# US 2021/0243355 A1 · Lens barrel, camera system, and imaging device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0243355 A1 - Document ID: US20210243355A1 - Status: Published application - Kind: A1 - Application number: 17/227,709 - Filed: 2021-04-12 - Published: 2021-08-05 - Earliest claimed: 2013-05-10 - Assignees: Nikon Corporation - Applicants: Nikon Corporation - Inventors: Hiroyuki TOMITA - Web page: https://patentgrep.com/patent/US20210243355A1 ## CPC - H04N 23/663: for controlling interchangeable camera parts based on electronic image sensor signals - G02B 7/08: adapted to co-operate with a remote control mechanism - G02B 7/36: using image sharpness techniques {, e.g. image processing techniques for generating autofocus signals (image data processing per se G06T; in cameras having a solid state image sensor H04N23/67)} - G02B 7/38: measured at different points on the optical axis {, e.g. focussing on two or more planes and comparing image data} - G03B 13/36: Autofocus systems - G03B 17/14: interchangeably - H04N 23/67: Focus control based on electronic image sensor signals - H04N 23/69: Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming - G03B 19/12: Reflex cameras with single objective and a movable reflector or a partly-transmitting mirror - G03B 2206/00: Systems for exchange of information between different pieces of apparatus, e.g. for exchanging trimming information, for photo finishing - H04N 23/55: Optical parts specially adapted for electronic image sensors; Mounting thereof - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) ## Abstract A lens barrel of the invention includes: an imaging optical system including a focus adjustment lens; a driver that drives the focus adjustment lens in a direction of an optical axis; a transceiver that transmits and receives a signal to and from a camera body; and a controller that controls the transceiver to repeatedly transmit a first image plane transfer coefficient which is determined in correspondence with a position of the focus adjustment lens included in the imaging optical system and a second image plane transfer coefficient which does not depend on the position of the focus adjustment lens to the camera body at a predetermined interval, and, when the controller repeatedly transmits the second image plane transfer coefficient to the camera body, the controller varies the second image plane transfer coefficient over time. ## Claims ### Claim 1 A camera body comprising: a receiver configured to receive a signal from a lens barrel comprising an imaging optical system comprising a focus adjustment lens; an image sensor configured to capture an image formed by the imaging optical system; and a controller configured to control the receiver to receive a first image plane transfer coefficient and a second image plane transfer coefficient, the first image plane transfer coefficient corresponding to a value of TL/TI and being determined in correspondence with a position of the focus adjustment lens, the second image plane transfer coefficient being less than a minimum value of the first image plane transfer coefficient from the lens barrel, and the TL being an amount of movement of the focus adjustment lens, and the TI being an amount of movement of an image plane of the imaging optical system. ### Claim 2 (depends on 1) The camera body according to claim 1, wherein the controller repeatedly receives the first image plane transfer coefficient and the second image plane transfer coefficient from the lens barrel. ### Claim 3 A camera body comprising: a receiver configured to receive a signal from a lens barrel comprising an imaging optical system comprising a focus adjustment lens; an image sensor configured to capture an image formed by the imaging optical system; and a controller configured to control the receiver to receive a first image plane transfer coefficient and a second image plane transfer coefficient, the first image plane transfer coefficient corresponding to a value of TL/TI and being determined in correspondence with a position of the focus adjustment lens, the second image plane transfer coefficient being greater than a minimum value of the first image plane transfer coefficient from the lens barrel, and the TL being an amount of movement of the focus adjustment lens, and the TI being an amount of movement of an image plane of the imaging optical system. ### Claim 4 (depends on 3) The camera body according to claim 3, wherein the controller repeatedly receives the first image plane transfer coefficient and the second image plane transfer coefficient from the lens barrel. ### Claim 5 A camera body comprising: a receiver configured to receive a signal from a lens barrel comprising an imaging optical system comprising a focus adjustment lens; an image sensor configured to capture an image formed by the imaging optical system; and a controller configured to control the receiver to receive a first image plane transfer coefficient and a second image plane transfer coefficient, the first image plane transfer coefficient corresponding to a value of TI/TL and being determined in correspondence with a position of the focus adjustment lens, the second image plane transfer coefficient being less than a minimum value of the first image plane transfer coefficient from the lens barrel, and the TL being an amount of movement of the focus adjustment lens, and the TI being an amount of movement of an image plane of the imaging optical system. ### Claim 6 (depends on 5) The camera body according to claim 5, wherein the controller repeatedly receives the first image plane transfer coefficient and the second image plane transfer coefficient the lens barrel. ### Claim 7 A camera body comprising: a receiver configured to receive a signal from a lens barrel comprising an imaging optical system comprising a focus adjustment lens; an image sensor configured to capture an image formed by the imaging optical system; and a controller configured to control the receiver to receive a first image plane transfer coefficient and a second image plane transfer coefficient, the first image plane transfer coefficient corresponding to a value of TI/TL and being determined in correspondence with a position of the focus adjustment lens, the second image plane transfer coefficient being greater than a minimum value of the first image plane transfer coefficient from the lens barrel, and the TL being an amount of movement of the focus adjustment lens, and the TI being an amount of movement of an image plane of the imaging optical system. ### Claim 8 (depends on 7) The camera body according to claim 7, wherein the controller repeatedly receives the first image plane transfer coefficient and the second image plane transfer coefficient from the lens barrel.