Optical systems and wearable devices

Abstract

The present application discloses an optical system and a wearable device, wherein the optical system includes: a light source; a collimating unit; a first waveguide, wherein a first light guiding portion is provided in the first waveguide, the first waveguide has a target exit surface, and the light guiding surface of the first light guiding portion faces the light exit surface of the light source; a reflecting unit, wherein the reflecting unit has a reflecting surface, and the reflecting surface faces the target exit surface; a second waveguide, wherein the second waveguide is arranged on a first side of the first waveguide; an optical path adjusting unit, wherein the optical path adjusting unit is arranged at an end of the second waveguide away from the collimating unit, and the optical path adjusting unit guides the light emitted from the reflecting surface into the second waveguide; wherein the light emitted by the light source is collimated by the collimating unit, transmitted to the first waveguide, and is reflected by the light guiding surface and then emitted from the target exit surface, the reflecting surface reflects the light emitted from the target exit surface to the optical path adjusting unit, the optical path adjusting unit guides the light reflected by the reflecting surface into the second waveguide, and the second light guiding portion guides the light introduced by the optical path adjusting unit out of the second waveguide.

Description

Technical Field

[0001] The present application belongs to the field of optical technology of augmented reality glasses, and specifically relates to an optical system and a wearable device having the optical system. Background Art

[0002] In the field of AR technology, the light emitted by the light source is introduced from one end of the waveguide through a collimating lens and output from the other end of the waveguide, finally entering the human eye to present an image.

[0003] However, in the currently available related technologies, the projection module composed of the screen and the collimating lens is relatively large in size, and the image quality (color, stripes) of the folded light path is relatively poor. Summary of the Invention

[0004] The present application aims to provide an optical system and a wearable device that at least solve one of the problems of the background technology.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application proposes an optical system, comprising: a light source; a collimating unit, the collimating unit being arranged on a transmission path of light emitted by the light source; a first waveguide, a first light guiding portion being arranged therein, the first waveguide having a target exit surface, the light guiding surface of the first light guiding portion being oriented toward the light exit surface of the light source; a reflecting unit, the reflecting unit having a reflecting surface, the reflecting surface being oriented toward the target exit surface; a second waveguide, the second waveguide being arranged on a first side of the first waveguide, the second light guiding portion being arranged therein; and an optical path adjusting unit. The entire unit is arranged at one end of the second waveguide away from the collimating unit, and the optical path adjustment unit guides the light emitted from the reflecting surface into the second waveguide; wherein, the light emitted by the light source is collimated by the collimating unit, transmitted to the first waveguide, and is reflected by the light guiding surface and then emitted from the target exit surface, the reflecting surface reflects the light emitted from the target exit surface to the optical path adjustment unit, the optical path adjustment unit guides the light reflected by the reflecting surface into the second waveguide, and the second light guiding part guides the light introduced by the optical path adjustment unit out of the second waveguide.

[0007] In a second aspect, an embodiment of the present application proposes a wearable device comprising the optical system described in any of the above embodiments.

[0008] In an embodiment of the present application, by arranging the second waveguide on the first side of the first waveguide and arranging the optical path adjustment unit at the end of the second waveguide away from the collimation unit, light can be introduced from the first waveguide, then reflected by the reflection unit, and finally introduced into the second waveguide through the optical path adjustment unit. This can not only improve the image quality, but also improve the propagation efficiency of light and reduce the loss of light.

[0009] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0011] Figure 1 is a schematic diagram of an optical system according to one embodiment of the present application;

[0012] Figure 2 is a schematic diagram of an optical system according to yet another embodiment of the present application;

[0013] Figure 3 is a schematic diagram of an optical system according to yet another embodiment of the present application;

[0014] Figure 4 is a schematic diagram of an optical system according to yet another embodiment of the present application;

[0015] Figure 5 is a schematic diagram of an optical system according to another embodiment of the present application.

[0016] Reference numerals:

[0017] Optical system 100;

[0018] Light source 10;

[0019] collimation unit 20;

[0020] First waveguide 30; first light guide portion 31;

[0021] Reflection unit 40; Reflection surface 41;

[0022] Second waveguide 50; Second light guide 51;

[0023] Optical path adjustment unit 60; semi-transparent and semi-reflective film 61; reflective polarizer 62;

[0024] First glass slide 63; second glass slide 64; third glass slide 65; fourth glass slide 66;

[0025] Human eye 200. DETAILED DESCRIPTION

[0026] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and are not to be construed as limiting the present invention. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of this application.

