Device for electroconductive connection and reading

A device for electrical connection of marks produced by means of an electroconductive writing substance to a readout device, by applying said marks in electroconductive relationship with pairs of mutually isolated conductive paths on at least one isolating substrate. Said substrate with its pairs of paths is removably connectable to the readout device by means of separate connection elements for each path. A mark bridges the conductive paths in one pair and closes an electric circuit on at least one substrate, whereby readout can take place without mechanical motion, and all electric circuits on such a marked substrate exist at the same time and the marks are readable electrically as well as visually.

The present invention relates to a device for electroconductive connection 
between a readout device and marks for reading the marks, whch are 
produced by means of an electrically conductive writing substance, which 
are also optically detectable and which represent data. 
Known devices making possible such a connection for reading are usually 
associated with some kind of mechanical motion, the presence of a mark for 
instance being sensed by a movable brush or the like. Examples of such 
devices are found in the U.S. Pat. Nos. 2,171,556 and 3,461,276 and in the 
German Pat. No. 923,095. Thus, this known technique does not permit 
readout without mechanical motion, and it is not practically possible, to 
add new marks during the readout process, which is often desired with real 
time processing. Moreover it is necessary always to perform readout in the 
same sequence due to the mechanical construction used. 
Other devices known, for instance according to the U.S. Pat. No. 3,678,251, 
permit fairly careful readout without mechanical motion, but present 
instead a strong restriction of the number of marks that can appear 
simultaneously and be read, as the device is based on the principle with 
analogous readout. 
The invention is based on the principle of creating a connection making 
possible readout of marks on one or more substrates without mechanical 
motion. 
The disadvantages associated with known technique are eliminated with a 
device according to the invention by measures reported in the 
characterizing portion of the appended claim 1. 
The principle of the invention is that the readout device is connectable to 
electric circuits, each circuit comprising: two or more conductive paths 
or sheets, which are isolated from each other and are positioned on and/or 
in one or more isolating substrates, and two connection elements, which 
each makes contact with its conductive path, preferably under pressure, 
and via which the electric circuit is electroconductively connectable with 
the readout device, and one or more marks, which close the electric 
circuit and which are alternatively applied (a) on conductive paths on the 
same isolating substrate and possibly on this substrate (FIG. 1), or (b) 
on an isolating substrate without paths, which substrate is combined with 
another isolating substrate with conductive paths, which are in conductive 
contact by the mark (FIG. 2), or (c) on a first conductive path on an 
isolating substrate and partly on this substrate, in addition to which a 
second conductive path on another isolating substrate is in conductive 
contact with the first conductive path through the mark (FIG. 6), all 
marks to be read from the same or different substrates being included in 
their simultaneously present electric circuits and readout therefore 
taking place without mechanical motion. By mechanical motion for instance 
motion of substrates relative to each other or motion of the readout 
device relative to the substrates or vice versa is intended. 
By the invention it is possible to write down marks at the same time as 
readout is going on. By the marks a graphical storage of data is achieved, 
which are legible optically as well as electroconductively, and in this 
way an optical as well as an electrical memory function is obtained. 
The electrically conductive writing substance should have such properties 
that it can be applied over conductive paths and/or substrates by means of 
writing implements, such as a pen or a pencil, or by means of some 
printing method, or in other manner. After application the material should 
have a resistivity suitable for electrical contact. 
The expression "electrically conductive paths" does not mean any 
restriction with regard to the shape of the paths or the method of 
applying them on or in the substrate. The paths can thus e.g. occur as 
layers, threads, fibres or points, but may also have the shape of bands, 
strips or sheets, all depending on the intended purpose. 
Within the scope of the invention the conductive paths may also have 
arbitrarily reciprocal positions. However, they should be arranged so that 
electric circuits can be formed by their having a short distance between 
each other at least at the positions, where the writing substance is to be 
applied. This condition can be satisfied by the paths being applied on the 
same or different isolating substrates. The paths can for instance also be 
placed irregularly or be positioned in a latticed pattern or in the form 
of a net. However, the condition is that electric circuits are formed by 
means of marks and that the electric circuits are arranged so that 
electroconductive readout is made possible.

