Patent Publication Number: US-2023164415-A1

Title: Camera for a portable electronic device with optical image stabilization

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Application No. PCT/CN2020/102736, filed on Jul. 17, 2020, the subject matter of which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to optical imaging devices in general. More specifically, the disclosure relates to a camera and an electronic device with such a camera for capturing an image, such as a smartphone, tablet computer and the like with improved optical image stabilization. 
     BACKGROUND 
     Portable electronic devices such as smartphones or tablet computers may include a camera for recording digital images. The digital images may include still images (photos) as well as motion pictures (video). The camera may comprise folded optics. These can have a relatively long focal length (e.g., for portrait or telephotography). More specifically, the camera may comprise a first lens group, a mirror and second lens group, the two lens groups having optical axes that are angled relative to each other, e.g., by a 90 degrees angle. 
     A problem exists in that camera shake can lower the resolution of the resulting images, especially when the camera optics have a longer focal length. Camera shake is unintended motion of the camera, e.g., when the camera is operated hand-held. 
     A simple but often unfeasible way of avoiding camera shake is to mount the camera on a tripod. Another solution is a class of techniques known as image stabilisation (IS). 
     There is a need for reducing shake effects in images generated by folded optics, e.g., in smartphones. 
     SUMMARY 
     It is an object to provide image stabilization for folded optics, especially for folded optics in a photographic camera, and more particularly for a camera in a smartphone, tablet computer or other portable device. 
     The foregoing and other objects are achieved by the subject matter of the independent claims. Further implementation forms are apparent from the dependent claims, the description and the figures. 
     Generally, embodiments provide a new optical image stabilization ( 01 S) scheme that enables stable performance of telephoto lenses of a tele camera in an electronic handheld device without tripod mounting or the necessity of large image sensors. Embodiments overcome the stability limits of a tele camera in an electronic handheld device and solve the problem of high-angle image stabilization of digital telephoto camera zoom lenses with high magnification that are suitable to be implemented in a modern smartphone. 
     More specifically, according to a first aspect a camera is provided. The camera comprises a housing, a first lens assembly comprising one or more lenses and having a first optical axis and a second lens assembly comprising one or more lenses and having a second optical axis. As used herein, a lens assembly may comprise one or more lens groups. A lens group comprises one or more lenses that are fixed relative to each other, e.g., a lens group can be moved only as a whole. 
     Moreover, the camera comprises a mirror placed at a point of intersection of the first optical axis and the second optical axis and an image sensor placed on the second optical axis. The first lens assembly is configured to receive light from outside the camera and to transmit the received light toward the mirror. The mirror is configured to receive light from the first lens assembly and to reflect the received light toward the second lens assembly. The second lens assembly is configured to receive light from the mirror and to transmit the received light toward the image sensor. 
     The camera further comprises an image stabilisation, IS, apparatus, wherein the IS apparatus comprises a first detector configured to generate a first signal in response to a rotation of the camera about an axis that is perpendicular to both the first optical axis and the second optical axis. Moreover, the IS apparatus comprises a first actuator configured to rotate the first lens assembly relative to the housing about a first rotation axis by a an angle α in response to the first signal and at the same time rotate the mirror about the first rotation axis by an angle α/2, wherein the first rotation axis is perpendicular to both the first optical axis and the second optical axis and passes through the point of intersection of the first optical axis and the second optical axis. Thus, advantageously, the first actuator allows reducing the effects of a shaking motion of the camera housing by adjusting the angle, e.g., the “pitch angle” between the first optical axis and the second optical axis. 
     In one embodiment, the IS apparatus further comprises a second detector configured to generate a second signal in response to a rotation of the camera about an axis identical with or parallel to the second optical axis and a second actuator configured to rotate a rotatable group of components relative to the housing about the second optical axis, wherein the rotatable group of components includes the first lens assembly, the mirror, and the second lens assembly. Thus, advantageously, the second actuator allows reducing the effects of a shaking motion of the camera housing by adjusting a “yaw angle” of the rotatable group of components relative to the camera housing. 
     In one embodiment, the rotatable group of components further includes the image sensor. 
     In one embodiment, the image sensor is fixed relative to the housing. Thus, in embodiment, the second actuator is configured to rotate the rotatable group of components relative to the camera housing and the image sensor. 
