Patent Publication Number: US-2012026612-A1

Title: Compact imaging device

Description:
FIELD 
     The subject matter disclosed herein relates to an imaging device having a small form factor. 
     BACKGROUND 
     Many portable electronic apparatuses, such as a cellular phone and/or a personal digital assistant (PDA) for example, may comprise a compact camera module. Such a module may comprise an image sensor, an imaging lens assembly, and/or an actuator to adjust the position of the imaging lens assembly with respect to the image sensor. As designers push towards slimmer, smaller, and/or lighter portable electronic apparatuses, compact camera module manufacturers, among others, are facing a challenge of providing smaller compact camera modules that can fit into limited space of the apparatuses. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Non-limiting and non-exhaustive embodiments will be described with reference to the following objects, wherein like reference numerals refer to like parts throughout the various objects unless otherwise specified. 
         FIG. 1  is a perspective view of components that comprise a compact imaging module, according to an embodiment. 
         FIG. 2  is a perspective view of a compact imaging module, according to an embodiment. 
         FIG. 3  is a perspective view of a spring, according to an embodiment. 
         FIG. 4  is a top view of a spring, according to an embodiment. 
         FIG. 5  is a perspective view of a coil, according to an embodiment. 
         FIG. 6  is a top view of a coil, according to an embodiment. 
         FIG. 7  is a top view of a coil-spring component, according to an embodiment. 
         FIG. 8  is a perspective view of components that comprise a compact imaging module, according to another embodiment. 
         FIG. 9  is a side view of a compact imaging module, according to an embodiment. 
         FIG. 10  is a close-up view of an activated actuator, according to an embodiment. 
         FIG. 11  is a close-up view of a non-activated actuator, according to an embodiment. 
         FIG. 12  is a side view of a compact imaging module, according to another embodiment. 
         FIG. 13  is a close-up view of an activated actuator, according to an embodiment. 
         FIG. 14  is a close-up view of a non-activated actuator, according to an embodiment. 
         FIG. 15  is a perspective view of components that comprise a compact imaging module, according to one embodiment. 
         FIG. 16  is a perspective view of components that comprise a compact imaging module, according to another embodiment. 
         FIG. 17  is a perspective view of components that comprise a compact imaging module, according to still another embodiment. 
         FIG. 18  is a perspective view of components that comprise a compact imaging module, according to yet another embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, numerous specific details are set forth to provide a thorough understanding of claimed subject matter. However, it will be understood by those skilled in the art that claimed subject matter may be practiced without these specific details. In other instances, methods, apparatuses, or systems that would be known by one of ordinary skill have not been described in detail so as not to obscure claimed subject matter. 
     Reference throughout this specification to “one embodiment” or “an embodiment” may mean that a particular feature, structure, or characteristic described in connection with a particular embodiment may be included in at least one embodiment of claimed subject matter. Thus, appearances of the phrase “in one embodiment” or “an embodiment” in various places throughout this specification are not necessarily intended to refer to the same embodiment or to any one particular embodiment described. Furthermore, it is to be understood that particular features, structures, or characteristics described may be combined in various ways in one or more embodiments. In general, of course, these and other issues may vary with the particular context of usage. Therefore, the particular context of the description or the usage of these terms may provide helpful guidance regarding inferences to be drawn for that context. 
     Likewise, the terms, “and,” “and/or,” and “or” as used herein may include a variety of meanings that also is expected to depend at least in part upon the context in which such terms are used. Typically, “or” as well as “and/or” if used to associate a list, such as A, B or C, is intended to mean A, B, and C, here used in the inclusive sense, as well as A, B or C, here used in the exclusive sense. In addition, the term “one or more” as used herein may be used to describe any feature, structure, or characteristic in the singular or may be used to describe some combination of features, structures, or characteristics. Though, it should be noted that this is merely an illustrative example and claimed subject matter is not limited to this example. 
     Embodiments described herein include a compact imaging module that provides a mechanism and/or allows a process to adjust a distance between an imaging lens and an image sensor, wherein a footprint of the compact module may be substantially the same as or less than a footprint of the image sensor, for example. In other words, a surface area of a compact imaging module may not extend substantially beyond a surface area of an image sensor. Such a compact imaging module may provide an advantage to designers incorporating such a module into increasingly slimmer, smaller, and/or lighter portable electronic apparatuses, such as a compact camera, for example. 
     As used to describe such embodiments, terms “above”, “below”, and “side” described positions relative to an optical axis of such a compact imaging module. In particular, “above” and “below” refer to positions along an optical axis, wherein “above” refers to one side of an element and “below” refers to an opposite side of the element. Relative to such an “above” and “below”, “side” refers to a side of an element that is displaced from an optical axis, such as the periphery of a lens, for example. 
