Control apparatus for vibration wave actuator
AssigneeCanon Kabushiki Kaisha
InventorsKenichi Kataoka, Akio Atsuta, Shinji Yamamoto, Tadashi Hayashi, Jun Ito
Life of this patent
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Abstract
This invention relates to an arrangement for detecting the driven state of a vibration wave actuator apparatus and provides an apparatus in which a waveform signal having an amplitude corresponding to a vibration state is generated by a monitor circuit, and this waveform signal is level-detected by a comparing circuit having a predetermined threshold so as to form a signal having a pulse width corresponding to the amplitude of the waveform signal, thereby detecting a vibration state from the pulse width.
Claims13
A vibration wave actuator apparatus which excites a vibration member and obtains a driving force by applying a frequency signal to a driving electro-mechanical energy conversion element mounted on the vibration member, comprising:
- a driven state detecting unit which detects a vibration state of the vibration member, said driven state detecting unit including a monitor unit which outputs a waveform signal having an amplitude corresponding to the vibration state of the vibration member, a pulse width forming circuit which forms a pulse width signal by comparing a signal from said monitor unit with a threshold, and a determining circuit which determines the driven state in accordance with the pulse width.
A control apparatus for a vibration wave actuator including a driving unit which forms driving vibrations in a vibration member by applying a frequency signal to an electro-mechanical energy conversion element mounted on the vibration member, and a driven state detecting unit which detects a driven state of the vibration member, wherein
- said driven state detecting unit comprises a state detecting unit which detects a driven state of the vibration member and outputs a waveform signal having an amplitude corresponding to the driven state, a comparing circuit which compares an output waveform signal from said state detecting unit with one or a plurality of thresholds and outputs a pulse signal, a pulse width detecting circuit which detects a pulse width or pulse widths of one or a plurality of pulse signals output from said comparing circuit, and a determining circuit which determines the driven state in accordance with one or a plurality of pulse widths detected by said pulse width detecting circuit.
A control apparatus for a vibration wave actuator including a driving unit which forms driving vibrations in a vibration member by applying a frequency signal to an electro-mechanical energy conversion element mounted on the vibration member, and a driven state detecting unit which detects a driven state of the vibration member, wherein
- said driven state detecting unit comprises a state detecting unit which detects a driven state of the vibration member and outputs a waveform signal having an amplitude corresponding to the driven state, a multiplying circuit which multiplies the output waveform signal from said state detecting unit by one or a plurality of coefficients, a comparing circuit which compares one or a plurality of multiplication signals obtained by said multiplying circuit with one or a plurality of thresholds and outputs a pulse signal, a pulse width detecting circuit which detects one or a plurality of pulse signals output from said comparing circuit, and a determining circuit which determines the driven state in accordance with one or a plurality of pulse widths detected by said pulse width detecting circuit.
A control apparatus for a vibration wave actuator including a driving unit which forms driving vibrations in a vibration member by applying a frequency signal to an electro-mechanical energy conversion element mounted on the vibration member, and a driven state detecting unit which detects a voltage applied to the electro-mechanical energy conversion element of the vibration member, wherein
- said driven state detecting unit comprises a comparing circuit which compares the applied voltage with one or a plurality of thresholds and outputs a pulse signal, a pulse width detecting circuit which detects a pulse width one or a plurality of pulse signals output from said comparing circuit, and a control circuit which increases/decreases the applied voltage in accordance with one or a plurality of pulse widths detected by said pulse width detecting circuit.
A control apparatus for a vibration wave actuator including a driving unit which forms driving vibrations in a vibration member by applying a frequency signal to an electro-mechanical energy conversion element mounted on the vibration member, and a driven state detecting unit which detects a voltage applied to the electro-mechanical energy conversion element of the vibration member, wherein
- said driven state detecting unit comprises a multiplying circuit which multiplies the applied voltage by one or a plurality of coefficients, a comparing circuit which compares one or a plurality of multiplication signal obtained by said multiplying means with one or a plurality of thresholds, and outputs a pulse signal, a pulse width detecting circuit which detects a pulse width of one or a plurality of pulse signals output from said comparing circuit, and a control circuit which increases/decreases the applied voltage in accordance with one or a plurality of pulse widths detected by said pulse width detecting circuit.
A control apparatus for a vibration wave actuator including a driving unit which forms driving vibrations in a vibration member by applying a frequency signal to an electro-mechanical energy conversion element mounted on the vibration member, and a driven state detecting unit which detects a voltage applied to the electro-mechanical energy conversion element of the vibration member, wherein
- said driven state detecting unit comprises a state detecting circuit which detects a vibration amplitude of the vibration member or an inflow current to the electro-mechanical energy conversion element and outputs a detection result as a waveform signal, a first comparing circuit which compares the output waveform signal from said state detecting circuit with one or a plurality of thresholds and outputs a first pulse signal, a first pulse width detecting circuit which detects a pulse width of the first pulse signal, a second comparing circuit for comparing the applied voltage with one or a plurality of thresholds and outputs a second pulse signal, a second pulse width detecting circuit which detects a pulse width of the second pulse signal, a phase difference detecting circuit which detects a phase difference between the first pulse signal and the second pulse signal, and a control circuit which, when an output from said first pulse width detecting circuit is larger than a predetermined value, controls the frequency signal in accordance with a phase difference detecting result from said phase difference detecting circuit.
Dependencies are inferred from the claim text.