FIELD OF THE INVENTION 
       [0001]    The present invention relates to a bill receiver with a foreign matter detection device, and more particularly to a bill receiver that uses a plurality of detection plates for detecting foreign matters. 
       BACKGROUND OF THE INVENTION 
       [0002]    As electronic technology advances and labor cost rises, more and more jobs are performed by automatic machines such as vending machines and money changing machines. Originally, automatic machines are used mainly for coins with a lower dollar amount, and characteristics including volume, density and conductivity are used for identifying real coins. As automatic machines are used for transactions of a higher dollar amount, dollar bills become an item that automatic machines must be able to handle and process. 
         [0003]    Traditionally, an automatic machine usually installs an anti-counterfeit machine to receive an inputted dollar bill, and a general anti-counterfeit machine uses a roller to read dollar bills. Once a dollar bill is put into the slot of an anti-counterfeit machine, the light at the opening of the slot will be blocked to start a main roller. After the dollar bill enters into the anti-counterfeit machine, an optical sensor will start operating. Each sensor has light emitting diodes capable of emitting infrared lights and visible lights with different wavelengths, and being a photo transistor used as a receiver, so that the reflectance ratio, transmission ratio and fluorescence of different portions of the dollar bill can be detected. Since dollar bills of different face values have their own characteristics, the anti-counterfeit machine can determine the face value of the dollar bill based on these characteristics. 
         [0004]    The main reason of using vending machines for selling merchandise resides on saving the labor force, and thus these machines can be used a substitute of labor force. If the vending machines are situated at a place with less customers or at an off-peak time, unauthorized persons may use special tools to draw the dollar bills out from the anti-counterfeit machine or take away the dollar bills from a bill storage container of the automatic machines. Therefore, automatic machines often come with a design that prevents unauthorized people to draw back the dollar bills as shown in  FIG. 1 . 
         [0005]    Referring to  FIG. 1  for a schematic view of a conventional anti-counterfeit machine, the dollar bill  11  is passed through a bill input inlet of the anti-counterfeit machine first, and then passed through a track  12 . To prevent the dollar bill  11  from being drawn out, the track  12  is generally designed with a curved shape, such as the track  13 , and then the dollar bill  11  is checked by an optical recognition device  14  to identify the dollar bill  11 . If the dollar bill  11  is determined to be a real dollar note, then the dollar bill  11  will be put into a bill container  15 . If the dollar bill  11  is determined to be a counterfeit, then the dollar bill  11  will be returned from another bill output outlet or the original bill input inlet. 
         [0006]    Generally, a curved track is designed to prevent the dollar bills from being drawn out, but such design can be cracked easily. For example, a string can be stuck onto a real dollar bill when the dollar bill is put into the inlet, and then another counterfeit is put into the inlet, so that when the anti-counterfeit machine returns the counterfeit, the string can be used to draw out the real dollar bill. As a result, the anti-counterfeit machine has a count of one dollar bill, but actually it has not received the dollar bill into the account. If a thief asks for a return of the dollar bill, the anti-counterfeit machine will return a dollar bill, and thus it will cause losses to a bank or a related party. 
         [0007]    Referring to  FIG. 2  for a schematic view of the structure of a conventional anti-drawing device, the anti-drawing device  20  comprises a main roller  21 , a secondary roller  22 , two support plates  25 ,  26 , an arc guide plate  23  and a protecting plate  24 . Two support plates  25 ,  26  are installed at both ends of the main roller  21  and the secondary roller  22 , and the main roller  21  and the secondary roller  22  are rotated in opposite directions under the support of the support plates  25 ,  26 , and a bill channel is disposed between the main roller  21  and the secondary roller  22 . The main roller  21  is comprised of a plurality of circular plates  27 , and a protruding object  28  is extended from a portion of the external surface of each circular plate  27  for winding a string that is entered into a bill input inlet together with the dollar bill  11 . A guide plate  23  is situated at the rear of the main roller  21 , and a bill channel is formed between the guide plate  23  and the main roller  21 . 