[0027] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly refer to one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more. Furthermore, the term "and / or" in the specification and claims refers to at least one of the connected entities, and the character " / " generally indicates an "or" relationship between the connected entities.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0029] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0030] The following combination Figures 1 to 5 An optical system 100 according to an embodiment of the present invention is described.

[0031] like Figures 1 to 5 As shown, an optical system 100 according to some embodiments of the present invention includes: a light source 10 , a collimating unit 20 , a first waveguide 30 , a reflecting unit 40 , a second waveguide 50 and an optical path adjusting unit 60 .

[0032] Specifically, the collimating unit 20 is arranged on the transmission path of the light emitted by the light source 10, the first waveguide 30 is provided with a first light guiding portion 31, the first waveguide 30 has a target exit surface, the light guiding surface of the first light guiding portion 31 faces the light exit surface of the light source 10, the reflecting unit 40 has a reflecting surface 41, and the reflecting surface faces the target exit surface. The second waveguide 50 is arranged on a first side of the first waveguide 30, and the second light guiding portion 51 is provided in the second waveguide 50. The optical path adjustment unit 60 is provided at an end of the second waveguide 50 away from the collimating unit 20, and the optical path adjustment unit 60 guides the light emitted from the reflecting surface 41 into the second waveguide 50. Among them, the light emitted by the light source 10 is collimated by the collimating unit 20, transmitted to the first waveguide 30, and emitted from the target output surface after being reflected by the light guiding surface. The reflecting surface 41 reflects the light emitted from the target output surface to the optical path adjustment unit 60. The optical path adjustment unit 60 introduces the light reflected by the reflecting surface 41 into the second waveguide 50, and the second light guiding part 51 guides the light introduced by the optical path adjustment unit 60 out of the second waveguide 50.

[0033] In other words, the optical system 100 according to an embodiment of the present application is primarily composed of a light source 10 capable of emitting imaging light, a collimating unit 20 for collimating the light emitted by the light source 10, a first waveguide 30 for transmitting the collimated light, a reflecting unit 40 for reflecting the light from the first waveguide 30, an optical path adjustment unit 60 for directing the reflected light into the second waveguide 50, and a second waveguide 50 for directing the light out. The light source 10 can be a projection device capable of projection, and the light emitted by the light source 10 is the light actually emitted by the projection device. If the light source 10 is not polarized light, a polarizer can be added as needed.

[0034] It should be noted that the collimating unit 20 is provided on the transmission path of the light emitted by the light source 10 and can collimate and adjust the light of the light source 10. The light collimated by the collimating unit 20 can enter the first waveguide 30 from the end of the first waveguide 30 close to the collimating unit 20.

[0035] Furthermore, a first light guiding portion 31 is provided within the first waveguide 30, and the first light guiding portion 31 can be located at an end of the first waveguide 30 that is close to the collimating unit 20. Furthermore, the first light guiding portion 31 has a light guiding surface that can be arranged opposite to the light exit surface of the light source 10. After light from the light source 10 is collimated by the collimating unit 20, the light can enter the first waveguide 30 from an end of the first waveguide 30 that is close to the collimating unit 20 and reach the light guiding surface of the first light guiding portion 31. Subsequently, the light continues to propagate within the first waveguide 30 after being reflected or refracted by the light guiding surface. Furthermore, the first waveguide 30 also has a target exit surface that can be located at an end of the first waveguide 30 that is away from the collimating unit 20, wherein the light propagating within the first waveguide 30 can be emitted from the first waveguide 30 through the target exit surface.

[0036] It should also be noted that the reflection unit 40 can be provided at one end of the first waveguide 30 away from the collimation unit 20 , and the reflection unit 40 has a reflection surface 41 , which can reflect the light emitted from the target exit surface to the optical path adjustment unit 60 .

[0037] Furthermore, the optical path adjustment unit 60 can be provided at an end of the second waveguide 50 away from the collimating unit 20 , and can guide the light reflected by the reflecting surface 41 into the second waveguide 50 .

[0038] In addition, a second light guide portion 51 is provided in the second waveguide 50 . The second light guide portion 51 can guide the light introduced by the optical path adjustment unit 60 out of the second waveguide 50 , thereby allowing the light to enter the human eye 200 .

[0039] For ease of description, Figure 1 As shown, the extension direction of the first waveguide 30 can be defined as extending left and right, and the assembly direction of the light source 10, the collimating unit 20 and the first waveguide 30 can be defined as assembling along the up and down direction.