     In a particular embodiment, such a footprint may be achieved by arranging an actuator to be above and/or below a lens assembly, as opposed to arranging an actuator to surround sides of a lens assembly. In a particular embodiment, for example, a structure of a compact imaging module, such as a compact camera module, may provide auto-focus and/or other imaging functions, in which an actuator is mounted above and/or below an imaging lens. Such an actuator may also comprise a surface area that does not extend substantially beyond a surface area of an image sensor of the compact camera module. In comparison, for example, an actuator of a compact camera module situated on a side of such an imaging lens may result in a relatively larger imaging module profile. Such a relatively large profile may prohibit a compact camera module to have a footprint that is substantially equal to or smaller than a footprint of its image sensor. In one implementation, such an actuator may comprise a magnet and a coil to impart a magnetic force on a lens assembly. Such a magnet may have a flat or planar shape, such as the shape of a flat disk, for example. A magnet may be a permanent magnet or electromagnetic field generator, such as a coil, for example. Such a coil may be a wound coil, printed coil, and/or an electroplated coil on a substrate. A compact imaging module may comprise a spring to provide a restoring force to the lens assembly. 
     In other embodiments, a compact imaging module may include an actuator having a coil that moves with a lens assembly if the coil is energized. In another configuration, a compact imaging module may comprise an actuator having a coil and a magnet, wherein the magnet may move with a lens assembly if the coil is energized. 
     In one particular implementation, such an actuator may comprise four magnets that may be arranged in one plane. In another particular implementation, such an actuator may comprise four coils that may be arranged in one plane. Such four coils may be electrically connected in series or at least two of four coils may be electrically connected in parallel. In another particular implementation, such four coils may be mounted on and/or sit on a lens assembly of a compact imaging module. 
     In another embodiment, a compact imaging module may include an actuator comprising at least two sets of coils to produce an electromagnetic force, wherein each set of the coils is positioned in two parallel planes. In one particular implementation, such two sets of coils may be arranged substantially orthogonal to an optical axis of a lens assembly of the compact imaging module. In another particular implementation, one set of the two sets of coils may move with the lens assembly if the two sets of coils are energized, for example. Of course, such details of a compact imaging module are merely examples, and claimed subject matter is not so limited. 
     In an embodiment, a compact imaging module may result from mounting a lens assembly including one or more lenses to a portion of an actuator, and positioning an image sensor to receive light from the lens assembly, wherein the actuator may include a leaf spring that is between the image sensor and the lens assembly. In one implementation, such a compact imaging module may comprise a lens assembly, at least one actuator to adjust the position of the lens assembly, and an image sensor, wherein at least a portion of the actuator may be disposed between the lens assembly and the image sensor. For example, an actuator may comprise a leaf spring that is disposed between a lens assembly and an image sensor. In one particular implementation, such an actuator may comprise a magnet and a coil that are also disposed between a lens assembly and an image sensor. For example such an actuator may be mounted on the image sensor and/or the lens assembly may be mounted on the actuator. In another particular implementation, such an actuator may comprise a magnet and a coil that are disposed above a lens assembly while a leaf spring is disposed below the lens assembly. In either implementation, such an actuator may drive a lens assembly vertically to adjust the position of the lens assembly with respect to an image sensor. As used herein, “vertically” refers to a direction substantially parallel to an optical axis of a compact imaging module, whereas “horizontally” refers to a direction substantially perpendicular to an optical axis of a compact imaging module. Of course, such details of a compact imaging module are merely examples, and claimed subject matter is not so limited. 
     An actuator may provide a relatively precise control of motion of a lens assembly, so that various imaging functions, such as focusing for example, may lead to an improved image quality. An advantage of such a compact module is that its footprint may be substantially equal to or smaller than a footprint of an image sensor, so that a surface area of the compact module does not extend substantially beyond a surface area of the image sensor. Moreover, a batch manufacturing process may be applied to such a compact module that includes a properly designed actuator. Such a batch process may occur on a wafer level process, for example. Such a process may lead to a relatively high manufacturing efficiency, thus lowering manufacturing costs of a camera, for example, due to a focus variation function provided by the compact module. 
       FIG. 1  is a perspective view of components that comprise a compact imaging module, according to an embodiment. Such an imaging module may comprise an image sensor  110  having a ball grid array interface  115 , though such an imaging module may instead include a number of different types of electrical connections. Image sensor  110  may comprise an active region  117  including an array of pixilated charge-coupled devices (CCD) and/or one or more complementary metal-oxide-semiconductor (CMOS) devices, just to name a couple of examples. 
