Abstract:
A bill dispenser is disclosed to include an optical transmitter module and an optical receiver module for measuring the transmittance of the bill being dispensed toward the bill outlet, and a control circuit for comparing the transmittance measured by the optical receiver module with a reference value and controlling the operation of the dispensing roller set of the bill dispenser subject to the comparison result, assuring accurate dispensing of one single bill at a time.

Description:
[0001]     This application is a Continuation-In-Part of my patent application Ser. No. 11/161,893, filed on Aug. 22, 2005. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to bill dispensers and more particularly, to such a single-bill output control of a bill dispenser, which dispenses only one single bill at a time.  
         [0004]     2. Description of the Related Art  
         [0005]     Following fast development of modern technology, our mode of living has been changed. Various automatic vending machines (ticket venders, coin exchanging machines, etc.) are used everywhere to sell different products without serviceman. These automatic vending machines save much labor and bring convenience to people. An automatic vending machine may be quipped with a bill dispenser to dispense bills (cards, tickets, coupons, banknotes, etc.). However, due to thin thickness of bills, bills may be not smoothly dispensed, or two or more bills may be overlapped and delivered to the bill outlet at a time. Manufacturers are trying hard to design bill dispensers that can dispense bills smoothly and individually.  
         [0006]      FIG. 8  is a schematic side view of a bill dispenser according to the prior art. As illustrated, the bill dispenser A comprises an accommodation chamber A 1 , a gap adjustment device B disposed at the front side of the accommodation chamber A 1 , a plurality of sheet transferring rollers A 2  disposed at the bottom side of the accommodation chamber A 1 , a motor A 3  controlled to rotate the sheet transferring rollers A 2  and to transfer bills C out of the accommodation chamber A 1  to the bill path controlled by the gap adjustment device B. According to this design, the circumferential length of the sheet transferring rollers A 2  is shorter than the length of the bills C, and the sheet transferring rollers A 2  are molded from a material having a high friction force, for example, rubber. Therefore, the sheet transferring rollers A 2  keep transferring bills C forwards when rotated. To control dispensing of one single bill C at a time, the ratio between the circumferential length of the sheet transferring rollers A 2  and the length of the bills C must be measured. However, this limitation does not allow the bill dispenser to dispense different sizes of bills C. Further, the sheet transferring roller A 2  transfer bills C by means of a friction force. However, due to precision reason, the gap adjustment device B may no adjust a gap of the bill path to fit the thickness of one single bill C precisely. In this case, two overlapped or stacked bills C may be dispensed. If the gap of the gap adjustment device B allows only one single bill C to pass, follow-up bills C may be jammed in the gap adjustment device B or in between the gap adjustment device B and the accommodation chamber A 1 , resulting in failure in functioning of the bill dispenser A.  
         [0007]     Therefore, it is desirable to provide an individual bill output control method for bill dispenser that eliminates the aforesaid problems.  
       SUMMARY OF THE INVENTION  
       [0008]     The present invention has been accomplished under the circumstances in view. It is therefore the main object of the present invention to provide a bill dispenser, which dispenses one single bill accurately at a time.  
         [0009]     To achieve this and other objects of the present invention, the bill dispenser comprises a housing, which comprises a frameboard, a bill chamber defined above the frameboard, an accommodation chamber defined below the frameboard, a bill outlet in the front side, a bill passage in communication between the bill chamber and the bill outlet, a bill-empty sensor mounted in the frameboard and adapted for providing a bill-empty signal when the bill chamber is empty, a transferring roller set mounted in the accommodation chamber and adapted for transferring bills out of the bill chambers toward the bill passage, a dispensing roller set mounted in the bill chamber between the frameboard and the bill passage and adapted for dispensing bills been transferred by the transfer roller set, an optical transmitter module adapted for transmitting a light across the bill passage when the dispenser roller set is dispensing a bill through the bill passage toward the bill outlet, an optical receiver module adapted for receiving the light that is transmitted by the optical transmitter module and passing through the bill being dispensed through the bill passage toward the bill outlet by the dispensing roller set and outputting an output signal indicative of the intensity of the light received, and a control circuit adapted for receiving the output signal of the optical receiver module and comparing the output signal of the optical receiver module with a predetermined reference value and controlling the operation of the dispensing roller set and the transferring roller set subject to the comparison result. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is an elevational view of a bill dispenser according to the present invention.  
