Note: Descriptions are shown in the official language in which they were submitted.
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DEVICE AND METHOD FOR COMMUNICATION
Field of the Invention
The present invention relates to electronic trans-
mission of handwritten information.
Background Art
The amount of information transmitted electronical-
ly has increased in recent years. Most of the informa-
tion transmitted electronically has been generated by
means of a computer. There is, however, a great need for
electronically transmitting information that has been
generated in some other way than by means of computers.
For instance, there is a need for transmitting handwrit-
ten information in connection with the filling-in of a
form. A further example when there is a need for trans-
mitting handwritten information involves advertisements
in newspapers. Advertisements in newspapers sometimes
have a writing area for handwritten information and a fax
number to which the advertisement can be sent.
For a long time the only possibility of sending
handwritten information was to use a fax machine. An
alternative is to use a scanner for converting the infor-
mation to a digital image which can then be transmitted
via a computer communication link or via the telephone
network. US Patent 5,852,434 discloses a method for
entering handwritten information by means of a pen and a
base with a coordinate pattern. When writing on the base,
the pen records the movement and stores it as positions.
Independently of how the information is entered, a
manual step is necessary when transmitting the informa-
tion.
There is thus a need for an alternative method and
a device adapted to the method for easier handling when
transmitting handwritten information such as handwritten
text.
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Summary of the Invention
An object of the present invention is to provide a
device for easy recording and transmission of handwritten
information.
A further object of the present invention is to
provide a user unit by means of which handwritten infor-
mation can easily be transmitted to a predetermined
receiver.
Another object of the present invention is to pro-
vide a memory medium with a computer program which can be
used to control a user unit according to the invention.
One more object of the present invention is to pro-
vide a device for easy recording and transmission of
handwritten information, which allows compact storage of
an encryption key.
These objects are achieved by a product, a user
unit, and a storage medium according to the appended
claims.
A product according to the invention for electronic
transmission of handwritten text comprises at least one
writing area intended for the handwritten information and
an address area which indicates an address to which the
handwritten information is to be transmitted. The product
is characterised in that a position-coding pattern in the
form of a plurality of symbols is reproduced in the writ-
ing area, an arbitrary position area of a predetermined
size of the position-coding pattern unambiguously defin-
ing a position on the product, and that the address area
comprises an address-coding pattern with a plurality of
symbols, an arbitrary address portion of a predetermined
size of the address-coding pattern unambiguously defining
part of the address.
The product preferably consists of a sheet of paper
in a newspaper but may also consist of e.g. an informa-
tion board.
Position-coding patterns are per se known from, for
instance, US Patent 5,852,434. By the product containing
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a writing area with a position-coding pattern, it is~pos-
sible to enter information in the writing area by means
of a user unit while at the same time a position sequence
corresponding to the movement of the pen is recorded. As
a result, the handwritten information is recorded while
being written on the sheet of paper. Since the address
area contains an address-coding pattern it is possible to
read the address to which the handwritten information is
to be sent by recording the information by means of a
user unit which is adapted to enter the address-coding
pattern and the position-coding pattern. The position-
coding pattern thus defines a large number of positions.
Each of the positions is associated with different parts
of the writing area.
The size of the position area that is required to
unambiguously determine a position from the position-
coding pattern is advantageously at least the same as
the size of the address area required to unambiguously
determine part of the address from the address-coding
pattern. It is thus possible to adapt a user unit to the
position-coding pattern without taking the address-coding
pattern into consideration.
Said part of the address is advantageously an indi
vidual character. By said address portion of a predeter
mined size of the address-coding pattern unambiguously
defining a character, the decoding operation will be
simple.
It is, of course, within the scope of the invention
that certain characters correspond to a special command.
For instance, a character constitutes information about
how the information is to be transmitted. Thus one char-
acter signifies that the information is to be sent by
electronic mail and another character that the informa-
tion is to be sent by fax.
The address area advantageously contains information
which defines a communication medium which is to be used
for the transmission of the handwritten information. In
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the case where the address area does not contain such
information, a user unit can interpret the information in
the address area and thus establish which communication
medium is to be used. For example, all addresses contain-
s ing the character "@" are interpreted as electronic mail
addresses.
