IC card which displays embossed information to prevent counterfeiting

The portable memory medium of the invention has a memory, for storing the predetermined information which is embossed on its surface, and a CPU. When a read instruction is supplied from a portable memory medium handling system externally connected to the portable memory medium, the CPU reads out the predetermined information stored in the memory, and supplies it to the portable memory medium handling system, which then displays the information on a display unit. The operator compares the information displayed on the display unit with the predetermined information embossed on the portable memory medium, and thereby determines the authenticity of the embossed predetermined information.

BACKGROUND OF THE INVENTION 
The present invention relates to a portable memory medium such as a credit 
card. 
Because of their convenience and security, credit cards are now widely used 
for settling a wide variety of transactions. Usually, when a transaction 
is carried out using a credit card, information embossed on the credit 
card, i.e., customer information, is transferred onto a slip such as a 
receipt by means of an emboss imprinter at a shop's register, and is kept 
as a record of the transaction. The purchase amount is subsequently 
deducted automatically from the customer's bank account. 
However, a credit card can be easily counterfeited, since it has a 
relatively simple structure. It is therefore possible to obtain someone 
else's customer information, to make a counterfeit credit card by 
embossing the information on a card, and to use the card illegally. As a 
result, the amount of purchase is withdrawn from a bank account designated 
by the information embossed on the counterfeit credit card. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a portable memory 
medium which can be protected against being illegally used by 
counterfeiting of the customer information embossed thereon. 
In order to achieve the above object, a portable memory medium of the 
present invention, which has predetermined information embossed on its 
surface, comprises display means, storage means for storing the 
predetermined information, means for producing a signal indicating a read 
operation of the predetermined information stored in the storage means, 
and control means for reading out the predetermined information, in 
response to the signal indicating the read operation, and for displaying 
the readout predetermined information on the display means. 
The portable memory medium of the present invention has a memory for 
storing information embossed on the card surface, and output means for 
outputting the customer information stored in the memory, in response to 
an input instruction. As a result, the authenticity of the customer 
information can be determined by comparing the information embossed on the 
card surface with the information stored in the memory.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 shows the outer appearance of credit card 1 according to a first 
embodiment of the portable memory medium of the present invention. Card 
main body 2 is made of, e.g., a thin rectangular plastic plate. Belt-like 
magnetic stripe 3 is formed on one edge surface of main body 2 to extend 
in the longitudinal direction of card 1. Information about the owner of 
card 1 and so on is magnetically stored in stripe 3. Identification 
information 4 about the card owner, e.g., code and name of the card owner 
and the valid date of card 1, is embossed on the surface of main body 2. 
Contactor 5 is also provided on the surface of main body 2. Contactor 5 is 
electrically connected with an integrated circuit (IC) buried in main body 
2 and serves as an input/output terminal to obtain electrical contact with 
a card reader/writer (not shown). 
FIG. 2 shows the schematic arrangement of credit card 1 shown in FIG. 1. 
More specifically, the circuitry of credit card 1 consists of contactor 5, 
central processing unit (CPU) 11 connected to contactor 5, and data and 
program memories 12 and 13 connected to CPU 11. CPU 11 and data and 
program memories 12 and 13 are constituted by a single chip 14. A chip 
such as an 8-bit microprocessor HD65901 available from Hitachi Ltd. can be 
used. The chip is buried in card main body 2. Data memory 12 comprises, 
e.g., an electrically erasable programmable read only memory (EEPROM). 
Memory 12 stores embossed information 4 and transaction data processed by 
CPU 11. Program memory 13 comprises, e.g., a mask ROM and stores the 
control program of CPU 11. 
FIG. 3 is a block diagram showing the arrangement of a card handling system 
for credit card 1 shown in FIG. 1. Card handling system 20 consists of 
card reader/writer 21 having an emboss imprint function, keyboard 22, CRT 
display unit 23, and CPU 24 for controlling these components. 
The operation when credit card 1 of the above embodiment and card handling 
system 20 are used will be described with reference to the flow charts of 
FIGS. 6A through 6C. FIGS. 6A through 6C schematically show the sequence 3 
for using card 1 at a shop to purchase articles and, more specifically, 
show the operation sequence performed by the card owner, the operation 
sequence performed by the operator at the shop, and the operation content 
of card handling system 20. Assume that the card owner purchases articles 
at a shop and uses credit card 1 in place of paying in cash. The card 
owner takes the articles to the register, and submits his card 1 to the 
operator together with the articles (step 32). The operator inserts the 
received card 1 in card reader/writer 21 of card handling system 20 (step 
34), and inputs an instruction signal through keyboard 22 to output 
embossed information (step 36). The input instruction signal is supplied 
from CPU 24 to CPU 11 in card 1 via reader/writer 21 (step 38). CPU 11 
reads out the embossed information from data memory 12 (step 40), and 
sends the readout embossed information to CPU 24 via reader/writer 21 
(step 42). CPU 24 displays the embossed information sent from card 1 on 
CRT display unit 23 (step 44) and discharges card 1 from reader/writer 21 
(step 46). In this case, the operator collates the content of the embossed 
information displayed on display unit 23 with the content of the embossed 
information on card 1 (step 48) to determine whether they coincide. If YES 
in step 48, the operator identifies the card user as the legal card owner, 
reinserts card 1 in reader/writer 21 (step 50), and inputs a slip issue 
instruction from keyboard 22. As a result, CPU 24 actuates the emboss 
imprint function of reader/writer 21, and issues a slip to which embossed 
information on card 1 is transferred (step 52). The card owner receivese 
the articles and card 1 (step 54), and finishes shopping. However, if NO 
in step 48, the card user cannot purchase any article using card 1. 
