Abstract A camera zoom lens automatic magnification apparatus for automatically changing the focal length of a zoom lens wherein distances to at least three points on a subject--at the center, to the left and to the right--in the angle of view are measured by a range finding device and a zoom lens driving device for changing the focal length of the zoom lens is controlled by a control device according to the output of the range finding device. The control device consists of a first decision device to decide which point is the nearest by comparing the distances to each point measured by the range finding device, a second decision device which, based on the lens focal length corresponding to the closest distance as found by the first decision device and on the depth of field for that focal length, checks if there is any other point's distance that is within the depth of field for that focal length, a third decision device which determines the zoom ratio according to a predetermined program using the result of the second decision device, and an output device which drives the zoom lens driving device according to the third decision device.
Inventors
👤 Takamichi Takehana
👤 Osamu Murayama
👤 Hideaki Nakajima
👤 Masatoshi Yamada
👤 Makoto Hamada
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-29 19:34
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/282
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
207 words
A camera zoom lens automatic magnification apparatus for automatically changing the focal length of a zoom lens according to a subject to be photographed comprising a zoom lens driving device for changing the focal length of the zoom lens; a range finding device which measures distances to at least three points on the subject--at the center, to the left and to the right--in the angle of view; and a control device which controls the zoom lens driving device according to the output of the range finding device, the control device consisting of a first decision means to decide which point is the nearest by comparing the distances to each point measured by the range finding device, a second decision means which, based on the lens focal length corresponding to the closest distance as found by the first decision means and on the depth of field for that focal length, checks if there is any other point's distance that is within the depth of field for that focal length, a third decision means which determines the zoom ratio according to a predetermined program using the result of tee second decision means, and an output means which drives the zoom lens driving device according to the third decision means.
Claim 2
Dependent Claim
207 words
A camera zoom lens automatic magnification apparatus for automatically changing the focal length of a zoom lens according to a subject to be photographed comprising a zoom lens driving device for changing the focal length of the zoom lens; a range finding device which measures distances to at least three points on the subject--at the center, to the left and to the right--in the angle of view; and a control device which controls the zoom lens driving device according to the output of the range finding device, the control device consisting of a first decision means to decide which point is the nearest by comparing the distances to each point measured by the range finding device, a second decision means which, based on the lens focal length corresponding to the closest distance as found by the first decision means and on the depth of field for that focal length, checks if there is any other point's distance that is within the depth of field for that focal length, a third decision means which determines the zoom ratio according to a predetermined program using the result of tee second decision means, and an output means which drives the zoom lens driving device according to the third decision means.
Claim 3
Dependent Claim
52 words
The camera zoom lens automatic magnification apparatus according to claim 1, wherein said zoom ratio decision means has a function of increasing the zoom ratio toward the telephoto side when the central point's distance falls within the depth of field for the focal length of the lens corresponding to the closest distance.