Light folding projector

Abstract

This disclosure relates to a light-folding projector. An apparatus may include a light-folding projector comprising an infrared (IR) light emitter and a light-folding element. The light-folding element may receive IR light emitted from the IR light emitter and fold the IR light once or multiple times to guide the IR light through the light-folding element to exit the apparatus into the environment. The apparatus may also include a detector that can use the IR light from the light-folding projector to detect and / or identify objects in the environment, and a forward-facing camera for capturing an image of the environment in front of the apparatus.

Description

Background Art

[0001] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 152550, filed on February 23, 2021, which is incorporated herein by reference in its entirety. Technical Field

[0002] This disclosure relates in general to mobile multipurpose devices, and more specifically to mobile multipurpose devices including light-folding projectors.

[0003] Related technical descriptions

[0004] Mobile multi-purpose devices such as smartphones, tablets, and / or tablets are now considered necessities. They integrate a variety of functions in a small package, providing great ease of use. Sometimes, mobile multi-purpose devices may include a screen "notch," such as a small cutout, at the top of the display. The notch provides edge-to-edge housing for imaging and sensing components within the display, such as a front-facing camera (e.g., a selfie camera), an infrared (IR) projector, and an IR detector. While the notch allows for a reduced or eliminated bezel, it still limits the total display area of ​​the device. Therefore, it is desirable to reduce the footprint of the imaging and sensing components to maximize the display area of ​​the device. Attached Figure Description

[0005] Figures 1A to 1C This is a simplified schematic diagram illustrating an exemplary design of the imaging and sensing components of a device according to some implementation schemes.

[0006] Figures 2A to 2C An exemplary light-folding projector is shown according to some implementation schemes.

[0007] Figures 3A to 3D This is a simplified schematic diagram illustrating an exemplary design of the optical components of a light-folding projector according to some embodiments.

[0008] Figures 4A to 4C An exemplary light-folding projector is shown according to some implementation schemes.

[0009] Figures 5A to 5C An exemplary light-folding projector is shown according to some implementation schemes.

[0010] Figures 6A to 6C An exemplary light-folding projector is shown according to some implementation schemes.

[0011] 7A to 7C An exemplary light-folding projector is shown according to some implementation schemes.

[0012] Figures 8A to 8CAn exemplary light-folding projector is shown according to some implementation schemes.

[0013] Figures 9A to 9C An exemplary light-folding projector is shown according to some implementation schemes.

[0014] Figure 10 Exemplary parameters of an exemplary light-folding projector according to some implementation schemes are shown.

[0015] Figure 11 This is a high-level flowchart illustrating exemplary techniques and methods for projecting IR light using optical folding elements according to some implementations.

[0016] Figure 12 This is a high-level flowchart illustrating exemplary techniques and methods for implementing object detection and / or identification according to some implementation schemes.

[0017] Figure 13 A schematic diagram of an exemplary device that may include a light-folding projector according to some embodiments is shown.

[0018] Figure 14 A schematic block diagram of an exemplary computer system that may include a light-folding projector according to some embodiments is shown.

[0019] This specification includes references to "one embodiment" or "implementation". The use of the phrase "in one embodiment" or "in an embodiment" does not necessarily refer to the same embodiment. Specific features, structures, or characteristics may be combined in any suitable manner consistent with this disclosure.

[0020] The term "comprising" is open-ended. As used in the appended claims, it does not exclude additional structures or steps. Consider the following cited claim: "An apparatus comprising one or more processor units..." Such claims do not exclude the inclusion of additional components (e.g., network interface units, graphics circuitry, etc.).

[0021] "Configured as" refers to various units, circuits, or other components that can be described or stated as being "configured as" to perform one or more tasks. In such a context, "configured as" is used to imply a structure (e.g., a circuit) that includes a unit / circuit / component that performs one or more tasks during operation. Thus, a unit / circuit / component is allegedly configured to perform the task even when the specified unit / circuit / component is currently inoperable (e.g., not switched on). Units / circuits / components used with the language "configured as" include hardware—e.g., circuits, memory storing program instructions that can be executed to perform the operation, etc. Referring to a unit / circuit / component as being "configured as" to perform one or more tasks is explicitly intended to not invoke 35 USC §112(f) for that unit / circuit / component. Furthermore, "configured as" can include general structures (e.g., general-purpose circuits) manipulated by software and / or firmware (e.g., FPGAs or general-purpose processors executing software) in a manner capable of performing one or more tasks to be solved. "Configured to" may also include adjusting the manufacturing process (e.g., a semiconductor manufacturing facility) to manufacture equipment (e.g., an integrated circuit) suitable for performing one or more tasks.

[0022] "First," "second," etc. As used herein, these terms serve as labels for the nouns preceding them and do not imply any type of ordering (e.g., spatial, temporal, logical, etc.). For example, a buffer circuit may be described herein as performing write operations on a "first" value and a "second" value. The terms "first" and "second" do not necessarily imply that the first value must be written before the second value.

[0023] "Based on." As used herein, this term describes one or more factors that influence the determination. This term does not exclude additional factors influencing the determination. That is, the determination may be based solely on these factors or at least partially on them. Consider the phrase "A is determined based on B." In this case, B is the factor influencing the determination of A, and such phrases do not exclude the possibility that the determination of A may also be based on C. In other instances, A may be determined solely on B.

[0024] It will also be understood that while the terms “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are merely used to distinguish one element from another. For example, without departing from the intended scope, a first contact may be referred to as a second contact, and similarly, a second contact may be referred to as a first contact. Both the first contact and the second contact are contacts, but they are not the same contact.

[0025] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the specification and appended claims, the singular forms “a,” “an,” and “the” are intended to also cover the plural forms unless the context otherwise expressly indicates otherwise. It will also be understood that the term “and / or” as used herein refers to and covers any and all possible combinations of one or more of the items listed in connection with the description. It will also be understood that the terms “comprising” and / or “including” as used in this specification specify the presence of the 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.

