Folded camera lens designs

• US 10,670,827 B2
• Filed: 04/24/2019
• Issued: 06/02/2020
• Est. Priority Date: 02/23/2017
• Status: Active Grant

• Current Assignee: Corephotonics Ltd. (Samsung Electronics Co. Ltd.)
• Original Assignee: Corephotonics Ltd. (Samsung Electronics Co. Ltd.)
• Inventors: Shabtay, Gal, Goldenberg, Ephraim, Dror, Michael, Yedid, Itay, Bachar, Gil
• Primary Examiner(s): Alexander, William R
• Assistant Examiner(s): Mebrahtu, Ephrem Z
• Application Number:
  US16/392,754
• Publication Number:
  US 20190250362A1
• Time in Patent Office: 405 Days
• CPC Class Codes: G02B 13/004 having four lenses
• CPC Class Codes: G02B 13/0065 having a beam-folding prism or mirror
• CPC Class Codes: G02B 13/009 having zoom function
• CPC Class Codes: 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
• CPC Class Codes: G02B 27/0149 characterised by mechanical features G02B27/0176 takes precedence
• CPC Class Codes: G02B 7/021 for more than one lens
• CPC Class Codes: G02B 7/08 adapted to co-operate with a remote control mechanism
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 23/58 Means for changing the camera field of view without moving the camera body, e.g. nutating or panning of optics or image sensors

Abstract

Digital cameras, optical lens modules for such digital cameras and methods for assembling lens elements in such lens modules. In various embodiments, the digital cameras comprise an optical lens module including N≥3 lens elements L_i, each lens element comprising a respective front surface S_2i−1 and a respective rear surface S_2i. In various embodiments the first lens element toward the object side, L₁ and its respective front surfaces S₁ have optical and/or mechanical properties, such as a clear aperture, a clear height and a mechanical height that are larger than respective properties of following lens elements and surfaces. This is done to achieve a camera with large aperture stop, given a lens and/or camera height.

Claims

1. A lens module for a folded camera module, comprising:

a) a barrel comprising a cavity surrounded by cavity walls configured to hold lens elements; and

b) N lens elements L₁ to L_N aligned along a lens module optical axis, wherein N is equal to or greater than 3, wherein a first lens element L₁ faces an object side, wherein only a portion of lens element L₁ is completely surrounded by the cavity walls, wherein each lens element of the N lens elements comprises a respective front surface S<sub>2i−

1</sub> and a respective rear surface S_2i, the lens element surfaces marked S_k where 1≤

k≤

2N, wherein each lens element surface S_k has a clear height value CH(S_k), and wherein clear height value CH(S₁) of surface S₁ of lens element L₁ is greater than a clear height value of each of surfaces S₂ to S_2N.

2. The lens module of claim 1, wherein the cavity walls align a center of lens element L₁ with the lens module optical axis.

3. The lens module of claim 1, wherein the portion of lens element L₁ completely surrounded by the cavity walls has a diameter smaller than a diameter of another portion of lens element L₁ that is not completely surrounded by the cavity walls.

4. The lens module of claim 2, wherein the portion of lens element L₁ completely surrounded by the cavity walls has a diameter smaller than a diameter of another portion of lens element L₁ that is not completely surrounded by the cavity walls.

5. The lens module of claim 1, wherein each of the cavity walls and of lens element L₁ has a respective extremity, and wherein at least one of the extremity of the cavity walls and the extremity of lens element L₁ are shaped such that the extremity of the cavity walls acts as a stop for lens element L₁.

6. The lens module of claim 5, wherein a cross-section of the extremity of the cavity walls has a stepped shape.

7. The lens module of claim 5, wherein a cross-section of the extremity of lens element L₁ has a stepped shape.

8. The lens module of claim 1, further comprising a cover for protecting the lens the cover covering lens element L₁.

9. The lens module of claim 8, wherein the cover has an extreme point beyond lens element L₁ toward the object side.

10. The lens module of claim 8, wherein the cover blocks light from entering a mechanical part of lens element L₁.

11. The lens module of claim 1, wherein lens element L₁ is made of glass.

12. The lens module of claim 1, wherein lens element L₁ is made of plastic.

13. The lens module of claim 1, wherein each lens element L_i is made of plastic for any 2≤

i≤

N.

