Patent Publication Number: US-2013229571-A1

Title: Optimized designs for embedding webcam modules with superior image quality in electronics displays

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims the benefit of, and priority to, U.S. provisional application No. 61/015,112, entitled “Optimized Designs for Embedding Webcam Modules in Electronic Displays”, filed on Dec. 19, 2007, and is hereby incorporated herein in its entirety, 
     This application claims the benefit of, and priority to, U.S. Provisional application No. 61/046,629, entitled “Use of flex cables for embedding webcam modules in electronics displays”, filed on Apr. 21, 2008, and is hereby incorporated herein in its entirety. 
     This application is related to co-pending application Ser. No. 11/478,898, filed on Jun. 30, 2006, entitled “Computer Monitor with Detachable Module”, which is owned by the assignee of the present invention, and which is hereby incorporated herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to embedded cameras, and more particularly, to thin webcams which do not compromise on image quality. 
     2. Description of the Related Art 
     It is becoming increasingly common for webcams (or other image capture devices) to be integrated into laptops or other electronic displays. Such integration of webcams into laptops etc. provides significant advantages (such as ease of portability, etc.). However, there are several issues associated with such integration as well. In particular, laptops are becoming increasingly thinner, and as a result, any webcam integrated into the laptop also needs to be very thin. However, a webcam that is very thin necessarily has a small depth of focus, thus compromising image quality. 
     Thus consumers are currently forced to choose between a larger webcam embedded in a device which is thicker and bulkier, and a thinner webcam embedded in an easier to handle device where the thinner webcam provides poorer image quality. Current webcam modules in displays (e.g., in laptop/notebook computers) have poor image quality. An indication of the extent to which current notebook webcam module image quality is suffering is offered by the fact that some original equipment manufacturers (OEMs) are retreating back from 1.3 Mega Pixel designs to VGA solutions, because the higher quality solutions are not viable in image capturing modules embedded in the increasingly popular thinner display panels. 
     In conventional webcam modules, an inherent tradeoff is necessary, because sleek notebook/display designs call for thin display bezels, while high quality webcam optics call for longer optics paths. As mentioned above, in several cases, current size restrictions for embedded webcam modules cause significant compromise in image quality. 
     There is thus a need for a webcam module which can fit into small spaces, but provide better image quality than anything currently available. Further, there is a need for a webcam module which has a form factor thin enough to be accommodated into a thin device, while still providing a sufficient focal length to provide good image quality. Further still, there is a need for an embedded webcam module which can easily switch from one position to another, where one position provides for a thin form factor, and the second position provides for improved image quality. 
     SUMMARY OF THE INVENTION 
     Various embodiments of the present invention provide for image capturing modules which can be embedded into thin displays (e.g., in laptop computers) and which provide for improved image quality. In accordance with several embodiments, a webcam module embedded in a display has multiple positions. A first position (or a “rest” or “park” position) is the position of the webcam module when it is not in use. In this first position of the webcam module, it is in its most compact configuration, and lends itself to integration into a very thin display. For instance, in one embodiment, this is the position of the webcam module when a laptop into which the webcam module is integrated, is closed. In other positions, the webcam module has a more expanded configuration, thus leading to better image quality. Such an expanded configuration leads, amongst other things, to a larger depth of focus. This can be achieved in some embodiments, for instance, by increasing the distance between a lens and a sensor in the webcam module. In other embodiments, there is no change in the relative position of the lens and the sensor—instead, the webcam module has a closed (or park) position in which the webcam is not used, and at least one open (or view) position. In such embodiments, the closed configuration allows for a more compact configuration of the webcam module integrated into the display, while the open configuration allows for good image quality. 
     Various different mechanisms can be used to facilitate the different positions of the webcam module. For instance, in one embodiment, the webcam module can be popped out by pushing upon it so that it protrudes from the display. In another embodiment, the webcam module is attached to the display from only one side (e.g., using a swivel joint), and can be pulled out from the plane of the display. In some such embodiments, the lens is at the other end of the webcam module. In some embodiments, the webcam module can also be rotated to change its orientation. In some such embodiments, the webcam module is detachable from the display, and can be replaced with other modules. In some such embodiments, an electrical connection (e.g., a USB or mini-USB connector) is also provided to connect the webcam module to the display. 