     In an embodiment, imaging module  100  may further comprise a lens assembly  160 , which may include one or more lenses to provide an image onto active region  117  of image sensor  110 . Such an image need not comprise visible wavelengths, but may also comprise infrared and/or ultraviolet wavelengths, for example. So that such an image is focused onto active region  117 , an actuator  135  may adjust a position of lens assembly  160  with respect to image sensor  110 . In a particular implementation, actuator  135  may adjust a vertical position of at least a portion of lens assembly  160  with respect to image sensor  110 . As mentioned above, such a lens assembly may comprise one or more lenses so that the vertical position of one or more of such lenses may be adjusted as a group. In a particular implementation, actuator  135  may comprise a magnet  130 , a leaf spring  140 , and/or a coil  150 . Imaging module  100  may further comprise a spacer  120  disposed between actuator  135  and image sensor  110 , for example. Though for the present embodiment actuator  135  is described as comprising components that are all arranged below lens assembly  160 , in another embodiment, as described in detail below, an actuator may comprise components that may be arranged to be above and/or below a lens assembly. 
       FIG. 2  is a perspective view of a compact imaging module  200 , according to an embodiment. Such a module may comprise compact imaging module  100  shown in  FIG. 1 . For example, compact imaging module  200  may comprise a casing  220  to cover components of compact imaging module  100 . Such a casing may be mounted on image sensor  110 , which may include ball grid array  210  for electrical connections between compact imaging module  200  and one or more system components (not shown) such as control circuitry or the like. 
       FIG. 3  is a perspective view of a spring  300  and  FIG. 4  is a top view of spring  300 , according to an embodiment. Such a spring may comprise a leaf spring such as leaf spring  140  shown in  FIG. 1 , for example. In one implementation, spring  300  may comprise a central portion  330  and an arm portion  320  adapted to move or flex as a spring. For example, central portion  330  and an arm portion  320  may provide a restoring force if central portion  330  and an arm portion  320  are displaced from a neutral configuration. A fixed portion  310  may comprise an outer portion of spring  300  which is fixedly mounted to one or more components of compact imaging module. For example, central portion  330  and arm portion  320  may flex in a spring-like manner while fixed portion  310  is held in a relatively fixed position. Spring  300  may further comprise an aperture  340  to allow light along an optical axis to travel past spring  300 . Of course, such details of spring  300  are merely examples, and claimed subject matter is not so limited. 
       FIG. 5  is a perspective view of a coil  500  and  FIG. 6  is a top view of coil  500 , according to an embodiment. Such a coil may comprise coil  150  shown in  FIG. 1 , for example. In one implementation, a lens assembly, such as lens assembly  160  shown in  FIG. 1 , may be mounted to coil  500 , comprising a conductor  520  mounted on a substrate  510 . Conductor  520  may comprise multiple loops of wire in one or more layers of substrate  510 . An electrical current travelling through such loops of conductor  520  may induce a magnetic field to impart a force on a magnet, such as magnet  130  shown in  FIG. 1 , for example. In such a case, spring  140  may provide a restoring force to counter such a magnetic force, thereby providing a mechanism to adjust a vertical position of lens assembly  160  with respect to image sensor  110 . Coil  500  may further comprise an aperture  530  to allow light along an optical axis to travel past coil  500 . Of course, such details of coil  500  are merely examples, and claimed subject matter is not so limited. 
     In one embodiment, a spring and a coil may be combined as one component, and  FIG. 7  is a top view of an example of such a coil-spring component  700 . A spring portion of such a combined component may provide electrical current to a coil portion, for example. For example, such a combined component may comprise a coil  710  and an electrode  720 , which may also comprise a leaf spring, to conduct electrical current from an external source (not shown) to coil  710 . Portions  730  and  740  show connection areas where electrical current may be transferred from conductor  720  to coil  710  or vise versa. 
