Abstract:
The card reader includes a main body  40  having a card passage  40 A, a magnetic head for reading the information recorded on a card  30 , an opening  42  provided in a card passage  41  of the main body  40 , and an elastic member  100  for biasing the magnetic head  70  from an outward position to an inward position of the card passage  41  through the opening  42 . Invasion preventing member  50 , provided in close contact with the circumference of the magnetic head  70 , is brought into contact with the main body  40 . As a result, invasion of foreign material into the card reader main body circuit unit  110  including the magnetic head  70  from the outside is prevented.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a card reader for reading data recorded on a card such as a magnetic card. 
     BACKGROUND OF THE INVENTION 
     A conventional card reader was designed for indoor use, and generally comprises a card passage provided in the main body, and an opening provided in the inner wall of the card passage. An elastic member for pushing from an outward position to an inward portion of the card passage, and a magnetic head unit integrated with this elastic member are placed in the opening. The magnetic head reads data recorded on a card. On the magnetic head-confronting side of the main body, there may be a circuit unit for processing the card data from the magnetic head. 
     FIG. 12 shows the shape of a conventional card reader main body. In the conventional card reader shown in FIG. 12, walls  46  (2 to 3 mm thick) are disposed at both sides of a card passage  41  for assuring stable running of the card. Both end portions  47  at which the card is inserted and passed through are shaped nearly at right angle to a mounting surface  48 . 
     FIG. 13 is a side view showing a mounting state of the main body of a conventional card reader on an operation panel (hereinafter called unit panel)  120  of an automatic vending machine installed at a filling station or the like. It shows the arrangement of the main body and the unit panel of the apparatus in which the conventional card reader is assembled. Waterproof sheets  130  are adhered to both end portions  47  and ceiling  465  of the card reader main body, and it shows the mode of inserting the main body into the unit panel  120 . 
     However, when such a conventional card reader is installed outdoors, it involves the following problems. Foreign material (water or other liquid, dust, etc.) may, invade inside through a gap between the main body opening and the magnetic head, or a gap at the junction between the main body upper surface and the unit panel in which the card reader is assembled. If foreign material deposits, adequate electric insulation in the terminals and circuits of the magnetic head may not be maintained. Therefore, the card data may not be read. 
     This problem may be solved by applying a waterproof coat of paint or sealant on the terminals of magnetic head, soldered parts of lead wires, and circuits. However, when assembling the card reader, this solution requires additional steps of applying the sealant, drying, and inspecting. In addition, if ice, dust or mud deposits on the spring for pressing the magnetic head, the spring guide, or the gap between the main body opening and the magnetic head, the motion of the magnetic head may be disturbed. Due to the disturbed motion, the card reader may not read the card data accurately. 
     As shown in FIG.  12  and FIG. 13, however, both end portions  47  of the conventional card reader are almost at right angles. The length of the unit panel  120  is defined to be D 120  and the dimension of the adhesion of the waterproof sheet to the card reader main body  40  is defined to be d 40 . In this case, in order to prevent invasion of foreign material, the dimension D 120  must not be much larger than the dimension d 40 . Accordingly, when mounting the card reader main body  40  on the unit panel  120 , the waterproof sheet  130  is likely to be peeled or torn. Therefore, in the shape of the card passage of the conventional card reader main body, it was extremely difficult to adhere the waterproof sheet on the upper side of the main body card passage, and assemble the card reader by adhering the card reader to the unit panel. 
     SUMMARY OF THE INVENTION 
     The invention is intended to solve the aforesaid problems. It is hence an object thereof to present a card reader capable of preventing invasion of foreign material from outside the card reader into parts of the card reader other than the card passage of the card reader, and preventing impediment of motion of the magnetic head by invasion of foreign material. To achieve the object, the card reader of the invention comprises a main body, a magnetic head for reading the data recorded on a card, and a gasket to prevent invasion of foreign material (water or other liquid, dust, etc.) The gasket is placed so as to be in close contact with the periphery of the magnetic head, and also in close contact with the main body. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an explanatory diagram showing a constitution of a card reader in an embodiment of the invention. 
     FIG. 2 is a diagram showing an assembled state of the card reader of the invention. 
     FIG. 3 is a diagram showing an operation panel using the card reader of the invention. 
     FIG. 4A is a front view showing the gasket used in the card reader of the invention. 
