Viewing Equipment

Abstract

A headset for use as part of an Augmented Reality apparatus comprises a headband arranged to secure the headset to a user's head; and a mount connected to the headband and arranged to detachably receive a display device in a position arranged to be in front of a user's eyes in use. The headset is arranged, insofar as possible, not to block a user's peripheral vision. The mount may comprise a pair of arms arranged to support the display device. The headset may comprise a pair of lenses connected to the headband and arranged to be located between the user's eyes and the display device, wherein the lenses are double convex lenses with a flat lower edge, the flat lower edge of each lens being arranged to fall on a plane extending between a user's expected pupil location and a lower edge of the mount. The mount may be transparent.

Claims

1. A headset for use as part of an Augmented Reality or Virtual Reality apparatus, the headset comprising: a headband arranged to secure the headset to a user's head; and a mount connected to the headband and comprising a pair of arms, each arm being connected to a respective side of the headband and comprising a holder arranged to detachably receive a display device in a position arranged to be in front of a user's eyes in use; and wherein the headset is arranged not to block a user's peripheral vision.

2. The headset of claim 1, wherein the mount is arranged to receive a display device which comprises a smartphone.

3. The headset of claim 1, wherein the mount is at least substantially transparent.

4. The headset of claim 1, each holder is arranged to support a lower edge of the display device in use, such that the lower edge of the display device remains at the same level irrespective of device dimensions.

5. The headset of claim 4, wherein the arms are resiliently biased towards each other, such that display devices of varying widths may be accommodated therebetween and held in a central position.

6. The headset of claim 4, wherein the headband is arranged, in use, to encircle a user's head at an angle to the horizontal, such that the headband passes above a user's eyes, and around the back of a user's head at a level lower than the user's eyes, and wherein the arms are arranged such that a screen of the display device is at least substantially vertical in use.

7. The headset of claim 1, wherein the mount is arranged to be slideable along the headband.

8. The headset of claim 1, further comprising at least one connector connected to the headband and arranged to hold a lens between the user's eyes and the display device.

9. The headset of claim 8, wherein the at least one connector is arranged to have the lens removably connected thereto, such that the lens can be replaced.

10. (canceled)

11. The headset of claim 8, wherein the at least one connector is arranged such that there is no frame around a lower edge of a lens received thereon.

12. The headset of claim 1, further comprising a pair of lenses mounted thereon, the lenses being arranged to lie between the user's eyes and the display device in use.

13. The headset of claim 12, wherein the lenses are double convex lenses arranged to reduce a user's view of at least one edge of a display device mounted on the headset, so restricting a user's view to a digital display of the display device and the user's peripheral vision with minimal interruption therebetween.

14. The headset of claim 12, wherein a lower edge of each lens is flat, the flat edge being arranged to fall on a plane extending between a user's expected pupil location and a lower edge of the mount.

15. A headset for use as part of an Augmented Reality or Virtual Reality apparatus, the headset comprising: a headband arranged to secure the headset to a user's head; a mount connected to the headband and arranged to detachably receive a display device in front of a user's eyes; and a pair of lenses connected to the headband and arranged to be located between the user's eyes and the display device in use, and wherein the lenses are double convex lenses with a flat lower edge, the flat lower edge of each lens being arranged to fall on a plane extending between a user's expected pupil location and a lower edge of the mount.

16-19. (canceled)

20. A viewing device for use as part of an Augmented Reality or Virtual Reality apparatus, the viewing device comprising: a support; two lenses, each lens being a double convex lens with a flat lower edge, and being connected to the support; and a display device holder, the display device holder being connected to the support and arranged to engagingly receive a display device such that a lower edge of the display device is held in a predetermined position relative to the lenses, and such that the display device is arranged to be viewed through the lenses in use.

21. The viewing device of claim 20, wherein the flat lower edge of each lens is arranged to lie on a plane extending between a user's expected pupil location and the predetermined position of the lower edge of the display device.

22. The viewing device of claim 20, wherein the display device holder has a lower surface arranged to support a lower edge of a display device in use, and wherein the flat lower edge of each lens is arranged to lie on a plane extending between a user's expected pupil location and the lower surface of the display device holder.

