Identification device for objects with a transponder and a corresponding method

Abstract

In order to achieve an optimal identification with an identification device for objects that comprise a transponder and are transported by means of a conveyor device through a closed tunnel (2), it is proposed that the antenna device of the transmitting and receiving device (10) comprises at least three sequentially arranged coil-shaped antennas (4, 6, 8). They surround the tunnel (2), each lying in a plane and representing a linearly independent system. The antennas (4, 6, 8) are operated in a multiplexer mode.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Further details, advantages and features of the subject of the present invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein an identification device according to this invention and an identification method for objects with a transponder are explained in an exemplified form. In the following drawings

FIG. 1 shows an identification device according to a preferred embodiment of the present invention, in a perspective representation where the antennas are arranged under a shielding,

FIG. 2 shows the identification device according to FIG. 1, without the shielding, so that the antennas and their tuning devices are visible;

FIG. 3 shows the tunnel of the identification device according to FIG. 1, in a schematic representation; and

FIG. 4 shows a schematic representation of the circuitry logics for addressing the antennas according to FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

In an embodiment, the tunnel denoted as 2 in FIGS. 1 to 3 is provided with three antennas 4, 6 and 8 which are laid out as coils around the tunnel. On the bottom surface of tunnel 2 there is arranged conveyor device 3, namely a transport band for the transport containers containing the objects provided with transponders. In FIG. 2 the identification device is shown without the shielding 11 shown in FIG. 1, so that the tuning devices 22, 24 and 26 can be seen.

The normal of the plane of the first antenna 4 is parallel to the transport direction x of the conveyor band, and this direction is indicated as x′ in FIG. 1. In the present embodiment the first antenna 2 coincides with the tunnel entrance. The second antenna 6 is tilted (vertically) with respect to the first antenna 4 by an angle of about 45°. The normal of its plane is indicated as y′ in FIG. 1. An important feature of the present embodiment is that the center of the second antenna 6 lies approximately in the middle of the tunnel and is thus substantially displaced from the first antenna, and that the two antennas 4 and 6 neither contact nor overlap each other, but rather have a distance of about ⅓ of the tunnel length. The third antenna 8 is (laterally) twisted with respect to the first antenna 4 by an angle of about 45°. The normal of its plane is indicated as z′ in FIG. 1. A further important feature of the present embodiment is that a lateral edge of the third antenna 6 is approximately located at the end of the tunnel, whereas the other lateral edge is arranged at a substantial distance from the second antenna 6, and that the two antennas 6 and 8 also do not contact or overlap each other, but rather that their centers also have a distance of about ⅓ of the tunnel length.

In the present embodiment, the antennas 4, 6 and 8 are addressed and read out by means of a switching device 10 with reading device, as shown schematically in FIG. 3.

The switching device has a multiplexer 14 that selectively distributes the electrical signals of the antenna amplifier 12 by means of a respective switch 16, 18 or 20 and a tuning device 22, 24 or 26 associated with one of the antennas 4, 6, or 8 and reads out the incoming signals from a respective one of these antennas. Further electronic circuitry is known in the art and will not be detailed in the description of the present embodiment.

Multiplexer 14 of switching circuit 10 is controlled in such way—in the present embodiment by means of a computer—as to perform one of the two procedures described hereinbelow.

For comparatively small containers 28 for the objects to be identified, i.e. for containers that are not larger than the distance between the first antenna plane x′ to the third antenna plane z′, in which case it is not probable that any transponders are already being identified with the third antenna 8 while other transponders are still being identified with the first antenna 4, the control is set up so that initially it activates the first antenna 4. During identification of transponders with the first antenna 4 as many transponders as possible are identified therewith and, simultaneously, the second antenna 6 is alternatingly activated in the multiplexer mode. At this point both activated antennas identify transponders until the first antenna 4 no longer identifies any transponders and is deactivated. In this moment, the third antenna 8 is activated in the multiplexer mode. By means of the second and third antenna 6 and 8, as many transponders as possible are identified until the second antenna 6 no longer identifies any transponders. Thereafter, the third antenna 8 is kept in operation until it no longer identifies any transponders. Subsequently, the processing device 10 carries out a processing and an output and/or storage of the results.