     In one embodiment, the IS apparatus further comprises a third detector configured to generate a third signal in response to a rotation of the camera about an axis that is perpendicular to both the first rotation axis and the second optical axis and a third actuator configured to rotate the image sensor relative to the housing about the second optical axis. Thus, advantageously, the third actuator allows reducing the effects of a shaking motion of the camera housing by adjusting a “roll angle” of the image sensor relative to the camera housing. 
     In one embodiment, the first lens assembly comprises a cemented achromatic lens comprising at least two different optical materials out of the choice of: glass, thermal plastics, UV-curable polymer, or Sol-Gel. 
     In one embodiment, the one or more lenses of the first lens assembly are fixed relative to each other. 
     In one embodiment the second lens assembly comprises a first lens group and a second lens group, wherein the first and the second lens group each comprise one or more lenses. 
     In one embodiment, one or both of the first and the second lens group have a positive refractive power. 
     In one embodiment, the first lens group has a positive refractive power and the second lens group has a negative refractive power, or vice versa. 
     In one embodiment, the camera further comprises focusing means for adjusting an axial position of the second lens group relative to the image sensor. As already described above, the lenses of the second lens group are immobile, i.e. fixed relative to each other. 
     In one embodiment, the IS apparatus is connected to the image sensor and is configured to perform IS based on object tracking. 
     According to a second aspect a portable electronic device is provided, wherein the portable electronic device comprises a camera according to the first aspect. The portable electronic device according to the second aspect may be, for instance, a smartphone, a tablet computer or other portable electronic device such as a drone, an augmented reality (AR) headset or a virtual reality (VR) headset. 
     Thus, embodiments provide an enhanced optical image stabilization (OIS) that is able to reach a correction angle up to 5 degree or even more. This value is comparable with a full field of view of 10 degrees in a tele camera. 
     Embodiments achieve high correction angles via this enhanced optical image stabilization (OIS), while totally holding the same image quality compared to the zero-angle imaging without any performance reduction. 
     Details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description, drawings, and claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following embodiments are described in more detail with reference to the attached figures and drawings, in which: 
         FIG.  1    is diagram illustrating an imaging lens system of a camera according to an embodiment; 
         FIG.  2 A  is a diagram illustrating an imaging lens system of a camera according to an embodiment with horizontal angle adjustment for optical image stabilization; 
         FIG.  2 B  is a diagram illustrating an imaging lens system of a camera according to an embodiment with horizontal angle adjustment for optical image stabilization; 
         FIG.  2 C  is a diagram illustrating an imaging lens system of a camera according to an embodiment with horizontal angle adjustment for optical image stabilization; 
         FIG.  3 A  is a diagram illustrating an imaging lens system of a camera according to an embodiment with vertical angle adjustment for optical image stabilization; 
         FIG.  3 B  is a diagram illustrating an imaging lens system of a camera according to an embodiment with vertical angle adjustment for optical image stabilization; 
         FIG.  3 C  is a diagram illustrating an imaging lens system of a camera according to an embodiment with vertical angle adjustment for optical image stabilization; 
         FIG.  4    is a diagram illustrating an imaging lens system of a camera according to an embodiment; 
         FIG.  5    is a diagram illustrating an imaging lens system of a camera according to an embodiment; 
         FIG.  6    is a diagram illustrating a three-dimensional view of an imaging lens system of a camera according to an embodiment; 
         FIGS.  7 A and  7 B  are diagrams illustrating an imaging lens system of a camera according to an embodiment with a pitch angle adjustment for optical image stabilization; 
         FIGS.  8 A and  8 B  are diagrams illustrating an imaging lens system of a camera according to an embodiment with a roll angle adjustment for optical image stabilization; and 
         FIG.  9    shows a table listing exemplary aspherical lens parameters of an imaging lens system of a camera according to an embodiment. 
     
    
    
     In the following identical reference signs refer to identical or at least functionally equivalent features. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     In the following description, reference is made to the accompanying figures, which form part of the disclosure, and which show, by way of illustration, specific aspects of embodiments of the disclosure or specific aspects in which embodiments of the present disclosure may be used. It is understood that embodiments may be used in other aspects and comprise structural or logical changes not depicted in the figures. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims. 