         [0008]    In view of the foregoing shortcomings of the prior art that cannot actively detect whether or not a string is entered, the inventor of the present invention based on years of experience from conducting research and experiments in the area of foreign matter detection finally invents a bill receiver with a foreign matter detection device to overcome the foregoing shortcomings. 
       SUMMARY OF THE INVENTION 
       [0009]    Therefore, it is a primary objective of the present invention to provide a bill receiver with a foreign matter detection device, and the bill receiver uses a plurality of detection plates for detecting foreign matters. 
         [0010]    To achieve the foregoing objective, the present invention discloses a bill receiver with a foreign matter detection device, comprising an upper base, a lower base, a holder and a detection device. The upper base has a plurality of first seams, and a bill channel is formed between the lower base and the upper base, and the lower base has a plurality of second seams corresponding to the positions of the first seams. The holder is installed in the lower base and has a plurality of detection plates and a control device. The detection plates are installed at an end of the holder, and the position of each detection plate corresponds to one of the positions of the first seam and one of the positions of the second seams. The control device is fixed at another end of the holder, such that the holder is contractible and displaceable in the lower base, and the detection plate is passed through the first seam and the second seam. The detection device is provided for detecting the position of the holder to determine whether or not a foreign matter exists in the bill channel. 
         [0011]    Since one of the beneficial effects of the bill receiver with a foreign matter detection device in accordance with the present invention is to detect a tiny foreign matter such as a 0.6 mm string, the invention can achieve the anti-theft effect. 
         [0012]    To make it easier for our examiner to understand the objective of the invention, its structure, innovative features, and performance, we use a preferred embodiment together with the attached drawings for the detailed description of the invention. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a schematic view of a conventional anti-counterfeit machine; 
           [0014]      FIG. 2  is a schematic view of a conventional anti-drawing device; 
           [0015]      FIG. 3  is a cross-sectional view of a bill receiver with a foreign matter detection device of the present invention; 
           [0016]      FIG. 4  is another cross-sectional view of a bill receiver with a foreign matter detection device of the present invention; 
           [0017]      FIG. 5  is a schematic view of a control device of the present invention; 
           [0018]      FIG. 6  is a schematic view of a detection device of the present invention; 
           [0019]      FIG. 7  is a schematic view of another detection device of the present invention; and 
           [0020]      FIG. 8  is a cross-sectional view of another bill receiver with a foreign matter detection device of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    The objectives, characteristics and advantages of the present invention will be described in more detail hereinafter with reference to related drawings that show various embodiments of the bill receiver of the invention. In the following figures, the same numerals are used to label the same respective elements for the illustration purpose. 
         [0022]    Referring to  FIG. 3  for a cross-sectional view of a bill receiver with a foreign matter detection device in accordance with the present invention and the bill receiver with a foreign matter detection device  30  is operated for the detection, the bill receiver  30  comprises an upper base  31 , a lower base  32 , a holder  33  and a detection device  34 . The upper base  31  has a plurality of first seams  311 , and a bill channel  35  is formed between the lower base  32  and the upper base  31 , and the lower base  32  has a plurality of second seams  321  corresponding to the position of the first seams  311 . The holder  33  is installed in the lower base  32 , and the holder  33  has a plurality of detection plates  331  and a control device  332 , and the detection plates  331  are installed at an end of the holder  33 , and the position of each detection plate  331  corresponds to one of the positions of the first seams  311  and one of the positions of the second seams  321 . The control device  332  is fixed at another end of the holder  33 , such that the holder  33  is contractible and displaceable in the lower base  32 , and the detection plate  331  is passed through the second seam  321 , the bill channel  35  and the first seam  311 . The detection device  34  is provided for detecting the position of the holder  33  to determine whether or not a foreign matter exists in the bill channel  35 . 
