Removable lens assembly for a head-mounted display

A lens assembly can be removably attached to an eye cone of a HMD. The eye cone displays images to an eye of a user of the HMD. The eye cone includes a peripheral wall that extends towards rear of the HMD. The lens assembly includes a corrective lens and a frame. The corrective lens corrects a vision error of the eye of the user. The frame includes an inner surface onto which the corrective lens is attached. The frame also includes a wall that receives a peripheral wall of the eye cone for removably securing the lens assembly to the HMD. The HMD can include another eye cone that displays images to the other eye of the user. Another lens assembly can be removably attached to the other eye cone.

BACKGROUND

The present disclosure generally relates to head-mounted displays (HMD), and specifically to a lens assembly that can be removably inserted into HMD.

Use of HMD for virtual reality (VR) or augmented reality (AR) applications has become more commonplace. However, many users of HMD have vision errors and currently available HMD do not accommodate need of wearing prescription glasses for those users. Some users choose to wear contacts while using HMD, which impairs user experience with HMD. Some users choose to wear their prescription glasses inside HMD. But HMD do not always have enough space for the users' prescription glasses. It is possible to design HMD to have enough space between the front assembly of the HMD and the user's face to accommodate users wearing prescription glasses. However, such a design would increase the size of the HMD and can impair experience of users who do need to wear prescription glasses.

SUMMARY

Embodiments relate to a removable lens assembly for correcting one or more vision errors of a user of a HMD. The removable lens assembly can be removably attached to the corresponding eye cone of the HMD. For example, the removable lens assembly can be attached on the eye cone when vision error correction is needed and detached from the eye cone when vision error correction is not needed or to use a different prescription lens.

In some embodiments, the removable lens assembly includes a corrective lens and a frame. The corrective lens corrects one or more vision errors of the user's eye. In some embodiments, the corrective lens is a prescription lens prescribed by an ophthalmologist or an optometrist. The corrective lens can be attached onto the frame. The frame includes a wall at a front portion of the frame to which a peripheral wall of the eye cone is removably attached.

The HMD can have two eye cones for both eyes of the user, each of which receives a separate removable lens assembly. In some embodiments, the two eye cones are symmetric. Corrective lenses of the two removable lens assemblies can be different to correct different vision errors of the two eyes of the user.

The figures depict embodiments of the present disclosure for purposes of illustration only.

DETAILED DESCRIPTION

Embodiments relate to a removable lens assembly for use in a head-mounted display (HMD). The removable lens assembly includes a corrective lens and a frame. The corrective lens corrects vision error of an eye of a user of the HMD. The corrective lens can be attached at one side of the frame. The removable lens assembly can be removably attached to an eye cone of a HMD through one or more protrusions of the frame and one or more notches of the eye cone.

FIG. 1is a perspective view of a HMD100including a pair of removable lens assemblies110A and110B, in accordance with an embodiment. In the embodiment ofFIG. 1, the HMD100further includes a front rigid body120and a head strap130. The head strap130, in some embodiments, has adjustable length. Between the front rigid body120and the head strap130of the HMD100, there is sufficient space allowing a user to mount the HMD100onto the user's head. In other embodiments, the HMD100may include additional, fewer, or different components. For example, the HMD100includes eyeglasses temples and temples tips, instead of the head strap130.

The HMD100is a head-mounted display that presents media to a user comprising virtual and/or augmented views of a physical, real-world environment with computer-generated elements. Examples of the media presented by the HMD100include images (e.g., 2D or 3D images), video (e.g., 2D or 3D video), audio, or some combination thereof. Images and video can be presented to each of the eyes of the user by using electronic displays enclosed in the front rigid body120of the HMD100.

The HMD100may be part of, e.g., a VR system, an AR system, a MR (mixed reality) system, or some combination thereof. In embodiments that describe AR system and/or a MR system, portions of the HMD100that are between a front side of the HMD100and an eye of the user are at least partially transparent (e.g., a partially transparent electronic display).