     FIG. 4B is a side view showing the gasket used in the card reader of the invention. 
     FIG. 4C is a side sectional view showing the gasket used in the card reader of the invention 
     FIG. 5A is a perspective exploded view of gasket, magnetic head and head holder of the invention. 
     FIG. 5B is a perspective view showing an assembled state of gasket, magnetic head and head holder of the invention. 
     FIG. 6 is a sectional view showing the mounting of the gasket on the main body of the card reader. 
     FIG. 7A is a sectional view showing the contacting portion of the invasion preventing member and the main body. 
     FIG. 7B is a sectional view of the contacting portion of the invasion preventing member and the main body. 
     FIG. 8A is a sectional view showing a first example of the contact between the main body and the invasion preventing member. 
     FIG. 8B is a sectional view showing a second example of the contact between the main body and the invasion preventing member. 
     FIG. 9A is a sectional view showing a third example of the contact between the main body and the invasion preventing member. 
     FIG. 9B is a sectional view showing a fourth example of the contact between the main body and the invasion preventing member. 
     FIG. 10 is a perspective view of a flange of the main body of the invention. 
     FIG. 11 is a sectional view showing a mode of adhering the card reader of the invention to an operation panel. 
     FIG. 12 is a perspective view of a flange of the main body of a conventional card reader. 
     FIG. 13 is a sectional view showing a mode of adhering the conventional card reader to an operation panel. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment of the invention is described below while referring to the accompanying drawings. FIG. 1 is a perspective exploded view showing a constitution of a card reader in a first embodiment of the invention. In FIG. 1, a card reader  20  includes a card reader main body  40 , a gasket  50  of elastic material such as rubber for preventing invasion of foreign material, and a head holder  60  for holding a magnetic head  70 . A spring retainer  80  presses the gasket  50  to the main body and has a fulcrum for providing energy by a spring force. A lead wire  90 , an elastic member (spring)  100 , mounting screws  120 , and a circuit unit  110  are also provided. 
     FIG. 2 is a perspective view of the card reader. It shows an assembled state of the card reader shown in FIG.  1 . The card reader shown in FIG. 2 is used as assembled in other devices. FIG. 3 shows an example of the card reader installed in an operation panel  10  of an vending machine at a filling station or the like. When a card  30  passes through a card passage  41 , the card reader  20  reads the data recorded on magnetic stripes  32 . 
     In this constitution, the main body  40  is composed of a synthetic resin such as ABS, and has a passage  41  formed in the center for allowing the card to pass. At both sides of the card passage  41 , guide walls  46  are provided for stabilizing running of the card, and the guide walls are orthogonal to a mounting surface of the card reader. A first guide wall  46  includes an opening  42  for inserting the magnetic head  70 , a boss  43  for holding the mounting screws of the spring retainer  80 , and a guide  430  of spring  100 . A second guide wall  46  includes a boss (not shown) for holding the mounting screws of the circuit unit  110 . 
     FIG. 4A, FIG.  4 B and FIG. 4C are explanatory drawings showing the gasket  50  used for preventing invasion of foreign material. FIG. 4A is a front view, FIG. 4B is a side view, and FIG. 4C is a side sectional view. Referring to FIG. 4A, FIG.  4 B and FIG. 4C, the gasket  50  is made of an elastic member such as rubber, and the magnetic head  70  is inserted therein. The gasket  50  includes an opening  52  for allowing the leading end having the core of the magnetic head  70  to be exposed to the outside of the gasket  50 , a magnetic head inserting portion (inner circumferential portion)  53 , and a folding portion  54  for allowing smooth motion of the magnetic head when inserting or passing the card in the shape of the junction from the magnetic head periphery to the outer circumference. The wall thickness of the folding portion  54  is thinner than the thickness of the magnetic head inserting portion  53  or the outer circumferential portion  56 . Further, as shown in FIG.  4 A and FIG. 5A, the dimension of the opening  52  of the gasket  50  and the overall dimension of the magnetic head  70  are set in the following relation: 
     D 1 &lt;d 1 , D 2 &lt;d 2 . 