According to FIGS. 1a, 1b conductive paths 12 are positioned on an 
electrically isolating substrate 11. The conductive paths are electrically 
isolated from each other and are separated from each other on the 
substrate by means of an interspace 13. An electrically conductive writing 
substance 14 is used, which has the previously mentioned properties. It is 
applied so that it covers two or more conductive paths. The writing 
substance 14 applied is shown in the figures by means of a plan view in 
the form of a cross. According to FIGS. 1a, 1b the writing substance is 
applied over two conductive paths 12 and over the interspace 13 between 
these on the substrate 11. Moreover, the paths are connected with a 
readout device 16 for electroconductive readout via connection elements 
15, which make contact, for instance under spring pressure, with portions 
of the conductive paths intended therefor. Thus, each electric circuit and 
each mark, respectively, has a sense of its own in respect of information, 
is separated and, possibly simultaneously with other marks on the 
substrate, is optically as well as electroconductively legible. In the 
figure an explaining text of the substrate in FIG. 1b is given as a 
non-binding illustrative example, which text refers to airport booking, 
the purpose of the marks appearing optically. 
The sense of the data elements applied by marks can be of many different 
types. Thus, it can also indicate hotel booking or the like, and in all 
cases the information will be optically as well as electrically available. 
As data will be electrically legible according to the invention, the 
substrates, on which a conductive writing substance has been applied, can 
be used in a possible continued data processing in a conventional manner. 
According to FIGS. 2a-2c a writing substance 14 is applied on another 
substrate 11b than the substrate 11a, on which the conductive paths 12 are 
applied. In this case the electrical connection of the conductive paths on 
the substrate 11a takes place by the two substrates 11a and 11b being 
compressed or combined with the paths 12 and the writing substance 14 
turned towards each other. This state is shown in FIG. 2c, where the 
substrates are shown compressed with a force F. 
The text on the substrate in FIG. 2b indicates an example of reception 
control in a hotel with points of time of occurrences, such as calling, 
departure and arrival. In addition to readout of information the readout 
device 16 can connect via a time device acoustic or optical signalling for 
reminding of the information content. Also at a substrate 11a applied to 
the substrate 11b the marks 14 can in this example be optically legible, 
if the substrate 11a is quite or partly made of a transparent material. 
At the embodiment of the invention shown in FIGS. 3a-3c the electrical 
connection of the conductive paths is intended to be effected in such a 
way that marks of arbitrary appearance can also be written, after which 
readout can take place optically as well as electrically. The electrical 
connection is brought about by applying the writing substance 431 on 
conductive paths in the form of a system of coordinates in two planes and 
form contact points between the paths at the crossings between paths in 
the different planes. Conductive paths 23a, 23b which are reciprocally 
isolated, are arranged on a substrate 21 in two planes, the paths in the 
two planes being isolated from each other by an isolating layer 22. The 
system of coordinates in the example has perpendicular paths. 
If a mark of arbitrary appearance, e.g. a C, is applied by means of a 
writing implement over the conductive paths, the conductive writing 
substance 431 will close contacts between paths in different planes, so 
that the mark will be electroconductively legible in coordinate 
representation at the same time as it is optically legible. The writing 
substance 431 should have a resistivity preventing erroneous reading due 
to longitudinal current conduction along the writing substance. It also 
contributes to preventing erroneous reading, if the uppermost conductive 
paths 23b are provided with an isolating layer on their upper surface. To 
the right in FIG. 3b a groove between two paths 23b is shown, which is to 
have an isolated upper surface, but where parts marked more strongly at 
the edges of the paths towards the groove and at the bottom of the groove 
indicate places where the writing substance makes electrical contact. In 
FIG. 3c also such a groove has been marked furthest to the right. Each 
path 23a and 23b is electrically connectable with a readout device via a 
connection element of its own. 
FIGS. 4a and 4b show a number of substrates 75a, 75b, 75c provided with 
marks, for instance paper sheets, which are to be placed on each other. On 
these paper sheets pre-prints may be present as in FIGS. 1 and 2 for a 
desired application object. Information on these paper sheets is 
represented by the presence of marks 50 of writing substance between a 
path 20a, 20b, 20c common to each sheet, and one or more conductive paths 
41, 42, 43 (each a - d) reciprocally isolated, and also, as will be 
explained below more in detail, a sheet selecting, conductive path 31, 32, 
33 (each a - c). To make possible connection of conductive paths 31, 32, 
33 and 41, 42, 43 placed over each other on different paper sheets, each 
such path is in some way connected with a piece of conductive path 34, 35, 
36 (in FIGS. 4b, 34a, 35a, 36a) located on the rear side of the sheet, at 
least at one of its edges, and in this way geometrically identical 
conductive paths on different paper sheets will be connected with each 
other, when the sheets lie upon each other and are exposed to contact 
pressure F between a connection element 30 and conductive paths 33 and 43 
on the uppermost paper sheet. 