Advantageously the position-coding pattern defines
positions within a partial code area which is part of
a larger virtual code area, the address area containing
information which defines the coordinates for at least
part of the writing area.
The position-coding pattern on different products
codes advantageously different partial code areas. As a
result, a user unit recording the address can deter-
mine which handwritten information is to be sent to the
address. It is also an advantage that a user can write on
a plurality of products in parallel without any risk that
the written information is mixed up. Different companies
can then reserve different partial code areas.
The address-coding pattern advantageously contains a
plurality of sequence portions with symbols, the address
portion which is required to define part of the address
containing sequence portions of a predetermined number
and a predetermined length. By the symbols being arranged
in sequence portions, the recording and interpretation of
the pattern is facilitated.
Each of the sequence portions advantageously com-
prises at least one subsequence of a predetermined length
of a sequence, each subsequence unambiguously defining a
sequence value which corresponds to the position of the
subsequence in the sequence. As a result, the subse-
quences can easily be converted to sequence values.
The difference between the sequence value defined
by a subsequence of a first sequence portion and the
sequence value defined by a subsequence of a second
sequence portion is constant independently of from which
parts of the sequence portions the subsequences are
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selected when the subsequences are fetched from corre-
sponding parts of the sequence portions. By using diffe-
rences between sequence portions, the address-coding pat-
tern will be independent of which parts of the address-
5 coding pattern are recorded. If the sequence portions are
arranged in columns in a matrix, the address-coding pat-
tern will be insensitive to at what height in the columns
the address-coding pattern is recorded.
The difference value which corresponds to the dif-
ference between sequence values from different sequence
portions can be represented as a binary value. A first
part of the binary value represents a character and a
second part of the binary value codes a sequence position
for the sequence portions in the matrix.
By the difference value coding a sequence position,
the recording of the address is facilitated since it is
then possible to record different parts of the address
on different occasions and get the complete address toge-
ther by means of the sequence positions. This results in
robust inputting. It is thus possible to record different
parts of the address-coding pattern on different occa-
sions and put together the entire address by means of the
sequence positions.
The symbols in the address-coding pattern have
advantageously a size different from that of the symbols
in the position-coding pattern. Alternatively the symbols
in the address-coding pattern are arranged with an inter-
space which is different from that of the symbols in
the position-coding pattern. A user unit can thus easily
distinguish the address-coding pattern and the position
coding pattern.
It goes without saying that it is possible for the
two patterns to differ from each other merely by the
information they code. A user unit must then interpret
the information represented by the patterns before it can
determine whether it is a position-coding pattern or an
address-coding pattern. The address-coding pattern cannot
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be interpreted as positions since the positions to which
they are then decoded will not be associated with each
other, which is the case of the position-coding pattern.
The address area advantageously codes also a public
key, the receiver specified by the address being capable
of decoding a message which has been coded by means of
the public key. This facilitates the encryption of the
message that has been written manually in the writing
area.
By using the above-mentioned sequences for coding
the address-coding pattern, it will be possible to store
long encryption keys in the address.
The address-coding pattern is alternatively divided
into a plurality of code fields each of which corresponds
to a character. An arbitrary address portion on the
address-coding pattern means that the address portion is
associated with one code field only. Each code field can,
for example, define a specific code area on a virtual
surface. The partial code areas on the virtual surface
are in turn associated with different characters.
According to a less preferred embodiment, the
address-coding pattern is a bar code. However, it will
not be possible to provide a bar code which car. be
recorded on several occasions. Besides, a bar code will
be less compact.
In the case where the address-coding pattern is
divided into code fields, the code fields are preferably
separated by separating fields. By the code fields being
separated by separating fields, the identification of the
different code fields will be facilitated.
A user unit for electronic transmission of handwrit-
ten information according to the invention comprises a
reading head and a memory and is adapted to optically
record images from a surface by means of the reading
head. The user unit is characterised in that it further
is adapted to convert the recorded image to at least one
position and store the position in the memory in response
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to the fact that the recorded image contains a position-
coding pattern which codes at least one position, convert
the recorded image to at least one character and store
the character in the memory in response to the fact that
the recorded image contains an address-coding pattern
which codes at least one character, and transmit at least
part of positions stored in the memory to an address cor-
responding to characters stored in the memory. Handwrit-
ten information can thus easily be transmitted to a pre-
determined address by means of a user unit according to
the invention.
