Abstract:
A card printer has a card conveyor for conveying along a card conveying route a card having a magnetic strip for storing data , a magnetic head bearer installed on a first side of the card conveying route, a magnetic head installed on the magnetic head bearer for accessing data of the magnetic strip, an encoder roller installed on a second side of the card conveying route for calculating a length of the card passing by the magnetic head, a cam for pushing the magnetic head away from the encoder roller after the magnetic head reads the data stored in the magnetic strip, and a thermal print head installed by one side of the card conveying route for printing a pattern onto the card after the cam pushes the magnetic head bearer to move away from the encoder roller.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a card printer, and more specifically, to a card printer having a cam to push a magnetic head bearer away from an encoder roller.  
         [0003]     2. Description of the Prior Art  
         [0004]     A card printer is an electronic device that can write data onto a magnetic strip of a card, read data from the magnetic strip, and print a predetermined pattern onto the card. Card printers have been widely applied to process items such as individual IDs (e.g. employee ID tags) and individual medical histories.  
         [0005]     The operation of the card printer is as follows. When a card enters a card printer, a magnetic head of the card printer writes data onto a magnetic strip of the card, and then reads data from the magnetic strip. After a processor in the card printer verifies the consistency of the data read by the magnetic head and the data previously written onto the magnetic strip, a thermal print head in the card printer prints the predetermined pattern onto the card.  
         [0006]     During the operation of the card printer according to the prior art, the magnetic head must be kept in contact with the magnetic strip in order to correctly write data onto or read data from the magnetic strip. Therefore, the card printer in the prior includes a fixed elastic piece set to ensure that the magnetic head keeps contacting with the card, i.e., the magnetic head keeps contacting with the magnetic strip in the card, when the card passes by the magnetic head. Unfortunately, the magnetic head has short life because of its constant contact with the card, and besides, interference due to the contact between the magnetic head and the card can have a destructive effect on clearance when the thermal print head is going to print the predetermined pattern onto the card.  
         [0007]     To solve the problem mentioned above, the thermal print head is located far from the magnetic head in the prior art card printer to make sure that when the thermal print head is printing the predetermined pattern onto the card, the card is kept away from the magnetic head and is unlikely to contact the magnetic head. However, this solution demands that the card reader be physically larger.  
       SUMMARY OF THE INVENTION  
       [0008]     The claimed invention provides a card printer having a cam to push a magnetic head bearer away from an encoder roller. The card printer comprises a card conveyor for conveying along a card conveying route a card having a magnetic strip for storing data; a magnetic head bearer installed on a first side of the card conveying route; a magnetic head installed on the magnetic head bearer for accessing data of the magnetic strip when the card passes by the magnetic head; an encoder roller installed on a second side of the card conveying route for calculating a length of the card passing by the magnetic head; a cam for pushing the magnetic head bearer away from the encoder roller after the magnetic head reads the data stored in the magnetic strip; and a thermal print head installed on one side of the card conveying route for printing a pattern onto the card after the cam pushes the magnetic head bearer away from the encoder roller.  
         [0009]     The claimed invention further provides a card printer having a cam to push a encoder roller bearer away from a magnetic head. The card printer comprises a card conveyor for conveying along a card conveying route a card having a magnetic strip for storing data; a magnetic head installed on a first side of the card conveying route for accessing data of the magnetic strip when the card passes by the magnetic head; an encoder roller bearer installed on a second side of the card conveying route; an encoder roller installed on the encoder roller bearer for calculating a length of the card passing by the magnetic head; a cam for pushing the encoder roller bearer away from the magnetic head after the magnetic head reads the data stored in the magnetic strip; and a thermal print head installed on one side of the card conveying route for printing a pattern onto the card after the cam pushes the encoder roller bearer away from the encoder roller.  
         [0010]     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  and  FIG. 2  are illustrations of a preferred exemplary embodiment of a card printer according to the present invention.  
         [0012]      FIG. 3  is an illustration of part of the card printer in  FIG. 1 .  
         [0013]      FIG. 4  is an illustration of a top view of the card printer in  FIG. 1 .  
         [0014]      FIG. 5  and  FIG. 6  are illustrations of a magnetic head, a magnetic head bearer, and a cam.  
         [0015]      FIG. 7  and  FIG. 8  are illustrations of the cam in  FIG. 5 .  
         [0016]      FIG. 9  and  FIG. 10  are exploded illustrations of the magnetic head, the magnetic head bearer, and the cam in  FIG. 5 .  
         [0017]      FIG. 11  and  FIG. 12  are illustrations of an encoder roller, an encoder roller bearer of the card printer in  FIG. 1 , and the cam in  FIG. 5 .  
         [0018]      FIG. 13  and  FIG. 14  are exploded illustrations of the encoder roller and the encoder roller bearer in  FIG. 11 .  
         [0019]      FIG. 15  and  FIG. 16  are illustrations of an idler, an idler bearer, a gear set, and an idle cam of the card printer in  FIG. 1 .  
