IMAGE PROJECTION SYSTEM

Abstract

An image projection system comprises a stack of layers defining an inner cavity and a microelectromechanical system (MEMS) mirror located within that cavity. The stack of layers includes a first glass layer, a first semiconductor crystal layer, a second semiconductor crystal layer, and a second glass layer, the inner surfaces of which define the inner cavity. The second semiconductor crystal layer includes a first internal inclined surface and a second internal inclined surface that define a portion of the inner cavity. The first internal inclined surface is configured to receive light rays from a light source and direct them toward the second internal inclined surface. The second internal inclined surface is configured to receive light rays from the first internal inclined surface and direct them toward the MEMS mirror.The MEMS mirror is configured to direct the light beams to render an image.

Description

BACKGROUND

[0001] Augmented Reality (AR) is a technology that provides an interactive user experience by combining real-world and computer-generated content. AR delivers visual, audio, haptic, and / or other sensory information to a user to modify their ongoing perception of a real-world environment in real time. In other words, AR adds digital elements to a live experience of the real environment. The sensory information overlaid on the real environment can be constructive, adding sensory information to the real environment, or destructive, masking part of the real environment. The sensory information can be delivered to the user through a device, such as a mobile device. For example, a perceived part of the real environment can be augmented with digital information overlaid upon it.In some cases, visual content can be overlaid onto the user's line of sight (e.g., the user's actual view). Thus, digital content can be superimposed onto the perceived part of the environment to provide the user with additional visual information. The digital content can be displayed on a transparent substrate or display, such as smart glasses, smart contact lenses, head-up displays (HUDs), and head-mounted displays (HMDs), or projected directly onto the user's retina, as is the case with virtual retinal displays.

[0002] Virtual Reality (VR) is a technology that creates a completely artificial, computer-generated environment in which a user is immersed. Thus, the user's perception of reality is based entirely on virtual information. The user can experience a virtually rendered environment with sight and sound through a VR headset or a multi-projected environment. For example, computer-generated stereo views can place the user within the virtually rendered environment, providing an immersive experience designed to simulate sensations the user would otherwise experience in the real world.

[0003] Mixed Reality (MR) is a technology that combines elements of both AR and VR, allowing real and digital objects to interact in real time. MR enables real and virtual elements to interact with each other and allows the user to interact with the virtual elements as they would in the real world. Here, a real environment is blended with a virtual one. Because MR maintains a connection to the real world, it is not considered a fully immersive experience like VR. The user can experience an MR environment using an MR headset or MR glasses.

[0004] These technologies, as well as others that interact with a user's senses, can be referred to as augmented reality (XR) technologies.

[0005] US 2013 / 0094003 A1 describes a MEMS micromirror device comprising a single housing, a first mirror and a second mirror, wherein at least one of the mirrors is configured to oscillate along an axis of oscillation, wherein both mirrors are located within the single housing and are arranged such that when the at least one mirror oscillates, the light incident on the first micromirror can be deflected to the second mirror. SUMMARY

[0006] In some implementations, an image projection system comprises a light source configured to produce light beams corresponding to an image; a layer stack defining an inner cavity, wherein the layer stack comprises: a first glass layer; a first semiconductor crystal layer arranged on top of the first glass layer; a second semiconductor crystal layer arranged on top of the first semiconductor crystal layer; and a second glass layer arranged on top of the second semiconductor crystal layer, wherein the inner surfaces of the first glass layer, the first semiconductor crystal layer, the second semiconductor crystal layer, and the second glass layer define the inner cavity; and a mirror of a microelectromechanical system (MEMS) located in the inner cavity and suspended from the first semiconductor crystal layer.wherein the second semiconductor crystal layer comprises a first inner inclined surface and a second inner inclined surface optically coupled to the first inner inclined surface, wherein the first inner inclined surface and the second inner inclined surface define a section of the inner cavity, wherein the first inner inclined surface is configured to receive the light rays from the light source and direct the light rays towards the second inner inclined surface, wherein the second inner inclined surface is configured to receive the light rays from the first inner inclined surface and direct the light rays towards the MEMS mirror, and wherein the MEMS mirror is configured to direct the light rays to render the image.

[0007] In some implementations, an image projection system comprises a light source configured to produce light beams corresponding to an image; a stack of layers defining an inner cavity, wherein the stack of layers comprises: a first glass layer; a first semiconductor crystal layer arranged on top of the first glass layer; a second semiconductor crystal layer arranged on top of the first semiconductor crystal layer; and a second glass layer arranged on top of the second semiconductor crystal layer, wherein the inner surfaces of the first glass layer, the first semiconductor crystal layer, the second semiconductor crystal layer, and the second glass layer define the inner cavity; and a MEMS mirror arranged in the inner cavity and suspended from the first semiconductor crystal layer.a first grating arranged on the first glass layer within the inner cavity at an entrance side of the inner cavity; and a deflection element arranged within the inner cavity at an exit side of the inner cavity, wherein the deflection element is optically coupled to the first grating, the first grating being configured to receive the light rays from the light source and direct the light rays towards the deflection element, the deflection element being configured to receive the light rays from the first grating and direct the light rays towards the MEMS mirror, and the MEMS mirror being configured to direct the light rays to render the image.

[0008] In some implementations, an image projection system comprises a light source configured to generate light beams corresponding to an image; a layer stack defining an inner cavity, wherein the layer stack comprises: a first glass layer; a first semiconductor crystal layer arranged on top of the first glass layer; a second semiconductor crystal layer arranged on top of the first semiconductor crystal layer; and a second glass layer arranged on top of the second semiconductor crystal layer, the inner surfaces of the first glass layer, the first semiconductor crystal layer, the second semiconductor crystal layer, and the second glass layer defining the inner cavity; a MEMS mirror located in the inner cavity and suspended from the first semiconductor crystal layer; and coupling optics configured to couple the light beams through the first glass layer into the inner cavity.and a deflection element arranged within the inner cavity at an exit side of the inner cavity, wherein the deflection element is optically coupled to the coupling optics, wherein the coupling optics are configured to receive the light rays from the light source and direct the light rays towards the deflection element, wherein the deflection element is configured to receive the light rays from the coupling optics and direct the light rays towards the MEMS mirror, and wherein the MEMS mirror is configured to direct the light rays to render the image.