[0040] That is to say, the left end of the first waveguide 30 can be the end close to the collimating unit 20, and the right end of the first waveguide 30 can be the end away from the collimating unit 20. The first light guide portion 31 can be arranged inside the first waveguide 30 and at a position close to the left side (the first light guide portion 31 here is a light introduction portion, which can be a geometric introduction or a grating introduction, which is not limited here), and the target exit surface can be arranged at the right end face of the first waveguide 30. The light guiding surface of the first light guiding portion 31 can be arranged opposite to the light exit surface of the light source 10. For example, the first light guiding portion 31 can be located directly below the light source 10 and the area of ​​the light guiding surface of the first light guiding portion 31 can be larger than the area of ​​the light exit surface.

[0041] Furthermore, the light emitted by the light source 10 can be adjusted by the collimating unit 20 and then enter the interior of the first waveguide 30 from the left end of the first waveguide 30, so that the light can be transmitted to the light guiding surface of the first light guiding portion 31. Due to refraction or reflection on the light guiding surface, the light can continue to be transmitted inside the first waveguide 30 along the extension direction of the first waveguide 30 until it reaches the target exit surface of the first waveguide 30.

[0042] In addition, the second waveguide 50 may be disposed above the first waveguide 30, and the left end of the second waveguide 50 may be disposed adjacent to the left end of the first waveguide 30. For example, the extension direction of the first waveguide 30 and the extension direction of the second waveguide 50 may be parallel to each other.

[0043] It should be noted that the optical path adjustment unit 60 can be provided at the right end of the second waveguide 50. For example, when the reflection unit 40 is provided at the right end of the first waveguide 30, the optical path adjustment unit 60 can be located above the reflection unit 40. In addition, the human eye 200 can be located above the second waveguide 50 and can be opposite to the second light guide portion 51.

[0044] The light source 10 is positioned above the collimating unit 20. After the light emitted by the light source 10 passes through the collimating unit 20, it can be transmitted from the left end of the first waveguide 30 to the right end of the first waveguide 30. Then, when the light reaches the right end of the first waveguide 30, it can be emitted from the target exit surface of the first waveguide 30. Next, the light emitted from the target exit surface can reach the reflecting unit 40. The reflecting surface 41 of the reflecting unit 40 can reflect the light emitted from the target exit surface to the optical path adjustment unit 60. Finally, the optical path adjustment unit 60 can guide the light reflected by the reflecting surface 41 to the right end of the second waveguide 50. After the light enters the second waveguide 50, the second light guiding portion 51 in the second waveguide 50 guides the light guided by the light path adjustment unit 60 out of the second waveguide 50 and reaches the human eye 200. The human eye 200 can then observe the light guided by the second light guiding portion 51.

[0045] Therefore, according to the optical system 100 of the embodiment of the present application, by arranging the second waveguide 50 on the first side of the first waveguide 30 and arranging the optical path adjustment unit 60 at the end of the second waveguide 50 away from the collimation unit 20, light can be introduced from the first waveguide 30, then reflected by the reflection unit 40, and finally introduced into the second waveguide 50 through the optical path adjustment unit 60. This not only improves the image quality, but also, under the condition that the light emitted by the light source 10 is polarized light, improves the propagation efficiency of the light and reduces the loss of light.

[0046] According to one embodiment of the present application, Figures 1 to 4 As shown, the reflective unit 40 is disposed at the end of the first waveguide 30 away from the collimating unit 20. The optical axis of the optical system 100 is perpendicular to a tangent plane of the reflective unit 40, which is the tangent plane at the point of contact between the light and the reflective unit when the light is transmitted to the reflective unit. In other words, when the end of the first waveguide 30 away from the collimating unit is the right end, the reflective unit 40 can be located at the right end of the first waveguide 30, and the reflective unit 40 can be disposed opposite the target emission surface of the first waveguide 30.

[0047] Furthermore, the optical axis of the optical system 100 can be perpendicular to the tangent plane of the reflective unit. It should be noted that the tangent plane here refers to the plane passing through the point of contact between the light and the reflective unit. When the optical axis of the optical system 100 is perpendicular to the tangent plane of the reflective unit, the optical system can be coaxial, thereby producing better image quality and preventing image blur.

[0048] By arranging the reflective unit 40 at the end of the first waveguide 30 away from the collimating unit, the light reflected by the reflective surface 41 can better reach the optical path adjustment unit 60, thereby facilitating the adjustment of the light by the optical path adjustment unit 60. In addition, by arranging the optical axis of the optical system 100 perpendicular to the tangent plane of the reflective unit 40, the light emitted from the target exit surface can better fall onto the reflective surface 41, ensuring that the reflective surface 41 can reflect the light into the optical path adjustment unit 60, thereby further reducing light loss.