A product according to the invention, together with
a user unit according to the invention, can be used, for
example, to order articles. A user then inputs which
articles he wants to order together with his address.
When the receiver defined by the address receives the
message, the receiver sends the ordered articles to the
inputted address.
There are a number of alternatives to the way the
recording of images is to be initiated. According to an
embodiment of the invention the user unit comprises a pen
point. The user unit is then adapted to record images as
the pen point is being pressed against a surface.
The user unit is advantageously adapted to convert
a first part of characters stored in the memory to an
address and a second part of characters stored in the
memory to writing-area information defining a writing
area, and to send only positions contained in the writing
area to the address. This prevents information that has
been recorded on other surfaces than the writing area
from being sent to the address.
The user unit is advantageously adapted to attach
recorded images of the address-coding pattern to a set
of sequence portions, to convert the set of the sequence
portions to a set of sequence values, and to convert the
sequence values to characters by means of information
stored in the memory.
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The user unit is advantageously adapted to attach
an identification number when sending information to the
address, said identification number being unique for each
user unit. This permits identification of the user unit.
A memory medium according to the invention can be
read by a computer. A computer program is stored on the
memory medium and is adapted to be used for inputting
handwritten information and electronic transmission of
the information. The computer program is characterised
in that it contains instructions for making the computer
read an input signal corresponding to a recorded image,
convert the recorded image to at least one position and
store the position in response to the fact that the
recorded image corresponds to a position-coding pattern,
convert the recorded image to at least one character and
store the character in response to the fact that the
recorded image corresponds to an address-coding pattern,
and transmit stored positions to an address corresponding
to characters stored in the memory.
The above features can, of course, be combined in
the same embodiment.
In order to further elucidate the invention,
detailed embodiments of the invention will be described
below without, however, the invention being considered
restricted thereto. The Figures are intended to illu-
strate the invention as distinctly as possible. The
Figures are not according to scale and some dimensions
are greatly exaggerated to show more clearly specific
features of the invention.
Brief Description of the Drawings
Fig. 1 illustrates a product according to an embodi-
ment of the present invention.
Fig. 2 shows a user unit and a communication device
according to an embodiment of the present invention.
Fig. 3 shows symbols according to a preferred embo-
diment of the present invention.
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Fig. 4 shows a sequence which is used to code tie
coding patterns according to an embodiment of the present
invention.
Fig. 5 illustrates how part of the address-coding
pattern is converted to an address.
Fig. 6 shows how part of the position-coding pattern
is converted to positions.
Fig. 7 shows the fundamental composition of an
address area.
Fig. 8 shows schematically how an ordering operation
according to the invention is done.
Fig. 9 shows the conversion of part of the address-
coding field at different heights in the address area
according to the present invention.
Fig. 10 shows schematically an address area accord-
ing to an alternative embodiment of the present inven-
tion.
Detailed Description of the Invention
Fig. 1 shows a product according to a preferred
embodiment of the present invention. The product is a
sheet of paper 1, which comprises a writing area 2 and
an address area 3. According to a preferred embodiment
of the present invention, the sheet of paper 1 is a page
in a newspaper. The writing area comprises a position-
coding pattern which consists of a plurality of position
symbols 4 arranged in a matrix. The symbols in Fig. 1 are
greatly exaggerated in respect of size. A first arbitrary
position area 5 of the writing area unambiguously defines
a position on the sheet. The address area comprises an
address-coding pattern with a plurality of address sym-
bols 6. The address symbols 6 are greater than the posi-
tion symbols, which makes it possible to easily distin-
guish the different patterns. An arbitrary address por-
tion 20 of the address area defines a character. The
position-coding pattern and the address-coding pattern
thus have the property that if an arbitrary part of the
pattern of a certain minimum size is recorded, a position
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and a character, respectively, is unambiguously defined.
The coding patterns will be described in more detail
below.
The position-coding pattern can be of the type as
5 disclosed in the above-mentioned US 5,852,434, where each
position is coded by a specific symbol.
