IC card and connector therefor

A shuttered card-edge type IC card including a base having springs therein and a circuit board, a shutter and a cover provided in succession on at least one surface of the base. The base is formed with guide grooves and guide and spring receiving grooves. The springs are located in the guide and spring receiving grooves to close the shutter. The shutter is provided with pawls to be fitted in the guide grooves, respectively, for guiding the pawls in the guide grooves. The shutter is further provided with spring bias plates to be fitted in the guide and spring receiving grooves, respectively, for guiding the spring bias plates in the guide and spring receiving grooves and biasing the spring bias plates by the springs located therein. The connector comprises ridges located corresponding to the guide grooves of the base of the IC card and to be fitted in the guide grooves. The shutter of this IC card is not easily opened even if any member contacts the card in carrying or using it. Terminals of the IC card are securely in contact with contacts of the connector when the card is inserted into the connector of an electric computer.

BACKGROUND OF THE INVENTION 
This invention relates to an IC card for use in electronic computers and 
other devices of this kind, particularly a shuttered card-edge type IC 
card and a connector for connecting the card. 
An IC card has been used for supplying informations to be inputted into or 
writing informations to be outputted from electronic computers, 
particularly console units thereof or small electronic computers into 
which the IC card is inserted. In handling the IC card, there is a risk of 
memorized informations being broken down if a user's hand touches a 
connecting terminal portion of the card. 
In order to avoid such an accident, an IC card as shown in FIG. 1 has been 
widely used. This IC card has a memory portion coated with a coating 112 
of a synthetic resin or the like except a connecting terminal portion 111. 
Moreover, the IC card is provided with a movable shutter 113 between the 
connecting terminal portion 111 and the coating 112 for covering the 
terminal portion 111. 
With this arrangement, when this IC card is inserted a connector provided 
in an electronic computer or the like, operating pawls 114 provided on 
both sides of the shutter 113 are pushed rearward so as to expose the 
connecting terminal portion to establish a connection between the card and 
the connector. When this card is drawn from the connector, the shutter 13 
is automatically returned by an action of a spring 115 provided between 
the shutter 113 and the coating 112 to cover the connecting terminal 
portion 111. The IC card shown in FIG. 1 is a typical one of this kind, 
which has generally 80-90 mm length, 50-60 mm width and 1.5-2.5 mm 
thickness. 
The shuttered IC card of the prior art as above described is superior in 
prevention of dust because of the shutter covering the terminal portion 
except when being used. Moreover, the shutter somewhat serves as an 
electrostatic shield. However, such a shuttered IC card encountered the 
following problems to be solved. 
(1) As the operating pawls 114 extend outwardly, there is a risk of the 
pawls unintentionally brought into contact with another member when it is 
being used or carried to open the shutter 113, resulting in an unexpected 
accident. 
(2) The terminal portion 3 is arranged on only one side of the IC card, so 
that it cannot provide for the increased number of terminals due to the 
improvement of integrated degree. Accordingly, this IC card does not 
fulfil the requirement of providing with terminals as many as possible. 
Such a requirement has become acuter with the increase in memory capacity 
of IC cards. 
(3) The shutter 21 is electrically independent from a circuit in the IC 
card, so that the shutter 21 is not necessarily at the same potential as 
the ground of the circuit in the IC card. Therefore, if the shutter is 
charged with static electricity for any reason, it may discharge to the 
circuit in the card, so that the circuit is often damaged. 
(4) The IC card and the connector are electrically independent from each 
other before being connected, so that grounds of the connector and IC card 
are not necessarily at the same potential. In the event that they are at 
different potential, when the IC card is inserted into the connector, 
electromagnetic troubles often occur in either or both the IC card and 
electronic equipment on the side of the connector. 
SUMMARY OF THE INVENTION 
It is a primary object of the invention to provide an IC card and a 
connector for connecting the IC card whose shutter is not easily opened 
even if any member contacts the card in carrying or using it and whose 
terminals are securely in contact with contacts of the connector when the 
card is inserted into the connector of an electronic computer. 
It is another object of the invention to provide an IC card whose number of 
terminals has been increased to the maximum possible number, maintaining 
the advantages of the IC cards of the prior art. 
