Patent Application
20250189774
The disclosure generally relates to optical systems. More particularly, the subject matter disclosed herein relates to improvements to catadioptric optical systems for viewing optics of a virtual reality headset.
Virtual reality (VR) headsets have become very popular in a variety of applications including mobile computing applications and social presence applications. One of the main features of VR headsets is that a small display such as a liquid crystal display (LCD) or an organic light emitting diode OLED display (e.g., OLED micro display or μOLED) can be displayed in front of a user's eyes such that the display appears virtually large (e.g., real life size image on the display). This can be achieved by implementing optical lens arrangements on the VR headset between the display and the user's eyes. However, as VR headsets are worn on the user's head, a big, bulky, heavy headset is uncomfortable and will likely not provide the user with a pleasurable experience. Therefore, techniques to manufacture VR headsets that fit comfortably on a user while achieving a high-resolution image, which mimics real-life scenery is desired.
In one or more embodiments, an optical system may include: a first lens; a second lens; a stack of reflective polarizer and quarter waveplate between the first lens and the second lens, the stack of reflective polarizer and quarter waveplate being directly on the first lens; and a half mirror lens by the second lens at a side opposite the first lens.
The stack of reflective polarizer and quarter waveplate and the second lens may define an air gap between the stack of reflective polarizer and quarter waveplate and the second lens.
The stack of reflective polarizer and quarter waveplate may be directly laminated on the first lens.
The first lens may include at least one flat surface.
The second lens may include a first curved surface at a side facing the stack of reflective polarizer and quarter waveplate, and a second curved surface at a side facing the half mirror lens.
The optical system may further include a third lens between the second lens and the half mirror lens.
The second lens may include a first curved surface at a side facing the stack of reflective polarizer and quarter waveplate, and a second curved surface at a side facing the half mirror lens, and wherein the third lens includes a third curved surface at a side facing the second lens, and a fourth curved surface at a side facing the half mirror lens.
The first lens may include at least one flat surface, the second lens may include a second flat surface at a side facing the stack of reflective polarizer and quarter waveplate, and the second flat surface of the second lens may be directly on the reflective polarizer.
The second lens may include a fifth curved surface at a side facing the third lens, and the third lens may include a third curved surface at a side facing the second lens.
The half mirror lens may include a sixth curved surface at a side facing the display, and the half mirror lens may include a seventh curved surface at a side facing the second lens, the seventh curved surface of the half mirror lens abutting the second seventh curved surface of the third lens.
In one or more embodiments, a virtual reality (VR) headset may include an optical system, including: a first lens; a second lens; a stack of reflective polarizer and quarter waveplate between the first lens and the second lens, the stack of reflective polarizer and quarter waveplate being directly on the first lens; and a half mirror lens by the second lens at a side opposite the first lens.
In one or more embodiments, a method for designing an optical system may include: a first lens; a second lens; a stack of reflective polarizer and quarter waveplate between the first lens and the second lens, the stack of reflective polarizer and quarter waveplate being directly on the first lens; and a half mirror lens by the second lens at a side opposite the first lens, wherein the method may include optimizing the optical system by assigning weights to lens parameters based on pupil position relative to an optical axis of the optical system, and wherein the weights are assigned based on a probability of occurrence of the pupil position.
The lens parameters corresponding to pupil position that are closer to the optical axis may be assigned the highest weight, wherein the lens parameters include track length, focal length, and eyebox size.
In one or more embodiments, a system may include: a display configured to emit light corresponding to an image; and an optical catadioptric system configured to transmit the emitted light to a user, the optical catadioptric system including: a first lens having at least one flat surface; a second lens; a stack of reflective polarizer and quarter waveplate between the first lens and the second lens, the stack of reflective polarizer and quarter waveplate being directly on the at least one flat surface of the first lens; and a third lens which is a half mirror lens, between the second lens and the display.
The reflective polarizer and the second lens may define an air gap between the reflective polarizer and the second lens.
The reflective polarizer may be directly laminated on the at least one flat surface of the first lens.
The second lens may include a first convex surface at a side facing the reflective polarizer, and a first concave surface at a side facing the half mirror lens.
The system may further include a third lens between the second lens and the half mirror lens, wherein the second lens includes a first convex surface at a side facing the reflective polarizer, and a first concave surface at a side facing the half mirror lens, and wherein the third lens includes a second convex surface at a side facing the first lens, and a third convex surface at a side facing the half mirror lens.
The system may further include a third lens between the second lens and the half mirror lens, wherein the second lens includes a first flat surface at a side facing the reflective polarizer, and wherein the first flat surface of the second lens is directly on the reflective polarizer.
The second lens may include a first convex surface at a side facing the third lens, and the third lens may include a second concave surface at a side facing the first lens.
The third lens may include a third concave surface at a side facing the half mirror lens, and wherein the half mirror lens includes a second convex surface at a side facing the third lens, the second convex surface of the half mirror lens abutting the second concave surface of the third lens.
In the following section, the aspects of the subject matter disclosed herein will be described with reference to exemplary embodiments illustrated in the figures, in which:
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the disclosure. It will be understood, however, by those skilled in the art that the disclosed aspects may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail to not obscure the subject matter disclosed herein.
Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment disclosed herein. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” or “according to one embodiment” (or other phrases having similar import) in various places throughout this specification may not necessarily all be referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. In this regard, as used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not to be construed as necessarily preferred or advantageous over other embodiments. Additionally, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Also, depending on the context of discussion herein, a singular term may include the corresponding plural forms and a plural term may include the corresponding singular form. Similarly, a hyphenated term (e.g., “two-dimensional,” “pre-determined,” “pixel-specific,” etc.) may be occasionally interchangeably used with a corresponding non-hyphenated version (e.g., “two dimensional,” “predetermined,” “pixel specific,” etc.), and a capitalized entry (e.g., “Counter Clock,” “Row Select,” “PIXOUT,” etc.) may be interchangeably used with a corresponding non-capitalized version (e.g., “counter clock,” “row select,” “pixout,” etc.). Such occasional interchangeable uses shall not be considered inconsistent with each other.
