Releasable optical element

1. An optical element for releasable connection to a lighting module, said optical element comprising;

an outer member having a cylindrical portion, said cylindrical portion having a shoulder portion extending towards a central axis of said cylindrical portion;

an inner member having a cylindrical portion at least partially arranged within said cylindrical portion of said outer member;

wherein said optical element further comprises at least one deformable member arranged within said cylindrical portion of said outer element adjacent to said shoulder; and

at least one of said inner and said outer member comprising an optical member for modifying light emitted from said lighting module;

wherein said inner member is movable in an axial direction in relation to said outer member to compress said deformable member between a base surface of said cylindrical portion of said inner member and said shoulder portion of said cylindrical portion of said outer member; and

to expand said deformable member in a direction perpendicular to the axial direction such that the outer member is releasably connected to the inner member through a friction between deformable member and the inner member.

2. The optical element according to claim 1 , wherein said inner member is movable in the axial direction in relation to said outer member through a rotation of said inner member in relation to said outer member.

3. The optical element according to claim 2 , wherein said cylindrical portion of said inner member facing said lighting module comprises at least one structure configured to interact with at least one corresponding structure of said lighting module such that said inner member is inhibited from rotating when said outer member is rotated during mounting of said optical element on said lighting module.

4. The optical element according to claim 2 , wherein said inner member comprises screw threads configured to interact with corresponding screw threads in said outer member.

5. The optical element according to claim 2 , wherein said inner member is connected to said outer member through a bayonet coupling.

6. The optical element according to claim 1 , wherein at least one of said outer surface of said inner member and said inner surface of said outer member comprises flexible grooves configured to interact with the opposing surface when said inner member is arranged within said outer member such that said inner member remains in position in relation to said outer member through a frictional force acting between said flexible grooves and said opposing surface.

7. The optical element according to claim 1 , further comprising a lever pivotably connected to said outer member and to a connecting member which in turn is pivotably connected to said inner member, said lever being arranged so that a movement of said lever towards the central axis of said cylindrical portion of said outer member translates said inner member in an axial direction in relation to said outer member to compress said deformable member between a base surface of said cylindrical portion of said inner member and said shoulder portion of said cylindrical portion of said outer member.

8. The optical element according to claim 1 , wherein said deformable member is a deformable ring arranged along the circumference of said cylindrical portion of said outer element.

9. The optical element according to claim 1 , wherein said flexible member is an elastomer ring.

10. The optical element according to claim 1 , wherein said outer member comprises a reflector.

11. The optical element according to claim 1 , wherein said outer member comprises a diffusing element.

12. The optical element according to claim 1 , wherein said outer member comprises a phosphor element.

13. The optical element according to claim 1 , wherein said outer member comprises a lens.

14. A lighting arrangement comprising a lighting module and an optical element according to claim 1 .