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US-20260126612-A1 - LINEAR BALL GUIDED VOICE COIL MOTOR FOR FOLDED OPTIC

US20260126612A1US 20260126612 A1US20260126612 A1US 20260126612A1US-20260126612-A1

Abstract

Actuators for carrying and actuating a lens having a first optical axis, the lens receiving light folded from a second optical axis substantially perpendicular to the first optical axis, comprising first and second VCM engines coupled to the lens and first and second linear ball-guided rails operative to create movement of the lens in two substantially orthogonal directions upon actuation by respective VCM engines.

Inventors

  • Gil BACHAR
  • Itay Yedid
  • Gal Shabtay
  • Ephraim Goldenberg
  • Gal Avivi
  • Itay Jerby

Assignees

  • COREPHOTONICS LTD.

Dates

Publication Date
20260507
Application Date
20260107

Claims (20)

  1. 1 . An actuator system, comprising: a first actuator for carrying and actuating a lens holder, the lens holder configured to receive a lens assembly comprising a plurality of lens elements assembled along a lens optical axis; and a second actuator for carrying and actuating a prism holder, the prism holder configured to receive a prism operational to fold light from a first optical path to a second optical path, wherein the second optical path is parallel to the lens optical axis, wherein the first actuator comprises a first magnet and a first coil and is operational to linearly actuate the lens holder along a first direction parallel to the lens optical axis, wherein the second actuator comprises a second magnet and a second coil and is operational to rotationally actuate the prism holder along a holder prism rotation axis, and wherein the first actuator is a linear ball guided actuator and the second actuator is a rotational ball guided actuator.
  2. 2 . The actuator of claim 1 , wherein the first actuator and the second actuator are physically separate.
  3. 3 . The actuator of claim 1 , wherein the prism holder rotation axis is perpendicular to the first optical path.
  4. 4 . The actuator of claim 1 , wherein the prism holder rotation axis is perpendicular to the first direction.
  5. 5 . The actuator of claim 1 , wherein the first optical path is perpendicular to the second optical path.
  6. 6 . The actuator of claim 1 , wherein the plurality of lens elements define a common lens diameter DL, wherein the first actuator has a height HA measured along a direction parallel to the first optical path, and wherein HA≤DL+0.5 mm.
  7. 7 . The actuator of claim 1 , wherein the first actuator includes at least four grooves.
  8. 8 . The actuator of claim 7 , wherein the first actuator includes four balls.
  9. 9 . The actuator of claim 1 , wherein balls used in the first actuator and in the second actuator have ball diameters in the range of 0.3-1 mm.
  10. 10 . The actuator of claim 1 , wherein each of the first actuator and the second actuator have length and/or width and/or height dimensions in the range of 3-40 mm.
  11. 11 . The actuator of claim 1 , wherein each of the first actuator and the second actuator can be contained in a box with dimension of 3×3×3 mm 3 to 40×40×40 mm 3 .
  12. 12 . The actuator of claim 1 , wherein the first actuator comprises a position sensor.
  13. 13 . The actuator of claim 1 , wherein the second actuator comprises a position sensor.
  14. 14 . The actuator of claim 12 , wherein the first actuator comprises a yoke.
  15. 15 . The actuator of claim 13 , wherein the second actuator comprises a yoke.
  16. 16 . The actuator of claim 1 , wherein the actuator is included in a folded camera, wherein the folded camera further comprises a prism, a lens assembly, an image sensor and IR filter.
  17. 17 . The actuator of claim 16 , wherein the linear actuation of the lens holder is for focusing the folded camera.
  18. 18 . The actuator of claim 16 , wherein the rotational actuation of the prism holder is for performing optical image stabilization.
  19. 19 . The actuator of claim 16 , wherein the folded camera is included in a mobile device.
