Abstract:
An optical barcode and/or RFID reader having at least two sets of illuminating LEDs that are directed toward a target object to reflect whether the barcode and/or RFID reading was successful or unsuccessful. The reader is provided with a set of red LEDs and a set of green LEDs for illuminating targets, such as barcodes or RFID tags. In addition to using these LEDs to illuminate the target, the reader will illuminate the target with a particular color of light to signify a successful read, such green light, or an unsuccessful read, such as red light. A third color may be provided to indicate a successful RFID interrogation, such as blue light. The reader thus uses the built-in illumination LEDs to cast differently colored light on the target, rather than having to provide additional LEDs in a user interface positioned on the housing of the reader.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to autoidentification systems and, more particularly, to a system and method for providing user feedback using target illumination sources. 
     2. Description of the Related Art 
     Autoidentification systems, such as optical imagers and radiofrequency identification (RFID) readers are being used with increasing frequency for a variety of applications, including obtaining medical information or medical data from patients and medication contains, verifying the contents of patient medical samples, or extracting information from labeled products, such as shipping containers or retail items that contain barcodes or RFID tags. 
     Barcodes are essentially graphic representation of data (alpha, numeric, or both) that is machine-readable. Barcodes encode numbers and letters into different types of symbologies, such as linear codes, two-dimensional codes, and composite codes (a combination of linear and two-dimensional codes). In more recent applications, referred to as digital or optical image capture, an optical device snaps a digital picture of the barcode and software in the imager orients the picture and decodes the barcode(s) contained in the picture. 
     Radiofrequency identification (RFID) is a wireless communication technology that utilizes radiowaves for automatic identification and data capture of information for the purpose of identifying and tracking objects or people. Signals in the radio frequency (RF) range of the electromagnetic spectrum are used to communicate data between a two transceiver devices. An RFID system typically consists of the three main components: a tag, a reader, and the software/firmware for controlling the system. Tags are placed on objects or people and directly or indirectly contain information about the object or person. The reader uses RF energy to interrogate the tag and read the information it contains, or even write data to the tag. 
     Technologies such as barcode imaging and RFID can play an important role in various fields by automating processes and improving safety and security. For example, the ability to more accurately track objects and instantly provide data about the object is becoming a particularly important tool in the medical field, where automated systems can help improve safety procedures and limit human errors. In one such system, medical samples and prescription medication may often be provided with a barcode to assist with tracking the formulation and delivery of the medication or samples, and proper identification of the patient to whom the medication or samples belong. RFID technology may be used for tracking medical devices to ensure that the right device is available to the correct patient at the correct time, or to track the location of high-risk devices like implants that may relocate within a patient. 
     Although conventional barcode readers may include on-board illumination sources, such as light-emitting diodes (LEDs) for enhancing the visibility of the target, barcode readers and RFID systems rely on other LEDs to indicate the status of autoidentification processes. For example, the housing for the barcode or RFID reader may include LEDs aligned to indicate to the user a successful barcode interpretation or RFID interrogation. In addition to increasing the cost and complexity of such systems, the use of status LEDs is cumbersome as the user must try to perceive the target barcode or RFID tag and consider the special LEDs at the same, which may not be easily viewed or even in the proximity of the user. 
     BRIEF SUMMARY OF THE INVENTION 
     It is therefore a principal object and advantage of the present invention to provide a system and method for providing feedback to a user that is cost effective. 
     It is an additional object and advantage of the present invention to provide a system and method for providing feedback to a user that is more easily perceived. 
     It is a further object and advantage of the present invention to provide a system and method for providing feedback to a user that is simple to implement. 
     In accordance with the foregoing objects and advantages, the present invention provides the use of the existing illumination system of a handheld or stand-mounted optical imager, or a combined optical imager and radiofrequency identification (RFID) reader, to reflect the status of operations to the user, i.e., whether the barcode and/or RFID reading was successful or unsuccessful. A barcode or RFID device is provided with at least two sets of illuminating LEDs that are directed toward a target object. Preferably, red LEDs are used for illuminating barcodes and a second set of LEDs, such as green, may also be provided for enhanced illumination. In addition to using these LEDs to illuminate the target, the present invention illuminates the target with a particular color of light to signify a successful read, such as green light, or an unsuccessful read, such as red light. A third color may be provided to indicate a successful RFID interrogation, such as blue light. The present invention thus uses the built-in illumination LEDs to cast differently colored light on the target, rather than having to provide additional LEDs in a user interface positioned on the housing of the reader. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of an optical imaging and RFID reader having multicolored illumination sources according to the present invention 
         FIG. 2  is a schematic of the electronics in an optical imaging and RFID reader having multicolored illumination sources according to the present invention. 