         [0011]      FIG. 2  is an exploded view of the bill dispenser according to the present invention.  
         [0012]      FIG. 3  is a schematic side view in an enlarged scale of a part of the bill dispenser according to the present invention.  
         [0013]      FIG. 4  is a circuit diagram of the control circuit of the bill dispenser according to the present invention.  
         [0014]      FIG. 5  is a schematic sectional side view of the bill dispenser before dispensing of a bill.  
         [0015]      FIG. 6  is similar to  FIG. 5  but showing a bill dispensed to the bill outlet.  
         [0016]      FIG. 7  is an operation flow chart of the present invention.  
         [0017]      FIG. 8  is a schematic side view of a bill dispenser according to the prior art. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0018]     Referring to  FIGS. 1-3 , a bill dispenser is shown comprising a housing  1 , an optical receiver module  2  and an optical transmitter module  3 .  
         [0019]     The housing  1  is comprised of a bottom shell  101 , two side panels  102  and a top cover  103 . The housing  1  houses a frameboard  11 . The frameboard  11  has a plurality of slots  111  cut through the top and bottom walls thereof, and two upright locating plates  112  symmetrically disposed at two opposite sides. The housing  1  defines a bill outlet  15  in the front side, a bill chamber  12  above the frameboard  11  for accommodating a number of bills of one single denomination, an accommodation chamber  13  below the frameboard  11 , and a bill passage  14  in communication between the bill chamber  12  and the bill outlet  15  for guiding one single bill out of the bill chamber  12  to the bill outlet  15  at a time. Further, a bill-empty sensor  113  is installed in the frameboard  11  and adapted for providing a bill-empty signal when the bill chamber  12  is empty.  
         [0020]     The optical receiver module  2  is mounted in the housing  1  adjacent to the bill outlet  15 , for example, at a location beneath the bill passage  14 , and comprised of resistors, capacitors, phototransistors and an optical receiving device  21 . Further, the optical receiver module  2  is electrically connected to a control circuit (see  FIG. 4 ).  
         [0021]     The optical transmitter module  3  is mounted in the housing  1  adjacent to the bill outlet  15 , for example, at a location above the bill passage  14 , and comprised of resistors, capacitors, phototransistors and an optical transmitting device  31 . Further, the optical transmitter module  3  is electrically connected to the control circuit (see  FIG. 4 ). The control circuit controls the electric current going through the optical transmitting device  31 , thereby controlling the intensity of the light emitted by the optical transmitting device  31 . The light emitted by the light transmitting device  31  goes across the bill passage  14  toward the optical receiving device  21 , causing the optical receiving device  21  to output a signal to the control circuit for comparison with a reference value.  
         [0022]     The bill dispenser further comprises a transferring roller set  4  and a dispensing roller set  5 . The transferring roller set  4  is mounted in the accommodation chamber  13  below the frameboard  11 , comprising a number of transferring rollers  41  and an auxiliary roller  42 . Some transferring rollers  41  are provided with a respective push block  411 . The push blocks  411  are movable through the slots  111  into the bill chamber  12 . The dispensing roller set  5  is mounted in the bill chamber  12  between the frameboard  11  and the bill passage  14 . The dispensing roller set  5  is mounted in the bill chamber  12  above the frameboard  11 , comprising dispensing rollers  51 , adjustment rollers  52  and pressure rollers  53 . The dispensing rollers  51 , the adjustment rollers  52  and the pressure rollers  53  are for contacting the periphery of the transferring rollers  41 . The adjustment rollers  52  can be moved vertically to adjust a gap between the respective adjustment rollers  52  and the respective transferring rollers  41 .  
