1. Field of the Invention
The present invention relates to a PC Card input/output device for use with PC Cards and a PC Card connector, which are used for writing and reading data to and from a PC Card containing a number of storage elements, and, more particularly, to improvements in the convenience of PC Cards.
2. Description of the Prior Art
Referring next to FIG. 7, there is illustrated an external view of the outward appearance of a PC Card. In the figure, reference numeral 1 denotes a PC Card, 6 denotes a female connector formed on the front side of the PC Card 1 which is to be in the lead when inserted into a PC Card socket, and comprised of a plurality of female connecting terminals, 7 denotes a notch formed on the right (or upper) side and one lateral side of the PC Card 1 and extending along the length of the PC Card 1 from the front side of the PC Card 1 and, and 8 denotes a guide slit formed on the other lateral side of the PC Card 1 and extending along the length of the PC Card 1 from the front side of PC Card 1.
Referring next to FIG. 8, there is illustrated a block diagram showing the structure of a prior art input/output device for use with PC Cards and a peripheral circuit. In the figure, reference numeral 2 denotes a PC Card connecter into which the PC Card 1 gets inserted, having a male connector which is electrically connected with the female connector 6 of the PC Card 1, and 3 denotes an internal circuit which can be electrically connected with the PC Card 1 by way of the PC Card connector 2. Referring next to FIG. 9, there is illustrated a perspective view showing the structure of the prior art PC Card connector 2 shown in FIG. 8. In FIG. 9, reference numeral 9 denotes a socket portion into which the PC Card 1 gets inserted so that the female connector 6 of the PC Card 1 is electrically connected to the PC Card connector 2, 10 denotes a plurality of male connecting terminals projected from an inner wall of the PC Card connector 2 at the back of the socket 9, 11 denotes a guide rail which can be engaged with the guide slit 8 of the PC Card 1 so as to guide the guide slit 8 when the PC Card 1 gets inserted into the socket portion 9, and 19 denotes an insertion blocking member which can be engaged with the notch 7 of the PC Card 1 when the PC Card 1 gets inserted into the socket so as to prevent the PC Card 1 from being pressed against the inner wall of the PC Card connector 2 after the plurality of female connecting terminals of the PC Card 1 are surely engaged with the plurality of male connecting terminals 10 of the PC Card connector 2, respectively.
In operation, the PC Card 1 gets inserted into the socket portion 9 with the upper side of the PC Card 1 pointing upwards while the guide slit 8 of the PC Card 1 is engaged with the guide rail 11. Once the PC Card 1 is inserted into the socket portion 9 as far forward as possible until the notch 7 is engaged with the insertion blocking member 19, the PC Card 1 is stopped and the plurality of female connecting terminals of the connector 6 of the PC Card 1 are brought into contact with and therefore electrically connected to the plurality of male connecting terminals 10 of the PC Card connector 2, respectively.
As a result, the internal circuit 3 is connected to the plurality of female connecting terminals of the PC Card 1 by way of the PC Card connector 2, so that the PC Card 1 can furnish and receive data to and from the internal circuit 3 in response to reading and writing requests from the internal circuit 3.
It is clear from FIG. 9 that the PC Card 1 cannot get inserted into the socket portion 9 with the reverse or lower side of the PC Card 1 pointing upwards because the front edge of the PC Card 1 is brought into contact with the insertion blocking member 19 and therefore the insertion of the PC Card 1 is stopped on the way to the plurality of male connecting terminals 10. The plurality of female connecting terminals of the PC Card 1 thus cannot reach the plurality of male connecting terminals 10 of the PC Card connector 2.
As previously explained, when utilizing a PC Card 1 and a PC Card connector 2 which comply with the PC Card Standard, the PC Card 1 can get inserted into the socket portion 9 of the PC Card connector 2 only when making the upper side of the PC Card 1 point upwards. As a result, the PC Card 1 can be connected to the internal circuit while a certain connection between the PC Card 1 and the internal circuit is established.