         FIG. 3  is a schematic of an alternative embodiment of a separate illumination source according to the present invention. 
         FIG. 4  is a flowchart of a process of controlling a multicolored illumination source according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, wherein like reference numerals refer to like parts throughout, there is seen in  FIG. 1  a optical imaging and RFID interrogation reader  10 . It should be recognized by those of skill in the art that the present invention may be used in combination with either a barcode reader or an RFID reader, or both and unit  10  is described as having both readers for illustrative purposes only. 
     Reader  10  generally comprises a microcontroller  12  that interconnects a first optical imager  14  and/or an RFID unit  16  to a host interface  18 . Alternatively, reader  10  is capable of interconnecting any variety of data capturing devices as submodules and providing host controllability, including optical imagers, RFID transceivers, lasers, scales, thermometers or temperature probes, etc., in any variety of combinations. Reader  10  may be arranged on a single printed circuit board  22  and encased as a single unit or housing. Integration of imager  14  and RFID unit  16  through interface  18  allows for combining control of operation of both submodules, such as RFID reading and barcode, through reader  10 , as will be explained in detail hereinafter. 
     Referring to  FIG. 2 , optical imager  14  comprises an image engine  20  having image processing circuitry interconnected to microcontroller  12  for omni-directional optical scanning. Image engine  20  controls an image sensor  24 , such as a complementary metal oxide semiconductor (CMOS) image sensor, and is capable of capturing two-dimensional images of 1D linear barcodes, 2D stacked/matrix barcodes, standard optical character recognition (OCR) fonts, Reduced Space Symbology (RSS) barcodes, and postal barcodes, as well as providing image captured images for use in a wide range of applications, such as image and shape recognition, signature capture, image capture, and non-standard optical character recognition. 
     Imager  14  may comprise, but is not limited to, an IT4X10/80 SR/SF or IT5X10/80 series imager available from Hand Held Products, Inc. of Skaneateles Falls, N.Y. that is capable of scanning and decoding most standard barcodes including linear, stacked linear, matrix, OCR, and postal codes. Specifically, the IT5X10/80 series imager is a CMOS-based decoded output engines that can read 2D codes, and has image capture capabilities sufficient for use with module  10 . Imager  14  obtains an optical image of the field of view and, using preprogrammed algorithms in image engine  20 , deciphers the context of the image to determine the presence of any decodable barcodes, linear codes, matrix codes, and the like. Image engine  20  may be programmed to perform other image processing algorithms on the image captured by imager  14 , such as shape recognition, match filtering, and other high-level processing techniques. Alternatively, a captured image may be processed by microprocessor  12 , albeit with a decreased level of performance due to the additional communication time needed to transfer images from image engine  20  to microprocessor  12 . 
     Reader  10  may comprise RFID unit  16  including an RFID transceiver  30  and associated RFID antenna  32  supporting standard RFID protocols, such as the TI Tag-it transponder protocol or ISO 15693. For these protocols, transceiver  30  operates at 13.56 MHz, and may comprise a S6700 Multi-Protocol Transceiver IC available from Texas Instruments of Dallas, Tex. Depending on the application, other frequency transceivers may be more appropriate based on target range, power availability, cost, etc. RFID unit  16  may further include a speaker or LED (not shown) for audibly indicating a successful interrogation of an RFID tag. 
     Antenna  32  is preferably a loop antenna of various sizes and turns implemented on a printed circuit board and connected to module  10 , or a wire loop installed antenna installed directly onto module  10 . Antenna  32  may be positioned remotely, thereby reducing the footprint of module  10  using an external connector, such as a MMCX coaxial connector. RFID transceiver  30  may be programmed to interrogate passive or active tags, process signals received from such tags (e.g., analog to digital conversion), and provide the information from the tags to microcontroller  12  for further processing or transmittal to a host computer via interface  18 . 
