Registers – Records – Fluorescent – phosphorescent – radiation emitting
Reexamination Certificate
1999-10-01
2001-03-20
Hajec, Donald (Department: 2876)
Registers
Records
Fluorescent, phosphorescent, radiation emitting
C235S380000, C235S492000
Reexamination Certificate
active
06202932
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a portable information storage and processing module which is connected to a host unit and a method of exchanging information between the module and the host unit. The invention relates especially to a so called ‘smart card’ which consists of an integrated circuit chip attached to a plastic card and contact areas on the surface of the plastic card to provide the necessary energy supply to the chip and data transmission to and from the chip.
BACKGROUND OF THE INVENTION
The standards ISO 7816 and ETS 300 608 (ETSI, code GSM 11.11) define the smart card solutions for the world wide used Global System for Mobile Communications System (GSM) by which information storing is made permanently protected.
FIG. 1
presents a typical ISO 7816 smart card, 85×53×0.8 mm in size, provided with the eight electrical contacts
15
to the integrated circuit chip inside the card. It also shows one way to encase the encapsulate smart card chip
12
. Firstly, the card is laminated from the bottom
10
and middle
11
to which a stepped cavity is produced for the integrated circuit chip
12
. Then, the golden or gold plated surfaces
13
are laminated or grown over the stepped side walls and they also form the contact areas
15
which are visible on the surface of the smart card.
According to one manufacturing process the integrated circuit chip
12
of the smart card
1
is glued to the bottom of the cavity and then bonded with gold wire
14
with known methods to the golden contact areas
15
located at the side wail of the cavity. After this the cavity is filled with hardening plastic material so that the contact areas
15
remain visible on the top. According to the ISO 7815 standard the distance between the centre points of the contact areas
15
must be 7.5 mm which means that the width of the integrated circuit chip in the direction B-B′ in
FIG. 1
can be at most 4 mm.
Other methods for attaching the integrated circuit chip to the smart card are also known. For example, in
FIG. 2
a circuit board
20
is used as the substrate and as a contact surface for the integrated circuit chip
12
. This circuit board is then embedded into a suitable card base
21
of pre-defined size to form the desired smart card. This structure demands the use of a filling material
22
which also fills the space between the integrated circuit chip
12
and the circuit board
20
.
FIG. 3
represent a widely used solution to connect the smart card
30
to a host unit. The contact areas
31
of the smart card
30
are brought in to a mechanical contact with the springs
32
which are electrically connected to the host unit via e.g. a circuit board
33
which is supported by a mechanical frame
34
. The frame supports the smart card from the contact side mechanically and the springs
32
press the contact areas
31
with their spring force and an electric contact is produced. According to standards ISO 7816 and ETSI 300 608 the spring force should be less than 0.5 N per each contact.
Previously described solutions have their own advantages and disadvantages. A larger semiconductor chip can be attached to the solution in
FIG. 2
than to the solution in
FIG. 1
, but the costs will rise because of the extra circuit board and costly manufacturing and therefore it is significantly more expensive. There are also other restrictions which limit the present use of smart cards, mostly because they deploy the previously described electric contacts with the host unit. This limits the use of for example the operating voltage to 5 or 3 volts, clock frequency etc. In addition, the electric contact surfaces of the smart card are exposed to touching, rubbing and especially to electrostatic discharge.
Because a reliable electric contact must be accomplished between the smart card and the host unit with the allowed less than 0.5 N force, the structure in
FIG. 3
must be very stable and the contact surfaces
31
and
32
must be gold or gold plated. As is known only gold metal can with stand the typical conditions where the smart card is used without oxidizing etc. There fore each contact with the host unit also becomes an extra cost in the manufacturing process.
Previously described solutions use electrical contact between the host unit and the smart card, but also other methods have been introduced. In the publications U.S. Pat. No. 5,206,495, EP 0466 949 A1, DE 42 40 238A1, DE 43 10 334 A1 and U.S. Pat. No. 4,692,604 the contact between the smart card and the host unit is based on a magnetic field through a coil inside the smart card. In the publications EP 0 534 559 A1 and DE 41 38 131 A1 the data transfer is based on electromagnetic radiation in the kHz area.
The closest solution compared to this is the one in GB 2 278085 where both energy and data are transferred between the host and the smart card through optical radiation. The method is however limited to separate photo-voltaic cells which are located at the top of the integrated circuit chip and which convert optical energy into electric current, while the defined current is conducted into the integrated circuit chip through another contact. The optical radiation is focused to the smart card through collimators. The data transfer is suggested to happen with known methods of amplitude modulation. How ever, the application does not include any practical solutions for data transfer and none what so ever for data transfer from the smart card to the host unit. The application also doesn't include any examples of transferring the clock frequency to the smart cards integrated circuit chip. It also leaves open with which values of the parameters the solution is able to work.
This invention has a purpose to present a method with which an information storage and/or processing unit, typically a integrated circuit chip, in a portable device gets energy and the data circuitry it needs without any electric circuitry to the host unit. Then it would be possible to have a portable device which has no conductors between separate parts. Using this method it should be possible to transfer the necessary clock frequency to the integrated circuit chip using optical radiation and to transfer information between the smart card and the host unit at bit-rates up to the said clock frequency.
These goals should be reached with ways that are described in the following independent patent claims.
SUMMARY OF THE INVENTION
In the following we assume that a portable unit consists of a integrated circuit chip, a substrate supporting the chip and protecting structures covering the chip :which we altogether call a smart card. A host unit feeds the smart card its energy and clock frequency and receives data from the smart card. The energy supply and data transfer are possible because of the proximity of the host unit and the smart in such a way that energy is transferred as optical radiation, clock frequency is transferred as energy supply's periodic variation, data is transferred to the smart card as modulation of the clock frequency and from the smart card to the host unit with electromagnetic proximity connection directly from the surface of the integrated circuit chip.
Other methods for the data transfer from the card to the host can also be either capacitive proximity connection or optical reflection modulation in which an area on the surface of the card, pn-surface, changes its reflection coefficient according to the data and in which the host unit notices the changes in the reflection coefficient. In this way the energy consumption in the data transfer from the card to the host is minimal.
The advantages of this invention are amongst other things independent of the operating voltage and reliable and non-contact connection between the card and the host. Also a smart card using this technique would be cheap to manufacture, simple and reliable, and it wouldn't set any limits to the size or form of the semiconductor chip inside the smart card.
REFERENCES:
patent: 3971916 (1976-07-01), Moreno
patent: 4742573 (1988-05-01), Popovic
pa
Hajec Donald
Taylor Larry D
Young & Thompson
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