However, the position-coding pattern is advanta-
geously of the type disclosed in Applicant's Applica-
tions SE 9901954-9 and SE 9903541-2, where each posi-
10 tion is coded by a plurality of symbols and each symbol
contributes to the coding of several positions.
The position-coding pattern is made up of a small
number of types of symbols. An example is disclosed in
SE 9901954-9 where a larger dot represents a "one" and
a smaller dot represents a "zero". Another example is
disclosed in SE 9901954-9, where four different displace-
ments of a dot in relation to a raster point code four
different values.
Fig. 2 illustrates a user unit 14 which is adapted
to record images from a surface. The user unit comprises
a light-emitting diode 7 for illumination of the surface
to be recorded, an image sensor 8 in the form of a CCD
for recording of images, an image-processing means 9 and
a memory 10. The user unit 14 further has a battery 12
for supplying power to the reading head and buttons 13 by
means of which the reading head is turned on. Fig. 2 also
shows a communication device 15 in the form of a computer
which is disconnected from the user unit 14 and which is
connected to a network via cables 18, 19. The network is
in this case the public telephone network but could also
be an internal network. The user unit 14 is provided with
a transmitter 16 for transmitting of recorded informa-
tion. The user unit transmits information to the communi-
cation device which transmits the information by the pub-
lic telephone network. In the latter case, the user unit
is a mobile unit in a mobile communication system and
transmits information to the mobile communication system
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by means of the transmitter 16. The user unit also com-
prises a pen point 21 by means of which a user can enter
information. The pen point is pressure-sensitive and con-
nected to the image-processing means. When the pen point
21 is pressed against a base, the recording of an image
is initiated. Thus, recording of images is initiated when
a user enters information in the writing area. The commu-
nication device 15 is provided with a receiver 17 for
receiving information from the user unit. The transmitter
and the receiver communicate, for example, by using IR or
radio waves.
According to an alternative embodiment, the trans-
mitter 16 constitutes a communication device which com-
municates with the world around via a mobile telephone
system. The user unit then constitutes a mobile unit in
a mobile telephone system.
Figs 3a-d show an embodiment of a symbol which can
be used in the matrix in Fig. 1 according to the inven-
tion. The symbol comprises a virtual raster point 28
which is represented by the intersection between the
raster lines, and a marking 29 which has the form of a
point. The value of the symbol depends on where the mark-
ing is located. In the example in Fig. 3 there are four
possible locations, one on each of the raster lines
extending from the raster points. The displacement from
the raster point is the same for all values. The symbol
has in Fig. 3a the value 0, in Fig. 3b the value 1, in
Fig. 3c the value 2 and in Fig. 3d the value 3. In other
words, there are four different kinds of symbols. Each
symbol can thus represent one of four values "0-3".
Fig. 4 illustrates a sequence 32 that is used to
code the address in the address-coding pattern and posi-
tions in the position-coding pattern. The sequence 32
comprises 512 values 33 which each are either "0", "1",
"2" or "3". An arbitrary subsequence 34, 35 with five
values unambiguously defines a sequence value which
corresponds to the position of the subsequence in the
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sequence 32. Each subsequence appears only once in the
subsequence. Thus, the first subsequence 34 corresponds
to the value "0" and the second subsequence 35 to the
value "1". Sequences of this kind are described in
"Pseudo-Random Sequences and Arrays" by F. Jessi
MacWilliams and Neil J.A. Sloane in "Proceedings of tile
IEEE Vol. 64 No. 12 December 1976".
Fig. 5 shows part of the address-coding pattern 2 in
Fig. 1. The address-coding pattern consists of a matrix
20 with symbols 6. The columns 36 in the matrix consist
of sequence portions of the sequences which have been
described above in connection with Fig. 4, in which the
values have been converted to symbols.