     In yet another embodiment, the webcam module is rotatable around an axis in the plane of the display In some such embodiments, the bottom portion of the webcam module in the park position becomes the front portion of the webcam module when it is in use. That is, in one embodiment, the webcam module is rotated 90 degrees around the axis, so as to make the lens face the image to be captured. Such embodiments utilize the fact that the vertical space available around a webcam module in a thin display is sometimes greater than the thickness of the display. 
     In still another embodiment, a stepped printed circuit board (PCB) is used. Such a stepped PCB has a thin portion and some thicker portions. The optical module is mounted upon the thin portion so as to accommodate the optical module, while the rest of the substrate is thicker to provide additional stability. Such embodiments allow for a more compact form factor for the webcam module, while still maintaining a high image quality. 
     The features and advantages described in this summary and the following detailed description are not all-inclusive, and particularly, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims hereof. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter, resort to the claims being necessary to determine such inventive subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention has other advantages and features which will be more readily apparent from the following detailed description of the invention and the appended claims, when taken in conjunction with the accompanying drawing, in which: 
         FIG. 1A , illustrates a laptop computer in accordance with an embodiment of the present invention, where the embedded webcam module protrudes beyond the display. 
         FIG. 1B  shows a closer view of the relief area on the bottom case of the laptop computer shown in  FIG. 1A , for accommodating the webcam module when the laptop is closed. 
         FIG. 1C  shows a closer view of the keyboard anon features on the bottom of the protruding webcam module shown in  FIG. 1A . 
         FIG. 2A  shows a display bezel of a laptop computer with a pop-out webcam module in accordance with an embodiment of the present invention. 
         FIG. 2B  shows a closer view of the keyboard illumination features on the bottom of the pop-up webcam module shown in  FIG. 2A . 
         FIG. 2C  shows features on the bottom portion of the laptop computer shown in  FIG. 2A , which interact with the pop-up webcam module. 
         FIG. 2D  shows the lens positioned proximate to the sensor in a closed position of the webcam module, in accordance with an embodiment of the present invention. 
         FIG. 2E  shows the lens positioned away from the sensor in an open position of the webcam module, in accordance with an embodiment of the present invention, 
         FIG. 3A  shows a conventional prior art webcam module. 
         FIG. 3B  shows an embedded webcam module in accordance with an embodiment of the present invention, showing both the parked and extended position. 
         FIG. 3C  shows a first view of an attachment mechanism for attaching a webcam module to a display in which it is embedded in accordance with an embodiment of the present invention. 
         FIG. 3D  shows a second view of an attachment mechanism for attaching a webcam module to a display in which it is embedded in accordance with an embodiment of the present invention. 
         FIG. 3E  shows a third view of an attachment mechanism for attaching a webcam module to a display in which it is embedded in accordance with an embodiment of the present invention. 
         FIG. 3F  shows an example of an attachment mechanism for attaching a webcam module to a display in Which it is embedded in accordance with an embodiment of the present invention. 
         FIG. 3G  shows a rotatable and/or detachable webcam module embedded in a display in accordance with an embodiment of the present invention. 
         FIG. 3H  shows the webcam module in  FIG. 3G  swinging out of the plane of the display, in accordance with an embodiment of the present invention. 
         FIG. 3I  is another view of the rotation of the webcam module in  FIG. 3G . 
         FIG. 3J  shows an electrical connection between a webcam module and a display in which it is embedded, in accordance with an embodiment of the present invention. 
         FIG. 4A  is a view of a laptop computer with an embedded webcam module in accordance with an embodiment of the present invention, where the webcam module needs to be turned around a rotation axis so as to be used. 
         FIG. 4B  illustrates the webcam module in  FIG. 4A  when not in use, 
         FIG. 4C  illustrates that the height of the webcam module is greater than its depth when not in use, in accordance with an embodiment of the present invention. 
         FIG. 4D  shows a webcam module with an elongated shape in a closed position, in accordance with an embodiment of the present invention. 
