FIELD Embodiments described herein relate to an eyeguard. More particularly, described embodiments relate to a self-closing eyeguard suitable for use with a variety of optical devices.

BACKGROUND

Eyeguards are used in conjunction with a wide range of optical devices to optimise the effectiveness of the device and increase the comfort of use. They are traditionally installed adjacent a user lens or window (collectively referred to herein as a lens) on the optical device into which the user looks, thus acting as an interface between the user and the optical device.

Eyeguards are employed for two main reasons: to increase comfort and to optimise device performance. The use of an eyeguard increases the comfort of using the device as the eyeguard, or a part thereof, is generally made of a soft material and/or is shaped for comfortable interaction with the periocular portion of a user's face. The effectiveness of the optical device can be optimised by using the eyeguard to ensure the user's eye is kept an optimal distance from the user lens - this distance may be selected to coincide with a point of convergence, such as the focal length, or to maximise the user's field of view through the device. Additionally, eyeguards are often shaped to form a continuous contact around the user's eye, thus preventing ambient light or peripheral movement from reducing the effectiveness of the device or distracting the user. The contact area and force of contact between the eyeguard and periocular portion of a user's face are key determinants of the comfort of using the optical device. An eyeguard requiring a large contact force may lead to discomfort or pain when using the optical device for long period of time.

It is desirable to be able to cover the optical device's user lens when the device is not in use; firstly to prevent the environment from damaging the lens and secondly to prevent the lens alerting a third party to the device. With respect to the first reason - the lenses and windows of some optical devices are made to a high degree of precision. This makes the accuracy and clarity of the image susceptible to degradation due to scratches from grit or oily residue from contact with the user or surroundings. It is therefore desirable to have the lens covered - and hence protected - from the environment when the user is not using the device, minimising the lens' exposure to the environment.

Concerning the second reason for covering the optical device's lens - when used in a monitoring or combat situation, it is often crucial that the user of the optical device is undetected. Uncovered lenses may pose a number of risks in this regard - they are susceptible to reflecting ambient light, alerting the third party to the optical device's presence; additionally, optical devices such as night vision goggles which comprise an internal light source may project a light from within the optical device onto the user's face as the device is removed from use, thus illuminating the user. Eyeguards such as the one described herein can be used on a variety of devices including telescopes, binoculars, telescopic sights, thermal imaging devices and night vision devices. Eyeguards as disclosed herein reduce the risk of failure due to degradation or material fatigue associated with repetitive bending of components. Furthermore, eyeguards according to the present design allow the contact force between a user and the eyeguard required to maintain the eyeguard in an open arrangement to be controlled by a manufacturer. Finally, embodiments according to the present disclosure allow the eyeguard to be dismantled to conduct cleaning or maintenance. SUMMARY OF INVENTION

An embodiment described herein provides an eyeguard for use with an optical device, the eyeguard comprising: an eyepiece defining an aperture and a first axis; a device piece for being located adjacent an optical device during use; wherein the eyepiece and device piece are configured to move relative to each other along the first axis in response to application of a force; a driver configured to move relative to one of the eyepiece and the device piece in response to relative movement of the eyepiece and the device piece; and a leaf arranged in a plane, the plane intersecting the first axis; wherein in response to movement of the driver the leaf is configured to move within the plane between a closed arrangement, in which passage of light through the aperture is obscured, and an open arrangement, in which the passage of light through the aperture is no longer obscured.

According to an embodiment is an eyeguard for use with an optical device, the eyeguard comprising: an eyepiece defining an aperture and a first axis; a device piece for being located adjacent an optical device during use; wherein the eyepiece and device piece are configured to move relative to each other along the first axis in response to the application of a force; a driver configured to rotate relative to one of the eyepiece and the device piece, about an axis parallel to the first axis, in response to relative movement of the eyepiece and the device piece; and a leaf; wherein in response to movement of the driver the leaf is configured to move between a closed arrangement, in which passage of light between the optical device and a user through the aperture is obscured, and an open arrangement, in which the passage of light between the optical device and the user through the aperture is no longer obscured.

Optionally there is more than one leaf, i.e. a plurality of leaves, for example 2, 3, 4, 5 or 6. Each leaf may lie in substantially coincident planes so as to form a substantially singular planar obstruction when the leaves are closed. The eyeguard may be suitable for, or configured for, attachment to a variety of optical devices including telescopes binoculars, telescopic sights, thermal imaging devices and night vision devices. The eyeguard may be attached to the optical device and located between the optical device and a user. A user may look through the eyeguard, into the optical device. The eyeguard may be substantially tubular or annular, and it may have a substantially round external perimeter along the majority of its length, the radius of which can vary along its length, or between the components thereof.

The eyeguard, or any components thereof, may be made of plastic, composites or metal. The eyeguard or components thereof may be made of a thermoplastic, thermoset plastic, CFRP, GFRP or aluminium.

Optionally, there is no glass or plastic optical lens or window within the eyeguard. It can thus be hollow when in the open arrangement. The eyeguard or its components may be injection moulded, die cast or fabricated. The device piece, driver and parts of the eyepiece may be rigid so as not to bend during use. Parts of the eyepiece which are configured to be in contact with the user during use may be made of a flexible material.

Parts of the eyepiece configured to contact the periocular portion of a user's face may be made of a flexible plastic or rubber.

The eyepiece may be made of a waterproof material.

