TECHNICAL FIELD

The disclosure relates to a headset for wearing on the head of a user for providing augmented or mixed reality, in particular for providing a digital 3D virtual image in combination with environmental scenery.

BACKGROUND

Reality headsets can be divided into several main groups, those to be used for augmented reality (AR), those to be used for virtual reality (VR) and mixed reality (MR). VR headsets are adapted for a static experience by shutting out the surroundings, e.g. allowing the user to be completely submerged into a movie or a game. AR and MR headsets, on the other hand, must allow the surroundings to be clearly visible, providing a dynamic experience by e.g. allowing the user to move around with unrestricted vision while combining the scenery with virtual imagery.

A challenge with AR and MR headsets is that they typically require the use of see-through projection and focusing elements for generating near-eye -virtual images. Since the virtual image is located between the eye and environment scenery it needs to have a very high brightness to work against bright ambient light. Additionally, the illumination losses coming from the optical system require a source display to have natively high brightness. For higher contrast, sun shading sheets, blocking a major portion of the ambient light are used, though at the expense of deteriorating the colours (colour depth) of the scenery image. Virtual image formulation requires optical elements to be generated between the eye and scenery. Known solutions involve beam splitters which cause a significant illumination drop from the source display screen, thus requiring a source display screen with high native brightness capability. This results in issues with high-power consumption, short operating lifetime and thermal issues. SUMMARY

It is an object to provide a headset that overcomes or at least reduces the problem mentioned above.

The foregoing and other objects are achieved by the features of the independent claims. Further implementation forms are apparent from the dependent claims, the description and the figures.

According to a first aspect, there is provided a headset for wearing on the head of a user, the headset comprising: a holder for accommodating a display screen, a first, partially transparent reflective element disposed between the holder and eyes of the user, and a second reflective element, the first reflective element and the second reflective element being arranged to reflect a scenery image into the eyes of the user.

For example the second reflective element may be a mirror or a prism or a combination thereof placed in a position with respect to the first reflective element, so that the incoming light from a scenery, e.g. real, image is deflected by the second reflective element to the first reflective element and from the first reflective element to the eyes of the user. In this manner a real world image can be deflected to the eyes of a user even though a direct light path from the scenery image to the eyes of the user is obstructed by an object, i.e. a source of a virtual image, placed in front of the eyes of the user. In the present disclosure a scenery image is used to indicate a real (real world) image in contrast to a virtual image generated by a user device, such as a smartphone or the like.

The first reflective element may for instance be a semi-transparent mirror or a prism or a combination thereof. The first reflective element may thus reflect light coming from the second reflective mirror and deflect it towards the user’s eyes. Light coming from a display of a user device passes through the first reflective element towards the user’s eyes. In this manner the virtual image generated by the user device and the light from the image scenery are overlapped. In a possible implementation form of the first aspect is configured to allow a virtual image on the display to be sub-imposed on the scenery image reflected into the eyes of the user by the first reflective element and the second reflective element. In other words the virtual image on the display and the scenery image overlap to create a composite image or Augmented or Mixed image.

In a possible implementation form of the first aspect the headset comprises an optical element disposed between the holder and the first reflective element for focusing the eyes of the user onto the display screen for viewing the virtual image.

The optical element may be a focusing lens.

In a possible implementation form of the first aspect the first reflective element is arranged at an angle with the line of view of the user to the holder.

In a possible implementation form of the first aspect the second reflective element is arranged substantially parallel with the first reflective element.

In a possible implementation form of the first aspect the second reflective element is disposed above or under the first reflective element relative to the line of view of the user to the holder.

In a possible implementation form of the first aspect the second reflective element is disposed outside the line of sight from the eyes of the user to the holder.

In a possible implementation form of the first aspect the holder has a first main plane facing the eyes of the user, and wherein the first reflective element has a second main plane that is angled relative to the viewing axis from the eyes of the user to the holder. In a possible implementation form of the first aspect the headset comprises a frame connected to head attachment means and configured to support the holder, the first reflective element and the second reflective element.

In a possible implementation form of the first aspect the headset is configured to position the holder in front of the eyes of the user.

In a possible implementation form of the first aspect the first effective element comprises a pair of partially transparent reflective elements disposed between the holder and eyes of the user, the second effective element comprises a pair of second reflective elements, and wherein the pair of first reflective elements and the pair of second reflective elements are arranged to reflect a scenery image into each eye of the user.