The recording of an address from an address-coding
pattern 2, 5 will now be described with reference to
Figs 1, 2 and 5. When the reading pen is passed across
the address-coding pattern 3, an image of a first address
portion 20 is recorded, with five times five symbols 6
arranged in columns 36 which each constitute a subse-
quence. Each of the symbols 6 is one of the four diffe-
rent symbols that are shown in Fig. 4. The image-process-
ing means converts the subsequences 36 in the matrix to
subsequences 39 with values 40. Each subsequence with
values corresponds to a sequence value 27 corresponding
to the position in a sequence with 512 values each of
which is either "0", "1", "2" or "3". If an image is
recorded, which is displaced one row in the matrix,
sequence values corresponding to the next position ir_
the sequence are obtained. The user unit converts the
subsequences 39 to sequence values 27. Subsequently the
user unit calculates data values 26 as the difference
modulo 1024 between the sequence values 27 for adjoining
columns. By the sequence values 27 increasing to the same
extent for each column if the recorded image is disp-;aced
in the direction of the column, the data values which
equal the difference between the sequence values are
independent of at which height the image is recorded.
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Then the data values are converted to binary values and
the eight least sigr:'_ficant bits in each character value
are converted to characters 11 which are stored in the
memory 10 while the Two most significant bits from four
adjoining character values are used as position for the
columns. Thus a tota-~ of 256 different characters can
thus be coded. The c:~:aracters 11 constitute part of the
address.
Fig. 6 shows part of the position-coding pattern 2
in Fig. 1. The first matrix 61 in Fig. 6 is the smallest
matrix which unambia~aously defines a position. The posi-
tion-coding pattern in the writing area is made up of
symbols 62 like those shown in Fig. 3. The difference
between the symbols ~2 in the writing area 2 and the sym-
bols 6 in the address area 3 is that the symbols in the
address area are larger than the symbols in the writing
area. In the position-coding pattern the four different
values are used to code a binary bit in each of two
orthogonal directiora. Thus, the four different values
"0, 1, 2, 3" code the four different bit combinations
(0, 0), (0, 1), (1, 0), (1, 1) where the first digit in
each bit combination relates to a first direction and
the second digit relates to a second direction which
is orthogonal to the first direction. When a user unit
records the first matrix 61 in Fig. 6, it is converted
to a second matrix 63 with values 64, which defines the
x coordinate, and to a third matrix 65 with values 66,
which defines the y coordinate, by means of the above
relationship between values and bit combinations. The
second and the third matrix contain subsequences 67 with
values which are each either "0" or "1". In the third
matrix the subsequences constitute rows in the matrix
while the subsequences constitute columns in the second
matrix. Each of the subsequences 67 is part of a writing
area sequence similar to the sequence shown in Fig. 4.
Thus each subsequence has a unique sequence value. Each
of the matrices 63, 55 with values is converted to a set
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of five sequence values Sxl-Sxs and Syl-SyS, respectively,
which define the position of the different subsequences
in the sequence. Then the difference between adjoining
sequence values is calculated, which causes two sets of
four difference values Dxl-Dx4 and Dyl-Dy4, respectively,
Dxn=Sxn+i-Sxn modulo R, where R is the number of unique
subsequences in the writing area sequence and Dyn=Syn+i-SYn
modulo R. Subsequently the difference values are used to
generate an x coordinate and a y coordinate.
Fig. 7 is a schematic view of the contents in the
address area. The address area contains a communication
part 22 which specifies which communication medium is to
be used, a character part 23 which specifies the address,
a code part 24 which specifies a public code which can be
used to encrypt the message and a position part 25 which
defines a partial code area in the writing area. The
receiver defined by the address can decrypt the message
which has been encrypted with the public key.
According to the preferred embodiment the product
constitutes a page in a newspaper. For instance the writ-
ing area and the address area are part of an advertise-
ment offering the readers to buy a product. The writing
area 2 is intended for entering the address to which the
product is to be sent. When a user begins to enter infor-
mation in the writing area 2, the CCD records images
which are transmitted to the image-processing means 9.
The user unit 14 is arranged in such manner that the
recorded images at least contain such a number of symbols
that the position on the sheet of paper can be determin-
ed. The image-processing means 9 recognises that the pat-
tern in the image corresponds to a position-coding pat-
tern and converts the pattern in a submatrix to a posi-
tion that is stored in a position sequence in the memory
10. As long as the pen point 21 records that the pen
point 21 is pressed down, new images are recorded. If the
user interrupts his writing and then once more begins to
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write in another position than the one where he stopped,
the position sequence will define a discontinuous curve.
