Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of 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 invention.
Fig. 1 is a schematic structural diagram of a VR device according to an embodiment of the present invention, and as shown in fig. 1, the lens includes:
an outer barrel 11, an inner barrel 12, and a lens 14 attached to the inner barrel 12 and/or the outer barrel 11, which are relatively rotatable; one of the inner barrel 12 and the outer barrel 11 is mounted with a first polarizing film 13; the other is mounted with a second polarizing film 15; when the inner barrel 12 and the outer barrel 11 rotate relatively, the polarization directions of the first polarization film 13 and the second polarization film 15 are the same or different.
Where the lens 14 refers to a lens capable of performing a lens function, for example, in a VR device, the lens 14 refers to a lens (a single lens or a lens group) capable of being a magnified virtual image, including but not limited to a spherical lens, an aspherical lens, or a fresnel lens.
Optionally, in this embodiment, the lens 14 may be a single lens mounted in the inner barrel 12 or the outer barrel 11, or may be a lens group mounted in the inner barrel 12 and/or the outer barrel 11.
In an alternative embodiment, when the lens 14 is a single lens, the first polarizing film 13 may be disposed on the lens 14, and the second polarizing film 15 may be disposed on a flat mirror to form a polarizer; alternatively, the first polarizing film 13 may be provided on a flat mirror to form a polarizer, and the second polarizing film 15 may be provided on the lens 14. In fig. 1, the technical solution provided by the embodiment of the present invention is illustrated by an example in which the second polarizing film 15 is provided on the lens 14, and it should be understood that the technical solution of the present invention includes, but is not limited to, the illustration.
When the lens 14 is provided with the second polarizing film 15, light having the same polarization direction as the second polarizing film 15 may pass through the lens 14. By controlling the angle between the polarization directions of the first polarizing film 13 and the second polarizing film 15, it is possible to control whether the light passing through the lens 14 enters human eyes. In practice, the second polarizing film 15 may be attached to the optical surface of the lens 14 in the direction close to the human eye, or the second polarizing film 15 may be plated on the optical surface of the lens 14 in the direction close to the human eye, which is not limited in this embodiment.
In another alternative embodiment, when the lens 14 is a lens group, the first polarizing film 13 and the second polarizing film 15 can be respectively disposed on two different single lenses in the lens group. In this embodiment, no new lens needs to be introduced into the VR device, which is beneficial to make the VR device more lightweight.
In fig. 1, a case where the lens 14 provided with the second polarizing film 15 is mounted in the outer barrel 11 and the first polarizing film 13 is mounted in the inner barrel 12 is illustrated; in practice, it may be: the lens 14 provided with the second polarizing film 15 is installed in the inner barrel 12, and the first polarizing film 13 is installed in the outer barrel 11, which is not limited in this embodiment.
Based on the working principle that the polarizing films can transmit light with the same polarization direction, when the VR device is in a use state (object light can enter human eyes through the lens 14), the polarization directions of the first polarizing film 13 and the second polarizing film 15 can be kept the same; when the VR device is in the non-use state, the polarization directions of the first polarizing film 13 and the second polarizing film 15 may be kept different. Preferably, when the polarization directions of the first polarizing film 13 and the second polarizing film 15 are maintained to be orthogonal, the shielding effect against the external environment light is optimized. Based on the structure provided by the present embodiment, the arrangement of the polarization directions of the first and second polarization films 13 and 15 can be realized by the relative rotation between the inner barrel 12 and the outer barrel 11.
When the inner lens barrel 12 and the outer lens barrel 11 rotate relatively, a force can be applied to the outer lens barrel 11 to enable the outer lens barrel 11 to rotate around the outer wall of the inner lens barrel 12; force can also be applied to the inner barrel 12 to rotate the inner barrel 12 around the inner wall of the outer barrel 11, which is not limited in this embodiment.