In a possible implementation form of the first aspect at least one of the reflective elements comprises a mirror.

In a possible implementation form of the first aspect at least one of the reflective elements comprises a prism.

These and other aspects will be apparent from and the embodiment(s) described below.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed portion of the present disclosure, the aspects, embodiments and implementations will be explained in more detail with reference to the example embodiments shown in the drawings, in which: Fig. 1 is a diagrammatic representation of an optical principle used,

Fig. 2 is a diagrammatic representation of an embodiment of a headset, without its frame and head attachment means,

Fig. 3 is the diagrammatic representation of Fig. 2 including a diagrammatic representation of the optical principle used,

Fig. 4, is a diagrammatic representation of the headset of Fig. 2 including its frame and head attachment means, and

Fig. 5 is a side view of a headset according to another embodiment, including a diagrammatic representation of the optical principle used.

DETAILED DESCRIPTION

Figs. 1 to 3 illustrate a diagrammatic representation of an optical principle used by the headset 1. A scenery image is reflected into the user’s eyes by a first effective element 4, such as e.g. a semitransparent mirror. The first reflective element is angled relative to the line of sight of the user such that it allows an image, e.g. a virtual image on a display screen, in the line of sight behind the first reflective element 4 to be seen by the user. An electronic device 8, such as e.g. a smart phone with a display screen 7 is arranged in front of the eyes of the user with the first reflective element 4 between the display screen 7 and the eyes of the user. An optical element 9, such as e.g. a pair of lenses may be arranged between the display screen 7 and the first reflective element 4 in order to allow relaxed viewing of the relatively short distanced display screen 7. A second reflective element 5, such as e.g. a mirror is arranged above (as shown) or under (not shown) the first reflective element 4 in order to reflect a scenery image into the user’s eyes even though the display screen 7 or electronic device 8 is obstructing the user’s direct view to the scenery.

As shown in Fig. 3 the first reflective element 4 and the second reflective element 5 are arranged so as to effectively achieve a periscope effect that allows the user to view the scenery image that is actually blocked from direct view for the user by the electronic device 8. Instead of mirrors, the periscope effect can in an embodiment also be obtained by using e.g. prisms for the first reflective element 4 and for the second reflective element 5. In yet another embodiment the periscope effect is obtained by a combination of mirrors and prisms.

Fig. 4 shows and embodiment of a headset for wearing on the head of a user for providing mixed reality (MR) or augmented reality (AR) 1. The headset 1 has a frame 2, a holder 3, a first, partially transparent reflective element 4 disposed between the holder 3 (shown in Fig. 5) and eyes of the user, a second reflective element 5 and head attachment means 10. The headset 1 according to this embodiment has a construction similar to that of goggles.

The head-attachment means 10 may comprise a strap extending around the user’s head, along the sides. The strap could be an adjustable two-part, e.g. plastic or leather side strap comprising locking means for adjusting the length of the strap, or beer l-part elastic side strap, expanding as much as necessary when donned over the head of the user.

The frame 2, is connected to the head-attachment means 10 such that the frame 2 extends, partially or completely, in front of the face of the user when the headset 1 is worn by the user. The frame 2 may comprise only a front piece, similar to pair of goggles, or may also be provided with temples, such as those of a pair of eyeglasses. Regardless, the frame 2 is preferably adapted for resting on the head of the user, e.g. on the nasal bridge.

The frame supports the first reflective element 4 and the second reflective element 5. The first reflective element 4 and the second reflective element 5 are arranged to reflect a scenery image into the eyes of the user, in an arrangement like a periscope, as shown in Fig. 3. By using the first reflective element 4 and a second reflective element 5 that are sufficiently wide for covering both eyes of the user, the user sees a 3D scenery image. In another embodiment, the headset 1 is provided with a pair of, preferably substantially identical, first reflective elements and a pair of, preferably substantially identical, second reflective elements spaced such that these pairs of reflective elements cover both eyes of the user thereby ensuring that the user sees a 3D scenery image. The pair of first reflective elements and the pair of second reflective elements being arranged to reflect a scenery image into each eye of the user in order to achieve a 3D effect. The frame 2 also supports the holder 3. The holder 3 is configured for accommodating a display screen 7, for example a display screen of an electronic device 8, such as e.g. a smart phone. The headset 1 is configured to position the holder 3 in front of the eyes of the user when the headset 1 is worn by the user.

