Image stabilization control circuit
View Patent ↗An image stabilization control circuit controls an optical element driving element configured to move an optical element provided in an imaging apparatus based on an output signal of a vibration detection element provided in the imaging apparatus. The image stabilization control circuit includes an analog-digital conversion circuit configured to receive an analog signal from a position detection element that detects the position of the optical element and convert the input analog signal into a digital signal, and a servo circuit configured to generate a correction signal for correcting the position of the optical element based on an output signal of the analog-digital conversion circuit and output the generated correction signal to the optical element driving element. The servo circuit includes a digital filter circuit and a register. The digital filter circuit performs filter processing based on a filter coefficient stored in the register.
1. An image stabilization control circuit, comprising:
a high-pass filter configured to remove a low-frequency component from an output signal of a vibration detection element;
a movement amount calculation circuit configured to calculate a movement amount of an imaging apparatus based on an output signal of the high-pass filter;
a centering processing circuit configured to apply a subtraction process in which a predetermined value is subtracted from an output signal of the movement amount calculation circuit such that an optical element is prevented from approaching a limit point of a movable range and output an obtained value to a servo circuit;
an analog-digital conversion circuit configured to receive an analog signal from a position detection element that detects a position of the optical element and convert the input analog signal into a digital signal; and
the servo circuit configured to generate a correction signal for correcting the position of the optical element based on the output signal of the analog-digital conversion circuit and output a generated correction signal to an optical element driving element,
wherein the servo circuit includes a digital filter circuit and a register, and the digital filter circuit performs filter processing based on a filter coefficient stored in the register, and
the servo circuit generates the correction signal based on a sum of an output signal of the position detection element that detects the position of the optical element and an output signal of the centering processing circuit.
2. The image stabilization control circuit according to claim 1 , further comprising
a pan/tilt determination circuit configured to compare an output signal of the high-pass filter with a predetermined threshold and determine whether a panning operation or a tilting operation is performed based on a result of comparison, and
a gain adjustment circuit configured to adjust a gain of an output signal of the high-pass filter,
wherein the gain adjustment circuit changes the gain according to a determination result obtained by the pan/tilt determination circuit.
3. An imaging apparatus comprising:
a vibration detection element configured to detect vibration of an imaging apparatus;
an optical element;
a position detection element configured to detect a position of the optical element;
an optical element driving element configured to drive the optical element; and
an image stabilization control circuit configured to control the optical element driving element based on an output signal of the vibration detection element,
wherein the image stabilization control circuit comprises:
a high-pass filter configured to remove a low-frequency component from the output signal of the vibration detection element,
a movement amount calculation circuit configured to calculate a movement amount of the imaging apparatus based on an output signal of the high-pass filter; and
a centering processing circuit configured to apply a subtraction process in which a predetermined value is subtracted from an output signal of the movement amount calculation circuit such that the optical element is prevented from approaching a limit point of a movable range and output an obtained value to a servo circuit; and
the servo circuit configured to generate a correction signal for correcting the position of the optical element based on an output signal of the centering processing circuit and output a generated correction signal to the optical element driving element,
wherein the servo circuit includes a digital filter circuit and a register, and the digital filter circuit performs filter processing based on a filter coefficient stored in the register.