In such a structure, the outer barrel 11 and the inner barrel 12 can be relatively rotated, and the polarization directions of the second polarization film 15 and the first polarization film 13 provided on the lens 14 can be changed by rotating the inner barrel or the outer barrel. When the VR device is not in use, the polarization directions of the first polarizing film 13 and the second polarizing film 15 can be kept different, which can weaken the intensity of the external light passing through the lens, and is beneficial to protecting the device of the lens object space. When the VR device is in a use state, the polarization directions of the first polarizing film 13 and the second polarizing film 15 can be kept the same, so that the object light can smoothly pass through the lens.
Alternatively, the inner barrel 12 and the outer barrel 11 may have the same diameter with the end faces facing each other. In such an embodiment, the end surfaces of the inner barrel 12 and the outer barrel 11 may be provided with annular guide rails to ensure relative rotation between the inner barrel 12 and the outer barrel 11. Alternatively, the inner barrel 12 and the outer barrel 11 may be fixed to two different support members of the VR device, respectively, and by rotating the two different support members, the inner barrel 12 and the outer barrel 11 may be relatively rotatable.
The embodiment in which the end surfaces of the inner barrel 12 and the outer barrel 11 are opposite to each other makes the VR device have a large longitudinal size, which is not favorable for miniaturization of the VR device. In a preferred embodiment, the inner barrel 12 may have a smaller diameter than the outer barrel 11, and one end of the inner barrel 12 may be located inside the outer barrel 11. Such an embodiment is advantageous for reducing the longitudinal dimension of the VR device. The following sections will be described with reference to specific examples.
In an alternative embodiment, the outer barrel 11 and the inner barrel 12 can be mechanically rotated relative to each other by a guide rail and a slider.
In the embodiment of mechanical relative rotation, the cylinder 110 of the outer barrel 11 may be provided with a guide rail 111 extending along a non-axial direction; a first sliding part 121 matched with the guide rail 111 is fixedly arranged on the outer wall of the inner lens barrel 12; the first sliding member 121 is disposed in the guide rail 111 and slidably connected to the guide rail 111.
The barrel 110 of the outer barrel 11 refers to a part other than the two end surfaces of the outer barrel 11, that is, a side surface of the outer barrel 11. The non-axial direction means that the extending direction of the guide rail 111 does not coincide with the direction of the rotation center axis of the cylinder 110. The guide rail 110 is designed in a non-axial direction, so that the inner lens barrel 12 and the outer lens barrel 11 can rotate around the central axis as a rotation center, and finally the purpose of changing the included angle between the polarization directions of the first polarization film 13 and the second polarization film 15 is achieved.
The first sliding member 121 may be a column or a block, and the shape thereof may be adapted to the shape of the guide rail 111, which is not limited herein. The first sliding part 121 penetrates the guide rail, and when the inner barrel 12 or the outer barrel 11 is subjected to an external force, the first sliding part 121 and the guide rail 111 slide relatively to each other, so as to drive the inner barrel 12 and the outer barrel 11 to rotate relatively.
When the cylinder 110 of the outer barrel 11 is provided with the guide rail 111 extending along the non-axial direction, an alternative embodiment may be as shown in fig. 2: the guide rail 111 is provided in the non-cylindrical direction of the cylindrical body 110.
The circumferential direction of the cylinder refers to a direction perpendicular to the axial direction and the radial direction of the cylinder 110, that is, the guide rail 111 may be formed along a slant line, an arc line, or a spiral track on the cylinder 110. Such a slant line, an arc line or a spiral track can enable the first sliding member 121 and the guide rail 111 to slide relatively when the inner barrel 12 or the outer barrel 11 is subjected to either a rotational force or a pushing force. Besides the rotation movement, since the guide rail 111 extends along the non-cylinder circumference direction, when the first sliding member 121 and the guide rail 111 slide relatively, the inner barrel 12 and the outer barrel 11 can be driven to move telescopically.
Alternatively, in the present embodiment, in order to prevent the first polarizing film 13 or the lens 14 mounted in the outer barrel 11 from being damaged by the telescopic movement between the inner barrel 12 and the outer barrel 11, the positions of the guide rail 111 and the first slider 121 may be designed so as to satisfy the following conditions: when the first slider 121 slides from the start end to the end of the guide rail 111, the end of the inner barrel 12 located inside the outer barrel 11 does not contact the first polarizing film 13 or the lens 14 mounted inside the outer barrel 11.