     For instance, it is to be understood that a disclosure in connection with a described method may also hold true for a corresponding device or system configured to perform the method and vice versa. For example, if one or a plurality of specific method operations are described, a corresponding device may include one or a plurality of units, e.g. functional units, to perform the described one or plurality of method operations (e.g. one unit performing the one or plurality of operations, or a plurality of units each performing one or more of the plurality of operations), even if such one or more units are not explicitly described or illustrated in the figures. On the other hand, for example, if a specific apparatus is described based on one or a plurality of units, e.g. functional units, a corresponding method may include one operation to perform the functionality of the one or plurality of units (e.g. one operation performing the functionality of the one or plurality of units, or a plurality of operations each performing the functionality of one or more of the plurality of units), even if such one or plurality of operations are not explicitly described or illustrated in the figures. Further, it is understood that the features of the various exemplary embodiments and/or aspects described herein may be combined with each other, unless specifically noted otherwise. 
       FIG.  1    is a diagram illustrating the architecture of an imaging lens system  100  of a camera for an electronic device such as a smartphone, a tablet computer, any other portable electronic device or the like according to an embodiment. As will be described in more detail below, the camera comprises a housing, a first lens assembly  101  comprising one or more lenses and having a first optical axis A (illustrated, for instance, in  FIGS.  2 A-C ) and a second lens assembly  105 ,  107  comprising one or more lenses and having a second optical axis B (illustrated, for instance, in  FIGS.  2 A-C ). As used herein, a lens assembly may comprise one or more lens groups, wherein a lens group comprises one or more lenses that are fixed relative to each other, e.g., a lens group can be moved only as a whole. For instance, in the embodiment shown in  FIG.  1   , the second lens assembly  105 ,  107  comprises a first lens group  105  and a second lens group  107 , wherein each of the first lens group  105  and the second lens group  107  comprises one or more lenses. 
     Moreover, the camera comprises a mirror  103  placed at a point of intersection of the first optical axis A and the second optical axis B and an image sensor  109  placed on the second optical axis B. The first lens assembly  101  is configured to receive light from outside the camera and to transmit the received light toward the mirror  103 . The mirror  103  is configured to receive light from the first lens assembly  101  and to reflect the received light toward the second lens assembly  105 ,  107 . The second lens assembly  105 ,  107  is configured to receive light from the mirror  103  and to transmit the received light toward the image sensor  109 . As will be appreciated, for instance, from  FIGS.  2 A-C , the first lens assembly  101  defining the first optical axis A and the second lens assembly  105 ,  107  defining the second optical axis B are arranged in a folded configuration. 
     The camera further comprises an image stabilisation, IS, apparatus, wherein the IS apparatus comprises a first detector configured to generate a first signal in response to a rotation of the camera about an axis that is perpendicular to both the first optical axis A and the second optical axis B. In an embodiment, the first detector may comprise, for instance, a gyro sensor and/or an acceleration sensor. 
     Moreover, the IS apparatus comprises a first actuator configured to rotate the first lens assembly  101  relative to the housing about a first rotation axis by a an angle α in response to the first signal and at the same time rotate the mirror  103  about the first rotation axis by an angle α/2, wherein the first rotation axis is perpendicular to both the first optical axis A and the second optical axis B and passes through the point of intersection of the first optical axis A and the second optical axis B. Thus, advantageously, the first actuator allows reducing the effects of a shaking motion of the camera housing by adjusting the angle, e.g., the “pitch angle” between the first optical axis A and the second optical axis B. 
     In an embodiment, the first lens assembly  101  comprises a hybrid glass/plastic bump lens. In another embodiment, the first lens assembly  101  comprises a cemented achromatic lens comprising, i.e. made of at least two different optical materials out of the choice of: glass, thermal plastics, UV-curable polymer, or Sol-Gel. 
     In an embodiment, the first lens assembly  101  has a positive refractive power, the first lens group  105  of the second lens assembly has a negative refractive power and the second lens group  107  of the second lens assembly has a positive refractive power. In another embodiment, the first lens assembly  101  has a positive refractive power, the first lens group  105  of the second lens assembly has a positive refractive power and the second lens group  107  of the second lens assembly has a negative refractive power. In a further embodiment, the first lens assembly  101  has a positive refractive power, the first lens group  105  of the second lens assembly has a positive refractive power and the second lens group  107  of the second lens assembly has a positive refractive power. 