Although embodiments are described as being for interaction with a periocular portion of a user's face. It is to be understood that embodiments may be modified such that they contact and are used with other parts of the user's face or body. For example, part of the eyeguard may contact a user's forehead, or the eyepiece and device piece may be moved by a force applied by a user's hand, rather than the periocular portion of their face. The eyepiece may be configured such that a periocular portion of a user's face can be comfortably located adjacent the eyepiece and the user can look through the aperture along the first axis. As such, the eyepiece may be an eye cup or an eye ring.

The eyepiece may be ergonomically designed such that it is shaped to support the periocular portion of a user's face.

The eyepiece may be cushioned.

The eyepiece may be designed so as to maximise comfort, but also to ensure the optical device is used effectively. This may be achieved by ensuring a complete contact is present between the periocular portion of the user's face and the eyeguard.

The size of the eyepiece or eyeguard as a whole may be designed so as to ensure the user's eye is maintained at an optimal distance from the device lens. The eyepiece may be configured to accommodate both eyes of a user.

The first axis may be located through the middle of the aperture and may define a central axis of the eyeguard. The eyeguard, or components of the eyeguard, may be substantially axisymmetric about the first axis. During use, a user's eye may be substantially aligned with the first axis such that the user looks through the aperture along the first axis.

The eyeguard as a whole and/or each of the eyepiece, device piece and driver components may be substantially tubular. As such, in use, the user may look through the eyeguard into the optical device. As such, in some embodiments of the present disclosure, the first axis extends through the centre of the eyeguard and represents the user's line of sight, through the eyeguard, into the optical device. The eyepiece may comprise a plurality of separable components, these components may be removably attachable to each other. The plurality of components may comprise snap fit connections such that they can connect to become an eyepiece.

The eyeguard may be configured to move from a first configuration, in which a user's view through the eyeguard is obscured, to a second configuration, in which a user's view through the eyeguard is no longer obscured, upon application of an external force along the first axis. The eyeguard may further be configured to go from the second configuration to the first configuration, automatically, upon removal of the external force. The eyepiece and device piece may move relative to each other along the first axis when the eyeguard moves between the first and second configuration. The force may be provided by a user pressing the periocular portion of their face against the eyepiece.

The or each leaf may be movable between an open and closed arrangement, or position. When the eyeguard is in a first configuration, a leaf or a plurality of leaves may be in a closed arrangement. When the eyeguard is in a second configuration, a leaf or a plurality of leaves may be in an open arrangement. Relative movement of the eyepiece and device piece may, directly or indirectly, move the or each leaf between the open and closed arrangements. When the leaf or leaves are in a closed arrangement, the passage of light between an optical device and a user, through the eyeguard may be obscured. When the passage of light is obscured, a line of sight through the eyeguard may be blocked or partially blocked by the leaf (or the leaves). The plane of the or each leaf may be offset from that of the aperture, but may still obscure the passage of light between the optical device and a user, though that aperture.

The or each leaf may be configured to selectively close the line of sight through the eyeguard. The leaf might seal off an optical path, thus sealing off an optical device lens or window from the environment. This ensures the environment cannot damage the lens and that light cannot reflect off of, or be emitted from, the lens to the environment. The leaf might be a light shield.

In some embodiments, a user's view through the eyeguard may be reduced or hindered rather than eliminated when the leaf is in a closed arrangement.

When in the closed arrangement, one or more leaves may polarise light passing through the eyeguard, or filter the light, e.g. only letting selected wavelengths pass through, rather than blocking all light.

The eyepiece may comprise an eyecup for supporting and locating a user's eye and a support ring for supporting the device part relative to the eyepiece.

The eyecup may be configured to be in contact with the user during use. In use, a user may push the periocular portion of their face against the eyecup.

The eyecup may be designed to comfortably support the periocular portion of a user's face. The eyecup may be cushioned or padded. The support ring may comprise a driver support flange for locating and supporting the driver. The support flange may comprise a funnel section which defines an orifice. The support flange may comprise a bearing surface, against which a surface of the driver moves. An inner surface of the orifice may be the bearing surface. The device piece may be configured to attach, retain, restrain or secure the eyeguard to an optical device. The device piece may comprise an attachment means or attachment device. Example attachment means or attachment devices may include, but are not limited to, a threaded section, a slot and protrusion snap fit, clips or an interference fit. The eye piece may be an attachment ring.

The eyepiece and device piece may be configured to slide or translate relative to each other. In alternative embodiments, the eyepiece and device piece may be configured to move relative to each other in a direction other than along the first axis.

In an embodiment of an eyeguard, the support ring may comprise a first annular wall. The device piece may comprise a second annular wall, configured to be arranged concentrically with the first annular wall. The support ring and device piece are optionally prevented from rotating relative to each other, for example by a peg, a dowel, a screw or a locking device or interface between the two.

The support ring may be rigid and substantially tubular. The support ring may comprise an annular wall which constitutes an external surface of the eyeguard. The device piece may be rigid and be substantially tubular. The eyepiece and/or device piece may comprise a plurality of substantially tubular portions. The device piece may comprise an annular wall. The annular wall of the device piece may locate radially inwardly, or outwardly, of the annular wall of the support ring. The two annular walls may overlap and be configured to slide relative to each other along the first axis.

The support ring and device piece may be prevented from rotating relative to each other by means of a screw, dowel or peg inserted through a hole in one of the annular walls engaging a slot aligned with the first axis in the other of the annular walls.

