Lens barrel

Claim 2

A lens barrel mountable on a camera body, comprising: a phototaking lens system; absolute position detection means for detecting the absolute position of a focusing lens group of said phototaking lens system in the axial direction; phototaking distance data memory means storing phototaking distance data corresponding to the absolute position of said focusing lens group of said phototaking lens system; aberration data memory means storing data of aberration between a predetermined image plane and the actual image plane of said phototaking lens system; calculation means for calculating corrected phototaking distance data corresponding to an absolute position to which said focusing lens group is set when focused on an object, by correcting the corresponding phototaking distance data based on said aberration data; and means for transferring the corrected phototaking distance data to said camera body.

Claim 3

A lens barrel according to claim 1, wherein said aberration data indicates the aberration between the image plane of said phototaking lens system after FFD adjustment and the predetermined image plane.

Claim 4

A lens barrel according to claim 1, wherein said aberration is a measured value after FFD adjustment, and said aberration data memory means is a writable memory.

Claim 5

A lens barrel according to claim 1, wherein said aberration data indicates the aberration between the image plane of said phototaking lens system and the predetermined image plane as a function of temperature.

Claim 6

A lens barrel according to claim 1, wherein said aberration data indicates the aberration between the image plane of said phototaking lens system and the predetermined image plane, resulting from a variation in the focal distance.

Claim 7

A lens barrel according to claim 1, wherein said aberration data indicates the aberration between the image plane of said phototaking lens system and the predetermined image plane, resulting from a variation in the aberrations caused by a change in the phototaking distance.

Claim 8

A lens barrel according to claim 1, wherein said absolute position detection means is an encoder.

Claim 9

A lens barrel according to claim 1, wherein said predetermined image plane is an image plane determined at the designing of said phototaking lens system.

Claim 10

A lens barrel mountable on a camera body, comprising: a phototaking lens system; absolute position detection means for detecting the absolute position of a focusing lens group of said phototaking lens system in the axial direction; phototaking distance data memory means storing phototaking distance data corresponding to the absolute position of said focusing lens group of said phototaking lens system; image plane movement amount data memory means storing data of movement amount of the image plane, from an image plane for an infinite object distance, corresponding to the absolute position of said focusing lens group of said phototaking lens system; aberration data memory means storing data of aberration between a predetermined image plane and the actual image plane of said phototaking lens system; calculation means for calculating corrected phototaking distance data corresponding to an absolute position to which said focusing lens group is set when focused on an object, by corrrecting the corresponding phototaking distance data based on said movement amount data and said aberration data; and means for transferring the corrected phototaking distance data to said camera body.

Claim 11

A lens barrel mountable on a camera body, comprising: a phototaking lens system; absolute position detection means for detecting the absolute position of a focusing lens group of said phototaking lens system in the axial direction; phototaking distance data memory means storing phototaking distance data corresponding to the absolute position of said focusing lens group of said phototaking lens system; image plane movement amount data memory means storing data of movement amount of the image plane, from an image plane for an infinite object distance, corresponding to the absolute position of said focusing lens group of said phototaking lens system; aberration data memory means storing data of aberration between a predetermined image plane and the actual image plane of said phototaking lens system; calculation means for calculating corrected phototaking distance data corresponding to an absolute position to which said focusing lens group is set when focused on an object, by corrrecting the corresponding phototaking distance data based on said movement amount data and said aberration data; and means for transferring the corrected phototaking distance data to said camera body.

Claim 12

A lens barrel according to claim 9, wherein said aberration data indicates the aberration between the image plane of said phototaking lens system after FFD adjustment and the predetermined image plane.

Claim 13

A lens barrel according to claim 9, wherein said aberration data indicates the aberration between the image plane of said phototaking lens system and the predetermined image plane as a function of temperature.

Claim 14

A lens barrel according to claim 9, wherein said aberration is a measured value after FFD adjustment, and said aberration data memory means is a writable memory.

Claim 15

A lens barrel according to claim 9, wherein said aberration data indicates the aberration between the image plane of said phototaking lens system and the predetermined image plane, resulting from a variation in the focal distance.

Claim 16

A lens barrel according to claim 9, wherein said aberration data indicates the aberration between the image plane of said phototaking lens system and the predetermined image plane, resulting from a variation in the aberrations caused by a change in the phototaking distance.

Claim 17

A lens barrel according to claim 9, wherein said absolute position detection means is an encoder.

Claim 18

A lens barrel according to claim 9, wherein said predetermined image plane is an image plane determined at the designing of said phototaking lens system.

Claim 19

A lens barrel mountable on a camera body, comprising: a focusing lens group; a distance encoder for detecting the absolute position of said focusing lens group in the axial direction; memory means storing phototaking distance data corresponding to a set phototaking distance indicated by an output of said distance encoder when said focusing lens group is at an in-focus position, and phototaking distance error data representing an error between (a) actual phototaking distance corresponding to said in-focus position of said focusing lens group and (b) said set phototaking distance; and an output device for sending said phototaking distance data and said phototaking distance error data to said camera body.

Claim 20

A lens barrel mountable on a camera body, comprising: a focusing lens group; a distance encoder for detecting the absolute position of said focusing lens group in the axial direction; memory means storing phototaking distance data corresponding to a set phototaking distance indicated by an output of said distance encoder when said focusing lens group is at an in-focus position, and phototaking distance error data representing an error between (a) actual phototaking distance corresponding to said in-focus position of said focusing lens group and (b) said set phototaking distance; and an output device for sending said phototaking distance data and said phototaking distance error data to said camera body.

