DE202017103634U1 - RFID reader - Google Patents

Abstract

RFID reading device (10) having at least one antenna (20) for transmitting RFID signals to an RFID transponder (12) and / or for receiving RFID signals from an RFID transponder (12), and having an electronic unit ( 28), an RFID transceiver (18) connected to the antenna (20), a control and evaluation unit (22) for encoding an RFID information into the RFID signals and / or for reading an RFID information from the RFID Signals and at least one display device (24, 32), wherein the RFID reading device (10) in a housing (30) is housed, characterized in that the display device (24, 32) an indicator light source (24) as part of the electronic unit (28) and at least one optical waveguide (32), the indicator light of the indicator light source (24) leads out of the housing (30) and so makes visible from the outside that the electronics unit (28) has a further light emitter (26a) and / or a light receiver (26b) t and that the optical waveguide (32) and additional light of the further light emitter (26a) leads to the outside and / or additional light inwardly to the light receiver (26b).

Description

The invention relates to an RFID reading device for operating an RFID reading device according to the preamble of claim 1 or 10.

RFID reading systems are used to identify objects and goods and are used, among other things, to automate logistical movements. At an identification point, especially in the case of a change of the owner of the goods or a change of the means of transport, RFID transponders attached to the goods are read out and, if necessary, information is written back into the transponder. This leads to fast and traceable logistics movements. The captured information is used to control the routing and sorting of goods and products. Important applications for automatic identification are logistical distribution centers, such as parcel shippers, or baggage handling in airports.

A common place of use of an RFID reading system is the assembly on a conveyor belt on which the goods are conveyed, or in a so-called reading portal. By this is meant any passage which is equipped with one or more RFID readers and possibly other sensors. Objects are moved by means of a conveyor belt, a transport vehicle, such as a forklift, or by hand through the reading portal and thereby identified by their RFID transponder.

The RFID reader, which is also referred to as an interrogator, stimulates the transponder to emit the stored information, wherein passive transponders obtain the necessary energy from the transmission energy of the reading system. There are different frequency bands that RFID reading systems work with. In the established ultra-high frequency standard (UHF) ISO 18000-6, passive transponders are read out using the backscatter method.

An RFID reader usually has a wired switching input and wired data interfaces. The switching input is used to activate the reading field as required, ie to initiate an RFID reading process. The data interfaces not only serve to pass on the RFID information that has been read, but also make it possible to change configuration settings.

Conventionally, the connection to the inputs and outputs of the RFID reader via connectors, whereby a galvanic isolation via mounted behind the input jacks optocouplers is possible. This makes the required housing larger and its hermetic seal difficult. In addition, there must be contact between socket and plug.

Therefore, a non-contact interface would be desirable. There are standards for wireless light communication available, such as IrDA (Infrared Data Association), which is used in mobile computers and telephones, or the RC-5 known from remote controls. A magnetic interface through a reed contact or a Hall sensor would also be conceivable, but is less robust and flexible. The optical interface requires visual contact, which is problematic because the large-area antenna of the RFID reader regularly already largely completely loads the correspondingly aligned housing wall of the RFID reader.

As already mentioned, information that is frequently communicated is a trigger for an RFID reading process. In automated RFID reading systems, this trigger is typically provided by a sensor that detects the presence of an object in the reading field. For this purpose, one-way or retro-reflective light barriers are suitable as simple sensors. However, there are also miniaturized laser-based distance measuring sensors based on the time of flight principle, which measure distances in the range of a few meters and thus enable a more precise presence detection. This requires in each case an additional device, which must also be connected to the RFID reader, with the already described disadvantages of the required connections to the RFID reader also adds a considerable installation effort.

The US 2011/0018774 A1 discloses a compact circularly polarized antenna with a cavity for other devices. In this case, the antenna design is explained in detail, but not which device could be accommodated in the cavity in order to overcome the above-mentioned disadvantages.

The DE 10 2012 025 454 A1 describes a coupling of RFID and light barriers. The light barrier additionally secures the physical access of a person authorized by RFID, for example, to chemicals. However, the publication does not contribute to the question of how the functionality of the light barrier could be better compatible with an RFID reader or how its communication could be simplified.

The US Pat. No. 7,597,250 B2 deals with an RFID reader with a variety of interfaces, including an IR interface. It will, however did not discuss how the IR interface could be structurally better integrated into the RFID reader.

In the US 2016/0092704 A1 An RFID reader is integrated into a light bulb. The goal is not to combine the functionalities of light bulbs and RFID readers, but to simplify the installation of RFID readers in residential areas by exploiting already existing versions.

It is therefore an object of the invention to simplify the combination of RFID detection and other information.

This object is achieved by an RFID reading device for operating an RFID reading device according to claim 1. The RFID reading device initially comprises, as usual, an antenna, a transceiver and an electronic unit with the required control and evaluation functionality in order to exchange RFID signals and thus the information embedded therein with RFID transponders. In addition, a display device is provided, via which, for example, a status or a feedback message is displayed. The electronic unit is protected inside a housing.

The invention is based on the basic idea of providing additional functionality without additional connections and, if possible, using components multiple times. There is an indicator light source of the display, such as an LED, as part of the electronics unit within the housing. It is therefore not visible. An optical waveguide leads indicator light of the indicator light source to the outside, ie to the surface of the housing, for example, past the antenna. The optical waveguide acts as a passive, externally visible extension of the indicator light source. In addition, a further light emitter and / or a light receiver are provided in the electronic unit. In order to guide the corresponding additional light into the RFID reading device or out of the RFID reading device, the optical waveguide is used again. In this way, the optical fiber has a dual function for the display and the additional light.

The invention has the advantage that in an especially simple manner with the further light emitter and / or the light receiver, an optical system is introduced into the RFID reading device. The optical fiber replaces a conduit connection, which would have to be laboriously connected with connectors and cables and would hinder a hermetic sealing of the housing. The passive or wireless connection by means of optical waveguide galvanic isolation is ensured to the electronic unit.

The additional light preferably has a wavelength outside the visible spectrum. Thus, the additional light can not be perceived as an indicator. In addition, the display light and additional light are spectrally decoupled, so that there can be no interference in the transmission through the optical waveguide. By wavelength is meant also a wavelength range. Accordingly, the light emitter generates additional light in the wavelength range, or the light receiver is at least sensitive to additional light in the wavelength range. The additional light is in particular infrared light.

The electronics unit preferably has an optical communication interface, wherein the further light transmitter and / or the light receiver are part of the optical communication interface. The additional light is therefore the light used for the communication. In this way, the RFID reader is provided with an optical interface, wherein the optical fiber has a dual function for display and wireless optical communication. In this case, bidirectional communication is preferably provided, and accordingly the further light emitter and the light receiver are present. However, a unidirectional communication is at least conceivable if the obvious limitations for saving the further light emitter or the light receiver are accepted. The data communication via the optical communication or data interface can follow a standard such as IrDA or RC-5, with modifications and completely own protocols remain possible. The optical communication interface can be used, for example, to configure or trigger reading events.

Preferably, an external additional sensor is provided, in particular an optoelectronic sensor which is in communication with the control and evaluation unit via the optical communication interface. Because of the wireless communication, no special measures are required for connection. The sensor is external, so it is located outside the housing and includes its own sensors and control and evaluation functionality. However, a mechanical connection, such as mounting the sensor on the housing or the common housing of the housing of the actual RFID reading device and the sensor are possible.

The RFID reading device preferably has an integrated additional optoelectronic sensor, wherein the further light emitter and / or the light receiver are part of the additional sensor. In this case, the additional light is the sensor light with which the additional sensor operates, not the light for optical communication. This again results in a dual function of the optical waveguide, now for display and optical object detection. Another overload of functionality with an optical communication interface is conceivable.

In this embodiment, the RFID reading device is itself capable of optically detecting objects, and uses the optical waveguide to guide transmitting and / or receiving light to the outside or to the inside. In this case, various sensor principles are conceivable in which the integrated additional sensor works for itself, as in the case of a light scanner, or the transmitting or receiving part of a two-part sensor, as in the case of a single-use photoelectric barrier. An external additional sensor is no longer required, but is not excluded if necessary to collect further information.

The additional sensor, be it an external or integrated additional sensor, is preferably designed to detect an object in a read area and then trigger an RFID read operation.

The additional sensor thus works as a switch and ensures that the reading field is only activated when an object (in the detection area) is present.

The additional sensor is preferably a light barrier or an especially distance-measuring light sensor. These are in each case simple, well-proven and available sensors for the reliable detection of objects, for example in the reading field. As usual, the light barrier generates switching events depending on whether its beam is interrupted by an object or not. A distance-measuring light scanner can measure the distance to a detected object in a triangulation or with a light transit time method, so that even more precise criteria can be established here, which cause object detection, a reading event or another desired reaction of the RFID reading device.

The optical waveguide is preferably arranged on an edge or corner of the antenna. The optical fiber ends there or at least passes there. By means of interfaces in a correspondingly acute angle to the guided light or roughening, it can be ensured that light is switched on and off and thus, in particular, a display becomes visible. The antenna is typically sized for the housing, so there is no space left next to it to keep the device slim. The optical fiber can therefore be placed in a recess of the antenna at an edge or corner to allow a compact construction. Depending on the structure of the antenna but is also conceivable to guide the optical waveguide through the antenna and not only at edges and corners.

The antenna preferably has a quadrangular, in particular square, basic shape, and the optical waveguide is arranged at at least one of the four corners. The square basic shape of the antenna preferably embosses the housing and thus the RFID reading device. The arrangement of the optical waveguide at a corner has structural advantages and prevents unwanted effects on the antenna. In addition, this makes the display easily visible, especially from all sides, when the optical fiber or multiple optical fibers are arranged at all four corners. The same applies to optical communication or optical object detection by means of an integrated additional sensor.

• 1 eine schematische Darstellung des Aufbaus einer RFID-Lesevorrichtung;
• 2 eine Darstellung einer RFID-Lesevorrichtung mit integriertem Sensor zur Abstandsmessung;
• 3 eine Darstellung einer RFID-Lesevorrichtung mit drahtloser Kommunikation mit einem externen Sensor zur Abstandsmessung;
• 4 eine Darstellung einer RFID-Lesevorrichtung mit durch Lichtwellenleiter realisierter Anzeige an ihren vier Ecken;
• 5 eine Darstellung einer RFID-Lesevorrichtung mit integriertem Sensor in Form einer Reflexionslichtschranke;
• 6 eine Darstellung einer RFID-Lesevorrichtung mit einem integrierten Lichtempfänger einer Einwegelichtschranke; und
• 7 eine Darstellung einer RFID-Lesevorrichtung mit einem integrierten Lichtsender einer Einwegelichtschranke sowie drahtloser Kommunikation mit einem Lichtempfänger der Einwegelichtschranke.

The invention will be explained in more detail below with regard to further features and advantages by way of example with reference to embodiments and with reference to the accompanying drawings. The illustrations of the drawing show in:

• 1 a schematic representation of the structure of an RFID reading device;
• 2 a representation of an RFID reading device with integrated sensor for distance measurement;
• 3 a representation of an RFID reading device with wireless communication with an external sensor for distance measurement;
• 4 a representation of an RFID reader with realized by optical waveguide display at its four corners;
• 5 a representation of an RFID reading device with integrated sensor in the form of a reflection light barrier;
• 6 a representation of an RFID reader with an integrated light receiver of a through-beam sensor; and
• 7 a representation of an RFID reading device with an integrated light emitter of a through-beam sensor and wireless communication with a light receiver of the through-beam sensor.

1 shows a schematic representation of the structure of an RFID reading device 10 , The RFID reader 10 communicates with an RFID transponder 12 that is attached to an object 14 is appropriate and located in a reading field 16 the RFID reading device 10 located. To do this, an RFID transceiver exchanges 18 via an antenna 20 , For example, a patch antenna, RFID signals with the RFID transponder 12 out. The term transceiver is purely functional, the separation into separate transmitter and receiver would also be conceivable.

The RFID transceiver 18 is with a control and evaluation unit 22 connected, which evaluates the received RFID signals or information as RFID signals to the RFID transponder 12 sends. The over the antenna 20 radiated carrier signal is at passive RFID transponder 12 also used for its supply. The RFID communication is known per se and follows, for example, the already mentioned above ultra-high frequency standard ISO 18000-6. That is why RFID communication and the design of the RFID reader 10 not accurate and on the internal structure of the RFID transponder 12 , who also has an antenna, for example, did not go into detail.