  20. 20 . The actuator of claim 19 , wherein the mobile device is a smartphone.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation from U.S. patent application Ser. No. 19/185,276 filed Apr. 22, 2025 (now allowed), which was a continuation from U.S. patent application Ser. No. 18/888,195 filed Sep. 18, 2024 (issued as U.S. Pat. No. l2,298,590), which was a continuation from U.S. patent application Ser. No. 18/626,499 filed Apr. 4, 2024 (issued as U.S. Pat. No. l2,124,106), which was a continuation from U.S. patent application Ser. No. 18/077,367 filed Dec. 8, 2022 (issued as U.S. Pat. No. 11,977,720), which was a continuation from U.S. patent application Ser. No. 17/224,494 filed Apr. 7, 2021 (issued as U.S. Pat. No. 11,550,119), which was a continuation from U.S. patent application Ser. No. 16/863,239 filed Apr. 30, 2020 (issued as U.S. Pat. No. 11,048,060), which was a continuation from U.S. patent application Ser. No. 15/738,951 filed Dec. 21, 2017 (issued as U.S. Pat. No. 10,845,565), which was a 371 application from international patent application PCT/IB2017/054088 filed Jul. 6, 2017, and is related to and claims priority from U.S. Provisional Patent Application No. 62/359,222, filed Jul. 7, 2016, which is incorporated herein by reference in its entirety. FIELD Embodiments disclosed herein relate in general to actuating mechanisms (“actuators”) and in particular to voice coil motor (VCM) actuators for digital cameras. BACKGROUND High-end digital camera modules, and specifically cellphone (e.g. smartphone) digital cameras include mechanisms that enable advanced optical function such as focus or optical image stabilization (OIS). Such mechanisms may actuate (e.g. displace, shift or tilt) an optical element (e.g. lens, image sensor, mirror) to create the desired optical function. A commonly used actuator is based on voice coil motor (VCM) technology. In VCM technology, a permanent (or “fixed”) magnet and a coil are used to create actuation force. The coil is positioned in the vicinity of the magnetic field of the fixed magnet. Upon driving current in the coil, a Lorentz force is created on the coil, an in return an equal counter-force is applied on the magnet. The magnet or the coil is rigidly attached to an optical element to construct an actuated assembly. The actuated assembly is then moved by the magnetic Lorenz force. Henceforth, in this description, a VCM will be referred to also as “VCM engine” and an actuator including such a VCM (or VCM engine) will be referred to as to as “VCM actuator” or simply “actuator”. In addition to the magnetic force, a mechanical rail is known to set the course of motion for the optical element. The mechanical rail keeps the motion of the lens in a desired path, as required by optical needs. A typical mechanical rail is known in the art as “spring-guided rail”, in which a spring or set of springs is used to set the motion direction. A VCM that includes a spring-guided rail is referred to as a “spring-guided VCM”. For example, US patent application No. 20110235196 discloses a lens element shifted in a linear spring rail to create focus. For example, international patent application PCT/IB2016/052179 discloses the incorporation and use of a spring guided VCM in a folded camera structure (“FCS”—also referred to simply as “folded camera”). The disclosure teaches a lens element shifted to create focus and OIS and an optical path folding element (OPFE) shifted in a rotational manner to create OIS. Also, PCT/IB2016/052179 teaches AF+OIS in a folded actuator where the actuator dos not add to the module height. Another typical mechanical rail is known in the art a “ball-guided rail”, see e.g. U.S. Pat. No. 8,810,714. With a ball-guided rail, the lens is bound to move in the desired direction by set of balls confined in a groove (also referred to as “slit”). A VCM that includes a ball-guided rail is referred to as a “ball-guided VCM”. A ball-guided VCM has several advantages over a spring-guided VCM. These include: (1) lower power consumption, because in a spring-guided VCM the magnetic force has to oppose a spring mechanical force, which does not exist in a ball-guided VCM, and (2) higher reliability in drops that may occur during the life-cycle of a camera that includes the VCM. The actuation method in U.S. Pat. No. 8,810,714 is designed for a standard non-folded lens, where the lens optical axis is directly pointed at the object to be photographed and cannot be used in a folded camera. In view of the above, there is a need for, and it would be advantageous to have a linear ball guided VCM inside a folded camera to reduce the folded camera dimensions, in particular camera height and/or width. In addition, there is a need to show such a structure in a combination with various actuation mechanisms for the OPFEs in these cameras. SUMMARY Aspects of embodiments disclosed herein relate to VCMs to actuators including such VCMs, the actuators having linear ball-guided rails for AF and OIS in a folded camera, and to digital cameras, and in