Abstract:
A multiwavelength barcode reader is used for reading a barcode, and transmitting the read barcode to a system composed of a pair of connected information devices. In the barcode reader, several sets of light sources having different wavelengths are disposed so as to enable the barcode reader to provide a light source having a suitable wavelength in accordance with a color of the barcode when reading or scanning the barcode, thereby improving the resolution of the read or scanned barcode.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to a multiwavelength barcode reader for reading a barcode, and more particularly to a barcode reader provided with light sources having two or more wavelengths and capable of improving the resolution of a read barcode. 
     2. Related Art 
       FIG. 1  is a schematic structural view of a conventional barcode reader. Referring to  FIG. 1 , a barcode reader  10  (also known as barcode scanner) mainly includes a light source module  101 , a driving unit  102 , an image capturing module  103 , a detection unit  104 , a translation module  105 , an transmission module  106 , and a switch  107 . The light source module  101  is formed by a plurality of light emitting diodes (LEDs), and electrically connected to the driving unit  102 . The driving unit  102  is electrically connected to the switch  107 , and after the switch  107  is turned on, the driving unit  102  is enabled to drive the light source module  101  to generate a light source. The image capturing module  103 , that is, a charge coupled device (CCD), is used for capturing an image, and is electrically connected to the detection unit  104  and the driving unit  102 . The detection unit  104  is used for detecting whether the image capturing module  103  successfully captures image data about the barcode, and is electrically connected to the driving unit  102 . If the image capturing module  103  fails to capture the image data about the barcode, the detection unit  104  enables the driving unit  102  to drive the light source module  101  and the image capturing module  103  again to read the barcode (by means of scanning or image capturing). When the driving unit  102  drives the light source module  101  to operate, the image capturing module  103  is also driven to capture an image of the barcode. The translation module  105  is used for decoding and recognizing the image data about the barcode captured by the image capturing module  103 , so as to convert the barcode symbol into information in the form of texts or figures. The transmission module  106  further connects the barcode reader  10  to an information device, such as a computer host, so as to transmit the decoded data to the information device connected thereto. The transmission module  106  has a transmission port as a connection end. The transmission port may be, for example, a USB (universal serial bus) transmission port, a PS/2 (Personal System/2) transmission port, or an RS232 (Electronic Industry Association-Recommended standard-232) transmission port. 
       FIG. 2  is a flow chart of a process of implementing the conventional barcode reader. Referring to  FIGS. 1 and 2 , the process includes the following steps. 
     Step  1 , turn on the switch  11 : a user presses down the switch  107  to start the barcode reader  10 . 
     Step  2 , turn on the light source  12 : the driving unit  102  actuates the light source module  101  and the image capturing module  103 , and the user aligns light generated by the light source module  101  with the barcode symbol to be captured. 
     Step  3 , capture an image of the barcode  13 : the image capturing module  103  captures an image of the barcode. 
     Step  4 , detect  14 : the detection unit  104  detects whether the image of the barcode is successfully captured, and if a detection result is “YES”, a translating operation is performed; if a detection result is “NG”, the image capturing module  103  continues to capture the barcode symbol. 
     Step  5 , translate  15 : the translation module  105  translates the captured image of the barcode, and converts the barcode symbol into information in the form of texts or figures. 
     Step  6 , transmit  16 : the transmission module  106  transmits the converted information to the information device. 
     In view of the above, in the implementation of the conventional barcode reader  10 , when light generated by the light source module  101  is irradiated on a barcode symbol, the image capturing module  103  captures an image of the barcode symbol, and the image of the barcode symbol is translated into data in the form of texts or figures. In practice, most products available at the market have their barcode symbols printed on the external package, and the barcode symbols are generally composed of black bars on a white background. However, to meet the requirement of a nice and consistent package of the products, other colors, for example, red, green, and blue, are used as barcode colors for the barcode symbols when printed on the external package of the products. As the existing barcode reader all provide a single red light source, if the scanned barcode has a background color close to red or has a low color contrast after being irradiated by a red light, the reading of the barcode reader may be affected. 
