Lens Cap with Bistable Membrane for Spring Effect

Abstract

A lens cap for protecting a lens having an optical portion, the lens cap having a base with a spring membrane, and a sidewall arranged to surround the optical portion, so as to create a cavity between the base and the optical portion. The spring membrane arranged to be movable between a deformed position wherein the spring membrane is deformed toward the optical portion, and a rest position wherein the spring membrane extends away from the optical portion.

Claims

1. A lens cap for protecting a lens having an optical portion, the lens cap comprising: a base with a spring membrane; and a sidewall extending from the base and dimensioned to fit around the lens, where the spring membrane arranged to be movable between: a first position where the spring membrane is arranged at a first distance from the optical portion, and a second position where the spring membrane is arranged at a second distance from the optical portion, the second distance greater than the first distance.

2. The lens cap according to claim 1, wherein the spring membrane is arranged to be: convex when in the second position, and concave when in the first position.

3. The lens cap according to claim 1, wherein the sidewall has an inner portion arranged to be in contact with the lens when the spring membrane is in the second position.

4. The lens cap according to claim 1, wherein the sidewall is arranged to be deformed away from the lens when the spring membrane is in the first position.

5. The lens cap according to claim 1, further comprising: an inner sidewall arranged between a center of the lens cap and the sidewall.

6. The lens cap according to claim 5, wherein the inner sidewall has an end portion arranged to be in contact with a contact surface of the lens facing the base.

7. The lens cap according to claim 6, wherein the end portion has a coating.

8. The lens cap according to claim 1, wherein the spring membrane is arranged to face the optical portion.

9. The lens cap according to claim 1, wherein the sidewall has a grip portion arranged in opposition to the spring membrane when the spring membrane is in the second position.

10. The lens cap according to claim 1, wherein the base has an outer portion arranged between the sidewall and the spring membrane.

11. The lens cap according to claim 10, wherein the outer portion is straight.

12. The lens cap according to claim 11, wherein the outer portion is perpendicular with the sidewall.

13. The lens cap according to claim 11, wherein the outer portion is arranged to be aligned with a midway position between the second position and the first position.

14. The lens cap according to claim 1, wherein the second position is a stable position.

15. The lens cap according to claim 1, wherein the spring membrane is arranged to be movable in an intermediate instable position, between the second position and the first position.

16. The lens cap according to claim 1, wherein the first position and the second position are arranged on each side of a virtual central flat position.

17. The lens cap according to claim 1, wherein the spring membrane is arranged to be: convex when in the second position, and concave when in the first position, wherein the base has a straight outer portion arranged between the sidewall and the spring membrane, and wherein the second position is a stable position.

18. The lens cap according to claim 1, wherein: the spring membrane is arranged to be: convex when in the second position, and concave when in the first position, the sidewall has an inner portion arranged to be in contact with the lens when the spring membrane is in the second position, and the sidewall is arranged to be deformed away from the lens when the spring membrane is in the first position.

19. The lens cap according to claim 1, wherein: the spring membrane is arranged to be: convex when in the second position, and concave when in the first position, and the second position is a stable position.

20. The lens cap according to claim 1, wherein: the spring membrane is arranged to be: convex when in the second position, and concave when in the first position, and the spring membrane is arranged to face the optical portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Other features, purposes and advantages of the disclosure will become more explicit by means of reading the detailed statement of the nonrestrictive embodiments made with reference to the accompanying drawings:

[0059] FIG. 1 illustrates a lens cap according to a first embodiment with the lens cap mounted on a lens, in a rest position,

[0060] FIG. 2 illustrates the lens according to the first embodiment, in a deformed position,

[0061] FIG. 3 illustrates a conventional lens cap, and

[0062] FIG. 4 illustrates the lens mounted in a camera.

DETAILED DESCRIPTION

[0063] The present disclosure relates to a lens cap for protecting lens, for example lens of camera, in particular during shipping and removing of the lens cap. This is of interest in the automotive industry in particular.