For comparatively large containers 28 that are larger than the distance between the first antenna plane x′ to the third antenna plane z′, in which case it is probable that transponders will already be identified with the third antenna 8 while other transponders are still being identified with the first antenna 4, the control is set up so that it also first activates antenna 4. During identification of transponders with the first antenna 4, as many transponders as possible are identified therewith, and as soon as the first transponders are identified, the second antenna 6 is alternatingly activated in the multiplexer mode. Also the second antenna activates as many transponders as possible, but the third antenna 8 is activated already when transponders are being identified with the second antenna 6. The first antenna 4 is deactivated when it no longer identifies any transponders for a specific time. Also the second antenna 6 is deactivated when it no longer identifies any transponders for a specific time. The third antenna 8 is again kept in operation until it no longer identifies any transponders for a specific time. Subsequently, the processing device 10 carries out a processing and an output and/or storage of the results.

In general, an identification device according to the present embodiment of the invention will always be fed with a specific type of containers, so that one of the two previously described operating modes can be permanently set up in the identification device. However, it is also possible—according to the present embodiment—to select one of the two operating modes via the computer or another inputting device.

In the present embodiment, the transmitting and receiving device 10 is set up in such way that upon identification of each transponder it commands the same to switch into a mode in which the transponder does not respond during the reception of signals and—if the transponder is configured accordingly and has a corresponding power supply for storing its mode—also for a time thereafter that corresponds to the transport time from a given antenna until the end of the tunnel.

In a second, alternative embodiment of the present invention the conveyor device can move the container 28 in Tunnel 2 in both directions. Accordingly, if the number of objects in the container 28 being transported through the tunnel is known exactly or approximately, it is possible to ascertain after the passage whether identification of all or at least nearly all transponders in the container was achieved. If, after such a container has passed through the tunnel 2, the number of identified transponders does not correspond to the number of objects in the container 28 that should have a transponder, according to the present embodiment the transport direction of the conveyor device is changed after passage of the container 28 so that the container 28 is transported back into the reading zone of the third, of the third and second or of all three antennas 8, 6, 4. For this purpose, the conveyor device is configured in such way that the objects to be identified are movable in two directions. In the present embodiment, the amount of deficit is used to determine whether container 28 is transported back into the reading zone of the third, second or even of the first antenna 8, 6, or 4, respectively. Alternatively, the expected number of transponders may be determined in a different way, e.g. by weighing of the container 28 on the conveyor is band by means of a corresponding weighing device so as to determine the expected number of objects in the container 28, if the container weight and the weight of the single objects provided with a transponder is known and the objects all have the same weight.

In a further embodiment, which may be combined with the first or the second embodiment, the conveyor device is configured in such way that the arrangement of the transponders is movable transversally to the transport direction during the reading process by means of a non-linear movement profile—in the present example by means of a shaking movement. If in certain container loads one cannot rule out that two or more transponders will be so close to each other that they cannot be identified, such shaking profile can be used to change the arrangement of transponders during the reading process so as to increase the number of transponders that are identifiable upon transit on the transport band.

LIST OF REFERENCE NUMERALS

• 2 identification tunnel
• 3 conveyor device
• 4 first antenna
• 6 second antenna
• 8 third antenna
• 10 switching device with reader device
• 11 shielding
• 12 antenna amplifier
• 14 multiplexer
• 16 switch for first antenna
• 18 switch for first antenna
• 20 switch for third antenna
• 22 antenna tuning device for first antenna
• 24 antenna tuning device for second antenna
• 26 antenna tuning device for third antenna
• 28 container for testing body
• x transport direction of container
• x′ normal of first antenna plane
• y′ normal of second antenna plane
• z′ normal of third antenna plane

Claims

1. An identification device for objects, each of which comprises a transponder, with a conveyor device for the objects to be identified, the conveyor device comprising a tunnel through which the objects to be identified are transportable, a transmitting and receiving device for communication with the transponders of the objects to be identified, the transmitting and receiving device comprising an processing device and an antenna device, the antenna device comprising at least three sequentially arranged coil-shaped antennas that surround the tunnel, at least three of the antennas that surround the tunnel lying each in a different plane (x′, y′, z′), the planes (x′, y′, z′) representing a linearly independent system wherein said antenna planes (x′, y′, z′) do not intersect or contact each other within the tunnel.

2. The identification device according to claim 1, wherein said transmitting and receiving device (10) comprises a multiplexer (14) that is set up in such a way that the antennas (4, 6, 8) are operable in the multiplexer mode.

3. The identification device according to claim 1, wherein said antenna planes (x′, y′, z′) have a displacement of at least 10 mm within the tunnel (2).

4. The identification device according to claim 1, wherein one of said planes (x′) is perpendicular to the normal of the conveyor band.