[0026] As used herein, depending on the context, the term "if" can be interpreted as meaning "when..." or "in response to determination" or "in response to detection". Similarly, depending on the context, the phrase "if it is determined..." or "if [the stated condition or event] is detected" can be interpreted as meaning "when it is determined..." or "in response to determination..." or "when [the stated condition or event] is detected" or "in response to detection". Detailed Implementation

[0027] The various embodiments described herein relate to a device that uses a light-folding projector to reduce the footprint of components and maximize the display area of ​​the device. In some embodiments, the device may include several imaging and sensing components, such as a forward-facing camera, an IR projector, and an IR detector (hereinafter referred to as "imaging and sensing components"). The IR projector may include an IR light emitter and a light-folding element. In some embodiments, the light-folding element may include a multi-surface prism. The light-folding element may receive IR light emitted from the IR light emitter, fold the IR light (e.g., change the transmission direction of the IR light) once or multiple times, and guide it through the light-folding element to project the IR light onto the external environment through a projector aperture. The IR detector (e.g., an IR camera) may receive IR light reflected from objects in the environment (e.g., a user's face) through a detector aperture, and provide detection and / or identification (e.g., facial recognition) of objects in front of the device. The forward-facing camera, such as a fixed-focus or autofocus (AF) camera, may be used to capture images of objects in the environment in front of the device. In some embodiments, the device may be a mobile multi-purpose device, such as a smartphone, tablet computer, tablet computer, etc.

[0028] The use of light-folding projectors can reduce the footprint of imaging and sensing components in a device, thereby increasing the display area, such as in devices with bezels. In particular, the use of light-folding elements provides greater flexibility in positioning the IR light emitter relative to other components, such as IR detectors and forward-facing cameras. For example, because the light-folding element can alter the transmission direction of IR light, the IR light emitter is not necessarily limited to a specific mounting location. Instead, the IR light emitter can be placed in a location with less constrained space, and the light-folding element can be used to project IR light in a specific direction. This reduces the overall size of the imaging and sensing components, thus reducing the size of the notch used to hold the imaging and sensing components and increasing the display area of ​​the device. In some embodiments, the light-folding element can be at least partially positioned between the housing of the forward-facing camera and the closure of the device. For example, at least a portion of the light-folding element can be positioned between a portion of the forward-facing camera and the cover glass of the device.

[0029] In some embodiments, the device may include one or more lenses optically positioned between an IR light emitter and a light folding element, such that the one or more lenses allow IR light from the IR light emitter to pass through to the light folding element. The one or more lenses may provide refractive force to the light folding projector, enabling the light folding projector to focus the emitted IR light. This can improve the object detection and / or recognition performance of the device. In some embodiments, the one or more lenses may include at least one lens made of plastic (e.g., a plastic lens), glass (e.g., a glass lens), polycarbonate (e.g., a polycarbonate lens), or other optical materials. In some embodiments, the one or more lenses may include at least one wafer-level lens or wafer-grade lens. Wafer-level lenses are typically fabricated at the wafer level, for example, using wafer-level imprinting and / or wafer-level packaging. Using wafer-level optics, thousands of lenses can be fabricated simultaneously on a semiconductor wafer—significantly improving the efficiency of mass production. Furthermore, wafer-level optics can reduce the size of the lenses compared to other manufacturing processes. In some embodiments, the at least one wafer-level lens may be formed by bonding or mounting one or more plastic portions to a glass substrate.

[0030] In some embodiments, the light folding element itself may have refractive power to further enhance the IR focusing capability of the light folding projector. For example, the light folding element may include a refractive portion of the environment-facing front surface of a prism bonded to the light folding element. Alternatively, in some embodiments, the light folding element itself may not necessarily have refractive power, and the light folding projector may further include at least one refractive lens (e.g., a plastic, glass, or polycarbonate lens) that is separable from and positioned outside the front surface of the light folding element. The at least one lens allows IR light exiting the light folding element to pass through to the environment.

[0031] In some embodiments, the optical folding element may include a coating on one or more surfaces of the prism of the optical folding element. For example, the optical folding element may have a coating on the rear surface facing the IR light emitter. In some embodiments, the optical folding element may include a coating on the front surface facing the environment. In some embodiments, the coating may be designed to increase (1) the transmittance of IR light at relatively low incident angles and / or (2) the reflectance of IR light at relatively high incident angles at the corresponding surfaces. As described below, the coating can improve the IR light guiding performance of the optical folding element.

[0032] Figures 1A to 1C This is a simplified schematic diagram illustrating an example design of the imaging and sensing components of a device according to some implementation schemes. Figures 1A to 1C Partial top views and partial cross-sectional views of the equipment are shown respectively. For illustrative purposes, only relevant components are depicted in the figures. Figures 1A to 1C A global optical coordinate system defined by the XYZ axes is also shown, where the Z-axis corresponds to the optical axis of camera 105, and the XY axes are orthogonal to the Z-axis. Figure 1A In this device 100, imaging and sensing components may be included, such as a forward-facing camera 105, an IR light emitter 110, a light folding element 115, and an IR detector 120. In this disclosure, the IR light emitter 110 and the light folding element 115 may collectively be referred to as a light folding projector. Figure 1AAs shown, device 100 may also include a cover glass, which may further include a black mask to conceal imaging and sensing components beneath the cover glass. A light-folding projector and an IR detector 120 may operate together to implement object detection and / or recognition functions, while a forward-facing camera 105 may be used to capture images of objects in front of device 100. For example, the light-folding projector may project IR light into the environment in front of device 110 through a projector aperture, and the IR detector 120 may receive IR light reflected from objects in the environment through a detector aperture to achieve object detection and / or recognition. Camera 105 may be a forward-facing camera that can capture images of objects in the environment based on visible light received through a camera aperture. In some embodiments, the forward-facing camera 105 may be a fixed-focus camera with a constant focal length. In some embodiments, the forward-facing camera 105 may be an autofocus camera whose focal length may be automatically adjusted, for example, using an actuator. In this example, the projector aperture, detector aperture, and camera aperture are illustrated as being aligned approximately in a straight line within a notch. Note that this is merely an example for illustrative purposes. The apertures are not limited to a straight line position, but can be placed in one of various locations. In addition, because visible light can pass through the cover glass and IR light can pass through the cover glass and the black mask, the projector aperture, detector aperture, and camera aperture do not necessarily refer to physical holes or openings on the cover glass or black mask, but rather to a portion of the cover glass or black mask through which visible and IR light are transmitted.