By applying a writing substance 50 between the conductive paths 20 (a - c) 
common to each paper sheet, and the conductive paths 31, 32, 33 (a - c) 
adapted on the sheets, and serving as sheet selectors, for instance 
between the paths 20a and 33a on the sheet 75a or between the paths 20b 
and 32b on the sheet 75b, a paper sheet, from which information in the 
form of marks is to be read, can be selected electronically by means of an 
electronical readout device 60, which is common to all the paper sheets. 
Via connection elements 30 (a - c) and 40 (a - d), which are each common 
to all the sheets, the electronic readout device 6 is connected with the 
sheet selecting paths 31, 32, 33 and with the conductive paths 41, 42, 43 
on each sheet supplying the information. Reading takes place by 
electronical switches in the readout device 60 connecting readout circuits 
in this with the connection elements corresponding to the desired paper 
sheet. If for instance the connection element 30a is connected with the 
readout circuits, marks on the sheet 75a will be read. In FIG. 4a two step 
switches are indicated in the readout device 60, of which the uppermost 
one connects in turn the sheets 75a - 75c, while the lower step switch is 
intended to read for each sheet the electric circuits with respect to 
marks existing there. Thus, reading of all the marks 50 can take place 
without mechanical motion of the electronic readout device relative to the 
sheets 75 and without mechanical motion of the sheets relative to each 
other. Thus, it is not necessary that marks to be read electrically are 
visually available in reading. 
FIGS. 5a-5c show a modification of the invention. Electroconductive paths 
82a, 82b are each positioned on its substrate 81a, 81b. The placement of 
the paths is such that they will be close to each other with an interspace 
for electrical isolation when the substrates are put against each other. 
An electrically conductive writing substance 84 can be applied on and 
outside the conductive path on one of the substrates, for instance 
according to the figure on the path 82b and the substrate 81b. When the 
substrates will be put together as indicated above, the writing substance 
applied will make contact between the conductive paths on the two 
substrates, as the part of the writing substance on the substrate 81b will 
get in contact with the conductive path on the other substrate 81a. The 
conductive paths can preferably continue around the edge and some way into 
the rear side of the substrates. This is shown in FIG. 5c as well as how 
one can achieve electrical connection between the paths and a readout 
device 86 for electroconductive reading by means of contact springs 85 as 
connection elements. The parts of the paths on the rear sides of the 
substrates are designated by 83a and 83b. 
The conductive paths may for instance consist of metal applied by 
evaporation to a paper sheet in a desired pattern, and the marks can then 
be made by means of a pencil. 
In FIG. 6 additional examples of paths positioned in different planes are 
shown. The paths 103 and 104 are completely embedded in the substrate 102, 
are isolated from each other and form a system of coordinates. The paths 
appear by branching for instance only on one surface of the substrate 102 
in the form of points 103a and 104a, their position in the coordinate 
field being defined. The paths also appear on the surface for contact with 
the connection elements 105. An electroconductive substance applied in the 
form of a mark 106 closes electrically two paths belonging to the x- and 
y-axis, respectively, near to a point of crossing in the system of 
coordinates. The path points are placed near to each other in pair to make 
clear the position of the mark. 
A variant of this embodiment is for instance if the y-paths 104 are placed 
completely on the surface of the substrate in the form of strips beside 
the points 103a. Several variables can be established in similar manner, 
which have the common properties that paths or their branchings, for 
instance 103 and 103a, belonging to the x- and y-axis, appear together on 
one or both of the substrate surfaces in practically any shape, to be 
connected by an electroconductive substance, while the other parts of the 
paths that are not intended for contacting, can be positioned in or on the 
substrate, on the other side of the substrate, in or on isolating layers 
which are in some way or other combined with the substrate etc. As 
distinguished from FIG. 3b the paths are according to FIG. 6a connected by 
a writing substance in one and the same plane. 
FIG. 7 shows a device for recognizing characters. It is a combination 
between a device with common paths and paths positioned in different 
planes. A common path 73 of mainly rectangular shape has a number of 
incisions and a central square hole. Seven character identifying paths 
74(1-7) appear in the incisions and the square hole of the common path on 
the same surface on the substrate so near each other that a mark with an 
electroconductive substance can connect one or several of these 
identifying paths with the common path. In FIG. 7a only that part of the 
paths to be connected by the body line (contour line) of the character is 
shown, and must consequently appear on one surface of the substrate. In 
FIG. 7c the remaining part of the paths 74(1-7) is shown with broken 
lines, which means that they are positioned in the substrate or on the 
other side of the substrate. 
