In recent years, there are more and more chances to capture a still image by using a small-sized camera for a mobile phone. Accordingly, even though image defocusing (i.e., vibration) occurs when capturing a still image, various optical image stabilizers or optical image stabilization (hereinafter, referred to as “OIS”) capable of capturing clear still images and preventing the image from defocusing on an image forming surface have been proposed. As such an OIS method, an optical method such as a sensor shift method or a lens shift method, and a software method of performing OIS by image processing by using software are known.
In the sensor shift method, an imaging element (i.e., CCD or CMOS sensor) is movably configured centering around a reference position by using an actuator. Further, in the lens shift method, a correction lens is configured to move for adjustment on a plane orthogonal to an optical axis. Further, in the software method, for example, a noise component is removed from a detection result of detection means, and specific information necessary for correction of image defocusing due to a hand shaking an imaging device from a detection signal in which the noise component is removed is calculated, so that a captured image is stationary in a state where the imaging device is stationary without the image defocusing. Further, there is also a proposal for an optical image stabilizer that corrects image defocusing by oscillating a lens module (or a camera module) that holds a lens and an imaging element.
For example, PTL 1 discloses an optical image stabilizer capable of correcting image defocusing generated when a still image is captured by a small-sized camera for a mobile phone in order to obtain an image without image defocusing, in which the optical image stabilizer is provided in an AF camera drive unit, and a permanent magnet is commonly used to reduce the number of components. As a result, the size (mainly, height) of the optical image stabilizer is made small (i.e., reduced). Further, in PTL 1, four hall elements that correspond to position detection means for detecting the position of the autofocus lens drive unit are arranged along respective sides of the lens module.