Alternatively, when the VR device is not in use, the included angle between the polarization directions of the first polarizing film 13 and the second polarizing film 15 may be set to any one of 45 °, 60 °, 90 °, or 0 to 90 ° (not including 0 °), so that the polarization directions of the first polarizing film 13 and the second polarizing film 15 are kept different. Preferably, when the polarization directions of the first polarizing film 13 and the second polarizing film 15 are 90 ° (orthogonal), the shielding capability of the VR device to external light is strongest.
Based on this, in order to ensure that the angle between the polarization directions of the first polarizing film 13 and the second polarizing film 15 can be changed between 0 ° and 90 °, the projection length of the guide rail 111 in the cylinder circumferential direction of the cylinder 110 can be designed to be a quarter of the cylinder circumferential length. Here, the circumferential length refers to a path length obtained by winding a complete turn in the circumferential direction of the cylindrical body 110. In practice, in order to facilitate the inner barrel 12 to rotate well inside the outer barrel 11, the outer barrel 11 and the inner barrel 12 may be designed as cylindrical barrels. In this case, the cylinder circumferential direction is the circumferential direction of the cylinder, and the cylinder circumferential length is the circumferential length corresponding to the cross section of the cylinder. When the projection length of the guide rail 111 in the cylinder circumferential direction of the cylinder body 110 is a quarter of the cylinder circumferential length, and the first slider 121 rotates from the starting end to the end of the guide rail 111 or from the end to the starting end of the guide rail 111, the inner barrel 12 rotates by exactly a quarter of a circumferential angle (360 °) relative to the outer barrel 11, and the included angle between the polarization directions of the first polarization film 13 and the second polarization film 15 changes by 90 °.
Alternatively, when the first slider 121 is positioned at one end of the guide rail 111 close to the human eye side, the first polarizing film 13 may be disposed to be orthogonal to the polarization direction of the second polarizing film 15. Further, when the VR device is not in use, the first slider 121 may be slid to an end of the guide rail 111 near the human eye side; when the VR device is in a use state, a user may apply a rotational force or a pushing force to the inner barrel 12, so that the first slider 121 slides to an end of the guide rail 111 close to the object. When the first sliding member 121 is located at one end of the guide rail 111 close to the object, the polarization directions of the first polarizing film 13 and the second polarizing film 15 are the same, and light can pass through the lens 14.
In practice, if the inner barrel 12 is close to the user and the outer barrel 11 is close to the object, the user can attach eyes to the end of the inner barrel 12 not inside the outer barrel 11 and apply pressure to the inner barrel 12 along the axial direction when using the VR device. If the outer barrel 11 is close to the user side and the inner barrel 12 is close to the object, the user can stick the eyes to one end of the outer barrel 11 far away from the inner barrel 12 and apply pressure to the outer barrel 11 along the axial direction when using the VR device. Under this kind of scene, along with user's use action, for example wear the action or place VR equipment in the action of eye, can realize that VR equipment from shading state noninductive switching to printing opacity state, greatly promoted user experience.
Alternatively, on the basis of the structure described in the foregoing embodiment, the present invention further provides a VR device as shown in fig. 3. As shown in fig. 3, in addition to the structure described in the foregoing embodiment, a positioning member 112 may be disposed on the cylinder 110 at a position close to one end of the guide rail 111 near the human eye, and the positioning member 112 and the first slider 121 are connected by an elastic element 16. The elastic element 16 may be a rubber band or a spring, and the embodiment is not limited.
Wherein, the end of the guide rail 111 near the human eye side can be the starting end of the guide rail 111, and the positioning member 112 is used for defining the position of the first sliding member 121 through the elastic element 16. When the VR device is not in use, the first slide 121 is located at the beginning of the guide rail 111, and the elastic element 16 is in a contracted state. When the VR device is in use, a rotational force or a pushing force may be applied to the inner barrel 12 or the outer barrel 11, so that the first slider 121 slides to the end (end near the object) of the guide rail 111, at which time the elastic member 16 is stretched.