[0009] In some implementations, an image projection system comprises a light source configured to produce light beams corresponding to an image; a stack of layers defining an inner cavity, wherein the stack of layers comprises: a first glass layer; a first semiconductor crystal layer arranged on top of the first glass layer; a second semiconductor crystal layer arranged on top of the first semiconductor crystal layer; and a second glass layer arranged on top of the second semiconductor crystal layer, wherein the inner surfaces of the first glass layer, the first semiconductor crystal layer, the second semiconductor crystal layer, and the second glass layer define the inner cavity; and a MEMS mirror arranged in the inner cavity and suspended from the first semiconductor crystal layer.and a coupling optic configured to couple the light rays through the second glass layer into the inner cavity, wherein the coupling optic is configured to receive the light rays from the light source and direct the light rays into the inner cavity, and wherein the MEMS mirror is configured to direct the light rays to render the image. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Implementations are described herein with reference to the attached drawings. Fig. 1A is a cross-section of an image projection system according to one or more implementations. Fig. 1B is a cross-section of a layer stack of the material in conjunction with Fig. 1A described image projection system. Fig. 2A is a cross-section of an image projection system according to one or more implementations. Fig. 2B is a cross-section of a layer stack of the material in conjunction with Fig. 2A described image projection system. Fig. 3A is a cross-section of an image projection system according to one or more implementations. Fig. 3B is a cross-section of an image projection system according to one or more implementations. Fig. 3C is a cross-section of an image projection system according to one or more implementations. Fig. 3D is a cross-section of an image projection system according to one or more implementations. Fig. 3E is a cross-section of an image projection system according to one or more implementations. Fig. 4A is a cross-section of an image projection system according to one or more implementations. Fig. 4B is a cross-section of an image projection system according to one or more implementations. Fig. Figure 5 is a diagram of an augmented reality glasses device according to one or more embodiments. DETAILED DESCRIPTION

[0011] Details are set forth below to provide a more thorough explanation of exemplary implementations. However, it is obvious to experts in the field that these implementations can be executed without these specific details. In other cases, well-known structures and devices are shown in block diagram form or in a schematic view, rather than in detail, to avoid obscuring the implementations. Furthermore, features of the various implementations described below can be combined unless explicitly stated otherwise.

[0012] Furthermore, equivalent or identical elements, or elements with equivalent or identical functionality, are designated by equivalent or identical reference numerals in the following description. Since identical or functionally equivalent elements in the figures are provided with the same reference numerals, a repeated description for elements with the same reference numerals can be omitted. Therefore, descriptions provided for elements with the same or identical reference numerals are mutually interchangeable.

[0013] Each of the illustrated x-axis, y-axis, and z-axis is essentially perpendicular to the other two axes. In other words, the x-axis is essentially perpendicular to the y-axis and the z-axis, the y-axis is essentially perpendicular to the x-axis and the z-axis, and the z-axis is essentially perpendicular to the x-axis and the y-axis. In some cases, a single reference symbol is shown to refer to a surface, or fewer than all instances of a part may be labeled with all surfaces of that part. All instances of the part may include associated surfaces of that part, although not every surface is labeled.

[0014] The orientations of the various elements in the figures are shown as examples, and the illustrated examples may be rotated relative to the depicted orientations. The descriptions provided herein and the following claims apply to any structures exhibiting the described relationships between various features, regardless of whether the structures are in the specific orientation shown in the drawings or rotated relative to such an orientation. Likewise, spatially relative terms such as "above," "below," "under," "lesser," "above," "upper," "middle," "left," and "right" are used herein for the sake of simplicity to describe the relationship of one element to one or more other elements, as illustrated in the figures.The spatially relative terms are intended to encompass various orientations of the element, structure, and / or arrangement during use or operation, in addition to those depicted in the figures. A structure and / or arrangement may be oriented differently (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein may be interpreted accordingly. Furthermore, the cross-sectional views in the figures show only features within the planes of the cross-sections and do not show materials behind the planes of the cross-sections unless otherwise indicated, for the sake of simplicity.

[0015] It is understood that when an element is described as "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intervening elements. In contrast, when an element is described as "directly connected" or "directly coupled" to another element, there are no intervening elements. Other words used to describe the relationship between elements should be interpreted in the same way (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.).

[0016] In the implementations described herein or shown in the drawings, any direct electrical connection or coupling (e.g., any connection or coupling without any additional intervening elements) can also be implemented by an indirect connection or coupling (e.g., a connection or coupling with one or more additional intervening elements, or vice versa), as long as the general purpose of the connection or coupling (e.g., to transmit a certain type of signal or to transmit a certain type of information) is substantially maintained. Features from different implementations can be combined to form other implementations. For example, variations or modifications described with respect to one of the implementations may also be applicable to other implementations unless otherwise stated.

[0017] For example, the terms "essentially" and "approximately" may be used herein to account for small manufacturing tolerances or other factors (e.g., within 5%) that are considered acceptable in the industry without deviating from the aspects of the implementations described herein. For example, a resistor with an approximate resistance value may practically have a resistance within 5% of the approximate resistance value. As another example, a signal with an approximate signal value may practically have a signal value within 5% of the approximate signal value.

[0018] In the present disclosure, expressions, including ordinal numbers such as "first," "second," and / or the like, may modify various elements. However, such elements are not restricted by such expressions. For example, such expressions do not restrict the order and / or importance of the elements. Instead, such expressions are used merely for the purpose of distinguishing one element from the other elements. For example, a first box and a second box denote different boxes, although both are boxes. By another example, a first element could be designated as a second element, and likewise, a second element could also be designated as a first element, without departing from the scope of the present disclosure.

[0019] Wearable headgear, such as glasses and head-mounted displays (HMDs), can be used in augmented reality (XR) technologies. For example, augmented reality (AR) is a technology that enhances physical environments on a mobile device's screen by overlaying them with digital content. AR adds digital elements to a live view. For instance, a captured piece of an environment is enhanced with digital information superimposed on it. Thus, digital content is overlaid onto the captured piece of the environment to provide a user with additional visual information. The digital content can be projected directly onto a user's retina, as is the case with virtual retinal displays. Virtual reality (VR) is a technology that completely replaces a user's real-world environment with a computer-generated virtual environment.Thus, a user is presented with a completely digital environment in which computer-generated stereoscopic views surround them. In a simulated VR environment, a VR headset can be used, providing a 360-degree view. A mixed reality (MR) experience combines elements of both AR and VR, allowing real and digital objects to interact. Here, a real environment is blended with a virtual one. These technologies, as well as others that enhance a user's senses, can be referred to as XR technologies.

