Patent
1994-04-05
1998-03-03
Moore, David M.
395465, 395438, 395405, 395241, 395427, 39542109, 395402, G06F 1200, G06F 926, G06F 932
Patent
active
057245452
DESCRIPTION:
BRIEF SUMMARY
CROSS REFERENCE TO RELATED APPLICATIONS
This application is the U.S. national phase of PCT application PCT/FR91/00785 filed 7 Oct. 1991.
FIELD OF THE INVENTION
The present invention relates generally to a memory card intended for storing information and having the size of a credit card.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an edge view of a prior-art first type of memory card;
FIG. 2 is a perspective view of a prior-art second type of memory card;
FIG. 3 is a schematic diagram illustrating the instant invention; and
FIG. 4 a top view showing the layout of the external contacts of the card according to the invention.
BACKGROUND OF THE INVENTION
The telephone card, a so-called telecard, is known which actually has in a silicon chip a wired circuit permitting the storage of several memory registers corresponding to prepayed telephone units.
Another memory card, called a chip card, is now known which is based essentially on a microprocessor chip (CPU) which gives security or confidentiality to a limited amount of information representing either financial information (charge cards), personal information (medical records, university records), codes for access to certain locations, or even a combination of this information. Access to the information is gained by a serial connection through a single conductor through the microprocessor with the help of a complex set of instructions for transmission.
The use of microprocessor on the silicon chip takes up space and does not permit the addition of a very large memory capacity.
FIG. 1 shows the two types of cards described above. They employ for the elements that use them an array of ISO-type connectors (standard ISO 7816-2) whose number is reduced to eight. This allows the easy manufacture of these cards simply by adhering and connecting the chip 1 to the back of a small contact unit 2 made by depositing conductors on a film and then installing this unit into a seat 3 formed to this end in the 0.76 mm thick plastic of the card 4.
This embodiment is very economical and can be distributed widely.
Another known type of memory card consists of a particular treatment of one or more standard memory elements connected into a rigid printed circuit to which is also connected a connector that is then inserted into a plastic support of credit-card size. The connector has a great many address-line contacts, the number increasing with the memory of the card.
This latter type of memory card is above all used in printers as support for supplemental-characters sets or in pocket computers to replace the magnetic disks which are usually mounted in portable computers.
FIG. 2 shows the construction of this type of card. The chips 5a forming the memory are secured as is (chip-on-board technology) or in a casing 5b and are connected to the traces of the printed circuit 6 usually formed of epoxied fiberglass. Data transmission takes place through a connector normally fitted at, the end of the printed circuit and formed either by contacts 7 formed by conductive deposits directly on the printed circuit or by a collection of mechanical connections 8 mounted beforehand in a plastic housing 9 which is mounted at the edge of the printed circuit, the contacts being soldered to the traces of the circuit.
The printed circuit is then sandwiched between two plastic housing halves 10 to form the memory card.
This technology is expensive with respect to the other system described above and does not allow this type of memory card to be distributed more widely than in the professional world.
The main reasons necessitating this embodiment are: surface, a significant amount of space along one edge of the card.
In fact the amount of memory provided in this type of memory card is normally from 256 kilobytes to several megabytes. This memory size requires for random addressing at least 18 address lines which requires, in addition to eight information lines and four or five selection lines for read/write, ground, and power, forming part of, at least 32 electrical-connection lines (for 256 kilob
REFERENCES:
patent: 5241662 (1993-08-01), Maniwa et al.
Dubno Herbert
Moore David M.
Nguyen Than V.
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