# US 10,120,172 B2 · Optical system and image pickup apparatus including the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,120,172 B2 - Document ID: US10120172B2 - Status: Granted - Kind: B2 - Application number: 15/595,231 - Filed: 2017-05-15 - Published: 2017-11-23 - Granted: 2018-11-06 - Earliest claimed: 2016-05-19 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Yuichi Gyoda - Web page: https://patentgrep.com/patent/US10120172B2 ## CPC - G02B 15/28: arranged +-+ - G02B 7/09: adapted for automatic focusing or varying magnification - G02B 9/62: having six components only - G02B 27/0025: {for optical correction, e.g. distorsion, aberration} - G02B 27/646: {compensating for small deviations, e.g. due to vibration or shake (movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68)} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract Provided is an optical system, comprising, in order from an object side: a positive first unit; a negative second unit; and a positive third unit, in which, during focusing from infinity to a close distance, the second unit moves toward the image side, and an interval between adjacent units is changed, in which the first unit consists of, in order from the object side: a negative first sub-unit, which does not move for image stabilization; a positive second sub-unit, which moves during the image stabilization; and a third sub-unit, which does not moves for the image stabilization, and in which a distance from a lens surface closest to the object side in the first unit to an image plane when focusing at infinity, and a distance from a lens surface closest to the object side in the second sub-unit to the image plane when focusing at infinity are appropriately set. ## Claims ### Claim 1 An optical system, comprising, in order from an object side to an image side: a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; and a third lens unit having a positive refractive power, wherein, during focusing from infinity to a close distance, the second lens unit moves toward the image side, and an interval between each pair of adjacent lens units is changed, wherein the first lens unit consists of, in order from the object side to the image side: a first lens sub-unit having a negative refractive power which does not move for image stabilization; a second lens sub-unit having a positive refractive power, which moves during the image stabilization; and a third lens sub-unit which does not move for the image stabilization, wherein the second lens sub-unit includes a meniscus positive lens LIS having a concave surface facing the object side, and wherein the following conditional expression is satisfied: 0.782.0, where β2 represents a lateral magnification of the second lens unit when focusing at infinity, and β3 represents a lateral magnification of the third lens unit when focusing at infinity. ### Claim 7 (depends on 1) An optical system according to claim 1, wherein the second lens sub-unit consists of the meniscus positive lens LIS having a concave surface facing the object side. ### Claim 8 (depends on 1) An optical system according to claim 1, wherein the following conditional expression is satisfied: Nd_LIS>1.70, where Nd_LIS represents a refractive index of a material of the meniscus positive lens LIS. ### Claim 9 (depends on 1) An optical system according to claim 1, wherein the following conditional expression is satisfied: −β>0.49, where β represents a lateral magnification of the optical system when focusing at a minimum object distance. ### Claim 10 (depends on 1) An optical system according to claim 1, wherein the first lens unit does not move for focusing. ### Claim 11 (depends on 1) An optical system according to claim 1, wherein the third lens unit does not move for focusing. ### Claim 12 (depends on 1) An optical system according to claim 1, wherein the second lens unit consists of a cemented lens formed by cementing a positive lens and a negative lens. ### Claim 13 (depends on 1) An optical system according to claim 1, further comprising an aperture stop, which is arranged between the first lens unit and the second lens unit. ### Claim 14 (depends on 1) An optical system according to claim 1, further comprising a flare cut stop having one of constant and variable aperture diameter, which is arranged between the second lens unit and the third lens unit. ### Claim 15 An image pickup apparatus, comprising: an optical system; and an image pickup element configured to receive an image formed by the optical system, the optical system comprising, in order from an object side to an image side: a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; and a third lens unit having a positive refractive power, wherein, during focusing from infinity to a close distance, the second lens unit moves toward the image side, and an interval between each pair of adjacent lens units is changed, wherein the first lens unit consists of, in order from the object side to the image side: a first lens sub-unit having a negative refractive power, which does not move for image stabilization; a second lens sub-unit having a positive refractive power, which moves during the image stabilization; and a third lens sub-unit, which does not move for the image stabilization, wherein the second lens sub-unit includes a meniscus positive lens LIS having a concave surface facing the object side, and wherein the following conditional expression is satisfied: 0.78