[0020] Binocular vision can be implemented in image projection systems and can be used in some XR technologies by projecting images into both of the user's eyes. In some XR technologies, stereoscopic imaging can be used to create an illusion of depth by projecting two slightly offset images separately into each of the user's eyes. For example, the two slightly offset images (e.g., two stereo images) could be of the same scene or object, but with the illusion of being projected from slightly different angles or perspectives. In other words, the two stereo images can be combined to create a stereoscopic image that exhibits the illusion of depth. The generation of the two stereo images should be synchronized so that the user correctly perceives a coherent image with the illusion of depth.

[0021] When an image projection system is implemented in a wearable headgear, such as goggles, reducing the size or footprint of the system may be a top priority to reduce mass and increase user comfort. Additionally, the use of curved glass in the image projection system can increase its complexity and cost. For example, curved glass typically adds mass to the system. Furthermore, curved glass is more difficult to manufacture and therefore more expensive than flat glass. A more compact image projection system that uses flat glass instead of curved glass may be desirable.

[0022] Some implementations disclosed herein are directed towards a compact image projection system that utilizes flat glass structures. Thus, the compact image projection system can be free of curved glass structures. The compact image projection system can have a vertically stacked arrangement to reduce its lateral footprint. For example, the compact image projection system can be smaller than 0.3 cm. 3 , especially smaller than 0.2 cm3, as opposed to > 1.0 cm 3 It can be manufactured using conventional image projection systems. The compact image projection system can be a light engine or image generating unit that is optically coupled to a lens of a pair of spectacles. The compact image projection system can be duplicated for each lens of the spectacles.

[0023] Fig. Figure 1A is a cross-section of an image projection system 100 according to one or more implementations. The image projection system 100 can be implemented as an image generating unit or light generator for eyeglasses. In other words, the image projection system 100 can be a portable image projection system that includes an eyeglass lens. The image projection system 100 can include a light source 102, a printed circuit board (PCB) 104 mounted on the light source 102, one or more drivers 106 mounted on the PCB 104, a layer stack 108 mounted on the PCB 104, and an output waveguide 110 mounted on the layer stack 108.

[0024] The light source 102 can be a light source, such as a red-green-blue (RGB) light source comprising discrete red, green, and blue light sources. The light source 102 can generate light beams corresponding to an image, such as an RGB image. The light source 102 can be configured to couple the light beams into the layer stack 108.

[0025] The output waveguide 110 can be a lens of a pair of spectacles or can be coupled to the lens of a spectacle to deliver the light beams to a user's eye. Thus, the output waveguide 110 can be configured to direct the light beams coupled out of the layer stack 108 towards a user's eye.

[0026] The layer stack 108 is arranged between the light source 102 and the output waveguide 110. The layer stack 108 defines an internal cavity 112 in which the light beams are manipulated. The layer stack 108 comprises a first glass layer 114 (e.g., a bottom glass layer), a first semiconductor crystal layer 116 arranged on the first glass layer 114, a bonding interface 118, a second semiconductor crystal layer 120 arranged on the first semiconductor crystal layer 116, and a second glass layer 122 (e.g., an top glass layer) arranged on the second semiconductor crystal layer 120. The first glass layer 114 and the second glass layer 122 are flat glass structures. The output waveguide 110 is arranged on the second glass layer 122. The light emitter 102 is coupled to the first glass layer 114 (e.g. indirectly via the PCB 104) opposite the first semiconductor crystal layer 116.The inner surfaces of the first glass layer 114, the first semiconductor crystal layer 116, the second semiconductor crystal layer 120 and the second glass layer 122 define the inner cavity 112.

[0027] The bonding interface 118 can bond the first semiconductor crystal layer 116 and the second semiconductor crystal layer 120. For example, the bond can be a glass frit bond, a fusion bond, or an anodic bond. Thus, in some implementations, the bonding interface 118 can be glass (e.g., for glass frit bonding or anodic bonding). For anodic bonding, the bonding interface 118 can be a glass layer (e.g., a third glass layer) to which both the first semiconductor crystal layer 116 and the second semiconductor crystal layer 120 are bonded.

[0028] The image projection system 100 can further comprise a mirror of a microelectromechanical system (MEMS) 124, which is arranged in the inner cavity 112 and suspended from the first semiconductor crystal layer 116. The MEMS mirror 124 can be suspended above a rear cavity 126 formed in the first semiconductor crystal layer 116. The MEMS mirror 124 can be implemented as a scanning structure configured to direct or otherwise deflect light beams according to a scanning pattern. The MEMS mirror 124 is a mechanical motion mirror (e.g., a MEMS micromirror) configured to rotate or oscillate about two scanning axes, which are typically orthogonal to each other. For example, the two scanning axes can include a first scanning axis that allows the MEMS mirror 124 to scan light in a first scanning direction (e.g.,The MEMS mirror 124 has a first scanning axis (e.g., x-direction) and a second scanning axis that allows it to direct light in a second scanning direction (e.g., y-direction). As a result, the MEMS mirror 124 can direct light rays in two dimensions.

[0029] The one or more drivers 106 can be electrically connected to the light source 102 or the MEMS mirror 124 via the PCB 104. For example, one driver of the one or more drivers 106 can drive the light source 102 to generate light beams (e.g., light pulses), and another driver of the one or more drivers 106 can drive the MEMS mirror 124 around the two scanning axes. In some implementations, a separate MEMS driver can be used for each scanning axis.

[0030] The image projection system 100 can further include coupling optics 128, which are configured to couple the light rays into the inner cavity 112 through the first glass layer 114. For example, the coupling optics 128 can be a concave mirror, such as a collimating mirror. The coupling optics 128 can receive the light rays from the light source 102 and couple the light rays into the inner cavity 112 through an opening 130 formed in the PCB 104. Thus, the light rays can enter the inner cavity 112 and pass through the opening 130 and through the first glass layer 114.

[0031] The second semiconductor crystal layer 120 comprises a first inner inclined surface 132 and a second inner inclined surface 134, which is optically coupled to the first inner inclined surface 132. The first inner inclined surface 132 and the second inner inclined surface 134 can be reflective surfaces. For example, the first inner inclined surface 132 and the second inner inclined surface 134 can be polished surfaces or can have a thin reflective layer, such as aluminum, deposited on them. The first inner inclined surface 132 and the second inner inclined surface 134 can define a section of the inner cavity 112. The first inner inclined surface 132 is configured to receive the light rays from the light source 102 (e.g., from the coupling optics 128) and direct the light rays toward the second inner inclined surface 134.The second inner inclined surface 134 is configured to receive the light rays from the first inner inclined surface 132 and direct them towards the MEMS mirror 124. The MEMS mirror 124 is configured to direct the light rays to render the image. The MEMS mirror 124 can direct the light rays towards the output waveguide 110. Thus, the layer stack 108 can be configured such that the light rays are coupled into the inner cavity 112 through the first glass layer 114 and coupled out of the inner cavity 112 through the second glass layer 122. The output waveguide 110 can receive the light rays from the MEMS mirror 124 and direct them towards the user's eye.