     SUMMARY OF THE INVENTION 
     In order to solve the above problem, the present invention is directed to a barcode reader capable of scanning or reading barcodes in different colors. 
     Accordingly, the barcode reader of the present invention mainly includes light source modules having two or more different wavelengths, and the light source modules are capable of generating light sources of different wavelengths (colors), for example, red and green light. When the scanner scans a barcode, the light source modules may separately or simultaneously irradiate light on the barcode to generate light sources of different wavelengths (colors), so that the barcode symbol can be clearly seen based on the principle of color contrast. Therefore, the resolution and read rate of the barcode are improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given herein below for illustration only, and thus are not limitative of the present invention, and wherein: 
         FIG. 1  is a schematic structural view of a conventional barcode reader; 
         FIG. 2  is a flow chart of a process of implementing the conventional barcode reader; 
         FIG. 3  is a schematic structural view of the present invention; 
         FIG. 4  is a flow chart of a process of implementing the present invention; 
         FIG. 5  shows a first preferred embodiment of the present invention; 
         FIG. 6  shows a second preferred embodiment of the present invention; and 
         FIG. 7  shows a third preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 3  is a schematic structural view of the present invention. Referring to  FIG. 3 , the multiwavelength barcode reader  20  of the present invention mainly includes a first light source module  201 , a driving unit  202 , a second light source module  203 , an image capturing module  204 , a detection unit  205 , a translation module  206 , a transmission module  207 , and a switch  208 . The driving unit  202  is electrically connected to the switch  208 , so that the On/Off of the driving unit  202  is controlled by the switch  208 . The driving unit  202  may be an on-chip microprocessor, and capable of managing a power source and actuating related electronic modules. The first light source module  201  and the second light source module  203  are respectively electrically connected to the driving unit  202 . The driving unit  202  may sequentially or simultaneously drive the first light source module  201  and the second light source module  203  to emit light. The light source modules  201 ,  203  are formed by LEDs or laser diodes. One of the light wavelength of the light source module ( 201  or  203 ) generates red, blue, or green light. The image capturing module  204  is electrically connected to the driving unit  202 , and driven by the driving unit  202  to capture an image of a barcode. The image capturing module  204  is a CCD (Charge Coupled Device). The detection unit  205 , capable of detecting a signal, is electrically connected between the image capturing module  204 , the driving unit  202 , and the translation module  206 , so as to detect whether the image capturing module  204  successfully captures the image of the barcode. On detecting a signal indicating that the image capturing module  204  fails to capture the image of the barcode, the detection unit  205  enables the driving unit  202  to drive the first light source module  201  or the second light source module  203  and the image capturing module  204  again. The translation module  206  is used for translating the image of the barcode captured by the image capturing module  204  into data in the form of texts or figures. The transmission module  207  is electrically connected to the translation module  206 , and used for transmitting the data translated by the translation module  206  to another information device. The transmission module  207  is further connected to a physical connection port. The physical connection port may be, for example, a USB (universal serial bus) transmission port, a PS/2 (Personal System/2) transmission port, or an RS232 (Electronic Industry Association-Recommended standard-232) transmission port. 
       FIG. 4  is a flow chart of a process of implementing the present invention. Referring to  FIGS. 3 and 4 , the multiwavelength barcode reader  20  of the present invention is actuated by a user, and the specific implementation is illustrated as follows: 
     Step  1 , turn on the switch  21 : the user presses down the switch  208  to start the multiwavelength barcode reader  20 . 
     Step  2 , turn on the first light source  22 : the driving unit  202  actuates the first light source module  201  to emit light, and the user enables the first light source module  201  to irradiate the emitted light on an image of the barcode to be read. 
     Step  3 , capture an image of the barcode  23 : the image capturing module  204  reads (or captures/scans) the image of the barcode. 
