Multiple technology data reader for bar code labels and RFID tags

[0002] The field of the present invention generally relates to optical systems for data reading and radio frequency identification (RFID) systems for remote identification of physical objects. More particularly, the field of the present invention relates to a multiple technology data reader for reading bar code labels and RFID tags.

[0003] Optical reading systems are widely used to read data, in the form of bar codes or other encoded symbols, printed on various objects. These systems may be used for a wide variety of applications, such as inventory control and point-of-sale transactions in retail stores.

[0004] Optical reading systems may employ an optical reader that illuminates a bar code (for example) and detects light reflected from the bars and spaces of the code. In one type of optical reading system, an optical beam of light produced by a laser diode is used to scan the bar code symbol. The bars of the code absorb light, while the spaces of the code reflect light. The resulting pattern of reflected light is detected by circuitry within the optical reader. The reflected light can be detected by a photocell, photodiode, CCD array, or CMOS array sensor.

[0005] After the bar code data is received by the optical reader, the detected signal may be subject to filtering, amplification, digitization and decoding. The detected signal may be transmitted to a processor or decoder located within the optical reader, or to a separate device such as a personal computer. In systems where the signal is conveyed to a separate device, the optical reader may be connected to the external data processor by means of cables or via a wireless communication link. The wireless communication link can be implemented using radio frequency (RF) equipment or infrared (IR) transmitters and receivers, for example.

[0006] In retail stores, optical reading systems may be set up at check-out stands and may be built into a horizontal check-out counter, so that items to be purchased can be placed on a counter, deck or conveyor, and then moved through an optical reading area. Alternatively, the optical reader may be a handheld device, in the shape of a wand or gun. Typically, in operation these handheld devices are pointed or aimed at the retail item, so that a wide range of information, including price, may be read from the object.

[0007] RFID systems can be used to identify retail items by reading electronic information stored within tags or labels on the items. These systems can be used to remotely identify physical objects by the response signal sent back by the tag.

[0008] An RFID system typically employs at least two components, a “transponder” or “tag,” which is attached to the physical item to be identified, and a “reader,” which sends an electromagnetic signal the transponder and then detects a response. Typically, the reader emits a RF signal which is received by the transponder, after the transponder comes within an appropriate range. In response to the signal from the reader, the transponder sends a modulated RF signal sent back to the reader. The reader detects this modulated signal, and can identify the transponder by decoding the modulated signal. After identifying the transponder, the reader can either store the decoded information or transmit the decoded signal to a computer.

[0009] The transponder used in an RFID system may be either “passive” or “active.” A passive transponder can be a simple resonant circuit, including an inductive coil and a capacitor. Passive transponders are generally powered by the carrier signal transmitted from the reader. Active transponders, on the other hand, generally include transistors or other active circuitry, and require their own battery source.

[0010] In some retail environments, both bar code labels and RFID tags are attached to various retail items. In these environments an optical reader is needed to read the bar code label, and a separate RFID reader is needed to detect and identify the RFID tag. Without a dual-technology device embodying both bar code and RFID reading functionality, two separate devices would be needed to read both bar codes and RFID tags. Thus, there is a present need for a dual-technology bar code/RFID reader.

[0011] One example of a hand-held dual technology identification tag reading head, that can read both bar codes and RFID tags is described in U.S. Pat. No. 5,382,784, issued to Eberhardt. However, the present inventor has recognized that the system described in that patent has several drawbacks. For example, in that system, in order to operate the hand-held reader, a user must selectively actuate either the bar code reader or RFID tag reader. Moreover, at any given time, only one of readers is powered. Therefore, simultaneous operation of both the bar code reader and the RFID tag reader is not possible. In addition, when the RFID reader is selected, the output signal from the RFID reader must be converted to a format corresponding to the output signal from the bar code reader, in order to be fed into a single input port of a data receiver.

[0012] Thus, the present inventor has determined it would be advantageous to provide a dual-technology bar code/RFID reader which is capable of reading bar codes and RFID tags simultaneously, and which is more versatile than the previously described devices.

[0013] The present invention relates to a multiple technology data reader for reading optical code labels and RFID tags. In one embodiment, the multiple technology data reader includes an optical code reader sub-system and an RFID reader sub-system, each electronically connected to a device microcontroller. The device microcontroller includes a device interface for the bar code reader subsystem, and a device interface for the RFID reader subsystem. Both of these device interfaces are connected to a device communications, control and power unit. The device microcontroller is connected to a host computer via a computer bus, such as a universal serial bus (USB).

[0014] In another embodiment, the multiple technology data reader includes an optical code reader and an RFID reader, each electronically connected to a device microcontroller. The device microcontroller includes a first decoder and control means for the bar code reader, and a second decoder and control means for the RFID reader. Both of these decoder and control means are connected to a device communications, control and power unit. The device microcontroller is connected to a host computer via a computer bus, such as a USB.

[0015] In another embodiment, the multiple technology data reader includes a bar code reader and an RFID reader, each connected to a device microcontroller. The device microcontroller includes a bar code pre-processor and an RFID pre-processor, each of which are connected to a single decoding and control means. The decoding and control means is connected to a device communications, control and power unit. The device microcontroller is connected to a host computer via a USB.

[0016] Further variations, modifications and alternative embodiments are also described herein.

[0017] FIG. 1 is a system block diagram of a multiple technology data reader, according to an embodiment of the present invention;

[0018] FIG. 2 is a functional block diagram of a multiple technology data reader, according to an embodiment of the present invention;

[0019] FIG. 3 is a block diagram illustrating the logical connections for a compound multiple technology data reader according to an embodiment of the present invention;

[0020] FIG. 4 is a block diagram illustrating the logical connections for a composite or complex multiple technology data reader according to another embodiment of the present invention;

[0021] FIGS. 5-10 illustrate six alternate circuit diagrams for different embodiments of the multiple technology data reader as described herein.

[0022] Preferred embodiments will now be described with reference to the drawings.

[0023] FIG. 1 is a system block diagram of a preferred embodiment of a multiple technology data reader 10. The multiple technology data reader 10 shown in FIG. 1 includes an optical code reader, such as a bar code reader 12, a low frequency RFID reader 14a, and/or a high frequency RFID reader 14b. The bar code reader 12, a low frequency RFID reader 14a, and/or a high frequency RFID reader 14bare each connected to a device communications, control and power unit 16. While it is convenient to combine communications, control and power functionality within the device communications, control and power unit 16, such functionality can also be separated into different units, either in the FIG. 1 embodiment or the other embodiments described later herein.

[0024] The device communications, control and power unit 16 is preferably connected to a host device 30 over a USB 20, which comprises a serial communications signal line 27 and a set of power signal lines 29. The USB 20 supplies power from the host computer 30, and establishes a two-way communication link between the multiple technology data reader 10 and the host computer 30. As an alternative to the host computer 30 supplying power via the USB 20, or in addition thereto, an independent power source (not shown) may be included within the multiple technology data reader 10, either in the FIG. 1 embodiment or the other embodiments described later herein.

[0025] In operation, the device communications, control and power unit 16 receives data signals from the bar code reader 12 and the RFID readers 14aand 14b, and provides power to each of these readers. The device communications, control and power unit 16 may also be used to activate the bar code reader 12 and the RFID readers 14aand 14bindependently, simultaneously or concurrently.

[0026] FIG. 2 is a functional block diagram of a multiple technology data reader 10, which can read a bar code 72 or an RFID tag 74. The bar code 72 is read and detected by an optics means 42, which sends the detected signal to an analog front end means 52. The analog signal is then converted to a digital signal by a conversion to digital means 62. The converted digital signal is decoded by a bar code decoder 28a, and then sent to a host computer 30 via a USB 20.

[0027] The RFID tag 74 is detected by an antenna 44. The antenna transmits an electromagnetic signal 75 and detects a response signal 76 from the RFID tag 74. The response signal 76 is sent to an RFID transmitter/receiver 64 through an impedance matching network 54, which matches the impedance of the antenna 44 with the impedance of the RFID transmitter/receiver 64. The response signal 76 is then decoded by an RFID decoder 28b, and then sent to a host computer 30 via the USB 20.

[0028] FIG. 3 is a block diagram illustrating a preferred configuration of logical connections for a multiple technology data reader 10aaccording to one embodiment utilizing a compound interface between the data reading components and the host device. In FIG. 3, a multiple technology data reader 10aincludes an RFID reader 14, connected to one port of an internal hub 18, and a bar code reader 12, connected to another port of hub 18. The internal hub 18 is connected to a USB 20, which supplies power from a host computer 30 and establishes a two-way communication link between the compound multiple technology data reader 10aand the host computer. The RFID reader 14 and bar code reader 12 are logically addressable over the USB 20 via the internal hub 18. The multiple technology scanner 10ashown in FIG. 3 operates in a manner as described with regard to FIG. 1.

[0029] FIG. 4 is a block diagram illustrating a preferred configuration of logical connections for a multiple technology data reader 10baccording to another embodiment utilizing a composite or complex interface between the data reading components and the host device. In the FIG. 4 embodiment, the multiple technology data reader 10bincludes an RFID reader 14, and a bar code reader 12, both connected to a USB 20. The RFID reader 14 and bar code reader 12 are logically addressed without the use of an internal hub (such as used in the embodiment shown in FIG. 3). In the FIG. 4 embodiment, the USB 20 supplies power from a host computer 30 and establishes a two-way communication link between the composite multiple technology data reader 10band the host computer.

[0030] In a variation of the FIG. 4 embodiment, the multiple technology data reader 10buses a complex interface implementation that is based on human interface device (HID) report descriptors, and is specific to HID class USB devices (i.e. a keyboard, mouse, etc.). In all other respects, this variation operates in the same manner as the FIG. 4 embodiment as described above.

[0031] FIGS. 5-10 illustrate six alternative system architectures in accordance with a multiple technology data reader 10 such as shown in FIG. 1 and described herein. In a first embodiment, as shown in FIG. 5, the multiple technology data reader 100 includes a bar code reader subsystem 120, and an RFID reader sub-system 140, each serially connected to a device microcontroller 125. The device microcontroller 125 includes a device interface 126afor the bar code reader subsystem, and a device interface 126bfor the RFID reader subsystem, each of which is connected to a device communications, control and power unit 160. The multiple technology data reader 100 also includes a trigger unit 170, which sends and receives control signals and power, both to and from the device communications, control and power unit 160 on the device microcontroller 125. The device microcontroller 125 is connected to a host computer 130 via USB 150.

[0032] In the embodiment shown in FIG. 5, the reader device interfaces 126ahas an input/output endpoint zero 110a, which enables the host computer 130 to use a default control method to initialize and configure the reader device interface 126a. In addition, the reader device interface 126ahas an endpoint one 111, which allows the host computer 130 to send data to the reader device interface 126a, and an endpoint 112, which allows the reader device interface 126ato send data to the host computer 130. Furthermore, data can be sent in either direction between the reader device interface 126aand the barcode reader subsystem 120 via a serial communication line 105a.

[0033] In a similar manner, reader device interface 126bhas an input/output endpoint zero 110b, which enables the host computer to use a default control method to initialize and configure the reader device interface 126b. In addition, endpoint three 113 and endpoint four 114, respectively allow the host computer to send data to the reader device interface 126b, and the reader device interface 126bto send data to the host computer. Data can be sent in either direction between the reader device interface 126band the RFID reader subsystem 140 via the serial communication line 105b.

[0034] This first embodiment is an example of how the multiple technology data reader 300 may be readily implemented using off-the-shelf components.

[0035] In a second embodiment, as shown in FIG. 6, the multiple technology data reader 200 includes the optical and analog front end components of a bar code reader 220, and the antenna and transmitter/receiver components of an RFID reader 240, which are connected to a device microcontroller 225. The device microcontroller 225 includes a decoder and control unit 228afor the bar code reader, and another decoder and control unit 228bfor the RFID reader. The decoder and control units 228aand 228bare each connected to a device communications, control and power unit 260. The multiple technology data reader 200 also includes a trigger unit 270, which sends and receives control signals and power, both to and from the device communications, control and power unit 260 on the device microcontroller 225. The device microcontroller 225 is connected to a host computer 230 via USB 250.

[0036] In the embodiment shown in FIG. 6, the bar code decoder and control unit 228ahas the same endpoints as the reader device interface 126adescribed in FIG. 5. Likewise, the RFID decoder and control unit 228bhas the same endpoints as the reader device interface 126bdescribed in FIG. 5.

[0037] In a third embodiment, as shown in FIG. 7, the multiple technology data reader 300 includes the optical and analog front end components of a bar code reader 320, and the antenna and transmitter/receiver of an RFID reader 340, which are connected to a device microcontroller 325. The device microcontroller 325 includes a bar code pre-processor 322 and an RFID pre-processor 324, both of which are connected to a common decoding and control unit 328. The decoding and control unit 328 is connected to a device communications, control and power unit 360. The multiple technology data reader 300 also includes a trigger unit 370, which sends and receives control signals and power, both to and from the device communications, control and power unit 360 on the device microcontroller 325. The device microcontroller 325 is connected to a host computer 330 via USB 350.

[0038] In the embodiment shown in FIG. 7, the decoding and control unit 328 has an input/output endpoint zero 310, which enables the host computer to use a default control method to initialize and configure the decoding and control unit 328. In addition the decoding and control unit 328 has four additional endpoints, which enable data to be sent to and from the host computer 330.

[0039] By integrating the bar code pre-processor 322, the RFID pre-processor 324, and the decoding and control unit 328 into the device microcontroller 325, the manufacturing costs for the multiple technology data reader 300 may be reduced. Moreover, integration of these components enables optimal performance from the multiple technology data reader 300.

[0040] In a fourth embodiment, as shown in FIG. 8, the multiple technology data reader 800 includes a bar code reader sub-system 820, and an RFID reader sub-system 840, each serially connected to a bus add-on card 825. The bus add-on card 825 includes a device interface 826afor the bar code reader subsystem, and a device interface 826bfor the RFID reader subsystem, each of which is connected to a device communications, control and power unit 860. The multiple technology data reader 800 also includes a trigger unit 870, which sends and receives control signals and power, both to and from the device communications, control and power unit 860 on the bus add-on card 825. The bus add-on card 825 is connected to a host computer 830 via a computer bus 850. The computer bus 850 may be any one of a variety of computer buses, including parallel or serial buses.

[0041] In the embodiment shown in FIG. 8, the reader device interfaces 826ahas a controls input line 810a, which enables the host computer 830 to send control commands to the reader device interface 826a. In addition, the reader device interface 826ahas a data output line 812, which allows the reader device interface 826ato send data to the host computer 830. Furthermore, data can be sent in either direction between the reader device interface 826aand the barcode reader subsystem 820 via a serial communication line 805a.

[0042] In a similar manner, reader device interface 826bhas a controls line 810b, which enables the host computer 830 to send control commands to the reader device interface 826b. In addition, the reader device interface 826bhas a data line 812b, which allows the reader device interface 826bto send data to the host computer 830. Data can be sent in either direction between the reader device interface 126band the RFID reader subsystem 840 via the serial communication line 805b.

[0043] In a fifth embodiment, as shown in FIG. 9, the multiple technology data reader 900 includes the optical and analog front end components of a bar code reader 920, and the antenna and transmitter/receiver components of an RFID reader 940, which are connected to a device bus add-on card 925. The bus add-on card 925 includes a decoder and control unit 928afor the bar code reader, and another decoder and control unit 928bfor the RFID reader. The decoder and control units 928aand 928bare each connected to a device communications, control and power unit 960. The multiple technology data reader 900 also includes a trigger unit 970, which sends and receives control signals and power, both to and from the device communications, control and power unit 960 on the bus add-on card 925. The bus add-on card 925 is connected to a host computer 930 via a computer bus 950. The computer bus 950 may be any one of a variety of computer buses, including parallel or serial buses.

[0044] In the embodiment shown in FIG. 9, the bar code decoder and control unit 928ahas the same input and output lines as the reader device interface 826adescribed in FIG. 8. Likewise, the RFID decoder and control unit 228bhas the same input and output lines as the reader device interface 826bdescribed in FIG. 8.

[0045] In a sixth embodiment, as shown in FIG. 10, the multiple technology data reader 1000 includes the optical and analog front end components of a bar code reader 1020, and the antenna and transmitter/receiver of an RFID reader 1040, which are connected to a bus add-on card 925. The bus add-on card 925 includes a bar code pre-processor 1022 and an RFID pre-processor 1024, both of which are connected to a common decoding and control unit 1028. The decoding and control unit 1028 is connected to a device communications, control and power unit 1060. The multiple technology data reader 1000 also includes a trigger unit 1070, which sends and receives control signals and power, both to and from the device communications, control and power unit 1060 on the bus add-on card 925. The bus add-on card 925 is connected to a host computer 1030 via a computer bus 1050. The computer bus 1050 may be any one of a variety of computer buses, including parallel or serial buses.

[0046] In the embodiment shown in FIG. 10, the decoding and control unit 1028 has a controls input line 1010, which enables the host computer to send control commands to the decoding and control unit 1028. In addition the decoding and control unit 1028 has a data output line 1012, which enables data to be sent from the decoding and control unit 1028 to the host computer 1030.

[0047] In any of the embodiments depicted in FIGS. 5-7, the device communications, control and power unit 16 may be used to activate the bar code reader 12 and the RFID reader 14 independently, simultaneously or concurrently. In one embodiment, the device may be configured such that when a user pulls a trigger (not shown) on the outer body of the multiple technology data reader 10, one of the following actions is initiated: (1) the bar code reader 12 alone is activated; (2) the RFID reader 14 alone is activated; or (3) both the bar code reader 12 and the RFID reader 14 are activated.

[0048] Alternatively, when a user pulls the trigger located on the outer body of the multiple technology data reader 10, the bar code reader 12 is briefly activated to test for the presence of a bar code symbol. The presence of a bar code symbol may be indicated by the satisfaction of certain pre-set, user-defined criteria from among the following possible conditions: (a) presence of certain levels of reflected light (i.e. from laser, LED or ambient sources); or (b) presence of certain light modulation in response to printed symbols. If the test conditions are satisfied, then the bar code reader 12 remains activated until the trigger is released or a bar code is detected. Alternatively, if the test conditions are not satisfied, then the RFID reader 14 is activated for a pre-configured test or read operation.

[0049] In yet another alternative embodiment, the device may be configured such that when a user pulls the trigger located on the outer body of the multiple technology data reader 10, the RFID reader 14 is briefly activated to test for the presence of an RFID tag based on the following set of pre-defined, user specified criteria: (a) return signals are detected that appear to be from decodable radio tags; or (b) packets of data are received which match certain pre-selected protocols. If the test conditions are satisfied, then the RFID reader 14 remains activated until the trigger is released or an RFID tag is detected. Alternatively, if the test conditions are not satisfied, then the bar code reader 12 is activated for a pre-configured test or read operation.

[0050] In any of the embodiments depicted in FIGS. 5-7, the user may specify which type of RFID tags should be read, and which should be ignored. For example, it is well known by those in the art that read/write tags can send an identification code, via a response signal, with multiple fields. The user may specify that the RFID reader 14 remain activated only if certain fields of the identification code sent by the RFID tag match user-defined criteria.

[0051] In addition, the user can also specify that the RFID reader 14 remain activated only if it appears that there is a single RFID tag in the read area. For instance, if there are multiple RFID tags in the read area, each RFID tag will send a response signal back to the RFID reader 14. Generally, when this occurs there will be a collision between the multiple response signals. In this case, the user may specify that the RFID reader 14 be deactivated if such a collision is detected.

[0052] In the case where multiple RFID tags are detected by the RFID reader 14, there may be an ambiguity as to which RFID tag is being read. To solve this problem, both an RFID tag and a bar code label may be placed on items to be identified. Then to avoid reading the wrong RFID tag, or having to physically separate the RFID tags, bar code reader operation may be automatically invoked instead when two or more RFID tags are detected. By activating the bar code reader 12 automatically, the user is able to obtain more precise and accurate information.

[0053] One advantage of this method of combining two automatic identification technologies into a single device is that the user is assured that a more accurate and reliable method of data acquisition is being employed for the specific task being performed.

[0054] While embodiments and applications of the present invention have been shown and described, it will be apparent to one skilled in the art that other modifications, alternatives and variations are possible without departing from the inventive concepts set forth herein. Therefore, the invention is intended to embrace all such modifications, alternatives and variations that fall within the scope and spirit of the appended claims.