It is a further object of the invention to provide a shuttered IC card 
having a shutter adapted to provide for electrostatic trouble. 
It is an object of the invention to provide a connector which does not 
cause any electromagnetic trouble even if a ground of an IC card is at a 
potential different from that of a ground on a side of the connector. 
In order to achieve these objects, in a shuttered card-edge type IC card 
including a base having springs therein and a circuit board, a shutter and 
a cover provided in succession on at least one surface of the base, 
according to the invention the base is formed with guide grooves and guide 
and spring receiving grooves and the springs for closing the shutter are 
located in the guide and spring receiving grooves, and the shutter is 
provided with pawls to be fitted in the guide grooves, respectively, for 
guiding the pawls in the guide grooves and the shutter is further provided 
with spring bias plates to be fitted in the guide and spring receiving 
grooves, respectively, for guiding the spring bias plates in the guide and 
spring receiving grooves and biasing the spring bias plates by the springs 
located therein. 
According to the invention, the shutter is closed by compressive reaction 
force of the springs received in the base of the card, and opened by 
ridges provided in a connector into which the card is inserted. 
In a preferred embodiment of the invention, the guide grooves for guiding 
the pawls for opening the shutter is provided on the opposite side of 
terminals with respect to the base so that a surface on the side of the 
terminals is used only for providing terminals. 
In another embodiment, the terminals and shutters are provided on both 
surfaces of the base and the two shutters are connected so as to be 
operated simultaneously. 
According to the invention, the shutter and the ground of the internal 
circuit are electrically conductive through the springs for closing the 
shutter. 
The connector according to the invention comprises an insulating block 
provided therein with ridges made of a conductive material corresponding 
in position and dimension to I-shaped grooves formed in the base of the IC 
card, and the ridges and the ground of an electronic equipment on a side 
of the connector are electrically connected. 
The invention will be more fully understood by referring to the following 
detailed specification and claims taken in connection with the appended 
drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The IC card according to the invention comprises in outline a base A having 
springs E provided therein, and a circuit board B, a shutter C and a cover 
D arranged in succession on at least one surface of the base A. 
FIG. 2 illustrates one embodiment of the IC card according to the invention 
showing principal parts constituting the card and the relations 
therebetween. 
In FIG. 2, the IC card comprises a base, a circuit board provided thereon 
with for example an integrated circuit, and a shutter C covering a 
terminal portion 3 of the circuit board B and provided between the circuit 
board and an upper surface cover D. The upper surface cover D covers the 
circuit board B except its terminal portion 3 and the shutter plate C. The 
IC card further comprises springs E located in spring receiving grooves 33 
formed in a bottom surface of the base A and a bottom cover F for the base 
A. The principal parts of the IC card shown in FIG. 2 will be explained in 
detail hereinafter. 
The base A is formed in its upper surface with shutter guide grooves 31 
(referred to hereinafter "I-shaped grooves") for guiding pawls 21 of the 
shutter C and with guide grooves 32 (referred to hereinafter "T-shaped 
grooves") for guiding pawls 22 having spring bias plates 23 of the shutter 
C. The T-shaped grooves 32 communicate with the spring receiving grooves 
33 formed in the bottom surface of the base A as later explained referring 
to FIGS. 4-7. 
The I-shaped grooves 31, extend halfway in their depth directions over a 
thickness of the base A without extending through the base A. Although 
there is no limited condition for the I-shaped grooves 31 other then their 
depth, they are so designed as to be able to guide the pawls 21 in 
response to a movement of the shutter C. In general, a depth of 0.5 mm of 
the grooves suffices to ensure their performance. By determining the depth 
of the I-shaped grooves in this manner, it is possible to distinguish one 
surface of the card from the other surface clearly to prevent an erroneous 
insertion of the card into the connector. 
Moreover, the base A of the IC card according to the invention is usually 
provided a frame 35 for settling the circuit board B or the like thereon 
as shown in FIG. 2. The circuit board B to be arranged on the base A often 
includes an IC chip 1, a battery (not shown), switches (not shown) and 
others having thicknesses. In this case, the base A is formed with a 
recess 34 corresponding to these parts for receiving them. 