While the combination of the above-mentioned prior art PC Card and the PC Card connector can prevent the user from inserting the PC Card while mistaking the lower side of the PC Card for the upper side of the PC Card, and therefore prevent improper electrical connections between the PC Card and the PC Card connector, there is a problem in that every time the user does an improper insertion the user has to insert the PC Card again by turning the PC Card upside down, resulting in reduction in the convenience of the PC Card. Especially, when the PC Card connecter is disposed such that its insertion opening is running longitudinally, it is difficult for the user to determine in which direction the upper and lower sides of the PC Card should be oriented, resulting in substantial reduction in the convenience of the PC Card.
Japanese Patent Application Laying Open (KOKAI) No. 6-155974 discloses an improved prior art PC Card to solve the above problem. Referring next to FIG. 10, there is illustrated a perspective view showing the outward appearance of the PC Card as disclosed in the reference. In FIG. 10, reference numeral 20 denotes a switch disposed on one lateral side of the improved PC Card 100 which is opposite to the other lateral side on which a notch 7 is formed. The switch 20 can slide on the lateral side of the PC Card 100 opposite in direction to the travel of the PC Card 100. The switch 20 extends such that its free end reaches the front side of the PC Card 100 which is to be in the lead when the PC Card 100 gets inserted into a PC Card socket. Reference numeral 21 denotes a connection switching unit connected between the female connector 6 and a memory disposed inside the PC Card 100, responsive to a switching signal from the switch 20, for changing the connection between the plurality of female connecting terminals of the PC Card 100 and the pins of the built-in memory. To be more specific, the connection switching unit 21 performs a switching in such a manner that the connecting target with which each of the pins of the built-in memory is to be connected is switched from one female connecting terminal of the PC Card 100 to another female connecting terminal symmetric to the former female connecting terminal with respect to the center C of the front side of the PC Card 100.
When the user inserts the PC Card 100 into the PC Card connector with the upper side of the PC Card pointing upwards, the PC Card 100 is properly mounted into the PC Card connector, like the above-mentioned prior art PC Card as shown in FIG. 9. On the other hand, when the user inserts the PC Card 100 into the PC Card connector with the reverse side of the PC Card pointing upwards, the free end of the switch 20 is brought into contact with the insertion blocking member 19. When the user further pushes the PC Card 100 into the back of the socket, the female connector 6 of the PC Card 100 is electrically connected to the PC Card connector 2. In the PC Card 100, the switch 20 then generates a switching signal in response to the travel of the switch 20, with the result that the connection switching unit 20 changes the connection between the plurality of female connecting terminals and the pins of the built-in memory in such a manner that the connecting target with which each of the pins of the built-in memory is to be connected is switched from one female connecting terminal to another female connecting terminal symmetric to the former female connecting terminal with respect to the center C of the front side of the PC Card 100.
Accordingly, even though such the prior art PC Card 100 is inserted improperly into a PC Card socket with the reverse side of the PC Card 100 pointing upwards, the improved PC Card 100 can be electrically connected to the PC Card connector while the connection between the built-in memory and the internal circuit 3 by way of the female connector 6 and PC Card connector 2 is established in the same manner as the case where the PC card 100 is properly inserted into the PC Card socket with the right side of the PC Card 100 pointing upwards because the electrical coupling between the plurality of female connecting terminals of the female connector 6 of the PC card 100 and the plurality of male connecting terminals 10 of the PC Card connector 2 has been changed and the connection between the plurality of female connection terminals of the PC Card 100 and the pins of the built-in memory has been changed similarly. Thus the PC Card 100 can receive and furnish data from and to the internal circuit 3 reliably in response to reading and writing requests from the internal circuit 3 regardless of how the PC Card 100 inserted into the PC Card socket is oriented.
While the improved PC Card enabling the improper insertion offers an advantage of allowing an internal circuit to read and write data from and to the PC Card inserted into a PC Card socket regardless of how the PC Card inserted is oriented, it cannot improve the operability of prior art PC Cards which have become widely available and which complies with the PC Card Standard, instead, there is a fear that the introduction of the improved PC Card on the market causes a state of disorder wherein the improved PC Cards enabling the improper insertion coexist with existing prior art PC Cards and therefore users are required to use both the improved PC Cards and prior art PC Cards each in its proper way, resulting in reduction in the general convenience of PC Cards.