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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a non-contact integrated circuit card and,
more specifically, to a non-contact integrated circuit card that
incorporates a battery as a power supply.
2. Description of the Related Art
The construction of a conventional non-contact integrated circuit card is
shown in FIG. 6. A CPU 1 for processing data and for controlling the
operation of the card is connected with a ROM 2 and a RAM 3 via a bus 8.
The ROM 2 is provided for storing programs, while the RAM 3 is provided
for storing data. The bus 8 is connected with an input-output (I/O)
control circuit 5 for controlling the inputting of data from and
outputting of data to an external apparatus (not shown). The I/O control
circuit 5 is connected, via a modulation/demodulation circuit 6, with an
antenna 7. The card also includes a battery 4 incorporated therein for
supplying electrical energy to the above-described electric circuits.
With such a card, when a signal to be input, which is in the form of an
electromagnetic wave, is received from an external apparatus by the
antenna 7, the signal is digitized by the modulation/demodulation circuit
6. Thereafter, the signal is input to the CPU 1 via the I/O control
circuit 5. The CPU 1 processes the input signal in accordance with the
programs stored in the ROM 2, and stores data in the RAM 3 in accordance
with necessity. Data to be output in response to an external apparatus,
such as the results of processing, are supplied, via the I/O control
circuit 5, to the modulation/demodulation circuit 6, in which the data are
converted into analog equivalents. Thereafter, the data are transmitted as
electromagnetic waves via the antenna 7 to the external apparatus.
In order that the card can receive a signal from an external apparatus and
process the input signal, each of the electric circuits incorporated in
the card must always be supplied with electric current from the battery 4
so that the card stands by in its state of being capable of receiving.
However, after the battery 4 is incorporated in the card during the
manufacturing of the card, the flow of electric current from the battery 4
continues even before the shipment of the card. Therefore, the energy
produced by the battery 4 is rapidly consumed.
Because of the shape of the card, the battery 4 incorporated therein must
be very thin. For this reason, it is impossible to incorporate a battery
having a large current capacity. Furthermore, since the outer periphery of
the card is normally enclosed by an outer cover made of plastic or the
like, it is impossible to replace the battery 4 with a new battery.
Consequently, the conventional card has a problem in that the life of the
battery 4 after the card is placed on the market, that is, the period
during which the card is usable, is short. Another problem is that the
durability of the batteries of the cards placed on the market varies
depending on the length of the period from the incorporation of the
battery 4 in the card to the shipment of the card.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a non-contact
card that has, when placed on the market, a long usable period.
In order to achieve the above object, according to the present invention,
there is provided a non-contact card comprising: data transmitting and
receiving means for transmitting and receiving data; a data processing
means, connected with the data transmitting and receiving means; a clock
generating means, for processing data for generating a clock signal and
for supplying the clock signal to the data processing means; a battery for
supplying electrical energy to the data transmitting and receiving means,
the data processing means and the clock generating means; and a clock
stopping means for stopping the generation of the clock signal by the
clock generating means upon inputting a clock stop signal from outside of
the card.
According to the present invention, the clock stopping means stops, in
response to a clock stop signal input from an external circuit, the
operation of the clock generating means, thereby suspending the
consumption of energy produced by the battery.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing the construction of a non-contact card
according to one embodiment of the present invention;
FIG. 2 is a block diagram showing the internal construction of a clock
generating circuit of the card and a clock stopping circuit of the same;
FIGS. 3 through 5 are views showing different methods of inputting a clock
stop signal; and
FIG. 6 is a block diagram showing the construction of a conventional
non-contact card.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention will now be described
with reference to the accompanying drawings.
Referring to FIG. 1, a non-contact integrated circuit card 10 according to
one embodiment of the present invention has a CPU 11 to which a bus 18 is
connected. The bus 18 is also connected with a ROM 12 for storing programs
in accordance with which the operation of the CPU 11 is controlled, a RAM
13 for storing data, and an input-output (I/O) control circuit 15 for
controlling the inputting of data from and outputting of data to an
external apparatus (not shown). The I/O control circuit 15 is connected
with a modulation/demodulation circuit 16 which is in turn connected with
an antenna 17.
The CPU 11 is connected with a clock generating circuit 19 for supplying a
clock signal to the CPU 11, and the clock generating circuit 19 is
connected with a clock stopping circuit 20 for stopping, in response to a
clock stop signal applied to an input terminal 35 of to the card 10, the
operation of the clock generating circuit 19. The card 10 also has a
battery 14 including a power terminal 8 and a ground terminal incorporated
therein for supplying electrical energy to the electric circuits within
the card 10.
The modulation/demodulation circuit 16 and an antenna 17 comprise data
transmitting and receiving means, the CPU 11 comprises a data processing
means, the clock generating circuit 19 comprises a clock generating means,
and the clock stopping circuit 20 comprises a clock stopping means.
FIG. 2 shows the internal construction of the clock generating circuit 19
and the clock stopping circuit 20. The output terminal Q of a first
flip-flop 21 is connected, via a first AND circuit 22, a first NAND
circuit 23 and 1/2 frequency-dividers 24 and 25, with a second NAND
circuit 26. The NAND circuit 26 is connected to the CPU 11. The output of
the 1/2 frequency-divider 24 is also connected, via a 1/8
frequency-divider 27, a second AND circuit 28, a pre-scaler 29 and a timer
30, with the set terminal S of a second flip-flop 31. The output terminal
Q of the second flip-flop 31 is connected, via a third AND circuit 32,
with the second NAND circuit 26. The first NAND circuit 23 is connected
with a resonator 33. The first NAND circuit 23 and the resonator 33
constitute a resonant circuit 34.