         [0023]     Further, the optical receiver module  2 , the optical transmitter module  3 , the transferring roller set  4 , the dispensing roller set  5  and the control circuit (see  FIG. 4 ) are electrically coupled to a drive (not shown), so that the control circuit controls the optical receiver module  2  and the optical transmitter module  3  to operate subject to the setting of a predetermined program, and drives the transferring roller set  4  and the dispensing roller set  5  to carry bills and to dispense bills. Further, the housing  1  can be connected to a host (not shown), enabling the host (computer, bill exchange machine or automatic vending machine) to control the operation of the control circuit (see  FIG. 4 ).  
         [0024]     Referring to  FIGS. 3, 5  and  6 , a stack of bills  6  of one denomination is placed in the bill chamber  12  inside the housing  1 . When dispensing a bill, the transferring roller set  4  is rotated clockwise. During rotation of the transferring rollers  41  and the auxiliary roller  42 , the push blocks  411  are moved with the respective transferring rollers  41  to rub against the first bill  6 , moving the bills  6  out of the bill chamber  12  to the dispensing rollers  51  of the dispensing roller set  5  toward the bill outlet  15 . When a number of bills  6  reached the dispensing rollers  51 , the dispensing rollers  51  stop the bills  6  into a stepped stack, and move the stepped stack of bills  6  to the pressure rollers  53 , for enabling the bills  6  to be dispensed through the gap between the adjustment rollers  52  and the corresponding transferring rollers  41  into the bill passage  14 . At this time, the optical receiver module  2  and the optical transmitter module  3  are driven to operate.  
         [0025]     When bills  6  are accommodated in the bill chamber  12 , the bill-empty sensor  113  is forced downwards by the accommodated bills  6 . When the bill chamber  12  is empty, the bill-empty sensor  113  receives no pressure, thereby outputting a signal indicative of the empty status of the bill chamber  12 .  
         [0026]     Referring to  FIG. 7 , during operation of the optical receiver module  2  and the optical transmitter module  3 , the control circuit (see  FIG. 4 ) runs subject to the steps as follows:  
         [0027]     ( 101 ) Start system initialization.  
         [0028]     ( 102 ) Judge whether or not a bill  6  is been dispensed? And then proceed to step ( 103 ) when positive, or step ( 102 ) when negative.  
         [0029]     ( 103 ) The optical transmitter module  3  transmits light toward the bill  6  passing through the bill passage  14 , and the optical receiver module  2  receives the transmissive light from the bill  2 . And then proceed to step ( 104 ).  
         [0030]     ( 104 ) Compare the value of the transmissive light received by the optical receiver module  2  with a predetermined reference value, and then proceed to step ( 105 ) if the difference of the comparison result is within a predetermined range, or proceed to step ( 106 ) if the difference of the comparison result surpasses the predetermined range.  
         [0031]     ( 105 ) The optical transmitter module  3  and the optical receiver module  2  keep detecting whether or not there is any bill  6  been dispensed? And then proceed to step ( 108 ) if positive, or step ( 106 ) if negative (beyond a predetermined length of time).  
         [0032]     ( 106 ) Reverse the dispensing roller set  5  to return the dispensing bill  6 , and then proceed to step ( 107 ).  
         [0033]     ( 107 ) Shut down the machine for troubleshooting.  
         [0034]     ( 108 ) End.  
         [0035]     As stated above, the invention uses an optical transmitter module  3  and an optical receiver module  2  to measure the transmittance of the light passing through the bill  6  that is being delivered through the bill passage  14  for comparison with a predetermined reference value. When two or more bills  6  are delivered through the bill passage  14 , the transmittance of the light passing through the bills  6  shows a significant difference relative to the predetermined reference value, and the control circuit will immediately reverse the dispensing roller set  5  to return the bills  6 .  
         [0036]     Further, the aforesaid reference value can be the transmittance of one single bill. Alternatively, the reference value can be the mean value of the transmittance of every single one of a predetermined number of bills been dispensed through the bill dispenser, then the reference value is programmed in the setting program of the control circuit.  
         [0037]     Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.