Note: Descriptions are shown in the official language in which they were submitted.
CA 02694383 2010-01-25
Security element having a plurality of optically variable structures
100011 The invention relates to a security element having an optically
variable
structure which has an embossed structure. The embossed structure is combined
with a coating contrasting to the surface of the security element in such a
way that
at least partial areas of the coating are visible upon viewing under a first
viewing
angle range, but are concealed upon viewing under a second viewing angle
range.
Upon tilting the security element around an axis and thus alternating viewing
from
the first and the second viewing angle range thus a tilt effect is produced
which
from the two different angles of view or under different angles of light
incidence
shows different colors or brightnesses.
[0002] Concerning this, for example, from WO 97/17211 a data carrier with an
optically variable element is known which consists of an embossed structure
and a
coating in the form of a print image or line grid. The embossed structure or
the
coating here are supplemented by a partial change of their structure such that
either
an intensification of the already known optically variable effect takes place
or at
least one further visually recognizable effect occurs. The optically variable
element
is visually recognizable but due to its optically variable properties cannot
be
reproduced with the help of copying machines. Copying machines can render only
one single viewing direction, so that the optically variable effect, i.e. the
recognizability of different pieces of information under different viewing
directions
is lost. The known optically variable element therefore can serve as copy
protection.
[0003] From WO 02/20280 Al an optically variable structure is known which
consists of a coating and an embossed structure superimposed on said coating.
The
entire area provided with coating and embossed printing is divided into
partial
areas, in which uniquely for the entire surface either the coating or the
embossing
are varied. The other part (embossing or coating) in all partial areas is
formed in the
same fashion, i.e. in all partial areas it has the same regularities.
Different partial
embossed structures within the terms of WO 02/20280 Al are present, for
example,
when the partial embossed structures in the individual partial areas are
disposed to
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each other in a phase-shifted fashion, have different grid spacings or have
different
orientation, i.e. the partial embossed structures extend at an angle to each
other.
Additionally, the partial embossed structures in the individual partial areas
can also be
disposed mutually offset, the extending direction of the partial embossed
structures
remaining the same.
[0004] The invention is based on the object to improve the known security
elements
and in particular to further increase the protection from forgeries.
[0006] The invention here comprises a security element, a data carrier with
a security
element as well as an embossing tool for manufacturing a security element. The
data
carrier here is in particular a document of value, such as for example a bank
note, a paper
of value, a credit card, debit card or ID card, a passport, a deed and the
like, a label, a
packaging or another element for product protection.
[0007] According to the invention the optically variable structure has at
least one
second embossed structure which is disposed within the first embossed
structure and
additionally to the first tilt effect produces a second tilt effect.
Preferably, the second tilt
effect here either occurs within the first or second viewing angle range of
the first tilt
effect or upon the transition from the first to the second or from the second
to the first
viewing angle range of the first tilt effect.
[0008] In the first alternative, i.e. upon the occurrence of the second
tilt effect within
the first or second viewing angle range, the second embossed structure is
disposed at the
first embossed structure such that it is visible within the first or second
viewing angle
range and hardly or not visible within the in each case other viewing angle
range. A
viewer who views the security element according to the invention from that
viewing
angle range in which the second embossed structure is hardly or not visible
thus merely
sees the first embossed structure. From the other
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viewing angle range, however, the viewer additionally sees the second embossed
structure and upon tilting the security element around a second axis, which is
different from the first axis, the second tilt effect.
[0009] Especially preferred, the at least one second embossed structure here
consists of second embossed elements, which are set in each case on a flank of
the
first embossed elements at a given angle. The second embossed elements thus
protrude stub-like at a given angle out of a flank of the first embossed
elements and
cause on this side of the first embossed elements the second tilt effect. The
angle
with which the second embossed elements are set on a flank of the first
embossed
elements here corresponds to the angle between the first axis of the first
tilt effect
and the second axis of the second tilt effect.