The support ring and device piece may be prevented from rotating relative to each other by means of a projection protruding from one of the annular walls engaging a slot aligned with the first axis in the other of the annular walls. The annular walls of the support ring and device piece may be configured to be rotationally fixed relative to each other. The two annular walls may be prevented from rotating relative to each other by a protrusion in one of the walls mating with a slot in the other wall. A slot will allow the protrusion (and thus wall) to move in one direction relative to the other wall i.e. the support ring and device piece may move along the first axis relative to each other, but not rotate relative to each other.

The eyeguard may be configured to move between a first configuration, in which the leaf is in a closed arrangement, and a second configuration, in which the leaf is in an open arrangement; and the eyeguard may further comprise a resilient member configured to bias the eyeguard from the second configuration to the first configuration.

The eyepiece and device piece may be configured to move relative to each other under the action of a resilient member. A resilient member may be configured to move the eyepiece and device piece relative to each other along the first axis. The eyeguard may be configured to move from the second configuration to the first configuration in response to an external force along the first axis being removed, wherein the force exerted by the resilient biasing member is unopposed. In alternative embodiments, a resilient biasing member may bias the eyeguard from the first configuration to the second configuration.

In alternative embodiments, no resilient biasing member may be present and a user may be required to manually move the eyeguard between a first and second configuration in both directions.

The eyeguard may comprise a plurality of resilient members.

In some embodiments, a first resilient biasing member may bias the eyeguard from the first configuration to the second configuration, and a second resilient biasing member may bias the eyeguard from the second configuration to the first configuration. The first and second resilient biasing members may have different (and predetermined) biasing strengths. The or each resilient member may comprise a spring or compressible material. The resilient member, or at least one of the resilient members may be located around the periphery of the aperture. The resilient member, or at least one thereof, may be located adjacent, or around the periphery of the driver.

The resilient member, or at least one thereof, may be located substantially between the eyepiece and the device piece. Such a resilient member may be configured to move the eyepiece relative to the device piece along the first axis. The resilient member may be configured to return the eyeguard to the first configuration once a user removes their eye from the eyepiece.

Use of one or more resilient member may allow a manufacturer to specify the restoring force present in the eyeguard by selecting the stiffness of the or each resilient member. This may allow a manufacturer to specify the force required to maintain the eyeguard in a second configuration and thus the force the eyeguard exerts on the periocular portion of a user during use. The driver may be a rotor that moves by rotating about an axis parallel to the first axis.

The driver may be a rotor that moves by rotating about the first axis.

The driver may be configured to move relative to the eyepiece, the device piece or both of the eyepiece and the device piece, in response to relative movement of the eyepiece and device piece. The movement of the driver may be rotation (e.g. about the first axis), translation (e.g. along the first axis) or a combination of the two.

The driver may be restrained relative to or connected to one of the eyepiece or the device piece.

The driver may be part of one of the eyepiece or device piece; as such, the eyepiece or device piece may comprise the driver. The driver may be configured to actuate the leaf. The driver may be configured to actuate the leaf from a closed arrangement to an open arrangement and/or from an open arrangement to a closed arrangement. The eyeguard may comprise a driver actuating means or device, configured to move the driver in response to relative movement of the eyepiece and device piece. The driver actuating means or device may be configured to move the driver relative to one of the eyepiece and the device piece in response to relative movement of the eyepiece and the device piece.

The driver may be substantially tubular, its axis extending along the first axis.

The driver may comprise one of a helical groove and a protrusion. One of the eyepiece and the device piece may comprise the other of a helical groove and a protrusion. The protrusion may engage the groove. Relative movement of the driver and the one of the eyepiece and the device piece may cause the protrusion to move along the groove and the driver to rotate about the first axis relative to the one of the eyepiece and the device piece. The helical groove may be a helical slot. The helical groove may only partially penetrate the surface on which it is located (i.e. may represent a reduction in thickness), or may entirely penetrate through the thickness of the component on which it is located. For example, the helical groove may be an elongated helical indent on a surface, or may be an elongated helical hole through a surface.

The protrusion may be a moulded protrusion, e.g. an integral feature of the component to which it is attached, or may be a separate feature. The protrusion may be a screw or dowel. The protrusion may be fixed or restrained relative to the driver, eyepiece or device piece.

A screw or dowel may be inserted through an outer surface of the driver, eyepiece or device piece to extend from an inner surface. A screw or dowel may be inserted through a support ring of the eyepiece to extend from a block on the inside of the eyepiece. The block may be configured to abut an outer surface of the driver such that the screw or dowel can engage a groove on the outer surface of the driver. A helical groove and protrusion may be an example of a driver actuating means or device. The relative movement causing the rotation of the driver about the first axis may be movement along the first axis. The helical groove may be configured to interact or engage with a protrusion. Due to the interaction between the helical groove or slot and protrusion, relative movement along an axis of the two components may cause relative rotation about that axis.

The eyepiece may define a ring and may have at least one inwardly-extending radial protrusion. The eyepiece may define an orifice and the orifice may have at least one inwardly-extending protrusion. The driver may be located concentrically inside the eyepiece. The driver may comprise the helical groove on its outer surface. The radial protrusion may mate with the helical groove.

An eyeguard may comprise a plurality of helical grooves and protrusions.

