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EP-4741911-A2 - COMPACT FOLDED TELE CAMERAS WITH SLIM HIGH IMAGE QUALITY OPTICAL IMAGE STABILIZATION ACTUATOR

EP4741911A2EP 4741911 A2EP4741911 A2EP 4741911A2EP-4741911-A2

Abstract

Folded Tele cameras comprising a lens including a plurality of lens elements divided into a first lens group (G1) and a second lens group (G2) and having an EFL in the range of 8mm<EFL<40mm, an image sensor, an optical path folding element (OPFE) for folding a first optical path (OP1) to a second optical path (OP2), wherein G1 is located at an object side of the OPFE, and wherein G2 is located at an image side of the OPFE, the OPFE having a height H O measured along OP1, and an optical image stabilization (OIS) actuator operational to perform OIS and including a single motor for performing OIS along a first OIS direction by jointly rotating G1 around a G1 rotation axis by a G1 rotational stroke (Rot G1 ) and by rotating the OPFE around an OPFE rotation axis by an OPFE rotational stroke (Rot OPFE ) < Rot G1 , wherein the G1 rotation axis and the OPFE rotation axis are parallel to each other and perpendicular to both OP1 and OP2, and wherein a distance d ROT between the G1 rotation axis and the OPFE rotation axis fulfills d ROT < H O /2.

Inventors

  • GOLDSTEIN, KOBI
  • GOLDENBERG, EPHRAIM
  • WEITZ, Tom

Assignees

  • Corephotonics Ltd.

Dates

Publication Date
20260513
Application Date
20241106

Claims (15)