FIG. 4 is a perspective view illustrating the base A turned upside down. As 
shown in FIG. 4, the base A is formed in its bottom surface with the 
spring receiving grooves 33 capable of receiving the springs E having 
their free lengths. 
FIG. 5 is a bottom plan view of the base A and FIGS. 6a, 6b and 6c are 
sectional view taken along lines VIa--VIa, VIb--VIb and VIc--VIc in FIG. 
5. As can be seen from these drawings, the T-shaped grooves 32 on the 
upper surface of the base A are shorter than the spring receiving grooves 
33 provided in the bottom surface of the base A. 
FIG. 7 illustrates the spring E received in the spring receiving groove 33. 
As the spring receiving grooves 33 have lengths equal to or longer than 
the free lengths of the spring E, these springs E are easily located in 
the spring receiving grooves 33. After the springs E are arranged in the 
grooves 33, the grooves 33 are covered by the bottom cover F. The bottom 
cover F is not necessarily a cover covering all over the bottom surface of 
the base A so long as the cover F is capable of preventing the springs E 
from jumping out of the spring receiving grooves 33. A material, a 
thickness and the like of the bottom cover F are preferably selected in 
the same manner as in the shutter C without particular requirements. In 
general, the bottom cover F is preferably made of a stainless steel plate. 
Moreover, the base A is preferably or the like without any limitation. In 
consideration of its configuration, weight, workability, durability, cost 
and the like, materials for the base A are resins and as polyethylene, 
polypropylene, polyvinyl chloride, polystyrene, polyamide, polycarbonate, 
polyester, polyphenylene oxide, polyphenylene sulfide, fluorine plastic 
material and the like or copolymers of these plastic materials, mixed 
resins and the like. Among these materials, polyethylene, polypropylene, 
polyvinyl chloride, polyamide, polyester and the like and copolymers 
thereof are widely used for the base A. 
Any circuit boards of generally known IC cards can be used as the circuit 
board B for the IC card according to the invention. Although the circuit 
board B has been shown in FIG. 2 devoid of the portion corresponding to 
the I-shaped grooves 31 and T-shaped grooves 32, any configuration of the 
circuit board B other than that shown may be employed so long as it does 
not interfere with the movement of the pawls 21 and 22 of the shutter C. 
This is only a problem in designing the circuit board. FIG. 2 exemplarily 
illustrates the IC provided on the circuit board B, terminals 2 of the IC, 
terminals 3 of the circuit board B, and a wiring 4 of the circuit. 
Moreover, a circuit of an IC card may be formed directly on the base A. In 
this case, the independent circuit board can be dispensed with. 
FIG. 3 is a perspective view illustrating the shutter C shown in FIG. 2 
turned upside down. The shutter C is provided with pawls 21 and 22 for 
guiding the movement of the shutter C. The pawls 21 and 22 arranged one on 
forward and rearward sides suffice to perform their functions. If more 
smooth movement of the shutter is required, two or more pawls 21 and 22 
are preferably provided one on the forward and rearward sides. By 
arranging, for example, two pawls 21 and two pawls 22 spaced apart by 
sufficient distances, the shutter C is moved only when these pawls are 
subjected to substantially uniform forces but not moved upon being 
subjected to unequal forces. This effect is preferable in inserting the 
card into a connector. 
According to the invention, the pawls 22 on the front side in an opening 
direction of the shutter are provided at their ends with the spring bias 
plates 23. The spring bias plate 23 compress the spring E when the shutter 
is opened, and is subjected to a compressive reaction force of the spring 
when the shutter is closed. This compressive reaction force serves to 
close the shutter. The shutter moves on the circuit board B. For the 
purpose of protecting the circuit board B and making smooth the movement 
of the shutter, the shutter may be provided on a side of the circuit board 
with a coating film. In consideration of wear-resistant, lubricating and 
insulating properties, a material for the coating film is used such as 
polytetrafluoroethylene, polyamide, polyester, crosslinked polyethylene, 
polyphenylene oxide, polysulfone, polyphenylene sulfide, and the like. 