[0033] The light folding element 115 can fold the IR light generated from the IR emitter 110 and change its transmission direction once or multiple times within the light folding element 115 to project the IR light out of the device 100 in a specific direction. This frees up the positioning of the IR emitter 110. For example, the IR emitter 110 is not necessarily limited to being mounted directly below the projector aperture. Instead, the IR emitter 110 can be displaced relative to the projector aperture, and the light folding element 115 is used to fold the IR light so that it is still projected through the projector aperture. For example, in Figure 1A In this configuration, camera 105 and IR detector 120 may be laterally positioned relative to each other below their respective apertures (e.g., along the X-axis). IR emitter 110 may not necessarily be aligned with camera 105 and IR detector 120, but may be shifted to at least partially overlap with IR detector 120 (e.g., along the Y-axis), as... Figure 1A As shown. Therefore, the camera aperture, projector aperture, and detector aperture can still be aligned with each other, while the IR emitter 110 can be offset relative to the camera 105 and the IR detector 120. Furthermore, the light folding element 115 can utilize readily available space within the device 100, such as the space between the housing of the camera 105 and the housing of the device 100. In this example, at least a portion of the light folding element 115 can be positioned between a portion of the camera 105 and the cover glass of the device 100, such as... Figure 1AThe cross-sectional view is shown in the figure. This also avoids interference between (1) the IR light transmitted from the IR light emitter 110 through the light folding element 115 into the environment and (2) the IR light reflected from the environment into the IR detector 120. In other words, the reflected IR light can be received by the IR detector 120 without passing through the light folding element 115. The overlapping spatial arrangement reduces the footprint of these imaging and sensing components.

[0034] Figure 1B This demonstrates the reduction in the footprint of imaging and sensing components through the use of a light-folding projector (with a light-folding element). Figure 1B In the middle, device 140 does not include a light-folding projector, and... Figure 1A The device 100 differs from the device 140. Therefore, the forward-facing camera 105, IR transmitter 110, and IR detector 120 can not spatially overlap each other, but are positioned laterally (e.g., along the X-axis). This increases the footprint of the imaging and sensing components. For example, as reflected in the size of the notch, the length of the notch can increase from L1 of device 100 to L2 of device 140. In other words, Figure 1A The light-folding projector in the middle can reduce the size of the notch and increase the display area of ​​the device 100.

[0035] Furthermore, the reduced footprint frees up space within the device, providing flexibility to increase component size, arrange components within the device, and / or reduce the overall size of the device. For example, in some embodiments, the device can increase the size of the camera and / or IR detector to accommodate larger image sensors and / or optics, add additional functionality (e.g., autofocus), etc. Figure 1C As shown, according to some implementation schemes, device 150 can use a ratio Figure 1B The front-facing camera 105 is larger than the front-facing camera 155. However, due to the space-saving design of the light-folding projector, this does not necessarily sacrifice the size of the display area of ​​the device 150. For example, the length of the notch in the device 150 with the light-folding projector (e.g., L3) can still be smaller than or close to the length of the notch in the device 140 without the light-folding projector (e.g., L2).

[0036] It should be noted that, for illustrative purposes, this disclosure uses IR light as an example to describe object detection and / or identification. In some embodiments, the device may use light in a different wavelength spectrum to perform object detection and / or identification. Additionally, for illustrative purposes, Figures 1A to 1C Only the forward-facing camera, IR light emitter, light folding element, and IR detector are shown. In some embodiments, the device may include one or more additional imaging and sensing components behind the notch.

[0037] Figures 2A to 2CAn exemplary light-folding projector according to some embodiments is shown. In this example, the light-folding projector 200 may include an IR light emitter 205 and a light-folding element 210. The IR light emitter 205 may emit IR light. The light-folding element 210 may receive IR light from the IR light emitter, fold and guide the IR light through the light-folding element 210 into the environment. For example, the light-folding element 210 may reflect IR light at a surface to change the transmission direction of the IR light. In some embodiments, the light-folding element 210 may fold IR light once or multiple times. For example, in some embodiments, the light-folding element 210 may include a parallelogram prism, which may be made of plastic, glass or other suitable optical materials. In some embodiments, the prism may be a single-piece element, such as a monolithic solid prism or a single-piece prism with an internal cavity. In some embodiments, the prism may be formed by joining several individual pieces together (e.g., a rectangular prism joined with two triangular prisms). Figure 2A As shown, the prism of the light folding element 210 may include a first surface S1 parallel to the third surface S3 and a second surface S2 parallel to the fourth surface S4. In some embodiments, the light folding element 210 may be arranged relative to the IR light emitter 205 such that the first surface S1 faces the IR light emitter 205, while the third surface S3 faces the environment. For illustrative purposes, the first surface S1 facing the IR light emitter is also referred to as the rear surface, and the third surface S3 facing the environment is also referred to as the front surface. Note that, for illustrative purposes, Figure 2A A prism is shown to perform light folding. In some embodiments, the light folding element 210 may use other suitable optical components, such as one or more mirrors, to fold IR light.

[0038] In this example, such as Figure 2A As shown, the optical folding element 210 can transmit IR light emitted from the IR emitter 205 through the first surface S1 of the prism into the optical folding element 210. At least some of the IR light can reach the second surface S2 of the prism of the optical folding element 210 and is then reflected at the second surface, such as... Figure 2A As indicated by the edge in the middle, for example, the IR light is folded once. At least some of the IR light reflected from the second surface S2 can bounce back to the first surface S1, such as... Figure 2AThe edges are indicated in the diagram. When the incident angle of the IR light is close to or greater than the critical angle of the prism, total internal reflection (TIR) ​​can occur, and the IR light can be reflected at the first surface S1, for example, the IR light is folded twice. Next, at least some of the IR light reflected from the first surface S1 can be transmitted to the third surface S3 of the prism of the light folding element 210 and reflected at the third surface under TIR, for example, the IR light is folded three times. Finally, at least some of the IR light reflected from the third surface S3 can reach the fourth surface S4 of the prism, be reflected at the fourth surface S4 under TIR, and leave the prism of the light folding element 210 through the third surface S3 to the environment – ​​for example, the light is folded four times. Therefore, in this example, at least some of the IR light from the IR emitter 205 can be folded four times by the light folding element 210. It should be noted that in some embodiments, the light folding element 210 may include a prism of another geometry, and thus the IR light can be folded fewer or more times.

[0039] In some embodiments, the light folding projector 200 may further include one or more lenses 215, 220, and 225. Lenses 215-225 may be optically positioned between the IR light emitter 205 and the light folding element 210 such that these lenses can pass IR light emitted from the IR light emitter 205 to the light folding element 210. In some embodiments, lenses 215-225 may have a refractive power, such as the degree to which the lens converges IR light (e.g., corresponding to a positive refractive power) or disperses IR light (e.g., corresponding to a negative refractive power), such that the light folding projector 200 has the ability to focus the emitted IR light.