23. The viewing device of claim 20, wherein the support comprises a headset, the headset being arranged to hold the lenses in a set position in front of a user's eyes in use.

24. (canceled)

25. The viewing device of claim 20, wherein the support is arranged to clip to the display device, and the viewing device is arranged to be manually held in place in use by a user holding the display device.

26. The viewing device of claim 20, wherein the lenses are frameless along at least their flat lower edges.

27. (canceled)

Description

[0075] There now follows by way of example only a detailed description of embodiments of the present invention with reference to the accompanying drawings in which:

[0076] FIG. 1 shows a perspective view of a headset of an embodiment;

[0077] FIG. 2 shows a plan view of the headset of FIG. 1;

[0078] FIG. 3 shows a side view of the headset of FIG. 1;

[0079] FIG. 4 shows a front view of the headset of FIG. 1;

[0080] FIG. 5 shows the headset side view of FIG. 3 with various dimensions marked;

[0081] FIG. 6 shows a plan view of a lens, the lens optionally being that shown in FIG. 1;

[0082] FIG. 7 shows a front view of the lens of FIG. 6;

[0083] FIG. 8 shows a side view of the lens of FIG. 6;

[0084] FIG. 9 shows the lens views of FIGS. 6 to 8 with various dimensions marked; and

[0085] FIG. 10 shows a plan view of the headset of FIG. 1 alongside a cross-sectional view of a marked arm portion.

[0086] In the figures, like or corresponding reference numerals are used for like or corresponding features.

[0087] FIG. 1 illustrates a viewing device 100, and in particular a headset 100, of an embodiment. The headset 100 is arranged to be worn on a user's head, and comprises a headband 102 arranged to secure the headset 100 to the user's head in use. The headband 102 may also be referred to as a strap. The headband 102 is arranged to have other components of the headset 100 connected thereto, and to support those components. The headband 102 is arranged to allow the user's head/skull to support the weight of the headset 100 and any device(s) mounted thereon.

[0088] In the embodiment shown, the headband 102 is arranged to fully encircle a user's head. In alternative embodiments, other designs may be used; for example, a band 102 around a rear part of a user's head only may be connected to a band at an angle thereto arranged to go on top of a user's head and behind the ears, not passing around the forehead, or the headband 102 may form an incomplete loop with a gap at the back, with the ends of the band resiliently biased towards each other to grip a user's head.

[0089] In the embodiment shown, the headband 102 comprises an adjustor 103 arranged to allow the headband 102 to be loosened or tightened to fit different head sizes. The adjustor 103 of the embodiment shown also comprises a support 103a, which is padded and shaped for comfort and, in this embodiment, arranged to sit behind and in contact with a user's head in use. The support 103a is wider than the headband strap and may help to distribute weight more comfortably. In the embodiment shown, the headband 102 is made of a semi-rigid, flexible polymeric material, being sufficiently rigid to hold its shape and support the weight of a display device whilst retaining sufficient flexibility for ease of fitting. In alternative embodiments, a material of at least part of the headband 102 may be elasticated or otherwise inherently adjustable such that no separate adjustor 103 may be needed to fit a range of head sizes.

[0090] An “off-the-shelf” traditional headband design may be used to provide the headband 102 of the headset 100 described herein.

[0091] The headband 102 as described herein may allow the weight to be borne directly by a user's head/skull, with little or no weight on the user's nose or ears. The skilled person would appreciate that many different headband 102 designs are possible whilst still providing a better weight distribution than would be provided by a glasses-type mounting arrangement, in which a substantial amount of weight may be supported by a user's nose and/or ears, and that the embodiment shown is described in detail by way of non-limiting example only.

[0092] For example, in alternative embodiments, the headband 102 may form a part of a hat or other headgear into which the headset 100 is incorporated.

[0093] In the embodiment shown, the headband 102 is arranged, in use, to encircle a user's head at an angle, β, to the horizontal, such that the headband passes above a user's eyes and around the back of a user's head at a level lower than the user's eyes.

