Abstract: A vibration type motor device for applies a driving signal to a piezoelectric element to obtain a driving force.When the driving signal is applied to the piezoelectric element via a transformer, pulses having different pulse widths can be applied to first and second switching elements, which switch the direction of a current to be supplied to the primary coil of the transformer, and the resolution of the digital driving control is improved.

Abstract: A vibration type actuator apparatus which obtains a driving force by applying an AC signal to an electro-mechanical energy conversion element to generate a vibration force. First and second switching elements are alternately turned on to supply a driving current to the primary coil of a transformer, thereby operating the transformer, and the transformer applies the AC signal to the energy conversion elements. When the two switching elements are simultaneously turned on, the primary coil is short-circuited to immediately consume vibration driving energy when the actuator apparatus is stopped.

Abstract: There is disclosed a control device for selectively driving plural vibration type motors with a single drive circuit. A matching element is provided for matching the characteristics of the drive circuit with those of the selected motor, thus improving the driving efficiency in the drive of different vibration type motors with the same drive circuit.

Abstract: A sheet feeding device includes a vibration member having at least one circular-arc portion, for generating a travelling wave, and a sheet guide for guiding a sheet. Since an amplitude of vibration at an inner circumferential side of the vibration member is smaller than an amplitude of vibration at an outer circumferential side, a distortion is produced in the vibration member in a direction perpendicular to the direction of movement of the sheet. The sheet guide is provided at an inner circumferential side of the vibration member, so that the sheet is fed due to the distortion while being pressed against the sheet guide. Hence, an oblique movement of the sheet due to unevenness in the thickness of the sheet can be prevented.

Abstract: Disclosed is feeding apparatus comprising a first vibration apparatus having projections provided with a predetermined distance therebetween, the first vibration apparatus producing a first travelling vibration wave in response to an electrical signal applied thereto, and a second vibration apparatus having projections located at the positions substantially corresponding to the projections of the first vibration apparatus, the second vibration apparatus producing a second travelling vibration wave proceeding in the same direction as the first travelling vibration wave in response to an electrical signal supplied thereto thereby the sheet inserted between the projections of the first vibration apparatus and the projections of the second vibration apparatus being fed by the first and second travelling vibration waves.

Abstract: This specification discloses a vibration wave driven motor in which frequency signals differing in phase from each other are applied to an electro-mechanical energy conversion element on a vibration member to thereby form a travelling vibration wave and a movable member is driven by the travelling vibration wave. The value of a factor which determines the natural frequency of the resonance system of the motor including a driven member when the driven member is driven by the motor or the frequency of wow-flutter is set so that the frequency of wow-flutter may not coincide with the natural frequency, thereby minimizing the unnecessary vibration of the driven member.

Abstract: An actuator device has a plurality of projections formed in a vibrator, with the projections being in pressure contact with a friction surface of a contact member, and relative movement between the vibrator and the projections is performed by generating vibrations in the vibrator. The actuator device prevents the contact member and the projections from stopping at identical positions in pressure contact with one another at every stop operation of driving by the actuator device to produce projection marks on the friction member, causing wow/flutter and decreasing torque performance.

Abstract: An improved sheet feeding device of this invention includes a variable pressure applying unit for changing a contact pressure between a sheet and vibration members.

Abstract: There is disclosed a sheet feeding device having at least two vibration members pinching a sheet, which is frictionally driven by the travelling vibration waves generated in the vibration members. The device is further provided with a detector for detecting the state of vibration of the vibration members and generating a signal corresponding to the phase difference between the vibrations. The signal is used for correcting the vibration state of the vibrations members, thus significantly reducing the unevenness in the sheet feeding.

Abstract: There is disclosed a sheet feeding device having a vibration member for generating vibration for feeding a sheet member. The vibration member is in frictional engagement with the sheet member, which is fed by vibration generated in the vibration member. The device further has a member for controlling the amplitude of the vibration of the vibration member according to the feeding speed of the sheet member whereby the sheet can be fed with a desired speed.

Abstract: A unit for attenuating frequency components generated in a sideband of a frequency of an AC voltage applied to an electro-mechanical energy conversion element. This attenuation is achieved by modulation performed in a speed control apparatus for a vibration driven motor. The control apparatus includes a filter for cutting frequency components of a smaller frequency difference (fd) or more of an absolute value of a frequency difference between a natural frequency of an n-th order vibration and a natural frequency of an (n-1)th- or (n+1)th-order. A filter output is input to a modulator in a driving circuit, and noise of the vibration driven motor can be greatly reduced.

Abstract: At least two vibration detection electro-mechanical energy conversion element areas substantially centered on the antinodes of both the standing waves are arranged between the group of driving electro-mechanical energy conversion element areas. Amplitudes of two standing waves generated upon application of AC voltages to these groups and a time-phase difference between the standing waves can be accurately detected. The amplitudes of the standing waves can be made equal to each other, and the time-phase difference can be set to be .pi./2, thereby obtaining an ideal vibration state of a travelling vibration wave generated in a vibration plate.