[0032] The first inner inclined surface 132 and the second inner inclined surface 134, together with the stacking configuration of the image projection system 100, enable the image projection system 100 to be more compact in a lateral dimension than conventional designs. The first inner inclined surface 132 and the second inner inclined surface 134 are crystallographic surfaces of the second semiconductor crystal layer 120. "Crystallographic surface" can refer to a flat, outer boundary of a crystal that corresponds to a specific arrangement of atoms in a crystalline material. In crystallography, these surfaces are usually described in terms of their Miller indices, which are integers that denote the orientation of a crystal plane relative to the axes of the crystal lattice.

[0033] In some implementations, the first semiconductor crystal layer consists of 116 silicon crystal layers and the second semiconductor crystal layer consists of 120 silicon crystal layers. The crystallographic surfaces of silicon (Si), like other crystals, are defined by the orientations of planes in the crystal lattice. Silicon has a cubic diamond structure, meaning that its atoms are arranged in a very specific repeating pattern. The angles at which surfaces can be formed depend on how the surface is oriented with the planes of atoms in the crystal. A (100) lattice plane or surface is parallel to one of the cubic faces of the silicon lattice. This (100) surface is one of the most commonly used in semiconductor fabrication because it allows for a relatively simple atomic arrangement. An angle between the (100) surface and a (110) surface of a silicon crystal is 45°.The angle between surface (100) and surface (111) of a silicon crystal is 54.74°. The first internal inclined surface 132 and the second internal inclined surface 134 can be etched along boundaries corresponding to a crystallographic surface. Thus, the first internal inclined surface 132 can extend at a first angle of 45° or 54.74°, and the second internal inclined surface 134 can extend at a second angle of 45° or 54.74°. The MEMS mirror 124 can be positioned within the inner cavity 112 according to the combination of the first and second angles, such that the MEMS mirror 124 is aligned with the optical path to receive the light rays from the second internal inclined surface 134.

[0034] The image projection system 100 can further comprise a waveguide grid 136 coupled to the output waveguide 110. The waveguide grid 136 can be arranged on an upper surface of the output waveguide 110 on one side opposite the second glass layer 122. The waveguide grid 136 can receive the light rays from the MEMS mirror 124 and couple the light rays into the output waveguide 110. Thus, the waveguide grid 136 can guide the light rays along a waveguide path of the output waveguide 110.

[0035] As stated above, Fig. 1A is provided as an example. Other examples may differ from what is provided in relation to Fig. 1A is described.

[0036] Fig. 1B is a cross-section of the layer stack 108 of the in conjunction with Fig. 1A described image projection system 100. The layer stack 108 is configured such that the light rays are coupled into the inner cavity 112 through the first glass layer 114 and are coupled out of the inner cavity 112 through the second glass layer 122.

[0037] As stated above, Fig. 1B is provided as an example. Other examples may differ from what is provided in relation to Fig. 1B is described.

[0038] Fig. Figure 2A is a cross-section of an image projection system 200 according to one or more implementations. The image projection system 200 can be implemented as an image generating unit or light generator for eyeglasses. In other words, the image projection system 200 can be a portable image projection system comprising an eyeglass lens. The image projection system 200 can include a light source 202, a PCB 204, one or more drivers 206, a layer stack 208, and an output waveguide 210 arranged on the layer stack 208. In this example, the light source 202 is arranged on the output waveguide 210 opposite the layer stack 208.

[0039] The layer stack 208 can be arranged on the PCB 204 and can define an internal cavity 212. The layer stack 208 can comprise a first glass layer 214, a first semiconductor crystal layer 216 arranged on the first glass layer 214, a bonding interface 218, a second semiconductor crystal layer 220 arranged on the first semiconductor crystal layer 216 (e.g., on the bonding interface 218), and a second glass layer 222 arranged on the second semiconductor crystal layer 220. The output waveguide 210 is arranged on the second glass layer 222. The light emitter 202 can be coupled to the output waveguide 110 opposite the second glass layer 222.

[0040] The inner surfaces of the first glass layer 214, the first semiconductor crystal layer 216, the second semiconductor crystal layer 220, and the second glass layer 222 can define the inner cavity 212. A MEMS mirror can be arranged in the inner cavity 212 and can be suspended above a rear cavity 226 formed in the first semiconductor crystal layer 216.

[0041] The bonding interface 218 can bond the first semiconductor crystal layer 216 and the second semiconductor crystal layer 220. For example, the bonding can be a glass frit bond, a fusion bond, or an anodic bond. Thus, in some implementations, the bonding interface 218 can be glass (e.g., for glass frit bonding or anodic bonding).

[0042] The image projection system 200 can further include coupling optics 228, which are configured to couple the light rays into the inner cavity 112 through the second glass layer 222. For example, the coupling optics 228 can be a concave mirror, such as a collimating mirror. The coupling optics 228 can receive the light rays from the light source 102 and couple the light rays into the inner cavity 112 through the second glass layer 222.

[0043] The second semiconductor crystal layer 220 comprises a first inner inclined surface 232 and a second inner inclined surface 234, which is optically coupled to the first inner inclined surface 232. The first inner inclined surface 232 and the second inner inclined surface 234 define a section of the inner cavity 212. The first inner inclined surface 232 can be configured to receive light rays from the light source 202 (e.g., from the coupling optics 228) and direct the light rays toward the second inner inclined surface 234. The second inner inclined surface 234 can be configured to receive light rays from the first inner inclined surface 232 and direct the light rays toward the MEMS mirror 224. The MEMS mirror 224 can direct the light rays to render the image. The MEMS mirror 224 can direct the light rays towards the output waveguide 210.Thus, the layer stack 208 can be configured such that the light rays are coupled into the inner cavity 212 through the second glass layer 222 and coupled out of the inner cavity 212 through the second glass layer 222. The output waveguide 110 can receive the light rays from the MEMS mirror 224 and direct the light rays towards the user's eye.

[0044] Similar to the first internal inclined surface 132 and the second internal inclined surface 134, the first internal inclined surface 232 and the second internal inclined surface 234 can be crystallographic surfaces. For example, the first internal inclined surface 232 can extend at a first angle of 45° or 54.74°, and the second internal inclined surface 134 can extend at a second angle of 45° or 54.74°.