[0094] The headset 100 further comprises a mount 104. The mount 104 is arranged to be connected to the headband 102 and supported thereby. In some embodiments, the mount 104 may be integral with the headband 102; in other embodiments, such as the embodiment shown, the mount 104 is a separate component mounted on the headband 102.

[0095] The mount 104 is arranged to receive a display device in a position arranged to be in front of a user's eyes in use, such that a user can view a display of the display device held by the mount 104 when wearing the headset 100. The mount 104 is arranged to hold a display device in a predetermined position with respect to the headband 102, and therefore with respect to a user's head in use.

[0096] In some embodiments, the display device may be a self-contained device such as a smartphone. In other embodiments, the display device may be a component of a larger device; for example a screen connected to a separate processor and/or power source. It will be appreciated that, in many embodiments, self-contained devices may be preferred to avoid any restriction on a user's movement due to cables or the like. In other embodiments, a separate screen may be preferred, for example to reduce display device weight.

[0097] The display device may be a smartphone and the display of the display device may be a smartphone screen.

[0098] Unlike prior art headsets which deliberately enclose a user's eyes and the display device, the headset 100 of the embodiments being described is arranged not to block a user's peripheral vision. Interference with a user's field of view is minimised by the headset design, whilst still allowing a display device to be held in front of a user's face. Various factors may be used to accomplish this, including one or more of the below: [0099] headset shape, in particular shape of the mount 104; [0100] headset material choices, in particular materials for the mount 104; and [0101] lens design (described below).

[0102] In the embodiment being described, the headset mount 104 is made of an at least substantially transparent material, so as not to block a user's field of view—the user may be able to at least partially see through the mount 104. For example, in the embodiment being described a transparent polymeric material (and more specifically transparent polypropylene) is used for all components of the mount 104. The mount 104 is therefore at least substantially transparent.

[0103] In the embodiment being described, the headset mount 104 comprises a framework of relatively narrow arms and/or struts 105, 106, so as to reduce or minimise the area around a user's eyes occupied by a headset component. Each strut 105, 106 may have a width (parallel to the surface of a user's head) of no more than 2 cm, optionally of no more than 1.5 cm, and further optionally of no more than 1 cm. Each strut 105, 106 may have a thickness (perpendicular to the surface of a user's head) of no more than 1 cm, optionally of no more than 0.5 cm, and further optionally of no more than 0.3 cm. The use of relatively thin struts 105, 106, preferably made of a lightweight but sufficiently rigid polymeric material, may reduce or avoid possible obstruction to a user's peripheral vision.

[0104] In some embodiments, a top cover may be provided (optionally arranged to detachably clip to the mount 104) so as to block light entering from above. This may reduce glare in some scenarios, whilst not impeding a user's peripheral vision to the sides of and below the display device. In some embodiments, detachable covers may be provided for the sides and underneath of the display device—these covers may clip to the mount 104, and may impede or fully block peripheral vision. The headset 100 may therefore be used in a “fully enclosed” mode, more akin to prior art VR headsets—the headset and removable covers approach described herein allows a single device 100 to offer both maximum peripheral view and fully immersive VR experiences, with perhaps options in between (e.g. top cover only). The headset 100, and more specifically the mount 104, may therefore comprise one or more attachment means (e.g. clips) arranged to allow one or more covers to be attached thereto.

[0105] In particular, in the embodiment being described the mount 104 comprises a pair of arms 106. Each arm 106 is connected to the headband 102 on a respective side of the headband 102 (and therefore of a user's head/face in use), near a front of the headband, and extends forward and downward therefrom. Each arm 106 comprises a holder 108 arranged to receive one side of a display device, such that the display device is engagingly received therebetween. Each holder 108 may therefore be referred to as a display device holder. Each holder 108 may be designed to be able to hold the display device by itself (so providing some redundancy and additional security), or each may provide some support such that the pair of holders 108 together can hold the device in place securely.