     As can be seen in  FIGS.  2 A,  2 B and  2 C  below, the first optical axis (along which the first lens assembly  101  receives light; illustrated as first optical axis “A” in  FIGS.  2 A,  2 B and  2 C ) and the second optical axis (defined by the second lens assembly  105 ,  107 ; illustrated as second optical axis “B” in  FIGS.  2 A,  2 B and  2 C ) define an optical plane and intersect at an angle at an intersection point within the optical plane. As already described above, the mirror  103  is configured to transform, e.g. reflect, light propagating along the first optical axis A into light propagating along the second optical axis B. The image sensor  109  is configured detect light propagating along the second optical axis B. 
     As already described above, the first actuator of the IS apparatus is configured to rotate the first lens assembly  101  relative to the second lens assembly  105 ,  107  around a first rotation axis for adjusting the angle, i.e. the “pitch angle” between the first optical axis A and the second optical axis B, wherein the first rotation axis extends perpendicularly to the optical plane through the intersection point (i.e. perpendicular to the cross-sectional planes shown in  FIGS.  2 A,  2 B and  2 C ). 
     In an embodiment, the IS apparatus may further comprise a second detector configured to generate a second signal in response to a rotation of the camera about an axis identical with or parallel to the second optical axis B. Like the first detector, the second detector may comprise, for instance, a gyro sensor and/or an acceleration sensor. In this embodiment, the IS apparatus further comprises second actuator configured to rotate a rotatable group of components relative to the housing of the camera about the second optical axis B, wherein the rotatable group of components includes the first lens assembly  101 , the mirror  103 , and the second lens assembly  105 ,  107 . Thus, advantageously, the second actuator allows reducing the effects of a shaking motion of the camera housing by adjusting a “yaw angle” of the rotatable group of components, i.e. the first lens assembly  101 , the mirror  103 , and the second lens assembly  105 ,  107  as a whole, relative to the camera housing. In an embodiment, the rotatable group of components may further include the image sensor  109 . In other words, in an embodiment, the second actuator is configured to rotate the first lens assembly  101 , the mirror  103 , the second lens assembly  105 ,  107  and the image sensor  109  as a whole relative to the camera housing. 
     In a further embodiment, the image sensor  109  may be fixed to the camera housing. Thus, in this embodiment the second actuator is configured to rotate the rotatable group of components, e.g., the first lens assembly  101 , the mirror  103 , and the second lens assembly  105 ,  107 , relative to the camera housing and the image sensor  109 . 
     In a further embodiment, the IS apparatus further comprises a third detector configured to generate a third signal in response to a rotation of the camera about an axis that is perpendicular to both the first rotation axis A and the second optical axis B. Like the first and the second detector, the third detector may comprise, for instance, a gyro sensor and/or an acceleration sensor. Moreover, the IS apparatus may comprise a third actuator configured to rotate the image sensor  109  relative to the camera housing about the second optical axis B. Thus, advantageously, the third actuator allows reducing the effects of a shaking motion of the camera housing by adjusting a “roll angle” of the image sensor  109  relative to the camera housing. 
     In an embodiment, the camera further comprises focusing means (such as a linear motor) for adjusting an axial position of the second lens group  107  relative to the image sensor  109 . As already described above, the lenses of the second lens group  107  are immobile, i.e. fixed relative to each other. 
     In an embodiment, the IS apparatus is connected to the image sensor  109  and is configured to perform IS based on object tracking and to control the plurality of actuators based on the object tracking. 
     Embodiments of the disclosure apply a variable angle folding and rotating of a periscope-type optics, wherein the front lens/bump optics always points directly into the direction of the object. In an embodiment, the alignment of the front lens being part of the first lens assembly  101  is achieved by a combined angle and rolling adjustment of the camera optics that includes a certain angle adjustment of the bump optics and of the folding optics respectively. 
     To always directly point the front lens being part of the first lens assembly  101  to the object, the optical image stabilization (optical IS) according to an embodiment is split into two independent angle adjustments, namely the roll angle adjustment in a vertical direction and the pitch angle adjustment in a horizontal direction of the optical IS. 