The HMD100has two eye cones210(shown inFIG. 2), one for directing images generated by the front rigid body120to the user's left eye, and the other for directing images by the front rigid body120to the user's right eye. An eye cone210includes an optical lens213(shown inFIG. 2). The optical lens213is an optical element, such as an aperture, a Fresnel lens, a convex lens, a concave lens, a filter, or any other suitable optical element that affects the image light emitted from the electronic display. Moreover, the optical lens213may include combinations of different optical elements. In some embodiments, one or more of the optical elements in the optical lens213may have one or more coatings, such as partial reflectors or anti-reflective coatings.

The optical lens213can magnify light received from the corresponding electronic display. Magnification of the image light by the optical lens213allows the electronic display of the HMD100to be physically smaller, weigh less, and consume less power than larger displays. Additionally, magnification may increase a field of view of the displayed media. For example, the field of view of the displayed media is such that the displayed media is presented to cover almost the entire (e.g., 110° diagonal), and in some cases, entire instantaneous field of the user's view. In some embodiments, the effective focal length the optical lens213is larger than the spacing to the electronic display. Consequently, the optical lens213magnifies the image light projected by the electronic display. Additionally, in some embodiments, the amount of magnification may be adjusted by adding or removing optical elements.

The optical lens213may be designed to correct one or more types of optical error. Examples of optical error include: two dimensional optical errors, three dimensional optical errors, or some combination thereof. Two dimensional errors are optical aberrations that occur in two dimensions. Example types of two dimensional errors include: barrel distortion, pincushion distortion, longitudinal chromatic aberration, transverse chromatic aberration, or any other type of two-dimensional optical error. Three dimensional errors are optical errors that occur in three dimensions. Example types of three dimensional errors include spherical aberration, chromatic aberration, field curvature, astigmatism, or any other type of three-dimensional optical error. In some embodiments, content provided to the electronic display for display is pre-distorted, and the optical lens corrects the distortion when it receives image light from the electronic display generated based on the content. In some embodiments, the eye cone210also includes a ring on a surface to engage the optical lens213with the eye cone210. The ring is adhesive. Both the ring and the optical lens213can be permanently attached on the eye cone210.

The removable lens assemblies110can be removably attached to the eye cones210of the HMD100using a mechanical mechanism including, for example, protrusions and notches. For example, a removable lens assembly100is attached on a corresponding eye cone210when the protrusions snap into the notches. Also, the removable lens assembly110can be detached from the eye cone by pulling the removable lens assembly110from the eye cone210.

The removable lens assemblies110presents corrected image to corresponding eye of the user. A removable lens assembly110includes a corrective lens that corrects refractive errors in the eye of the user. The corrective lens can also prevent dusts or moisture from contaminating a surface of the corresponding optical lens.

The removable lens assembly110further includes a frame that holds the corrective lens, as described below in detail with reference toFIG. 4. The corrective lenses of the two removable lens assemblies110can have different configurations, e.g., due to different refractive errors of the two eyes of the user or for a purpose of creating three-dimensional effects. More details about those components of the removable lens assembly110are described in conjunction withFIG. 4.

FIG. 2is another perspective view of the HMD100illustrating one of the removable lens assemblies110detached from the HMD100, in accordance with an embodiment. Various components including the head strap130are not shown inFIG. 2to facilitate understanding. As shown inFIG. 2, the removable lens assembly110A is detached from its corresponding eye cone210A. Accordingly, the optical lens213A is visible. In some embodiments, a component of the HMD100behind the optical lens213A is an electronic display for the left eye of the user of the HMD100.

FIG. 3Ais a perspective view illustrating a portion of the HMD100including an eye cone210A, in accordance with an embodiment. The eye cone210A is for the left eye of a user of the HMD100and can receive the removable lens assembly110A. Although not shown inFIG. 3A, the HMD100includes another eye cone210B for the right eye of a user of the HMD100and receiving the removable lens assembly110B. In one embodiment, the eye cone210B may be symmetric to the eye cone210A but different in shape so that the removable lens assembly for one eye cone would not fit onto the other eye cone.