         FIG. 4E  illustrates an embodiment in accordance with the present invention where the rotation axis for the webcam module is vertically centered on the webcam module. 
         FIG. 4F  shows a front view of a webcam module shown in  FIG. 4E , rotated out so that the webcam can be used. 
         FIG. 4G  shows a side view of the display with the webcam module shown in  FIG. 4F . 
         FIG. 4H  shows an embodiment in accordance with the present invention where the rotation axis for the webcam module is not vertically centered on the webcam module. 
         FIG. 4I  shows a front view of a webcam module shown in  FIG. 4H , rotated out so that the webcam can be used. 
         FIG. 4J  shows a side view of the display with the webcam module shown in  FIG. 4I . 
         FIG. 5A  illustrates a conventional multi-layered PCB used in a webcam module. 
         FIG. 5B  is a closer view of the PCB shown in  FIG. 5A . 
         FIG. 5C  is a stepped PCB used in a webcam module in accordance with an embodiment of the present invention. 
         FIG. 5D  is a closer view of the PCB shown in  FIG. 5C . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The figures (or drawings) depict a preferred embodiment of the present invention for purposes of illustration only. It is noted that similar or like reference numbers in the figures may indicate similar or like functionality. One of skill in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods disclosed herein may he employed without departing from the principles of the invention(s) herein. It is to be noted that the following discussion relates to video, audio and/or still image data. For convenience, in some places “image” or other similar terms may be used in this application. Where applicable, these are to be construed as including any such data capturable by an image capture device. Further, it is to be noted that the terms “camera” and “webcam” are used various times in this discussion. Where applicable, these term includes various image capture devices such as, but not limited to, digital still cameras, video cameras, a combination of the two, webcams, wireless webcams, Personal Digital Assistants (PDAs), cell phones with image capturing abilities, portable media players, and so on. It is to be noted that various embodiments of the present invention could be used in the context of any such image capturing devices. 
     In addition, it is to be noted that various embodiments of the present invention can be used for such image capturing devices embedded (or embeddable) in any device, such as the display of a laptop/notebook, a display used with a desktop computer, a Personal Digital Assistants, a cell-phone, and so on. While most of the ensuing discussion mentions a webcam embedded in the bezel of a display of a laptop, the various embodiments described herein are not limited to such implementations. It is also to be noted that a webcam in accordance with embodiments of the present invention may be embedded in the display housing or display itself, rather than in the bezel of the display. The various embodiments of the present invention relate to ways to package webcam modules in a small space while still providing for the key dimensions that drive optics performance of the webcam. A webcam module in accordance with the present invention includes a housing, sensor, and a lens which captures the light and delivers it onto the sensor. Webcam modules in accordance with various embodiments of the present invention increase quality of the captured images. As an example, embodiments in accordance with this invention allow for high performance and longer optics while also allowing for thin notebook display bezels. In various different ways, a longer optics path (also called the “Z distance” or the “Z height”) is provided, thus leading to better image quality, while still allowing for the embedding device (e.g., laptop) to maintain a thin appearance. An increased Z distance or Z height allows for the light rays received by the sensor in the webcam module to be more parallel, since they don&#39;t need to bend a lot as they would in a small Z distance. In one embodiment, this is done by increasing the distance between the lens and the sensor. In one embodiment, this is done by having a webcam with a longer optical length embedded in a display in a storage position, which can then be opened up to a viewing position. In one embodiment, such a webcam has a longer lens, which again can be accommodated in a storage position in the display. 
     Locally Raised Areas at Webcam Module that Provide Increased Z Height While Maintaining Overall Panel Thinness 
     In some embodiments, the webcam module is raised, or is thicker than the rest of the panel in which it is embedded. 
     In one embodiment, the extra thickness of the webcam module is accommodated into the laptop in some way.  FIG. 1A  illustrates a laptop computer in accordance with an embodiment of the present invention. The laptop computer has a lower portion  110  (comprised mainly of the keyboard etc.) and an upper portion  120  (comprised mainly of the display  122 ). The display  122  is surrounded by a thin bezel  124 . A webcam module is embedded in the bezel  124 . The lens  126  of the webcam module is visible. Additionally, two lights  128  are also visible underneath the webcam module. 
