# US 10,484,592 B2 · Focus adjustment device, focus adjustment method, and non-transitory storage medium for storing focus adjustment programs for performing focus adjustment in response to image signals of an image pickup device including focus detection pixels > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,484,592 B2 - Document ID: US10484592B2 - Status: Granted - Kind: B2 - Application number: 15/821,674 - Filed: 2017-11-22 - Published: 2018-05-31 - Granted: 2019-11-19 - Earliest claimed: 2016-11-29 - Assignees: Olympus Corporation - Applicants: Olympus Corporation - Inventors: Tomohiro Hoshino; Tetsuo Kikuchi - Web page: https://patentgrep.com/patent/US10484592B2 ## CPC - H04N 23/672: {based on the phase difference signals} - H04N 23/632: {for displaying or modifying preview images prior to image capturing, e.g. variety of image resolutions or capturing parameters} - H04N 23/73: by influencing the exposure time - H04N 23/76: by influencing the image signals - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A focus detection section performs focus detection based on image signals of focus detection pixels of an image pickup device, included in the image signals acquired based on an exposure value for a live view display, calculates a gain correction value to correct the image signals of the focus detection pixels based on a result of the focus detection, and corrects image signals of focus detection pixels to be acquired by a next image pickup operation with the gain correction value to perform the focus detection. A control section causes the image pickup device to perform an AF image pickup operation using exposure value corrected based on the gain correction value, as an exposure value for the AF image pickup operation. The focus detection section performs focus detection based on the image signals of the focus detection pixels in accordance with the AF image pickup operation. ## Claims ### Claim 1 A focus adjustment device which performs focus adjustment in response to image signals of an image pickup device including focus detection pixels, the device comprising: a display configured to provide live view display based on the image signals of the image pickup device; a switch configured to provide instruction to start focus adjustment; and a processor configured to: control an image pickup operation of the image pickup device based on an exposure value for the live view display to the display based on the image signals of the image pickup device to acquire the image signals; perform focus detection based on image signals of the focus detection pixels, included in the image signals of the image pickup device; calculate a gain correction value to correct the image signals of the focus detection pixels based on a result of the focus detection; correct image signals of focus detection pixels to be acquired by a next image pickup operation with the gain correction value to perform the focus detection; perform focus adjustment based on the image signals of the focus detection pixels in accordance with the instruction of the switch; correct the exposure value based on the gain correction value when the focus adjustment is performed based on the image signals of the focus detection pixels in accordance with the instruction to start the focus adjustment; cause the image pickup device to perform an AF image pickup operation using the corrected exposure value as an exposure value for the AF image pickup operation; and perform focus detection based on the image signals of the focus detection pixels in accordance with the AF image pickup operation. ### Claim 2 (depends on 1) The device according to claim 1, wherein the processor is further configured to: determine whether the image signals of the focus detection pixels are saturated or not; and calculate the gain correction value when the processor determines that the image signals of the focus detection pixels are saturated before the instruction. ### Claim 3 (depends on 1) The device according to claim 1, wherein the processor is further configured to: make a focus detection calculation based on the image signals of the focus detection pixels to calculate reliability; and calculate the gain correction value when the reliability calculated by the processor is low before the instruction section provides the instruction. ### Claim 4 (depends on 1) The device according to claim 1, wherein the processor is further configured to: set a plurality of focus detection areas in an image pickup area of the image pickup device; determine whether the image signals of the focus detection pixels are saturated for each of the focus detection areas; make a focus detection calculation based on the image signals of the focus detection pixels for each of the focus detection areas to calculate reliability; and calculate the gain correction value when there is no focus detection area in which the processor determines that the image signals of the focus detection pixels are not saturated before the instruction, and that the reliability exceeds a predetermined threshold value. ### Claim 5 (depends on 4) The device according to claim 4, wherein when the processor determines that a plurality of reliabilities acquired for a same focus detection area at different times fall within a predetermined permissible range before the instruction section provides the instruction, and corrects the gain correction value using a latest gain correction value calculated for the focus detection area as a basis. ### Claim 6 (depends on 5) The device according to claim 5, wherein the processor corrects the gain correction value such that the image signals of the focus detection pixels become smaller for the focus detection area in which the processor determines that the image signals are saturated, before the instruction. ### Claim 7 (depends on 5) The device according to claim 5, wherein the processor corrects the gain correction value such that the image signals of the focus detection pixels become larger for the focus detection area in which the processor determines that the image signals are not saturated, before the instruction. ### Claim 8 (depends on 7) The device according to claim 7, wherein the processor determines a correction amount of the gain correction value based on a ratio of the reliability to the threshold value. ### Claim 9 (depends on 1) The device according to claim 1, wherein the processor is further configured to: generate a first photometric value by photometry for the live view display and generates a second photometric value by photometry for focus adjustment, based on the image signals of the image pickup device; and correct the gain correction value based on the first photometric value and the second photometric value and calculates the exposure value for the AF image pickup operation based on the corrected gain correction value. ### Claim 10 A focus adjustment method for performing focus adjustment by image signals of an image pickup device including focus detection pixels, the method comprising: controlling an image pickup operation of the image pickup device based on an exposure value for providing live view display to a display section based on the image signals of the image pickup device to acquire the image signals; performing focus detection based on image signals of the focus detection pixels, included in the image signals of the image pickup device, calculating a gain correction value to correct the image signals of the focus detection pixels based on a result of the focus detection, and performing focus detection by correcting image signals