[0010] Preferably, the first and second embossed structures are designed as
grid
structures and especially preferably as line grids with constant grid spacing,
with a
cross-sectional area which in particular is designed triangular, trapezoidal,
sinusoidal or semicircular, and preferably have the form of three-dimensional
line
structures/wave structures or similar structures, such as e.g. reliefs, in a
substrate.
The second embossed structures need not necessarily have the same cross-
sectional
area as the first embossed structures. Thus, for example, the first embossed
structures can have a triangular cross-sectional area, whereas the cross-
sectional
area of the second embossed elements is semicircular.
[0011] In the second alternative, i.e. upon the occurrence of the second tilt
effect
upon the transition from the first to the second or from the second to the
first
viewing angle range, the at least one second embossed structure is
incorporated in
the first embossed elements by a partial change of the geometry of the first
embossed elements. In this connection the first embossed elements preferably
have
a modulation of the height in longitudinal or transverse direction, of the
width or of
the inclination of the flanks, whereby the modulation of the width or the
inclination
of the flanks can be formed on one or the two sides of an embossed element. If
a
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viewer now tilts the security element around the first axis, in the areas in
which the
second embossed structure is located there will appear, additionally to the
first tilt
effect, the second tilt effect.
[0012] For example, the first embossed elements may consist of two flanks
disposed to each other in a wedge-like fashion which have different colors,
and the
second embossed structure is formed as a notch-like indentation at the point
of the
wedge in longitudinal direction of the point. The flanks of the indentation in
turn
have a color which contrasts to that of the adjoining flank of the first
embossed
elements. Upon tilting around the first axis a viewer thus first sees the
first flank of
the first embossed element and approximately at the end of the first viewing
angle
range additionally the first flank of the indentation which extends in
parallel or
nearly in parallel to the first flank of the first embossed element. Upon
further
tilting around the first axis the viewer also sees the second flanks of the
first
embossed element and of the indentation, until finally at first the first
flank of the
first embossed element and subsequently the second flank of the indentation
are
concealed by the second flank of the first embossed element. In the areas of
the
optically variable structure, however, in which no second embossed structure
is
located, upon tilting the security element around the first axis the viewer
sees
merely the two flanks of the first embossed structure, i.e. only the first
tilt effect
occurs.
[0013] The first and second embossed structures are preferably formed as blind
embossing. Blind embossings are produced in one printing operation using a
steel
gravure printing plate. Upon the printing operation the paper is pressed into
the
recesses of the blind embossing areas and is lastingly deformed in this way.
The
blind embossing areas of the printing plate, unlike print image areas, are not
filled
with ink, so that the substrate material of the security document in these
areas is
merely lastingly deformed, i.e. is embossed. Upon the viewing of blind
embossings
due to light- and shadow effects special three-dimensional optical impressions
are
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rendered. Moreover, blind embossings with appropriate dimensions can also be
easily detected tactilely.
[0014] When the embossed structures of the first or second embossed structures
have different heights, the blind embossing is also referred to as halftone
blind
embossing.
100151 In addition, the blind embossing can also be produced by means of
thermal processes. A substrate made of plastic material here is thermally
deformed
by action of heat, structures being representable finer than with a substrate
made of
paper. This method is used in particular with bank notes made of plastic
material or
cash cards, debit cards, credit cards, SIM cards, customer cards or the like.
[0016] In a further preferred embodiment the first and second embossed
structures are formed as ink-carrying embossing. Here the optically variable
effect
of the security element is preserved, although instead of the blind embossing
an ink-
carrying embossing is used. I.e., the optically variable structure at least in
partial
areas has a second coating which also contrasts to the data carrier surface
and is
disposed congruent to the raised areas of the embossed structure. The second
coating has the advantage that the embossed structure is stabilized without
additional printing operation. In addition, such a security element has the
advantage
that it can be integrated into an intaglio printing motif and thus into the
color design
and concrete design of a surrounding motif.
[0017] Upon the manufacturing of an ink-carrying embossing the gravure lines
of
the printing plate are filled with ink. The excess ink is removed with the
help of a
wiping cylinder or a doctor blade from the printing plate such that the
gravure lines
are filled to the brim with ink. Upon the printing operation the data carrier
to be
printed, in the normal case paper, is finally pressed with a high pressure
onto the
printing plate by means of a pressure cylinder which has an elastic surface.