The eye cone210A includes the optical lens213A and a peripheral wall215that has a plurality of ribs217to provide rigidity and strength. Even thoughFIG. 3Ashows three ribs217on the right side of the peripheral wall215, the eye cone210A can have more ribs217, e.g., on the left side of the peripheral wall215.

FIG. 3Bis a side view of the eye cone210A, in accordance with one embodiment. The eye cone210A has a conical body333from which the peripheral wall215extends. On the outer surfaces of the peripheral wall215, at least one notch343is formed to secure the removable lens assembly110A to the eye cone210A. Although only one notch343is shown inFIG. 3B, a plurality of notches343may be formed around the peripheral wall215. One or more protrusions510(shown inFIG. 5) formed on the inner surface of the removable lens assembly110A snap into the one or more notches343to secure the removable lens assembly110A onto the eye cone210A. The user may push or pull the removable lens assembly110A towards or from the eye cone210A to attach or detach the removable lens assembly110A to or from the eye cone210A.

FIG. 4is an exploded view illustrating components of a removable lens assembly110, in accordance with an embodiment. As shown inFIG. 4, the removable lens assembly110includes a corrective lens410and a frame420.

The corrective lens410corrects refractive errors in vision of an eye of a user of the HMD100. For example, the corrective lens410is prescribed by an ophthalmologist or an optometrist and has a power determined by the ophthalmologist or optometrist. The corrective lens410can treat myopia, hyperopia, astigmatism, presbyopia, other types of errors in vision, or any combination thereof. Examples of the corrective lens410include single vision lens, bifocal lens, trifocal lens, varifocal lens, etc. The corrective lens410has a front surface413, a rear surface517, (shown inFIG. 5B) and a side surface415connecting the front surface413and the rear surfaces.

The corrective lens410also prevents dusts or moisture from contaminating the inner surface of the optical lens213. The corrective lens410may also perform additional optical function such as polarizing, magnifying or refracting of the light. In some embodiments, one or more of the optical elements in the corrective lens410may have one or more coatings, such as partial reflectors or anti-reflective coatings. The corrective lens410may also correct one or more types of optical error.

The frame420holds the corrective lens410at its front portion. In the embodiment ofFIG. 4, when the removable lens assembly110is attached on the corresponding eye cone210of the HMD100, the corrective lens410is closer from the user's eye and the optical lens213of the eye cone210is further to the user's eye. In some alternative embodiment, the corrective lens410can be further to the user's eye but the optical lens213can be closer from the user's eye.

The frame420further includes a wall428at its front portion surrounding the frame420. The peripheral wall215of the eye cone210is inserted through the inner surface of the wall428. The inner surface of the wall428is formed with one or more protrusions510(shown inFIGS. 5A and 5B) that snap into the one or more notches343formed on the surface of the peripheral wall215. The combination of the notches343and protrusions510locks the removable lens assembly110onto the eye cone210. But the removable lens assembly110can be detached from the eye cone210by pulling the frame420out from the eye cone210with sufficient force.

FIG. 5Ais a rear perspective view of the removable lens assembly110, according to one embodiment. The peripheral wall215of the eye cone210is inserted into inner surface of wall428so that the protrusions510protruding from the inner surface of the wall428snap into the notches343formed on the outer surface of the peripheral wall215. In other embodiments, the peripheral wall215of the eye cone210may be formed with the protrusions whereas the removable lens assembly110is formed with notches.

FIG. 5Bis an exploded view of the removable lens assembly110with the corrective lens410removed from the frame420, in accordance with an embodiment. The side surface415of the corrective lens410is secured to an inner surface515of the frame420. The corrective lens410can be secured to the frame420, for example, by adhesive. However, other securing mechanism such as screws or latches may also be used to secure the corrective lens410to the frame420.

The foregoing description of the embodiments of the disclosure has been presented for the purpose of illustration; it is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed.