CN113433609A

CN113433609A - Optical system and wearable device

Info

Publication number: CN113433609A
Application number: CN202110563460.5A
Authority: CN
Inventors: 汤伟平
Original assignee: Vivo Mobile Communication Co Ltd
Current assignee: Vivo Mobile Communication Co Ltd
Priority date: 2021-05-21
Filing date: 2021-05-21
Publication date: 2021-09-24
Anticipated expiration: 2041-05-21
Also published as: CN113433609B

Abstract

The application discloses optical system and wearable equipment, optical system includes: a light source; the collimation unit is arranged on a light transmission path of the light source; the waveguide is provided with a first light guide part, a second light guide part and a target emergent surface, and the light guide surface of the first light guide part faces the emergent surface of the light source; and the reflecting surface of the reflecting unit forms an included angle with the target emergent surface, the included angle is smaller than 90 degrees, the optical axis of the optical system and the tangent plane of the reflecting unit form a preset angle, and the tangent plane is the tangent plane of a contact point of the light and the reflecting unit when the light is transmitted to the reflecting unit. The light emitted by the light source is collimated by the collimating unit, transmitted into the waveguide from the first end of the waveguide and reflected by the light guide surface and then emitted from the target emergent surface, the light emitted from the target emergent surface is reflected to the second light guide part by the reflecting surface, and the light reflected by the reflecting unit is guided out of the waveguide by the second light guide part.

Description

Optical system and wearable device

Technical Field

The application belongs to the technical field of augmented reality glasses optics, and particularly relates to an optical system and wearable equipment with the same.

Background

However, after the light emitted by the light source is transmitted through the waveguide, the light is optically off-axis relative to the reflector, which causes that the image quality of the final imaging is difficult to optimize, has larger astigmatism, and simultaneously has asymmetric distortion and is difficult to correct.

Disclosure of Invention

The application aims to provide an optical system and a wearable device, and at least one of the problems of light ray off-axis and unclear image quality is solved.

In order to solve the technical problem, the present application is implemented as follows:

in a first aspect, an embodiment of the present application provides an optical system, including: a light source; the collimation unit is arranged on a light transmission path of the light source; the light guide device comprises a waveguide, a first light guide part, a second light guide part and a target emergent surface, wherein the light guide surface of the first light guide part faces the emergent surface of the light source; the reflecting unit, form the contained angle between the reflecting surface of reflecting unit and the target exit surface, the contained angle is less than 90 °, optical axis of optical system and tangent plane of reflecting unit have the angle of predetermineeing, the tangent plane is the tangent plane of the contact point of light and reflecting unit when light transmits to the reflecting unit, wherein, after the light that the light source sent passes through collimation unit collimation, from the first end of waveguide to in the waveguide, and after the reflection of leaded light face, from the target exit surface jets out, the reflecting surface reflects the light that jets out from the target exit surface to the second leaded light portion, the second leaded light portion exports the light that the reflecting unit reflected out the waveguide.

In a second aspect, an embodiment of the present application provides a wearable device including the optical system in the foregoing embodiment.

In the embodiment of the application, the degree of an included angle between the reflecting surface and the target emergent surface is set to be smaller than 90 degrees, and the optical axis of the optical system and the tangent plane of the reflecting unit form a preset angle, so that the light rays which are emitted out of the waveguide after passing through the first light guide part, the second light guide part and the reflecting unit cannot be off-axis or the off-axis range is controllable, the off-axis problem when the light rays emitted by the light source reach eyes is avoided, the image quality of optical imaging is better optimized, and distortion symmetry is effectively corrected.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic diagram of an optical system in the prior art

FIG. 2 is a schematic diagram of an optical system according to an embodiment of the present application;

FIG. 3 is a schematic diagram of simulated light rays of an optical system according to an embodiment of the present application;

fig. 4 is an enlarged view of a portion P circled in fig. 3.

Reference numerals:

an optical system 100;

a light source 10;

a collimating unit 20;

a waveguide 30; first light guide portions 31; second light directing portions 32; a target exit surface 33;

a reflection unit 40;

a light absorbing means 50;

a cylindrical mirror 60;

a screen 1; and a collimator lens 2.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The features of the terms first and second in the description and in the claims of the present application may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specified. In addition, "and/or" in the specification and claims means at least one of connected objects, a character "/" generally means that a preceding and succeeding related objects are in an "or" relationship.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The present application is an invention created by the inventors based on the following facts.