The data
carrier here is pressed into the gravure lines of the printing plate which are
filled
with ink, and in this way comes in contact with the printing ink. Upon
detaching the
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data carrier, the data carrier draws the printing ink from the recesses of the
gravure
lines. The thus produced print image has printed lines which vary in their ink
layer
thickness depending on the depth of the gravure. The data carrier is pressed
into the
recesses of the printing plate so strong, that it not only absorbs the color
from the
recesses but at the same time is also embossed.
[0018] In an especially preferred embodiment, the embossed structures have
line-
shaped embossed elements, which preferably can extend straight, but also wavy
and/ or curved. A line-shaped embossed element is produced by a channel-like
recess in the embossing plate or the embossing cylinder. The recess has a
cross-
sectional form such that embossed elements with at least two opposite flanks
are
produced and each of these flanks is visible from different directions. For
example,
a triangular form of the recess produces two flanks which upon perpendicular
viewing are both visible. Upon oblique viewing only one flank is visible,
since the
respective other flank is concealed by the opposite visible flank. Upon
alternating
perpendicular and oblique viewing thus a tilt effect is produced.
[0019] Usually, the line-shaped grid structure of the coating and the line-
shaped
embossed elements are aligned in parallel to each other, so that on the one
flank of
the embossed structure there are disposed lines of a color and on the other
flank
lines of a different color. If a viewer looks obliquely onto the optically
variable
structure, depending on the viewing direction he will thus see one of the two
colors,
if he looks perpendicularly onto the optically variable structure, he will see
both
colors. By the interaction of coating and embossed structure thus a tilt
effect with
color change is produced.
[0020] In a further preferred embodiment the embossed structures have not line-
shaped embossed elements, as they are known in particular from WO 2006/ 018232
Al. Not line-shaped embossed elements have flanks of plane and/ or curved
surfaces, in particular the form of n-sided pyramids, tetrahedrons, frustums
of a
pyramid, segments of a cylinder, cones, conic sections, paraboloids,
polyhedrons,
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cuboids, prisms, sectors of a sphere, segments of a sphere, spherical
segments,
hemispheres, barrel-shaped bodies or tori. But the not line-shaped embossed
elements can also be formed as so-called divided torus, the torus being
divided in
parallel to that plane in which lies the large radius of the torus. Especially
preferred,
knob-like embossed elements in the form of segments of a sphere, or three- or
four-
sided pyramids are used. Not line-shaped embossed elements have the advantage
that in a simple way more than two pieces of information can be placed in the
optically variable element, which become visible under different viewing
angles,
since the not line-shaped embossed elements have a plurality of flanks on
which the
information or parts of the information can be disposed selectively and
separate
from each other.
[0021] The first and/or second embossed structures and/or the contrasting
coating
have at least one piece of information which is formed by the contour lines of
the
embossed or printed areas. This information has the form of a graphic image
and/ or
alphanumeric image and for example represents a number, a letter, a portrait,
an
animal, a plant, a landscape or a building.
[0022] The height and/ or lateral dimension of the embossed structures in
particular because of the roughness of bank note paper must amount to more
than
30 [im.
[0023] It is especially preferred, when the at least one second embossed
structure
is divided into individual partial areas, the second embossed structure acting
as
additional information. This second embossed structure, depending on the form,
among other things can conceal, accentuate, matt or shadow individual partial
areas.
Upon equal arrangement it has a clear information-supporting effect, upon
tapering
or disharmonious arrangement it can promote a tilt effect.
[0024] The coating is preferably formed as a flat single- or multi-colored
print.