     Step  4 , detect  24 : the detection unit  205  detects whether the image capturing module  204  successfully reads the image of the barcode, and if yes, outputs a signal indicating “YES” to the translation module  206 ; otherwise, outputs a signal indicating “NG” to the driving unit  202 . 
     Step  4 - 1 , turn on the second light source  241 : on receiving the “NG” signal for a first time in the previous step, the driving unit  202  drives the second light source module  203  to emit light. At this point, the light source generated by the first light source module  201  is turned off, and Steps  3  and  4  are performed. When detecting that the image capturing module  204  fails to read the image of the barcode for a second time, the detection unit  205  again outputs a signal indicating “NG” to the driving unit  202 . 
     Step  4 - 2 , turn on the second light source for a second time  242 : on receiving the “NG” signal for a second time in the previous step, the driving unit  202  again drives the second light source module  203  to emit light, and Steps  2  to  4  are performed. At this point, the first light source module  201  and the second light source module  203  are both turned on to obtain a light blending effect. The image capturing module  204  again reads the image of the barcode, and if the reading is still unsuccessful, Steps  2  to  4 - 2  are repeatedly performed. 
     Step  5 , translate  25 : after the image capturing module  204  successfully reads the image of the barcode, the translation module  206  translates the read image of the barcode into data in the form of texts or figures. 
     Step  6 , transmit  26 : the transmission module  207  outputs the translated data in the form of texts or figures via a transmission port to a corresponding information device, for example, a computer host or a terminal of the barcode reader. 
     In view of the above, in the multiwavelength barcode reader of the present invention, light source modules having different wavelengths are disposed to provide light sources of different wavelengths when reading an image of a barcode, so as to meet the requirement of reading color barcodes. The light source modules may be sequentially, separately, or simultaneously turned on. When the light sources of different wavelengths are automatically turned on one after another, the barcodes of different colors can be read. When the light sources of different wavelengths are turned on at the same time, a light blending effect is obtained, which may improve the read rate of the image of the barcode, i.e., the resolution of the barcode, in spite of a color barcode. Moreover, each light source module is directly driven by the driving unit, and the user only needs to turn on the switch to actuate an automatic reading process. In the reading process, the light source modules are directly switched between the modes of being sequentially or simultaneously turned on by the driving unit, so as to improve the practical applicability and the resolution of the barcode reader. 
       FIG. 5  shows a first preferred embodiment of the present invention. Referring to  FIGS. 3 and 5 , the first light source module  201  and the second light source module  203  may be physically disposed in a reading pane  209  of the multiwavelength barcode reader  20 , and are longitudinally arranged.  FIG. 6  shows a second preferred embodiment of the present invention. Referring to  FIG. 6 , the first light source module  201  and the second light source module  203  are longitudinally arranged close to each other.  FIG. 7  shows a third preferred embodiment of the present invention. Referring to  FIG. 7 , the first light source module  201  and the second light source module  203  are laterally arranged in an alternating manner. Moreover, the light source modules have different wavelengths, so as to generate light in different colors. For example, the first light source module  201  generates red light, and the second light source module  203  generates blue light. When the two light source modules operate at the same time, a light blending effect is obtained, and a light source of a third wavelength is generated. Thereby, even if a color image of the barcode is read, the multiwavelength barcode reader  20  also achieves a preferred read rate. Further, in the multiwavelength barcode reader of the present invention, a third light source module of another wavelength is disposed, for example, to generate green light. As such, the first light source module, the second light source module, and the third light source module may be LED chips having different wavelengths, for example, R, G, B chips, disposed on a circuit board. The LED chips are controlled by voltage or current to be turned on sequentially or simultaneously, thereby achieving the aforementioned efficacies of the present invention. 
     As described above, in the implementation of the multiwavelength barcode reader of the present invention, the color of the light emitted in reading is varied in accordance with different colors of a color image of the barcode, so that the resolution and practical applicability of the barcode reader are improved. Therefore, a barcode reader capable of scanning or reading barcodes of different colors is achieved. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.