Based on the structure shown in fig. 3, when using the VR device, a user can attach the eye to one lens barrel of the VR device close to the human eye, and apply an axial thrust to the lens barrel close to the human eye. With the user's action, the first slider 121 slides from the starting end to the end of the guide rail 111, and the VR device is switched from the light-shielding state to the light-transmitting state without feeling. After the use, the user can keep away from the eye of the user and the VR device is close to the lens barrel of the eye of the user, so as to release the axial thrust applied to the lens barrel close to the eye of the user, and at this time, the elastic element 16 automatically contracts to drive the first sliding part 121 to return to the starting end of the guide rail 111. Under this condition, along with user's end use action, VR equipment has switched to the shading state from the printing opacity state noninductive, does not need user's extra operation, and is very convenient, has greatly promoted user experience.
It should be understood that in the above embodiments, the starting end or the end of the guide rail 111 is with respect to the direction or the object side of the human eye. In some cases, the outer barrel 11 is applied close to the object side, and in other cases, the outer barrel 11 is applied close to the user side. In the above two different application modes, the starting end and the end of the guide rail 111 correspond to different positions, which is not described herein again.
Alternatively, the following section will describe the VR device provided in the present embodiment by taking the example in which the outer barrel 11 is used near the object and the inner barrel 12 is used near the user.
Alternatively, on the basis of the structure described in the foregoing embodiment, the present invention further provides a VR device as shown in fig. 4. When the outer barrel 11 is applied close to the object and the inner barrel 12 is applied close to the user, as shown in fig. 4, the VR device includes a ball bearing 17 and a second slider 18 shown in fig. 4 in addition to the structure described in the foregoing embodiment. Wherein, the ball bearing 17 is arranged on the end surface of the inner lens cone 12 close to the human eye side, and the second sliding part 18 is fixedly arranged on the ball bearing 17. When the second sliding member 18 transmits pressure to the ball bearing 17, the inner barrel 12 is driven to slide along the guide rail 111.
In use of the VR device, a user may apply an axial thrust to the ball bearing 17 via the second slide 18 by placing the eye against the second slide 18. With the user's action, the first slider 121 slides from the starting end to the end of the guide rail 111, and the VR device is switched from the light-shielding state to the light-transmitting state without feeling. After use, the user can move his or her eyes away from the second sliding member 18 to release the axial thrust applied to the ball bearing 17, and at this time, the elastic member 16 automatically contracts to drive the first sliding member 121 to return to the starting end of the guide rail 111. Under this condition, along with user's end use action, VR equipment has switched to the shading state from the printing opacity state automatically, does not need user's extra operation, and is very convenient, has greatly promoted user experience.
The above embodiments corresponding to fig. 2 to 4 describe alternative embodiments in which when the cylindrical body 110 of the outer barrel 11 is provided with the guide rail 111 extending in the non-axial direction, the guide rail 111 may be provided in the non-circumferential direction of the cylindrical body 110. In addition to the above embodiments, as shown in fig. 5: the guide rail 111 may be provided in the circumferential direction of the cylindrical body 11. The length of the guide rail 111 is a quarter of the length of the bobbin circumference, and when the first slider 121 rotates from the start end to the end of the guide rail 111, the first slider rotates by exactly a quarter of the circumference angle (360 °), that is, 90 °, so that the included angle between the polarization directions of the first polarizing film 13 and the second polarizing film 15 is adjusted within 0-90 °.
In this embodiment, a user may apply a rotational force on the inner barrel 12 or the outer barrel 11 so that the first slider 121 slides around the cylinder circumferential direction of the cylinder body 110 to achieve relative rotation of the inner barrel 12 and the outer barrel 11.
In practice, in order to facilitate the inner barrel 12 to rotate well inside the outer barrel 11, the outer barrel 11 and the inner barrel 12 may be designed as cylindrical barrels. At this time, the circumferential direction of the cylinder is the circumferential direction of the cylinder, and the circumferential length of the cylinder is the circumferential length corresponding to the cross section of the cylinder, which is not described in detail.
