Abstract:
According to the invention, an electronic module tester for engaging a camera module is disclosed. The electronic module tester includes a camera tester body, an engagement ring, and a camera back support. The engagement ring engages a lens holder of the camera module, where the engagement ring comprises an engagement surface, an outer circumference and an inner circumference. The engagement surface rotates and is not keyed for any key on the lens holder. The camera back support engages a back of the camera module, where the back is on the opposite side of camera module as the lens holder. The engagement ring and the camera back support are separated, but biased together to engage the camera module.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. § 119 and/or 120 to U.S. Provisional Application Ser. No. 60/519,597 filed on Nov. 12, 2003. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     This disclosure relates in general to electronic camera module testing and, more specifically, but not by way of limitation, to engagement of the camera to the test fixture. 
     Camera modules are tested by adjusting their focus by adjusting a lens holder which rotates in a tube or barrel. As the lens holder rotates, the lens moves with respect to the imaging array. The lens holder typically has notches, bumps or indentations that can be mated to a custom tool such that a test fixture can rotate the lens holder while the camera module is positioned to focus on a test pattern. For example, if the lens holder had four circular indentations, the customized tool would have four bumps to mate with the circular indentations. The lens holders are manufactured by various third parties and have a variety of different grips on the lens holder that would require a variety of mating tools. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure is described in conjunction with the appended figures: 
         FIG. 1  is a diagram of an embodiment of a camera module; 
         FIG. 2  is a diagram of an embodiment of a electronic imager tester; 
         FIG. 3  is a side plan view of an embodiment of a portion of the electronic imager tester showing engagement of the camera module; 
         FIGS. 4A and 4B  are top plan views of embodiment of an engagement ring; 
         FIG. 5  is a top plan view of an embodiment of a portion of the electronic imager tester showing engagement of the camera module; 
         FIG. 6  is a diagram of an embodiment of a portion of the electronic imager tester showing where the camera module is loaded; 
         FIG. 7  is a diagram of an embodiment of a portion of the electronic imager tester showing the camera module biased in place; and 
         FIG. 8  is a flow diagram of an embodiment of a process for producing a camera with the electronic imager tester. 
     
    
    
     In the appended figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The ensuing description provides preferred exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the invention. Rather, the ensuing description of the preferred exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing a preferred exemplary embodiment of the invention. It being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention as set forth in the appended claims. 
     Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments maybe practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, structures and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments. 
     Also, it is noted that the embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed, but could have additional steps not included in the figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function. 
     Referring first to  FIG. 1 , a diagram of an embodiment of a camera module  100  is shown. Mounted on a printed circuit board  132  of the camera module  100  are a holder assembly  124 , a connector  120 , a miscellaneous other components. The holder assembly  124  includes a holder tube  128 , a lens holder  108 , and a lens  116 . The lens holder  108  rotates with respect to the holder tube  128 . The rotation moves the lens  116  closer or further from a imager to focus the imager. The lens holder has orientation holes or indentations  104  that can be mated to a tool that can be used to rotated to focus the imager. Different camera modules have different orientation holes  104  or other keying such that a custom tool for each configuration may be required. 
     With reference to  FIG. 2 , a diagram of an embodiment of a electronic imager tester  200  is shown. A slide target assembly  204  hold slides that can be moved in front of the camera module  100 . The slides provide test scenes to focus upon when the lens  116  is being adjusted. A slide frame handle  208  is used to move slides in front of the camera module  100 . A camera module stage  212  is where the camera module  100  is loaded during the test process. Camera modules  100  are inserted into the stage  212  one after another to adjust for proper focus. Once mounted in the stage  212 , the camera module  100  can be moved with three degrees of freedom (i.e., yaw, roll and pitch). 
     Referring next to  FIG. 3 , a side plan view of an embodiment of a portion of the electronic imager tester  200  that shows engagement of the camera module  100  is shown. An electrical connector  308  electrically couples the camera module to the imager tester  200 . The connector  308  allows operating the camera module and reading the resulting images such that the operator and/or test software can test the camera module  100 . 