[0106] In the embodiment shown, each arm 106 is biased or sprung so as to urge the ends of the arms 106 comprising holders 108 towards each other, for example with a natural, unstressed, spacing being slightly smaller than the expected minimum width of a display device mounted therebetween. The arms 106 may therefore each exert an inward force on a display device, improving grip and/or accurately (horizontally) centring the display device with respect to the headset 100, and therefore with respect to a user's intended field of view in use. This flexibility may allow a variety of display devices of different widths to be received by the same mount 104, in at least substantially the same position. The biased arms 106 of the present embodiment may therefore be described as “live hinged”, with a flexible portion of the same material providing biasing between more rigid regions of the same material. A separate biasing member such as a spring may be used in some embodiments. The arms 106 may not be biased in other embodiments.

[0107] The arms 106 extend at an angle to the headband 102 and are at least substantially straight from where they leave the headband 102 to a position on the mount 104 arranged to receive a lower edge of a display device (e.g. a smartphone); the arms 106 may therefore each be described as following a straight trajectory from the headband 102 to the base of the respective holder 108.

[0108] In the embodiment shown, the arms 106 extend at an angle to the headband 102, and the holders 108 extend at an angle to the rest of the arms 106, such that a screen of a display device held by the arms is at least substantially vertical. In particular, an angle, a, between the headband 102 and a surface of the holder 108 arranged to receive lower edge of the display device may be selected accordingly, bearing in mind an intended angle, β, of the headband 102 with respect to the horizontal.

[0109] It will be appreciated that the surface of the holder 108 arranged to receive the lower edge of the display device remains in its intended vertical position (within relatively small bounds) even when the holders 108 are pushed apart to insert a wider display device therebetween—further, even if a taller display device extends further upwards out of the open top of the holders 108, the lower edge of the display device remains at the same level irrespective of device dimensions. In embodiments in which the device extends outwards beyond the holders 108, the lower edge of the display device likewise remains at the same level irrespective of device dimensions. The angle from lenses 200 (described below) to that lower edge therefore remains at least substantially constant for all headset-compatible display devices—the headset 100 may therefore be arranged to hold the display device such that at least a lower edge of the display device is in a predetermined position with respect to the headset 100, and in particular with respect to the lenses 200.

[0110] In the embodiment shown, the angle, β, of the headband 102 with respect to the horizontal is intended to be somewhere between 6° and 46°, and optionally around 26°, with the headband 102 being lower behind a user's head than near a user's face. A position in this range has generally been found to provide a comfortable fit for a variety of skull shapes—with the back of the strap 102 below the head “bump” at the back of the skull and the front higher up on the forehead where the skull begins to curve backwards; this may prevent the weight of the display device from pulling the headset 100 downwards in use.

[0111] The angle, a, between the headband 102 and the arm 106, and more specifically from the headband 102 to a surface of the holder 108 arranged to receive a lower edge of the display device, along the arm, may be selected to be in the range from 95° to 135°, and optionally around 115°, accordingly. A user may then be advised to adjust the headband 102 such that a screen of the display device is vertical to get an appropriate angle for the headband 102. The surface of the holder 108 arranged to receive the lower edge of the display device may be arranged to be horizontal in use.

[0112] In various embodiments, the mount 104 is moveably mounted on the headband 102, and optionally slidably mounted thereon. In the embodiment shown, the mount 104 comprises a pair of slider portions 104a which are parallel to the headband 102 and slid ably mounted on the headband 102. The slider portions 104a may be mounted in a ratchet-type arrangement to allow a user to slide the mount 104 through a set of discrete positions—e.g. forward and backward from a user perspective—to select an appropriate fit. Each arm 106 extends at an angle from a respective slider portion 104a. In alternative embodiments, the arms 106 may be mounted to the headband 102 in a fixed position.

[0113] In the embodiment shown, each holder 108 is substantially tubular in shape, with a closed lower end (or base) 108a to the tube, and a cut-away portion along the length of the tube providing a lateral opening. The lateral openings of the pair of holders 108 are aligned with each other, and facing each other (and may therefore be described as inwardly-directed), so that opposing edges of a display device may be respectively received in each. In the embodiment shown, the holders 108 are arranged to be at least substantially vertical when the user is standing straight, and the closed lower end of each tube may support a lower edge of the display device at/near a corner thereof.