A material of the shutter C is not particularly limited. In consideration 
of thinness, robustness, durability and the like required as a shutter, a 
metal, particularly a stainless steel is preferable. 
FIGS. 8 and 9 are drawings for explaining how to mount the shutter C after 
the circuit board B has been provided on the base A. FIG. 8 particularly 
shows the spring E with its free length received in the spring receiving 
grooves 33 formed in the bottom surface of the base A as viewed from the 
T-shaped groove 32 in the upper surface of the base A. In this case, a jig 
81 in the form of a bar is inserted through the T-shaped groove into the 
spring E. Thereafter, the jig 81 is moved as shown in FIG. 9, so that the 
spring E is compressed until an end 61 of the spring E arrives at a narrow 
portion 32b of the groove 32 after it has passed a wide portion 32a of the 
groove 32. Then the pawls 22 having spring bias plates 23 and the pawls 21 
of the shutter C are into the wide portion 32a of the T-shaped grooves 32 
and the I-shaped grooves 31, respectively to secure the shutter on the 
base A. 
Moreover, the upper cover D is secured to the shutter C. A material of the 
upper cover D is selected in the same manner in the shutter C and the 
bottom cover F. 
The springs E for closing the shutter C of the IC card according to the 
invention may be any elongated compression springs. However, coil springs 
formed by winding spring steel wires about axes and leaf springs formed by 
zigzag bending band-like spring steel. From the view-points of durability, 
facility in handling, cost and the like, the coil springs are more 
preferable. 
The shutter C of the IC card according to the invention is moved by the 
action of the springs, which will be explained in detail. FIGS. 10a and 
10b are drawings for explaining the relation between compressive 
deformations and functions of the spring E used in the invention. 
Referring to FIG. 10a, the free length is a length of the spring not 
subjected to any compressive force, and I indicates a pre-compressive 
deformation which the spring exhibits when the shutter is completely 
closed and II indicates a deformation of the spring between the completely 
closed position and the fully opened position of the shutter. When the 
shutter is completely closed, it is subjected to the compressive force 
corresponding to the pre-compressive deformation. When the shutter is 
fully opened, it is subjected to the compressive force corresponding to 
the pre-compressive deformation I plus the deformation II. FIG. 10b 
illustrates a relation between the compressive reaction force and the 
deformation of the spring shown in FIG. 10a. In FIG. 10a, for example, the 
pre-compressive force in the spring at the pre-compressive deformation 
corresponds to a force acting upon the completely closed shutter. It is 
understood that the shutter would not open unless any more force 
effectively acts upon the shutter. 
With the card explained referring to FIGS. 2-10b, the grooves 31 for 
guiding the jaws of the shutter C are provided in the same surface as that 
on which the terminals are arranged, so that the area in which the 
terminals are arranged becomes narrower by the area occupied by the 
grooves 31. As shown in FIGS. 11a and 11b, however, if grooves 31 are 
formed in a surface of the base A opposite to a surface on which a circuit 
board B is located, the memory capacity of the IC card increases to 
provide for the requirement to have terminals as many as possible. 
FIG. 11a perspectively illustrates another IC card according to the 
invention. FIG. 11b is an exploded perspective view of the IC card shown 
in FIG. 11a. 
As shown in FIGS. 11a and 11b, the base A is formed in a bottom surface 
with the grooves 31 for guiding the pawls 21 of the shutter C. Moreover, 
the shutter C is provided with the pawls 21 corresponding to the pawls 21 
of the base A. 
FIG. 12a illustrates how to secure the shutter C to the board B and base A. 
FIG. 12b shows a configuration of the shutter secured to the board B and 
base A. As shown in FIGS. 12a, pawls 21, connecting portions 24 and spring 
bias plates 23 are formed in L-shaped members. These L-shaped members are 
passed through the spring receiving grooves 32 from upper surface to 
bottom surface of the base A so that the shutter C is arranged on the 
circuit board B provided on the base A. Thereafter, the connecting 
portions 24 and the pawls 21 are bent toward the shutter C into the form 
of a hair pin shown in two-dot-and-dash lines in FIG. 12a. In this manner, 
the shutter C is formed into the shape shown in FIG. 2b and the pawls 21 
and the connecting portions are received in the grooves 31 in the bottom 
surface of the base A. 
