Abstract:
Apparatus and method is provided for using low cost, passive RF sensor technology such as RFID tags, to determine whether containers or other objects are in a right-side-up orientation. A useful embodiment of the invention is directed to sensor apparatus for use in detecting an improper orientation of a conventional box or container with respect to a substantially horizontal surface. The apparatus includes a structure having two sides formed of plastic in spaced apart relationship, to define an enclosed space within the structure. Selected shielding material attached to the structure shields a specified region of the enclosed space against RF signals, the shielded region being located in the lowest portion of the enclosed space when the structure is in a reference orientation with respect to the horizontal surface. An RFID tag embedded in a disk is positioned in the enclosed space, the disk being sized to move freely within the space. A guide element guides the disk in moving between the shielded region and an unshielded region, when the structure is correspondingly moved between its reference orientation and an improper orientation corresponding to an improper orientation of the container. This allows a signal to be received from the RFID tag when it becomes unshielded, to indicate improper container orientation.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The invention disclosed and claimed herein generally pertains to an apparatus and method that uses a passive or active sensor, such as a low-cost RF Identification (RFID) tag, to determine that a specified object is not in a correct or proper orientation. More particularly, the invention pertains to apparatus of the above type for use with shipping containers and the like, to readily determine that a container is not in a “right-side-up” orientation. It is anticipated that embodiments of the invention will be useful for detecting improper container orientation in warehouses or other environments in which it is difficult or time consuming to visually inspect the orientations of individual containers.  
         [0003]     2. Description of the Related Art  
         [0004]     As is well known, conventional cartons or containers, of a type widely used to pack, ship and store products of many different kinds, typically have six rectangular sides. Each of the sides is in substantially orthogonal relationship with every other side with which it shares a common edge. As is further well known, it is very common to designate one of the sides of such containers as the top side, and the opposing side as the bottom side. Moreover, it may be important to maintain the container in a “right-side-up” orientation. In such orientation, the top side of the container is directed upward, and the bottom side is conversely directed downward. This may be necessary to prevent damage or to ensure safety. For example, a container may be used to hold comparatively fragile products, such as computer equipment or other electronic components. To protect the product if the container is unintentionally dropped, substantial cushioning material could be placed between the product and the bottom side of the container. However, if the container is not kept in a right-side-up orientation, the benefit of the cushioning placed along its bottom side would be substantially reduced.  
         [0005]     Notwithstanding the importance of proper orientation, it may frequently be quite difficult to determine whether a box or container, as it is being stored or shipped, is in fact correctly oriented. This situation is often encountered in high volume package environments, such as warehouses, manufacturing facilities and transport vehicles. In these types of environments, it may be difficult or impossible to visually inspect every side of a container, or to detect orientation markings printed thereon. Accordingly, it would be beneficial to provide container handlers and others with improved non-visual means for readily detecting improper orientation of containers or boxes.  
       BRIEF SUMMARY OF THE INVENTION  
       [0006]     The invention provides an apparatus and method for using low cost, RF sensor technology, such as RFID tags or devices, to determine whether or not containers or other objects are in a right-side-up orientation. In a useful embodiment, a standard passive RFID tag is affixed to a disk contained in a flat structure. The disk is directed into a shielded region, when an attached box or container is oriented properly. When the box or container is in any other orientation orthogonal to the proper orientation, the disk becomes unshielded. This allows a signal to be received from the RFID tag, to indicate that the box is not properly oriented. A further embodiment of the invention is directed to sensor apparatus for use in detecting an improper orientation of a container or other object with respect to a substantially horizontal surface. The apparatus includes a structure having sides in spaced apart relationship, to define an enclosed space within the structure. Selected shielding material attached to the structure shields a specified region of the enclosed space against RF signals, the shielded region being located in the lowest portion of the enclosed space when the structure is in a reference orientation with respect to the horizontal surface. An RF sensor device is positioned in the enclosed space, the RF sensor device being sized to move freely within the space. A guide element mounted in the space guides the RF sensor device in moving between a shielded region and an unshielded region of the space, when the structure is correspondingly moved between its reference orientation and an improper orientation corresponding to an improper orientation of the object.  