All the paths are electrically isolated from each other and positioned on 
and/or in the substrate, for instance as in FIGS. 3 and 6, or in another 
manner. The paths are connectable to a readout device via connection 
elements. A character identifying path 74-1 and the closest part of the 
common path (in FIG. 7a parts marked more strongly) constitute one pair of 
paths, which is electrically connected by the writing substance and forms 
an electric circuit in a way as described above. Such a circuit is an 
electrical memory element. In the example here described seven identifying 
paths and memory elements, respectively, are included. The identifying 
paths are regularly spread in a two-dimensional field of coordinates and 
form together with the common path a memory group suitable for recognizing 
for instance decade digits, provided they are written in a certain size 
and the body line follows a certain pattern. In FIG. 7c the digit 6 is 
applied by means of an electroconductive writing substance on the 
right-hand memory field and connects the identifying paths 74-1, 2, 4, 5, 
6 and 7 with the common path 73-2, forming six electric circuits. Through 
these six electric circuits the readout device can identify the digit 6. 
In FIG. 7b the identifying paths do not have identical shape and are not 
symmetrically placed. Similar measures can adapt the memory field to 
different hand-writings. In the same figure a pattern is shown indicating 
how the digits (to the right of the field) are to be written. The digit 4 
can be written in two different ways, 7 in several ways etc. All the 
characters should be written with the same size and position on the field. 
An increased number of identifying paths eliminates this disadvantage. 
The body line of the character is thought to be divided into several 
sections, which extend between two adjacent pairs of paths. In FIG. 7c, 
where the digit 6 is applied, the body line is thought to be divided into 
six sections. The number of the sections and their position relative to 
each other in the memory group are specific to the character. The digit 9 
has also six sections, but they have another position relative to each 
other. Several memory groups can be placed on the same substrate (FIG. 
7c). The paths 74(1-7) are connected in parallel, but the common paths are 
separated and used as means for character searching on the substrate. By 
an adapted design of the readout device information written down can be 
read in the desired sequence or simultaneously from each of the memory 
elements or memory group. 
The number of character identifying paths appearing in a memory group can 
vary with the configuration of the characters applied. The form of the 
common path used on the surface of the substrate can be designed as a 
circle, spiral, system of coordinates, net, a star with several angles, 
several points etc. to obtain a satisfactory resolution. As examples of 
applications of the device for recognizing characters automatic telephone 
dialling, automatic data processing etc. can be mentioned. 
According to the invention the substrates, for instance paper sheets, are 
i.a. intended for treatment, i.e. to be provided with notes and be marked, 
while they are connected to the readout device. This presupposes a long 
line with several wires between sheet and readout device, if these are not 
arranged together, and is unpractical if both are positioned on a 
writing-table. This disadvantage is eliminated by placing the sheets on a 
pad that is extended for having room for the readout device or the like. 
The appearance of the extended pad can be compared with a handy note-book 
that can easily be moved. In certain cases it is necessary to connect the 
extended pad to other devices, for instance for data processing, and then 
it is important to use a minimum number of lines, which can be realized if 
the built-in components convert the marks into a pulse train. 
In FIG. 8 an extended pad 128 is shown, on which the sheet 120 is placed. 
Two holes 126 in the sheet and two guide pins 127 on the pad fix the 
position of the sheet and of the paths, respectively, on the pad. A 
foldable cover 129 on the left side of the sheet, presses by means of a 
spring the connection elements 125 against the sheet and the paths, 
respectively, to produce electrical contact and to attach the sheet 
simultaneously to the pad. The position of the cover relative to the sheet 
can be fixed by means of the same guide pins. A flexible and isolating 
underlayer 130 is underneath provided with printed conductors 131 and at 
the left hand side with printed circuits. The conductors 131 connect the 
active and passive components 132, forming the readout device or the like, 
with the connection elements 125. The part of the flexible conductors 131 
carrying the connection elements 125 is bound to the cover 129 and follows 
its movements, while the other part with the components 132 is bound to a 
rigid board 133. The connection elements 125 can consist of the wire 
conductors 131 themselves by a special design and treatment of the 
conductors. 
In another variant the components can be placed on the foldable cover and 
be directly connected to the connection elements. A third design makes it 
possible for the cover 129 to be stationary, while part of the pad 128 is 
foldable. An arrangement with one or several rolls placing the sheet in 
the right position and pressing the sheet against the connection elements, 
is a fourth variant. 
Several sheets intended for separate readout can be bound to a note-block. 
The electrical readout of each sheet can take place by opening the block 
and securing the sheet in question to the connection elements.