Optionally, in the embodiments corresponding to fig. 1 to 5, in addition to the structures shown in the figures, the VR device provided by the present invention further includes a device front shell 61 and a device rear shell 62 buckled with the device front shell 61, as shown in fig. 6 a. Wherein the device front case 61 contains the lens frame 19. The lens frame 19 is provided with a through hole 191, and the outer barrel 11 is mounted in the through hole 191. The lens frame 19 is used to fix the lens barrel, so that the lens is convenient to use with the display device.
In some embodiments, as shown in fig. 6b, when the outer barrel 11 and the inner barrel 12 are slidably connected through the first sliding member 121, the guide rail 111, the positioning member 112 and the elastic element 16 shown in fig. 3 or fig. 4, the top end of the positioning member 112 may contact with the inner wall of the through hole 191, and then the elastic element 16 is clamped between the inner wall of the through hole 191 and the outer wall of the outer barrel 11, so as to avoid the elastic element 16 from falling off when being impacted by an external force or bumpy, and enhance the stability of the function of the VR device.
Optionally, as shown in fig. 6a, the VR device provided in this embodiment further includes a left head band 63 and a right head band 64. The left head strap 63 and the right head strap 64 can be respectively arranged on two sides of the rear shell 61 of the device, and can also be arranged on two sides of the front shell 61 of the device; in fig. 6a, the left head band 63 and the right head band 64 are shown on both sides of the rear case 62 of the device, but the invention is not limited thereto.
Wherein, the left head strap 63 and the right head strap 64 can be elastic structures, rubber bands or elastic bands; or a rigid structure with a clutch or telescopic structure, such as a plastic strap provided with a strap tightness adjusting mechanism, etc. The user can wear the VR device on the head through the left head band 63 and the right head band 64, and can adjust the wearing comfort by adjusting the left head band 63 and the right head band 64.
When the user wears the VR equipment, the front shell 61 of the equipment is tightly attached to the face of the user, and the user can watch the virtual image displayed on the display screen through the lens. In an alternative embodiment, when the VR device is in the configuration shown in fig. 2-4, the device front shell 61 fits against the user's face such that the user's eye is in direct or indirect contact with the inner barrel 12 around the user's eyes. Under the pulling action of the headband 63 and the right headband 64, the user can apply an axial pushing force to the inner barrel 12 around the eyes, and under the action of the pushing force, the first sliding part 121 slides from the starting end to the tail end of the guide rail 111, so that the VR device is switched from the light-shielding state to the light-transmitting state. In such an embodiment, along with the process that the user wears the VR display device through the left head band 63 and the right head band 64, the VR device can realize the non-inductive switching between the light-shielding state and the light-transmitting state without additional operation, thereby greatly improving the user experience.
When the VR device has the structure shown in fig. 2, when the user finishes using the VR device, the left head band 63 and the right head band 64 may be removed from the head, and the first slider 121 may be returned to the starting end of the guide rail 111 by rotating the inner barrel 12.
When the VR device is in the configuration shown in fig. 3 or 4, the left head band 63 and the right head band 64 can be removed from the head when the user finishes using the VR device. At this time, the user releases the axial pushing force applied to the second sliding member 18, and the elastic element 16 automatically contracts, so as to bring the first sliding member 121 back to the starting end of the guide rail 111. Under this condition, along with user's end use action, VR equipment has switched to the shading state from the printing opacity state automatically, does not need user's extra operation, and is very convenient, has greatly promoted user experience.
It should be understood that, besides the alternative embodiments described in the above embodiments, in a mechanical relative rotation structure, the guide rail extending along the non-axial direction may also be provided on the cylinder of the inner lens barrel, and in this case, the inner wall of the outer lens barrel is fixedly provided with the first sliding member adapted to the guide rail, and the first sliding member is inserted into the guide rail and slidably connected with the guide rail. This implementation manner is substantially the same as the technical solution of each embodiment of the present invention, and may be modified or replaced with reference to the embodiments described above, which are not described herein again.