5. The identification device according to claim 4, wherein said transmitting and receiving device is set up in such a way that initially it activates the first antenna, whereupon during identification of transponders with the first antenna it identifies as many transponders as possible, and that following the first identification of transponders with the first antenna it alternatingly activates the second antenna in a multiplexer mode and identifies as many transponders as possible with these two antennas until the first antenna no longer identifies any transponders, whereupon it alternatingly activates the third antenna in a multiplexer mode and identifies as many transponders as possible by the second and the third antenna until the second antenna no longer identifies any transponders, whereupon it keeps the third antenna in operation until it no longer identifies any transponders, and that subsequently the processing device performs the processing and an output and/or storage of the results.

6. The identification device according to claim 4, wherein said transmitting and receiving device is set up in such a way that initially it activates the first antenna, whereupon during identification of transponders with the first antenna (4) it identifies as many transponders as possible, and that following the first identification of transponders with the first antenna it alternatingly activates the second antenna in a multiplexer mode and it identifies as many transponders as possible with these two antennas, whereupon already during identification of transponders with the second antenna it activates the third antenna, it deactivates the first antenna, when the latter no longer identifies any transponders for a specific time, it deactivates the second antenna, when the latter no longer identifies any transponders for a specific time, and it keeps in use the third antenna, until the latter no longer identifies any transponders for a specific time, and that subsequently the processing device performs the processing and an output and/or storage of the results.

7. The identification device according to claim 1, wherein said transmitting and receiving device is set up in such a way that upon identification of each transponder it commands said transponder to switch into a mode in which the transponder does not respond during the reception of signals and for a time thereafter.

8. The identification device according to claim 1, wherein said device is set up in such a way that the objects to be identified are movable in two directions.

9. The identification device according to claim 8, wherein it is set up in such a way that a specific number of transponders to be identified can be predefined, and that in the presence of a deficit of predetermined amount after the completion of the identification process the conveyor direction of the conveyor device is switched into the reading range of one, two or three antennas so as to allow identification of further transponders not identified as yet.

10. The identification device according to any one of claims 1, wherein said conveyor device is set up in such a way that the arrangement of the transponders can be changed during the reading process by means of a non-linear movement profile in another direction than the conveyor direction, so as to increase the number of identifiable transponders upon passing onto the conveyor band.

11. A method for identifying objects, each of which comprises a transponder, by means of an identification device that comprises a conveyor device for the objects to be identified, the conveyor device comprising a tunnel, through which the objects to be identified are transportable, the identification device further comprising a transmitting and receiving device for communication with the transponders of the objects to be identified, the transmitting and receiving device comprising an antenna device and an processing device, the antenna device comprising at least three sequentially arranged coil-shaped antennas, the antenna coils surrounding the tunnel, operating the antennas in the multiplexer mode.

12. The method for identifying objects according to claim 11, wherein said transmitting and receiving device initially activates the first antenna, whereupon during identification of transponders with the first antenna it identifies as many transponders as possible, then it alternatingly activates the second antenna in a multiplexer mode and identifies also as many transponders as possible with this antenna until the first antenna no longer identifies any transponders, whereupon it alternatingly activates the third antenna in a multiplexer mode and identifies as many transponders as possible with the second and the third antenna until the second antenna no longer identifies any transponders, whereupon it keeps the third antenna in operation until it no longer identifies any transponders, and that subsequently the processing device performs the processing and an output and/or storage of the results.

13. The method for identifying objects according to claim 11, wherein said transmitting and receiving device initially activates the first antenna, whereupon during identification of transponders with the first antenna it identifies as many transponders as possible, then it alternatingly activates the second antenna in a multiplexer mode and identifies also as many transponders as possible with this antenna, activates the third antenna during identification of transponders with the second antenna, deactivates the first antenna when the latter no longer identifies any transponders for a specific time, deactivates the second antenna when the latter no longer identifies any transponders for a specific time, and keeps in use the third antenna until the latter no longer identifies any transponders for a specific time, the processing device subsequently performing the processing and an output and/or storage of the results.

14. The method for identifying objects according to claim 11, wherein said transmitting and receiving device upon identification of each transponder commands said transponder to switch into a mode in which the transponder does not respond during reception of signals and for a time thereafter.

15. The method for identifying objects according to claim 11, wherein said conveyor device switches conveyor direction and conveys the objects back into the reading range of one, two or three antennas when a predefined number of transponders to be identified is missed by a deficit of predetermined amount after completion of the identification process.

16. The method for identifying objects according to claim 11, wherein said conveyor device changes the arrangement of the transponders during the reading process by means of a non-linear moving profile in another direction than the conveyor direction.