Focal point position correction apparatus
AssigneeNikon Corporation
InventorMotoyuki Ohtake
Life of this patent
Estimating the term…
Abstract
A focal point position correction apparatus for a camera with a zoom lens system, has an adjustment amount calculation device for calculating an adjustment amount .delta.h of at least one lens unit Gh in the zoom lens system using a formula based on focal length information that defines a change amount corresponding to the focal length of the entire lens system and correction coefficients pre-stored for back focus adjustment, and a lens unit driver for moving the lens unit Gh by the adjustment amount .delta.h along the optical axis in the respective focal length states so as to correct any deviation, of the focal point position with respect to the film surface of a best image surface, caused by manufacturing errors, over the entire zooming range.
Claims12
A focal point position correction apparatus for a camera with a zoom lens system, comprising:
- adjustment amount calculation means for calculating an adjustment amount .delta.h of at least one lens unit Gh in the zoom lens system using a formula based on focal length information that defines a change amount corresponding to a focal length of the entire lens system and correction coefficients pre-stored for correcting a deviation of a focal point position with respect to a film surface of a best image surface, caused by manufacturing errors;
- and
- driving means for moving the lens unit Gh in accordance with the adjustment amount .delta.h along an optical axis in respective focal length states so as to correct the deviation over an entire zooming range.
Dependencies are inferred from the claim text.