     As can be seen from  FIG. 1A , the webcam module is thicker than the rest of the bezel  124 . The relatively larger thickness of the webcam module provides increased Z height for the optics in the webcam. With this design, the webcam module protrudes from the front of the notebook&#39;s thin display bezel  124 . However, this protruding webcam module is accommodated, in one embodiment, by a recessed portion/relief  114  in front of the touchpad where the webcam is located when the notebook display is closed. The relief area  114  near the touchpad also provides the benefit of improved touch-feel for the left/right input buttons. That is, it is easier to operate these buttons in a no-look situation. A closer view of the relief area  114  can be seen in  FIG. 1B . 
     In one embodiment, two lights (e.g., LEDs)  128 , are hidden under the webcam module protrusion provide for keyboard illumination. A closer view of these lights can be seen in  FIG. 1C . 
     In some embodiments, the increased thickness of the webcam module is only temporary—such as when the webcam is operational.  FIG. 2A  illustrates one such embodiment of the present invention, which shows a display bezel  124  with a pop-out webcam module  220 . In one embodiment, when the webcam  220  is not in use and/or when the laptop case is closed, the webcam  220  is pushed in and thus does not have additional thickness. When the webcam  220  is to be used, it is popped out, and thus provides for a longer optical path. 
     In one embodiment, with this design, the webcam optics module is broken into two different sub-assemblies. One sub-assembly is mounted to the display bezel, the other to the pop out module. In one embodiment, the optics path is complete and correct when the webcam is placed in its outermost position—this brings the outermost lens elements into their correct position. In one embodiment, the webcam module  220  is spring loaded with a “push-push” latch mechanism. Pushing on the retracted module will cause it to extend. Once extended, the module is closed by pushing it into the display until the spring is latched into place. In one embodiment, as discussed above, keyboard illumination features  128  are placed on the underside of the webcam module  220 . This can be seen in  FIG. 2B . 
     In one embodiment, which is shown in  FIG. 2C , there are two small bump features  210  on either side of the notebook touchpad. These features push the webcam module  220  into the closed position if the notebook display is closed while the module  220  is extended. In one embodiment, the design of these bumps  210  is such that they make the module  220  partially closed, but not fully latched into the retracted position. As a result, the spring-loaded module will open automatically once the display is opened. 
     In one embodiment, a longer optical path is created by increasing the distance between the lens  126  and the sensor  228 . A certain distance between lens and sensor (called “back focal length”) exists for each webcam module, where the resultant image is properly focused. In the embodiment shown in  FIG. 2D , the lens  126  is physically touching (or almost touching) the top of the sensor  228  in the closed position—and the resulting image is out of focus. When the module is popped-out/moved to the second position, the sensor  228  and PCB  225  remain fixed (no movement from the closed position), while the lens  126  moves with the front module housing. This movement of the lens increases the distance between lens  126  and sensor  228  such that the correct back focal length is achieved and the resultant image is in focus. This can be seen in  FIGS. 2D and 2E . 
     Swing-Out Webcam Module with Lens Positioned Along the Long Axis and Potential Connection Via Standard USB Plug 
     As mentioned above, laptop computers and their embedded webcams are designed to be very thin. In conventional embedded webcams, the Z axis for the camera module lens is restricted by the shape and size requirements of the embedding device. The resulting lens assembly is thus restricted to fewer lens elements and also provides less than the ideal amount of light to the image sensor (which may be a CMOS sensor). 
     In accordance with some embodiments of the present invention, these optical problems are addressed so as to significantly enhance image quality for embedded webcams, by increasing the possible length of the optical path, the number and size of optical elements (e.g., lenses etc.) can be increased, and so on. 
       FIG. 3A  shows a conventional embedded webcam module. It can be seen that the z-distance here is limited by the thickness of the display in which the webcam module is embedded. It can be seen in the embodiments shown in  FIGS. 3B-3J , that the z-axis length can be significantly longer than in conventional embedded webcams, and thus an optimal z-axis length can easily be implemented.  FIG. 3B  shows an embedded webcam module in accordance with an embodiment of the present invention, where the webcam module has a park position (when it is not in use) and a view position (when it can be used). It can be seen that a webcam module  310  is embedded in the bezel  124  of the display. As can be seen from  FIG. 3B , the park position of the webcam module  310  is when it is flush with the bezel  124 , while the view position is when the webcam  310  is pulled out front the plane of the display. In one embodiment, the view position is when the webcam module  310  is pulled out to a position approximately perpendicular to the plane of bezel  124 . 