[0114] In the embodiment shown, the forward region of the front surface of each holder 108 is cut away from the closed base 108a, and resiliently biased into its tubular shape. This may facilitate inserting an edge of a display device into the lateral opening, and the flexibility and biasing may allow display devices of a variety of thicknesses to be received within the same holder 108. In particular, the forward region of the front surface each holder 108 has a vertical lip 108b, angled so as to be curled away from the tubular shape of the holder 108 and arranged to facilitate inserting an edge of a device into the lateral opening.

[0115] In the embodiment shown, the holder 108 is only approximately tubular in shape, having a flattened side in the region arranged to be closest to a user's face, the flattened side being arranged to rest against a front/screen side of the display device in use, so keeping an at least approximately constant horizontal distance, X, between a plane of the screen and a plane of the mount 104 (in particular, a plane of lenses mounted on the mount in the embodiment shown). It will be appreciated that the arms 106 flexing outwards for a wider display device, or moving further inward for a narrower device, may move the device location away from the lens 200, or towards the lens 200, respectively, by a relatively small amount. The vertical lip 108b may be arranged to rest on, and grip, a rear surface of the display device, opposite the screen.

[0116] In other embodiments, different holder designs may be used from that shown, whilst still comprising a surface of the holder 108 arranged to receive the lower edge of the display device so that the device remains in its intended vertical position. In some such alternative embodiments, the holders 108 mounted on the arms 106 may be described as clips, gripping the display device from underneath (the device may be inserted from above). As compared to the holders 108 shown in the Figures, in which the arms 106 may be live-hinged so as to always contact the outer edges/sides, and particularly the outside bottom corners, of display devices of varying sizes, the holders 108 of other embodiments may be located a fixed distance apart, and the corners of a display device may extend beyond the holders 108, by an extent depending on display device size. More rigid, non-live-hinged, arms 106 with holders 108 clipping around the lower edge of the device may allow more secure and straightforward mounting in some embodiments, and the distance between the lenses 200 and the device screen may be more precisely fixed regardless of device size (it will be appreciated that, with live hinges, wider devices may be positioned slightly closer to the lenses 200 than narrower ones as the arms 106 flex, which may provide small variations in focus). In such embodiments, it will be appreciated that the holders 108 are still generally arranged to be at or near a side edge of the display device, to minimise or avoid occlusion of the display (and in particular of the relevant area of the display, as described below). All or part of the holders 108 may be transparent in some embodiments, which may further reduce occlusion. Whereas the holders 108 shown in the Figures provide inwardly-directed openings facing each other with a solid outer surface, other holders may therefore have upward-facing openings and no solid outer edge surface. It will be appreciated that any suitable grip design known in the art may be used, and that the scope of the invention is not limited by holder type.

[0117] The design and positioning of the lenses 200 may result in an almost-circular area of a screen of the device being visible in each eye. This area may have a fixed size and position regardless of the device dimensions. The grips/holders 108 are therefore designed to fall outside of that visible area (towards the sides/edges of the device), but may be located inwardly from the device edges without occluding that visible area.

[0118] In the embodiments described herein, the ends of the arms 106 are unconnected to each other when the display device is not between them. It will be appreciated that this open structure is a marked departure from prior art designs which generally have a box or goggles surrounding and covering a significant portion of the user's face. The headset 100 as described herein moves away from the idea of having an enclosed frame (with or without any “windows”), instead providing an entirely redesigned product which keeps as much peripheral vision open as possible. In the embodiment shown, the holders 108 are designed to receive a substantially cuboid display device which is much wider and taller than it is thick—as this is a standard shape for current smartphones and tablets. Differing holder designs may be used as appropriate in embodiments arranged to receive differently shaped display devices.

[0119] In the embodiment shown, the arms 106 are interconnected so as to form a single piece mount 104. In alternative embodiments, the arms 106 may be separate, and each individually mounted on the headband 102. The interconnection may improve rigidity and/or accuracy of screen positioning.

[0120] In the embodiment being described, the mount 104 further comprises a strut 105 extending between the arms 106 and connecting them together. The strut 105, which may be referred to as a cross piece, as it extends across a portion of the headset 100, extends at least substantially horizontally, and is arranged to be located above a user's eyes and adjacent a user's forehead in use, in much the same way as the upper part of the frame of a pair of glasses. The strut 105 may be arranged to rest on a user's forehead in some embodiments, and may help to support the display device/to secure a position of the headset 100 in some embodiments. The strut 105 may be arranged to be spaced forward from a user's forehead in other embodiments.