         [0020]      FIG. 17  and  FIG. 18  are exploded illustrations of the idler, the idler bearer, the gear set, and the idle cam in  FIG. 15 .  
         [0021]      FIG. 19  is a functional block diagram of the card printer in  FIG. 1 . 
     
    
     DETAILED DESCRIPTION  
       [0022]     A card printer according to the present invention rotates a cam in accordance with the working status of a magnetic head. The card printer can further control the positions of a magnetic head bearer, an encoder roller bearer, and an idler bearer to be in a close-up position or in an open position. When the magnetic head of the card printer is writing data onto a magnetic strip of a card or reading data from the magnetic strip, the cam rotates to a cam close-up position to direct the magnetic head bearer, the encoder roller bearer, and the idler bearer to each close-up position in order to press the card against the magnetic head. Thus, the magnetic head can keep in contact with the magnetic strip, thereby writing data onto the magnetic strip or reading data from the strip. On the other hand, as a thermal print head of the card printer is printing a predetermined pattern onto the card, while the magnetic head is not operating, the cam rotates to a cam open position, which also directs the magnetic head bearer, the encoder roller bearer, and the idler bearer to each open position. In such situation, the magnetic head, the encoder roller on the encoder roller bearer, and the idler on the idler bearer do not contact the card. This allows the thermal print head to print the predetermined pattern onto the card without interference.  
         [0023]     Please refer to  FIG. 1  to  FIG. 4 .  FIG. 1  and  FIG. 2  are illustrations of a preferred exemplary embodiment of a card printer  10  according to the present invention.  FIG. 3  is an illustration of part of the card printer  10 .  FIG. 4  is an illustration of a top view of the card printer  10 . The card printer  10  comprises a card conveyor  71  for conveying along a card conveying route  14  a card  12  back and forth. The card  12  has a magnetic strip  16  for storing data. In the preferred exemplary embodiment of the present invention, the card conveyor  71  comprises a plurality of rollers  18 ,  20 , and  22 , an auxiliary roller  24 , and a plurality of gears  26  for corporately conveying the card  12  along the card conveying route  14 . The auxiliary roller  24  stabilizes the conveying when the card passes a magnetic head  28  of the card printer  10  (The magnetic head  28  is shown in  FIG. 5  and in  FIG. 6 .).  
         [0024]     The card printer  10  further comprises a plurality of bearing rollers  30  installed at both sides of the card conveying route  14  for confining the card  12  to be conveyed along the card conveying route  14 . With the plurality of bearing rollers  30 , the card  12  goes straight along the card conveying route  14  and is unlikely to deviate.  
         [0025]     Please refer to  FIG. 5  to  FIG. 10 .  FIG. 5  and  FIG. 6  are illustrations of the magnetic head  28 , a magnetic head bearer  36  for holding the magnetic head  28 , and a cam  38  of the card printer  10 .  FIG. 7  and  FIG. 8  are illustrations of the cam  38 .  FIG. 9  and  FIG. 10  are exploded illustrations of the magnetic head  28 , the magnetic head bearer  36 , and the cam  38 . The cam  38  comprises a magnetic head surface  40  and an encoder roller surface  42 . The magnetic head surface  40  comprises a long shaft  44  and a short shaft  46 . The encoder roller surface  42  comprises a long shaft  48  and a short shaft  50 . The magnetic head  28  in  FIG. 9  uses a plurality of springs  29  as supports to replace the elastic pieces in the prior art so that the magnetic head  28  can keep in contact with the magnetic strip  16 .  
         [0026]     Please refer to  FIG. 19 , which is a functional block diagram of the card printer  10 . The card printer  10  further comprises a sensor  73 , a motor  75 , and a thermal print head  77 . When the sensor  73  of the card printer  10  detects that the magnetic head  28  is writing data onto or reading data from the magnetic strip  16  of the card  12 , the sensor  73  drives the motor  75  to rotate the cam  38  to the cam close-up position, as  FIG. 8  shows. The cam  38  rotating to the cam close-up position presses against the magnetic head bearer  36  with the short shaft  46  of its magnetic head surface  40  so that the magnetic head bearer  36  is restrained in a magnetic head bearer close-up position, and the magnetic head  28  can keep contacting the magnetic strip  16  for writing data onto or reading data from the magnetic strip  16 , which is shown in  FIG. 5 . On the other hand, when the sensor  73  detects that the magnetic head  28  is neither writing data onto nor reading data from the magnetic strip  16  of the card  12 , it drives the motor  75  to rotate the cam  38  to a cam open position. As  FIG. 7  shows, the cam  38  rotating to the cam open position presses against the magnetic head bearer  36  with the long shaft  44  of its magnetic head surface  40  so that the magnetic head bearer  36  is restrained in the opening position, and the magnetic head  28  is not contacting the magnetic strip  16 , in other words, the magnetic head  28  is not contacting the card  12 , as  FIG. 6  shows.  
