# US 10,873,692 B2 · Image pickup apparatus with an optical filter used for in-focus determinations > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,873,692 B2 - Document ID: US10873692B2 - Status: Granted - Kind: B2 - Application number: 15/861,770 - Filed: 2018-01-04 - Published: 2018-07-12 - Granted: 2020-12-22 - Earliest claimed: 2017-01-10 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Harukazu Watanabe - Web page: https://patentgrep.com/patent/US10873692B2 ## CPC - H04N 23/672: {based on the phase difference signals} - G03B 3/10: Power-operated focusing - G03B 13/36: Autofocus systems - H04N 23/55: Optical parts specially adapted for electronic image sensors; Mounting thereof - H04N 23/62: Control of parameters via user interfaces - H04N 23/84: for processing colour signals - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - 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 An image pickup apparatus includes an image pickup element, an optical filter, a filter driver configured to insert and to eject the optical filter into and from an optical path between the optical system and the image sensor, and a controller configured to search for an in-focus position based on the image pickup signal and to control a position of the focus lens based on a result of a search. The controller determines whether the focus lens is to move by a first amount after the optical filter moves from one of the position on the optical path and the position outside the optical path to the other, and before the search starts, based on a difference between an in-focus position when the optical filter is disposed on the optical path and an in-focus position when the optical filter is not disposed on the optical path. ## Claims ### Claim 1 An image pickup apparatus comprising: an image sensor configured to photoelectrically convert an object image formed by an optical system including a focus lens, and to generate an image pickup signal; an optical filter; an actuator configured to insert and to eject the optical filter into and from an optical path between the optical system and the image sensor; and at least one processor or circuit programmed to function as a controller configured to search for an in-focus position based on the image pickup signal and to control a position of the focus lens based on a result of a search, wherein the controller determines whether the focus lens is to move by a first amount after the optical filter moves from one of the position on the optical path and the position outside the optical path to the other, and before the search starts, based on a difference between an in-focus position when the optical filter is disposed on the optical path and an in-focus position when the optical filter is not disposed on the optical path, and wherein the controller searches for the in-focus position after moving the focus lens by the first amount when the difference is larger than a threshold, and searches for the in-focus position from a position of the focus lens before the optical filter is moved when the difference is smaller than the threshold. ### Claim 2 (depends on 1) The image pickup apparatus according to claim 1, wherein the controller estimates the difference based on the image pickup signal. ### Claim 3 (depends on 1) The image pickup apparatus according to claim 1, wherein the optical filter removes at least one of an infrared light component and an ultraviolet light component. ### Claim 4 (depends on 1) The image pickup apparatus according to claim 1, wherein the image pickup signal is a RGB signal, and wherein the controller estimates the difference based on a difference amount between a value representing a luminance of an R signal in the RGB signal when the optical filter is inserted into the optical path and a value representing a luminance of the R signal in the RGB signal when the optical filter is disposed on the position outside the optical path. ### Claim 5 (depends on 4) The image pickup apparatus according to claim 4, wherein the value representing the luminance of the R signal is an average value of luminance values of the R signal. ### Claim 6 (depends on 1) The image pickup apparatus according to claim 1, wherein the image pickup signal is a RGB signal, and wherein the controller estimates the difference based on a difference amount between a value representing a luminance of an B signal in the RGB signal when the optical filter is inserted into the optical path and a value representing a luminance of the B signal in the RGB signal when the optical filter is disposed on the position outside the optical path. ### Claim 7 (depends on 6) The image pickup apparatus according to claim 6, wherein the value representing the luminance of the B signal is an average value of a luminance value of the B signal. ### Claim 8 (depends on 1) The image pickup apparatus according to claim 1, wherein the first amount is a predetermined amount. ### Claim 9 (depends on 1) The image pickup apparatus according to claim 1, wherein the controller determines whether the focus lens is to move by the first amount before the search is performed, based on at least one of a current F-number, a current focal length, and aberration information of the optical system. ### Claim 10 (depends on 1) The image pickup apparatus according to claim 1, wherein the controller searches for the in-focus position by obtaining information on a contrast of the image pickup signal while scanning a focus position every second amount smaller than the first amount. ### Claim 11 An image pickup apparatus comprising: an image sensor configured to photoelectrically convert an object image formed by an optical system including a focus lens, and to generate an image pickup signal; an optical filter; an actuator configured to insert and to eject the optical filter into and from an optical path between the optical system and the image sensor; and at least one processor or circuit programmed to function as a controller configured to search for an in-focus position based on the image pickup signal and to control a position of the focus lens based on a result of a search, wherein the controller determines whether the focus lens is to move by a first amount after the optical filter moves from one of the position on the optical path and the position outside the optical path to the other, and before the search starts, based on an estimation result of a type of a light source for illuminating an object, and wherein the controller searches for the in-focus position from a position of the focus lens before the optical filter is moved when a ratio of a component cut by the optical filter included in components of light illuminated from the light source is large. ### Claim 12 (depends on 11) The image pickup apparatus according to claim 11, wherein the controller searches for the in-focus position after moving the focus lens by the first amount when the difference is larger than a threshold, and searches for the in-focus position from a position of the focus lens before the optical filter is moved when the difference is smaller than the threshold. ### Claim 13 (depends on 11) The image pickup apparatus according to claim 11, wherein the optical filter removes at least one of an infrared light component and an ultraviolet light component. ### Claim 14 (depends on 11) The image pickup apparatus according to claim 11, wherein the first amount is a predetermined amount. ### Claim 15 (depends on 11) The image pickup apparatus according to claim 11, wherein the controller searches for the in-focus position by obtaining information on a contrast of the image pickup signal while scanning a focus position every second amount smaller than the first amount.