Automatic focusing device
AssigneeCanon Kabushiki Kaisha
InventorHirofumi Suda
Life of this patent
Estimating the term…
Abstract
An automatic focusing device includes a motion vector detecting circuit which detects from a picked-up image signal a movement of a picked-up image within an image plane, a filter which extracts a signal of a predetermined frequency component from the picked-up image signal, a gate circuit which takes out from the signal extracted by the filter a signal corresponding to a focus detecting area in the image plane, an area setting circuit which corrects the position of the focus detecting area by controlling the gate circuit on the basis of a detection output of the motion vector detecting circuit, and a driving part which moves a focusing lens to an in-focus position according to the signal extracted by the gate circuit.
Claims15
An automatic focusing device comprising:
- image storing means for storing an image signal outputted from image pickup means;
- motion vector detecting means for detecting from image signals a movement of an image and outputting a motion vector;
- extracting means for extracting a predetermined frequency component signal from the image signals in a focus detecting area as a focus evaluating signal;
- and
- control means for controlling said extracting means and said image storing means to simultaneously and synchronously shift a read-out region for reading out the image signal from said image storing means and the focus detecting area different from the readout region in response to a common motion vector detected by said motion vector detecting means.
An automatic focusing device comprising:
- storing means for storing an image signal outputted from image pickup means;
- motion vector detecting means for detecting from the image signal a movement of an image and outputting a motion vector corresponding to the movement;
- image cutting-out means for electronically shifting a range of cutting out the image signal stored in the storing means on the basis of a detection output of said motion vector detecting means in such a way as to cancel the movement of the image and stabilize the image of an object formed on an image sensing plane;
- filter means for extracting a signal of a predetermined frequency component from an output signal read out from said storing means by said image cutting-out means and had been corrected the movement of the image;
- gate means for taking out from the signal extracted by said filter means a signal corresponding to a focus detecting area different from the range of said motion vector detecting means and shifted on the basis of the detection output of said motion vector detecting means;
- and
- driving means for driving a focusing lens to move to an in-focus position on the basis of an output of said gate means.
A video camera comprising:
- a) image pickup means arranged to output a picked-up image signal;
- b) memory means for storing the image signal;
- c) area setting means for setting a focus detecting area in an image plane;
- d) motion detecting means for detecting an image shake by detecting movement of an image on said image plane;
- and
- e) control means for controlling said memory means and said area setting means to simultaneously and synchronously shift said focus detecting area and a read-out area different from the focus detecting area for reading out the image signal from said memory means on the basis of a common output of said motion detecting means.
Dependencies are inferred from the claim text.