The protrusion may be part of or restrained with respect to one of the eyepiece or device piece. The driver may be configured to translate along the first axis relative to the protrusion. The relative translation of the driver with respect to the protrusion may cause the protrusion to traverse the length of the helical groove or slot, causing the driver to rotate about the first axis relative to the protrusion. A first feature may translate or rotate relative to a second feature even if the first feature does not move in real terms (i.e. with respect to the optical device). Furthermore, in some embodiments the location of the groove/slot and protrusion may be switched (e.g. the driver comprises a protrusion and the eyepiece/device piece comprises a helical slot).

The eyepiece, device piece and protrusion may be rotationally stationary with respect to the optical device during use and the helical groove or slot and protrusion may cause the driver to rotate relative to the eyepiece, device piece and protrusion. In an embodiment, the driver may comprise a helical groove or slot. A leaf or a leaf actuating means or device may comprise a protrusion configured to interact with the helical groove or slot. The driver may be rotationally restrained relative to one of the eyepiece and device piece. The driver may be configured to translate (e.g. along the first axis) relative to the leaf or a leaf actuating means or device in response to relative movement of the eyepiece and the device piece. In response to this relative movement, the protrusion may traverse the length of the helical groove or slot. The leaf may (or the leaf actuating means or device may cause the leaf to) rotate (e.g. between the open and the closed arrangement) relative to at least one of the driver, the eyepiece, the device piece and the optical device, in response to relative movement along the first axis of the driver and the leaf or leaf actuating means or device.

Where there is a plurality of leaves, they can all similarly rotate in response to the movement of the driver.

The driver may rotate, or cause rotation, in response to movement along an axis due to the outer profile of the driver. As such, a driver may rotate, or cause rotation, in response to relative movement of the eyepiece and the device piece by means of a camming action between the cam and one of the eyepiece and device piece, or leaf and leaf actuating means or device.

An eyeguard according to an embodiment may comprise a leaf actuating means or device. A leaf actuating means or device may be configured to locate the leaf or leaves within the eyeguard. A leaf actuating means or device may be configured to, in response to movement of the driver, move the leaf or leaves within the plane between a closed arrangement and an open arrangement. A leaf actuating means or device may comprise mounting points, i.e. constraints, to which one or more leaf is attached. A leaf actuating means or device may comprise pins about which the one or more leaf can rotate.

A leaf actuating means or device may comprise a plurality of features or parts of other components which are configured to move the or each leaf, within the leafs plane, between a closed and open arrangement. A leaf actuating means or device may comprise an anchor; wherein the anchor may be constrained to be fixed with respect to one of the eyepiece and the device piece. A leaf actuating means or device may comprise a constraint with respect to any of the driver, eyepiece and device piece. A leaf actuating means or device may comprise a recess in which the leaves are located.

In other embodiments, a leaf actuating means or device may be omitted and the or each leaf may be mounted directly on the eyepiece or device piece.

The eyeguard may comprise a plurality of leaves. Each leaf may be configured to partly obscure the passage of light through the aperture when the leaves are in a closed arrangement.

An eyeguard may comprise a leaf arrangement (which may optionally comprise a leaf or plurality of leaves). The leaf arrangement may selectively have a closed arrangement, in which passage of light between the optical device and a user through the aperture is obscured, and an open arrangement, in which the passage of light between the optical device and the user through the aperture is no longer obscured.

It will be appreciated that discussion relating to "the leaf" can be interpreted as also applying to a "leaf arrangement" as well as to "at least one leaf" or "each leaf" when a plurality of leaves are provided,.

The leaves may take the form of an openable and closable iris.

The leaves may be configured to tessellate such that the passage of light through the aperture is obscured when the leaves are in a closed arrangement. Collectively, the leaves may obscure the passage of light through the aperture.

The leaves may be configured to overlap such that the passage of light through the aperture is obscured when the leaves are in a closed arrangement. The edges of a plurality of leaves may abut or overlap each other when the leaves are in a closed arrangement, and preferably they lie in substantially common planes.

The or each leaf may be a flat sheet, or disc. Each leaf may be substantially shaped like a sector of a circle. The or each leaf may be opaque or translucent.

Where a plurality of leaves is provided, each leaf may be arranged in its own plane, or a plurality of leaves may be arranged in the same plane. This may be the case when the leaves are in one of, or both, of an open arrangement and a closed arrangement.

The or each leaf may move within its own plane, between a closed and an open arrangement. In such embodiments, the or each leaf may lie in the same plane when it is in both a closed and an open arrangement. If there is an out-of-plane translation, however, the or each leaf may be parallel to its position when in a closed arrangement, when in an open arrangement, i.e. the position of the or each leaf when in an open arrangement is parallel to that of the or each leaf, respectively, when in a closed arrangement. A plurality of leaves may form a substantially conical shape when in a closed arrangement, with each leaf moving in its own plane, but the plane of each leaf being different to those of the other leaves.

The leaf may comprise a shaped edge, the shaped edge shaped such that the leaf does not protrude over one or both of the optical and linear footprint of the aperture when in an open arrangement. The leaf may comprise a curved edge, shaped to conform to the outer edge of the aperture such that the leaf does not obscure the passage of light through the eyeguard when in an open arrangement, thus avoiding the optical footprint with the minimal radial movements.

The leaf may comprise an edge configured to seamlessly abut, or tessellate, with the shaped or curved edge when the leaf is in a closed arrangement. This can be a different edge to the shaped or curved edge due to the rotation of the leaf as it opens. Such an edge may instead be configured to overlap by a constant amount.

The leaf may be configured to rotate between the closed arrangement and the open arrangement.