of focus detection pixels acquired in a next image pickup operation, with the gain correction value; providing instruction to start the focus adjustment; correcting the exposure value based on the gain correction value when the focus adjustment is performed based on the image signals of the focus detection pixels in accordance with the instruction to start the focus adjustment, and causing the image pickup device to perform an AF image pickup operation using the corrected exposure value as an exposure value for the AF image pickup operation; and performing focus detection based on the image signals of the focus detection pixels by the AF image pickup operation. ### Claim 11 (depends on 10) The method according to claim 10, further comprising: determining whether the image signals of the focus detection pixels are saturated or not, wherein the calculating the gain correction value includes calculating the gain correction value in case of determining that the image signals of the focus detection pixels are saturated before the instruction. ### Claim 12 (depends on 10) The method according to claim 10, further comprising: making a focus detection calculation based on the image signals of the focus detection pixels to calculate reliability, wherein the calculating the gain correction value includes calculating the gain correction value when calculated reliability is low before the instruction. ### Claim 13 (depends on 10) The method according to claim 10, further comprising: setting a plurality of focus detection areas in an image pickup area of the image pickup device; determining whether the image signals of the focus detection pixels are saturated for each of the focus detection areas; and making a focus detection calculation based on the image signals of the focus detection pixels for each of the focus detection areas to calculate reliability, wherein the calculating the gain correction value includes calculating the gain correction value when there is no focus detection area in which is determined that the image signals of the focus detection pixels are not saturated before the instruction, and that the reliability exceeds a predetermined threshold value. ### Claim 14 (depends on 13) The method according to claim 13, wherein in case of determining that a plurality of reliabilities acquired for a same focus detection area at different times fall within a predetermined permissible range before the instruction, the calculating the gain correction value includes correcting the gain correction value using a latest gain correction value calculated for the focus detection area as a basis. ### Claim 15 (depends on 14) The method according to claim 14, wherein the calculating the gain correction value includes correcting the gain correction value such that the image signals of the focus detection pixels become smaller for the focus detection area in which is determined that the image signals are saturated, before the instruction. ### Claim 16 (depends on 14) The method according to claim 14, wherein the calculating the gain correction value includes correcting the gain correction value such that the image signals of the focus detection pixels become larger for the focus detection area in which is determined that the image signals are not saturated, before the instruction. ### Claim 17 (depends on 16) The method according to claim 16, wherein the calculating the gain correction value includes determining a correction amount of the gain correction value based on a ratio of the reliability to the threshold value. ### Claim 18 (depends on 10) The method according to claim 10, further comprising: generating a first photometric value by photometry for the live view display and generating a second photometric value by photometry for focus adjustment, based on the image signals of the image pickup device; and correcting the gain correction value based on the first photometric value and the second photometric value and calculating the exposure value for the AF image pickup operation based on the corrected gain correction value. ### Claim 19 A non-transitory storage medium for storing computer-readable focus adjustment programs which are executed by a computer which performs focus adjustment by image signals of an image pickup device including focus detection pixels, when the focus adjust programs are executed by the computer, the focus adjust programs causing the computer to: control an image pickup operation of the image pickup device based on an exposure value for providing live view display to a display section based on the image signals of the image pickup device to acquire the image signals; perform focus detection based on image signals of the focus detection pixels, included in the image signals of the image pickup device, calculate a gain correction value to correct the image signals of the focus detection pixels based on a result of the focus detection, and perform focus detection by correcting image signals of focus detection pixels acquired in a next image pickup operation, with the gain correction value; provide instruction to start the focus adjustment; correct the exposure value based on the gain correction value when the focus adjustment is performed based on the image signals of the focus detection pixels in accordance with the instruction to start the focus adjustment, and cause the image pickup device to perform an AF image pickup operation using the corrected exposure value as an exposure value for the AF image pickup operation; and perform focus detection based on the image signals of the focus detection pixels by the AF image pickup operation. ### Claim 20 (depends on 19) The medium according to claim 19, wherein when the focus adjust programs are executed by the computer, the focus adjust programs further causes the computer to determine whether the image signals of the focus detection pixels are saturated or not, and the causing the computer to calculate the gain correction value includes causing the computer to calculate the gain correction value when the computer determines that the image signals of the focus detection pixels are saturated before the instruction. ### Claim 21 (depends on 19) The medium according to claim 19, wherein when the focus adjust programs are executed by the computer, the focus adjust programs further causes the computer to make a focus detection calculation based on the image signals of the focus detection pixels to calculate reliability, and the causing the computer to calculate the gain correction value includes causing the computer to calculate the gain correction value when the reliability calculated by the computer is low before the instruction. ### Claim 22 (depends on 19) The medium according to claim 19, wherein when the focus adjust programs are executed by the computer, the focus adjust programs further causes the computer to set a plurality of focus detection areas in an image pickup area of the image pickup device; determine whether the image signals of the focus detection pixels are saturated for each of the focus detection areas; and make a focus detection calculation based on the image signals of the focus detection pixels for each of the focus detection areas to calculate reliability, and the causing the computer to calculate the gain correction value includes causing the computer to calculate the gain correction value when there is no focus detection area in which the computer determine that the image signals of the focus detection pixels are not saturated before the instruction, and that the reliability exceeds a predetermined threshold value.