       FIG. 8  is a perspective view of components that comprise a compact imaging module  800 , according to an embodiment that may incorporate coil-spring component  700 . Such an imaging module may comprise an image sensor  810 , which may be similar to image sensor  110  shown in  FIG. 1 , for example. Imaging module  800  may further comprise a lens assembly  860 , which may include one or more lens units to provide an image onto an active region (not shown) of image sensor  810 . Such an image need not comprise visible wavelengths, but may also comprise infrared and/or ultraviolet wavelengths, for example. So that such an image is focused onto image sensor  810 , an actuator  835  may adjust a vertical position of lens assembly  860  with respect to image sensor  810 . Described in another way, actuator  835  may adjust a distance between lens assembly  860  and image sensor  810  to adjust a focus. Such a lens assembly may comprise one or more lenses so that the vertical position of one or more of such lenses may be adjusted. In a particular implementation, actuator  835  may comprise a magnet  830 , a spring-conductor  840 , and/or a coil  850 . As described above, spring-conductor  840  and coil  850  may comprise a single component such as coil-spring component  700  shown in  FIG. 7 . In such a single component, spring-conductor  840  may provide electrical current to coil  850 . Imaging module  800  may further comprise a spacer  820  disposed between actuator  835  and image sensor  810 , for example. Coil  850  is attached to lens assembly  860 . If energized, a magnetic field produced by electric current flowing in coil  850  interacting with magnet  830  positioned below coil  850  may provide a force to move lens assembly  860  and coil  850  along the optical axis. In another configuration, magnet  830  may be positioned above coil  850 . Of course, such details of a compact imaging module are merely examples, and claimed subject matter is not so limited. 
       FIG. 9  is a side view of a compact imaging module  900 , according to an embodiment. Such an imaging module may comprise an image sensor  910 , which may be similar to image sensor  110  shown in  FIG. 1 , for example. Imaging module  900  may further comprise a lens assembly  960 , which may include one or more lens units  970  to provide an image onto an active region (not shown) of image sensor  910 . As mentioned above, such an image need not comprise visible wavelengths, but may also comprise infrared and/or ultraviolet wavelengths, for example. So that such an image is focused onto image sensor  910 , an actuator may adjust a position of lens assembly  960  with respect to image sensor  910 . Such positioning is depicted by arrow  980 , for example. Such an actuator, which is disposed below lens assembly  960 , may comprise a magnet  930 , a leaf spring  940 , and a coil  950 . Such a lens assembly may comprise one or more lenses, as described in further detail below, so that the vertical position of one or more of such lenses may be adjusted. In a particular implementation, compact imaging module  900  may further comprise a spacer  920  disposed between magnet  930  and image sensor  910 , for example. Image sensor  910  may comprise ball grid array  912  for electrical connections to one or more external components (not shown). 
     Portion  990  depicts a region of compact imaging module  900  that may vary in configuration in response to actuator operation. Example configurations of portion  990  are shown in detail in  FIGS. 10 and 11 . Spacer  920  is not shown in  FIGS. 10 and 11  for clarity. As shown in  FIG. 10 , such an actuator may be activated if, for example, an electrical current travels through coil  950 . Such a current may induce a magnetic field o produce a repulsive force with respect to magnet  930 . Accordingly, a lens assembly  960  mounted on coil  950  may move away from magnet  930  to increase a distance between lens assembly  960  and an image sensor  910  substantially along a direction depicted by arrow  980 . Meanwhile, a leaf spring  940  may be attached to coil  950  to apply a restoring force to coil  950 . 
     In  FIG. 11 , such an actuator may be non-activated if, for example, there is no electrical current travelling through coil  950 . Lacking such a current, there may be no magnetic field to produce a repulsive force with respect to magnet  930 . Accordingly, a lens assembly  960  mounted on coil  950  may remain close to magnet  930  to maintain a distance between lens assembly  960  and an image sensor  910 . Such examples are limited to an actuator that is activated or not activated. Alternatively, an actuator may involve varying degrees of activation based, at least in part, on a varying magnitude of electrical current travelling in a coil  950 . Such varying degrees of activation may provide varying distances between lens assembly  960  and an image sensor  910  to precisely control a focus of light onto image sensor  910 . For example, a distance between lens assembly  960  and image sensor  910  may be based, at least in part, on a magnetic field, wherein such a distance is measured along an optical axis of a lens assembly. Of course, such details of a compact imaging module are merely examples, and claimed subject matter is not so limited. 
       FIG. 12  is a side view of a compact imaging module  905 , according to an embodiment. Such an imaging module may comprise an image sensor  915 , which may be similar to image sensor  910  shown in  FIG. 9 , for example. Imaging module  905  may further comprise a lens assembly  965 , which may include one or more lens units  975  to provide an image onto an active region (not shown) of image sensor  915 . In one particular implementation, lens assembly  965  may comprise at least a portion of a lens  977  that extends beyond one or more actuator elements such as a magnet  935  and a coil  955 . Magnet  935  may be supported by a magnet supporting unit  936 . So that such an image is focused onto image sensor  915 , an actuator may adjust a position of lens assembly  965  with respect to image sensor  915 . Such positioning is depicted by arrow  985 , for example. A portion of such an actuator that is disposed below lens assembly  965  may comprise a leaf spring  945 , whereas another portion disposed above at least a portion of lens assembly  965  may comprise magnet  935  and coil  955 . Such a lens assembly may comprise one or more lenses, and the vertical position of one or more such lenses may be adjusted as a group by an actuator. In a particular implementation, compact imaging module  905  may further comprise a spacer  925  disposed between leaf spring  945  and image sensor  915 , for example. Image sensor  915  may comprise ball grid array  914  for electrical connections to one or more external components (not shown). 