[0064] The present disclosure relates to a lens cap 100 allowing an easy removal of the lens cap 100 from a lens 200, so as to protect the lens 200 during shipping and at the time of removing the lens cap 100, and to avoid or limit any ingress of dirt or particles and the like onto an optical portion 201 of the lens 200, for better functioning of the lens 200, for example when the lens 200 is installed on a vehicle or a car.

[0065] FIG. 1 illustrates the lens cap 100 according to the first embodiment with the lens cap 100 mounted on the lens 200, in a rest position.

[0066] The lens cap 100 has a base 101 with a spring membrane 102. The spring membrane 102 is preferably made out of an elastomer.

[0067] The lens cap 100 further has a sidewall 104 arranged to surround the optical portion, so as to create a cavity 110 between the base 101 and the optical portion 201. In other words, the lens cap 100 is arranged to cover the lens 200 at the level of (or at the side of) the optical portion 201.

[0068] The spring membrane 102 is arranged to be movable between: [0069] a first position wherein the spring membrane 102 is arranged at a first distance from the optical portion 201, [0070] a second position wherein the spring membrane 102 is arranged at a second distance from the optical portion 201, and
wherein the second distance is greater than the first distance.

[0071] The first position and the second position are arranged on each side of a virtual central flat position, wherein the spring membrane 102 is virtually flat. That is, the virtual central flat position is aligned with an outer portion 103 if the base 101.

[0072] In other words, the spring membrane 102 is movable between: [0073] the first position (e.g. a deformed position) wherein the spring membrane 102 is deformed toward (or in direction of) the optical portion 201, and [0074] the second position (e.g. a rest position) wherein the spring membrane 102 extends away from the optical portion 201, that is to say in an opposite direction compared to direction of deformation of the deformed position, so as to provide a spring effect of the spring membrane 102.

[0075] The spring membrane 102 is arranged to be: [0076] convex when in the rest position, and [0077] concave when in the deformed position. The virtual central flat position is an inflection position, wherein the spring membrane change its convexity (or its concavity), that is to say change from convex to concave (and/or change from concave to convex).

[0078] In the rest position, no force is applied onto the spring membrane 102.

[0079] That is, the spring membrane 102 is arranged to project in a direction opposite from the optical portion 201.

[0080] The cavity 110 may be reduced in volume when the spring membrane 102 is in the deformed position compared to the volume of the cavity 110 in the rest position. This allows to create an overpressure in the cavity 110 when a force F is applied by an operator on the spring membrane 102. That is, the greater the force F applied, the more the spring membrane 102 deforms and the more the pressure increases in the cavity 110.

[0081] The sidewall 104 has an inner portion arranged to be in contact with the lens 200, when the spring membrane 102 is in the rest position. Preferably, an air tight contact is provided, so as to avoid any ingress of dirt in the cavity 110 during shipping.

[0082] The lens cap 100 may further have an inner sidewall 105.

[0083] The inner sidewall 105 is arranged between the sidewall 104 and a center 109 of the lens cap 100.

[0084] Preferably, the inner sidewall 105 is nearby, or abuts, a contact surface of the lens 200, at the level of an end portion 108 of the inner sidewall 105. Preferably, the contact surface is around the optical portion 201.

[0085] The end portion 105 may further have a coating to avoid any friction or stick/slip of the end portion 105, when the force F is applied on the spring membrane 102.

[0086] The spring membrane 102 is preferably arranged to face the optical portion 201.

[0087] The cavity 110 is generally speaking between the base 101, the sidewall 104 and the optical portion 201. It could be considered also that the cavity 110 is defined by the spring membrane 102, the inner sidewall 105 and the optical portion 201. That is, all in all, the definition of the cavity 110 is a space between the lens cap 100 and the optical portion 201, so as to allow for a clean area to be provided nearby (or at proximity of) the optical portion 201, and avoid any ingress of dirt and deposit of dirt onto the optical portion 201 when removing the lens cap 100. The final aim is to ensure a good and clean functioning of the lens 200, in particular its optical portion 201.