  1. A folded camera, comprising: an image sensor; an optical path folding element (OPFE) for folding a first optical path (OP1) to a second optical path (OP2); a lens that includes a plurality of lens elements divided into a first lens group (G1) located at an object side of the OPFE and a second lens group (G2) located at an image side of the OPFE; and an optical image stabilization (OIS) actuator comprising a first lever, a second lever, and a lever reference point defining a G1 rotation axis and an OPFE rotation axis parallel to the G1 rotation axis, wherein the OIS actuator is operational to perform OIS along a first OIS direction by jointly rotating G1 around the G1 rotation axis by a G1 rotational stroke (RotG1), and by rotating the OPFE around the OPFE rotation axis by an OPFE rotational stroke (RotOPFE) < RotG1.
  2. The folded camera of claim 1, wherein the lens has an effective focal length (EFL) in the range of 8mm<EFL<40mm.
  3. The folded camera of claim 1, wherein the G1 rotation axis is perpendicular to both OP1 and OP2.
  4. The folded camera of claim 1, wherein a straight line connecting the OPFE rotation axis and the lever reference point forms an angle α with OP1, wherein a straight line connecting the G1 rotation axis and the lever reference point forms an angle β with OP1, wherein a straight line connecting the G1 rotation axis and the lever reference point forms an angle γ with OP2, and wherein 60deg < α < 120deg, 30deg < β < 90deg and 0deg < γ < 90deg.
  5. The folded camera of claim 4, wherein 80deg < α < 100deg and 50deg < β < 70deg.
  6. The folded camera of claim 4, wherein the first lever is a G1 lever fixedly coupled to G1 and having a length LG1 from a G1 ball bearing to the lever reference point, wherein the second lever is an OPFE lever fixedly coupled to the OPFE and having a length LOPFE from an OPFE ball bearing to the lever reference point, wherein a lever ratio LG1:LOPFE and angles α, β and γ define a rotational stroke ratio RotOPFE:RotG1in a range of 1:1.25 to 1:3, and wherein LG1:LOPFE is in a range of 0.5:1 to 1:2.
  7. The folded camera of claim 6, wherein 0.75:1 ≤ LG1:LOPFE ≤ 0.95:1 and 1:1.4 ≤ RotOPFE:RotG1 ≤ 1:8.
  8. The folded camera of claim 1, wherein the G1 rotation axis, the lever reference point and the OPFE rotation axis lie on a straight line, wherein the first lever is a G1 lever fixedly coupled to G1 and having a length LG1 from a G1 ball bearing to the lever reference point, wherein the second lever is an OPFE lever fixedly coupled to the OPFE and having a length LG1 from an OPFE ball bearing to the lever reference point, LG1< LOPFE, wherein a lever ratio LG1:LOPFE is equal to a rotational stroke ratio RotOPFE:RotG1 in a range of 1:1.25 to 1:3, and wherein LG1:LOPFE is in a range 1:1.25 to 1:3.
  9. The folded camera of claim 1, wherein the lever reference point is a rolling hinge.
  10. The folded camera of any of the previous claims, wherein the OIS actuator includes two ball-bearings that define the G1 rotation axis, two ball-bearings that define the OPFE rotation axis and one ball-bearing that defines the lever reference point.
  11. The folded camera of any of the previous claims, wherein the folded camera has a camera module height HM measured along OP1that fulfills 5mm ≤ HM ≤ 15mm.
  12. The folded camera of claim 11, wherein HM ≤ 12.5mm.
  13. The folded camera of any of the previous claims, wherein the folded camera has a first camera module region with a camera module height HM and a second camera shoulder region with a camera shoulder region height HS, wherein HM and HS are measured along OP1, and wherein HS < HM - 2mm.
  14. The folded camera of any of the previous claims, wherein the folded camera is included in a mobile device.
  15. The folded camera of claim 14, wherein the mobile device is a smartphone.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority from U.S. provisional patent applications No. 63,597,017 filed November 8, 2023, which is incorporated herein by reference in its entirety. FIELD The presently disclosed subject matter is generally related to the field of digital cameras. DEFINITIONS In this application and for optical and other properties mentioned throughout the description and figures, the following symbols and abbreviations are used, all for terms known in the art: Total track length (TTL): the maximal distance, measured along an axis parallel to the optical axis of a lens, between a point of the front surface S1 of a first lens element L1 that faces an object and an image sensor, when the system is focused to an infinity object distance.Back focal length (BFL): the minimal distance, measured along an axis parallel to the optical axis of a lens, between a point of the rear surface S2N of the last lens element LN and an image sensor, when the system is focused to an infinity object distance.Effective focal length (EFL): in a lens (assembly of lens elements L1 to LN), the distance between a rear principal point P' and a rear focal point F' of the lens.f-number (f/#): the ratio of the EFL to an entrance pupil diameter (or simply aperture diameter "DA"), f/# = EFL/DA. BACKGROUND Multi-aperture cameras (or "multi-cameras", of which a "dual-cameras" having two cameras is an example) are today's standard for portable electronic mobile devices ("mobile devices", e.g. smartphones, tablets, headsets, smartwatches etc.). A multi-camera usually comprises a wide field-of-view (or "angle") FOVW camera ("Wide" camera or "W" camera), and at least one additional camera, e.g. with a narrower (than FOVW) FOV (Telephoto or "Tele" camera with FOVT. FIG. 1A shows schematically an embodiment of a known folded Tele camera 100. For simplicity, such a camera may be referred to herein simply as "folded camera", with the understanding that all such folded cameras are "Tele" cameras. Camera 100 comprises a lens 102, an optical path folding element (OPFE) 104, e.g. a prism or a mirror, and an image sensor 106 having a sensor height HS. Here and in the following, a height is measured along OP1. OPFE 104 folds a first optical path ("OP1") 108 to a second optical path (OP2) 110. Lens 102 includes a plurality of N lens elements (here: N=7) numbered L1 - L7, which is divided in two lens groups, a first group 102-G1 ("G1") that includes L1 - L4 and has a thickness TG1, is located at an object side of the OPFE and has a lens optical axis which is parallel to OP1, and a second lens group 102-G2 ("G2") that includes L5-L7 and has a thickness TG2, is located at an image side of the OPFE and has a lens optical axis which is parallel to OP2, i.e. normal to sensor 106. Lens elements included in any of G1 or G2 respectively do not move relative to each other. Lens 102 has a lens width WL (measured along OP2). Here and in the following, a width is measured along an axis perpendicular to OP1. A distance between 102-G1 and OPFE 104 is marked ΔLO. A width of OPFE 104 is marked WOPFE. A TTL of camera 100 is divided into TTL1 and TTL2. TTL1 is parallel to OP1 108, TTL2 is parallel to OP2 110 and TTL=TTL1+TTL2. An aperture of camera 100 is numbered 112. A theoretical limit for a length of a camera module ("minimum module length" or "MLM"), a first height of a camera module in a "module" region ("minimum module height" or "MHM"), and a second height of a camera module in a "shoulder" region ("minimum shoulder height" or "MHS"), wherein MHM > MHS, including camera 100 is shown. MLM, MHM and MHS are defined by the smallest dimensions of the components included in camera 100. Hereinafter "HM" denotes "camera module height", or simpler just "module height", and "HS" denotes "camera shoulder height", or simpler just "shoulder height". The camera module includes a housing 114. FIG. 1B shows schematically a mobile device 120 (e.g. a smartphone) including known folded camera 100 in a cross-sectional view. Aperture 112 of camera 100 is located at rear surface 122. A front surface 124 may e.g. include a screen (not shown). Mobile device 120 has a regular region 126 of thickness ("T") and a camera bump region 128 that is elevated by a height B over regular region 126. Bump region 128 has a bump length ("BL") and a bump thickness T+B. The module region of camera 100 may be integrated into bump region 128, and the shoulder region may be integrated into regular region 126, as shown. For industrial design reasons, a small camera bump (i.e. a short BL) is desired. Camera 100 is integrated in the bump region only partially, what allows a relatively short BL. In general and for slim mobile devices, it is beneficial to minimize MHM and MHS. Especially minimizing MHM is of interest, as it allows minimizing B. For a compact camera, minimizing MLM is also beneficial. Especially minimizing R1 is of interest, as it allows mi