In this manner, embossed information 4 on credit card 1 is stored in data 
memory 12 of card 1. When card 1 is used, the stored embossed information 
is read out and displayed. Therefore, authenticity of the embossed 
information can be determined by checking whether the displayed embossed 
information coincides with the embossed information on card 1. As a 
result, illegal use of card 1 can be prevented. 
Card handling system 20 can have a PIN collation function in order to 
prevent embossed information stored in data memory 12 from being easily 
externally read out or being easily changed. For example, a PIN (collation 
information) of the card owner is stored in advance in data memory 12. 
When credit card 1 is used, the PIN of the card owner is input from 
keyboard 22 in order to send it to CPU 11 from CPU 24. CPU 11 sends the 
PIN to data memory 12. The sent PIN is collated with the PIN prestored in 
data memory 12 by CPU 11. The embossed information is read out from data 
memory 12 when the two PINs coincide. 
A second embodiment of the present information will be described with 
reference to FIGS. 4A and 4B. The same reference numerals denote the same 
parts as in the first embodiment and a detailed description thereof is 
omitted. Only parts different from the first embodiment will be described 
in detail. 
FIGS. 4A and 4B show the outer appearance of credit card 1. As shown in 
FIG. 4A, embossed information 4 is formed and contactor 5 is provided on 
the front surface of card main body 2. As shown in FIG. 4B, keyboard 6, 
liquid crystal display unit 7, and solar cell 8 are provided on the rear 
surface of main body 2. Keyboard 6 has collation key 9 as well as ten keys 
and function keys. 
FIG. 5 schematically shows the circuit configuration of credit card 1 shown 
in FIGS. 4A and 4B. Card 1 consists of CPU 11, data and program memories 
12 and 13, and display driver 15, and is constituted by 1-chip IC 14. 
1-chip IC 14 is buried in card main body 2 and receives operation power 
from solar cell 8. In the second embodiment, data memory 12 stores the PIN 
(collation information) of the card owner and a balance for shipping (a 
predetermined amount of money) as well as the embossed information formed 
on the surface of main body 2. 
The operation of the second embodiment having the above arrangement will be 
described with reference again to FIG. 6. Assume that a card owner wishes 
to purchase articles at a shop by using credit card 1 instead of paying in 
cash, the same as in the first embodiment. The card owner brings the 
articles to the register, takes out his card 1, inputs his PIN through 
keyboard 6, and depresses collation key 9. CPU 11 performs collation to 
check whether the input PIN coincides with that stored in data memory 12. 
If the two PINs coincide, CPU 11 sends a message indicating a coincidence 
on liquid crystal display unit 7, reads out the embossed information from 
memory 12, and displays the readout embossed information on display unit 
7. In this case, CPU 11 alternately displays the message indicating the 
collation result and the embossed information are displayed. The operator 
looks at the message displayed on display unit 7 to check that the PINs 
coincide, and collates the content of the embossed information displayed 
on display unit 7 with that of the embossed information on card 1. 
When a coincidence is confirmed, the card owner inputs the total price for 
the articles through keyboard 6, and depresses collation key 9. CPU 11 
checks whether the input amount of money is smaller than the balance for 
shopping in data memory 12. If the input amount of money is smaller than 
the balance, CPU 11 subtracts the total price for the articles from the 
balance and stores the subtraction result as a new balance for shopping in 
data memory 12. Subsequently, based on the input PIN and the total price, 
CPU 11 executes operation processing in accordance with a predetermined 
encrypting algorithm in order to calculate specific encrypted data (sales 
approval number) (step 56 of FIG. 6B) and displays the calculated 
encrypted data on liquid crystal display unit 7 (step 58). Then, the card 
owner submits credit card 1 on which the encrypted data is displayed to 
the operator of the register (step 60). The operator writes down the 
encrypted data displayed on display unti 7 on a memo sheet or the like 
(step 62), and inserts card 1 in an emboss imprinter (not shown) (step 
64), thereby issuing a slip to which the embossed information on card 1 is 
transferred (step 66). The operator writes the written encrypted data on 
the issued slip (step 68). The encrypted data written on the slip is used 
as collation data if a trouble occurs on a later day. The user then 
receives his goods and credit card (step 70). 
In the second embodiment, since the readout embossed information is 
displayed on credit card 1, collation of the embossed information can be 
performed on card 1, thereby allowing easy collation. 
In the first and second embodiments, data and program memories are 
constituted by a 1-chip IC. However, they can be constituted by a 
plurality of IC chips. 
The display means is not limited to a liquid crystal display unit but can 
be another display medium such as a plasma or EL (Electro Luminescence) 
display. The cell is not limited to the solar cell but can be a lithium 
cell and so on. 
In the above embodiments, a credit card is used as the portable memory 
medium. However, the present invention is not limted to a card-like memory 
medium but can be applied to a block- or pencil-like memory medium. 
The circut configuration of the portable memory medium can be modified in 
various ways in a manner normally done by a person skilled in the art.