     Host interface  18  comprises a host transceiver  34  and a host connector  36  for interconnection to a host device  38 . Interface  18  may comprise a conventional RS232 transceiver and associated  12  pin RJ style jack. For example, an ADM202EARN available from Analog Devices, Inc. of Norwood, Mass. is a suitable RS-232/V.28 interface device having compliant levels of electromagnetic emissions and immunity. Alternatively, interface  18  may comprise other conventional buses, such as USB, IEEE 1394, I2C, SPI, or PCMCIA, or other connector styles, such as an FFC style to an embedded host or another module  10 . Interface  18  may also comprise a wireless transceiver in lieu of connector  36  for wireless communication to a host computer. A Stewart Connector Systems Inc. SS-641010S-A-NF may serve as connector  36  for mating with a Stewart Connector 937-SP-361010-031 matching connector of a host device. Host interface  18  may also comprise a Molex MX52588 connector. Regardless of the type of connector  36  used, host transceiver  34  is programmed with the applicable protocols for interfacing with a host computer, such as USB, Bluetooth(r), and IrDA protocols. Transceiver  34  may also be programmed to support both non-inverted signal sense and inverted signal sense. 
     Microcontroller  12  comprises a conventional programmable microprocessor having on-chip peripherals, such as central processing unit, Flash EEPROM, RAM, asynchronous serial communications interface modules, serial peripheral interfaces, Inter-IC Buses, timer modules, pulse modulators with fault protection modules, pulse width modulators, analog-to-digital converters, and digital-to-analog converters. Additionally, the inclusion of a PLL circuit allows power consumption and performance to be adjusted to suit operational requirements. In addition to the I/O ports dedicated I/O port bits may be provided. Microcontroller  12  may further include an on-chip bandgap based voltage regulator that generates an internal digital supply voltage from an external supply range. Microcontroller  12  preferably comprises a Motorola MC9S12E128. 
     The functional integration of imager  14  and RFID unit  16  to interface  18  is accomplished by microcontroller  12 , which receives and interprets host commands, and then executes the appropriate functions by driving imager  14  and/or RFID unit  16  accordingly. For example, the operation of imager  14  and RFID unit  16  may be triggered by serial commands sent to module  10  from a host device  38 , or by a hardware button communicating directly with connector  36  or through host device  38 . Microcontroller  12  may further be programmed to execute the functions otherwise performed by one or more of image engine  20 , RFID transceiver  30 , and host transceiver  34 , thereby reducing the amount of circuitry and hardware required by reader  10 . 
     As seen in  FIGS. 2 and 3 , reader  10  further includes an illumination source  26 , such as one or more light-emitting diodes (LEDs)  40  of various wavelengths, i.e., colors. For example, as seen in  FIG. 2 , illumination source  26  may be provided as part of imager  14 . In another embodiment of the present invention, illumination source  26  may be external to imager  14 , such as on a separate circuit board as seen in  FIG. 3 . It should be recognized by those of skill in the art that illumination source  26  may internal to imager  14 , external to imager  14  or reader  10 , or provided as part of another component, such as RFID antenna circuit board  22  as seen in  FIG. 3 , or any combination thereof. In any case, illumination source  26  should include at least two different color LEDs  40 , such as green and red. In another embodiment of the invention, illumination source  26  may include LEDs  40  of additional colors, such as blue. Illumination source  26  is preferably positioned to bathe a target, such as a barcode or RFID tag, with light to allow a user to more accurately direct reader  10  onto the target or properly illuminate the target for subsequent image capturing operations. As will be described hereinafter, illumination source  26  additionally provides feedback to the user on the status of the reading or interrogation operation. 
     Referring to  FIG. 4 , reader  10  implements a feedback process  42  to indicate to a user whether the target, whether a barcode or RFID tag, has been successfully decoded or interrogated, once reader  10  has been directed at the target and the user triggers imaging or interrogation of the target. Process  42  begins with reader  10  receiving a trigger command  44  to read or interrogate a target. The command is interpreted  46  to determine whether it involves barcode decoding, RFID interrogation, or both. If barcode reading has been commanded, imager  14  is activated  48  to capture an image of the target. If RFID has instead or additionally been commanded, RFID unit  16  is activated  50  to interrogate any RFID tag in proximity to reader  10 . In either case, a check is performed  52  to determine whether the barcode read or tag interrogation was successful. If so, illumination source  26  is activated  54  to illuminate the target with a predetermined color of lights, such as green. If not, illumination source  26  is activated  56  to illuminate the target with a different predetermined color of light, such as red, and control returns to the beginning. Illumination source  26  may optionally be activated to provide one predetermined color for successful barcode reading, such as green, and a different predetermined color for a successful RFID interrogation, such as blue. Thus, no additional user indicators are needed to reflect status to the user, and the user does not need to divert attention away from the target to confirm reading or interrogation status. This aspect of the present invention is particularly useful in situations where it is not feasible to present separate status indicators, such as in connection with legacy medical devices, or where the user otherwise would need to move or turn away from the work area to confirm the status of operations, thereby reducing productivity and increasing the risk for error.