[0045] The image projection system 200 can further comprise a waveguide grid 236 coupled to the output waveguide 210. The waveguide grid 236 can be arranged on an upper surface of the output waveguide 210 on one side opposite the second glass layer 222. The waveguide grid 236 can receive the light rays from the MEMS mirror 224 and couple the light rays into the output waveguide 210. Thus, the waveguide grid 236 can guide the light rays along a waveguide path of the output waveguide 210.

[0046] As stated above, Fig. 2A is provided as an example. Other examples may differ from what is provided in relation to Fig. 2A is described.

[0047] Fig. 2B is a cross-section of the layer stack 208 of the in conjunction with Fig. 2A described image projection system 200. The layer stack 208 is configured such that the light rays are coupled into the inner cavity 112 through the second glass layer 222 and are coupled out of the inner cavity 112 through the second glass layer 222.

[0048] As stated above, Fig. 2B is provided as an example. Other examples may differ from what is provided in relation to Fig. 2B is described.

[0049] Fig. 3A is a cross-section of an image projection system 300A according to one or more implementations. The image projection system 300A can be used in conjunction with Fig. 1A and Fig. Image projection system 100 described in 1B may be similar, except that image projection system 300A may not have internal inclined surfaces. Instead, deflecting elements, such as gratings, reflectors, or mirrors, may be used within an internal cavity to direct light rays along an optical path.

[0050] The image projection system 300A can comprise a light emitter 302, a PCB 304, one or more drivers 306, a layer stack 308 defining an inner cavity 312, and an output waveguide. The layer stack comprises a first glass layer 314, a first semiconductor crystal layer 316 arranged on the first glass layer 314, a bonding interface 318, a second semiconductor crystal layer 320 arranged on the first semiconductor crystal layer 316 (e.g., on the bonding interface 318), and a second glass layer 322 arranged on the second semiconductor crystal layer 320. The inner surfaces of the first glass layer 314, the first semiconductor crystal layer 316, the second semiconductor crystal layer 320, and the second glass layer 322 can define the inner cavity 312.A MEMS mirror 324 can be arranged in the inner cavity 312 and suspended above a rear cavity 326 formed in the first semiconductor crystal layer 316.

[0051] The output waveguide 310 can be arranged on the second glass layer 322. The output waveguide can receive the light beams from the MEMS mirror 324 and direct the light beams towards a user's eye. A waveguide grid 336 can be coupled to the output waveguide 310 and can receive the light beams from the MEMS mirror 124 and couple the light beams into the output waveguide 310.

[0052] The light source 302 can be coupled to the first glass layer 314 opposite the first semiconductor crystal layer 316. Coupling optics 328 can couple the light beams from the light source 302 into the inner cavity 312 through an opening 330 formed by the PCB 304. The light beams can pass through the opening 330 and through the first glass layer 314 to enter the inner cavity 312. Thus, the layer stack 308 can be configured such that the light beams are coupled into the inner cavity 312 through the first glass layer 314 and coupled out of the inner cavity through the second glass layer 322.

[0053] The image projection system 300A can further comprise a first grating 338, which is arranged on the first glass layer 314 inside the inner cavity 312 at an entrance side of the inner cavity 312. The first grating 338 can receive the light rays from the coupling optics 328. The image projection system 300A can further comprise a deflection element 340, which is arranged inside the inner cavity 312 at an exit side of the inner cavity 312. The deflection element 340 can be arranged on an inner surface of the second glass layer 322 or on an inner surface of the second semiconductor crystal layer 320. In this example, the deflection element 340 is arranged on an inner surface of the second glass layer 322. The deflection element 340 can be a second grating or a reflecting element. The deflection element 340 can be optically coupled to the first grating 338.The first grating 338 can be configured to receive the light beams from the light source 302 (e.g., from the coupling optic 328) and direct the light beams toward the deflecting element 340. The deflecting element 340 can receive the light beams from the first grating 338 and direct them toward the MEMS mirror 324. The MEMS mirror 324 can then direct the light beams to render the image.

[0054] The image projection system 300A can further comprise a light-blocking layer 342 arranged above the deflection element 340 to prevent light from escaping into the output waveguide 310. Thus, the light-blocking layer 342 can be arranged between the deflection element 340 and the output waveguide 310. In some implementations, the light-blocking layer 342 can be arranged on the second glass layer 322 (e.g., between the second glass layer 322 and the output waveguide 310).

[0055] As stated above, Fig. 3A is provided as an example. Other examples may differ from what is provided in relation to Fig. 3A is described.

[0056] Fig. 3B is a cross-section of a 300B image projection system according to one or more implementations. The 300B image projection system can be used in conjunction with Fig. The image projection system 300A described in 3A is similar, except that the positions of the deflection element 340 and the light-blocking layer 342 are shifted to the right. The first grating 338 can be configured to receive the light rays from the light source 302 (e.g., from the coupling optics 328) and direct the light rays toward the deflection element 340. The deflection element 340 can receive the light rays from the first grating 338 and direct the light rays toward the MEMS mirror 324. The MEMS mirror 324 can direct the light rays to render the image.

[0057] As stated above, Fig. 3B is provided as an example. Other examples may differ from what is provided in relation to Fig. 3B is described.

[0058] Fig. 3C is a cross-section of a 300C image projection system according to one or more implementations. The 300C image projection system can be used in conjunction with Fig. The image projection system 300A described in 3A is similar, except that the deflection element 340 is arranged on an inner surface of the second semiconductor crystal layer 320. The second semiconductor crystal layer 320 can have an overhang section that extends over a section of the MEMS mirror 324. The deflection element 340 can be arranged on an inner surface of the overhang section. A section of the second glass layer 322 can be arranged on an outer surface of the overhang section.

[0059] As stated above, Fig. 3C is provided as an example. Other examples may differ from what is provided in relation to Fig. 3C is described.

[0060] Fig. 3D is a cross-section of a 300D image projection system according to one or more implementations. The 300D image projection system can be used in conjunction with Fig. The image projection system 300C described in Section 3C is similar, except that the deflection element 340 is shifted to the right. The second semiconductor crystal layer 320 can have an overhang section that extends over a section of the MEMS mirror 324. The deflection element 340 can be located on an inner surface of the overhang section. A section of the second glass layer 322 can be located on an outer surface of the overhang section.

[0061] As stated above, Fig. 3D is provided as an example. Other examples may differ from what is described in terms of Fig. It is described in 3D.