       FIGS.  2 A,  2 B and  2 C  show an example of the pitch or horizontal angle adjustment with 0°, 10° and 20° for the optical image stabilization respectively. The horizontal adjustment of the optical IS consists of an adjustable periscope optics including a variable front lens angle combined with a variable folding optics angle in a way that the folding optics is adjusted at exactly half the angle of the front lens (or  2 : 1  if measured with the front lens angle respectively). 
     As already described above, an imaging lens system  200  is shown in  FIGS.  2 A,  2 B and  2 C , wherein the imaging lens system  200  comprises: a first lens assembly  101  configured to receive light via the aperture from outside of the housing along the first optical axis A; a second lens assembly  105 ,  107  defining the second optical axis B; a mirror  103  arranged between the first lens assembly  101  and the second lens assembly  105 ,  107 ; and an image sensor  109  arranged along the second optical axis B behind the second lens assembly  105 ,  107 . As in the embodiment shown in  FIG.  1   , the second lens assembly  105 ,  107  comprise a first lens group  105  and a second lens group  107  arranged on the second optical axis B between the mirror  103  and the image sensor  109 . 
     As can be seen from  FIGS.  2 A,  2 B and  2 C , by means of the first detector and the first actuator of the IS apparatus the first lens assembly  101  is configured to be rotated relative to the second lens assembly  105 ,  107  around the first rotation axis by a first rotation angle α and the reflecting mirror  103  is configured to be rotated around the first rotation axis by a second rotation angle β, wherein the first rotation angle α is twice as large as the second rotation angle β, i.e. α=2*β. 
       FIGS.  3 A,  3 B and  3 C  show an example of the roll or vertical angle adjustment with 0°, 10° and 20° for the optical image stabilization respectively effected by the second detector and the second actuator of the IS apparatus. The roll or vertical angle adjustment of the optical IS consists of a rotational orientation of the periscope optics group around the second optical axis B in a way that the resulting adjustment angle matches exactly the necessary angle for the optical IS. 
     In an embodiment, the combined function of the system rotation and the  2 : 1  angle matching of the front lens being part of the first lens assembly  101  and folding optics achieves an optical performance and image quality that is basically independent of the actual amount of the IS adjustment. Therefore, the maximum angle for the optical IS is only limited by the mechanical layout of the housing. 
     As can be seen from  FIGS.  3 A,  3 B and  3 C  and as already described above, the first lens assembly  101 , the mirror  103 , and the second lens assembly  105 ,  107  are rotated as a whole around the second rotation axis B for adjusting the “roll angle” of the first lens assembly  101 , the mirror  103 , and the second lens assembly  105 ,  107  relative to the housing, wherein the second rotation axis B corresponds to the second optical axis B, i.e. wherein the second rotation axis B and the second optical axis B are the same. 
     In addition to the vertical and horizontal image stabilization by the above described optical IS provided by the IS apparatus, there is furthermore a possibility to additionally rotate the image sensor  109  around the second rotation axis B, as already described above. This also stabilizes the unintended image shaking due to any possible camera rotation that can happen beside the vertical and horizontal misalignment. 
     Embodiments of the disclosure can perfectly adjust to any possible device shaking that happens within a certain limit, e.g., 5°, which corresponds to the optomechanical layout of the device. 
     Furthermore, embodiments of the disclosure may implement a beam impander that concentrates the light into the folded periscope optics by the use of a front lens with a positive optical power.  FIG.  4    illustrates a further embodiment of the camera including a beam impander provided by the first lens assembly  101 , the mirror  103  and the first lens group  105  of the second lens assembly. 
     As shown in  FIG.  4   , the first lens assembly  101  has a positive refractive power, the first lens group  105  of the second lens assembly has a negative refractive power and the second lens group  107  of the second lens assembly has a positive refractive power. 
     This enables a lower F-Number and splits the imaging lens system  400  into a principle front part (e.g., the beam impander)  401  and a rear part  403 , wherein the front part  401  includes the first lens assembly  101 , the folding optics, i.e. the mirror  103  and the first lens group  105  of the second lens assembly after the folding and the rear part  403  includes the focusing optics group, i.e. the second lens group  107  of the second lens assembly that focuses the light onto the image sensor  109 . 