[0049] According to some optional embodiments of the present application, such as Figure 1 As shown, the optical path adjustment unit 60 is a semi-transparent and semi-reflective film 61 , which is disposed between an end of the first waveguide 30 away from the collimating unit 20 and an end of the second waveguide 50 away from the collimating unit 20 .

[0050] That is, the optical path adjustment unit 60 may be a semi-transparent and semi-reflective film 61. When the end of the first waveguide 30 away from the collimating unit 20 is the right end, the end of the second waveguide 50 away from the collimating unit 20 is also the right end, and the semi-transparent and semi-reflective film 61 may be located between the right end of the first waveguide 30 and the right end of the second waveguide 50.

[0051] At this time, the propagation path of the light can be as follows: the light emitted by the light source 10 is collimated by the collimating unit 20 and reaches the left end of the first waveguide 30. After being reflected or refracted by the first light guide portion 31, the light continues to propagate toward the right end of the first waveguide 30. When the light reaches the right end of the first waveguide 30, the light emitted through the target exit surface can reach the reflecting unit 40. The light reflected by the reflecting surface 41 can pass through the semi-transparent semi-reflective film 61, wherein a portion of the light passes through the semi-transparent semi-reflective film 61 and enters the second waveguide 50. The remaining light is reflected by the semi-transparent semi-reflective film 61 and reaches the reflecting unit 40. Then, after being reflected by the reflecting surface 41, it is projected through the semi-transparent semi-reflective film 61 to reach the second waveguide 50, and then passes through the second light guide portion 51 to be emitted to the human eye 200.

[0052] It should be noted that when the above transmission method is adopted, the optical system 100 can be placed in a coaxial condition, which can effectively avoid unclear image quality or even image distortion.

[0053] That is, each time light is transmitted to the portion provided with the semi-transparent and semi-reflective film 61, part of the light can be transmitted into the second waveguide 50, and the other part of the light can be reflected by the semi-transparent and semi-reflective film 61 and then enter the reflecting unit 40. After being reflected by the reflecting surface 41, the light can reach the second waveguide 50. In the actual use of the product, the following can be adopted: Figure 1The path of the light in the middle (ie, the path of first reflection and then transmission) achieves a relatively ideal optical efficiency, where the optical efficiency is reflectivity*transmittance, for example, the optical efficiency is 50%*50%=25%.

[0054] Optionally, the light emitted by the light source 10 is linearly polarized light, such as the light emitted by an LCD (Liquid Crystal Display). When the light emitted by the light source is linearly polarized light, the propagation efficiency of the light can be improved.

[0055] Optionally, a polarizer is provided between the light source 10 and the light-guiding surface. That is, when the light emitted by the light source 10 is natural light, a polarizer can be provided between the light-guiding surface and the light source 10 so that the light emitted by the light source 10 is converted into polarized light after passing through the polarizer and enters the first waveguide 30, thereby improving the propagation efficiency of the light.

[0056] According to one embodiment of the present application, Figure 2 As shown, the optical path adjustment unit 60 includes a reflective polarizer 62 and a first glass plate 63. The reflective polarizer 62 is disposed between an end of the first waveguide 30 away from the collimating unit 20 and an end of the second waveguide 50 away from the collimating unit 20, and the first glass plate 63 is disposed between the target exit surface and the reflecting unit 40. It should be noted that the optical system 100 in this embodiment can also achieve relatively ideal effects under the condition of being coaxial, and the specific reasons are not repeated here.

[0057] Specifically, when the optical path adjustment unit 60 comprises a reflective polarizer 62 and a first glass plate 63, the reflective polarizer 62 may be located between an end of the first waveguide 30 away from the collimating unit 20 and an end of the second waveguide 50 away from the collimating unit 20. For example, when the end of the first waveguide 30 away from the collimating unit is the right end, and the end of the second waveguide 50 away from the collimating unit 20 is also the right end, the reflective polarizer 62 may be located between the first waveguide 30 and the second waveguide 50, and the reflective polarizer 62 may be located above both the first waveguide 30 and the reflecting unit 40. Optionally, the reflective polarizer 62 may have a strip-shaped cross-section.

[0058] In addition, the first glass slide 63 can be arranged between the target exit surface and the reflection unit 40. For example, the first glass slide 63 can be a quarter glass slide. In this case, the light emitted by the light source 10 can be linearly polarized light or natural light. When the light emitted by the light source is natural light, a polarizer needs to be added between the light source 10 and the light-guiding surface. It should be noted that the glass slide is an optical device that can produce an additional optical path difference (or phase difference) between two mutually perpendicular light vibrations. The glass slide is usually made of a birefringent wafer such as quartz, calcite or mica with a precise thickness, and its optical axis is parallel to the wafer surface. When linearly polarized light is incident vertically on the wafer, its vibration direction forms an angle θ with the optical axis of the wafer (θ≠0°), and the incident light vibration can be decomposed into two components perpendicular to the optical axis (o vibration) and parallel to the optical axis (e vibration).