The leaf may rotate from an open position, in which it does not obscure the passage of light through the eyeguard to a closed position, in which it does obscure the passage of light through the eyeguard. The axis of rotation of the leaf may be parallel to the first axis.

The rotation of the leaf may be within the plane of the leaf. As such, if the leaf is substantially flat, the leaf may rotate about an axis perpendicular to the plane of the leaf. In such embodiments, the leaf will be within the same plane when in both an open and closed arrangement.

The leaf may be arranged perpendicularly to the first axis in both the closed and open arrangement. Each leaf may be arranged perpendicularly to the first axis in both the closed and open arrangement

The leaf may be constrained with respect to the driver at a first location on the leaf and with respect to an anchor at a second location on the leaf; the anchor may be constrained to be fixed with respect to one of the eyepiece and the device piece such that relative rotation between the driver and the anchor causes the leaf to move between the closed arrangement and the open arrangement.

A leaf actuating means or device may comprise the above features.

One of the eyepiece and the device piece may comprise the anchor.

A constraint at one of the first location and the second location may be provided by a pin engaging a slot.

The leaf may comprise a hole and may be constrained with respect to the driver to rotate about a pin; the device piece may comprise the anchor; the anchor may comprise a pin; and the leaf may comprise a slot configured to engage the anchor pin; wherein the leaf hole and leaf slot are arranged such that as the driver rotates relative to the device piece, the leaf rotates about the hole and the anchor pin traverses the slot.

The leaf may be mounted at a first location and a second location. At one location the leaf may be mounted or restrained with respect to the driver which moves relative to one of the eyepiece and the device piece. At the other location the leaf may be mounted or restrained with respect to whichever of the eyepiece and the device piece that the driver moves relative to. The relative movement between the two restraints may cause the leaf to move between a closed and open arrangement. The leaf may be constrained by means of a pin joint or a flexible attachment. The leaf may be constrained by means of a pin engaging a slot. The leaf may be constrained by means of a cam surface and 'follower'. Examples of cam surfaces may be a curved edge surface or internal surface of a slot/groove on the leaf. Examples of a 'follower' may include a pin, protrusion or edge on one of the driver, eyepiece, device piece or leaf actuating means or device. As the driver moves, the 'follower' may engage the cam surface, and the shape of the cam surface and location of the other constraint of the leaf (which may be a pin joint) may cause the leaf to rotate or translate between an open and closed arrangement. The leaf may be constrained with respect to one of the driver and the anchor to rotate about a pin and constrained with respect to the other of the driver and the anchor by a cam contact such that as the driver moves relative to the anchor the cam contact causes the leaf to rotate about the pin. The driver may rotate with respect to one of the eyepiece or the device piece and may be located concentrically with the one of the eyepiece or device piece that it rotates relative to. The leaf may comprise a pin connection with respect to one of the driver and the one of the eyepiece or device piece that the driver rotates relative to and a pin- in-a-slot with the other. The two pins may be aligned radially from the first axis when the leaf is in an open arrangement, such that relative rotation of the driver with respect to the one of the eyepiece or device piece that it rotates relative to causes the leaf to rotate about the pin connection into a closed arrangement.

The leaf may be located within a recess in at least one of the eyepiece, device piece and driver.

Alternatively, the leaf may be located within a recess in a leaf actuating means or device, if present. The profile of the recess may correspond to the outer edges of the or every leaf when the leaf or leaves is in an open arrangement.

The eyepiece and device piece may be assembled to form the eyeguard. The leaf may be configured to be removable without having to disassemble the rest of the eyeguard. The leaf may be configured to be removable from the rest of the eyeguard without having to disconnect the eyepiece and device piece. The mounting or constraints between the leaf and the eyeguard may be accessible when the eyeguard is in an assembled state, such that a user can remove the leaves without having to disassemble the eyeguard. This will allow a user to remove the leaf or leaves for replacement, cleaning or maintenance without disposing of, or disassembling, the entire eyeguard.

An eyeguard according to an embodiment may comprise a retainer plate.

A retainer plate may be configured to cover the leaf. The retainer plate may be configured to lie above the leaf in a plane parallel to that of the leaf.

A retainer plate may cover the locations of the constraints of the leaf (e.g. the first and second location).

A retainer plate may be configured to shield the leaf when the leaf is in the open arrangement. The retainer plate may be shaped so that it does not impinge upon the passage of light through the eyeguard. The retainer plate may be configured to cover the leaf only when the leaf is in the open arrangement (i.e. when the leaf does not obscure the view of a user looking through the aperture). The retainer plate may protect the leaf from damage when it is in an open and/or closed arrangement. The retainer plate may prevent the ingress of dirt in between the leaf and the driver and eyepiece/device piece.

The retainer plate may be attachable to the driver, eyepiece or device piece. The retainer plate may comprise an orifice corresponding to the profile of the aperture or the passage through which light may pass during use of the eyeguard. The outer profile of the retainer plate may correspond to a recess, in which the leaf may be located. The retainer plate may comprise fixings to attach the retainer plate to the rest of the eyeguard. Examples of fixings may include rivets, screws or snap fit attachments.

The retainer plate may be configured to be removable without having to disassemble the rest of the eyeguard.

The retainer plate may be configured to be removable from the rest of the eyeguard without having to disconnect the eyepiece and device piece.

The fixings may be accessible when the eyeguard is in an assembled state, such that a user can remove the retainer plate without having to disassemble the eyeguard. As such, a user may be able to access the leaf, retained by the retainer plate, without disassembling the rest of the eyeguard. This will allow a user to remove the leaf or leaves for replacement, cleaning or maintenance without disposing of, or disassembling, the entire eyeguard.