At present, for projection equipment, the image quality of an image can be improved by additionally arranging a cylindrical mirror and a cylindrical reflector, but because the angles of light rays entering a guide surface are different, the angles of the light rays reflected by the guide surface are also different, so that the off-axis phenomenon can occur, and the astigmatism is larger. As shown in fig. 1, the screen 1 is located right above the collimator lens 2, and the center of the screen 1 passes through the optical axis of the collimator lens, and the left-end light source a and the right-end light source b of the screen 1 are the same in distance from the center point M on the screen. However, after a series of radiation refractions, the distances from the a ' point and the b ' point to the central point M ' are changed when reaching the eye, namely, the problem of off-axis occurs. Therefore, the image quality seen by eyes is not clear, the whole picture is deformed, and the experience effect is finally influenced.

Based on this, the inventors of the present application have conducted long-term research and experiments to inventively derive the optical system 100 and the wearable device of the present application.

An optical system 100 according to an embodiment of the present invention is described below with reference to fig. 2 to 4.

As shown in fig. 2-4, an optical system 100 according to some embodiments of the present invention includes: a light source 10, a collimating unit 20, a waveguide 30 and a reflecting unit 40.

Specifically, the collimating unit 20 is disposed on a light transmission path of the light source 10, the waveguide 30 is disposed with a first light guiding portion 31, a second light guiding portion 32 and a target emitting surface 33, the light guiding surface of the first light guiding portion 31 faces the light emitting surface of the light source 10, and an included angle is formed between the reflecting surface of the reflecting unit 40 and the target emitting surface 33, and the included angle is smaller than 90 °. The optical axis of the optical system and the section of the reflection unit have a preset angle, and the section is a section of a contact point of the light and the reflection unit when the light is transmitted to the reflection unit. The light emitted from the light source 10 is collimated by the collimating unit 20, transmitted into the waveguide 30 from the first end of the waveguide 30, reflected by the light guide surface, and emitted from the target exit surface 33, the light emitted from the target exit surface 33 is reflected by the reflection surface to the second light guide part 32, and the light reflected by the reflection unit 40 is guided out of the waveguide 30 by the second light guide part 32.

Optionally, the reflecting surface of the reflecting unit 40 may be a plane or an arc surface, and when the reflecting surface of the reflecting unit 40 is a plane, an included angle between the reflecting surface and the target exit surface 33 may be an included angle between a normal vector of the reflecting surface and a normal vector of the target exit surface 33; in the case that the reflecting surface is a curved surface, an included angle between the reflecting surface and the target exit surface 33 may be an included angle between a central axis of the reflecting surface and a normal vector of the target exit surface 33.

In other words, the optical system 100 according to the embodiment of the present application is mainly composed of the light source 10 that can emit imaging light, the collimating unit 20 that collimates the light emitted from the light source 10, the waveguide 30 that transmits the collimated light, and the reflecting unit 40 that reflects the light guided out from the waveguide 30 and reflects the light back to the waveguide 30. The light source 10 may be a projection device capable of performing projection, and the light emitted by the light source 10 is light actually emitted by the projection device.

For convenience of description, the extending direction of the waveguide 30 is defined as extending left and right, and the assembling direction of the light source 10, the collimating unit 20, and the waveguide 30 is defined as being assembled in the up-down direction.

The first light guide part 31 is disposed at a position closer to the left side inside the waveguide 30 (the first light guide part 31 here is a light guide part, and may be a geometric guide or a grating guide, and is not limited thereto), the light guide surface of the first light guide part 31 may be disposed opposite to the light exit surface of the light source 10, for example, the first light guide part 31 may be located right below the light source 10, and the area of the light guide surface of the first light guide part 31 may be larger than the area of the light exit surface.

Further, the light emitted from the light source 10 may enter the inside of the waveguide 30 from the left end of the waveguide 30 after being adjusted by the collimating unit 20, so that the light may be transmitted to the light guiding surface of the first light guiding part 31. The light rays can continue to be transmitted inside the waveguide 30 along the extending direction of the waveguide 30 by refraction or reflection of the light guide surface, etc., until the light rays can reach the target exit surface 33 of the waveguide 30.

