TECHNICAL FIELD

The disclosure relates to lens integration and to a combiner lens design that enables mass manufacturing of wearable heads-up displays (WHUDs).

BACKGROUND

WHUDs are wearable electronic devices that use optical combiners to combine real world and virtual images. The optical combiner may be integrated with one or more lenses to provide a combiner lens that may be fitted into a support frame of a WHUD. The combiner lens would provide an eyebox that is viewable from an eye of a user when the WHUD is worn on the head of the user. The combiner lens may include an eyeglass prescription in addition to providing the eyebox. To enable mass manufacturing of the WHUD, a support frame of the WHUD that holds the combiner lens may be provided in standard sizes. However, for a range of users that can wear a given frame size, the prescriptions of the users may vary and/or the eye positions of the users relative to the frame may vary over the range. This generally means that a range of combiner lenses with different prescriptions and/or different eyebox positions may be needed to service the range of users. To enable mass manufacturing of WHUDs, there is a need in the art for a combiner lens design that is adaptable to a wide range of users for a given frame size.

SUMMARY

In a first aspect, a combiner lens may be summarized as including a first lens including a first lens body and a flange integrally formed with the first lens body, the first lens body and flange defining a main cavity, the flange having a first joint surface; a lightguide disposed at least partially in the main cavity; and a second lens including a second lens body positioned in stack with the lightguide and the first lens body, the second lens having a second joint surface in opposing relation to the first joint surface, the second lens attached to the first lens by a joint formed between the first joint surface and the second joint surface.

Variants of the combiner lens according to the first aspect may further include one or more of the features described in A1 to A8 below.

A1: The first joint surface and the second joint surface may be oriented in a vertical direction relative to a plane of the lightguide. Alternatively, the first joint surface and the second joint surface may be oriented in a slanted direction relative to the plane of the lightguide. Alternatively, a first portion of the first joint surface and a first portion of the second joint surface in opposing relation to the first portion of the first joint surface may be oriented in a first direction, and a second portion of the first joint surface and a second portion of the second joint surface in opposing relation to the second portion of the first joint surface may be oriented in a second direction that is different from the first direction. The first direction may be vertical or slanted relative to the plane of the lightguide, and the second direction may be in-plane relative to the plane of the lightguide.

A2: The first lens may include a first lens tab projecting from a periphery of the first lens body. A first portion of the flange may be integrally formed with the first lens body, and a second portion of the flange may be integrally formed with the first lens tab. The second portion of the flange and the first lens tab may define a side cavity. The side cavity may be connected to the main cavity. A first portion of the lightguide carrying an output coupler may be disposed in the main cavity. A second portion of the lightguide carrying an input coupler may be disposed in the side cavity. At least one optical function may be added to the second portion of the flange. The optical function may redirect light that is not coupled into the lightguide. The second portion of the flange may include a lip portion overhanging the first lens tab. The side cavity may be defined between the lip portion and the first lens tab. The lip portion may be optically transparent to permit transmission of light to the side cavity. An aperture may be formed in the lip portion to permit transmission of light to the side cavity. An optical element may be positioned in the aperture to steer light received at the aperture to the input coupler. The optical element may be a prism. A mirror may be positioned relative to the side cavity to reflect light transmitted through the second portion of the lightguide back towards the second portion of the lightguide. An access hole may be formed in the first lens body. The access hole may be connected to the side cavity. A seal cap may be mounted at the access hole. A mirror coating may be applied to a surface of the seal cap exposed to the side cavity. The second lens may include a second lens tab projecting from the second lens body. The first joint surface may include an inner peripheral surface of the lip portion, and the second joint surface may include an outer peripheral surface of the second lens tab.

A3: A first seat may be formed on the first lens body or on the flange. The first seat may be proximate a periphery of the first lens, and the lightguide may be mounted on the first seat. A height of the first seat relative to the stack formed by the first lens body, the lightguide, and the second lens may be set to provide a gap between the first lens body and a major surface of the lightguide that opposes the first lens body.

A4: A second seat may be formed on the flange, and the second lens may be mounted on the second seat. A height of the second seat relative to the stack formed by the first lens body, the lightguide, and the second lens may be set to provide a gap between the second lens and a major surface of the lightguide that opposes the second lens.

A5: The flange may be an annular flange.

A6: The first lens body may be a meniscus lens. Alternatively, the first lens body may be a planoconvex lens.

A7: The second lens body may be a planoconcave lens. Alternatively, the second lens body may be a biconcave lens.

A8: The lightguide may be a planar lightguide.

In a second aspect, a wearable heads-up display may be summarized as including a support frame, which has a frame front and at least one temple coupled to a side of the frame front, and a combiner lens according to the first aspect (or a variation thereof), which is mounted to the frame front.

In a third aspect, a method of forming a combiner lens according to the first aspect (or a variation thereof) may be summarized as including stacking a lightguide relative to a lens body of a first lens by disposing the lightguide in a cavity defined by the lens body of the first lens and a flange of the first lens, positioning a joint surface of a second lens in opposing relation to a joint surface of the flange by stacking the second lens relative to the lightguide and the lens body of the first lens, and attaching the second lens to the first lens by forming a joint between the joint surface of the flange and the joint surface of the second lens.

The foregoing general description and the following detailed description are exemplary of the invention and are intended to provide an overview or framework for understanding the nature of the invention as it is claimed. The accompanying drawings are included to provide further understanding of the invention and are incorporated in and constitute part of this specification. The drawings illustrate various embodiments of the invention and together with the description serve to explain the principles and operation of the invention.

