초록 ▼

In an interchangeable lens assembly video camera system including an interchangeable lens assembly and a camera, a filter of an AF signal processing circuit (113) of the camera extracts a focus evaluation value signal from an image sensing signal corresponding to one or a plurality of focus detectio

In an interchangeable lens assembly video camera system including an interchangeable lens assembly and a camera, a filter of an AF signal processing circuit (113) of the camera extracts a focus evaluation value signal from an image sensing signal corresponding to one or a plurality of focus detection areas in an image sensing surface, and on the basis of the transmitted focus evaluation value signal from the camera and data stored in a ROM (120), the microcomputer ( 116) performs a zooming operation of a zoom lens (102) while maintaining an in-focus state of a focus lens (105).

대표청구항 ▼

What is claimed is: 1. An interchangeable lens assembly video camera system comprising a camera and an interchangeable lens assembly, wherein said camera comprises extracting means for extracting a predetermined image signal component varying depending on a focus state from an image sensing signal

What is claimed is: 1. An interchangeable lens assembly video camera system comprising a camera and an interchangeable lens assembly, wherein said camera comprises extracting means for extracting a predetermined image signal component varying depending on a focus state from an image sensing signal corresponding to one or a plurality of focus detection areas defined on an image sensing plane of said camera, an operation member for manipulating a zooming operation, and transmitting means for transmitting the predetermined image signal component and a state of said operation member to said lens assembly; said lens assembly comprises receiving means for receiving the predetermined image signal component and the state of said operation member from said camera, a zoom lens for performing a zooming operation; a focus lens for maintaining an in-focus state during the zooming operation, memory means for storing data representing a positional relationship between said zoom lens and said focus lens, zoom lens driving means for driving said zoom lens in accordance with the state of said operation member, control means for judging an in-focus state on the basis of the predetermined image signal component and determining a driving direction and a driving velocity of said focus lens while compensating for a movement of a focal plane caused by the zooming operation of said zoom lens on the basis of the data, and focus lens driving means for driving said focus lens in accordance with the driving direction and the driving velocity; and said lens assembly controls operations of said focus lens and said zoom lens. 2. The system according to claim 1, wherein said extracting means comprises a plurality of filter means for extracting a signal of a predetermined frequency component as a focus evaluating signal from the image sensing signal. 3. The system according to claim 2, wherein said extracting means further comprises peak value detecting means for detecting a peak value of a luminance component in the image sensing signal. 4. The system according to claim 2, wherein said extracting means further comprises contrast component detecting means for detecting a contrast component in the image sensing signal. 5. The system according to claim 4, wherein said extracting means further comprises peak holding means for detecting the contrast component by holding a peak value of a difference between a maximum value and a minimum value of the luminance component. 6. A lens assembly which can be detachably attached to a camera including focus detecting means, comprising: receiving means for receiving a predetermined image signal component extracted from an image signal and varying dependent on a focus state and a state of an operation member for manipulating a zooming operation, both of which are transmitted from said camera; a zoom lens for performing a zooming operation; a focus lens for maintaining an in-focus state during the zooming operation; memory means for storing data representing a positional relationship between said zoom lens and said focus lens; zoom lens driving means for driving said zoom lens in accordance with the state of said operation member; control means for judging the in-focus state on the basis of the predetermined image signal component and determining a driving direction and a driving velocity of said focus lens while compensating for a movement of a focal plane caused by the zooming operation of said zoom lens on the basis of the data; and focus lens driving means for driving said focus lens in accordance with the driving direction and the driving velocity. 7. A camera to which a lens assembly can be detachably attached, comprising: extracting means for extracting a predetermined image signal component varying depending on a focus state from an image sensing signal corresponding to one or a plurality of focus detection areas defined on an image sensing plane of said camera; an operation member for manipulating a zooming operation of a zoom lens of said lens assembly; and transmitting means for transmitting the predetermined image signal component and a state of said operation member to said lens assembly. 8. The camera according to claim 7, wherein said extracting means comprises a plurality of filter means for extracting a signal of a predetermined frequency component as a focus evaluating signal from the image sensing signal. 9. The camera according to claim 8, wherein said extracting means further comprises peak value detecting means for detecting a peak value of a luminance component in the image sensing signal. 10. The camera according to clam 8, wherein said extracting means further comprising contrast component detecting means for detecting a contrast component in the image sensing signal. 11. The camera according to claim 10, wherein said extracting means further comprises peak holding means for detecting the contrast component by holding a peak value of a difference between a maximum value and a minimum value of the luminance component.