[0062] Fig. 3E is a cross-section of a 300E image projection system according to one or more implementations. The 300E image projection system can be used in conjunction with Fig. The image projection system 300D described in 3D is similar, except that the image projection system 300E does not include the first grating 338. As a result, the coupling optics 328 can couple the light rays into the inner cavity 312 through the first glass layer 314, and the deflection element can be optically coupled to the coupling optics 328. Thus, the coupling optics 328 can receive the light rays from the light source 302 and direct the light rays toward the deflection element 340. The deflection element 340 can receive the light rays from the coupling optics 328 and direct the light rays toward the MEMS mirror 324. The MEMS mirror 324 can direct the light rays to render an image. The output waveguide 310 is arranged on the second glass layer 322 to receive the light rays from the MEMS mirror 324 and direct the light rays towards a user's eye.

[0063] The deflection element 340 can be arranged on an inner surface of the second glass layer 322 or on an inner surface of the second semiconductor crystal layer 320.

[0064] The layer stack is configured such that the light rays are coupled into the inner cavity 312 through the first glass layer 314 and coupled out of the inner cavity 312 through the second glass layer 322.

[0065] As stated above, Fig. 3E is provided as an example. Other examples may differ from what is provided in relation to Fig. 3E is described.

[0066] Fig. 4A is a cross-section of an image projection system 400A according to one or more implementations. The image projection system 400A may not have any internal inclined surfaces. The image projection system 400A may include a light emitter 402, a PCB 404, one or more drivers 406, a layer stack 408, and an output waveguide 410.

[0067] The layer stack 408 can be arranged on the PCB 404 and can define an internal cavity 412. Additionally, the layer stack 408 can comprise a first glass layer 414, a first semiconductor crystal layer 416 arranged on the first glass layer 414, a bonding interface 418, a second semiconductor crystal layer 420 arranged on the first semiconductor crystal layer 416 (e.g., on the bonding interface 418), and a second glass layer 422 arranged on the second semiconductor crystal layer 420. The internal surfaces of the first glass layer 414, the first semiconductor crystal layer 416, the second semiconductor crystal layer 420, and the second glass layer 422 can define the internal cavity 412. A MEMS mirror 424 can be arranged in the inner cavity 412 and suspended above a rear cavity 426 formed in the first semiconductor crystal layer 416.

[0068] The coupling optics 428 can be configured to receive light beams from the light source 402 and couple the light beams into the inner cavity 412 through the second glass layer 422. The coupling optics 428 can be optically coupled to the MEMS mirror 424. Thus, the MEMS mirror 424 can receive the light beams from the coupling optics 428 and direct them to render an image. The output waveguide 410, located on the second glass layer 422, can receive the light beams from the MEMS mirror 424 and direct them toward a user's eye. A waveguide grating 436 can be coupled to the output waveguide 410 and can receive the light beams from the MEMS mirror 424 and couple them into the output waveguide 410.Thus, the layer stack 408 can be configured such that the light rays are coupled into the inner cavity 412 through the second glass layer 422 and are coupled out of the inner cavity 412 through the second glass layer 422.

[0069] As stated above, Fig. 4A is provided as an example. Other examples may differ from what is provided in relation to Fig. 4A is described.

[0070] Fig. 4B is a cross-section of a 400B image projection system according to one or more implementations. The 400B image projection system can be used in conjunction with Fig. The image projection system 400A described in 4A may be similar, except that the image projection system 400B may include a grating 444 arranged on the second glass layer 422 within the inner cavity 412. For example, the grating 444 may be arranged on an inner surface of the second glass layer 422. The grating 444 may be optically coupled to the coupling optics 428 and the MEMS mirror 424. Thus, the coupling optics 428 may be configured to direct the light beams toward the grating 444, and the grating 444 may be configured to receive the light beams from the coupling optics 428 and direct the light beams toward the MEMS mirror 424.

[0071] As stated above, Fig. 4B is provided as an example. Other examples may differ from what is provided in relation to Fig. 4B is described.

[0072] Fig. Figure 5 is a diagram of an augmented reality glasses 500 according to one or more embodiments. The augmented reality glasses 500 can comprise two image projection systems 501a and 501b coupled to respective spectacle lenses 510a and 510b. The two image projection systems 501a and 501b can be any of the image projection systems described herein.

[0073] Thus, visible light projections, such as RGB projections, can be projected onto a user's eyes according to pre-programmed scanning patterns, with RGB light pulses following these patterns. These pre-programmed scanning patterns can be implemented by the respective MEMS mirrors of the two image projection systems, 501a and 501b. The two image projection systems, 501a and 501b, can be configured to project stereoscopic images, one for the left eye and one for the right eye.

[0074] As stated above, Fig. 5 is provided as an example. Other examples may differ from what is provided in relation to Fig. 5 is described.