[0121] In the embodiment shown, each arm 106 has a width of around 1 cm and a thickness which varies with height, increasing from around 0.25 cm in an upper region 1002 to about 0.35 cm in a lower region 1004, as illustrated by the cross-sectional view 1000 shown in FIG. 10, taken along line A-A. The strut 105 of the embodiment being described is more rigid than the arm 106, with a thickness of around 0.5 cm of the same material.

[0122] It was determined through experimentation that, for the design and materials of the embodiment being described, a rectangular cross-section of the arms 106 led to the arms 106 splaying outwards when a display device was mounted thereon, resulting in the base 108a of the holder 108 being angled out away from the vertical in some cases, so not supporting the display device in the desired position. The cross-sectional profile 1000 shown in FIG. 10, with thickness decreasing with height, was found to reduce this splaying, so improving display device positioning. This more triangular, or trapezoidal, arm profile 1000 was found to increase flexibility along the top edge 1002 of the arm 106, especially at the connection point where the arms 106 meet the holders 108, allowing them to be more easily twisted/influenced by the display device's outer profile whilst remaining in contact with, and parallel to, the edges of the display device (e.g. a phone). By contrast, the tendency when the arms 106 were rectangular in profile was for the holders 108 to turn outward and not remain parallel or fully in safe contact with the display device edges or bottom surface. The decrease in arm thickness with height may be present in just a portion of the arm 106 near the holder 108, for example in some or all of the region of the arm 106 between the strut 105 and the holder 108 in the embodiment shown. In other embodiments, this variable-thickness profile 1000 may be present along the full length of each arm 106.

[0123] In embodiments in which the arms 106 are biased by a live hinge-type arrangement, the strut 105 may rigidify a portion of the mount/arms such that only the portion of each arm 106 between the strut 105 and the holder 108 bends in use, as a display device is inserted or removed.

[0124] In the embodiment shown, the strut 105 extends forwardly from each arm 106, and at an angle thereto so as to allow the strut 105 to be at least substantially horizontal, and then curves towards the other arm 106 (through an angle of around 90° in the embodiment shown), with a straight portion connecting the two curved corners. A different shape, for example a more angular shape, may be used in other embodiments.

In the embodiment being described, the strut 105 comprises one or more connectors 107 arranged to hold lenses 200 between the user's eyes and the display device, such that the user can view the display of the display device through the lenses. The lenses 200 are therefore mounted to the arms 106 via the cross-piece strut 105—as a result, in embodiments in which the mount 104 is moveably mounted on the headband 102 (e.g. slidably), the lenses 200 can move with the display device. This may help to maintain correct alignment between the lenses 200 and display device as compared to mounting the lenses 200 separately to the headband 102. As the mount 104, and therefore the arms 106, are adjustable with respect to the headband 102 in such embodiments, adjustment for different head shapes is facilitated—having the lenses 200 mounted on the arms 106 maintains a constant lens to device screen distance, the distance being kept at the appropriate constant value for correct focus (that distance is generally found to be more important to be fixed than the eye to lens distance).

[0125] In alternative embodiments, one or more connectors 107 for lenses 200 may be connected to the headband 102 directly/not via the same mount 104 as used to support a display device.

[0126] In the embodiment being described, the one or more connectors 107 are arranged to have the lenses 200 removably connected thereto, such that lenses 200 can be replaced, e.g. if damaged, or to accommodate a user's prescription or a visual choice. In alternative embodiments, the lenses 200 may be permanently connected to the headset 100, and/or may be integral with the connectors 107, for example being made of the same, optionally polymeric, material. In various embodiments, the one or more connectors 107 are also made of a transparent material. Generally, the transparent material may be colourless, however, in some embodiments, a coloured or tinted lens may be used.

[0127] The lenses 200 are connected to the headset 100 in such a way that there is no part of the connector or other frame along a lower edge of the lenses 200—the lenses 200 may therefore be described as being rimless or frameless along at least their lower edges.