     The head holder  60  is composed of synthetic resin such as ABS, and has a portion for press-fitting and fixing the magnetic head  70 , and a structure for nearly fixing the spring  100 . The spring retainer  80  is composed of synthetic resin such as ABS, and protects the head holder  60 , magnetic head  70 , gasket  50 , etc. The gasket  50  is placed between the spring retainer  80  and the peripheral edge portion  420  (see FIG. 1) of the opening  42  of the main body  40 . The spring retainer  80  is inserted into four screw fixing bosses  43  of the card reader main body  40 , and is fixed to the card reader main body  40  with screws  120 . A lead wire  90  is connected to a head terminal  72  in the upper part of the magnetic head  70  press-fitted into the head holder  60 . This lead wire  90  is connected to the circuit unit  110  provided on the confronting side of the magnetic head  70  of the card reader main body  40 . 
     FIG. 5A is a perspective exploded view of gasket  50 , magnetic head  70 , and head holder  60 . As shown in FIG. 5A, the spring  100 , head holder  60 , magnetic head  70 , and gasket  50  are assembled sequentially. FIG. 5B shows the assembled magnetic head unit  74 . 
     FIG. 6 shows the magnetic head unit  74  mounted on the card reader main body. In this unit  74 , the magnetic head  70  is inserted into the head holder  60 . The head holder  60  has a spring  100  for pressing the magnetic head  70  in a direction shown by the arrow A, and the magnetic head  70  is pressed by the spring  100  at the fulcrum of the spring retainer  80 . 
     Referring to FIG. 6, the motion of the head unit  74  is explained. When the card  30  is passed in the card passage  41  of the card reader  20  in the direction of arrow C, the magnetic head  70  installed in the center of gasket  50  reads the card data. The magnetic head  70  inserted in the head holder  60  is pressed in the direction of arrow A by the spring  100 . When the card is inserted, the magnetic head  70  moves in the direction of arrow B due to the thickness of the card. Until the card is taken out after being inserted, the magnetic head  70  and card  30  are always pressed by the spring  100  in the direction of arrow A and hence slide in close contact with each other. 
     In the gasket  50 , as shown in FIG. 4C, a folding portion  54  is provided between the periphery of the magnetic head inserting (inner circumferential) portion  53  and the outer circumferential portion  56 , and the folding portion  54  is thinly formed. Therefore, the gasket  50  moves and shrinks easily by following the motion of the magnetic head  70 . 
     When the card is not passing through the passage  41 , the magnetic head inserting portion (inner circumferential portion)  53  of the gasket  50  is pressed against the peripheral edge portion  420  of the main body by the energizing force of the spring  100 . Therefore, when the card does not pass through the passage  41 , invasion of foreign material can be prevented by close contact between the gasket  50  and the periphery of the magnetic head  70 , and close contact between the magnetic head inserting (inner circumferential) portion  53  of the gasket  50  and the peripheral edge portion  420  of the main body opening. 
     Further, by fastening the spring retainer  80  to the boss  43  of the main body  40  with screws, the outer circumferential portion  56  of the gasket  50  closely contacts the main body peripheral edge portion  420  of the opening. When the card passes through the passage  41 , invasion of foreign material can be prevented by close contact between the gasket  50  and the periphery of the magnetic head  70 , and close contact between the outer circumferential portion  56  of the gasket  50  and the main body peripheral edge portion  420  of the opening. 
     FIG.  7 A and FIG. 7B are sectional views showing the close contact between the main body and the invasion preventive member (i.e., gasket  50 ) having a slope. The opening edge  420  of the main body  40 , and the magnetic head inserting portion  53  of the gasket  50  are shaped so that the gasket  50  may contact the opening edge  420  of the main body  40  in a linear manner by spring force. A slope  58  is formed in gasket  50  as shown in FIG. 7A, or a rib protrusion  59  is formed around the magnetic head inserting portion of gasket  50  as shown in FIG.  7 B. 
     FIG.  8 A and FIG. 8B are sectional views showing the close contact between the slope of the main body and the invasion preventive member (i.e., gasket  50 ). In order that the gasket  50  may closely contact the main body opening edge  420  due to the spring force, a slope  44  is formed in the opening edge  420  as shown in FIG. 8A, or a rib protrusion  45  is formed in the opening edge  420  as shown in FIG.  8 B. 