[0075] The following provides an overview of some aspects of the present revelation: Aspect 1: An image projection system comprising: a light source configured to produce light rays corresponding to an image; a layer stack defining an internal cavity, the layer stack comprising: a first glass layer; a first semiconductor crystal layer arranged on the first glass layer; a second semiconductor crystal layer arranged on the first semiconductor crystal layer; and a second glass layer arranged on the second semiconductor crystal layer, wherein the inner surfaces of the first glass layer, the first semiconductor crystal layer, the second semiconductor crystal layer, and the second glass layer define the inner cavity; and a mirror of a microelectromechanical system (MEMS) arranged in the inner cavity and suspended from the first semiconductor crystal layer, wherein the second semiconductor crystal layer comprises a first inner inclined surface and a second inner inclined surface optically coupled to the first inner inclined surface, the first inner inclined surface and the second inner inclined surface defining a section of the inner cavity.wherein the first inner inclined surface is configured to receive the light rays from the light source and direct the light rays towards the second inner inclined surface, wherein the second inner inclined surface is configured to receive the light rays from the first inner inclined surface and direct the light rays towards the MEMS mirror, and wherein the MEMS mirror is configured to direct the light rays to render the image. Aspect 2: The image projection system according to Aspect 1, further comprising: an output waveguide arranged on the second glass layer and configured to receive the light beams from the MEMS mirror and to direct the light beams towards the eye of a user. Aspect 3: The image projection system according to Aspect 2, further comprising: a waveguide grid coupled to the output waveguide, the waveguide grid being configured to receive the light beams from the MEMS mirror and to couple the light beams into the output waveguide. Aspect 4: The image projection system according to Aspect 2, wherein the image projection system is a portable image projection system comprising a spectacle lens, and wherein the output waveguide is the spectacle lens or is optically coupled to the spectacle lens. Aspect 5: The image projection system according to one of aspects 1-4, wherein the first internal oblique surface and the second internal oblique surface are crystallographic surfaces, wherein the first internal oblique surface extends at a first angle of 45° or 54.74°, and wherein the second internal oblique surface extends at a second angle of 45° or 54.74°. Aspect 6: The image projection system according to one of aspects 1-5, wherein the first semiconductor crystal layer and the second semiconductor crystal layer are silicon crystal layers. Aspect 7: The image projection system according to any of aspects 1-6, further comprising: coupling optics configured to couple the light rays into the inner cavity through the first glass layer, wherein the light source is coupled to the first glass layer opposite the first semiconductor crystal layer, and wherein the first inner inclined surface is configured to receive the light rays from the coupling optics. Aspect 8: The image projection system according to aspect 7, wherein the layer stack is configured such that the light rays are coupled into the inner cavity through the first glass layer and coupled out of the inner cavity through the second glass layer. Aspect 9: The image projection system according to one of aspects 1-8, further comprising: coupling optics configured to couple the light rays into the inner cavity through the second glass layer, and wherein the first inner inclined surface is configured to receive the light rays from the coupling optics. Aspect 10: The image projection system according to Aspect 9, further comprising: an output waveguide arranged on the second glass layer and configured to receive the light beams from the MEMS mirror and to direct the light beams towards one eye of a user, the light source being coupled to the output waveguide opposite the second glass layer. Aspect 11: The image projection system according to Aspect 9, wherein the layer stack is configured such that the light rays are coupled into the inner cavity through the second glass layer and coupled out of the inner cavity through the second glass layer. Aspect 12: The image projection system according to one of aspects 1-11, wherein the first semiconductor crystal layer and the second semiconductor crystal layer are connected by anodic bonding, glass frit bonding or fusion bonding. Aspect 13: An image projection system comprising: a light source configured to produce light beams corresponding to an image; a stack of layers defining an inner cavity, the stack of layers comprising: a first glass layer; a first semiconductor crystal layer arranged on top of the first glass layer; a second semiconductor crystal layer arranged on top of the first semiconductor crystal layer; and a second glass layer arranged on top of the second semiconductor crystal layer, the inner surfaces of the first glass layer, the first semiconductor crystal layer, the second semiconductor crystal layer, and the second glass layer defining the inner cavity; a mirror of a microelectromechanical system (MEMS) arranged in the inner cavity and suspended from the first semiconductor crystal layer;a first grating arranged on the first glass layer within the inner cavity at an entrance side of the inner cavity; and a deflection element arranged within the inner cavity at an exit side of the inner cavity, wherein the deflection element is optically coupled to the first grating, the first grating being configured to receive the light rays from the light source and direct the light rays towards the deflection element, the deflection element being configured to receive the light rays from the first grating and direct the light rays towards the MEMS mirror, and the MEMS mirror being configured to direct the light rays to render the image. Aspect 14: The image projection system according to Aspect 13, further comprising: an output waveguide arranged on the second glass layer and configured to receive the light beams from the MEMS mirror and to direct the light beams towards the eye of a user. Aspect 15: The image projection system according to Aspect 14, further comprising: a waveguide grid coupled to the output waveguide, the waveguide grid being configured to receive the light beams from the MEMS mirror and to couple the light beams into the output waveguide. Aspect 16: The image projection system according to Aspect 14, further comprising: a light-blocking layer arranged above the deflection element to prevent light from escaping into the output waveguide, wherein the light-blocking layer is arranged between the deflection element and the output waveguide. Aspect 17: The image projection system according to one of aspects 13-16, wherein the deflecting element is a second grid or a reflective element. Aspect 18: The image projection system according to one of aspects 13-17, wherein the deflection element is arranged on an inner surface of the second glass layer or on an inner surface of the second semiconductor crystal layer. Aspect 19: The image projection system according to one of Aspects 13-18, further comprising: coupling optics configured to couple the light rays into the inner cavity through the first glass layer, wherein the light source is coupled to the first glass layer opposite the first semiconductor crystal layer, and wherein the first grating is configured to receive the light rays from the coupling optics. Aspect 20: The image projection system according to Aspect 19, wherein the layer stack is configured such that the light rays are coupled into the inner cavity through the first glass layer and coupled out of the inner cavity through the second glass layer. Aspect 21: An image projection system comprising: a light source configured to produce light beams corresponding to an image; a stack of layers defining an inner cavity, the stack of layers comprising: a first glass layer; a first semiconductor crystal layer arranged on top of the first glass layer; a second semiconductor crystal layer arranged on top of the first semiconductor crystal layer; and a second glass layer arranged on top of the second semiconductor crystal layer, the inner surfaces of the first glass layer, the first semiconductor crystal layer, the second semiconductor crystal layer, and the second glass layer defining the inner cavity; a mirror of a microelectromechanical system (MEMS) arranged in the inner cavity and suspended from the first semiconductor crystal layer;A coupling optic configured to couple the light rays into the inner cavity through the first glass layer; and a deflection element arranged inside the inner cavity at an exit side of the inner cavity, wherein the deflection element is optically coupled to the coupling optic, the coupling optic being configured to receive the light rays from the light source and direct the light rays towards the deflection element, the deflection element being configured to receive the light rays from the coupling optic and direct the light rays towards the MEMS mirror, and the MEMS mirror being configured to direct the light rays to render the image. Aspect 22: The image projection system according to Aspect 21, further comprising: an output waveguide arranged on the second glass layer and configured to receive the light beams from the MEMS mirror and to direct the light beams towards the eye of a user. Aspect 23: The image projection system according to Aspect 22, further comprising: a waveguide grid coupled to the output waveguide, the waveguide grid being configured to receive the light beams from the MEMS mirror and to couple the light beams into the output waveguide. Aspect 24: The image projection system according to one of aspects 21-23, wherein the deflecting element is a grid or a reflective element. Aspect 25: The image projection system according to one of aspects 21-24, wherein the deflection element is arranged on an inner surface of the second glass layer or on an inner surface of the second semiconductor crystal layer. Aspect 26: The image projection system according to one of aspects 21-25, wherein the layer stack is configured such that the light rays are coupled into the inner cavity through the first glass layer and coupled out of the inner cavity through the second glass layer. Aspect 27: An image projection system comprising: a light source configured to produce light beams corresponding to an image; a stack of layers defining an inner cavity, the stack of layers comprising: a first glass layer; a first semiconductor crystal layer arranged on top of the first glass layer; a second semiconductor crystal layer arranged on top of the first semiconductor crystal layer; and a second glass layer arranged on top of the second semiconductor crystal layer, the inner surfaces of the first glass layer, the first semiconductor crystal layer, the second semiconductor crystal layer, and the second glass layer defining the inner cavity; a mirror of a microelectromechanical system (MEMS) arranged in the inner cavity and suspended from the first semiconductor crystal layer;and a coupling optic configured to couple the light rays into the inner cavity through the second glass layer, wherein the coupling optic is configured to receive the light rays from the light source and direct the light rays into the inner cavity, and wherein the MEMS mirror is configured to direct the light rays to render the image. Aspect 28: The image projection system according to Aspect 27, further comprising: an output waveguide arranged on the second glass layer and configured to receive the light beams from the MEMS mirror and to direct the light beams towards the eye of a user. Aspect 29: The image projection system according to one of aspects 27-28, wherein the layer stack is configured such that the light rays are coupled into the inner cavity through the second glass layer and coupled out of the inner cavity through the second glass layer. Aspect 30: The image projection system according to one of Aspects 27-29, further comprising: a grating arranged on the second glass layer within the inner cavity, wherein the coupling optics are configured to direct the light rays towards the grating, and wherein the grating is configured to receive the light rays from the coupling optics and direct the light rays towards the MEMS mirror. Aspect 31: A system that is configured to perform one or more operations listed in one or more of Aspects 1-30. Aspect 32: A device comprising means for carrying out one or more operations listed in one or more of Aspects 1-30. Aspect 33: A non-volatile, computer-readable medium storing a set of instructions, wherein the set of instructions comprises one or more instructions which, when executed by a device, cause the device to perform one or more operations listed in one or more of Aspects 1-30. Aspect 34: A computer program product comprising instructions or code for performing one or more operations listed in one or more of Aspects 1-30.

