Fuji Photo Optical Co., Ltd.

Kenichi Takahashi

Kouichi Nagata

Toshihisa Ishijima

In an image stabilizing apparatus in which an actuator for a pivoting gimbal suspension is controlled by a feedback loop, the gain of feedback loop based on the angular position is enhanced when the angular velocity is at a first set value or higher until the angular velocity becomes a second set value or lower, whereby a panning mode is automatically attained when a pan/tilt operation is carried out. Also the gain of feedback loop based on the angular position is enhanced when the angular velocity is enhanced until a lapse of a predetermined time after starting the pivoting control of the gimbal suspension, whereby the behavior of gimbal suspension is stabilized.

Image stabilizing apparatus

In an image stabilizing apparatus in which an actuator for pivoting a gimbal suspension is driven under PWM control by way of a driving circuit, the pulse width of waveform outputted from a CPU to the driving circuit is enhanced when the power voltage V in the driving circuit drops. The CPU reads out the power voltage V and enhances the pulse width of output waveform from W to W as the power voltage V decreases from its rated voltage V to a lower voltage V . The correction rate (W /W ) is set to the reciprocal (V /V ) of the drop rate of power voltage V , so as to yield an appropriate actuator driving power in response to the drop in power voltage V .

In an image stabilizing apparatus in which inner and outer gimbals are pivoted about two pivotal axes so as to fix an erect prism with respect to an inertial system, a torsion coil spring is disposed to provide one-side stressing between the inner and outer gimbals so as to pivotally stress the inner gimbal with respect to the outer gimbal in one direction. When image stabilizing control is started, the elastic force of the torsion coil spring instantly changes the angular position of the inner gimbal so that a capacitor is charged earlier, thereby enhancing the response in PWM control.

In an image stabilizing apparatus employing a system in which the rotational position of gimbal suspension is controlled on the basis of an output value from an angular velocity sensor attached thereto, an actuator for pivotally moving an inner gimbal suspension member is incorporated in the gimbal suspension means, thereby making the apparatus to fully exhibit its functions and allowing the case of a binocular to which the apparatus is attached to have a compact configuration. A rotating motor (105) for pivotally moving the inner gimbal suspension member (107) comprises a magnet (156) and a coil (154) which are disposed close and opposite to each other. The magnet (156) is firmly supported by the inner gimbal suspension member (107), while the coil (154) is firmly supported by the outer gimbal suspension member (7).

It is judged whether or not the pivotal movement of gimbal suspension is in a locked state. When the gimbal suspension is judged to be in the locked state, an actuator is stopped, and an operator is informed of this state, whereby the actuator can be prevented from being damaged, and the operator can rapidly respond to the locked state. An angular velocity value detected by an angular velocity sensor is read out (S6); an angle value detected by a position sensor is read out (S7); the read-out value of detedted angular velocity is subracted from an amplified value of detected angle (S9); the value resulting from the subtraction is integrated with respect to time (S10); and it is judged whether or not the gimbal suspension is in a locked state (S11). If it is consequently judged that the gimbal suspension is in the locked state, the control system is stopped (S12), and an alarm LED is flickered (S13).

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Omiya, Japan

Kenichi Takahashi