     The camera module  100  is pinched between the lens holder  108  and the back of the printed circuit board  132 , by an engagement ring  312  and a back support  318 . A cone  304  made of aluminum, plastic or rubber has a shape that accommodates the field of view for the camera module  100  and is attached to the engagement ring  312  made of rubber or otherwise pliable in this embodiment. The attachment between the cone  304  and ring  312  can be permanent in one embodiment because the ring  312  does not have to be switched for different keying of the lens holder  108  for the various camera modules  100  that might be tested. 
     The cone  304  and engagement ring  312  are attached to a manual or motorized mechanism that causes rotation. When the engagement ring  312  is in contact with the lens holder  108  such that they are biased together, the rotation is transferred to the lens holder  108  to focus the lens  116 . The equipment operator controls the rotation while viewing the output of the imager that is focused on the slide image. In some embodiments, the focusing is automated to be done without operator control. 
     The back of the printed circuit board  132  is in contact with the back support  318 . The back support is supplied with a biasing or spring force  322 . The biasing force  322  allows the engagement ring to friction grip the lens holder. Different engagement ring material and holder assembly  124  configurations may use different biasing force  322 . By using a friction grip, any type of camera module  100  can be used without regard for engaging any keying (e.g., orientation holes) for a particular camera module  100 . The engagement ring  312  and cone  304  are sized to accommodate a variety of lens diameters, lens holder diameters, and field of views. 
     In this embodiment, the biasing force  322  can be adjusted. With too much biasing force  322  the threaded engagement between the lens holder  108  and the tube holder  128  can cause the threaded engagement to bind or seize. Too little biasing force  322  and the engagement ring  312  may not friction grip the lens holder  108  or the whole camera module  100  might rotate with the engagement ring  312 . Periodic calibration for a production run allows engaging many camera modules  100  without intervening adjustments. 
     In this embodiment, the biasing force  322  is applied by the back support  318  with the engagement ring  312  being fixed. Other embodiments could have the back support  318  being fixed with the engagement ring  312  and cone  304  being biased toward the back support  318 . 
     With reference to  FIG. 4A , a top plan view of an embodiment of an engagement ring  312 - 1  is shown. A surface  404  engages the lens holder. Notably, the surface  404  is not keyed for a particular lens holder  108  in this embodiment. The surface  404  could have texturing to enhance the friction grip ability. In this embodiment, the surface  404  is rubber, but could be cork, a polymer, or other material in other embodiments. 
     The engagement ring  312  is an annular ring shape in this embodiment. There is an internal circumference  408  that defines an aperture  412 . The aperture  412  is sized to not obscure the field of view of the lens  116  and to accommodate some alignment tolerance between the engagement ring  312  and the camera module  100 . Larger imagers could have larger lenses that require a larger aperture  412 . An outer circumference  414  of the engagement ring  312  may or may not be larger than the distal circumference of the lens holder  108  in various embodiments. In one embodiment, the internal circumference  408  has a diameter of 4 mm or more, the outer circumference  414  has a diameter of 8 mm or more and a thickness of 1 mm or more. 
     With reference to  FIG. 4B , a top plan view of another embodiment of the engagement ring  312 - 2  is shown. In this embodiment, there are four pads that engage the lens holder  108  without obscuring the lens  116 . Any arrangement of engagement surface(s)  404  could be used in various embodiments to establish a friction grip of the lens holder  108 . In one embodiment, the engagement surface(s)  404  is keyed for a first set of orientation holes  104 , but could be used with other camera modules  100  with different keying. The camera modules  100  with keying that doesn&#39;t match the engagement surface(s)  404  would rely upon a friction grip. 
     Referring next to  FIG. 5 , a top plan view of an embodiment of a portion of the electronic imager tester  200  is illustrated that shows engagement of the camera module  100 . The camera module  100  is inserted before an support arm  504  is pulled away from a plane defined by the back of the camera module while rotating the support arm  504  to engage the back support  318  to the camera module  100 . The rotation of the support arm  504  is limited by a stopper pin  508 . 
