Abstract:
A module placement device and method enable the precision mating of a module to a substrate. The device and method can be effectively used, for example, to mate a light source such as an LED module to the back side of an automotive mirror having portions that permit light to pass therethrough.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to the field of precision automated manufacturing. More particularly, the present invention relates to a device and method for automatically placing a module on the underside of an object using optical cues to align the module to the object. 
         [0002]    BACKGROUND AND SUMMARY 
         [0003]    Modern automotive mirrors are being called upon to provide more than just a reflective surface for viewing next to or behind the vehicle. In many cases it is desirable to provide the driver with information using the mirror surface but enable the complete mirror surface to be reflective when the information is not being provided. For example, a rear view mirror might include icons indicative of direction, vehicle functions such as telephone use, and other information and a side view mirror may warn a driver that the turn signal is activated or the side view mirror may be connected to a blind spot detection system so that the driver can be warned about a vehicle in the blind spot. In order to achieve a usable mirror surface when the icons are not activated, a number of techniques have been developed. One common technique is to use fine ablations of the reflective surface so that light can pass therethrough but a substantial portion of the reflective surface remains intact. When the light behind the mirror for the icon is activated it passes through the ablation and can be seen and when the light is not activated the mirror effect remains substantially intact. 
         [0004]    Certain automotive manufactures desire highly detailed icons to appear in the mirrors, with a high degree of light, and minimal affect on normal mirror operation. To achieve these requirements, mirror manufacturers have found it necessary to precisely align highly-engineered reflectors and light sources (these highly-engineered reflectors and light sources are referred to herein as “modules”) behind finely ablated mirrors. Traditionally, these modules have been positioned against the mirror backs by hand but in the manufacturing process this can lead to an unacceptably high level of rejected parts due to failure to meet performance objectives. As such, there is a need for a high-precision device and method to mate a module to a mirror substrate. 
         [0005]    The present invention relates to a device and method to precisely mate a highly-engineered light source and reflector module to the rear of a mirror substrate. The device and method include the ability to place the module and substrate into fixtures, reposition at least one of the module and the substrate, and then press the two together so that the module adheres to the rear of the substrate. The device and method could have other applications where similar performance characteristics are desirable. 
         [0006]    It will be understood by those skilled in the art that one or more aspects of this invention can meet certain objectives, while one or more other aspects can lead to certain other objectives. Other objects, features, benefits and advantages of the present invention will be apparent in this summary and descriptions of the disclosed embodiment, and will be readily apparent to those skilled in the art. Such objects, features, benefits and advantages will be apparent from the above as taken in conjunction with the accompanying figures and all reasonable inferences to be drawn therefrom. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a perspective view of one embodiment of a module placement device in accordance with the invention; 
           [0008]      FIG. 2  is another perspective view of the module placement device of  FIG. 1  with the protective housing removed; 
           [0009]      FIG. 3  is a detail view of the module placement device of  FIG. 1  showing the vertical movement of the substrate clamp arm; 
           [0010]      FIG. 4  is a flow chart depicting an operation sequence of a device and method in accordance with one embodiment of the invention; 
           [0011]      FIG. 5  is another detail view of the module placement device of  FIG. 1  showing the initial horizontal movement of the module fixture; 
           [0012]      FIG. 6  is another detail view of the module placement device of  FIG. 1  showing the calibrating vertical movement of the module fixture; 
           [0013]      FIG. 7  is another detail view of the module placement device of  FIG. 1  showing the lowering of the module fixture before placement of the module; 
           [0014]      FIG. 8  is another detail view of the module placement device of  FIG. 1  showing the movement of the module fixture into placement position; 
           [0015]      FIGS. 9-11  are side section views of the module placement device of  FIG. 1  taken generally along the line  8 - 8  in  FIG. 7  showing placement of the module onto the substrate; 
           [0016]      FIG. 12  is another detail view of the module placement device of  FIG. 1  showing removal of the substrate with the module attached; and 
           [0017]      FIG. 13  is another detail view of the module placement device of  FIG. 1  showing the degrees of movement of the module fixture. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]      FIGS. 1-3  and  5 - 13  show one embodiment of a module placement device  100  in accordance with the invention. The module placement device  100  stands on a base  102  and has a protective housing  104 . In the embodiment shown, the protective housing  104  includes safety provisions to prevent unintended operation of the module placement device  100  while an operator&#39;s hand is near the device. Such safety provisions may include light curtains, emergency stop switches, two hand controls, mechanical guards, or any other suitable means without departing from the invention. Near the module placement device  100  is an operator interface  106  that allows an operator to configure and monitor operation of the module placement device. In the embodiment shown, the operator interface  106  is a touch screen attached to the protective housing  104 , but any other user interface may be used without departing from the invention. Alternatively, the user interface may include but are not limited to a computer with keyboard and mouse, or may be replaced by a programmable logic controller or equivalent. 