The shutter C of the IC card according to the invention is only required to 
have the configuration as shown in FIG. 12b. It may be made by any method 
other than that above described. For example, it may be that shown in 
FIGS. 13a and 13b. As shown in FIG. 13a, a shutter C provided with spring 
bias plates 23 is jointed by welding to separately made members consisting 
of pawls 21, connecting portions 24 and jointing portions 23'. In this 
case, the spring bias plates 23 and the jointing portions 23' are 
connected by welding. 
FIG. 14 illustrates another modification of the shutter C, wherein a 
shutter C provided with spring bias plates 23 is connected by welding to a 
separately made member consisting of a connecting portion 24 provided with 
pawls 21 and jointing portions 23'. In this case, the spring bias plates 
23 and the jointing portions 23' are connected by welding. 
The IC cards according to the invention shown in FIG. 2 and FIGS. 11a and 
11b are provided with the terminals only on one surfaces of the cards, so 
that they do not sufficiently provide for the requirement to increase the 
terminals as many as possible. In order to fulfil such a requirement, 
terminals are provided on both surfaces of the card. 
FIG. 15 is a perspective view illustrating an IC card having terminals on 
both the surfaces of the card. The IC card comprises on a bottom side a 
circuit board B', a shutter C' (not shown) and a cover D' successively 
provided corresponding to those on an upper side. 
FIGS. 16a-16d illustrate various modifications of the shutter used in the 
IC card according to the invention. For the reason that the shutters C and 
C' provided on the upper and lower surfaces of the base A are 
simultaneously closed and opened, and for the other reasons, these 
shutters C and C' are connected with each other. Any connecting methods 
may be employed for this purpose, which are shown in FIGS. 16a-16d. 
In FIG. 16a, two shutters C and C' are connected to form a rectangular 
cylinder having pawls 21 and 21' integrally connected. In this case, the 
base A is provided on both sides with grooves 36 for enabling the 
connecting portions 24 of the shutters C and C' to move therealong. 
FIG. 16b illustrates two shutters C and C' connected into a U-shaped member 
to overlap pawls 21 of the respective shutters C and C'. In this case, one 
edge of the base A is cut off to form grooves 36 for permitting connecting 
portion 24 of the shutters C and C' to move therealong. Covers D and D' 
covering the outermost surfaces of the IC card are connected into an 
integral U-shaped cover. 
FIG. 16c illustrates two separately made upper and lower shutters C and C' 
connected by pawls 21 and 21' to form a unitary body. 
FIG. 16d shows two shutters C and C' connected into a U-shaped member. 
However, either of the overlapped pawls 21 of the shutters C and C' is 
dispensed with. In this case, grooves 31 may be provided one in each 
surface of the base A. 
According to the invention, the guide grooves 31 provided in the base A for 
the shutters C and C' are more than two, and shapes and sectional shapes 
of the guide grooves 31 are made different from each other or they are 
provided in asymmetry, thereby enabling both surfaces of the IC card to be 
distinguishable. 
In the IC card according to the invention, electrostatic trouble can be 
prevented by electrically connecting the ground of the circuit board B and 
the shutter C in the card. 
Any system may be employed, so long as the ground of the internal circuit 
and the shutter become conductive. Embodiments for this purpose will be 
explained by referring to FIGS. 17a-17d. 
In FIG. 17a, a spring E to be located in a T-shaped groove 32 has one end 
abutting against a spring bias pawl 23 of a shutter C and the other end 11 
which is substantially straight extended and formed with a curved portion. 
The curved portion of the end 11 of the spring is inserted between the 
base A and the circuit board B so as to be connected with the ground of 
the circuit board B. As the one end of the spring E located in the 
T-shaped groove 32 is in contact with the spring bias pawl 23, the ground 
of the circuit board B and the shutter C become conductive through the 
spring E. 