       FIGS. 3C-3E  further show an example of one way in which the embodiments shown in  FIGS. 3A and 3B  can be implemented. In one embodiment, a swivel joint  312  is used to attach the webcam module  310  to the bezel  124 . The webcam  310  can be used at several viewing angles in such an embodiment. In one embodiment, a ball joint is used to attached the webcam module to the bezel  124 . 
       FIGS. 3F -3J  show other examples of ways in which the embodiments shown in  FIGS. 3A and 3B  can be implemented. It is to be noted that several other types of joints/connections could also be used. In many of these embodiments, the webcam module is detachable, as can be seen in  FIG. 3G . In such embodiments, the webcam module can be replaced by another webcam module, thus allowing replacement/upgrade to the module. In one embodiment, the webcam module is replaced by another module altogether (for instance, a module with a speaker and/or microphone, a module with lights, etc.). Such detachable modules are described in greater detail in co-pending application Ser. No. 11/478,898, filed on Jun. 30, 2006, entitled “Computer Monitor with Detachable Module”, which is owned by the assignee of the present invention. 
     It can be seen from several of these figures (e.g.,  FIG. 3H ) that in one embodiment, the lens  126  is at one end of the webcam module  310 . Thus the lens  126  is protected when in the park position. Additionally, such an embedded webcam is secure for shipment. Also, when in the park position, a privacy shade is automatically implemented—image data is not captured and/or transmitted when the webcam  310  is in a park position. 
       FIG. 3I  shows that in one embodiment, the camera  310  can be rotated to switch lens orientations—for example, between portrait and landscape. In one embodiment, other orientations (e.g., diagonal) are also implemented. In one embodiment, such a rotation could be manual. In one embodiment, such a rotation could be automatic (e.g., based upon the image data being captured). 
       FIG. 3J  shows that in one embodiment, the camera module  310  attaches to the rotating arm via a connector  340 . It can be seen that in one embodiment, an electrical connector is combined with/is part of the mechanical connector. For instance, a mini-USB cable is part of connector  340 . It is to be noted that the mechanical and/or electrical connectors are not limited to the ones described above, but that the examples above are merely illustrative. 
     Rotating Webcam Module with Oblong Shape that Provides thin Profile when Closed, Increased Z Height when Open 
     In accordance with an embodiment of the present invention, the integrated camera  410  can be embedded into the display bezel  124  on its side. In other words, the z-axis of the lens lies along the height (rather than the width) of the camera  410 , and the camera  410  needs to be turned around a rotation axis so as to use it. Again, as above, the z-axis length of the camera  410  is increased significantly without increasing the thickness of the display in which it is embedded. Such embodiments are shown in  FIGS. 4A-4J .  FIG. 4A  shows the camera  410  in a working position.  FIG. 4B  and  FIG. 4C  show that when the camera  410  is not being used, the height of the lens is greater than its width. 
       FIG. 4D  shows a webcam  410  with an elongated shape—the module  410  here is in the closed position.  FIG. 4E  illustrates an embodiment where the rotation axis  420   a  for the webcam module  410  is vertically centered on the module  410 .  FIG. 4F  shows a front view of the module  410  rotated out so that the webcam can be used—the lens  126  is on the bottom surface of the camera module  410  when it is in the closed position. Such a placement of the lens  126  protects the lens when the camera module  410  is in the closed position. However, it is to be noted that the lens  126  can be placed elsewhere in accordance with embodiments of the present invention (e.g., at the top surface of the module  410 ).  FIG. 4G  shows a side view of the display with the module  410  rotated out. It can be seen that there is a protrusion on the backside of the display in which the webcam  410  is embedded, because the rotation axis is centered on the module  410 . 