14. The lens module of claim 1, wherein the cavity comprises a first portion in which lens element L₁ is located and a second portion at which at least one of the other lens elements is located, and wherein a height of the first portion of the cavity is greater than a height of the second portion of the cavity.

15. The lens module of claim 1, wherein each lens element L_i has a height H_Li for 1≤

i≤

N, wherein the barrel having a barrel height H and wherein H_L1≥

H.

16. The lens module of claim 1, wherein each lens element L_i has a height H_Li for 1≤

i≤

N and wherein H_L1≥

H_LN≥

H_L2.

17. The lens module of claim 1, wherein at least one of the lens elements has a width W_L that is greater than a lens height H_L.

18. The lens module of claim 17, wherein width W_L is greater than H_L by 10% or more.

19. The digital camera of claim 1, wherein CH(S₁)<

7 mm.

20. A digital camera, comprising:

a) a folded camera module, comprising a barrel comprising a cavity surrounded by cavity walls and N lens elements L1 to LN aligned along a lens module optical axis, wherein N is equal to or greater than 3, wherein a first lens element L1 faces an object side and wherein only a portion of lens element L1 is completely surrounded by the cavity walls; and

b) a non-folded camera module, wherein each lens element of the N lens elements in the folded camera module comprises a respective front surface S<sub>2i−

1</sub> and a respective rear surface S_2i, the lens element surfaces marked S_k where 1≤

k≤

2N, wherein each lens element surface S_k has a clear height value CH(S_k), and wherein clear height value CH(S₁) of surface S₁ of lens element L1 is greater than a clear height value of each of surfaces S₂ to S_2N.

21. The digital camera of claim 20, wherein the folded camera module is a folded Tele camera module and wherein the non-folded camera module is a non-folded Wide camera module.

22. The digital camera of claim 20, wherein the folded Tele camera module has a Tele field of view FOV_T and wherein the non-folded Wide camera module has a Wide field of view FOV_W greater than FOV_T.

23. The digital camera of claim 20, wherein the cavity walls align a center of lens element L₁ with the lens module optical axis.

24. The digital camera of claim 20, wherein the portion of lens element L₁ completely surrounded by the cavity walls has a diameter smaller than a diameter of another portion of lens element L₁ that is not completely surrounded by the cavity walls.

25. The digital camera of claim 20, wherein CH(S₁)<

7 mm.

26. A lens module for a folded camera module, comprising:

a) a barrel comprising a cavity surrounded by cavity walls configured to hold lens elements; and

b) N lens elements L₁ to L_N aligned along a lens module optical axis, wherein N is equal to or greater than 3, wherein a first lens element L₁ faces an object side, wherein only a portion of lens element L₁ is completely surrounded by the cavity walls, wherein each lens element of the N lens elements comprises a respective front surface S<sub>2i−

1</sub> and a respective rear surface S_2i, the lens element surfaces marked S_k where 1≤

k≤

2N, wherein each lens element surface S_k has a clear aperture value CA(S_k), and wherein clear aperture value CA(S₁) of surface S₁ of lens element L₁ is greater than a clear aperture value of each of surfaces S₂ to S_2N.

27. A digital camera, comprising:

a) a folded camera module, comprising a barrel comprising a cavity surrounded by cavity walls and N lens elements L₁ to L_N aligned along a lens module optical axis, wherein N is equal to or greater than 3, wherein a first lens element L₁ faces an object side and wherein only a portion of lens element L₁ is completely surrounded by the cavity walls; and

b) a non-folded camera module, wherein each lens element of the N lens elements in the folded camera module comprises a respective front surface S<sub>2i−

1</sub> and a respective rear surface S_2i, the lens element surfaces marked S_k where 1≤

k≤

2N, wherein each lens element surface S_k has a clear aperture value CA(S_k), and wherein clear aperture value CA(S₁) of surface S₁ of lens element L₁ is greater than a clear aperture value of each of surfaces S₂ to S_2N.