When the user scans the reading head across the
address area, images are recorded, which are sent to the
5 image-processing means 9 which recognises that the pat-
tern in the image corresponds to the address-coding pat-
tern in the address area. The image-processing means 9
converts the symbols in the recorded image to characters,
which are stored in a string of characters in the memory
10 10. The conversion from symbols 4, 6, 62 to characters
has been described above. When the pen point 21 does no
longer record a pressure, the recording of images is ter-
minated. The position sequences stored in the memory,
which are associated with the area that is specified by
15 the position part 25, are encrypted by means of the pub-
lic key which is defined by the code part 24 and sent to
the address which is defined by the character part 23.
According to the preferred embodiment of the present
invention, also an identification number is transmitted
with the encrypted position sequence. The identification
number is unique for each user unit. A receiver can iden-
tify the customer by means of the identification number.
According to the preferred embodiment, the user unit
distinguishes the different parts in the address area by
their being separated by separating characters. An alter-
native possibility is that the number of characters in
each part of the address area is predetermined. The user
unit can thus easily determine when part of the address
area is finished.
Fig. 8 shows schematically how a user unit and a
product according to the invention can be used. A user 41
inputs a message in a writing area on a product by means
of a user unit 42 as described above. The user unit 42
sends encrypted position sequences together with an iden-
tification number to a receiver 44, who is a florist,
via a communication link 43. The position sequence cor-
responds to a handwritten address with a greeting. The
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receiver 44 sends flowers and the greeting to the hand-
written address. The receiver then consults a database
46 via a communication link 45. In this case the database
46 is not located with the receiver 45. The receiver 44
obtains information from the database to allow him to
send an invoice to the user 41, which is indicated by the
dashed line 47, or the invoice is sent from the database
to the user, which is indicated by the dashed line 48,
whereupon the receiver obtains payment from the database.
An alternative field of application is to enter the
answer to a question in a competition in the writing area
2 in the product 1. When the user 41 then scans the user
unit across the address area, the answer entered is
transmitted to the receiver together with the user unit's
14 identity. Then the receiver can in the same way as
above consult the database to find out who is the owner
of the user unit and send prize money, if any, to the
owner.
Fig. 9 illustrates how the information from images
recorded at different heights in the address area is pro-
cessed. The first image 50 contains five times five sym-
bols. The symbols 51 are converted to the values as
described in connection with Fig. 5. The values in the
columns are then converted to sequence values correspond-
ing to the position of the subsequence in the sequence.
The five subsequences with symbols corresponding to the
columns in the first image 50 are thus converted to a
first set of five sequence values 52. The first set of
five sequence values 52 is then converted to a first set
of difference values 53 which in turn is converted to
characters in the same way as described in connection
with Fig. 5. When a third image 56 containing five times
five symbols is recorded, the five subsequences consist-
ing of five symbols are converted to a second set of five
sequence values 54. The second set of five sequence
values 54 is then converted to a second set of difference
values 55 which in turn is converted to characters in the
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same way as described in connection with Fig. .~. Each of
the sequence values 54 in the second set is four units
greater than the sequence values 52 in the first set
since they are fetched further down in the seauences of
which the sequence parts constitute a part. However, each
of the difference values 53 in the first set of diffe-
rence values is the same as the corresponding difference
value in the second set of difference values. Thus, the
difference values are independent of at what height in
the address area 57 the images are recorded.
Fig. 10 shows an address area according to an alter-
native embodiment of the present invention. The address
area 31 is divided into a number of subareas 37, which
each comprise a position-coding pattern. Each subarea
thus defines a partial code area on a virtual surface.
The subareas are separated by separating fields 38. The
user unit has in its memory information about which char-
acter is associated with a certain partial code area on
the virtual surface. When the user unit records a sepa-
rating field, it can determine that it has reached the
next character in the address area. The drawback of this
embodiment is that the address will be less compact.
The above embodiments are to be considered examples
only.
A person skilled in the art realises that the above
embodiments can be varied in a number of ways without
departing from the inventive idea. For instance, the com-
munication device and the reading device can be an inte-
grated unit.
It goes without saying that each symbol can define
a number with a base other than four.
It is within the scope of the invention that the
address area merely comprises the code field, the user
unit, for example, being adapted to always use the same
communication medium.