In addition, the right side surface of the waveguide 30 is further provided with a reflection unit 40, light can reach the reflection unit 40 through the target exit surface 33, an included angle can be formed between the target exit surface 33 of the waveguide 30 and the reflection surface of the reflection unit 40, and the degree of the included angle is smaller than 90 °. That is, the reflecting surface can be disposed obliquely with respect to the target exit surface. Further, a predetermined angle can be formed between the optical axis of the optical system 100 and the tangent plane of the reflection unit 40. It should be noted that the light beam forms a light spot, i.e. a contact point, on the reflecting surface when the light beam is transmitted to the reflecting unit 40. And the tangent plane of the reflecting unit 40 can pass through the contact point and be perpendicular to the light forming the contact point. At this time, the optical axis can have a predetermined angle with the tangent plane.

After the light reaches the reflection unit 40 through the target exit surface 33, the reflection surface of the reflection unit 40 can reflect the light back into the waveguide 30. A second light guide portion 32 is further disposed inside the waveguide 30 at a position close to the right side (the second light guide portion 32 here is a light guide portion, and may be guided by a geometric reflection array or a grating, which is not limited herein). The light reflected by the reflecting surface of the reflecting unit 40 can reach the second light guiding portion 32, the second light guiding portion 32 can reflect or refract the light out of the waveguide 30, and the light is emitted from the waveguide 30 to reach human eyes, so that the human eyes can watch the light guided out by the second light guiding portion 32.

It should be noted that the optical system 100 itself has an optical axis, and when the light is transmitted to the waveguide 30 under the condition that the light coincides with the optical axis, the light emitted from the target exit surface 33 has a predetermined angle with the tangential plane. It should be noted here that the reflecting unit 40 may be disposed obliquely with respect to the target exit surface 33 of the waveguide 30 such that the optical axis remains perpendicular or approximately perpendicular to the tangent plane of the reflecting unit 40.

That is, the light rays of the light source 10 are emitted from the same point to form a light cone, wherein the light rays overlapping with the optical axis can be first collimated by the collimating unit 20, then incident into the waveguide 30, then reflected or refracted by the first light guide unit 31, then transmitted through the waveguide 30, and then emitted from the target emission surface 33 by changing the transmission angle repeatedly for a plurality of times, and then can reach the reflection surface of the reflecting unit 40.

It should be noted that, when the degree of the included angle that can be formed after the light coincident with the optical axis is emitted to the reflecting surface can fall within the range of the preset angle, most of the rest of the light that does not pass through the optical axis is reflected back to the waveguide 30 from the reflecting surface, and the off-axis phenomenon is not generated. Therefore, the problem of off-axis when the light emitted by the light source 10 reaches the eyes can be avoided, the image quality of optical imaging is better optimized, and the distortion symmetry is effectively corrected.

Therefore, according to the optical system 100 of the embodiment of the present application, the degree of the included angle between the reflecting surface and the target emergent surface is set to be smaller than 90 °, and the optical axis of the optical system and the tangent plane of the reflecting unit form a preset angle, so that the light rays exiting the waveguide 30 after passing through the first light guiding part 31, the second light guiding part 32 and the reflecting unit 40 do not have off-axis or have controllable off-axis range, and the off-axis problem when the light rays emitted by the light source 10 reach the eyes is avoided, thereby the image quality of the optical imaging is better optimized, and the distortion symmetry is effectively corrected.

According to an embodiment of the present application, as shown in fig. 4, the optical system 100 further includes: and the light absorption device 50 is arranged on the side surface of the second end of the waveguide 30, the side surface of the second end is adjacent to the target emergent surface, the light absorption surface of the light absorption device faces the reflecting surface, the light absorption device 50 is used for absorbing residual light emitted from the reflecting surface, and the included angle formed by the residual light and the reflecting surface exceeds a preset angle.

For example, the ray a and the ray B emitted from the point C in fig. 2 are taken as an example for explanation.