[0059] It should be noted that the glass slide that can produce an additional optical path difference of λ / 4 between o-light and e-light is called a quarter glass slide; the glass slide that can produce an additional optical path difference of λ / 2 between o-light and e-light is called a half glass slide. The glass slide whose optical path difference can be arbitrarily adjusted is called a compensator. Among them, linearly polarized light remains linearly polarized light after passing through the 1 / 2 glass slide (but the phase has changed). When linearly polarized light passes through the 1 / 4 glass slide (when the vibration direction of the linearly polarized light is at a 45-degree angle to the crystal axis), circularly polarized light is emitted, and generally elliptically polarized light is emitted. Circularly polarized light becomes linearly polarized light after passing through the 1 / 4 glass slide, and extinction will occur when observed with a polarizing filter. Natural light passing through the 1 / 4 glass slide will form an infinite number of various elliptically polarized light rays with no fixed phase relationship. After their combination, they are still natural light, and the light intensity does not change when observed with a polarizing filter.

[0060] That is, when the first glass slide 63 is a quarter-glass slide, the light propagation path can be as follows: the light emitted by the light source 10 is collimated by the collimating unit 20 and reaches the left end of the first waveguide 30. The light is reflected or refracted by the first light guide 31 and continues to propagate toward the right end of the first waveguide 30. When the light reaches the right end of the first waveguide 30, the light emitted through the target exit surface can pass through the first glass slide 63.

[0061] Since linearly polarized light will become circularly polarized light after passing through the quarter glass, the light emitted from the target exit surface will become circularly polarized light after passing through the first glass 63. After the circularly polarized light reaches the reflection unit 40, it will be reflected by the reflection surface 41 and will pass through the first glass 63 again to become linearly polarized light. The linearly polarized light can then reach the reflective polarizer 62.

[0062] Since the reflective polarizer 62 can filter light, the linearly polarized light reflected by the reflective surface 41 and then passed through the first glass 63 can reach the second waveguide 50 through the reflective polarizer 62. Then, the light can be guided out of the second waveguide 50 through the second light guide portion 51 and directed toward the human eye 200, thereby forming a better image quality.

[0063] According to some optional embodiments of the present application, such as Figure 3 As shown, the optical path adjustment unit 60 includes a reflective polarizer 62, a second glass plate 64, and a third glass plate 65. The reflective polarizer 62 is disposed between the end of the first waveguide 30 away from the collimator 20 and the end of the second waveguide 50 away from the collimator 20. The second glass plate 64 is disposed between the end of the first waveguide 30 closer to the collimator 20 and the collimator 20. After being collimated by the collimator 20, the light passes through the second glass plate 64 and enters the first waveguide 30. Because the third glass plate 65 is disposed between the end of the first waveguide 30 away from the collimator 20 and the reflective polarizer 62, the light guided from the first light guide 31 passes through the third glass plate 65 and is transmitted to the reflective polarizer 62. After being reflected by the reflective polarizer 62, the light passes through the third glass plate 65 and is transmitted to the reflective surface 41. Then, after being reflected by the reflective surface 41, the light passes through the third glass plate 65 again and then through the reflective polarizer 62 to enter the second waveguide 50.

[0064] The optical path adjustment unit 60 may also include a reflective polarizer 62, a second glass plate 64, and a third glass plate 65. When the end of the first waveguide 30 away from the collimating unit 20 is the right end, and the end of the second waveguide 50 away from the collimating unit 20 is also the right end, the reflective polarizer 62 may be positioned between the right end of the first waveguide 30 and the right end of the second waveguide 50, and the third glass plate 65 may be positioned between the right end of the first waveguide 30 and the reflective polarizer 62. In other words, the reflective polarizer 62 and the third glass plate 65 may be positioned between the first waveguide 30 and the second waveguide 50, and the reflective polarizer 62 may be positioned above the third glass plate 65. Furthermore, the second glass plate 64 may be positioned at the left end of the first waveguide 30 and between the first waveguide 30 and the collimating unit 20.

[0065] It should be noted that, in this embodiment, the optical system 100 can also achieve a relatively ideal effect under the condition of being coaxial, and the specific reasons are not repeated here.