Claim 21

A lens barrel according to claim 17, wherein said phototaking distance error data indicates a value corresponding to a possible range of error between actual phototaking distance and said set phototaking distance.

Claim 22

A camera system comprising a lens barrel according to claim 17 and a camera body, wherein said camera body includes a signal processing device for receiving said phototaking distance data and said phototaking distance error data from said lens barrel, and varying processing of said phototaking distance data based on said phototaking distance error data.

Claim 23

A camera system comprising a lens barrel according to claim 17 and a camera body, wherein said camera body includes a signal processing device for receiving said phototaking distance data and said phototaking distance error data from said lens barrel, and varying the processing of said phototaking distance data based on said phototaking distance error data.

Claim 24

A lens barrel according to claim 17, wherein: said phototaking distance data is determined by a first equation composed of a term including logarithm of said set phototaking distance, and a constant term; and said phototaking distance error data is determined by a second equation including logarithm of a ratio of actual phototaking distance to said set phototaking distance.

Claim 25

A lens barrel according to claim 21, wherein said first equation is given as: Xi=A+(B×2/log 2)×log (Ri) in which: Xi: phototaking distance data; Ri: set phototaking distance; A, B: constants, and said second equation is given as: E[±]=(C×2/log 2)×log (R[e±]/Ri) in which: R[e±]: actual phototaking distance; E[±]: error data; C: constant.

Claim 26

A lens barrel mountable on a camera body, comprising: a phototaking lens system; a distance encoder for detecting the absolute position of a lens of said phototaking lens system in the axial direction; memory means storing phototaking distance data corresponding to a set phototaking distance indicated by the output of said distance encoder, focal distance data representing the focal distance of said phototaking lens system, and magnification correction data; and an output device for outputting said phototaking distance data, said focal distance data and said magnification correction data; wherein said magnification correction data indicates a correction coefficient for determining a set phototaking magnification from said focal distance data and said phototaking distance data, and said magnification correction data is not varied with the phototaking distance.

Claim 27

A lens barrel mountable on a camera body, comprising: a phototaking lens system; a distance encoder for detecting the absolute position of a lens of said phototaking lens system in the axial direction; memory means storing phototaking distance data corresponding to a set phototaking distance indicated by the output of said distance encoder, focal distance data representing the focal distance of said phototaking lens system, and magnification correction data; and an output device for outputting said phototaking distance data, said focal distance data and said magnification correction data; wherein said magnification correction data indicates a correction coefficient for determining a set phototaking magnification from said focal distance data and said phototaking distance data, and said magnification correction data is not varied with the phototaking distance.

Claim 28

A camera system comprising a lens barrel according to claim 23 and a camera body, wherein said camera body includes a signal processing device for receiving said phototaking distance data, said focal distance data and said magnification correction data from the output device of said lens barrel and determining the set phototaking magnification from said received data.

Claim 29

A lens barrel according to claim 23, wherein the set phototaking magnification is given by: Mi'=(f/Ri)/[1-(f/Ri)×D] wherein: Mi': set phototaking magnification; Ri: set phototaking distance represented by said phototaking distance data; f: focal distance represented by said focal distance data; D: magnification correction data.

Claim 30

A lens barrel mountable on a camera body, comprising: a focusing lens group; a distance encoder for detecting the absolute position of said focusing lens group in an optical axis direction; memory means for storing phototaking distance data corresponding to the output of said distance encoder, and phototaking distance error data corresponding to an error between (a) the phototaking distance data and (b) actual phototaking distance corresponding to the detected position of said focusing lens group; and an output device for outputting said phototaking distance data and said phototaking distance error data to said camera body.

Claim 31

A lens barrel mountable on a camera body, comprising: a focusing lens group; a distance encoder for detecting the absolute position of said focusing lens group in an optical axis direction; memory means for storing phototaking distance data corresponding to the output of said distance encoder, and phototaking distance error data corresponding to an error between (a) the phototaking distance data and (b) actual phototaking distance corresponding to the detected position of said focusing lens group; and an output device for outputting said phototaking distance data and said phototaking distance error data to said camera body.

Claim 32

A lens barrel mountable on a camera body, comprising: a phototaking lens system; a distance encoder for detecting the absolute position of a focusing lens group in said phototaking lens system in an optical axis direction; memory means for storing phototaking distance data corresponding to a set phototaking distance indicated by the output of said distance encoder, focal distance data representing the focal distance of said phototaking lens system, and phototaking magnification correction data representing a correction coefficient corresponding to the focal distance data and independent of phototaking distance; and an output device for outputting said phototaking distance data, said focal distance data and said phototaking magnification correction data to said camera body.

Claim 33

A lens barrel mountable on a camera body, comprising: a phototaking lens system; a distance encoder for detecting the absolute position of a focusing lens group in said phototaking lens system in an optical axis direction; memory means for storing phototaking distance data corresponding to a set phototaking distance indicated by the output of said distance encoder, focal distance data representing the focal distance of said phototaking lens system, and phototaking magnification correction data representing a correction coefficient corresponding to the focal distance data and independent of phototaking distance; and an output device for outputting said phototaking distance data, said focal distance data and said phototaking magnification correction data to said camera body.

Claim 34

A camera system comprising a lens barrel according to claim 27, and a camera body, wherein said camera body includes a signal processing device for receiving said phototaking distance data, said focal distance data and said phototaking magnification correction data from said lens barrel, and determining a set phototaking magnification based on said received data.