The multi-colored print here consists especially preferably of a line pattern
in which
the lines directly adjoin each other or are spaced apart. In the first case an
area-
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covering line pattern preferably consisting of an alternating sequence of
three lines
in the colors cyan, magenta and yellow is applied to the data carrier. When
the lines
are spaced apart, the color of the data carrier's substrate preferably forms
one of the
lines of the line pattern. The two possibilities can also be combined. When,
for
example, there is printed onto a magenta-colored substrate an alternating
sequence
of two adjoining lines in the colors cyan and yellow, there being a gap
between each
line pair, the substrate forms the "lacking" third line of the sequence.
[0025] Usually, the lines of the individual colors are printed one after the
other
onto the substrate of the data carrier. In a first printing operation here at
first all
lines of a first color are printed, in a second printing operation all lines
of a second
color, in a third printing operation all lines of a third color etc. For each
color a
separate printing plate or a separate printing cylinder is used, to which the
respective ink is applied and subsequently printed onto the substrate of the
data
carrier.
100261 In principle, all colors can also be printed in one single printing
operation
onto the substrate of the data carrier. In doing so, the individual inks are
applied one
after the other or at the same time to one single printing plate or one single
printing
cylinder and are subsequently printed onto the substrate of the data carrier.
[0027] The print is effected with usual printing methods, i.e. in particular
by
planographic printing, such as by offset process, by relief printing, such as
e.g. by
letterpress printing or by flexographic process, by screen printing, by
gravure
printing, such as e.g. by halftone gravure or by intaglio printing, or by a
thermographic process, such as for example by thermal transfer process.
(0028] For the coating printing inks are preferably used which are completely
opaque. Especially preferred, printing inks with high translucent behavior are
also
used, i.e. printing inks consisting of translucent lacquers with a certain
portion of
coloring pigments. Likewise, transparent lacquers can be used to which are
added
machine-readable features, such as for example luminescent substances,
electrically
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conductive particles or IR- or x-ray-absorbing substances. The coating with
machine-readable features here contrast to the surface of the security
element, since
this surface does not have the machine-readable features. Of course, the
machine-
readable features can also be component of translucent or opaque printing
inks.
[0029] Preferably, the lines of the coating are formed as straight lines and
especially preferably are disposed in parallel to each other. Likewise, the
lines can
also be formed as concentric circles or confocal ellipses or have oval, wave-
shaped
or any other forms. Additionally, a combination of a plurality of these
embodiments
is also possible.
100301 The at least one second embossed structure can also be combined with a
second coating contrasting to the surface of the data carrier. Here on the
first
embossed structure the first coating is arranged and on the second embossed
structure the second coating. Upon viewing the second embossed structure the
viewer thus recognizes additional information which is disposed within the
coating
of the first embossed structure.
100311 The coating here is adjusted to the first and second embossed
structure.
Thus, it is possible by way of example for colors or patterns to be
selectively
separated, intensified, weakened or deformed in an oblique view and thus for
further additional information to be produced. In plan view or upon viewing
the
opposite flank this additional information remains hidden.
100321 Preferably, the coating and the embossed structures are set up with the
same spatial frequency, i.e. the grid spacing of the embossed structures and
of the
coating is the same. But it is also possible to use only similar spatial
frequencies so
as to produce beat effects or moiré effects, or to entirely do without the
interrelation
of the spatial frequencies. As a result, further optical effects can be
produced which
do not become visible until viewing the element from different angles or under
different angles of light incidence.
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[0033] The two procedure steps of embossing and printing for the production of
* the optically variable structure can be effected in any order. Thus,
at first the
embossed structure can be incorporated in the substrate of the data carrier
and
subsequently the coating be printed, or vice versa at first the coating is
printed and
subsequently the embossed structure incorporated in the substrate of the data
carrier. The two procedure steps can also be effected at the same time in a
joint
procedure step.
[0034] The information incorporated on the security element by the embossing
and the coating can consist of e.g. letters and/or numbers, but also any
symbols,
graphic elements or graphs, images, 1D- or 2D-codes or other patterns.
[0035] The substrate used for the security element can be of a single- or
multi-
layer design and can be coated, printed, pasted, lined, laminated or treated
otherwise
in a single- or multi-layer fashion at its surface or in the substrate. In
addition, in
and/ or to the substrate can be incorporated or applied further (also machine-
readable) security substances which upon the production of the first and/or
second
tilt image are activable, coverable, partially destructible or removable.