In FIG. 17b-1, between a T-shaped groove 32 formed in a base A and a spring 
E is interposed a contact member 12 having one end abutting against one 
end of the spring E and the other end 13 adapted to be connected to a 
ground of the circuit board B. 
One example of the contact member 12 being secured to the base A is shown 
in FIG. 17b-2, wherein the contact member is pivotally connected to the 
base A with the aid of projections integrally formed in the contact member 
12 to obtain a stable connection. 
In FIG. 17C, a contact 14 connected to the ground of the circuit board B is 
planted in the circuit board B and interposed between the T-shaped groove 
32 of the base A and the spring E. In this manner, the shutter C and the 
ground of the circuit board B become conductive through the spring E. 
In FIG. 17d, the circuit board B is provided in the proximity of the 
T-shaped groove 32 with a suitably sized ground terminal contact 15 which 
is bent into the T-shaped groove 32 so as to bring the contact 15 into 
contact with the spring E to obtain an electrical connection between the 
shutter C and the ground of the circuit board B. 
Most preferable connectors for the IC cards according to the invention are 
shown in FIGS. 18a-20c. Particularly, the connector shown in FIGS. 18a-18c 
is used for the IC card shown in FIG. 2, the connector shown in FIGS. 
19a-19c for the IC card having the terminals on both the surfaces shown in 
FIG. 15 and the connector shown in FIGS. 20a-20c for the IC card shown in 
FIGS. 17a-17d providing for the electrostatic trouble. 
In FIGS. 18a-20c, each an insulating block 101 has contacts 102 planted 
therein and is formed with guide legs 103 formed with guide grooves 104. 
The guide legs 103 are not essential for constituting the invention but 
serve to bring about more effective results. The insulating block 101 is 
formed inside with ridges 105 having positions and dimensions capable of 
fitting in the I-shaped grooves 31 provided in the base A of the IC card 
according to the invention to be inserted into the insulating block 101 
with the aid of the guidance of the guide legs 103. 
The ridges 105' provided in the insulating block 101 shown in FIGS. 20a-20c 
are made of a conductive material. Its one example is shown in FIG. 21. 
The ridge 105' shown in FIG. 21 is obtained by stamping or punching a 
metal plate of copper, copper alloy or the like as used for contacts of 
connectors into a predetermined shape and further applying to the punched 
metal plate a suitable working such as pressing. The conductive ridges 
105' may be formed from a conductive synthetic resin. Reference numeral 
106 denotes a terminal to be connected to a ground of an electronic 
equipment on the side of the connector. 
When the IC card according to the invention is being inserted into the 
connector along the guide grooves 104 in the guide legs 103, the pawls 21 
of the shutter C of the IC card are raised by the ridges 105 provided in 
the insulating block 101 of the connector so as to expose the terminals 3 
of the circuit board B of the IC card, thereby bringing the terminals 3 
into contact with the contacts 102 of the insulating block 101 of the 
connector. On the other hand, when the IC card inserted in the insulating 
block 101 of the connector is drawn out of the insulating block 101, the 
shutter C of the IC card covers the terminals of the IC card in its 
completely closed position with the aid of the compressive reaction force 
of the springs arranged in the base A of the IC card. As can be seen from 
this explanation, the ridges 105 formed in the insulating block 101 and 
the I-shaped grooves 31 provided in the base A of the IC card are in a 
relation as if the ridges 105 and the I-shaped grooves were a "key" and a 
"lock", so that a wrong insertion of the IC card turned upside down is 
prevented even in a dark location. 
The operation of the IC card in the case of the ridges 105 in the 
insulating block being the conductive ridges 105' will be explained. When 
the shuttered IC card is being inserted into the connector along the guide 
grooves 104 of the guide legs 103, the shutter pawls 21 of the IC card are 
brought into contact with the conductive ridges 105' in the insulating 
block 101 of the connector so that the shutter C and the ridges 105' of 
the connector become conductive before the shutter is opened. Upon further 
insertion of the IC card into the connector, the pawls 21 of the shutter C 
of the IC card are raised by the conductive ridges 105' to expose the 
terminals 3 of the circuit board B of the IC card so as to bring the 
terminals 3 into contact with the contacts 102 planted in the insulating 
block 101 of the connector. Furthermore, when the IC card is drawn out of 
the insulating block 101 of the connector, the shutter C of the IC card 
covers in its fully opened condition the exposed portion of the IC card 
with the aid of the compressive reaction force of the springs located in 
the base A of the IC card. 