         [0019]    Turning now to  FIG. 2 , a detail view of the module placement device  100  is shown. The module placement device includes a module fixture  110 , and a substrate fixture  112 . In the embodiment shown, the substrate fixture  112  is for the placement of a blind spot monitor alert light on a side view car mirror, but any suitable substrate may be used without departing from the invention. The module fixture  110  is attached to a plurality of actuators and motors that move the module fixture during the module placement process. The substrate fixture  112 , on the other hand, remains stationary throughout the module placement process. Of course, the module fixture  110  could remain stationary while the substrate fixture  112  moves without departing from the invention. As shown in greater detail in  FIG. 3 , a substrate clamp arm  114  is located near the substrate fixture  112  that secures a substrate  116  to the substrate fixture during the module placement process. A camera  118  is positioned above the module fixture  110 . 
         [0020]    The operator interface  106 , module fixture  110 , and camera  118  are connected to a controller that controls the operation of the module placement device  100 . In the embodiment shown, the controller includes a processor, memory, and program that moves the module fixture  110  based on images captured by the camera  118 . A program is loaded into the controller based on the geometry of the substrate and the module being placed. 
         [0021]    Turning now to  FIGS. 4-11 , one cycle of the operation of the module placement device  100  is shown.  FIG. 4  is a flowchart showing a typical module placement cycle.  FIGS. 5-11  show the module placement device  100  in various stages of the module placement cycle. The module placement device  100  works by visually identifying landmarks on the substrate  116  and a module  118  to automatically and precisely align the substrate and module together. In the embodiment shown, the module  118  has an adhesive face that permanently bonds to the substrate  116  when the module is pressed onto it. Of course, the module  118  could be non-adhesive, with adhesive on the substrate  116  without departing from the invention. Just prior to the start of an operation cycle of the module placement device  100 , an operator places a module  118  in the module fixture  110 . Next, the operator starts the module placement device  100  by pressing a button on the operator interface  106  or by any other suitable means.  FIG. 5  shows the movement of the module fixture  110  into a position beneath the camera  118 . Next, as shown in  FIG. 6 , the module fixture  110  raises to the height of the substrate  116 . The camera  118  is focused on both the substrate  116  and the module  118  and the controller, based on the image captured by the camera when the module fixture is raised to the height of the substrate  116 , calculates the position of the module relative to the substrate. In the embodiment shown, the controller recognizes landmarks on the module  118  and the substrate  116  and uses software to calculate how to align them to each other. Multiple cameras could be used without departing from the invention. 
         [0022]    Turning now to  FIG. 7 , the controller moves the module fixture  110  back to a descended position so it can move beneath the substrate. At the same time, the controller moves the module fixture  110  based on the calculation described above so that the module  118  is properly aligned with the substrate  116 .  FIG. 8  shows the movement of the module fixture  110  into position beneath the substrate  116 . 
         [0023]      FIGS. 9-11  show how the module  118  is placed on the substrate  116 . In  FIG. 9 , the module fixture  110  is positioned beneath the substrate and in position to be affixed to the substrate.  FIG. 10  shows the module fixture  110  raised so that the module  118  is pressed onto the substrate  116 .  FIG. 11  shows the module fixture  110  descending back to its position in  FIG. 9 , with the module  118  affixed to the substrate  116 . After the module  118  is affixed to the substrate  116 , the substrate clamp arm  114  raises and swings away, allowing the operator to remove the now completed part  120  ( FIG. 12 ). 
         [0024]      FIG. 13  shows the module fixture  110  in greater detail. In the embodiment shown, the module fixture is movable in four directions. The module fixture  110  is movable in the X, Y, and Z axes, as well as a rotational axis around the Z axis. Providing four axes of available movement allows the module  118  to be precisely placed on the substrate  116 . In the embodiment shown, three stepper motors  122  and a linear actuator control the movement of the module fixture  110 . The stepper motors  122  control X, Y, and rotational position, and the linear actuator controls the position of the module fixture  110  along the Z axis. Using stepper motors  122  allows precision control of the position of the module fixture  110 , but any other suitable means may be used without departing from the invention. 
         [0025]    Although the invention has been herein described in what is perceived to be the most practical and preferred embodiments, it is to be understood that the invention is not intended to be limited to the specific embodiments set forth above. Rather, it is recognized that modifications may be made by one of skill in the art of the invention without departing from the spirit or intent of the invention and, therefore, the invention is to be taken as including all reasonable equivalents to the subject matter of the appended claims and the description of the invention herein.