초록 ▼

A camera system having a power zoom lens and an automatic focusing device, comprising a zoom motor for zooming the power zoom lens, a focal length detecting device for detecting a focal length of the power zoom lens, an object distance detecting device for detecting a distance of an object which is

A camera system having a power zoom lens and an automatic focusing device, comprising a zoom motor for zooming the power zoom lens, a focal length detecting device for detecting a focal length of the power zoom lens, an object distance detecting device for detecting a distance of an object which is in focus, and a calculation device for calculating an image magnification in accordance with the focal length and the object distance detected by the focal length detecting device and the object distance detecting device, respectively, and then calculating a target focal length at which the image magnification is kept constant, in accordance with the object distance detected by the object distance detecting device.

대표청구항 ▼

A constant image magnification ratio zooming control apparatus of a zoom lens, comprising: means for detecting a focal length of said zoom lens; means for detecting an amount by which a focus lens of said zoom lens advances from a predetermined position; means for selecting a constant image magnific

A constant image magnification ratio zooming control apparatus of a zoom lens, comprising: means for detecting a focal length of said zoom lens; means for detecting an amount by which a focus lens of said zoom lens advances from a predetermined position; means for selecting a constant image magnification mode from among a plurality of photographing modes, said constant image magnification mode being selected by a predetermined manipulation of a magnification setting switch that is settable by a photographer; means for storing focal length information detected by said focal length detecting means and an advancement amount of said focus lens that is detected by said focus lens advancement amount detecting means when said magnification setting switch is set and when said constant image magnification mode is selected; means for determining a target focal length when said constant image magnification mode is set, according to the following formula: f=x0ㆍf0/x; and means for driving said zoom lens to said target focal length when said constant image magnification mode is set, wherein f equals the target focal length, x0 equals the advancement amount of said focus lens detected by said focus lens advancement amount detecting means and stored in said storing means, f0 equals the focal length information detected by said focal length detecting means and stored in said storing means, and x equals a lens advancement amount for an object to be photographed in an in-focus condition.