[0040] In some embodiments, the light folding element 210 itself may have refractive power to further enhance the IR focusing capability of the light folding projector 200. For example, the light folding element 210 may include a portion 230 that may have refractive power and be bonded to the third surface S3 of the environment-facing light folding element 210. In this way, IR light leaving the prism of the light folding element 210 can further pass through the refractive portion to exit into the environment. Alternatively, in some embodiments, the light folding element 210 itself may not necessarily have refractive power, and the light folding projector 200 may further include at least one lens (e.g., a lens with refractive power) that is separable from and positioned close to the third surface S3 of the light folding element 210. Figure 3C (As shown in the diagram). The at least one lens can pass through and further focus the IR light exiting from the light folding element 210.

[0041] In some embodiments, the light folding element 210 can be formed using various materials and methods. For example, when the light folding element 210 includes a refractive force portion 230, portion 230 can be made of plastic, and the remaining portions of the light folding element 210 (e.g., a parallelogram prism) can be made of glass. The two portions can then be bonded together, for example, using adhesive, to form the light folding element 210 with refractive force. Alternatively, the light folding element 210 and the prism of portion 230 can be made of the same material (e.g., plastic or glass), wherein the two portions can be formed separately and subsequently bonded together, or they can be formed simultaneously together. In some embodiments, lenses 215-225 and / or at least one lens adjacent to the third surface S3 of the light folding element 210 can also be formed using various materials and methods. For example, one or more of the lenses can be made of plastic, glass, or polycarbonate. In some embodiments, one or more of the lenses can be wafer-grade lenses, for example, including one or more plastic portions bonded to a glass substrate.

[0042] In some embodiments, the light folding element 210 can be designed such that the acute angle between two adjacent surfaces of the prism (e.g., between the first surface S1 and the second surface S2 of the light folding element 210) is in the range of 25 degrees to 35 degrees (e.g., 25 ≤ prism angle ≤ 35 degrees). In some embodiments, the ratio between the thickness of the prism of the light folding element 210 and the total optical path length (TTL) of the light folding projector 200 can be in the range of 0.3 to 0.5 (e.g., 0.3 ≤ prism thickness / TTL ≤ 0.5). Figure 2AAs shown, the thickness and TTL are measured in a direction approximately parallel to the optical axis (or Z-axis) of lenses 215-225. For example, the thickness may refer to the distance between the first surface S1 (facing the IR light emitter 205) and the third surface S3 (facing the environment) of the prism of the light folding element 210. The TTL may correspond to the distance between the front surface of the IR light emitter 205 (facing the light folding element 210) and the front surface G1S1 of portion 230 (facing the environment) of the light folding element 210. In some embodiments, lenses 215-225 may have positive or negative refractive power. For example, in this example, group 1 (including the light folding element 210) may have positive refractive power, group 2 (including lens 225) may have negative refractive power, and group 3 (including lenses 215 and 220) may have positive refractive power. In some embodiments, the absolute values ​​of the refractive power of groups 1, 2, and 3 may have a relationship such that 0.2 ≤ (refractive power of group 1) / [(absolute value of refractive power of group 2) + (refractive power of group 3)] ≤ 0.6. In some embodiments, the ratio between the effective focal length (EFL) of the light-folding projector 200 and the thickness of the prism of the light-folding element 210 may be in the range of 2 to 4 (e.g., 2 ≤ (EFL of the light-folding projector) / prism thickness ≤ 4). In some embodiments, the effective focal length (EFL) of group 1 is related to the length of the prism of the light-folding element 210 (e.g., measured in a direction generally parallel to the X-axis, such as...). Figure 2A The ratio between (as shown) can be in the range of 0.8 to 1.2 (e.g., 0.8 ≤ (EFL of Group 1) / prism length ≤ 1.2).

[0043] Figures 2B to 2C Example values ​​for some parameters of the light-folding projector 200 are provided. For example, in Figure 2B In this context, k, A, B, C, and D refer to the parameters in the following equations used for the design of the aspherical surfaces of lenses 215-225 and the refractive power portion 230 (e.g., surfaces G3S1 and G3S2 of lens 215, G3S3 and G3S4 of lens 220, G2S1 and G2S2 of lens 225, and G1S1 of portion 230):

[0044]

[0045] Where z refers to the sag of the aspherical surface parallel to the optical axis of the lens, h is the radial distance from the optical axis, r is the radius of curvature, k is the conic constant, and A, B, C, and D refer to the 4th, 6th, 8th, and 10th order aspherical coefficients, respectively. Figure 2CIn this context, radius refers to the radial distance of the surface of the corresponding optical component (including lenses 215-225, optical folding element 210, and refractive force portion 230) relative to its own optical axis, and thickness refers to the travel distance in each segment of the optical path of the main IR ray transmitted from the IR emitter 205 through lenses 215-225 along the optical axis (or Z-axis) of lenses 215-225 (e.g., ...). Figure 2A (As shown), the angle refers to the incident angle of the main IR ray at the corresponding surface of the light folding element 210, and the refractive index and dispersion coefficient of the lens refer to the refractive index and dispersion coefficient of the individual optical components. For example, the radius on rows 2 to 7 corresponds to the radius of the surface of lens 215-225, while the thickness on rows 9 to 13 refers to the travel distance of the main IR light within the prism of the light folding element 210.

[0046] Figures 3A to 3D This is a simplified schematic diagram illustrating an exemplary design of the optics of a light-folding projector according to some embodiments. Figure 3A As shown, the light-folding projector 300 may include a light-folding element 305 and one or more lenses 310-315. In some embodiments, the light-folding element 305 may include a prism 302 (e.g., a parallelogram prism) and a portion 304 that can be bonded to the prism 302. As described above, in some embodiments, the prism 302 and the portion 304 may be made of different materials. For example, the prism 302 may be formed using glass, while the portion 304 may be made of plastic. The portion 304 may be bonded to the prism 302, for example, using adhesive. Alternatively, the prism 302 and the portion 304 may be made of the same material and may be formed simultaneously together, or first formed separately and then joined together.

[0047] In some implementations, prism 302 may not necessarily have refractive power, but part 304 may have refractive power (e.g., having a refractive force such as...). Figure 3A (The convex front surface is shown). Therefore, the light folding element 305 as a whole can have refractive power and be able to focus IR light. In some embodiments, lenses 310 and 315 can be optically arranged between an IR light emitter (not shown) and the light folding element 305, such that lenses 310 and 315 can pass IR light from the IR light emitter to the light folding element 305. As mentioned above, lenses 310 and 315 can include plastic lenses, glass lenses, polycarbonate lenses, or other types of optical lenses. In this example, lenses 310 and 315 can be wafer-grade lenses, each of which can include one or more plastic portions attached to a glass substrate. For example, lens 310 can include plastic portions 312 and 313 bonded to a glass substrate 311, while lens 315 can be formed by bonding plastic portions 317 and 318 to a glass substrate 316. The plastic portions 312 / 313 and 317 / 318 of lenses 310 and 315 can have refractive power, such as Figure 3A The geometry of medium plastics 312 / 313 and 317 / 318 is shown. Additionally, as... Figure 3A As shown, the light folding projector 300 can use the cylinder 320 as a mechanical support to hold the lenses 310 and 315. For example, the cylinder 320 may include internal threads, and the lenses 310 and 315 can be screwed into the cylinder 320 via the threads.