Next, the operation of the embodiment will be described. In the process for
manufacturing the card, the individual circuits, shown in FIG. 1, of the
non-contact card 10 are fabricated, and the battery 14 is mounted on the
card 10. Thereafter, product tests are performed as required. Prior to the
tests, regarding the construction shown in FIG. 2, a reset signal is input
to the set terminal S of the first flip-flop 21 and the reset terminal R
of the second flip-flop 31. Further, a clock stop signal at a high ("H")
level is input to each of the first and third AND circuits 22 and 32. The
first flip-flop 21, whose set terminal S has input a reset signal,
outputs, from its output terminal Q, an oscillation permit signal at "H"
level to the first NAND circuit 23 via the first AND circuit 22. This
output starts oscillation of the resonant circuit 34. The output of the
resonant circuit 34 has its frequency reduced to 1/4 by the 1/2
frequency-dividers 24 and 25, and then is output as an internal clock from
the second NAND circuit 26. Actually, in order to provide a delay until
the oscillation waveform stabilizes, the 1/8 frequency-divider 27, the
pre-scaler 29, timer 30 and the second flip-flop 31 cooperate with each
other in such a manner that an internal clock is output after a
predetermined period passes from the start of oscillation of the resonant
circuit 34, i.e., until overflow of the timer 30.
The internal clock signal generated in this way renders the CPU 11
operable. In this state, product tests are performed in order to check
whether the non-contact card 10 operates normally.
When the product tests have been completed, a clock stop signal at a low
("L") level is input to each of the first and third AND circuits 22 and
32. This input makes the AND circuit 22 prevent the oscillation permit
signal from the first flip-flop 21 from being input to the first NAND
circuit 23. Accordingly, the oscillation of the resonant circuit 34 stops.
The inputting of the L-level clock stop signal to the third AND circuit 32
makes the AND circuit 32 prevent the output from the second flip-flop 31
from being input to the second NAND circuit 26. Thus, the generation of
the internal clock from the NAND circuit 26 stops. As a result, the
operation of the CPU 11 stops and, accordingly, the entire function of the
card 10 stops so that the consumption of energy produced by the battery 14
is suspended until the internal clock signal is again generated.
In this way, after product tests, the consumption of electrical energy
produced by the battery 14 is suspended until shipment. Therefore, it is
possible to avoid any consumption of energy produced by the battery 14
during the manufacturing process, and hence, to increase and stabilize the
usable period of the non-contact card 10 after it is placed on the market.
The generation of the internal clock signal may again be started
immediately before the shipment of the card 10 so that the card 10 is
shipped while in an operating state. Alternatively, the non-contact card
10 may be shipped while the generation of the internal clock is stopped,
and the generation of the internal clock may be re-started by the user
immediately before use is started.
During use, the non-contact integrated circuit card 10 transmits data to
and receives data from an external apparatus in a manner similar to that
of the conventional card shown in FIG. 6. That is, when a signal to be
input, which is in the form of an electromagnetic wave, is received from
an external apparatus (not shown) by the antenna 17, the input signal is
digitized by the modulation/demodulation circuit 16. Thereafter, the
signal is input to the CPU 11 via the I/O control circuit 15. The CPU 11
processes the input signal in accordance with the programs stored in the
ROM 12, and stores data in the RAM 13 in accordance with necessity. Data
to be output in response to an external apparatus, such as the results of
the processing, are supplied, via the I/O control circuit 15, to the
modulation/demodulation circuit 16, in which the data are converted into
analog equivalents. Thereafter, the data are transmitted as
electromagnetic waves from the antenna 17 to the external apparatus.
A clock stop signal is input to the AND circuits 22 and 32 shown in FIG. 2
in, for instance, the following manner. As shown in FIG. 3, an outer cover
of a sealed card 40 is formed with a pair of insertion holes 41a and 41b.
A pair of leg portions 42a and 42b of a conductive member 42 are inserted
into the holes 41a and 41b, respectively. One of the insertion holes 41 a
is formed at a position corresponding to one of the respective input
terminals of the first and third AND circuits 22 and 32 shown in FIG. 2,
and the other insertion hole 41b is formed at a position corresponding to
a grounding line (not shown). When the leg portions 42a and 42b of the
conductive member 42 are inserted and brought into contact with the input
terminals of the AND circuits 22 and 32, and the grounding line,
respectively, a clock stop signal at "L" level is input, through the
conductive member 42, to the AND circuits 22 and 32. With this method, the
generation of the internal clock can be easily controlled even after the
card 40 is sealed. That is, after the product tests, the conductive member
42 is mounted on the card 40, and, thereafter, the member 42 is removed
from the card 40 immediately before shipment or use.
Alternatively, the clock stop signal may be input by, as shown in FIG. 4,
forming insertion holes 51a and 51b at a side portion of a card, and
inserting therein leg portions 52a and 52b of a conductive member 52.
In still another alternative, a substrate 60 on which the above-described
circuits are mounted may have a terminal 61 formed in a part thereof, the
terminal 61 being connected with one of the respective input terminals of
the first and third AND circuits 22 and 32 shown in FIG. 2. When a
grounded contact member (not shown) such as a grounded clip or the like is
brought into contact with the terminal 61, the terminal 61 is brought to
the ground level.
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