# US 2017/0257570 A1 · Image pickup apparatus including infrared light reduction section, method of controlling the same, and storage medium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0257570 A1 - Document ID: US20170257570A1 - Status: Published application - Kind: A1 - Application number: 15/599,496 - Filed: 2017-05-19 - Published: 2017-09-07 - Earliest claimed: 2014-10-29 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Ryo Kawasaki - Web page: https://patentgrep.com/patent/US20170257570A1 ## CPC - H04N 23/667: Camera operation mode switching, e.g. between still and video, sport and normal or high- and low-resolution modes - H04N 23/60: Control of cameras or camera modules - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An image pickup apparatus capable of accurately inserting/removing an infrared light reduction section. An infrared cut filter is inserted between a photographic optical system and an image pickup device to reduce infrared light contained in an optical image. If an object luminance acquired based on an optical image is lower than a first threshold, a camera control circuit calculates a second threshold for comparison with the object luminance and a third threshold value for comparison with an object luminance detected by a luminance sensor, based on the object luminances and the first threshold, and one of the second and third thresholds is made equal to or higher than the other. The infrared cut filter is selectively inserted or removed based on the object luminances, the second and third switching threshold values. ## Claims ### Claim at position 1 1-21. (canceled) ### Claim 22 An image pickup apparatus including an image pickup device that has an optical image formed thereon through a photographic optical system, and outputs an image signal corresponding to the optical image, comprising: an infrared light reduction unit configured to be inserted into an optical path between the photographic optical system and the image pickup device so as to reduce an amount of infrared light contained in the optical image reaching the image pickup device; a detection unit configured to detect a luminance of an object according to the image signal to thereby obtain a luminance detection result; an illuminating unit configured to illuminate the object with infrared light; a correction unit configured to correct a threshold value for use in determining insertion or removal of said infrared light reduction unit into or from the optical path, based on a light emission intensity of infrared light emitted by said illuminating unit; and a control unit configured to compare the luminance detection result and a corrected threshold value, and determine insertion of said infrared light reduction unit into the optical path according to the comparison result. ### Claim 23 (depends on 22) The image pickup apparatus according to claim 22, wherein said correction unit corrects the threshold value such that the threshold value is made higher as the light emission intensity is higher. ### Claim 24 (depends on 22) The image pickup apparatus according to claim 22, wherein said correction unit corrects the detection result obtained from said detection unit in a state where said infrared light reduction unit is removed from the optical path between the photographic optical system and the image pickup device instead of correcting the threshold value, and wherein said control unit compares the corrected detection result and the threshold value, and determines insertion of said infrared light reduction unit into the optical path according to the comparison result. ### Claim 25 (depends on 24) The image pickup apparatus according to claim 24, wherein said correction unit corrects the detection result such that the detection result is made lower as the light emission intensity is higher. ### Claim 26 (depends on 22) The image pickup apparatus according to claim 22, wherein said correction unit calculates a correction value for correction, based on a rate of change of the light emission intensity and an amount of increase in the detection result. ### Claim 27 (depends on 22) The image pickup apparatus according to claim 22, wherein said correction unit calculates a correction value for correction, using a correction data table in which the correction value for correction is defined according to a relationship between the detection result and the light emission intensity. ### Claim 28 (depends on 22) The image pickup apparatus according to claim 22, wherein said correction unit performs the correction by taking into account at least one of a distance from the image pickup apparatus to an object, temperature of said illuminating unit, and aging of said illuminating unit. ### Claim 29 (depends on 22) The image pickup apparatus according to claim 22, wherein said control unit switches the photographing mode to the color photographing mode in a case where said infrared light reduction unit is inserted into the optical path, and switches the photographing mode to the monochrome photographing mode in a case where said infrared light reduction unit is removed from the optical path. ### Claim 30 (depends on 29) The image pickup apparatus according to claim 29, wherein in a case where the detection result is lower than the threshold value, said control unit changes the photographing mode from the color photographing mode to the monochrome photographing mode. ### Claim 31 (depends on 29) The image pickup apparatus according to claim 29, wherein said control unit caused said illuminating unit to perform illumination when in the monochrome photographing mode. ### Claim 32 (depends on 29) The image pickup apparatus according to claim 29, wherein in a case where the detection result is higher than the corrected threshold value, said control unit causes said illuminating unit to stop illumination, and switches the photographing mode from the monochrome photographing mode to the color photographing mode. ### Claim at position 13 33-34. (canceled) ### Claim 35 A method of controlling an image pickup apparatus including an image pickup device that has an optical image formed thereon through a photographic optical system, and outputs an image signal corresponding to the optical image, an infrared light reduction unit configured to be inserted into an optical path between the photographic optical system and the image pickup device so as to reduce an amount of infrared light contained in the optical image reaching the image pickup device, and an illuminating unit configured to illuminate the object with infrared light, the method comprising: detecting a luminance of an object according to the image signal to thereby obtain a luminance detection result; correcting a threshold value for use in determining insertion or removal of the infrared light reduction unit into or from the optical path, based on a light emission intensity of infrared light emitted by the illuminating unit; and comparing the detection result and a corrected threshold value, and determining insertion of the infrared light reduction unit into the optical path according to the comparison result. ### Claim at position 15 36-37. (canceled) ### Claim 38 A non-transitory computer-readable storage medium storing a computer-executable control program for causing a computer to execute a method of controlling an image pickup apparatus including an image pickup device that has an optical image formed thereon through a photographic optical system, and outputs an image signal corresponding to the optical image, an infrared light reduction unit configured to be inserted into an optical path between the photographic optical system and the image pickup device so as to reduce an amount of infrared light contained in the optical image reaching the image pickup device, and an illuminating unit configured to illuminate the object with infrared light, wherein the method comprises: detecting a luminance of an object according to the image signal to thereby obtain a luminance detection result; correcting a threshold value for use in determining insertion or removal of the infrared light reduction unit into or from the optical path, based on a light emission intensity of infrared light emitted by the illuminating unit; and comparing the detection result and a corrected threshold value, and determining insertion of the infrared light reduction unit into the optical path according to the comparison result.