[0048] As described above, during the transmission of IR light, the first surface S1 and the third surface S3 of the prism 302 can each transmit IR light when the IR light has a relatively low angle of incidence and reflect IR light when the IR light has a relatively high angle of incidence. Therefore, in some embodiments, the optical folding element 305 may include a coating 306 at the first surface S1 and / or the third surface S3 to enhance the transmission and / or reflection of IR light at the corresponding surfaces. Figure 3B It shows Figure 3A An enlarged view of the circular area shown. Figure 3B In some embodiments, coating 306 may be immersed in the third surface S3 of the prism 302 facing the environment (e.g., at least covering the area between prism 302 and portion 304). In some embodiments, coating 306 may also be applied to the first surface S1 of the prism 302 facing lenses 310-315 and the IR light emitter. In some embodiments, coating 306 may increase the transmittance of IR light 308, which may have a relatively low angle of incidence (e.g., less than 15 degrees), and / or increase the reflectance of IR light 309, which may have a relatively high angle of incidence (e.g., more than 45 degrees), at the corresponding surfaces of prism 302. In some embodiments, materials such as titanium dioxide (TiO2) or silicon dioxide (SiO2) may be used to produce coating 306. Additionally, in some embodiments, the amount of retardation of coating 306 may be reduced to achieve a better transmittance wavefront of IR light after projection by the light-folding projector 300.

[0049] Figure 3C Another exemplary optical design for a light-folding projector is shown. In this example, the light-folding projector 330 may not necessarily include wafer-grade lenses 310 and 315, but rather plastic lenses 340 and 345. Furthermore, the light-folding element 335 of the light-folding projector 330 may include a prism 332 (e.g., a glass prism) and a portion 334 (e.g., a plastic lens). Therefore, the light-folding element 335 may still have a coating 336 at the third surface S3, but not at the first surface S1, because the optical properties of lenses 340 and 345 are now different from those of wafer-grade lenses 310 and 315.

[0050] Figure 3DAnother exemplary optical design for a light-folding projector is shown. In this example, the light-folding projector 360 may include plastic lenses 375-380 and a light-folding element 365. Additionally, the light-folding projector 360 may include at least one lens 370, such as a plastic lens, which may be separated from the light-folding element 365 and positioned close to the environment-facing third surface S3. Therefore, lens 370 may allow light exiting from the light-folding element 365 to pass into the environment. In some embodiments, lens 370 may have refractive power. Figures 3A to 3C In contrast, because lens 370 is not part of the light folding element 365 and is not directly attached to the prism, the optical properties of lens 370 for IR light can differ from those of portion 304 (of light folding element 305) and portion 334 (of light folding element 335). Therefore, the light folding projector 360 may not necessarily include a coating on the third surface S3 of the light folding element 365. Similar to... Figure 3C The 360-degree folding projector may not necessarily use a coating on the first surface S1. It should be noted that... Figures 3A to 3D These are examples for illustrative purposes only. In some embodiments, wafer-grade lenses (e.g., wafer-grade lenses 310 and 315) or non-wafer-grade lenses (e.g., lenses 345 / 350 and 375 / 370), light-folding elements with or without refractive power (e.g., with directly bonded refractive power portions 304 / 334 or with a separate lens 370), and coatings (e.g., coatings 306 and 336) may be combined in other ways. Additionally, for illustrative purposes only, Figures 3A to 3D The diagram shows two lenses (e.g., lenses 310 and 315) near the rear surface of the light folding element facing the IR light emitter, and one lens (e.g., lens 370) near the front surface of the light folding element facing the environment. In some embodiments, the light folding projector may include fewer or more lenses near any one or both surfaces of the light folding element.

[0051] Figures 4 through 9 illustrate further exemplary light-folding projectors and associated design parameters according to some embodiments. As shown in Figures 4 through 9, in some embodiments, the light-folding projector may include various designs of lenses near the rear and / or front surfaces of the light-folding element. For example, in Figure 4A In this configuration, the light-folding projector 400 may have two lenses near the rear surface of the light-folding element (e.g., similar to Figure 3). By comparison, in Figure 5A In this light-folding projector 500, three lenses may be positioned near the rear surface (e.g., similar to Figure 2). Furthermore, as shown in Figures 4 through 9, the lenses may have different geometries, be made of different materials, and be manufactured using different methods. For example, Figure 4A The lens in the image can be a plastic lens, while... Figure 8A and Figure 9A The lens in the image is illustrated as a wafer-level lens. Additionally, as shown in Figures 4 through 9, the design of the light folding element can be varied in some embodiments. For example, in... Figure 4A , Figure 7A , Figure 8A and Figure 9A In this context, the optical folding element may include a refractive force portion—the optical folding element may possess refractive force. By comparison, in... Figure 5A and Figure 6A In this context, the light-folding element itself may not necessarily have refractive power, but the light-folding projector may further include separate lenses (e.g., similar to...). Figure 3D The lens 370 is located near the environmentally facing front surface of the light folding element. The exemplary parameters in Figures 4 through 9 also illustrate the differences.

[0052] Besides the differences, the examples in Figures 4 through 9 also share some similarities. For example, in some embodiments, the light folding element in Figures 4 through 9 may include a prism (e.g., a parallelogram prism) (e.g., similar to the light folding element 210 in Figure 2). In some embodiments, the acute angle between two adjacent surfaces of the prism (e.g., the angle between the first surface S1 and the third surface S3 of the prism as shown in Figures 4 through 9) may be in the range of 25 degrees to 35 degrees (e.g., 25 ≤ prism angle ≤ 35 degrees). Additionally, in some embodiments, the ratio between the thickness of the prism and the total optical path length (TTL) of the light folding projector may be in the range of 0.3 to 0.5 (e.g., 0.3 ≤ prism thickness / TTL ≤ 0.5). In some embodiments, the absolute values ​​of the refractive power of groups 1, 2, and 3 may have a relationship such that 0.2 ≤ (absolute value of the refractive power of group 1) / [(absolute value of the refractive power of group 2) + (absolute value of the refractive power of group 3)] ≤ 0.6. In some embodiments, the ratio between the effective focal length (EFL) of the light-folding projector and the thickness of the prism can be in the range of 2 to 4 (e.g., 2 ≤ (EFL of the light-folding projector) / prism thickness ≤ 4). In some embodiments, the effective focal length (EFL) of group 1 is related to the length of the prism (e.g., measured in a direction generally parallel to the X-axis, such as...). Figure 2A The ratio between (as shown) can be in the range of 0.8 to 1.2 (e.g., 0.8 ≤ (EFL of Group 1) / prism length ≤ 1.2). To further illustrate the differences and similarities, Figure 10 An overview of some design parameters is provided for the examples shown in Figures 2 and 4 through 9.

