# US 10,771,682 B2 · Camera viewfinder > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,771,682 B2 - Document ID: US10771682B2 - Status: Granted - Kind: B2 - Application number: 15/485,912 - Filed: 2017-04-12 - Published: 2017-10-19 - Granted: 2020-09-08 - Earliest claimed: 2016-04-14 - Assignees: Arnold & Richter Cine Technik GmbH & Co. Betriebs KG - Applicants: Arnold & Richter Cine Technik GmbH & Co. Betriebs KG - Inventors: Julius Muschaweck - Web page: https://patentgrep.com/patent/US10771682B2 ## CPC - H04N 23/611: where the recognised objects include parts of the human body - G02B 17/023: {for extending or folding an optical path, e.g. delay lines} - G02B 23/14: Viewfinders (for photographic apparatus G03B13/02) - G02B 26/0825: {the reflecting element being a flexible sheet or membrane, e.g. for varying the focus (flexible mirrors for cosmetic use A45D42/24)} - G02B 26/0875: {by means of one or more refracting elements} - G02B 27/0068: {having means for controlling the degree of correction, e.g. using phase modulators, movable elements (controlling the phase of light using moving or deformable elements G02B26/06)} - G03B 13/06: with lenses with or without reflectors - G06V 40/19: Sensors therefor - G06V 40/193: {Preprocessing; Feature extraction} - G06V 40/197: {Matching; Classification} - H04N 23/50: Constructional details - H04N 23/56: provided with illuminating means - A61B 3/1035: {for measuring astigmatism (testing astigmatism A61B3/036)} - H04N 23/63: by using electronic viewfinders - 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) - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A camera viewfinder comprises an electronic display apparatus that is configured for the display of images that are recorded by an image sensor of an electronic camera. The camera viewfinder further comprises two mirrors for reflecting the images displayed by the display apparatus, of which at least one mirror is a free-form surface mirror whose reflective surface is formed as a free-form surface that does not have any continuous translation symmetry or rotational symmetry. At least one of the free-form surface mirrors is adjustable to at least partially compensate a vision defect of a user. ## Claims ### Claim 1 A camera viewfinder (10) of an electronic camera, comprising an electronic display apparatus (12) that is configured for the display of images that are recorded by an image sensor of the electronic camera; and at least two mirrors (20, 22, 24) for reflecting the images displayed by the display apparatus (12), of which at least one mirror is a free-form surface mirror (20, 22, 24) whose reflective surface is formed as a free-form surface that has no continuous translation symmetry or rotational symmetry and which is not deformable, wherein at least one of the free-form surface mirrors (20, 22, 24) is adjustable during use of the electronic camera to at least partially compensate a vision defect of a user, wherein the at least one free-form surface mirror (20, 22, 24) is adjustable during use of the electronic camera in accordance with at least one of the following: a) the at least one adjustable free-form surface mirror (20, 22, 24) can be tilted about at least one axis; and b) the at least one adjustable free-form surface mirror (20, 22, 24) is movable in a translatory manner in at least one spatial direction so that the at least one free-form surface mirror is movable in a straight line along the at least one spatial direction. ### Claim 2 (depends on 1) A camera viewfinder (10) in accordance with claim 1, wherein the at least one adjustable free-form surface mirror (20, 22, 24) is configured to at least partially compensate a field-constant astigmatism of the user by the tilting about the at least one axis. ### Claim 3 (depends on 1) A camera viewfinder (10) in accordance with claim 1, wherein the at least one adjustable free-form surface mirror (20, 22, 24) is tiltable about at least one axis and is movable in a translatory manner in at least one spatial direction. ### Claim 4 (depends on 1) A camera viewfinder (10) in accordance with claim 1, wherein the at least one adjustable free-form surface mirror (20, 22, 24) is adjustable by at least two different degrees of freedom. ### Claim 5 (depends on 1) A camera viewfinder (10) in accordance with claim 1, wherein the camera viewfinder (10) has at least two adjustable free-form surface mirrors that are adjustable in different degrees of freedom. ### Claim 6 (depends on 1) A camera viewfinder (10) in accordance with claim 1, wherein the free-form surface of the adjustable free-form surface mirror (20, 22, 24) is configured such that an adjustment of this free-form surface mirror (20, 22, 24) generates an astigmatism as at least substantially the only aberration. ### Claim 7 (depends on 1) A camera viewfinder (10) in accordance with claim 1, wherein the at least one adjustable free-form surface mirror (20, 22, 24) is formed from plastic and has a reflective metal coating. ### Claim 8 (depends on 1) A camera viewfinder (10) in accordance with claim 1, wherein a lens arrangement with variable focal length is provided in the optical path of the camera viewfinder (10) for the correction of a refractive vision defect of the user. ### Claim 9 (depends on 8) A camera viewfinder (10) in accordance with claim 8, wherein the lens arrangement comprises a pair of mutually displaceable Alvarez lenses. ### Claim 10 (depends on 8) A camera viewfinder (10) in accordance with claim 8, wherein the lens arrangement comprises at least one lens having a variable radius of curvature. ### Claim 11 (depends on 1) A camera viewfinder (10) in accordance with claim 1, furthermore comprising at least one electrically controllable actuator (30, 32) that is configured to adjust the at least one adjustable free-form surface mirror (20, 22, 24). ### Claim 12 (depends on 1) A camera viewfinder (10) in accordance with claim 1, furthermore comprising a light source; a control and evaluation device (44) that is configured to activate the light source