[0066] Optionally, the second glass slide 64 and the third glass slide 65 can both be quarter glass slides. In this case, the light emitted by the light source 10 can still be linearly polarized light or natural light. When the light emitted by the light source is natural light, a polarizing plate needs to be added between the light source 10 and the second glass slide 64.

[0067] Specifically, when the second glass slide 64 and the third glass slide 65 can both be quarter glass slides, the propagation path of the light can be as follows: the light emitted by the light source 10 can pass through the second glass slide 64 to enter the left end of the first waveguide 30 after being collimated by the collimating unit 20. At this time, the light changes from linearly polarized light to circularly polarized light, and then the circularly polarized light can continue to be transmitted to the right end of the first waveguide 30 after reflection or refraction by the first light guide part 31 until it reaches the target exit surface.

[0068] like Figure 3 As shown, for the sake of convenience of description, the point where the light falls on the reflecting surface 41 can be defined as point D. If the light before reaching point D is the first circularly polarized light, the first circularly polarized light will become the first linearly polarized light when it passes through the third glass slide 65 for the first time. At this time, when the reflection axis direction of the reflective polarizer 62 is appropriate, it can reflect the first linearly polarized light; the reflected first linearly polarized light can pass through the third glass slide 65 for the second time, at which time the first linearly polarized light becomes the second circularly polarized light and can reach point D; then the second circularly polarized light can pass through the third glass slide 65 for the third time after being reflected by the reflecting surface 41, at which time the second circularly polarized light becomes the second linearly polarized light, and the polarization direction of the second linear polarized light is rotated 90 degrees with respect to the first linear polarized light, so that the second linearly polarized light can just pass through the reflective polarizer 62 and enter the second waveguide 50.

[0069] Optionally, the reflective polarizer 62 and the third glass 65 between the first waveguide 30 and the second waveguide 50 can be of appropriate lengths to increase the amount of light that can pass through the reflective polarizer 62 and the third glass 65 .

[0070] That is to say, by providing the reflective polarizer 62, the second glass 64 and the third glass 65, the light propagation efficiency can be improved, and the waste of light can be avoided, thereby ensuring the clarity of image color and lines.

[0071] According to one embodiment of the present application, Figure 4 As shown, the light emitted by the light source 10 is circularly polarized light, and the light path adjustment unit 60 includes: a reflective polarizer 62 and a fourth glass plate 66 .

[0072] Specifically, the reflective polarizer 62 is arranged between the end of the first waveguide 30 away from the collimating unit and the end of the second waveguide 50 away from the collimating unit, and the fourth glass plate 66 is arranged between the end of the first waveguide 30 away from the collimating unit 20 and the reflective polarizer 62. The light guided by the first light guide portion 31 is transmitted through the fourth glass plate 66 to the reflective polarizer 62, and after being reflected by the reflective polarizer 62, it is transmitted through the fourth glass plate 66 to the reflective surface 41. After being reflected by the reflective surface 41, it passes through the fourth glass plate 66 again and passes through the reflective polarizer 62 to enter the second waveguide 50.

[0073] That is to say, when the light emitted by the light source 10 is directly circularly polarized light, there is no need to set a quarter glass between the end of the first waveguide 30 close to the collimating unit 20 and the collimating unit 20, thereby omitting the step of converting linearly polarized light into circularly polarized light, thereby greatly improving the propagation efficiency of light.

[0074] According to one embodiment of the present application, Figures 1 to 4 As shown, the target emission surface is offset relative to the end surface of the second waveguide 50 distal from the collimating unit 20 in the direction of the end of the first waveguide 30 proximal to the collimating unit 20. The reflective unit 40 is disposed between the target emission surface and the end surface of the second waveguide 50 distal from the collimating unit 20. That is, when the end of the first waveguide 30 proximal to the collimating unit 20 is considered the left end, and the end of the first waveguide 30 distal from the collimating unit 20 is considered the right end, the end of the second waveguide 50 distal from the collimating unit 20 is also considered the right end. In this case, with the right end surface of the second waveguide 50 as a reference, the right end of the first waveguide 30 can be located to the left of the right end surface of the second waveguide 50. In other words, the right end of the second waveguide 50 extends further to the right than the right end of the first waveguide 30, extending a distance beyond the right end of the first waveguide 30.

[0075] At this time, the reflection unit 40 can be located below the right end of the second waveguide 50, and the left side of the reflection unit 40 can be arranged opposite to the target emission surface. At this time, the optical path adjustment unit 60 can largely reflect the light reflected by the reflection unit 40.

