering(all)
    • Computer Science(all)

    Cite this

    Kawamoto, H. (2000). Transient Vibration of a Laser Scanner Motor in Digital Electrophotography. In Society for Imaging Science and Technology: Image Processing, Image Quality, Image Capture, Systems Conference (pp. 17-21)

    Transient Vibration of a Laser Scanner Motor in Digital Electrophotography. / Kawamoto, Hiroyuki.

    Society for Imaging Science and Technology: Image Processing, Image Quality, Image Capture, Systems Conference. 2000. p. 17-21.

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Kawamoto, H 2000, Transient Vibration of a Laser Scanner Motor in Digital Electrophotography. in Society for Imaging Science and Technology: Image Processing, Image Quality, Image Capture, Systems Conference. pp. 17-21, Final Program and Proceedings: IS and T's Annual Conference, Portland, OR, 00/3/26.
    Kawamoto H. Transient Vibration of a Laser Scanner Motor in Digital Electrophotography. In Society for Imaging Science and Technology: Image Processing, Image Quality, Image Capture, Systems Conference. 2000. p. 17-21
    Kawamoto, Hiroyuki. / Transient Vibration of a Laser Scanner Motor in Digital Electrophotography. Society for Imaging Science and Technology: Image Processing, Image Quality, Image Capture, Systems Conference. 2000. pp. 17-21
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    title = "Transient Vibration of a Laser Scanner Motor in Digital Electrophotography",
    abstract = "This paper describes a transient vibration during start-stop operation of a polygonal mirror scanner motor in a laser printer. Two types of abnormal vibration take place in the rotor driven by a flat-type brushless DC motor and supported by a passive thrust magnetic bearing and a radial air bearing. One is an axial displacement and vibration and another is a radial dry-contact at very low speed region. From results of theoretical and experimental investigations, the following characteristics and countermeasures have been deduced: (1) Repulsive magnetic force induced between the stator coils and rotor magnet of the motor causes the axial static displacement and the axial transient vibration. Soft start-stop scheme of the motor current is effective to reduce the axial vibration. (2) The rotor is statically unstable in the radial direction at very low speed region. This instability occurs because the stiffness of the air bearing is not induced without rotation and it is small at the very low speed region, whereas the magnetic negative stiffness of the magnetic bearing is existent even at a zero speed. Dry contact between the rotor and the stator shaft at the air bearing is induced at the speed lower than a threshold. Since the dry contact reduces the lifetime of the air bearing, it is preferable to avoid frequent start-stop operations and to keep the rotor speed higher than the threshold. The instability is reduced to adopt the magnetic bearing composed of a pair of permanent magnets.",
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    N2 - This paper describes a transient vibration during start-stop operation of a polygonal mirror scanner motor in a laser printer. Two types of abnormal vibration take place in the rotor driven by a flat-type brushless DC motor and supported by a passive thrust magnetic bearing and a radial air bearing. One is an axial displacement and vibration and another is a radial dry-contact at very low speed region. From results of theoretical and experimental investigations, the following characteristics and countermeasures have been deduced: (1) Repulsive magnetic force induced between the stator coils and rotor magnet of the motor causes the axial static displacement and the axial transient vibration. Soft start-stop scheme of the motor current is effective to reduce the axial vibration. (2) The rotor is statically unstable in the radial direction at very low speed region. This instability occurs because the stiffness of the air bearing is not induced without rotation and it is small at the very low speed region, whereas the magnetic negative stiffness of the magnetic bearing is existent even at a zero speed. Dry contact between the rotor and the stator shaft at the air bearing is induced at the speed lower than a threshold. Since the dry contact reduces the lifetime of the air bearing, it is preferable to avoid frequent start-stop operations and to keep the rotor speed higher than the threshold. The instability is reduced to adopt the magnetic bearing composed of a pair of permanent magnets.

    AB - This paper describes a transient vibration during start-stop operation of a polygonal mirror scanner motor in a laser printer. Two types of abnormal vibration take place in the rotor driven by a flat-type brushless DC motor and supported by a passive thrust magnetic bearing and a radial air bearing. One is an axial displacement and vibration and another is a radial dry-contact at very low speed region. From results of theoretical and experimental investigations, the following characteristics and countermeasures have been deduced: (1) Repulsive magnetic force induced between the stator coils and rotor magnet of the motor causes the axial static displacement and the axial transient vibration. Soft start-stop scheme of the motor current is effective to reduce the axial vibration. (2) The rotor is statically unstable in the radial direction at very low speed region. This instability occurs because the stiffness of the air bearing is not induced without rotation and it is small at the very low speed region, whereas the magnetic negative stiffness of the magnetic bearing is existent even at a zero speed. Dry contact between the rotor and the stator shaft at the air bearing is induced at the speed lower than a threshold. Since the dry contact reduces the lifetime of the air bearing, it is preferable to avoid frequent start-stop operations and to keep the rotor speed higher than the threshold. The instability is reduced to adopt the magnetic bearing composed of a pair of permanent magnets.

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