The light ray a and the optical axis may be considered to coincide, the light ray B is a light ray far away from the optical axis, the light ray a and the light ray B emitted by the light source 10 may be collimated by the collimating unit 20 and then transmitted into the waveguide 30, and after the light ray a and the light ray B are guided into the first light guiding portion 31, the two light rays are transmitted in parallel and totally reflected in the waveguide 30. When the light ray A and the light ray B reach the reflecting unit 40, light spots can be formed on the reflecting surface, wherein the light spot formed by projecting the light ray A on the reflecting surface is a point D, and the light spot formed by projecting the light ray B on the reflecting surface is a point E, but because the total reflection times of the light ray A and the light ray B are different, the degree of an included angle formed by the light ray A and the light ray B with the reflecting surface is different, and the included angle formed by the light ray B and the reflecting surface does not fall into the range of a preset angle, so that the light ray A and the light ray B are not parallel after being reflected by the reflecting unit 40. The B ray can be understood as residual light, that is, the included angle formed by the residual light and the reflecting surface exceeds a preset angle and cannot return to the waveguide.

However, in the actual simulation, it is found that the B ray has a small ratio in the total ray, and reflects off the waveguide 30 in the vicinity of the reflecting unit 40 without being introduced into the human eye. Although most of the light is reflected back into the waveguide 30, the proportion of B rays is not much and is guided out of the waveguide 30, and the remaining light can be absorbed by using the light absorbing properties of the light absorbing means 50.

That is, the light absorbing device 50 may be disposed at a side of the second end of the waveguide 30 to absorb the residual light, so as to avoid light interference and influence on the normal use of the optical system 100. Note that the side of the second end of the waveguide 30 is adjacent to the target exit surface, and the light absorbing surface of the light absorbing device 50 can be disposed toward the reflecting surface. As shown in fig. 4, the dotted line can be understood as the original direction of the residual light ray, and therefore, the exit surface of the residual light from the waveguide 30 can be understood as the side surface of the second end of the waveguide 30. And the light absorbing surface of the light absorbing means 50 can be understood as the surface opposite to the exit surface of the surplus light from the waveguide 30.

Alternatively, the light absorbing means 50 comprises, but is not limited to, a rough black housing.

According to some alternative embodiments of the present application, as shown in FIG. 4, the light absorbing surface of light absorbing means 50 is spaced apart from the side of the second end of waveguide 30 to form a gap. When the light absorbing means 50 absorbs the residual light emitted from the waveguide 30, if the light absorbing means 50 is attached to the side of the second end of the waveguide 30, the residual light is reflected back to the waveguide 30 by the light absorbing means 50.

In other words, the light absorbing surface is not completely attached to the side surface of the second end of the waveguide 30, but the light absorbing surface of the light absorbing device 50 is spaced from the side surface of the second end of the waveguide 30 to form a gap, so that the residual light can be absorbed more completely, the residual light is prevented from leaking and interfering with human eyes, and the residual light can be prevented from being reflected back to the waveguide 30, which causes image distortion finally.

According to one embodiment of the present application, as shown in FIG. 4, the light-absorbing surface is disposed parallel to a side surface of the second end of the waveguide 30. Since the excessive light cannot be emitted perpendicularly to the first side surface of the waveguide 30 when it is emitted from the waveguide 30, if the angle between the light absorbing surface and the side surface of the second end of the waveguide 30 is the same as the angle between the excessive light and the side surface of the second end of the waveguide 30, that is, if the light absorbing surface is parallel to the side surface of the second end of the waveguide 30, even if the excessive light is parallel to the emitted excessive light, the excessive light cannot be absorbed by the light absorbing surface. For example, the light absorbing means 50 may be located above the waveguide 30 and near the reflecting unit 40. The light absorbing surface is opposite to the position of the residual light.

That is, by arranging the light absorbing surface in parallel with the side surface of the second end of the waveguide 30, not only can the light absorbing surface be fully utilized, but also it can be avoided that the light absorbing surface is inclined with respect to the waveguide 30 so that the excessive light cannot be irradiated onto the light absorbing surface.

According to some alternative embodiments of the present application, light absorbing means 50 is an opaque sheet. Through setting up extinction device 50 into lamellar body structure, not only occupation space is little, is convenient for produce moreover and process. In addition, by providing the light absorption device 50 with a non-light-transmissive material, the residual light can be absorbed more sufficiently, and the residual light can be prevented from being transmitted.