[0076] By staggering the target exit surface and the end surface of the second waveguide 50 away from the collimating unit 20, and arranging the reflecting unit 40 between the target exit surface and the end surface of the second waveguide 50 away from the collimating unit 20, not only the overall structure is made more compact, but also it is beneficial to the transmission of light, so that more light is introduced into the second waveguide 50 through the optical path adjustment unit 60.

[0077] According to some optional embodiments of the present application, such as Figure 5 As shown, the optical path adjustment unit 60 is a cylindrical reflector, and the reflecting surface 41 of the optical path adjustment unit 60 is opposite to the end face of the second waveguide 50 away from the collimating unit 20, and the reflecting surface 41 of the optical path adjustment unit 60 is arranged opposite to the reflecting surface 41 of the reflecting unit 40. The optical axis of the optical system 100 and the tangent plane of the reflecting unit 40 have a preset angle, and the preset angle is 0° to 90°. The tangent plane is the tangent plane of the contact point between the light and the reflecting unit 40 when the light is transmitted to the reflecting unit 40.

[0078] It should be noted that according to the transmission method of this embodiment, the optical system 100 can be placed under off-axis conditions to achieve a more ideal effect. Therefore, the optical axis of the optical system 100 and the cross-section of the reflective unit 40 can be set to a preset angle. The preset angle is 0°~90°, excluding the right endpoint value. It should be noted that the cross-section here also refers to the surface passing through the contact point between the light and the reflective unit when the light is irradiated on the reflective unit.

[0079] That is, when the optical path adjustment unit 60 is a cylindrical reflector, the optical path adjustment unit 60 can be set at the end of the second waveguide 50 away from the collimation unit 20, and the reflection surface of the optical path adjustment unit 60 can be set opposite to the reflection surface 41 of the reflection unit 40.

[0080] At this time, when the end face of the second waveguide 50 away from the collimating unit 20 is the right end face, the transmission path of the light can be as follows: First, the light source 10 can be located above the collimating unit 20. After the light emitted by the light source 10 is collimated by the collimating unit 20, the light can be transmitted from the left end of the first waveguide 30 to the right end of the first waveguide 30. When the light reaches the right end of the first waveguide 30, it can be emitted from the target exit surface. Then, the light emitted from the target exit surface can reach the reflecting unit 40. The reflecting surface 41 of the reflecting unit 40 can reflect the light emitted from the target exit surface to the optical path adjustment unit 60. Next, the light reaches the reflecting surface of the optical path adjustment unit 60. The light emitted from the reflecting surface 41 is reflected by the reflecting surface of the optical path adjustment unit 60 and can be transmitted to the second waveguide 50. After reaching the second waveguide 50, the light can be guided out of the second waveguide 50 through the second light guide portion 51, thereby reaching the human eye 200.

[0081] By setting the optical path adjustment unit 60 as a cylindrical reflector arranged opposite to the reflection unit 40, the complementary characteristics of the optical path adjustment unit 60 and the reflection unit 40 can be utilized to guide light from the reflection unit 40 into the second waveguide 50, thereby compensating for the disadvantages of image display caused by off-axis.

[0082] According to one embodiment of the present application, Figure 5 As shown, the target exit surface is flush with the end surface of the second waveguide 50 away from the collimating unit 20, and the optical path adjustment unit 60 is symmetrically arranged with the reflecting unit 40. That is, when the optical path adjustment unit 60 is a cylindrical reflector arranged opposite to the reflecting unit 40, in order to enable more comprehensive adjustment of the light reflected from the reflecting surface 41, the target exit surface is flush with the end surface of the second waveguide 50 away from the collimating unit 20, and the optical path adjustment unit 60 is symmetrically arranged with the reflecting unit 40, so that the light reflected by the reflecting surface 41 can be more reflected onto the reflecting surface of the optical path adjustment unit 60.

[0083] When the end of the second waveguide 50 away from the collimating unit 20 is the right end, the right end of the first waveguide 30 may be in the same horizontal plane as the right end of the second waveguide 50 , and the right end of the second waveguide 50 may be located directly above the right end of the first waveguide 30 .

[0084] When both the optical path adjustment unit 60 and the reflective unit 40 are cylindrical reflectors, the size of the optical path adjustment unit 60 can be the same as that of the reflective unit 40, and this is not limited here. The shape of the optical path adjustment unit 60 can also be the same as that of the reflective unit 40, and this is not limited here. For example, when the size and shape of the optical path adjustment unit 60 and the reflective unit 40 are exactly the same, the optical path adjustment unit 60 and the reflective unit 40 can be symmetrically arranged, and the reflective surface of the optical path adjustment unit 60 can be opposite to the reflective surface 41 of the reflective unit 40.