     Portion  995  depicts a region of compact imaging module  905  that may vary in configuration in response to actuator operation. Example configurations of portion  995  are shown in detail in  FIGS. 13 and 14 . In a particular implementation, an actuator may be activated if, for example, an electrical current travels through coil  955 . Such a current may induce a magnetic field to produce a repulsive force with respect to magnet  935 . Accordingly, a lens assembly  965  mounted below coil  955  may move away from magnet  935  to decrease a distance between lens assembly  965  and an image sensor  915  substantially along a direction depicted by arrow  988 . Meanwhile, a leaf spring  945  may be attached to a bottom portion of lens assembly  965  to apply an upward restoring force to lens assembly  965 . In another particular implementation, an actuator may be activated by an electrical current travelling through coil  955  to induce a magnetic field producing an attractive force with respect to magnet  935 . Accordingly, a lens assembly  965  mounted below coil  955  may move toward magnet  935  to increase a distance between lens assembly  965  and an image sensor  915  substantially along a direction depicted by arrow  988 . In still another particular implementation, an actuator may be non-activated if, for example, there is no electrical current travelling through coil  955 . Lacking such a current, there may be no magnetic field to produce a repulsive or attractive force with respect to magnet  930 . Accordingly, a lens assembly  965  mounted below coil  955  may remain close to magnet  935  to maintain a distance between lens assembly  965  and an image sensor  915 . Such examples are limited to an actuator that is activated or not activated. Alternatively, an actuator may involve varying degrees of activation based, at least in part, on a varying magnitude of electrical current travelling in a coil  955 . Such varying degrees of activation may provide varying distances between lens assembly  965  and an image sensor  915  to precisely control a focus of light onto image sensor  915 . Of course, such details of a compact imaging module are merely examples, and claimed subject matter is not so limited. 
       FIG. 15  is a perspective view of components that comprise a compact imaging module  170 , according to one embodiment. A coil component  171  may comprise a multiple number of individual coils  172 . In a particular implementation, coil component  171  may comprise four such coils  172 , which may be positioned in a single plane. Compact imaging module  170  may also comprise multiple individual magnets  174 . For example, compact imaging module  170  may comprise four such magnets, which may have a one-to-one correspondence with four coils  172 , though claimed subject matter is not so limited. 
       FIG. 16  is a perspective view of components that comprise a compact imaging module  175 , according to another embodiment. A magnet  177  may be disposed between a spring component  178  and a lens assembly  176 . In addition, one or more coils  179  may be disposed between spring component  178  and image sensor  173 . Such an arrangement may be compared with the embodiment shown in  FIG. 1 , for example. Magnet  177  may be attached to lens assembly  176 . If energized, a magnetic field produced by electric current flowing in coil  179  positioned below magnet  177  interacting with the magnet  177  may provide a force to move lens assembly  176  and magnet  177  along the optical axis. In another configuration, coil  179  may be positioned above magnet  177 , though claimed subject matter is not so limited. 
       FIG. 17  is a perspective view of components that comprise a compact imaging module  180 , according to still another embodiment. One or more coils  184  may be mounted and/or directly coated on a lens assembly surface  182 , though claimed subject matter is not so limited. 
       FIG. 18  is a perspective view of components that comprise a compact imaging module  185 , according to yet another embodiment. Such a module may include coil  187  and/or coil  189  in place of magnets that are otherwise included in other embodiments described above. 
     One skilled in the art will realize that a virtually unlimited number of variations to the above descriptions is possible, and that the examples and the accompanying figures are merely to illustrate one or more particular implementations. 
     While there has been illustrated and described what are presently considered to be example embodiments, it will be understood by those skilled in the art that various other modifications may be made, and equivalents may be substituted, without departing from claimed subject matter. Additionally, many modifications may be made to adapt a particular situation to the teachings of claimed subject matter without departing from the central concept described herein. Therefore, it is intended that claimed subject matter not be limited to the particular embodiments disclosed, but that such claimed subject matter may also include all embodiments falling within the scope of the appended claims, and equivalents thereof.