The control and evaluation unit 22 is still with an indicator light source 24 or multiple indicator light sources, such as one or more LEDs. Another connection consists of an optical communication interface 26 Here, bidirectional with a light transmitter 26a and a light receiver 26b is designed. In other embodiments, only one light emitter 26a or just a light receiver 26b be provided. In still other embodiments are light emitters 26a and / or light receiver 26b also provided, but not as part of an optical communications interface 26 but an integrated optoelectronic sensor. The basic structure also corresponds to the 1 , so that this is not shown separately. The further electronics of the optical communication interface 26 or the integrated sensor is here as part of the control and evaluation unit 22 understood, but could also be implemented separately.

Preferably, the indicator light source operates 24 in the visible spectral range, to be perceived by a human observer, and light emitters 26a or light receiver 26b in the invisible spectral range, for example in the infrared range. The signals of the light transmitter 26a are not intended for the human eye, and in addition the different functions differ in the spectral range in order to exclude collisions from the outset.

The RFID transceiver 12 , the control and evaluation unit 22 , the indicator light source 24 as well as light emitters 26a or light receiver 26b are part of an electronics unit 28 in a housing 30 the RFID reader 10 is housed. The electronics unit 28 can be distributed over several blocks. The housing 30 or the housing 30 after at least one side final antenna 20 prevents the indicator light source 24 is visible from the outside. For the same reasons, the light of the light transmitter reaches 26a not readily to the outside or no light to the light receiver 26b ,

That's why an optical fiber 32 provided, which leads the light from the inside out and vice versa. Therefore, an outer end region functions 34 of the optical fiber 34 as an externally visible indicator. As the optical fiber 32 In addition, depending on the embodiment, light for wireless communication or sensor light from the light emitter may be perceived as having a dual function 26a outwards or inwards to the light receiver 26b guided. The end area 34 is the corresponding coupling point. It is not mandatory that this is an end area 34 It can, for example, by roughening or similar measures somewhere on the optical fiber 32 be provided for a desired light coupling.

Based on 2 to 7 Various exemplary embodiments will now be described, such as one by light emitters 26a or light receiver 26b built wireless communication or an integrated optoelectronic sensor formed therewith can be used.

2 shows an RFID reader 10 with integrated sensor for distance measurement. The distance of an object 14 is determined by a known method such as triangulation or a time of flight measurement. The measured distance is symbolized by distance arrows. The integrated sensor can be anywhere in the RFID reader 10 be housed because of the optical fiber 32 the light leads internally. The end area 34 or more generally, the coupling point, in turn, may be in any position on the housing 30 are located. In this case, this is purely exemplary central. Also, the use of multiple sensors or at least several coupling points of one or more optical fibers 32 for example centrally and / or in some or all corners is conceivable. In addition to the distance, the light intensity represents a possible measure, that of the reflecting object 14 which depends on the light emitter 26a is illuminated. The measured quantities distance and / or light intensity are in the control and evaluation unit 22 evaluated and used, for example, the reading field 16 to activate and trigger an RFID reading once an object 14 is in a certain distance range and in particular falls below a distance.

3 shows an RFID reader 10 with wireless communication to an external sensor 36 for distance measurement. light source 26a and light emitters 26b So here they are not used for their own integrated optical object detection, but for a wireless communication. The data transmission takes place for example via infrared via a standard such as IrDA, RC-5 or another general or proprietary protocol.

The external sensor 36 is shown here as a distance-measuring light sensor, which sends its measured variables or a result derived therefrom, such as a switching state, wirelessly to the RFID reading device 10 transfers. Again, this can serve to trigger an RFID reading once an object 14 is in a certain distance range.

The representation of a distance-measuring light sensor is purely exemplary. Alternatively, one-way or retro-reflective sensors and other opto-electronic and other presence detection sensors may be used, such as magnetic, inductive, capacitive or radar sensors. Also, the use of multiple external sensors 36 is conceivable, which then directly or via an acting as a master external sensor 36 communicate wirelessly with the RFID reader.