       FIG. 4H  shows an embodiment where the rotation axis  420   b  is not centered on the webcam module  410 . Instead, the rotation axis  420   b  for the webcam module  410  is located higher than the center, so that the module  410  does not protrude from the rear of the display when rotated, as can be seen in  FIG. 4J .  FIG. 4I  shows a front view of the module  410  rotated out so that the webcam can be used—the lens  126  is on the bottom surface of the module  410  when it is in the closed position. In one embodiment, the rotation is located lower than the center, such that the open module does not protrude from the front of the display. In this embodiment, the notebook display may be closed without having to rotate the webcam module to the closed position. 
     In various embodiments it is possible for the webcam module to rotate both clockwise and counterclockwise—allowing the lens to point to the from or rear of the notebook display. 
     Webcam Module on Stepped PCB Substrate—Thick PCB Area Used for SMT Assembly, Thin Area Used for Sensor/Optics 
     In conventional PCB fabrication, uniform layers of substrate material are laminated together to form a multi-layer printed circuit board. An example of a webcam module with a conventional 4 layer PCB is shown in  FIG. 5A . In this example, the board is a laminate of 4 layers of PCB material, each layer being 0.2 mm thick. A cross section of this module is shown in  FIG. 5B . If the thickness of the PCB is too small, the structural rigidity of the webcam module is compromised. However, having a thick PCB under the optics module leads to increased thickness of the webcam module, which is often undesirable and/or unacceptable for thinner and sleeker displays. 
     As discussed above, for webcam module designs, total module thickness is a key parameter to be minimized. In order to reduce the total height of a webcam module  500 , in accordance with some embodiments of the present invention, a PCB  520  is built that contains multiple, thin layers  525  of PCB material under the optics module  510  (including, for example, the sensor  228 , lens  126 , and lens holder  522 ) as well as additional, thicker layers of PCB material on either side of the optics module.  FIG. 5C  shows an example of such a PCB, in accordance with some embodiments of the present invention. In the embodiment shown in  FIG. 5C , there are 4 layers of very thin PCB material under the optics module  510 , and 2 additional layers  530  of thicker PCB material on either side. This can be more clearly seen in  FIG. 5 , which shows the cross-section of the substrate shown in  FIG. 5C . 
     In the specific example discussed above with reference to  FIGS. 5A-5D , the optics module  510  gets an extra 0.60 mm. (The total PCB thickness is 0.80 mm, but it is only 0.20 mm in the area of the optics module.) This construction still provides a rigid PCB (since the thicker PCB layers  530  will provide good structural rigidity), while also improving image quality by increasing the space available for the optics module  510 , thus allowing for an increased z-distance. In an alternate embodiment, the total height of the webcam module  500  is reduced, thus lending itself to embedding in a thinner display/laptop. 
     An added benefit is provided by the fact that the thin PCB layers  525  in the above example will have low rigidity. Thus, these thin layers  525  will provide vibration isolation that will protect the delicate die on the sensor in the optics module  510 . Vibration will propagate efficiently across the thick, rigid PCB layers  530 , but will be significantly dampened across the thin, flexible PCB layers  525 . 
     In one embodiment, an additional stiffener piece (e.g. 0.10 mm thick steel plate) is added to the bottom of the PCB  520  to increase rigidity of the total system. In one embodiment, this stiffener is made of metal, and provides the additional benefits of increased heat dissipation and reduced electromagnetic emissions. In this case, the vibration dampening effect of the thin PCB layers will be reduced. 
     While particular embodiments and applications of the present invention have been illustrated and described, it is to be understood that the invention is not limited to the precise construction and components disclosed herein. For example, as mentioned earlier, in any of the above embodiments, the embedded webcam module may be detachable from the device in which it is embedded. As another example, different types of connectors, materials, etc. can be used. As still another example, the various embodiments discussed above arc applicable not only to laptops, but also to various other devices in which cameras may be embedded, such as cell phones, PDA&#39;s, media players, etc. Various other modifications, changes, and variations which will be apparent to those skilled in the art may be made in the arrangement, operation and details of the method and apparatus of the present invention disclosed herein, without departing from the spirit and scope of the invention as defined in the following claims.