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0007]     The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:  
         [0008]      FIG. 1  is a perspective view showing orientation sensors constructed in accordance with the invention.  
         [0009]      FIGS. 2-5  are views respectively showing an orientation sensor of  FIG. 1  in different positions, to illustrate the operation thereof.  
         [0010]      FIG. 6  is a sectional view taken along line  6 - 6  of  FIG. 2 .  
         [0011]      FIG. 7  is a sectional view taken along line  7 - 7  of  FIG. 4 .  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0012]     Referring to  FIG. 1 , there is shown a conventional six-sided shipping container, carton or box  100 , supported upon a substantially horizontal support surface  102 . More particularly, container  100  comprises six rectangular-shaped sides or panels  100 A- 100 F, wherein each side is in substantially orthogonal relationship with each adjacent side, that is, with each side with which it has a common edge. Side  100 A is the top side of container  100 , and side  100 B is the bottom side thereof. Thus, all the force received from surface  102  to support container  100  is received through bottom side  100 B.  FIG. 1  further shows sides  100 C- 100 F respectively extending between top side  100 A and bottom side  100 B. Bottom side  100 B shares common edges with each of the sides  100 C- 100 F, and is thus respectively adjacent thereto.  
         [0013]     Horizontal support surface  102  may comprise, for example, a floor or a load carrying shelf in a warehouse, or the bed of a truck provided to transport container  100 . Surface  102  may also be the top sides of one or more other containers that container  100  has been stacked upon. Regardless of the nature of horizontal surface  102 , it will frequently be very important to place and maintain container  100  on surface  102  so that container  100  is right side up. In such orientation, top side  100 A is the uppermost side of container  100 , and bottom side  100 B is in contact with horizontal surface  102 . This is the orientation shown in  FIG. 1 .  
         [0014]     Referring further to  FIG. 1 , there are shown orientation sensors  106  and  108 , each comprising an embodiment of the invention, respectively attached to adjacent sides  100 C and  100 F of container  100 . Sensors  106  and  108  are shown attached to the outside of container  100 , to avoid interfering with any product or items (not shown) that may be placed within container  100 . Alternatively, one or both of the orientation sensors could be attached to their respective sides within container  100 , to protect the sensors when container  100  is being handled. This mode of attachment would also prevent tampering with sensors  106  and  108 .  
         [0015]      FIG. 1  shows orientation sensor  106  comprising a comparatively flat chamber or other structure  110 , that contains a narrow enclosed space  112 . A disk  114 , formed of plastic or other suitable material that will readily occur to those of skill in the art, is placed within the space  112 . Disk  114  serves as a holder or carrier for an RFID tag  116  that is encased or embedded in the disk  114 . Disk  114  is sized to provide clearance between the sides of disk  114  and surfaces of structure  110  that serve to define boundaries of space  112 . By providing such clearance, disk  114  and its RFID tag  116  are able to move freely within enclosed space  112 .  
         [0016]      FIG. 1  further shows two linear members  118  and  120  contained in space  112  of structure  110 , the two members being joined together to form a “V” configuration. The linear members  118  and  120  are shown to incline downwardly toward the bottom of space  112 , as viewed in  FIG. 1 . Thus, the “V” formed by linear members  118  and  120  serves as a guide element for disk  114 , to guide the disk to the lower portion of space  112  when structure  110  is oriented as shown in  FIG. 1 . This orientation is referred to herein as the reference orientation of structure  110 . Disk  114 , when positioned between the two linear members near the point of the “V” formed thereby, is referred to herein as being in its home position.  
         [0017]      FIG. 1  further shows metal foil or other RF shielding material attached to structure  110 , to define a shielded region  122  of enclosed space  112 . Dimensions of the shielded region  122  are selected to ensure that disk  114  and RFID tag  116  are entirely within the shielded region  122 , whenever disk  114  is in its home position. Thus, whenever RFID tag  116  is in such position, it is prevented by the shielding material from either detecting or responding to RF signal transmissions. For example,  FIG. 1  shows an RF reader  124 , comprising an antenna and an RF transceiver, positioned to project RF signals toward container  100 . RFID tag  116  cannot detect these signals while in its home position.  