Further according to an embodiment of the present disclosure is an optical device comprising or combined with an eyeguard as disclosed herein.

Further according to an embodiment is a kit of parts for assembling into any embodiment described herein.

These and other preferred features of the present invention will now be described in further detail with reference to the accompanying drawings. DESCRIPTION OF DRAWINGS

Figure 1 is a perspective view of an eyeguard according to an embodiment;

Figure 2 is a side view of the eyeguard of figure 1 ; Figures 3A and 3B are side views of the eyeguard of figure 1 in a second and first configuration, respectively;

Figure 4 is an end view of the eyeguard of figure 1 in a second configuration;

Figure 5 is an end view of the eyeguard of figure 1 with a retainer plate removed, in a second configuration;

Figure 6 is an end view of the eyeguard of figure 1 with a retainer plate removed, in a first configuration;

Figure 7 is an enlarged detail view of figure 5;

Figure 8 is a section view of the eyeguard of figure 4 in plane Z-Z;

Figure 9 is an enlarged detail view of figure 8;

Figure 10 is a section view of the eyeguard of figure 4 in plane W-W; Figure 1 1 is an enlarged detail view of figure 10; and

Figure 12 is an exploded perspective view of an eyeguard according to an alternative embodiment. DESCRIPTION OF SPECIFIC EMBODIMENTS

Figure 1 depicts an eyeguard 10 according to an embodiment. The embodiment comprises an eyepiece 12 defining an aperture 14 and a first axis, and a device piece 16 for being located adjacent an optical device during use. The eyeguard 10 is for attaching to an optical device.

In this embodiment the device piece 16 is for attaching to the optical device and may comprise a thread for screwing onto the optical device, a snap fit, some other proprietary connection or simply a section sized to provide an interference fit. The eyepiece 12 is for receiving and abutting a periocular portion of a user's face.

During use, a user presses their eye up to the eyepiece 12 of the eyeguard 10, looking through the eyeguard 10 along the first axis towards the optical device. Upon applying pressure to the eyepiece 12, the eyepiece 12 moves along the first axis relative to the device piece 16. This movement causes the eyeguard 10 to go from a first configuration, in which a leaf, or as in this case a plurality of leaves 26, within the eyeguard are in a closed arrangement, obscuring the user's view through the eyeguard, to a second configuration, in which the leaves 26 are in an open arrangement and no longer obscuring the user's view through the eyeguard.

Figure 2 is a side view of the eyeguard 10. The eyepiece 12 comprises an eyecup 18 for supporting and locating a user's eye and a support ring 20 for supporting the device part 16 relative to the eyepiece 12.

Figures 3A and 3B are side views of the eyeguard 10. In figure 3A, a force is applied in the direction of the arrow, parallel to the first axis. Under the action of this force, the eyepiece 12 moves towards the device piece 16 along the first axis. Providing an adequate force is present, the eyeguard 10 stays in this configuration. This is a second configuration, in which the user has an unobscured view through the eyeguard 10 into the optical device.

Once the force along the first axis is removed from the eyepiece 12, the eyepiece 12 moves away from the device piece 16 along the first axis, into the first configuration.

Figure 3B illustrates the eyeguard 10 in this first configuration, in which a user's view through the eyeguard 10 is obstructed, obscured or blocked.

Figure 4 is an end view of an eyeguard 10, viewed from the device piece 16 end. The eyeguard 10 of figure 4 is in a second configuration, with the leaves 26 in an open arrangement such that a user can look through the eyeguard 10 into an optical device.

A retainer plate 22 is located within the device piece 16, surrounding the aperture 14.

The retainer plate 22 is fixed to an exposed end surface of the device piece 16, in this example by four screws 24. The retainer plate 22 entirely covers the leaves 26 when the leaves 26 are in an open arrangement, as in figure 4. The retainer plate 22 protects the leaves 26 from being knocked and keeps them clean while they are in an open arrangement.

When the leaves are in a closed arrangement, they extend out from under the retainer plate 22 and close off the aperture 14. A part of each leaf 26 is still retained, under the retainer plate 22, when the leaves 26 are in a closed arrangement. When the leaves 26 are in a closed arrangement, the retainer plate 22 covers and protects the connections, or constraints, between each leaf 26 and the driver 30 and device piece 16. This prevents the ingress of dirt, which may affect the manoeuvrability of the leaves between the open and closed arrangement. Furthermore, the retainer plate helps keep the leaves 26 connected to the driver 30 and device piece 16 by preventing the leaf 26 from moving away from the driver 30 and coming off the pins of the driver 30 and device piece 16. The retainer plate 22 has an outer profile conforming to the outer profile of a recess 28 in the device piece 16, as discussed with reference to figures 5 and 6.

Figure 5 is an end view of an eyeguard 10, viewed from the device piece 16 end. The eyeguard 10 of figure 6 is in a second configuration. Figure 5 is equivalent to figure 4 with the retainer plate 22 and screws 24 removed. Four leaves 26 are arranged adjacent the aperture 14. In figure 5, the leaves 26 are arranged in an open arrangement and do not protrude out over the edge of the aperture 14 into the passage of light through the eyeguard 10 - i.e. they do not obscure a line of sight through the aperture 14.