[0053] Figure 11 This is a high-level flowchart illustrating exemplary techniques and methods for projecting IR light using an optical folding element according to some embodiments. For illustrative purposes, this example assumes that the optical folding element comprises a parallelogram prism. Figure 11 As shown, in some embodiments, IR light emitted from the IR light emitter of the light-folding projector can pass through the first surface of the prism of the light-folding element (e.g., similar to...). Figure 2A The light is transmitted through the surface S1 of the prism into the light folding element, as shown in box 1105. In some embodiments, the light folding projector may further include one or more lenses optically positioned between the IR light emitter and the light folding element, such that the one or more lenses allow IR light from the IR light emitter to pass through to the light folding element (the first surface). As shown in box 1110, at least some of the IR light can pass through the second surface of the prism (e.g., similar to...). Figure 2A The IR light is reflected at surface S2 of the prism. As described above, reflection can occur when the angle of incidence of the IR light is close to or greater than the critical angle at the second surface of the prism. At least some of the IR light reflected from the second surface can bounce back to the first surface and be reflected again at the first surface of the prism, as shown in box 1115. At least some of the IR light reflected from the first surface can travel to the third surface of the prism (e.g., similar to...). Figure 2A The light is reflected at the third surface (S3) as shown in box 1120. At least some of the IR light reflected from the third surface can reach the fourth surface of the prism (e.g., similar to surface S4 in FIG. 2) and is reflected at the fourth surface to exit the prism as shown in box 1125. As described above, in some embodiments, the light folding element may also include a refractive force portion (e.g., Figure 2A In part 230), IR light passing through the fourth surface may enter the refractive force portion and then exit the light folding element from the refractive force portion. Alternatively, in some embodiments, the light folding projector may further include at least one separate lens positioned near the fourth surface of the prism, wherein the at least one separate lens may transmit the IR light exiting the light folding element to the environment.

[0054] Figure 12 This is a high-level flowchart illustrating exemplary techniques and methods for implementing object detection and / or identification according to some implementation schemes. For example... Figure 12 As shown, in some embodiments, IR light reflected from objects in the environment of the projector (which may be generated by a light-folding projector) can be transmitted through one or more lenses of an IR detector, as shown in box 1205. At least some of the IR light can pass through the lenses and be received at the image sensor of the IR detector, as shown in box 1210. An imaging signal (e.g., an electrical signal) generated from the image sensor based on the received IR light can be transmitted to a processor, which can detect and / or identify objects in the environment, as shown in box 1215. In some embodiments, the processor can create an image to enable object detection and / or identification.

[0055] Figure 13The embodiments shown may include (e.g., as described herein with respect to Figures 1 to 1) Figure 12 A schematic diagram of an exemplary device 1300 of the described light-folding projector. In some embodiments, device 1300 may be a mobile device and / or a multi-functional device. In various embodiments, device 1300 may be any of a variety of types of devices, including but not limited to: personal computer systems, desktop computers, laptops, notebook computers, tablet computers, all-in-one computers, tablet computers or netbooks, mainframe computers, handheld computers, workstations, network computers, cameras, set-top boxes, mobile devices, augmented reality (AR) and / or virtual reality (VR) headsets, consumer devices, video game controllers, handheld video game devices, application servers, storage devices, televisions, video recording equipment, peripherals (such as switches, modems, routers), or any type of computing or electronic device in general.

[0056] In some embodiments, device 1300 may include a display system 1302 (e.g., including a display and / or a touch-sensitive surface) and / or one or more cameras 1304. In some non-limiting embodiments, the display system 1302 and / or one or more forward-facing cameras 1304a may be disposed on the front of device 1300, for example, as shown in the image. Figure 13 As indicated. Additionally or alternatively, one or more rear-facing cameras 1304b may be disposed on the rear of the device 1300. In some embodiments including a plurality of cameras 1304, some or all of the cameras may be identical or similar to each other. Additionally or alternatively, some or all of the cameras may be different from each other. In various embodiments, the position and / or arrangement of the cameras 1304 may vary. Figure 13 Those shown.

[0057] Among other things, device 1300 may include memory 1306 (e.g., including operating system 1308 and / or application / program instructions 1310), one or more processors and / or controllers 1312 (e.g., including CPU, memory controller, display controller and / or camera controller, etc.) and / or one or more sensors 1316 (e.g., orientation sensor, proximity sensor and / or position sensor, etc.). In some embodiments, device 1300 may communicate with one or more other devices and / or services (such as computing device 1318, cloud service 1320, etc.) via one or more networks 1322. For example, device 1300 may include a network interface (e.g., network interface 1410) that enables device 1300 to transmit data to and receive data from network 1322. Additionally or alternatively, device 1300 may be able to communicate wirelessly with other devices using any of a variety of communication standards, protocols and / or technologies.

[0058] Figure 14 A schematic block diagram of an exemplary computing device according to some embodiments is shown. This exemplary computing device is referred to as computer system 1400, which may include or host devices having (e.g., as referred to herein with reference to Figures 1 to 1400) Figure 13 The aforementioned implementation of the light-folding projector device. Furthermore, the computer system 1400 can implement methods for controlling camera operation and / or performing image processing on images captured by the camera. In some implementations, device 1300 (referenced herein) Figure 13 The (described) may additionally or alternatively include some or all of the functional components of the computer system 1400 described herein.

[0059] Computer system 1400 may be configured to perform any or all of the embodiments described above. In different embodiments, computer system 1400 may be any of a variety of types of devices, including but not limited to: personal computer systems, desktop computers, laptops, notebook computers, tablet computers, all-in-one computers, tablet computers or netbooks, mainframe computers, handheld computers, workstations, network computers, cameras, set-top boxes, mobile devices, augmented reality (AR) and / or virtual reality (VR) headsets, consumer devices, video game controllers, handheld video game devices, application servers, storage devices, televisions, video recording equipment, peripheral devices (such as switches, modems, routers), or any type of computing or electronic device in general.