The holder 3 is in an embodiment configured for holding the electronic device 8, whilst keeping the display screen 7 visually uninhibited. The holder 3 may comprise a plate like member, abutting and supporting the back of the electronic device 8. The plate member being provided with holding elements such as e.g. a L-shaped brackets for releasably holding the electronic device 8. Further, the holder 3 may be a hollow frame, the frame extending at least partially around the peripheral edge of the electronic device 8, such that the display the display screen 7 remains visually uninhibited. The holder 3 may comprise brackets or clamps accommodating, supporting and interlocking with the electronic device 8 at specific locations along the edge of the electronic device 8.

A virtual image on the display screen 7 is visible to the user through the first partially reflective element 4, thereby

sub-imposing the virtual image on the scenery image reflected into the eyes of the user by the first reflective element 4 and the second reflective element 5.

In an embodiment, the headset 1 is provided with an optical element 9 disposed between the holder 3 and the first reflective element 4 for focusing the eyes of the user onto the display screen 7 for relaxed viewing of the virtual image the relatively short distance display screen 7. The optical element 9 comprises in an embodiment a focusing lens 9 or a pair of focusing lenses 9, one for each eye of the user, such as e.g. magnifying lenses.

In an embodiment, wherein the first reflective element 4 is arranged at an angle with the line of view of the user to the holder 3 / display screen 7. The angle of the first reflective element 4 in combination with the first reflective element 4 being semi-transparent allows for the scenery image to be reflected by the first reflective element 4 and for the virtual image to be seen through the first reflective element 4 (when an electronic device 8 is accommodated in the holder 3 and shows a virtual image on the display screen 7).

The first reflective element 4 can in an embodiment be provided with a thin layer of metal such as silver or aluminum.

The second reflective element 5 is preferably arranged substantially parallel with the first reflective element 4 to avoid the use of compensating optical elements.

In an embodiment the second reflective element 5 is disposed above first reflective element 4, relative to the line of view of the user to the holder 3. In another embodiment the second reflective element 5 is disposed below the first reflective element 4, relative to the line of view of the user to the holder 3.

The second reflective element 5 is disposed outside the line of sight from the eyes of the user to the holder 3.

Fig. 5 shows another embodiment of the headset 1, with its frame 2, first reflective element 4, second reflective element 5, holder 3, an optical element 9. The headset 1 is shown without its head attachment means, but it is understood that any suitable head attachment means can be used with this embodiment. The angle a between the plane of the first reflective element 4 and the line of view from the holder 3 towards the user is also shown in Fig. 5. An electronic device 8 (fine dashed lines) with its display screen 7 is shown inside the holder 3. The path of the light from the scenery through the second effective element 5 and the first effective element 4 to the eyes of the user is illustrated by a first interrupted line. The path of the light from the virtual image to the eyes of the user through the first effective element 4 is shown by a second interrupted line with dashes and dots. The frame 2 can be formed by relatively narrow elements that do not block the light on the scenery to the user decides, by either placing the frame members centrally or peripherally. In an embodiment the holder 3 has a first main plane facing the eyes of the user when the headset 1 is on the head of the user, and the first reflective element 4 has a second main plane that is angled relative to the viewing axis from the eyes of the user to the holder 3 in order to take advantage of the semi-reflective properties of the first reflective element 4 so that an image on the display screen 7 can be seen through the first reflective element 4 and image of scenery is reflected by the first effective element 4 into the user’s eyes.

In an embodiment, the first reflective element 4 comprises a semi-transparent mirror 4 or a pair of semitransparent mirrors. In another embodiment the first reflective element 4 comprises a prism or a pair of prisms.

In an embodiment, the second reflective element 5 comprises a mirror 5 or a pair of mirrors. In another embodiment the second reflective element 5 comprises a prism or a pair of prisms.

The various aspects and implementations has been described in conjunction with various embodiments herein. However, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed subject-matter, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word“comprising” does not exclude other elements or steps, and the indefinite article“a” or“an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.

The reference signs used in the claims shall not be construed as limiting the scope.