     Alternatively,  FIG.  5    shows another imaging lens system  500  of the camera according to an embodiment, wherein the focusing lens can also be implemented in the front optics part  501 , which is followed by a lens with negative optical power, enabling auto focus (AF) within the system. As can be seen from  FIG.  5   , the first lens assembly  101  has a positive refractive power, the first lens group  105  of the second lens assembly has a positive refractive power and the second lens group  107  of the second lens assembly has a negative refractive power. 
       FIG.  6    shows a three-dimensional perspective view of the imaging lens system  600  of the camera according to an embodiment with a magnification power of ten times (e.g., M10x) which is suitable to be implemented into a modern smartphone according to an embodiment, wherein the total system length is 22 mm and the camera module achieves a f-number of F2.96. 
     The imaging lens system  600  of the telephoto camera consists of the lens assemblies, e.g., groups  101 ,  105 ,  107 , the folding mirror  103  and the image sensor  109 . The light enters through the first optical lens assembly  101  which may comprise a hybrid glass/plastic lens. The first lens assembly  101  has positive optical refractive power and is located in front of the folding mirror  103 . In an initial state the angle of the folding mirror  103  is 45° while the angle of the first lens assembly  101  is 90°. The first lens group  105  of the second lens assembly comprises three plastic lenses and is located directly behind the folding mirror  103 . The first lens group  105  has also a positive optical refractive power. The second lens group  107  of the second lens assembly may also comprise three plastic lenses and is located in front of the image sensor  109 . The second lens group  107  of the second lens assembly has a negative optical refractive power. The second optical lens group  107  of the second lens assembly can move along the second optical axis B to enable near imaging for the auto focus function of the camera. 
     As can be seen from  FIG.  6   , the cross sections of the lenses have been shaped in a special aperture cut, in order to fit the lenses into the mechanical high of the smartphone. 
       FIGS.  7 A and  7 B  demonstrate the optical imaging system  600  of the telephoto camera shown in  FIG.  6    with a pitch or horizontal angle adjustment of 5° within the camera body for the optical image stabilization in the same way as described above under reference to  FIGS.  2 A,  2 B and  2 C . As described above, by means of the first detector and the first actuator of the IS apparatus the positions of the first lens assembly  101  and of the first lens group  105  of the second lens assembly as well as of the folding mirror  103  are adjusted to compensate for horizontal image deviation. 
       FIGS.  8 A and  8 B  further demonstrate the imaging lens system  600  of the telephoto camera shown in  FIG.  6    with a roll or vertical angle adjustment of 5° within the camera body for the optical image stabilization in the same way as described above under reference to  FIGS.  3 A,  3 B and  3 C . As can be seen from  FIGS.  8 A and  8 B , the imaging lens system  600  is rolled around the second optical axis B relative to the housing to compensate for vertical image shaking. In other words, the first lens assembly  101 , the mirror  103 , the second lens assembly  105 ,  107  and the image sensor  109  are rotated as a whole around the second rotation axis B. As already described above, in a further embodiment, the image sensor  109  may be fixed to the camera housing and thereby decoupled form this rolling motion of the first lens assembly  101 , the mirror  103 , and the second lens assembly  105 ,  107 . 
     The above adjustments from all optical image stabilization ( 01 S) components combined can achieve a complete and highly effective image stabilization over a range of +/−5° degree in both, vertical and horizontal, directions. 
       FIG.  9    shows a table  900  listing exemplary aspherical lens parameters of the imaging lens system  100  of  FIG.  1    in a telephoto camera according to an embodiment in a standard sequential surface matrix, including for instance the surface type, the radius, the thickness, the refractive index/the Abbe number, the asphere coefficients of the different lens surfaces of the imaging lens system of  FIG.  1   . 
     In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the described apparatus embodiment is merely exemplary. For example, the unit division is merely logical function division and may be other division in actual implementation. For example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented by using some interfaces. The indirect couplings or communication connections between the apparatuses or units may be implemented in electronic, mechanical, or other forms. 
     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 position, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments. 
     In addition, functional units in the embodiments of the disclosure may be integrated into one processing unit, or each of the units may exist alone physically, or two or more units may be integrated into one unit.