[0060] In the illustrated embodiment, computer system 1400 includes one or more processors 1402 coupled to system memory 1404 via input / output (I / O) interface 1406. Computer system 1400 also includes one or more cameras 1408 coupled to I / O interface 1406. Computer system 1400 also includes a network interface 1410 coupled to I / O interface 1406, and one or more input / output devices 1412, such as cursor control device 1414, keyboard 1416, and display 1418. In some cases, it is conceivable that an embodiment may be implemented using a single instance of computer system 1400, while in other embodiments, multiple such systems or multiple nodes constituting computer system 1400 may be configured to host different portions or instances of the embodiment. For example, in one embodiment, some elements may be implemented via one or more nodes of computer system 1400 that are different from those nodes implementing other elements.

[0061] In various embodiments, computer system 1400 may be a single-processor system including one processor 1402, or a multiprocessor system including several processors 1402 (e.g., two, four, eight, or another suitable number). Processor 1402 may be any suitable processor capable of executing instructions. For example, in various embodiments, processor 1402 may be a general-purpose or embedded processor implementing any of a variety of instruction set architectures (ISAs) (such as x86, PowerPC, SPARC, or MIPS ISA or any other suitable ISA). In a multiprocessor system, each processor in processor 1402 may, but is not required to, implement the same ISA.

[0062] System memory 1404 may be configured to store program instructions 1420 accessible to processor 1402. In various embodiments, system memory 1404 may be implemented using any suitable memory technology, such as static random access memory (SRAM), synchronous dynamic RAM (SDRAM), non-volatile / flash memory, or any other type of memory. Additionally, existing camera control data 1422 in memory 1404 may include any of the aforementioned information or data structures. In some embodiments, program instructions 1420 and / or data 1422 may be received, transmitted, or stored on a different type of computer-accessible medium or similar medium separate from system memory 1404 or computer system 1400. In various embodiments, some or all of the functions described herein may be implemented via such computer system 1400.

[0063] In one embodiment, I / O interface 1406 may be configured to coordinate I / O communication between processor 1402, system memory 1404, and any peripheral devices in the device, including network interface 1410 or other peripheral device interfaces such as input / output device 1412. In some embodiments, I / O interface 1406 may perform any necessary protocol, timing, or other data conversions to convert data signals from one component (e.g., system memory 1404) into a format suitable for use by another component (e.g., processor 1402). In some embodiments, I / O interface 1406 may include support for devices attached, for example, via various types of peripheral buses (e.g., variants of the Peripheral Component Interconnect (PCI) bus standard or the Universal Serial Bus (USB) standard). In some embodiments, the functionality of I / O interface 1406 may be divided among two or more separate components, such as a northbridge and a southbridge. Furthermore, in some embodiments, some or all of the functionality of I / O interface 1406 (such as an interface to system memory 1404) may be directly incorporated into processor 1402.

[0064] Network interface 1410 may be configured to allow data exchange between computer system 1400 and other devices (e.g., bearers or agent devices) attached to network 1424, or between nodes of computer system 1400. In various embodiments, network 1424 may include one or more networks, including but not limited to local area networks (LANs) (e.g., Ethernet or enterprise networks), wide area networks (WANs) (e.g., the Internet), wireless data networks, some other electronic data network, or some combination thereof. In various embodiments, network interface 1410 may support communication via wired or wireless general-purpose data networks (such as any suitable type of Ethernet network), for example; via telecommunications / telephone networks (such as analog voice networks or digital fiber optic communication networks); via storage area networks (such as Fibre Channel SANs), or via any other suitable type of network and / or protocol.

[0065] In some embodiments, input / output device 1412 may include one or more display terminals, keyboards, keypads, touchpads, scanning devices, voice or optical recognition devices, or any other device suitable for inputting or accessing data by one or more computer systems 1400. Multiple input / output devices 1412 may be present in computer system 1400 or distributed across various nodes of computer system 1400. In some embodiments, similar input / output devices may be separate from computer system 1400 and may interact with one or more nodes of computer system 1400 via wired or wireless connections (such as through network interface 1410).

[0066] Those skilled in the art will understand that computer system 900 is merely illustrative and not intended to limit the scope of embodiments. Specifically, computer systems and devices may include any combination of hardware or software capable of performing the indicated functions, including computers, network devices, internet devices, PDAs, wireless telephones, pagers, etc. Computer system 900 may also be connected to other devices not shown, or conversely, may operate as a stand-alone system. Furthermore, the functionality provided by the illustrated components may, in some embodiments, be combined into fewer components or distributed across additional components. Similarly, in some embodiments, the functionality of some of the illustrated components may not be provided, and / or other additional functions may be available.

[0067] Those skilled in the art will also recognize that, although various items are shown as being stored in memory or on storage devices during use, these items, or portions thereof, may be transferred between memory and other storage devices for memory management and data integrity purposes. Alternatively, in other embodiments, some or all of these software components may be executed in memory on another device and communicate with the illustrated computer system via inter-computer communication. Some or all of the system components or data structures may also be stored (e.g., as instructions or structured data) on a computer-accessible medium or portable article of manufacture for reading by a suitable drive, various examples of which are described above. In some embodiments, instructions stored on a computer-accessible medium separate from computer system 900 may be transmitted to computer system 900 via a transmission medium or signal (such as electrical, electromagnetic, or digital signals transmitted via communication media such as networks and / or wireless links). Various embodiments may also include receiving, transmitting, or storing instructions and / or data implemented according to the above description on a computer-accessible medium. Generally, computer-accessible media may include non-transitory computer-readable storage media or memory media, such as magnetic or optical media, like discs or DVD / CD-ROMs, and volatile or non-volatile media, such as RAM (e.g., SDRAM, DDR, RDRAM, SRAM, etc.), ROM, etc. In some embodiments, computer-accessible media may include transmission media or signals, such as electrical signals, electromagnetic signals, or digital signals transmitted via communication media such as networks and / or wireless links.