         [0018]     Orientation sensor  108  is substantially identical to sensor  106 , but is attached to side  100 F, orthogonal to side  100 C. Thus, orientation sensor  108  likewise comprises a structure  110  provided with an enclosed space  112 . The enclosed space of sensor  108  similarly contains linear members  118  and  120  forming a “V”, and further contains a movable disk  114  having an RFID tag  116  embedded therein. The disk resides in a home position defined by the linear members when the sensor  108  is in its reference orientation as shown by  FIG. 1 . Shielding material attached to the structure  110  of sensor  108  prevents its RFID tag  116  from detecting RF transmissions, when such device  116  is in the home position.  
         [0019]     It will be readily apparent that container  100  could be placed on horizontal surface  102  in any of six orientations. That is, any of the six sides  100 A- 100 F of container  100  could be placed downward, in contact with surface  102 . However, only one of these orientations is correct or proper, namely, the orientation in which side  100 B is the downward side. Accordingly, the orientation sensors  106  and  108  have been designed so that their respective disks  114  will each be in the home position when side  100 B is the downward side, as shown in  FIG. 1 . However, if container  100  is oriented so that any of its sides  100 A or  100 C- 100 F is the downward side, the disk  114  of one or both of the orientation sensors will roll out from the shielded region  122 , into an unshielded region  128  of enclosed space  112 . When this occurs, the RFID tag  116  in the disk  114  is enabled to detect RF signals.  
         [0020]     It is important to emphasize that in order for the orientation sensors  106  and  108  to operate as described herein, they must both be attached to container  100  so that their respective structures  110  are in their reference orientations when side  100 B is downward. As indicated above, the structure of each orientation sensor is in its reference position when the point of the “V” formed by linear members  118  and  120  points directly downward, as shown by  FIG. 1 . In this orientation, the “V” acts to guide disk  114  to the lower portion of space  112  and into shielded region  122 .  
         [0021]     To assist a user in correctly attaching the orientation sensors to a container  100 , each sensor is usefully provided with visual indicia, such as two red dots  126  positioned along the lower edge of structure  110 . When attaching an orientation sensor to container  100 , the user would ensure that the edge with the red dots was the downward edge of the sensor, when side  100 B was the downward side of container  100 .  
         [0022]     While  FIG. 1  shows an embodiment of the invention directed to a container having six rectangular sides, it is to be emphasized that embodiments of the invention can be used with other types of containers as well, such as drums and pyramid type containers. In fact, embodiments of the invention can be used to detect improper orientation of a wide range of container types, as well as other objects that have two or more possible orientations. The principal requirement for use of the invention is that such containers and other objects must have only one orientation that is proper (or only one orientation that is improper).  
         [0023]     Referring to  FIG. 2 , there is shown sensor  106  in its reference orientation, so that disk  114  is in the home position. As described above, this occurs when side  100 B of container  100  is placed downward, in contact with surface  102 . As likewise described above, in this position RFID tag  116  resides in shielded region  122  of enclosed space  112 .  
         [0024]     Referring to  FIG. 3 , there is shown orientation sensor  106  when container  100  is oriented so that its side  100 D is the downward side in contact with surface  102 . In this orientation of the container, sensor  106  is rotated 90 degrees clockwise from its reference orientation.  FIG. 3  shows that linear member  120  now inclines downwardly, away from shielded region  122 . Accordingly, disk  114  rolls down member  120  into unshielded region  128  of enclosed space  112 . This enables RFID tag  116  to detect RF signals.  
         [0025]     Referring to  FIG. 4 , there is shown orientation sensor  106 , when container  100  is oriented so that its side  100 A is the downward side in contact with surface  102 . In this orientation of the container, sensor  106  is rotated 180 degrees from its reference orientation. As shown by  FIG. 4 , in this position disk  114  is pulled downwardly by gravity and out of shielded region  122  into unshielded region  128  of enclosed space  112 . This enables RFID tag  116  to detect RF signals. While not shown, the disk  114  of orientation sensor  108  would also move downwardly, from the shielded region to the unshielded region of such sensor.  