     FIG.  9 A and FIG. 9B are sectional views showing close contact between the main body and the invasion preventing member. As shown in FIG. 9A, a slope  44  (slope angle a) is provided in the main body opening edge  420 , and a slope  58  (slope angle β) is provided around the magnetic head inserting portion  53  of the gasket. These angles are set so that the slope angle α and slope angle β may differ by more than several degrees from each other. As shown in FIG. 9A, the slope angle α of the main body opening peripheral edge portion  420  is set smaller than the slope angle β of the magnetic head inserting portion  53 . The dimension of the slope  44  of the main body opening peripheral edge portion  420  is set smaller than the dimension of the slope  58  of the magnetic head inserting portion  53 . In this case, the main body slope  44  contacts the gasket  50  in a linear manner. 
     Alternatively, as shown in FIG. 9B, the slope angle α of the main body opening peripheral edge portion  420  is set smaller than the slope angle β around the magnetic head inserting (inner circumferential) portion  53 . The dimension of the slope  44  of the main body opening peripheral edge portion  420  is set larger than the dimension of the slope  58  of the magnetic head inserting portion  53 . In this case, the slope  58  of the magnetic head inserting portion  53  contacts the main body slope  44  in a linear manner by the energizing force of the spring  100 . Both constitutions in FIG.  9 A and FIG. 9B are nearly the same in the effect of preventing invasion of foreign material. 
     FIG. 10 shows the shape of the card reader main body of the invention. In FIG. 10, flanges  49  are provided above the guide walls  46  at both sides of the card passage  41 , and are linked to both end portions  47 , and a slope is provided in at least one end portion  47 . 
     FIG. 11 is a side view of the main body of the card reader of the invention mounted on the unit panel  120  of the operation panel  10  of an automatic vending machine shown in FIG.  3 . Waterproof sheet members  130  are adhered to both end portions  47  and flanges  49  of the card reader main body, and the mode of inserting into the unit panel  120  is shown. 
     In FIG. 10, both end portions  47  of the card reader main body and the unit panel  120  are sloped. When mounting the card reader main body  40  on the unit panel  120 , the waterproof sheet  130  adhered to the card reader main body  40  can be placed in close contact with the unit panel  120 . Therefore, invasion of foreign material from this area can be prevented. 
     As clear from the description herein, the card reader of the invention can prevent invasion of water or dust into the magnetic head through the card passage of the main body by the invasion preventive member provided on the circumference of the magnetic head. 
     In the card reader of the invention, by lightly pressing the magnetic head into the invasion preventive member, the magnetic head is allowed to swing freely while preventing invasion of foreign material, so that the card can be read securely. 
     The card reader of the invention has a folding portion provided in the invasion preventive member so that the invasion preventive member can follow the motion of the magnetic head easily, and thereby the card can be read securely. 
     In the card reader of the invention, at least part of the invasion preventive member is formed thinly, and the elasticity is improved, so that the invasion preventive member can follow up the motion of the magnetic head easily, and thereby the card can be read securely. 
     In the card reader of the invention, when the card is not passing through the card passage of the main body, the invasion preventive member is always coming in contact with the main body with a specific pressure (because the spring is always pushing against the magnetic head), thereby consistently preventing invasion of foreign material. In the card reader of the invention, the slope of the magnetic head inserting portion of the invasion preventing member contacts the main body in a linear manner, and the surface pressure is increased as compared with the case of surface contact. Therefore, invasion of foreign material can be prevented securely. 
     In the card reader of the invention, the slope in the contacting portion of the opening edge linearly contacts the invasion preventing means at its rib leading end, and it is likely to be crushed. Therefore, invasion of foreign material can be prevented securely. 
     In the card reader of the invention, the slope of the opening edge linearly contacts the slope of the invasion preventing member, so that invasion of foreign material can be prevented securely. 
     In the card reader of the invention, moreover, since flanges are provided in the upper part of the card passage of the main body, it is easier to adhere the waterproof sheets closely to the unit panel at the flange side. 
     The adhering area of the waterproof sheet is wide, and the adhesion is increased, so that invasion of foreign material can be prevented securely. Moreover, since the flanges are wide, the creeping distance from the card passage to the circuit unit is increased, and the resistance to static electricity from the card is increased. 
     In the card reader of the invention, when adhering waterproof sheets to an area other than the card passage of the main body, it can be easily adhered to the unit side cover. Therefore, working problems such as peeling and tearing of the waterproof sheet can be avoided.