Figure 6 is similar to figure 5, except the eyeguard 10 of figure 6 is in a first configuration. As such, the leaves 26 form a barrier to light travelling through the eyeguard 10 and a user's view through the eyeguard 10 is entirely obscured. Each leaf 26 has a curved concave side 26a which is configured to conform to the outer profile of the aperture 14 when the leaves 26 are in an open arrangement. Adjacent this concave side 26a is a convex side 26b. The convex side 26b is designed such that when the leaves 26 are in a closed arrangement, the convex side 26b provides a slight overlap with the concave side 26a of an adjacent leaf 26. Given the rotational symmetry of the leaf 26 design, this results in a total occlusion, or closure, of the aperture 14. In other embodiments, the leaves may be designed to tessellate to provide a total closure of the aperture, rather than overlap.

The leaves 26 in figures 5 and 6 can be seen to be located within a recess 28. The recess 28 is in the device piece, and has a profile designed to house the leaves 26 when the leaves 26 are in an open arrangement. The recess 28 is as deep as the leaves 26 are thick and so the free surfaces of the leaves 26 (as shown in figures 5 and 6) are level with the surface of the device piece 16 outside the recess 28. Threaded holes can be seen in the device piece 16 between the leaves 26 for receiving the screws 24 used to fix the retainer plate 22.

Concentrically inside the device piece 16 is a driver 30. The driver 30 of the embodiment of figure 1 is configured to rotate relative to the eyepiece 12 and the device piece 16 in response to relative movement of the eyepiece 12 and the device piece 16 along the first axis. The driver 30 is a rotor configured to rotate about the first axis relative to the device piece 16.

Figure 7 is an enlarged view of the circled portion of figure 5. Figure 7 illustrates the connection points, or constraints, of a leaf 26.

The leaf 26 is constrained with respect to the driver 30 by means of a pin joint. The driver 30 comprises a pin 32 which extends through a hole 34 in the leaf 26. As such, the leaf 26 is free to rotate with respect to the driver 30 about the pin joint. The leaf is constrained with respect to the device piece 16 by means of a pin 36 extending from the device piece 16 engaging a slot 38 in the leaf 26. In the present embodiment, the device piece pin 36, or the part of the device piece 16 from which it extends, is an anchor.

Rotation of the driver 30 with respect to the device piece 16 causes the leaves 26 to move between an open arrangement and a closed arrangement. When the eyepiece 12 moves away from the device piece 16 along the first axis (caused for example by a user removing their eye from the eyeguard 10) the driver 30 rotates from the position shown in figures 5 and 7, to that shown in figure 6. In these figures this is in an anticlockwise direction. As the driver 30 rotates, the driver pin 32 of figure 7 moves upwards. Due to the pin 36 and slot 38 constraint, the leaf 26 rotates, extending into the aperture 14. As the leaf 26 rotates, the device piece pin 36 traverses the length of the slot 38. When the eyeguard 10 is in a first configuration, and the eyepiece 12 has finished moving away from the device piece 16, the leaf 26 is in the position shown in figure 6 - a closed arrangement - and the device piece pin 36 is at the opposite end of the slot 38 to that shown in figure 7.

Figure 8 is a cross section through an eyeguard 10 in plane Z-Z shown in figure 4. The driver 30, located in a circumferential groove on the inside of the device piece 16 is substantially tubular and extends towards the eyepiece 12. The support ring 20 comprises a funnel section 42 forming an orifice of narrower diameter than the support ring 20. This orifice contacts the driver 30.

Figure 9 is an enlarged view of the circled portion of figure 8. Figure 9 illustrates a dowel 40, located in a hole in a circumferential wall of the support ring 20. The dowel 40 extends from the hole into a slot 44 located in a concentrically arranged wall of the device piece 16. The dowel 40 is free to traverse the length of the slot 44 as the eyepiece 12 is moved towards and away from the device 16, along the first axis. The dowel 40 and slot 44 prevent the eyepiece 12 from rotating about the first axis relative to the device piece 16.

In other embodiments, a dowel 40 may extend through a slot in the support ring 20 and into a hole in the device piece 16. Thus, a similar mechanism may be formed, but with the location of the hole and slot switched around. In other embodiments according to the present disclosure, the hole, slot and screw arrangement may be replaced with a projection extending from one of the support ring 20 or device piece 16, mating with a slot or groove in the other of the support ring 20 or device piece 16. Turning back to figure 8, a spring assembly 46 acts as a resilient biasing member. The spring assembly 46 is located between the support ring 20 of the eyepiece 12 and the device piece 16. The spring assembly 46 is biased to separate the eyepiece 12 and the device piece 16. Once the force of a user's eye, pushing the eyepiece 12 towards the device piece 16, is removed, the spring assembly 46 moves the eyepiece 12 away from the device piece 16. The eyepiece 12 and device piece 16 separate until the dowel 40 reaches the end of its travel i.e. abuts the end of the slot 44 in the device piece. An embodiment according to the present disclosure may comprise one, two, three, four or more than four resilient biasing members. In some embodiments, a spring assembly may be omitted entirely.

Figure 10 is a cross section through an eyeguard 10 in plane W-W shown in figure 4. The eyeguard 10 of figure 10 is in a second configuration. In this configuration a user may have their eye pressed up to the eyeguard 10, moving the eyepiece 12 along the first axis and holding the eyepiece 12 in that position against the action of the biasing member 46.

Figure 1 1 is an enlarged view of the circled portion of figure 10. Figure 1 1 shows the funnel section 42, extending from the support ring 20, forming an orifice comprising a protrusion 48 which mates with a helical slot 50 in the outside surface of the driver 30.