to generate a punctiform light spot on the retina of the eye of the user; and an optoelectronic receiver apparatus (42) connected to the control and evaluation device (44) for receiving light scattered back from the eye, with the control and evaluation device (44) being configured to determine a degree of a vision defect of the user on the basis of the received light. ### Claim 13 (depends on 12) A camera viewfinder (10) in accordance with claim 12, wherein the electronic display apparatus (12) has a two-dimensional matrix of light-emitting display elements; and wherein the light source comprises at least one display element of the display apparatus (12). ### Claim 14 (depends on 12) A camera viewfinder (10) in accordance with claim 12, wherein the camera viewfinder (10) has at least one electrically controllable actuator (30, 32) that is configured to adjust the at least one adjustable free-form surface mirror (20, 22, 24); and wherein the control and evaluation device (44) is configured to transmit a control command to the actuator (30, 32) on the basis of the determined degree of the vision defect of the user to adjust the at least one adjustable free-form surface mirror (20, 22, 24) such that the determined vision defect is at least partially adjusted. ### Claim 15 (depends on 14) A camera viewfinder (10) in accordance with claim 14, wherein the camera viewfinder (10) has a storage device that is connected to the control and evaluation device (44) and that is configured to store user-specific data records, with the control and evaluation device (44) being configured to control the actuator (30, 32) on the basis of a data record transmitted by the storage device, and with the user-specific data records representing at least one of the following: the degree of the vision defect of a respective user, or control commands to the actuator (30, 32) required to compensate the vision defect of a respective user. ### Claim 16 (depends on 1) An electronic camera comprising a camera viewfinder (10) in accordance with claim 1. ### Claim 17 A camera viewfinder comprising at least: an electronic display configured for displaying an image; a first mirror that reflects the image displayed by the electronic display, and a second mirror that reflects the image displayed by the electronic display and reflected by the first mirror, wherein at least one of the first mirror and second mirror is a free-form surface mirror that has a reflective surface formed as a free-form surface that has no continuous translation symmetry or rotational symmetry and which is not deformable, wherein at least one of a position and an orientation of the free-form surface mirror is adjustable during use of the camera viewfinder, wherein the free-form surface mirror is adjustable during use of the camera viewfinder in accordance with at least one of the following: a) the free-form surface mirror can be tilted about at least one axis; and b) the free-form surface mirror is movable in a translatory manner in at least one spatial direction so that the at least one free-form surface mirror is movable in a straight line along the at least one spatial direction. ### Claim 18 A camera viewfinder of an electronic camera, comprising an electronic display apparatus that is configured for the display of images that are recorded by an image sensor of the electronic camera; and at least two mirrors for reflecting the images displayed by the display apparatus, of which at least one mirror is a free-form surface mirror whose reflective surface is formed as a free-form surface that has no continuous translation symmetry or rotational symmetry, wherein at least one of the free-form surface mirrors is adjustable during use of the electronic camera to at least partially compensate a vision defect of a user, and wherein the at least one of the free-form surface mirrors is not deformable. ### Claim 19 A camera viewfinder (10) of an electronic camera, comprising an electronic display apparatus (12) that is configured for the display of images that are recorded by an image sensor of the electronic camera; and at least two mirrors (20, 22, 24) for reflecting the images displayed by the display apparatus (12), of which at least one mirror is a free-form surface mirror (20, 22, 24) whose reflective surface is formed as a free-form surface that has no continuous translation symmetry or rotational symmetry and which is not deformable, wherein at least one of the free-form surface mirrors (20, 22, 24) is adjustable during use of the electronic camera to at least partially compensate a vision defect of a user, wherein the at least one free-form surface mirror (20, 22, 24) is adjustable during use of the electronic camera in accordance with at least one of the following: a) the at least one adjustable free-form surface mirror (20, 22, 24) can be tilted about at least one axis; and b) the at least one adjustable free-form surface mirror (20, 22, 24) is movable in a translatory manner in at least one spatial direction so that the at least one free-form surface mirror is movable in a straight line along the at least one spatial direction, the camera viewfinder further comprising: a light source; a control and evaluation device that is configured to activate the light source to generate a punctiform light spot on the retina of the eye of the user; an optoelectronic receiver apparatus connected to the control and evaluation device for receiving light scattered back from the eye, with the control and evaluation device being configured to determine a degree of a vision defect of the user on the basis of the received light; and at least one electrically controllable actuator that is configured to adjust the at least one adjustable free-form surface mirror, wherein the control and evaluation device is configured to transmit a control command to the actuator on the basis of the determined degree of the vision defect of the user to adjust the at least one adjustable free-form surface mirror such that the determined vision defect is at least partially adjusted.