Mounting of an optical element in a barrel using a flexible ring

Patent metadata

Field	Value
Publication number	US-10288095-B2
Application number	US-201514861574-A
Country	US
Kind code	B2
Filing date	Sep 22, 2015
Priority date	Sep 22, 2014
Publication date	May 14, 2019
Grant date	May 14, 2019

Abstract

An optical assembly has an optical element mounted in the cavity of a barrel. A flexible ring is in contact with one of the surfaces of the optical element. The flexible ring has ring threads engaging barrel threads within the cavity. The flexible ring has a biased state in which the ring threads press against the barrel threads, and is resiliently deformable to a compressed state allowing screwing of the flexible ring within the cavity. In one variant, multiple subassemblies each having an optical element and a flexible ring are provided in the cavity of a barrel. The optical elements of subassemblies subsequent to the first one are supported by the flexible ring of the previous subassembly. The pressing of the ring threads against the barrel threads prevents a lateral shift of the flexible ring within the cavity, eliminating the decentering observed with conventional retaining rings.

First claim

The invention claimed is:

1. An optical assembly, comprising:
a barrel defining a cavity, the barrel having an inner wall provided with a set of barrel threads;
an optical element mounted in the cavity and having opposite first and second surfaces; and
a flexible ring having an abutment peripherally engaging one of the first and second surfaces, the flexible ring having an outer surface provided with a set of ring threads engaging the barrel threads, the flexible ring comprising a gap along a section of the flexible ring and having a biased state in which the ring threads press against the barrel threads, said flexible ring being resiliently deformable to a compressed state in which an engagement of the ring threads and barrel threads allows screwing of said flexible ring within the cavity.

2. The optical assembly according to claim 1 , wherein the flexible ring comprises at least one compressible portion opposite the gap.

3. The optical assembly according to claim 2 , wherein the ring threads are distributed around the flexible ring according to three ring thread segments projecting outwardly from the outer surface of said flexible ring.

4. The optical assembly according to claim 1 , wherein the barrel threads and the ring threads have a thread profile including a load-bearing thread face perpendicular to a center axis of the cavity.

5. The optical assembly according to claim 1 , wherein the barrel threads and the ring threads have a thread profile having a triangular shape or a trapezoidal shape.

6. The optical assembly according to claim 1 , wherein the optical element is a lens, a mirror, a diffractive optical element or a pinhole.

7. The optical assembly according to claim 1 , wherein the optical element comprises:
a sleeve having opposite ends defining said first and second surfaces; and
one or more optical components mounted in the sleeve and centered with respect thereto.

8. The optical assembly according to claim 7 , wherein each of the optical components is a lens, a mirror, a diffractive optical element or a pinhole.

9. The optical assembly according to claim 1 , further comprising a seat provided in said cavity and engaging the first surface of the optical element, the abutment of the flexible ring engaging the second surface of the optical element, the optical element being thereby secured between the seat and the flexible ring.

10. The optical assembly according to claim 1 , wherein the abutment of the flexible ring engages the first surface of the optical element, said abutment thereby defining a seat for the optical element, the optical assembly further comprising a retaining ring engaging the second surface of the optical element, the optical element being thereby secured between the flexible ring and the retaining ring.

11. The optical assembly according to claim 1 , wherein the abutment of the flexible ring engages the first surface of the optical element, said abutment thereby defining a seat for the optical element, the optical assembly further comprising an additional flexible ring engaging the second surface of the optical element, the optical element being thereby secured between the flexible ring and the additional flexible ring.

12. An optical assembly, comprising:
a barrel defining a cavity, the barrel having an inner wall provided with a set of barrel threads;
a seat provided in the cavity; and
a plurality of optical subassemblies mounted in a cascade within the cavity, each comprising:
an optical element mounted in the cavity and having opposite first and second surfaces;
a flexible ring having an abutment peripherally engaging the second surface, the flexible ring having an outer surface provided with a set of ring threads engaging the barrel threads, the flexible ring having a biased state in which the ring threads press against the barrel threads, said flexible ring being resiliently deformable to a compressed state in which an engagement of the ring threads and barrel threads allows screwing of said flexible ring within the cavity;
wherein the seat engages the first surface of an innermost one of the optical elements, and the first surface of each subsequent ones of the optical elements is supported by the flexible ring of the previous subassembly within said cascade; and
wherein the flexible ring of one of the subassemblies comprises a gap along a section of the flexible ring.

13. The optical assembly according to claim 12 , wherein the flexible ring of the at least one of the subassemblies comprises at least one compressible portion along a section thereof opposite the gap.

14. The optical assembly according to claim 13 , wherein the ring threads of the flexible ring of at least one of the subassemblies are distributed around the flexible ring according to multiple ring thread segments projecting outwardly from the outer diameter of said flexible ring.

15. The optical assembly according to claim 12 , wherein the optical element of each subassembly is a lens, a mirror, a diffractive optical element or a pinhole.

16. An optical assembly, comprising:
a barrel defining a cavity, the barrel having an inner wall provided with a set of barrel threads;
a seat provided in the cavity; and
a plurality of optical subassemblies mounted in a cascade within the cavity, each comprising:
an optical element mounted in the cavity and having opposite first and second surfaces;
a flexible ring having an abutment peripherally engaging the second surface, the flexible ring having an outer surface provided with a set of ring threads engaging the barrel threads, the flexible ring having a biased state in which the ring threads press against the barrel threads, said flexible ring being resiliently deformable to a compressed state in which an engagement of the ring threads and barrel threads allows screwing of said flexible ring within the cavity;

wherein the seat engages the first surface of an innermost one of the optical elements, and the first surface of each subsequent ones of the optical elements is supported by the flexible ring of the previous subassembly within said cascade; and
wherein the flexible ring of at least one of the optical subassemblies comprises at least one resilient insert along a section of the flexible ring.

17. The optical assembly according to claim 16 , wherein the optical element of each subassembly is a lens, a mirror, a diffractive optical element or a pinhole.

18. An optical assembly, comprising:
a barrel defining a cavity, the barrel having an inner wall provided with a set of barrel threads;
an optical element mounted in the cavity and having opposite first and second surfaces; and
a flexible ring having an abutment peripherally engaging one of the first and second surfaces, the flexible ring having an outer surface provided with a set of ring threads engaging the barrel threads, the flexible ring comprising at least one resilient insert and having a biased state in which the ring threads press against the barrel threads, said flexible ring being resiliently deformable to a compressed state in which an engagement of the ring threads and barrel threads allows screwing of said flexible ring within the cavity.

19. The optical assembly according to claim 18 , wherein the barrel threads and the ring threads have a thread profile including a load-bearing thread face perpendicular to a center axis of the cavity.

20. The optical assembly according to claim 18 , wherein the barrel threads and the ring threads have a thread profile having a triangular shape or a tr

Assignees

• Institut Nat Doptique

Inventors

• Lamontagne Frédéric
• Desnoyers Nichola

Classifications

• G02B7/021

  for more than one lens · CPC title

• F16B2/065 Primary

  using screw-thread elements (F16B2/08 - F16B2/12 take precedence) · CPC title

• F16B43/004

  with a radial cut in order to improve elasticity of the washer (F16B43/005 takes precedence) · CPC title

• G02B7/026 Primary

  using retaining rings or springs (G02B7/027 takes precedence) · CPC title

• F16B2/22

  of resilient material, e.g. rubbery material {(F16B2/205 takes precedence)} · CPC title