[0088] It is to be noted that the force F may be applied toward the center 109 of the lens cap 100, toward the lens 200 or toward the optical portion 201.

[0089] FIG. 2 illustrates the lens according to the first embodiment, in a deformed position.

[0090] The reference numbers are kept as far as possible between the FIGS. 1 and 2.

[0091] When the force F is applied onto the spring membrane 102, the spring membrane 102 goes to the deformed position, toward the optical portion 201, as illustrated in FIG. 2.

[0092] When the (pushing or pressing) force F is applied, the sidewall 104 may be deformed away from the lens 200 (e.g. the sidewall 104 is opened), so as to ease the removal of the lens cap 100. That is, the sidewall 104 is movable between a pinched position (when the spring membrane 102 is in the rest position), and a opened position (when the spring membrane 102 is in the deformed position).

[0093] Further, when the force F is applied onto the spring membrane 102, the end portion 108 may abut and slide on the contact surface of the lens 200, and facilitate the bending of the spring membrane 102, thereby improving the general functioning the lens cap 100. The inner sidewall 105 may finally abut (after sliding) on an inner side portion 202 of the lens 200, thereby providing an end of stroke abutment for the inner sidewall 105.

[0094] When the force F is applied, the sidewall 104 may slide, rock and/or rotate on an outer side portion 203 of the lens 200, so as to ease the removal of the lens cap 100.

[0095] The operator may need to apply a pulling force G (or a traction force G) on the sidewall 104, and preferably on a gripping portion 107 of the sidewall 104, so as to finally remove the lens cap 100. The pulling force G is preferably applied meantime the pushing force F. A preferred way of applying such forces is to apply the pushing force with the thumb and to apply the pulling force with the other fingers such as the index finger or middle finger.

[0096] That is, a high lens cleanliness in optical area is achieved without the need of additional cleaning process when unpacking at assembly line. The removal of the lens cap 100 is thereby improved.

[0097] In other words, the lens cap 100 is arranged to be elastically movable or tiltable between the first position and the second position. The spring membrane 102 is dome shaped, and may move on each side of a chord plane (or spherical cap or string plane or medium plane), between the first position and the second position. The medium plane is preferably the plane at a fixed end of the sidewall 104.

[0098] FIG. 3 illustrates a conventional lens cap 1100. The conventional lens cap 1100 may be removed from the conventional lens 1200 by applying a pulling force T. When the pulling force T is applied, a depression may occur in the conventional cavity 1110 between the conventional lens cap 1100 and a conventional optical portion 1201 of the conventional lens 1200. Thereby, dirt may enter in the conventional cavity 1110 when the conventional lens cap 1100 is removed, and pollution of the conventional optical portion 1201 may occur, thereby limiting the functioning of the conventional lens 1200.

[0099] FIG. 4 illustrates the lens mounted in a camera.

[0100] The camera is illustrated with the lens 200 integrated to it. The camera further has a lens holder 1, adhesives 2, 4, a PCB assembly, thermal pads 6, a membrane 7, a cover 8, a screw 9 and a label 10.

[0101] It will be understood that various modifications and/or improvements obvious to the person skilled in the art may be made to the various embodiments of the disclosure described in the present description without departing from the scope of the disclosure defined by the appended claims. The different embodiments can be combined whenever possible.

[0102] Unless context dictates otherwise, use herein of the word or may be considered use of an inclusive or, or a term that permits inclusion or application of one or more items that are linked by the word or (e.g., a phrase A or B may be interpreted as permitting just A, as permitting just B, or as permitting both A and B). Also, as used herein, a phrase referring to at least one of a list of items refers to any combination of those items, including single members. For instance, at least one of a, b, or c can cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c, or any other ordering of a, b, and c). Further, items represented in the accompanying figures and terms discussed herein may be indicative of one or more items or terms, and thus reference may be made interchangeably to single or plural forms of the items and terms in this written description.