[0128] In some embodiments, a lens 200 of a known kind may be used, such as those described in the Google Cardboard technical specifications (available here: https://arvr.google.com/intl/en_uk/cardboard/manufacturers/). However, an improved lens design found to reduce interference with a user's peripheral vision, as described below, is used in various embodiments.

[0129] In the embodiment being described, two lenses 200 made of optical grade PMMA (Poly(Methyl MethAcrylate)) are detachably connected to a connector 107.

[0130] In the embodiment shown, each lens 200 is connected to a separate portion 107a, 107b of the connector 107; these separate portions 107a, 107b are slidably mounted on a joining portion of the connector 107 such that a spacing between the lenses 200 can be adjusted. This may allow for adjustment for a specific user's inter-pupillary distance, and/or may provide improved fit across a variety of face shapes. This use of two separate, relatively-moveable, connection portions may alternatively be described as the headset 100 comprising a pair of connectors 107a, 107b.

[0131] In this embodiment each connector portion 107a, 107b is arranged to hold an inner edge of the respective lens 200 (i.e. an edge arranged to be nearest a user's nose in use). The connector portion 107a, 107b is arranged to grip only this inner edge of the lens 200 in some embodiments; in other embodiments, the connector portion 107a, 107b may be arranged to grip an upper edge of each lens 200 in addition (or instead), and/or the outer edge.

[0132] In the embodiment shown, each lens 200 has an optical portion 202, through which light is transmitted to a user, and a joining portion 204, arranged to facilitate connecting the lens 200 to the connector. In the embodiment shown, the joining portion 204 comprises two shaped protrusions, or tabs, arranged to be received and gripped within respective sockets in the corresponding portion of the connector 170. In the embodiment shown, each tab extends by a distance, T, of 3 to 4 mm, and optionally of around 3.95 mm, on the side of the lens arranged to be nearest a user's nose in use. The skilled person will appreciate that many different connector designs are possible and that this example is not intended to be limiting.

[0133] The lenses 200 may be arranged to reduce a user's view of one or more edges of a display device mounted on the headset 100, so restricting a user's view to a digital display of the display device and the user's peripheral vision with minimal interruption therebetween, providing a more seamless visual transition. The lenses 200 may be arranged such that peripheral vision is maintained as much as possible without the display device becoming visible outside/around the lens.

[0134] In the embodiment shown, each lens 200 is a double convex lens. Optical properties of the lenses may be selected in line with other lenses used in the field of AR and VR applications; for example, 34 mm diameter aspherical singlet lenses with an 80° field of View may be used as described for Google® Cardboard (I/O 2015 edition). Various effective diameters and other dimensions are visually indicated in FIG. 9, although it will be understood that these lens images are provided by way of example only, and that lens curvature may also be adjusted depending on the refractive index of the chosen lens material, the chosen eye-display device spacing (and/or lens-display device spacing, X, as marked in FIG. 5), and other factors known to one skilled in the art. The precise lens shape shown in FIG. 9 is therefore not intended to be limiting.

[0135] Unlike other lenses used in the field, however, the lenses 200 of the embodiment being described are “cut away” so as to have a flat, horizontal, lower edge, instead of the more traditional circular or oval shape. It will be appreciated that the term “cut-away” is used for illustrative purposes only and is not intended as a comment on manufacturing processes—the lens 200 may be moulded to the desired shape without any part thereof needing to be removed.

[0136] In the embodiment shown, each lens 200 has a maximum width (in the horizontal direction) of around 34 mm. The lens 200 may be substantially circular in front view, but with a cut-away portion providing a flat lower edge. In the embodiment shown, the flat lower edge has a length, L, of around 19 mm. The lens 200 may have a maximum height, H, of around 25-30 mm. These dimensions may vary in other embodiments.