         [0027]     Please refer to  FIG. 7 ,  FIG. 8 , and  FIG. 11  to  FIG. 14 .  FIG. 11  and  FIG. 12  are illustrations of an encoder roller  52 , an encoder roller bearer  54  for holding the encoder roller  52 , and the cam  38 . The encoder roller  52  is for calculating a length of the card  12  passing by the magnetic head  28 .  FIG. 13  and  FIG. 14  are exploded illustrations of the encoder roller  52  and the encoder roller bearer  54 .  
         [0028]     Similarly, when the sensor  73  detects that the magnetic head  28  is operating, the sensor  73  drives the motor  75  to rotate the cam  38  to the cam close-up position. As  FIG. 8  shows, the cam  38  rotating to the cam close-up position presses against the encoder roller bearer  54  with the short shaft  50  of its encoder roller surface  42  so that the encoder roller bearer  54  is restrained in the encoder roller bearer close-up position and the encoder roller  52  can keep contacting the card  12 , as  FIG. 11  shows. On the other hand, when the sensor  73  detects that the magnetic head  28  is neither writing data onto nor reading data from the magnetic strip  16  of the card  12 , the sensor  73  drives the motor  75  to rotate the cam  38  to the cam open position. As  FIG. 7  shows, the cam  38  rotating to the opening position presses against the encoder roller bearer  54  with the long shaft  48  of its encoder roller surface  42  so that the encoder roller bearer  54  is restrained in the opening position and the encoder roller  52  is not contacting the card  12 , as  FIG. 12  shows.  
         [0029]     Please refer to  FIG. 15  to  FIG. 18 .  FIG. 15  and  FIG. 16  are illustrations of idlers  56 , an idler bearer  58  for holding the idlers  56 , a gear set  60 , and an idle cam  62 . The idlers  56  are for pressing against the card  12  when the card  12  conveyed to the card conveying route  14 . One end of the gear set  60  is connected to the cam  38  and another end is connected to an idle cam  62 . The idle cam  62  comprises a long shaft  62  and a short shaft  66 .  FIG. 17  and  FIG. 18  are exploded illustrations of the idlers  56 , the idler bearer  58 , the gear set  60 , and the idle cam  62 .  
         [0030]     Similarly, when the sensor  73  detects that the magnetic head  28  is operating, the sensor  73  drives the motor  75  to rotate the cam  38  to the cam close-up position. As  FIG. 8  shows, since the idle cam  62  is connected to the cam  38  through the gear set  60 , the idle cam  62  rotates to an idle cam close-up position and presses against the idler bearer  58  with its short shaft  66  so that the idler bearer  58  is restrained in an idler bearer close-up position and the idler  58  can press against the card  12 , as  FIG. 15  shows. On the other hand, when the sensor  73  detects that the magnetic head  28  is neither writing data onto nor reading data from the magnetic strip  16  of the card  12 , the sensor  73  drives the motor  75  to rotate the cam  38  to the cam open position. As  FIG. 7  shows, the motor  75  also rotates the idle cam  62  to an idle cam opening position. The idle cam  62  rotating to the idle cam open position presses against the idler bearer  58  with its long shaft  64  so that the idler bearer  58  is restrained in its opening position and the idler  56  is not contacting the card  12 , as  FIG. 18  shows.  
         [0031]     A thermal print head of the card printer  10  is installed on one side of the card conveying route  14  for printing a pattern onto the card  12  when the magnetic head  28  stop operating. As mentioned above, when the magnetic head  28  stops operating, i.e., when the sensor  73  detects that the magnetic head  28  is neither writing data onto nor reading data from the magnetic strip  16  of the card  12 , the sensor  73  drives the motor  75  to rotate the cam  38  to the cam open position, where the cam  38  can restrain the magnetic head bearer  36  and the encoder roller bearer  54  to their individual open positions respectively. In the meantime, the sensor  73  further drives the motor  75  to rotate the idle cam  62  connected with the cam  38  to the idle cam opening position. In such situation, the magnetic head  28 , the encoder roller  52 , and the idler  56  are separate from the card  12  so that the thermal print head  77  can print the pattern onto the card  12  without interference.  
         [0032]     Please refer to  FIG. 3 . The card printer  10  further comprises an enabling sensor  32  and an encoder roller sensor  34 , both installed along the card conveying route  14 . The enabling sensor  32  is for generating an enabling signal to enable the magnetic head  28  when the card  12  passes by the enabling sensor  32 . The encoder roller sensor  34  is located opposite the magnetic head  28  for calculating the length of the card  12  passing by the magnetic head  28 .  
         [0033]     The card printer  10  further comprises an automatic card feeder  79 , which is shown in  FIG. 4 , for containing the card  12  and feeding the card  12  into the card conveying route  14 .  
         [0034]     The card printer  10  according to the present invention has the feature that the magnetic head  28 , the encoder roller  52 , and the idler  56  contact the card  12  when the magnetic head is operating, and are removed from the card  12  when the magnetic head  12  is not operating, i.e., the thermal print head  77  is printing the pattern onto the card  12 . With the feature of the card printer  10 , the thermal print head  77  can print the pattern onto the card  12  without interference.  
         [0035]     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.