IMAGE STABILIZER, AND IMAGE SHAKE CORRECTION METHOD FOR IMAGING DEVICE
An image stabilizer includes an imaging device including an object coverage area changing device for changing an object coverage area, and an image sensor; an image shake correction device which moves a shake correction optical element of the imaging optical system in a plane orthogonal to an optical axis in accordance with a direction and magnitude of vibration applied to the image sensor; a memory, in which area data is prestored, the area data designating changes in relative sizes between an image circle of the imaging optical system and an effective picture area of an imaging surface of the image sensor; and a moving range controller which changes a moving range of the shake correction optical element that corresponds to a change of the object coverage area in accordance with an operating state of the object coverage area changing device based on the area data.
1 . An image stabilizer comprising;
an imaging device including an object coverage area changing device for changing an object coverage area for an object which is to be photographed through an imaging optical system;
an image shake correction device which moves a shake correction optical element of said imaging optical system in a plane orthogonal to an optical axis in accordance with a direction and magnitude of vibration applied to said imaging device;
a memory, in which area data is prestored, said area data designating changes in relative sizes between an image circle of said imaging optical system and an effective picture area of an imaging surface of said imaging device when said object coverage area changing device changes said object coverage area; and
a moving range controller which changes a moving range of said shake correction optical element that corresponds to a change of said object coverage area in accordance with an operating state of said object coverage area changing device based on said area data prestored in said memory.
2 . The image stabilizer according to claim 1 , wherein said moving range controller changes said moving range of said shake correction optical element within a range so that no part of said effective picture area deviates outside from said image circle.
3 . The image stabilizer according to claim 1 , wherein said object coverage area changing device comprises an optical zoom device which changes distances in said optical axis direction between optical elements of said imaging optical system that are positioned on said optical axis to vary an optical focal length.
4 . The image stabilizer according to claim 3 , wherein said moving range controller operates so as to increase said moving range of said shake correction optical element as said optical focal length of said optical zoom device increases.
5 . The image stabilizer according to claim 1 i wherein said imaging optical system comprises an image sensor which produces an electronic image of said object, and
wherein said object coverage area changing device trims a part of said electronic image to change said effective picture area.
6 . The image stabilizer according to claim 5 , wherein said moving range controller operates so as to increase said moving range of said shake correction optical element as an area of a remaining part of said electronic image, that remains after said trimming, decreases.
7 . The image stabilizer according to claim 1 , wherein said imaging optical system comprises an image sensor which produces an electronic image of said object,
wherein said object coverage area changing device comprises:
an optical zoom device which changes distances in said optical axis direction between optical elements of said imaging optical system that are positioned on said optical axis to vary an optical focal length; and
an electronic zoom device which trims a part of an image formed on said image sensor to change said effective picture area.
8 . The image stabilizer according to claim 1 , wherein said shake correction optical element comprises an image sensor.
9 . The image stabilizer according to claim 1 , wherein said imaging optical system comprises a zoom lens system and an image sensor.
10 . An image stabilizer comprising;
an imaging optical system including an image sensor and an optical zoom device for changing a focal length;
an image shake correction device which moves a shake correction optical element of said imaging optical system in a plane orthogonal to an optical axis in accordance with a direction and magnitude of vibration applied to said imaging optical system;
a memory in which area data is prestored, said area data designating changes in size of an image circle of said imaging optical system when said optical zoom device changes said focal length; and
a moving range controller which changes a moving range of said shake correction optical element that corresponds to a change of said object coverage area in accordance with an operating state of said optical zoom device based on said area data prestored in said memory.
11 . The image stabilizer according to claim 10 , wherein said moving range controller changes said moving range of said shake correction optical element within a range so that no part of an effective picture area of an imaging surface of said image sensor deviates outside from said image circle.
12 . An image stabilizer comprising:
an imaging optical system including an image sensor;
an electronic zoom device which trims a part of an image formed on said image sensor to change an object coverage area for an object which is formed through said imaging optical system;
an image shake correction device which moves a shake correction optical element of said imaging optical system in a plane orthogonal to an optical axis in accordance with a direction and magnitude of vibration applied to said imaging optical system;
a memory in which area data is prestored, said area data indicating changes in size of an effective picture area of an imaging surface of said image sensor that corresponds to said object coverage area when said electronic zoom device changes said object coverage area; and
a moving range controller which changes a moving range of said shake correction optical element that corresponds to a change of said effective picture area in accordance with an operating state of said electronic zoom device based on said area data prestored in said memory.
13 . The image stabilizer according to claim 12 , wherein said moving range controller changes said moving range of said shake correction optical element within a range so that no part of said effective picture area deviates outside from said image circle.
14 . A method of correcting image shake in an imaging device,
wherein said imaging device includes an object coverage area changing device for changing an object coverage area for an object which is to be photographed through an imaging optical system, and an image shake correction device which moves a shake correction optical element of said imaging optical system in a plane orthogonal to an optical axis, said method comprising:
prestoring area data in a memory, said area data designating changes in relative sizes between an image circle of said imaging optical system and an effective AD picture area of an imaging surface when said object coverage area changing device changes said object coverage area;
reading said area data from said memory in accordance with an operating state of said object coverage area changing device to calculate a moving range of said shake correction optical element that corresponds to a change of said object coverage area based on said area data read out from said memory; and
moving said shake correction optical element in said plane within said calculated moving range thereof in accordance with a direction and magnitude of vibration applied to said imaging optical system.
15 . The image shake correction method according to claim 14 , wherein said moving range of said shake correction optical element, which is calculated based on said area data read out from said memory, is determined within a range so that no part of said effective picture area deviates outside from said image circle.