         [0026]     Referring to  FIG. 5 , there is shown sensor  106  when container  100  is oriented so that its side  100 F is the downward side in contact with surface  102 . In this orientation of the container, sensor  106  is rotated 270 degrees clockwise from its reference orientation.  FIG. 5  shows that linear member  118  now inclines downwardly away from shielded region  122 . Accordingly, disk  114  rolls down member  118  into unshielded region  128 , enabling RFID tag  116  to detect RF signals.  
         [0027]     While not shown, if container  100  was oriented so that side  100 E was the downward side in contact with the surface  102 , orientation sensor  108  would be rotated 90 degrees clockwise from its position in  FIG. 1 . Accordingly, disk  114  of sensor  108  would move from its shielded region  122  to its unshielded region  128  in the manner described above. Moreover, if side  100 C became the downward side in contact with surface  102 , sensor  108  would be rotated 90 degrees counterclockwise, or 270 degrees clockwise, from its position shown in  FIG. 1 . This would again result in disk  114  of orientation sensor  108  moving from the shielded region  122  to the unshielded region  128  thereof.  
         [0028]     It is seen from the above that for each of the six possible orientations of container  100 , the RFID tags  116  of both orientation sensors  106  and  108  remain shielded from RF signals only when side  100 B is the downward side, as desired. When container  100  is in any of the other orientations, the RFID tag  116  of at least one of the sensors will be in its unshielded region  128 . Thus, improper orientation may be readily detected, by operating reader  124  to project an RF signal to container  100 . If an RFID tag  116  is unshielded, it will detect the signal, and transmit an identity code back to reader  124  in response. Accordingly, any RF transmission back to the reader from a tag  116  provides notice that container  100  is not in its proper orientation. It is to be noted that both of the orientation sensors  106  and  108  are necessary, in order to detect all possible improper orientations of the container  100 .  
         [0029]     In the embodiment described above, RFID tag  116  functions as a passive device, in responding to signals projected from reader  124 . In other embodiments, an active RF device could be substituted for RFID tag  116 . Such active device could project an RF signal to a detector at some distance from a container, to indicate improper orientation of the container.  
         [0030]     Referring to  FIG. 6 , there is shown structure  110  of sensor  106  formed by joining layers or sheets of plastic  602  and  604  around their respective edges. Usefully, the two sheets have the same length and width dimensions, and each sheet has a raised edge or lip extending around its perimeter, on one of its sides.  FIG. 6  shows sheets  602  and  604 , which may be clear or opaque, provided with raised edges  606  and  608 , respectively. To provide enclosed space  112 , the raised edges  606  and  608  are bonded together, such as by means of an adhesive  610 .  
         [0031]     Referring further to  FIG. 6 , there are shown linear members  118  and  120  and disk  114  contained in enclosed space  112 , as described above. Members  118  and  120  extend across the width of enclosed space  112 , for most effective RF shielding. Layers of metal foil  612  and  614 , or other suitable RF shielding material, are attached to plastic sheets  602  and  604 , respectively. The shielding layers provide shielded region  122  of enclosed space  112 , as likewise described above. To further enhance RF shielding, layers  612  and  614  are placed on the inner sides of sheets  602  and  604 , between the sheets and linear guide members  118  and  120 . To enable orientation sensor  106  to be readily attached to a container, a layer of adhesive  616  is applied to one of the sides of the sensor.  
         [0032]      FIG. 6  further shows the edge of disk  114  covered with a coating or layer of RF shielding material  618 . This acts to prevent RF signal from penetrating the unshielded region  122 .  
         [0033]      FIG. 7  shows a view of orientation sensor  106  that is similar to the view of  FIG. 6 . However, in  FIG. 7  the disk  114 , having moved into the unshielded region of enclosed space  112 , is not shown.  
         [0034]     The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.