# US 2014/0192220 A1 · Image pickup apparatus and control method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192220 A1 - Document ID: US20140192220A1 - Status: Published application - Kind: A1 - Application number: 14/232,419 - Filed: 2012-07-24 - Published: 2014-07-10 - Earliest claimed: 2011-07-25 - Assignees: Canon Kabushiki Kaisha - Inventors: Masafumi Kimura; Koichi Fukuda - Web page: https://patentgrep.com/patent/US20140192220A1 ## CPC - H04N 23/673: {based on contrast or high frequency components of image signals, e.g. hill climbing method} - G02B 7/285: {including two or more different focus detection devices, e.g. both an active and a passive focus detecting device} - G02B 7/34: using different areas in a pupil plane - 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)} - G03B 13/36: Autofocus systems - H04N 23/672: {based on the phase difference signals} - 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 An image pickup apparatus for simultaneously realizing a phase difference AF and a contrast AF decides a shift amount of an image signal corresponding to a focus evaluation position every exit pupil area, generates an image corresponding to an image plane position by executing an arithmetic operation processing based on the decided shift amount to the image signal, calculates an evaluation value of a contrast of the generated image, and calculates an evaluation value of a correlation between the images corresponding to the different exit pupil areas in the generated image. ## Claims ### Claim 1 An image pickup apparatus including an image pickup element for photoelectrically converting an optical image of an object which enters through a photographing lens and outputting an image signal, comprising: a pupil division unit configured to pupil-divide light from the photographing lens on a micro lens basis; a sensor having an output unit configured to output signals corresponding to charges divided by the pupil division unit; an image generation unit configured to generate an image corresponding to each of the image plane positions by changing outputs of the sensor to be subjected to synthesization on the basis of shift amounts of the signals corresponding to a plurality of image plane positions; and a contrast evaluation unit configured to calculate a contrast evaluation value of the image generated by the image generation unit. ### Claim 2 (depends on 1) An image pickup apparatus according to claim 1, wherein the pupil division unit is a micro lens array arranged on a photosensing surface of the image pickup element, the micro lens array being constructed such that a plurality of pixels formed on the photosensing surface of the image pickup element are divided into a plurality of pixel groups correspondingly to each micro lens, and the micro lens allowing each pixel of the corresponding pixel group to correspond to the light from a different exit pupil area of the photographing lens. ### Claim 3 (depends on 1) An image pickup apparatus according to claim 1, further comprising a correlation calculation unit configured to calculate a correlation evaluation value between the images corresponding to the different pupil areas in the generated image. ### Claim 4 (depends on 3) An image pickup apparatus according to claim 3, wherein the correlation calculation unit calculates a difference between image data corresponding to selected different exit pupil areas among the image data of the generated image, thereby calculating a phase difference between the images which pass through the different exit pupil areas. ### Claim 5 (depends on 1) An image pickup apparatus according to claim 1, further comprising an in-focus position decision unit configured to decide an in-focus position of the photographing lens from the contrast evaluation value calculated by the contrast evaluation unit. ### Claim 6 (depends on 4) An image pickup apparatus according to claim 4, further comprising an in-focus position decision unit configured to decide an in-focus position of the photographing lens from the contrast evaluation value calculated by the contrast evaluation unit and the phase difference. ### Claim 7 (depends on 1) An image pickup apparatus according to claim 1, further comprising a storage unit configured to store the image generated by the image generation unit and display unit for displaying the image stored in the storage unit. ### Claim 8 An image pickup apparatus including an image pickup element for photoelectrically converting an optical image of an object which enters through a photographing lens and outputting an image signal, comprising: a pupil division unit configured to pupil-divide light from the photographing lens on a micro lens basis; a sensor having an output unit configured to output signals corresponding to charges divided by the pupil division unit; a detection unit for detecting a phase difference between images which pass through different pupil areas from a correlation between the images corresponding to different pupil areas obtained from the signal from the sensor; an image generation unit configured to generate an image corresponding to each of the image plane positions by changing outputs of the sensor to be subjected to synthesization on the basis of shift amounts of the signals corresponding to a plurality of image plane positions; and a contrast evaluation unit configured to calculate a contrast evaluation value of the image generated by the image generation unit on the basis of a detection result of the phase difference. ### Claim 9 (depends on 8) An image pickup apparatus according to claim 8, wherein the pupil division unit is a micro lens array arranged on a photosensing surface of the image pickup element, the micro lens array being constructed such that a plurality of pixels formed on the photosensing surface of the image pickup element are divided into a plurality of pixel groups correspondingly to each micro lens, and the micro lens allowing each pixel of the corresponding pixel group to correspond to the light from a different exit pupil area of the photographing lens. ### Claim 10 A control method of an image pickup apparatus including an image pickup element for photoelectrically converting an optical image of an object which enters through a photographing lens and outputting an image signal, comprising: a pupil division step of pupil-dividing light from the photographing lens on a micro lens basis; an output step of obtaining signals corresponding to charges divided by the pupil division step from a sensor; an image generation step of generating an image corresponding to each of the image plane positions by changing outputs of the sensor to be subjected to synthesization on the basis of shift amounts of the signals corresponding to a plurality of image plane positions; and a contrast evaluation step of calculating a contrast evaluation value of the image generated by the image generation step. ### Claim 11 A control method of an image pickup apparatus including an image pickup element for photoelectrically converting an optical image of an object which enters through a photographing lens and outputting an image signal, comprising: a pupil division step of pupil-dividing light from the photographing lens on a micro lens basis; an output step of obtaining signals corresponding to charges divided by the pupil division step from a sensor; a detection step of detecting a phase difference between images which pass through different pupil areas from a correlation between the images corresponding to different pupil areas obtained from the signal from the sensor; an image generation step of generating an image corresponding to each of the image plane positions by changing outputs of the sensor to be subjected to synthesization on the basis of shift amounts of the signals corresponding to a plurality of image plane positions; and a contrast evaluation step of calculating a contrast evaluation value of the image generated by the image generation step on the basis of a detection result of the phase difference. ### Claim 12 (depends on 10) A non-transitory computer-readable storage medium storing a program comprising a program code for causing a computer to execute a control method of the image pickup apparatus according to claim 10. ### Claim 13 (depends on 11) A non-transitory computer-readable storage medium storing a program comprising a program code for causing a computer to execute a control method of the image pickup apparatus according to claim 11.