Image stabilizing apparatus

• US 6,515,799 B2
• Filed: 03/15/2002
• Issued: 02/04/2003
• Est. Priority Date: 09/28/1999
• Status: Expired due to Fees

• Current Assignee: Fuji Photo Optical Co. Ltd (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Optical Co. Ltd (Fujifilm Holdings Corporation)
• Inventors: Takahashi, Kenichi, Nagata, Kouichi, Ishijima, Toshihisa
• Primary Examiner(s): NGUYEN, THONG Q
• Application Number:
  US10/097,599
• Publication Number:
  US 20020093739A1
• Time in Patent Office: 326 Days
• Field of Search: 359/554-557, 359/407-410, 359/399, 396/52-55, 348/208
• US Class Current: 359/557
• CPC Class Codes: G02B 23/18 for binocular arrangements focusing binocular pairs G02B7/06; adjusting pupillary distance of binocular pairs G02B7/12
• CPC Class Codes: G02B 27/646 compensating for small deviations, e.g. due to vibration or shake movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68
• CPC Class Codes: G03B 2205/0023 by tilting or inclining one or more optical elements with respect to the optical axis
• CPC Class Codes: G03B 2217/005 Blur detection
• CPC Class Codes: G03B 5/00 Adjustment of optical system relative to image or object surface other than for focusing
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6812 based on additional sensors, e.g. acceleration sensors
• CPC Class Codes: H04N 23/686 with a variable apex prism
• CPC Class Codes: H04N 23/687 by shifting the lens or sensor position

Abstract

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.

Claims

1. An image stabilizing apparatus mounted in an optical apparatus having a monocular or binocular optical system in which an erect prism is disposed between an objective lens and an eyepiece, whereas said objective lens and eyepiece of said optical system are secured within a case;

said image stabilizing apparatus comprising;

gimbal suspension means, adapted to pivotally attach said erect prism to said case, having two pivotal axes extending sidewise and vertical directions of said optical apparatus, respectively;

an actuator for pivoting said gimbal suspension means about said two pivotal axes;

two angular position detecting means for detecting respective angular positions of said gimbal suspension means about said two pivotal axes;

two angular velocity detecting means, secured to said gimbal suspension means, for detecting respective angular velocities of said gimbal suspension means about said two pivotal axes;

feedback control means for driving said actuator, according to an angular position and angular velocity detected by said angular position detecting means and angular velocity detecting means, so as to fix said erect prism with respect to an inertial system and controlling said pivoting of said gimbal suspension means; and

gain enhancing means for enhancing a gain of a feedback loop based on said angular position until a lapse of a predetermined time after starting said pivoting control of said gimbal suspension means.

2. An image stabilizing apparatus according to claim 1, wherein said gain of feedback loop based on said angular position within said predetermined time is set to such a characteristic that said gain is fixed at a higher value immediately after starting said pivoting control and then gradually decreases.

3. An image stabilizing apparatus according to claim 2, wherein said predetermined time is set to substantially the same value as the time required for an output voltage from said angular velocity detecting means to converge onto a reference voltage V_ref after a power switch is turned ON.