According to one embodiment of the present application, the waveguide 30 extends in a first direction, the reflection unit 40 is a cylindrical mirror, and an axial extending direction of the cylindrical mirror is disposed obliquely with respect to the first direction.

For convenience of description, the first direction may be defined as a left-right direction.

That is, as shown in fig. 2, the waveguide 30 can extend in the left-right direction. Further, when the reflection unit 40 is a cylindrical mirror, the cylindrical mirror has an axis, wherein the axis may be a straight line parallel to the reflection surface, and an extending direction of the axis may be disposed obliquely with respect to an extending direction of the waveguide. The axis extending direction of the cylindrical reflector is inclined relative to the first direction, so that an included angle can be formed between the reflecting surface of the reflecting unit 40 and the target emergent surface 33, and the included angle can be ensured to be smaller than 90 degrees, so that off-axis or controllable off-axis range can not occur to light rays which are emitted out of the waveguide 30 after passing through the first light guide part 31, the second light guide part 32 and the reflecting unit 40, and the off-axis problem when the light rays emitted by the light source 10 reach eyes is avoided.

In addition, the cylindrical reflector adopts a smooth and continuous surface type, so that the original direction return of light can be realized while the light path adjustment is realized, and the imaging effect is further ensured. For example, the reflection surface of the reflection unit 40 may be a concave surface, and a tangent plane of the concave surface can pass through a point where the light is projected on the reflection unit 40.

Alternatively, the reflection unit 40 is integrally formed with the waveguide 30. For example, one end of the waveguide 30 may be provided as an arc-shaped surface, and a reflective film may be coated on the end surface of the waveguide 30, so that when light is transmitted along the direction in which the waveguide 30 extends, the light can reach the end surface of the waveguide 30, be reflected, and be reflected back to the second light guide part 32.

According to some alternative embodiments of the present application, the preset angle ranges from 75 ° to 90 °. Note that the preset angle includes an end point value. That is, when the light emitted from the optical axis reaches the reflective surface, and the included angle between the light incident on the reflective surface and the reflective surface is 75 ° to 90 °, the light emitted from the light source 10 does not have the off-axis phenomenon or the off-axis phenomenon within a controllable range, and the optical system 100 can be ensured to present a clear and good image quality.

According to one embodiment of the present application, the light rays are emitted from the reflecting surface to be perpendicular to the reflecting surface. For example, the extending direction of the optical axis is defined as a vertical direction, and light rays passing through the optical axis or hypothetical light rays are reflected by the first light guide unit 31, then emitted perpendicularly to the reflection surface in a direction parallel to the waveguide 30, and then emitted from the reflection surface to the second light guide unit 32, and light rays emitted from the waveguide 30 by the second light guide unit 3232 or hypothetical light rays also extend in the vertical direction. That is, by limiting the light emitted from the target exit surface 33 to enter the reflection surface in a vertical state, the light emitted from the light source 10 can be effectively prevented from being off-axis, thereby ensuring the imaging effect of the optical system 100.

According to some alternative embodiments of the present application, as shown in fig. 2, the optical system 100 further comprises: the cylindrical mirror 60 is disposed between the collimating unit 20 and the first light guiding portion 31, and the light emitted by the light source 10 is collimated by the collimating unit 20 and then transmitted to the waveguide 30 through the cylindrical mirror 60.

In other words, the cylindrical mirror 60 is located between the collimating unit 20 and the waveguide 30, and the cylindrical mirror 60 is located opposite to the light guiding surface of the first light guiding part 31. The light emitted from the light source 10 can be collimated and adjusted by the collimating unit 20 and then incident into the cylindrical mirror 60, and the light passing through the cylindrical mirror 60 can be diffused or gathered. The cylindrical mirror 60 is usually a smooth and continuous surface, which not only can adjust the optical path, but also can reduce the scattering and loss of light. By adopting the cylindrical mirror 60 combination, the original angle of the light in the plane of the screen is returned, and the size of the projection optical machine is reduced. Moreover, the reflection part has no abrupt edge angle, so that the reflection part is relatively smooth, and the image can be prevented from generating texture.