The driver 30 is rotatably mounted within the eyeguard 10; the driver 30 is free to rotate within the circumferential groove in the device piece 16. The eyepiece 12 is rotatably constrained with respect to the device piece 16 by the dowel 40 and slot 44. As such, the eyepiece 12 cannot rotate relative to the device piece 16 and is constrained to move only along the first axis with respect to the device piece 16.

As the eyepiece 12 is moved along the first axis towards the device piece 16, either in response to a user applying a force to the eyepiece 12 along the first axis or the biasing member 46 exerting a separating force on the eyepiece 12 and device piece 16 along the first axis, the protrusion 48 moves along the helical slot 50. The funnel section 42 and protrusion 48 are prevented from rotating relative to the device piece 16, but the driver 30 is not. The driver 30 therefore is forced to rotate about the first axis as the eyepiece 12 moves along the first axis relative to the device piece 16, as the protrusion 48 traverses the helical slot 50. The rotation of the driver 30 moves the leaves 26 between an open and a closed arrangement.

In this manner, the eyeguard 10 can open and close in response to a user applying and removing a force to the eyepiece 12 with the periocular portion of their face. Figure 12 is an exploded perspective view of an eyeguard 1 10 according to a further embodiment. The eyeguard 1 10 of figure 12 is similar to that of figure 1 , with two modifications. Firstly, the eyeguard 1 10 of figure 12 does not comprise a biasing member 46. Secondly, the eyepiece 12 of eyeguard 1 10 of figure 12 does not comprise a funnel section 42 comprising a protrusion 48.

Instead of a funnel section 42 and moulded protrusion 48 configured to engage the slot 50, the embodiment of figure 12 comprises a pair of grub screws 41 as protrusions, which are inserted, through holes in the outer wall of the support wall 20 of the eyepiece 12, into blocks 43 located on the side of the support wall 20. These grub screws 41 are configured then to engage the helical slot 50 of the driver 30 upon extending radially inwardly out of the blocks 43 to perform effectively the same function as the moulded protrusion 48 in the embodiment of figure 1. The assembly of the eyeguard 1 10 of figure 12 is largely similar to that of the embodiment of figure 1. The eyecup 18 and support ring 20 are connected to form the eyepiece 12. The driver 30, fits inside the device piece 16 and is located in a circumferential lip of the device piece 16. The leaves 26 attach to the attachment points (i.e. the driver pin 32 and device piece pin 36) on the driver 30 and device piece 16. The retainer plate 22 fits over the top of the leaves and is attached to the device piece 16, in this example by screws 24.

A circumferential wall of the device piece is located concentrically inside a circumferential wall of the support ring of the eyepiece 12.

Dowels 40 are inserted through an aperture in the support ring wall and into apertures in the device piece wall.

The components of the eyeguard may be mechanically fastened together (e.g. by screws) or chemically bonded together (e.g. using an adhesive).

In use, a user will attach the eyeguard (or multiple eyeguards if there are multiple optical lenses) to an optical device using the device piece 16. When no external force is applied to the eyeguard, it is in a first configuration, wherein the leaves 26 are in a closed arrangement and the view through the eyeguard is obscured. The first configuration is illustrated in figures 3B and 6.

When the user wishes to use the optical device, they apply the periocular portion of their face to the eyecup 18 and apply a force towards the optical device. The size of force required will depend upon the specific design of the eyeguard 10 and the stiffness of the biasing member 46. The force required can be set such that use of the eyeguard for long period of time does not cause discomfort to the user. The eyepiece 12 moves along the first axis relative to the device piece 16, in response to the user applying a force to the eyecup 18. The rotational ly-fixed protrusions 48 on the rim of the orifice (supported by the funnel section 42) of the eyepiece 12 interacts with the helical slot 50 of the driver 30 and the driver 30 is forced to rotate about the first axis within the eyeguard 10.

The device piece 16 is also constrained such that it cannot rotate relative to the eyepiece 12 and so the driver 30 rotates relative to the device piece 16, within the device piece 16. The rotation of the driver 30 relative to the device piece 16 causes the leaves 26 to rotate from a closed arrangement to an open arrangement as discussed with reference to figures 5 to 7. Once the leaves 26 have moved from the closed arrangement to the open arrangement, the eyeguard is in a second configuration and the user can look through the eyeguard, the view through the eyeguard no longer being obscured. The eyeguard is maintained in the second configuration by the user continuing to apply a force to the eyepiece 12 along the first axis.

When a user removes their eye from the eyeguard, and the external force along the first axis is removed, the biasing member 46 moves the eyepiece 12 away from the device piece 16, along the first axis. This moves the eyeguard from the second configuration towards the first configuration. As the eyepiece 12 moves along the first axis, the protrusion 48 moves along the slot 50, rotating the driver 30 in the opposite direction to before. The rotation of the driver 30 moves the leaves 26 back into a closed arrangement and the eyeguard is again in the first configuration. When the eye applies the external force, the above happens as the user removes their eye from the eyeguard and thus it may occur so quickly that the time between the user's eye being removed from the eyeguard and the eyeguard reaching the first configuration is negligible. If the user removes their eye from the eyeguard slowly, the eyeguard may be in the first configuration before the user entirely removes their eye. While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. Indeed, the novel methods, devices and systems described herein may be embodied in a variety of forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope of the invention defined by the claims.