The above embodiment describes an alternative embodiment in which the inner barrel 12 and the outer barrel 11 can be mechanically rotated relative to each other by a rail and a slider, and in addition to the embodiment described in the above embodiment, in another alternative embodiment, the outer barrel 11 and the inner barrel 12 are rotated relative to each other by a gear assembly.
As shown in fig. 7, in this embodiment, the VR device further includes: a front device case 71 and a rear device case 72 that is engaged with the front device case 71. The device front shell 71 comprises a lens frame 20, the lens frame 20 is provided with a through hole, and the outer lens barrel 11 is sleeved in the through hole; the lens frame 20 is further fixedly provided with a first gear assembly 201, and the outer cylinder wall of the outer lens barrel 11 is fixedly provided with a second gear assembly 113 engaged with the first gear assembly 201.
In consideration of the aesthetic effect, and effectively preventing the user from being scratched by the gear assembly when observing the image through the VR device, the second gear assembly 113 may be disposed at an end (end close to the object) of the outer barrel 11 away from the human eye.
When the VR device is in a use state, the outer barrel 11 can be driven to rotate by controlling the first gear assembly 201 to ensure that the polarization directions of the first polarizing film 13 and the second polarizing film 15 are the same; when the VR device is switched from the use state to the non-use state, the outer barrel 11 may be driven to rotate by any one of angles (not including 0 °) of 45 °, 60 °, 90 ° or 0-90 ° by controlling the first gear assembly 113 to ensure that the polarization directions of the first and second polarizing films 13 and 15 are different.
Alternatively, one way to drive the outer barrel 11 to rotate by controlling the first gear assembly 201 is a manual way. In this manner, to facilitate the user to control the first gear assembly 113, the present embodiment may provide a knob 114 on the lens frame 20. As shown in fig. 8, another through hole may be formed in the lens frame 20 at a position corresponding to the first gear assembly 201, and the knob 114 may be connected to the first gear assembly 201 through the through hole, so that the knob 114 faces the direction of the user, thereby facilitating the operation of the user. When the user rotates the knob 114, the first gear assembly 201 rotates therewith.
Alternatively, another way of driving the outer barrel 11 to rotate by controlling the first gear assembly 113 is an automatic way, which may adopt the structure shown in fig. 9. As shown in fig. 9, a VR device may have a motor 202, a sensor 203, and a control unit 204; wherein, the first gear assembly 201 is fixed on the motor 202 and can rotate along with the rotation of the motor 202; the sensor 203 is used for detecting whether a user touches or approaches; the control unit 204 is electrically connected with the sensor 203 and the motor 202, and is used for controlling the motor 202 to drive the first gear assembly 201 to rotate according to the detection result of the sensor 203. For example, the sensor 203 may detect a signal whether there is user contact or approach in real time and transmit the detected signal to the control unit 204 in real time. If the control unit 204 determines that the user approaches or touches the VR device according to the received signal, it may be considered that the VR device needs to enter a use state. At this time, a control signal may be sent out to control the first gear assembly 201 to rotate by a corresponding angle, so that the polarization directions of the first and second polarization films 13 and 15 are the same. If the control unit 204 determines that the user originally approaching or contacting the VR device leaves according to the received signal, it may be considered that when the VR device is switched from the use state to the non-use state, a control signal may be sent to control the first gear assembly 201 to rotate by a corresponding angle, so that the polarization directions of the first polarizing film 13 and the second polarizing film 15 are kept different.
Alternatively, the sensor 203 and the control unit 204 may be mounted on the apparatus front case 71, the apparatus rear case 72, or the lens barrel frame 20, which is not limited in this embodiment. Alternatively, in order to enable the human body sensor 203 to have high detection accuracy, the human body sensor 203 may be disposed at a position where the user can contact with the periphery of the user's eyes when using the VR device, for example, may be disposed on an end surface of the inner barrel 12 near the periphery of the user's eyes, or on the lens frame 20 near the forehead of the user.
In order to miniaturize and lighten VR equipment, a small stepping motor can be selected as the motor 202, and a micro control chip is adopted as the control unit 204. The sensor 203 may be an infrared sensor, a capacitive touch sensor, an image collector, or an optical sensor, which is not limited in this embodiment.
The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.