         [0023]    Referring to  FIG. 4  for a cross-sectional view of a bill receiver with a foreign matter detection device in accordance with the present invention when the bill receiver with a foreign matter detection device  30  is not operated yet, the bill receiver  30  comprises an upper base  31 , a lower base  32 , a holder  33  and a detection device  34 . The upper base  31  has a plurality of first seams  311 , and a bill channel  35  is formed between the lower base  32  and the upper base  31 , and the lower base  32  has a plurality of second seams  321  corresponding to the first seams  311 . The holder  33  is installed in the lower base  32 , and the holder  33  has a plurality of detection plates  331  and a control device  332 , and the detection plates  331  are installed at an end of the holder  33 , and the position of each detection plate  331  corresponds to one of the positions of the first seams  311  and one of the positions of the second seams  321 . The control device  332  is fixed at another end of the holder  33 , such that the holder  33  is contractible and displaceable in the lower base  32 . If the bill receiver is not operated, the end of the detection plate  331  will be passed precisely through the second seam  321  and situated at the same horizontal plane with the external surface of the lower base  32 , such that the bill channel  35  allows the dollar bill to be passed through successfully 
         [0024]    Referring to  FIG. 5  for a schematic view of a control device of the present invention, the control device  332  further comprises a resilient element  41  and an electromagnetic element  42 . The electromagnetic element  42  is provided for producing a magnetic force to attract the holder  33  to move the holder  33  close to the electromagnetic element  42 . If the electromagnetic element  42  does not produce the magnetic force, the resilience of the resilient element  41  moves the holder  33  away from the electromagnetic element  42 . 
         [0025]    Referring to  FIG. 6  for a schematic view of a detection device of the present invention, the detection device  34  further comprises a light emitting device  51 , a light receiver  52  and a slab  53 . The slab  53  is fixed on the holder  33 , and the slab  53  has an aperture  531 , such that if the slab  53  is moved together with the holder  33  to a predetermined position, the light receiver  52  can receive a light beam transmitted from the light emitting device  51  through the aperture  531 , and the light can be used for determining whether or not a foreign matter exists in the bill channel  35 . If the light receiver  52  cannot receive the light beam transmitted from the light emitting device  51  through the aperture  531 , it is determined that a foreign matter exists in the bill channel  35 . 
         [0026]    Referring to  FIG. 7  for a schematic view of another detection device of the present invention, the detection device  34  is a rotation sensor  61  connected to the holder  33  for producing a rotation angle based on the displacement of the holder  33 . If the rotation sensor  61  returns to the rotation angle, it will be determined that no foreign matter exists in the bill channel  35 . If the rotation sensor  61  has not returned to the rotation angle, it will be determined that a foreign matter exists in the bill channel  35 . 
         [0027]    Referring to  FIG. 8  for a cross-sectional view of another bill receiver with a foreign matter detection device of the present invention, the bill receiver  30  with a foreign matter detection device comprises an upper base  31 , a lower base  32 , a holder  33 , a detection device  34  and a bill transmission device  71 . The upper base  31  has a plurality of first seams  311 , and a bill channel  35  is formed between the lower base  32  and the upper base  31 , and the lower base  32  has a plurality of second seams  321  corresponding to the positions of the first seams  311 . The holder  33  is installed in the lower base  32 , and the holder  33  has a plurality of detection plates  331  and a control device  332 . The detection plates  331  are installed at an end of the holder  33 , and the position of each detection plate  331  corresponds to one of the positions of the first seams  311  and one of the positions of the second seams  321 . The control device  332  is fixed to another end of the holder  33 , such that the holder  33  is contractible and displaceable in the lower base  32 , and the detection plate  331  passes through the second seam  321 , the bill channel  35  and the first seam  311 . A bill transmission device  71  is provided for detecting the number of rotations of a conveying roller  72  in the bill channel  35  to determine whether or not a dollar bill has passed through the positions of the first seam  311  and the second seam  321 . The detection device  34  is provided for detecting the position of the holder  33  to determine whether or not a foreign matter exists in the bill channel  35 . 
         [0028]    While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.
A bill receiver with foreign matter detection device is disclosed. The bill receiver is that an upper base and a lower base, which are formed to be a bill channel, have a plurality of seams corresponding to each other. A holder is disposed under the lower base. A plurality of detection plates disposed upon the holder corresponds to the plurality of seams of the upper and the lower bases. The holder has flexible displacements through a control device. The detection plates then pass through the seams. It then determines whether or not the bill channel has foreign matters through the position of the holder detected by a detection device.