Also, depending on the context of discussion herein, a singular term may include the corresponding plural forms and a plural term may include the corresponding singular form. It is further noted that various figures (including component diagrams) shown and discussed herein are for illustrative purpose only, and are not drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, if considered appropriate, reference numerals have been repeated among the figures to indicate corresponding and/or analogous elements.
The terminology used herein is for the purpose of describing some example embodiments only and is not intended to be limiting of the claimed subject matter. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It will be understood that when an element or layer is referred to as being on, “connected to” or “coupled to” another element or layer, it can be directly on, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to” or “directly coupled to” another element or layer, there are no intervening elements or layers present. Like numerals refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
The terms “first,” “second,” etc., as used herein, are used as labels for nouns that they precede, and do not imply any type of ordering (e.g., spatial, temporal, logical, etc.) unless explicitly defined as such. Furthermore, the same reference numerals may be used across two or more figures to refer to parts, components, blocks, circuits, units, or modules having the same or similar functionality. Such usage is, however, for simplicity of illustration and ease of discussion only; it does not imply that the construction or architectural details of such components or units are the same across all embodiments or such commonly-referenced parts/modules are the only way to implement some of the example embodiments disclosed herein.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this subject matter belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
In some embodiments, the optical lens arrangement 204 may be a catadioptric system. A catadioptric system uses both reflection and refraction to achieve a relatively larger focal point but shortening the track length because the light is not only refracted but also reflected (i.e., light folding) in the catadioptric system to achieve a high-resolution image. Thus, the reflection is achieved through the use of polarization via various polarization filters that may or may not be directly patterned on the lens surface itself.
In some embodiments, the one or more lenses of the catadioptric systems described in the embodiments depicted in
In addition to implementing a catadioptric system in a VR headset at described above, the alignment of the headset on the user's head also has a substantial impact on the user's experience. More particularly, the alignment of the user's eyes relative to the optical axis of the catadioptric system may impact the performance of the VR headset for the particular user. Therefore, when VR headsets are designed, different positions of the user's eyes are taken into account. Consequently, techniques to improve such design processes are desired.
Additionally, because the size of the pupils change depending on the environment (i.e., the pupils enlarge in darker environments whereas they contract in brighter environment), when the pupils contract, the VR headset may become misaligned. To reduce the likelihood of such misalignment, VR headsets may be designed with a relatively large eyebox to keep the user's pupils within the range of the optical axis. An eyebox may be defined as a zone formed around the optical axis in which the user's pupil may be positioned and still achieve an acceptable perceived virtual image (e.g., a non-degraded, non-blurry, non-distorted virtual image). In other words, as long as the pupils are within the zone of the eyebox (i.e., the pupils are within the range of distance of the eyebox zone relative to the optical axis), the virtual image may appear non-degraded to the user. On the other hand, if the user's pupils fall outside of the zone of the eyebox, then the perceived virtual image will appear degraded to the user.
However, instead of designing a VR headset that accommodates the largest possible pupil, or the greatest misalignment of the pupils from the optical axis, an improved method of designing the viewing optics may be envisaged based on the frequency of occurrence of the different pupil sizes and the locations of the pupils relatively to the optical axis, according to one or more embodiments of the present disclosure.
The nominal pupil size for adults is about 4 mm, and most users position the VR headset so that it rests on their head properly and the optical axis aligns with their pupils. However, pupil location relative to the optical axis may vary, for example, it may range from 2 to 10 mm from the nominal pupil location with each pupil location having a different probability of occurrence. For example, there is a greater likelihood of the pupil being on-axis at the nominal position relative to the optical axis because a user will usually try to position the pupil as close as possible to the nominal position when attempting to wear the VR headset. Based on this logic, and according to one or more embodiments of the present disclosure, a data set including all of such pupil locations may be taken into account when designing the lenses for the viewing optics by assigning a weight to each individual displaced pupil location according to the probability of their occurrence. Thus, the locations with the higher probability of occurrence will have a higher weight and the locations with the lower probability of occurrence will have a lower weight. Then the collection of this information may be provided to an optimization engine of an optical software, known to those having ordinary skill in the art, and generate unique lens profiles, which may result in a more consistent eyebox imaging performance. The steps taken by the optical software are beyond the scope of the embodiments of the present disclosure and therefore will not be described herein.
While this specification may contain many specific implementation details, the implementation details should not be construed as limitations on the scope of any claimed subject matter, but rather be construed as descriptions of features specific to particular embodiments. Certain features that are described in this specification in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination may in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.
Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.
Thus, particular embodiments of the subject matter have been described herein. Other embodiments are within the scope of the following claims. In some cases, the actions set forth in the claims may be performed in a different order and still achieve desirable results. Additionally, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In certain implementations, multitasking and parallel processing may be advantageous.
As will be recognized by those skilled in the art, the innovative concepts described herein may be modified and varied over a wide range of applications. Accordingly, the scope of claimed subject matter should not be limited to any of the specific exemplary teachings discussed above, but is instead defined by the following claims and their equivalents.
This application claims the priority benefit under 35 U.S.C. § 119 (e) of U.S. Provisional Application No. 63/608,520, filed on Dec. 11, 2023, the disclosure of which is incorporated by reference in its entirety as if fully set forth herein.
| Number | Date | Country | |
|---|---|---|---|
| 63608520 | Dec 2023 | US |