     With reference to  FIG. 6 , a diagram of an embodiment of a portion of the electronic imager tester  200  is shown that illustrates where the camera module  100  is loaded. The camera module  100  is inserted into the staging area  212  such that the lens holder  108  engages the engagement ring  312 . A guide tube  616  can be sized for the holder tube  128  to position the lens  116  with respect to the aperture  412  of the engagement ring  312 . For holder tubes  128  of different diameter, the guide tube  616  could be sized accordingly. 
     In some embodiments, the guide tube  616  may be oversized to accommodate a variety of diameters for the holder tubes  128 . If the aperture  412  obscures the image, the operator can reposition the camera module  100  until the field of view is clear. 
     This embodiment has a fixed connector  308  that engages the camera module  100  to provide electrical connectivity. In some embodiments, the connector  308  could be on a flexible connector to allow different placement of the mating connector  120  on the camera module  100 . Further, some embodiments could have adapter cables to accommodate different connectors  120  on the camera module  100 . 
     The support arm  504  rotates counter clockwise to engage the camera module  100 . The biasing member  604  is located near the axis of rotation of the support arm  504 . In this embodiment, the biasing member  604  is a elastic material such as rubber. 
     A spring force adjuster  608  can be rotated to increase or decrease the compression of the biasing member  604  to increase or decrease the spring force  322  of the back support  318 . Once adjusted, the compression of the biasing member  604  does not change with normal operation of the support arm  504 . Other embodiments could use a coil spring, a leaf spring, a motorized engagement force, a mechanical engagement force, or other means to engage the camera module  100 . Although this embodiment has the spring mechanism at the axis of rotation of the support arm  504 , other embodiments could locate the spring mechanism at the distal part of the support arm  504 . 
     Referring next to  FIG. 7 , a diagram of an embodiment of a portion of the electronic imager tester  200  is depicted that shows the camera module  100  biased in place. The support arm  504  has been rotated to the stopper pin  508 . The operator fights the spring force  322  until the arm  504  hits the stopper  508  and then gently releases the arm  504  to engage the camera module  100 . 
     With reference to  FIG. 8 , a flow diagram of an embodiment of a process  800  for producing a camera with the electronic imager tester  200  is shown. The camera module could be embedded in a phone, web cam, surveillance camera, video camera, still camera or any other electronic device. The depicted portion of the process begins in step  804  where the biasing force  322  is periodically calibrated during a production run. A force meter can be applied to the back support  318  while the spring force adjuster  608  is manually adjusted. Some embodiments have an automated biasing force  322  that presses down on the camera module  100  until a predetermined force is measured. 
     In step  808 , the imaging array and support electronics are produced or gathered. The imaging array or imager could be on a single chip with some support electronics or there could be multiple chips. The camera module  100  is assembled in step  812  with the circuit card  132 , housing  124 , etc. 
     During engineering or production testing, the camera module  100  is loaded into the imager tester  200  by orienting the module  100  and inserting the holder tube  128  into the guide tube  616 . This embodiment adjusts the focus at the module stage, but other embodiments could adjust the focus after the camera module  100  is integrated into a larger assembly. In step  820 , the support arm  504  is rotated and released to engage the back support  318  against the camera module  100 . 
     A manual knob is coupled to the cone  304  to rotate the lens holder  108  while the operator views a readout or display to adjust focus of the camera module  100  in step  824 . Other embodiments could have a motorized mechanism to rotate the cone  304 . Some embodiments could use machine vision to determine when the lens  116  is focused. Any additional calibration is performed in step  828 . The calibrated module  100  is ready for embedding in a larger assembly in step  832 . 
     While the principles of the disclosure have been described above in connection with specific apparatuses and methods, it is to be clearly understood that this description is made only by way of example and not as limitation on the scope of the invention.