Namely, when the shuttered IC card for providing for the electrostatic 
trouble as shown in FIGS. 17a-17d is inserted into the connector shown in 
FIGS. 20a-20c, the shutter C of the IC card and the conductive ridges 105' 
of the connector become conductive before the terminals 3 of the IC card 
is brought into contact with the contacts 103 of the connector. When the 
IC card is drawn out of the connector, the terminals of the IC card are 
out of contact with the contacts of the connector and are covered by the 
shutter and thereafter the shutter C leaves away from the conductive 
ridges of the connector. 
The IC card and the connector therefor constructed as above described have 
the following various significant effects which are brought about only by 
the invention. 
(1) The IC card according to the invention is devoid of projections 
outwardly provided for closing and opening a shutter, so that inadvertent 
opening of the shutter is prevented. There is no risk of erroneous 
operation of the card caused by the inadvertent opening of the shutter. 
The reliability of the card is high. 
(2) The closed shutter is kept by the precompressive force of the springs. 
It does not open by a weak force and tight closing of the shutter is 
ensured. For example, therefore, even if the IC card is carried with a 
user in his pocket for a long period of time, contamination of the card 
suffering from dust is prevented as possible. 
(3) The springs used in the card are compression coil springs which exhibit 
less fatigue in repeated use to improve the reliability of the card. 
(4) The two I-shaped grooves spaced from each other are arranged one on 
each side of the base of the card. The IC card is prevented from inserting 
into the connector unless the IC card is pressed by substantially equal 
forces acting upon both the sides simultaneously. Therefore, the 
reliability on correct insertion of the card into the connector is 
improved and correct connecting between the card and the connector is 
ensured. 
(5) The I-shaped grooves in the base of the card have the depths which do 
not pass through the base. Therefore, the upper and lower surfaces of the 
IC card are clearly distinguishable from each other. Moreover, the 
connector is provided with opposed ridges to prevent the wrong insertion 
of the card turned upside down into the connector and to ensure the 
correct insertion of the card with the aid of the guidance of the ridges. 
(6) The guide grooves are provided in the back surface of the base A of the 
card to enable the terminals 3 to be arranged on overall width of the IC 
card, so that the memory capacity of the card is increased to fulfil the 
requirement in the field of the industry to provide terminals as many as 
possible. 
(7) Terminal portions are provided on both the surfaces of the IC card to 
increase twice the number of the terminal. 
(8) The two shutters provided on both the surfaces of the base A of the 
card are connected to each other. These two shutters are securely 
simultaneously closed and opened when required, the reliability of the 
shutter in closing and opening is improved. 
(9) A plurality of the guide grooves 31 and the T-shaped guide grooves 32 
for guiding the shutter are provided to ensure smooth closing and opening 
of the shutter. 
(10) By modifying the sectional shapes of the guide grooves 31 for by 
arranging the guide grooves 31 in asymmetry, the upper and lower surfaces 
of the IC card are distinguishable from each other. Moreover, the 
connector is provided with ridges corresponding to the guide grooves 31 to 
prevent the IC card from being erroneously inserted into the connector. 
(11) The shutter and the ground of the internal circuit of the IC card are 
kept at substantially the same potential so that any electrostatic trouble 
between the shutter and the internal circuit is eliminated. 
(12) It is possible to maintain the shutter of the IC card and electronic 
equipment on the side of the connector at substantially the same 
potential. Therefore, so long as the internal circuit and the shutter in 
the IC card are electrically connected, the internal circuit of the IC 
card and the electronic equipment on the side of the connector are 
electrically connected to eliminate any electromagnetic trouble such as 
the electrostatic trouble therebetween. 
While the invention has been particularly shown and described with 
reference to preferred embodiments thereof, it will be understood by those 
skilled in the art that the foregoing and other changes in from and 
details can be made therein without departing from the spirit and scope of 
the invention.