[0085] According to some optional embodiments of the present application, a light-proof layer is provided on the outer surface of each of the first waveguide 30 and the second waveguide 50 in the thickness direction. To better absorb stray light emitted from the first waveguide 30 and the second waveguide 50, a light-proof layer can be provided on the outer surface of the first waveguide 30 and the second waveguide 50 in the thickness direction. For example, the edges of the first waveguide 30 and the second waveguide 50 can be painted black. The specific material of the light-proof layer is not limited herein.

[0086] In summary, according to the optical system 100 of the embodiment of the present application, by setting the first waveguide 30 as the introduction waveguide, the second waveguide 50 as the extraction waveguide, the second waveguide 50 being disposed on a first side of the first waveguide 30, and the optical path adjustment unit 60 being disposed at the end of the second waveguide 50 away from the collimation unit 20, light can be guided out of the first waveguide 30 by first passing through the reflection unit 40 and then through the optical path adjustment unit 60, and finally guided into the second waveguide 50, and then emitted into the human eye 200 from the second waveguide 50. According to the optical system 100 of this embodiment, not only can the image quality of optical imaging be further optimized, but also the efficiency of light can be improved, thereby avoiding the loss of a large amount of energy during the return process of light.

[0087] According to the wearable device according to the embodiment of the present application, it includes the optical system 100 according to the above embodiment. Since the optical system 100 according to the above embodiment of the present application has the above technical effects, the wearable device according to the embodiment of the present application also has the corresponding technical effects, that is, the overall structure is more compact, and the colors and lines of the image quality are clearer, thereby improving the viewing experience of the human eye 200.

[0088] Among them, the wearable device can be AR glasses, the waveguide 30 can be the lens of the AR glasses, the light source 10 can be a projection device arranged on one of the temples of the AR glasses, and the reflection unit 40 can be arranged in the middle of the glasses near the bridge of the nose. The light emitted by the light source 10 is transmitted from one end of the lens close to the light source 10 to the other end of the lens close to the bridge of the nose. After being reflected by the reflection unit 40, the light returns to the lens and is exported from the light export position on the lens to the human eye 200, and the human eye 200 can then see the virtual image emitted by the light source 10.

[0089] Other components of the wearable device according to the embodiment of the present invention, such as the assembly structure of the projection device and the waveguide, and the operation thereof, are well known to those skilled in the art and will not be described in detail here.

[0090] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0091] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. An optical system, characterized in that: include: light source; a collimating unit, the collimating unit being provided on a transmission path of the light emitted by the light source; a first waveguide, wherein a first light guiding portion is provided in the first waveguide, the first waveguide has a target emission surface, and the light guiding surface of the first light guiding portion faces the light emission surface of the light source; a reflecting unit, the reflecting unit having a reflecting surface, the reflecting surface facing the target exit surface; a second waveguide, the second waveguide being disposed on a first side of the first waveguide, and having a second light guiding portion disposed therein; an optical path adjustment unit, the optical path adjustment unit being provided at an end of the second waveguide away from the collimating unit, the optical path adjustment unit guiding the light emitted from the reflecting surface into the second waveguide; The light emitted by the light source is collimated by the collimating unit, transmitted to the first waveguide, and emitted from the target exit surface after being reflected by the light guiding surface. The reflecting surface reflects the light emitted from the target exit surface to the optical path adjustment unit. The optical path adjustment unit guides the light reflected by the reflecting surface into the second waveguide. The second light guiding part guides the light guided by the optical path adjustment unit out of the second waveguide. A polarizer is provided between the light source and the light guiding surface; The optical path adjustment unit is a semi-transparent and semi-reflective film, and the semi-transparent and semi-reflective film is provided between an end of the first waveguide away from the collimating unit and an end of the second waveguide away from the collimating unit.

2. The optical system according to claim 1, wherein: The reflecting unit is arranged at one end of the first waveguide away from the collimating unit, and the optical axis of the optical system is perpendicular to the tangent plane of the reflecting unit. The tangent plane is the tangent plane of the contact point between the light and the reflecting unit when the light is transmitted to the reflecting unit.

3. The optical system according to claim 1, wherein: The target exit surface is offset relative to the end surface of the second waveguide away from the collimating unit in the direction of the end of the first waveguide close to the collimating unit, and the reflecting unit is arranged between the target exit surface and the end surface of the second waveguide away from the collimating unit.

4. The optical system according to claim 1, wherein: The first waveguide and the second waveguide are provided with a light-proof layer on their outer surfaces in the thickness direction.

5. A wearable device, characterized in that: The optical system comprises the optical system according to any one of claims 1 to 4.

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