[0076] The foregoing disclosure provides illustration and description but is not intended to be exhaustive or to restrict the implementations to the exact form disclosed. Modifications and variations are possible in light of the foregoing disclosure or may be derived from the execution of the implementations.

[0077] Although the implementations described herein refer, for example, to MEMS devices with a mirror, it is understood that other implementations may involve optical devices other than MEMS mirror devices or other MEMS oscillation structures. While some aspects have been described in relation to a device, it is also clear that these aspects constitute a description of the corresponding process, where a block or device corresponds to a process step or a feature of a process step. Similarly, aspects described in relation to a process step also constitute a description of a corresponding block, element, or feature of a corresponding device.Some or all of the process steps can be performed by (or using) a hardware device, such as a microprocessor, a programmable computer, or an electronic circuit.

[0078] Some implementations can be described herein in connection with thresholds. As used herein, "meeting" a threshold may refer to a value that is greater than the threshold, more than the threshold, higher than the threshold, greater than or equal to the threshold, less than the threshold, less than the threshold, lower than the threshold, less than or equal to the threshold, equal to the threshold, or the like.

[0079] As used herein, the term "component" is to be understood broadly as hardware, firmware, or a combination of hardware and software. Systems and / or procedures described herein may be implemented in various forms of hardware, firmware, or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and / or procedures does not restrict the implementations. Thus, the operation and behavior of the systems and / or procedures are described herein without reference to specific software code—it is understood that software and hardware may be designed to implement the systems and / or procedures based on the description herein.

[0080] Each of the processing components can be implemented as a central processing unit (CPU) or another type of processor that reads and executes a software program from a non-volatile, computer-readable recording medium, such as a hard disk or semiconductor storage device. For example, instructions can be executed by one or more processors, such as one or more CPUs, digital signal processors (DSPs), general-purpose microprocessors, application-specific integrated circuits (ASICs), field-programmable logic arrays (FPLAs), programmable logic controllers (PLCS), or other equivalent integrated or discrete logic circuits. Accordingly, the term "processor," as used herein, refers to any of the foregoing structures or any other structure suitable for implementing the techniques described herein.Software can be stored on a non-volatile, computer-readable medium such that the non-volatile, computer-readable medium contains program code or a program algorithm stored on it which, when executed, causes the processor, via a computer program, to perform the steps of a procedure.

[0081] A controller incorporating hardware can also perform one or more of the techniques described in this disclosure. A controller incorporating one or more processors can use electrical signals and digital algorithms to perform its acquisition, analysis, and control functions, which may further include correction functions. Such hardware, software, and firmware can be implemented within the same device or within separate devices to support the various techniques described in this disclosure.

[0082] A signal processing circuit and / or a signal conditioning circuit can receive one or more signals (e.g., measurement signals) from one or more components in the form of raw measurement data and can derive further information from the measurement signal. "Signal conditioning," as used herein, refers to manipulating an analog signal in such a way that the signal meets the requirements of a subsequent processing stage. Signal conditioning may include analog-to-digital conversion (e.g., via an analog-to-digital converter), amplification, filtering, conversion, biasing, range matching, isolation, and any other processes necessary to make a signal suitable for processing after conditioning.

[0083] Even if certain combinations of features are listed in the claims and / or disclosed in the patent specification, these combinations are not intended to limit the disclosure of implementations described herein. Many of these features can be combined in ways not expressly listed in the claims and / or disclosed in the patent specification. For example, the disclosure includes each dependent claim in a set of claims in combination with each other individual claim in that set of claims and each combination of several claims in that set of claims. As used herein, a phrase referring to "at least one of" a list of elements refers to each combination of those elements, including individual elements. As an example, "at least one of: a, b, or c" is intended to cover a, b, c, a and b, a and c, b and c, and a, b, and c, as well as each combination with multiples of the same element (e.g.,a + a, a + a + a, a + aa + b, a + a + c, a + b + b, a + c + c, b + b, b + b + b, b + b + c, c + c and c + c + c or any other order of a, b and c).

[0084] Furthermore, it is understood that the disclosure of multiple acts or functions in the patent specification or in the claims may not be interpreted as being in a specific order. Therefore, the disclosure of multiple acts or functions does not restrict them to a particular order unless such acts or functions are not interchangeable for technical reasons. Moreover, in some implementations, a single act may comprise or be broken down into multiple sub-acts. Such sub-acts may be included and form part of the disclosure of that single act unless they are expressly excluded.

[0085] No element, action, or instruction used herein should be construed as critical or essential unless expressly described as such. Furthermore, as used herein, the article "the" should include one or more elements referred to in conjunction with the article "the" and may be used interchangeably with "the one or the several." Also, as used herein, the terms "has," "have," "have," or the like should be open terms that do not restrict any element they modify (e.g., an element that has A may also have B). Furthermore, the phrase "based on" should mean "at least partly based on" unless expressly stated otherwise. As used herein, the term "several" may be replaced by "a multitude of" and vice versa.Furthermore, as used herein, the term “or” is to be inclusive when used in a series and can be used interchangeably with “and / or” unless expressly stated otherwise (e.g. when used in combination with “either” or “only one of”).

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