[0068] In various implementations, the methods described herein can be implemented in software, hardware, or a combination thereof. Furthermore, the order of the blocks of the method can be changed, and various elements can be added, reordered, combined, omitted, modified, etc. Various modifications and changes will be apparent to those skilled in the art who benefit from this disclosure. The various implementations described herein are intended to be illustrative and not restrictive. Many variations, modifications, additions, and improvements are possible. Thus, multiple examples may be provided for a component described herein as a single example. The boundaries between various components, operations, and data repositories are somewhat arbitrary, and specific operations are shown in the context of a particular exemplary configuration. Other allocations of functionality are contemplated, which may fall within the scope of the appended claims. Finally, the structures and functions of discrete components presented in exemplary configurations can be implemented as combined structures or components. These and other variations, modifications, additions, and improvements may fall within the scope of the implementations as defined in the following claims.

Claims

1. An apparatus, the apparatus comprising: A camera configured to capture images of objects in the environment based on visible light received through a camera aperture; Projector, the projector comprising: Infrared (IR) light emitter, the IR light emitter is configured to emit IR light; and A light folding element configured to receive the IR light and reflect the IR light once or multiple times to guide the IR light through the light folding element and the projector aperture into the environment, wherein at least a portion of the light folding element is positioned between a portion of the camera and the cover glass of the device; and A detector configured to detect or identify the object in the environment using IR light emitted from the projector, reflected by the object, and received through a detector aperture. The IR light emitter is displaced relative to the camera and the detector in a second direction perpendicular to a first direction in which the camera and the detector are arranged, so as to at least partially overlap with the detector in the second direction, wherein the first direction and the second direction form a plane perpendicular to the optical axis of the camera, and wherein the camera aperture, the projector aperture and the detector aperture are aligned in the first direction.

2. The device of claim 1, wherein the light folding element comprises a prism, the prism being configured to: The IR light is transmitted through the first surface of the prism and into the prism; At least some of the IR light passing through the first surface of the prism is reflected at the second surface of the prism; At least some of the IR light reflected from the second surface of the prism is reflected at the first surface of the prism; At least some of the IR light reflected from the first surface of the prism is reflected at the third surface of the prism; as well as At least some of the IR light reflected from the third surface of the prism is reflected at the fourth surface of the prism so that it passes through the third surface and exits the prism.

3. The device according to claim 2, wherein the prism is a parallelogram prism, and wherein the angle between the first surface and the second surface of the prism is in the range of 25 degrees and 35 degrees.

4. The device of claim 1, wherein the light folding element further includes a portion of a surface of the light folding element facing the environment, and wherein the portion is configured to have refractive power.

5. The device of claim 4, wherein the optical folding element further comprises a coating on the surface of the optical folding element facing the environment, and wherein the coating is configured to increase at least one of the transmission or reflection of the IR light at the surface of the optical folding element.

6. The device of claim 1 further comprises at least one lens positioned outside the light folding element and close to the surface of the light folding element facing the environment.

7. The device of claim 1, further comprising one or more lenses optically positioned between the IR light emitter and the light folding element such that the IR light emitted from the IR light emitter passes through the one or more lenses to the light folding element.

8. The device of claim 7, wherein the one or more lenses comprise at least one wafer-grade lens, the at least one wafer-grade lens comprising one or more plastic portions of a glass substrate attached to the at least one wafer-grade lens.

9. The device of claim 8, wherein the optical folding element further comprises a coating on the surface of the optical folding element facing the one or more lenses, and wherein the coating is configured to increase at least one of the transmission or reflection of the IR light at the surface of the optical folding element.

10. The device of claim 7, wherein the one or more lenses comprise at least one lens made of plastic.

11. The device of claim 1, further comprising a detector configured to detect or identify objects in the environment using the IR light from the projector.

12. The device of claim 1, wherein the camera is positioned facing the environment to which the IR light is projected.

13. An apparatus, said apparatus comprising: A camera configured to capture images of objects in the environment based on visible light received through a camera aperture; Projector, the projector comprising: Infrared (IR) light emitter, the IR light emitter is configured to emit IR light; and A light folding element configured to receive the IR light and reflect the IR light once or multiple times to guide the IR light through the light folding element and the projector aperture into the environment, wherein at least a portion of the light folding element is positioned between a portion of the camera and the cover glass of the device; and A detector configured to detect or identify the object in the environment using IR light reflected from the projector, reflected from the object, and received through a detector aperture. The IR light emitter is displaced relative to the camera and the detector in a second direction perpendicular to a first direction in which the camera and the detector are arranged, wherein the first direction and the second direction form a plane perpendicular to the optical axis of the camera, and wherein the camera aperture, the projector aperture and the detector aperture are aligned in the first direction.

14. The device of claim 13, wherein the light folding element comprises a prism, the prism being configured to: The IR light is transmitted through the first surface of the prism and into the prism; At least some of the IR light passing through the first surface of the prism is reflected at the second surface of the prism; At least some of the IR light reflected from the second surface of the prism is reflected at the first surface of the prism; At least some of the IR light reflected from the first surface of the prism is reflected at the third surface of the prism; as well as At least some of the IR light reflected from the third surface of the prism is reflected at the fourth surface of the prism so that it passes through the third surface and exits the prism.

15. The device of claim 13, wherein the light folding element further comprises a portion of a surface of the light folding element facing the environment, and wherein the portion is configured to have refractive power.

16. The device of claim 15, wherein the light folding element further comprises a coating on the surface of the light folding element facing the environment, and wherein the coating is configured to increase at least one of the transmission or reflection of the IR light at the surface of the light folding element.

17. The device of claim 13, further comprising at least one wafer-level lens, the at least one wafer-level lens comprising one or more plastic portions of a glass substrate attached to the at least one wafer-level lens.

18. The device of claim 17, wherein the optical folding element further comprises a coating on the surface of the optical folding element facing the at least one wafer-level lens, and wherein the coating is configured to increase at least one of the transmission or reflection of the IR light at the surface of the optical folding element.

19. The device of claim 13, wherein the camera is positioned facing the environment to which the IR light is projected.

20. An apparatus, the apparatus comprising: A camera, which faces the environment in front of the device and is configured to capture images of objects in the environment based on visible light received through a camera aperture; Projector, the projector comprising: Infrared (IR) light emitter, the IR light emitter is configured to emit IR light; and An optical folding element configured to receive the IR light and reflect the IR light once or multiple times to guide the IR light through the optical folding element and a projector aperture to project the IR light onto the environment; and A detector configured to detect or identify the object in the environment using IR light from the projector, reflected by the object, and received through a detector aperture. The IR light emitter is displaced relative to the camera and the detector in a second direction perpendicular to a first direction in which the camera and the detector are arranged, so as to at least partially overlap with the detector in the second direction, wherein the first direction and the second direction form a plane perpendicular to the optical axis of the camera, and wherein the camera aperture, the projector aperture and the detector aperture are aligned in the first direction.

Images