# US 12,216,260 B2 · Optical system including lenses and prism for telephoto cameras > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,216,260 B2 - Document ID: US12216260B2 - Status: Granted - Kind: B2 - Application number: 18/448,853 - Filed: 2023-08-11 - Published: 2023-12-14 - Granted: 2025-02-04 - Earliest claimed: 2020-09-24 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Takeyoshi Saiga; Yoshikazu Shinohara - Web page: https://patentgrep.com/patent/US12216260B2 ## CPC - G02B 13/0035: {having three lenses} - G02B 13/007: {the beam folding prism having at least one curved surface} - G02B 13/002: {having at least one aspherical surface} - G02B 13/004: {having four lenses} - G02B 13/0065: {having a beam-folding prism or mirror} - G02B 13/02: Telephoto objectives, i.e. systems of the type + - in which the distance from the front vertex to the image plane is less than the equivalent focal length - H04N 23/55: Optical parts specially adapted for electronic image sensors; Mounting thereof - G02B 5/005: {Diaphragms (for cameras G03B9/02)} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An optical system for a camera may include a lens group having a plurality of lenses, a prism, and an image sensor. The prism may be positioned, optically, between the plurality of lenses and the image sensor along the optical transmitting path of the light. The prism may include at least four surfaces, which may fold the light within the prism at least four times to guide the light from the plurality of lenses passing through the prism to the image sensor. The prism may include multiple prisms joined together using an optical cement. The prism may include one or more aperture masks inside the prism to reduce flare. ## Claims ### Claim 1 A camera, comprising: a plurality of lenses; an image sensor; and a prism configured to: transmit light passing through the plurality of lenses through a first surface into the prism, wherein the first surface provides an initial transmission surface of the prism to receive the light passing through the plurality of lenses from a subject to be imaged at the image sensor; reflect, at a second surface of the prism, at least some of the light passing through the first surface of the prism, wherein an angle between the first surface and the second surface of the prism is in a range between 25 and 35 degrees; reflect, at the first surface of the prism, at least some of the light reflected from the second surface of the prism; reflect, at a third surface of the prism, at least some of the light reflected from the first surface of the prism; and reflect, at a fourth surface of the prism, at least some of the light reflected from the third surface of the prism to pass through the third surface out of the prism to the image sensor, such that at least some of the light transmitted through the first surface and reflected within the prism at the second surface, the first surface, the third surface, and the fourth surface reaches the image sensor to image the subject. ### Claim 2 (depends on 1) The camera of claim 1, wherein at least one of the second surface or the fourth surface of the prism includes a reflective coating. ### Claim 3 (depends on 1) The camera of claim 1, wherein at least one of the first surface or third surface of the prism includes an anti-reflective coating. ### Claim 4 (depends on 1) The camera of claim 1, wherein the plurality of lenses includes at least one of a glass lens or a plastic lens. ### Claim 5 (depends on 1) The camera of claim 1, wherein individual ones of the plurality of lenses is a spherical lens. ### Claim 6 (depends on 1) The camera of claim 1, wherein a ratio B/A is in a range between 0.2 and 0.6, wherein B represents a partial Z-height of the camera between the first surface of the prism and an image plane of the image sensor, and A represents a total Z-height of the camera between a front surface of a first lens of the plurality of lenses and the image plane of the image sensor. ### Claim 7 (depends on 6) The camera of claim 6, wherein the partial Z-height of the camera is in a range between 3.57 and 5.6 millimeters. ### Claim 8 (depends on 1) The camera of claim 1, wherein a product CD is in a range between 0.6 and 1.0, wherein C represents an optical path length of light in the prism from the light entering the prism to exiting the prism, and D represents a power of the plurality of lenses. ### Claim 9 (depends on 1) The camera of claim 1, wherein an effective focal path of the camera is in a range of 17.2 and 27.2 millimeters. ### Claim 10 (depends on 1) The camera of claim 1, wherein a ratio E/F is in a range between 0.2 and 0.8, wherein E represents a thickness of the prism between the first surface and the third surface of the prism and F represents a thickness of the plurality of lenses between a front surface of a first lens and a rear surface of a last lens of the plurality of lenses. ### Claim 11 (depends on 1) The camera of claim 1, wherein the prism includes a parallelogram prism, and wherein the first surface of the prism is parallel to the third surface of the prism and the second surface of the prism is parallel to the fourth surface of the prism. ### Claim 12 (depends on 1) The camera of claim 1, wherein the prism includes a plurality of prisms joined together using an optical cement. ### Claim 13 (depends on 12) The camera of claim 12, wherein the prism includes one or more aperture masks inside the prism configured to reduce flare. ### Claim 14 (depends on 1) The camera of claim 1, wherein the prism comprises two aperture masks at different locations inside the prism, configured to reduce flare. ### Claim 15 (depends on 14) The camera of claim 14, wherein the two aperture masks are positioned at respective joining surfaces between a rectangular prism and respective triangular prisms at opposite ends of the rectangular prism. ### Claim 16 A device, comprising: one or more cameras; and one or more processors configured to process image signals generated from the one or more cameras, wherein at least one of the one or more cameras includes: a plurality of lenses; an image sensor; and a prism configured to: transmit light passing through the plurality of lenses through a first surface into the prism, wherein the first surface provides an initial transmission surface of the prism to receive the light passing through the plurality of lenses from a subject to be imaged at the image sensor; reflect, at a second surface of the prism, at least some of the light passing through the first surface of the prism, wherein an angle between the first surface and the second surface of the prism is in a range between 25 and 35 degrees; reflect, at the first surface of the prism, at least some of the light reflected from the second surface of the prism; reflect, at a third surface of the prism, at least some of the light reflected from the first surface of the prism; and reflect, at a fourth surface of the prism, at least some of the light reflected from the third surface of the prism to pass through the third surface out of the prism to the image sensor, such that at least some of the light transmitted through the first surface and reflected within the prism at the second surface, the first surface, the third surface, and the fourth surface reaches the image sensor to image the subject. ### Claim 17 (depends on 16) The device of claim 16, wherein at least one of the second surface or the fourth surface of the prism includes a reflective coating. ### Claim 18 (depends on 16) The device of claim 16, wherein an F-number of the at least one camera is in a range between 2.2 and 2.8, and wherein an effective focal length of the at least one camera is in a range between 17.2 and 27.2 millimeters. ### Claim 19 (depends on 16) The device of claim 16, wherein the prism includes a parallelogram prism, wherein the first surface of the prism is parallel to the third surface of the prism and the second surface of the prism is parallel to the fourth surface of the prism. ### Claim 20 An optical system, comprising: a plurality of lenses; and a prism having at least four surfaces, wherein the prism is configured to: transmit light passing through the plurality of lenses through a first surface into the prism, wherein the first surface provides an initial transmission surface of the prism to receive the light passing through the plurality of lenses from a subject to be imaged at an image plane; reflect, at a second surface of the prism, at least some of the light passing through the first surface of the prism, wherein an angle between the first surface and the second surface of the prism is in a range between 25 and 35 degrees; reflect, at the first surface of the prism, at least some of the light reflected from the second surface of the prism; reflect, at a third surface of the prism, at least some of the light reflected from the first surface of the prism; and reflect, at a fourth surface of the prism, at least some of the light reflected from the third surface of the prism to pass through the third surface out of the prism to an image plane, such that at least some of the light transmitted through the first surface and reflected within the prism at the second surface, the first surface, the third surface, and the fourth surface reaches the image plane to image the subject.