[0137] In the embodiment shown, each lens 200 is a double convex lens, having a first convex surface 206 adjacent a user's eye and a second convex surface 208, optionally of a different curvature, on the opposing side. In the embodiment shown, the surface 206 facing the user's eye in use is less convex than the surface 208 facing away from the user's eye. The curvatures may vary in other embodiments. The edges of each lens 200 have a non-negligible width, which may facilitate mounting of the lenses 200. The curved surfaces therefore do not meet at a point in the embodiment shown, but rather have a flat lens edge therebetween. In the embodiment shown, the flat portion between the curved surfaces has a thickness of around 1.4 mm, and the lens 200 has a maximum total width of around 8.8 mm, including that flat portion. These dimensions may vary in other embodiments.

[0138] Each lens 200 is arranged such that its flat lower edge is arranged to fall on a plane extending between a user's expected pupil locations and a lower surface 108a of the mount 104 arranged to receive the display device—the lower surface 108a of the mount is generally at least substantially level with a lower edge of a screen of the display device in use. Each lens 200 is therefore arranged such that its flat lower edge falls on a plane extending between a user's expected pupil locations and a predetermined intended position of the lower edge of the display device/screen.

[0139] In the embodiment shown, the connectors 107 and mount 104 are arranged such that a spacing, X, between a (vertical) centre line of the lens 200 and an intended location of a screen of the display device (as defined by the arms 106 and holders 108) is in the range from 26 to 46 mm (inclusive), and optionally is equal to or around 36 mm.

[0140] In the embodiment shown, the upper edge of each lens 200 is also flattened, optionally for ease of fit with the connector 107—this may vary in other embodiments.

[0141] In some embodiments, lenses 200 designed and located as described herein may be used with headsets 100 which are arranged to significantly block a user's peripheral vision (e.g. for fully-enclosed headsets used for a completely virtual experience), but they may be of particular utility with headsets 100 arranged to provide good peripheral vision, disguising the rim of the display device and providing a more seamless transition. The cut away portion may provide maximum direct vision of the real world on the lower surface of the display, and a more apparently straight transition between the two views (real and virtual/augmented). For example, a user's view of a lower edge of a frame, surround, or cover of a display device, and/or of one or more controls of the display device may be obscured from view due to the design of the lens 200 and its position relative to the display device, so providing a more immersive experience. Even for display devices such as bezel-less or “edgeless” smartphones, where a screen extends the full width and/or height of the device, the lens 200 may still help to provide a smoother apparent transition, without such a noticeable boundary at the edge of the display device. In some implementations, detachable covers may be provided which clip (or otherwise fit) onto a headset 100 as described herein, so as to allow a user's peripheral vision to be blocked for an immersive VR experience. The same hardware 100 may therefore have increased utility by allowing unimpeded peripheral vision in AR scenarios and enclosed vision in VR scenarios.

[0142] Further, in the viewing devices of some embodiments, the lenses 200 with flat lower edges as described herein may be used with other supports in place of a headset 100; for example with supports arranged to hold a display device in a set position with respect to a pair of lenses 200, but to be held in position in front of a user's eyes by a user's hand, rather than being secured to a user's head. In such embodiments, the viewing device may be arranged to be held in place by a user holding the support, and/or holding the display device connected thereto (the support may be thought of as being mounted on the display device in the latter case). Similarly, in still further embodiments, a support may be provided at a fixed location—e.g. mounted on a wall—and a user may be encouraged to stand in a specific location to use the lenses 200 mounted on the support 200. In such embodiments, a display device may be permanently mounted to the support, instead of detachably connected so that a user may use a personal smartphone therewith, for example as part of a permanent installation. It will therefore be appreciated that lenses 200 designed as described herein, and arranged to be positioned as described herein with respect to a display device and a user's eyes, may be used with a wide variety of support designs, not limited to the example of a headset 100 described in detail herein. For example, the viewing device may be a minimal, handheld, fold-up viewer. It will be appreciated that a wide range of viewing devices may benefit from the neater transition between real and virtual content afforded by the flattened lens edges arranged as described herein.

[0143] A headset 100, or other viewing device, as described herein may be used for augmented reality applications, optionally providing virtual images which blend in with a user's peripheral vision so as to provide an immersive experience, with virtual elements blended with a user's real-world view. In such embodiments, the display device may be used to display a live video feed of the environment in front of the user, with overlaid (or otherwise incorporated) virtual images and/or text, so adding virtual content to the scene.