In summary, according to the optical system 100 of the embodiment of the present application, the reflection unit 40 is obliquely disposed, and an included angle between a light passing through the optical axis and the reflection surface is within a range of a preset angle, and the first light guide portion 31 and the second light guide portion 32 are simultaneously matched with each other, so that the light exiting from the waveguide 30 after passing through the first light guide portion 31, the second light guide portion 32 and the reflection unit 40 is not off-axis or the off-axis range is controllable, and the off-axis problem when the light emitted from the light source 10 reaches the eyes is avoided, so that the image quality of the optical imaging is better optimized, and the distortion symmetry is effectively corrected.

According to the wearable device of the embodiment of the application, the wearable device comprises the optical system 100 according to the embodiment, and the optical system 100 according to the embodiment of the application has the technical effects, so that the wearable device according to the embodiment of the application also has the corresponding technical effects, namely, the light of the light source 10 does not have off-axis when reaching the eyes, the image quality of optical imaging is better optimized, the distortion symmetry is effectively corrected, and the viewing experience effect of human eyes is improved.

Wherein, wearable equipment can be AR glasses, waveguide 30 can be the lens of AR glasses, light source 10 can be the projection equipment on locating one mirror leg of AR glasses, reflection unit 40 then can locate the position that the glasses middle part is close to the bridge of the nose, the light that light source 10 sent is close to the one end of this light source 10 from a lens, transmit to the other end that this lens is close to the bridge of the nose, after reflection unit 40 reflects, light returns the lens, and derive people's eye from the light derivation position on the lens, people's eye can watch the virtual image that light source 10 sent.

Other constructions of wearable devices according to embodiments of the invention, such as the mounting structure of the projection device and the waveguide, and the operation thereof, are known to those of ordinary skill in the art and will not be described in detail herein.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An optical system, comprising:

a light source;

the collimation unit is arranged on a light transmission path of the light source;

the light guide device comprises a waveguide, a first light guide part, a second light guide part and a target emergent surface, wherein the light guide surface of the first light guide part faces the emergent surface of the light source;

a reflecting unit, an included angle is formed between the reflecting surface of the reflecting unit and the target emergent surface, the included angle is smaller than 90 degrees,

the optical axis of the optical system and the section of the reflecting unit have a preset angle, and the section is a section of a contact point of the light and the reflecting unit when the light is transmitted to the reflecting unit;

the light emitted by the light source is collimated by the collimating unit, transmitted into the waveguide from the first end of the waveguide, reflected by the light guide surface and emitted from the target emergent surface, the light emitted from the target emergent surface is reflected to the second light guide part by the reflecting surface, and the light reflected by the reflecting unit is guided out of the waveguide by the second light guide part.

2. The optical system of claim 1, further comprising:

the light absorption device is arranged on the side surface of the second end of the waveguide, the side surface of the second end is adjacent to the target emergent surface, the light absorption surface of the light absorption device faces the reflecting surface, and the light absorption device is used for absorbing residual light emitted from the reflecting surface;

and the included angle formed by the residual light and the reflecting surface exceeds the preset angle.

3. The optical system of claim 2, wherein the light-absorbing surface is spaced apart from a side surface of the second end of the waveguide forming a gap.

4. The optical system of claim 3, wherein the light-absorbing surface is disposed parallel to a side surface of the second end of the waveguide.

5. The optical system of claim 2, wherein the light absorbing means is an opaque sheet.

6. An optical system according to claim 1, characterized in that the waveguide extends in a first direction, the reflecting unit is a cylindrical mirror, and the direction of axial extension of the cylindrical mirror is arranged obliquely with respect to the first direction.

7. The optical system of claim 1, wherein the predetermined angle is in a range of 75 ° to 90 °.

8. The optical system of claim 7, wherein the light ray exits the reflective surface perpendicular to the reflective surface.

9. The optical system of claim 1, further comprising:

the cylindrical mirror is arranged between the collimation unit and the first light guide part, and light rays emitted by the light source are collimated by the collimation unit and then transmitted to the waveguide through the cylindrical mirror.

10. A wearable device comprising the optical system of any of claims 1-9.