4 shows an RFID reader 10 with by optical fiber 32 realized display at its four corners. These are at the corners end areas 34a-d or generally coupling points of one or more optical fibers 32 intended. Illustrated is in 4 the function as an indicator. In addition, the double function already described several times as an optical data interface or for guiding sensor light of an integrated sensor. The provision of coupling points on all four corners ensures good visibility of the display from all sides, and accordingly for a robust, reliable wireless communication or sensor function. It would also be conceivable if the antenna design of the antenna 18 this allows, at any point of the antenna as in particular in the center of a bore or passage opening for the optical waveguide 32 to install.

5 shows an RFID reader 10 with integrated sensor in the form of a reflection light barrier. The construction is similar to that in 2 , but now no distances are measured, but as usual with a light barrier, a beam interruption by an object 14 is detected. This is the presence of the object 14 determined and then triggered, for example, an RFID reading. A reflection light barrier contains light emitters 26a and light receiver 26b on the same side of the monitoring beam, and on the opposite side is a reflector 38 arranged.

6 and 7 each show an RFID reader 10 with an integrated sensor in the form of a through-beam sensor. In contrast to a reflection light barrier active Kopmonenten are provided with a one-way light barrier on both sides of the monitoring beam, namely light emitter and light receiver.

6 shows a variant in which the integrated light receiver 26b as counterpart an external light transmitter 40 is provided, the a focused light beam in the direction of the RFID reading device 10 sending out. In this case, the relevant received signal becomes in the light receiver 26b and thus in the RFID reader 10 generates, so there beam interruptions and thus the presence of an object 14 can be recognized.

7 shows the alternative variant in which to the integrated light emitter 26a as counterpart an external light receiver 42 is provided. The light transmitter 26a sends a focused light beam to the external light receiver 42 where a beam interruption is detected on the received signal. In this case, a wireless transmission of the received signal or of a measured value or switching state obtained therefrom takes place by the external light receiver 42 to the RFID reader 10 ,

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2011/0018774 A1 [0009]
• DE 102012025454 A1 [0010]
• US 7597250 B2 [0011]
• US 2016/0092704 A1 [0012]

Claims (9)

RFID reading device (10) having at least one antenna (20) for transmitting RFID signals to an RFID transponder (12) and / or for receiving RFID signals from an RFID transponder (12), and having an electronic unit ( 28), an RFID transceiver (18) connected to the antenna (20), a control and evaluation unit (22) for encoding an RFID information into the RFID signals and / or for reading an RFID information from the RFID Signals and at least one display device (24, 32), wherein the RFID reading device (10) in a housing (30) is housed, characterized in that the display device (24, 32) an indicator light source (24) as part of the electronic unit (28) and at least one optical waveguide (32), the indicator light of the indicator light source (24) out of the housing (30) and so makes visible from the outside, that the electronic unit (28) has a further light emitter (26a) and / or a light receiver (26b) aufwei st and that the optical waveguide (32) and additional light of the further light emitter (26 a) leads to the outside and / or additional light inwardly to the light receiver (26 b). RFID reading device (10) according to Claim 1 wherein the additional light has a wavelength outside the visible spectrum. RFID reading device (10) according to Claim 1 or 2 wherein the electronic unit (28) has an optical communication interface (26), and wherein the further light emitter (26a) and / or the light receiver (26b) are part of the optical communication interface (26). RFID reading device (10) according to Claim 3 , wherein an external additional sensor (36) is provided, in particular an optoelectronic sensor which communicates with the control and evaluation unit (22) via the optical communication interface (26). RFID reading device (10) according to one of the preceding claims, comprising an integrated additional optoelectronic sensor (26a, 26b, 22), wherein the further light transmitter (26a) and / or the light receiver (26b) part of the additional sensor (26a, 26b , 22). RFID reading device (10) according to Claim 4 or 5 wherein the additional sensor (26a, 26b, 22; 36) is adapted to detect an object (14) in a reading area (16) and then to initiate an RFID reading operation. RFID reading device (10) according to one of Claims 4 to 6 , wherein the additional sensor (26a, 26b, 22, 36) is a light barrier or a light sensor which measures the distance in particular. An RFID reading device (10) according to any one of the preceding claims, wherein the optical waveguide (32) is disposed at an edge or corner of the antenna (20). RFID reading device (10) according to any one of the preceding claims, wherein the antenna (20) has a quadrangular, in particular square basic shape and the optical waveguide (32) is arranged at at least one of the four corners.

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