These further
security substances preferably produce a further tilt image here.
[0036] It shall be mentioned at this point that the security element may
consist of
any substrate suitable for the intaglio printing process. Paper and paper-like
substrates are especially preferred. No conditions are attached to the type of
the
paper so that usual papers made of fibers of annual plants, in particular
cotton fibers
or cellulose fibers, can be used. Likewise, papers can be used which at least
partially consist of plastic fibers, preferably polyamide fibers, i.e. which
contain a
portion of polymeric material approximately between 0 and 100 weight per cent.
The paper can also be combined on one side or on both sides with plastic
foils.
[0037] The paper layer usually has a weight of 50 g/m2 to 100 g/m2, preferably
70
g/m2 to 90 g/m2. Of course, depending on the application each suitable weight
can
be employed. The paper can be processed in a single-layer and also in a multi-
layer
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fashion. With multi-layer papers the paper layers may consist of the same or
of
different kinds of paper and again be combined with plastic foils.
[0038] Furthermore, it is thinkable that the substrate material is a plastic
foil, e.g.
a polyester foil. Furthermore, the foil can be stretched in a monoaxial or
biaxial
fashion. The stretching of the foil leads to the fact, among other things,
that it
receives polarizing properties which can be used as further security feature.
The
aids required for utilizing these properties, such as polarizing filters, are
known to
the person skilled in the art.
[0039] The foil may also be formed as a patch covering a partial surface of
the
substrate or as a strip extending over the entire length or width of the
security
document. As materials for the foil first of all plastic materials, in
particular PET
(polyethylene terephthalate), PBT (polybutylene terephthalate), PEN
(polyethylene
naphthalate), PP (polypropylene), PA (polyamide), PE (polyethylene), are
suitable.
Furthermore, the foil can be stretched in a monoaxial or biaxial fashion.
[0040] It may also be expedient when the substrate material is a multi-layer
compound which has at least one layer made of paper or a paper-like material.
Such
a compound is characterized by an extraordinarily great stability which is of
great
advantage for the durability of the security feature and, moreover, increases
the
forgery-proofness.
[0041] But it is also thinkable to employ a multi-layer, paper-free composite
material as substrate material. These materials can also be advantageously
employed in certain climate zones of the earth.
[0042] All materials employed as substrate material may have additives which
serve as authenticity features. Here first of all luminescent substances are
taken into
consideration which in the visible wavelength range preferably are transparent
and
in the not visible wavelength range can be excited by a suitable aid, e.g. a
UV- or
IR-radiation emitting radiation source so as to produce a luminescence that is
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visible or at least detectable with aids. Other security features can also be
employed
advantageously, provided they do not or only slightly impair the viewing of
the
print.
[0043] Below/on top of the tilt-image elements there can be located further
layers
which represent a pattern or image, but substantially are adjusted in an areal
fashion
or to the present grid of the tilt image. In this way e.g. upon a straight top
view the
eye of the viewer may be distracted from the actual tilt information which
then does
not become distinct until the tilting.
[0044] The steepness of the flanks and of the first and second embossed
elements
influences the tearing behavior of the substrate. The steeper the particular
flanks are
formed, the stronger the substrate is embossed and extended in this area, so
that
reduction of the thickness of the substrate and thus of the tearing behavior
occurs.
[0045] In addition, the angle between the longitudinal direction of the first
embossed structure and the printing cylinder of the printing machine
influences the
danger of a paper injury during the manufacturing of the security element.
Thus, an
angle of 00, i.e. the longitudinal direction of the first embossed structure
is aligned
in parallel to the printing cylinder, involves a special danger of paper
injury. But,
however, it leads to an especially preferred tilting behavior, since the
security
element, e.g. a bank note, does not have to be rotated around the axis towards
the
viewer to directly obtain a tilt image. Therefore, an angle of approximately
10 or
approximately 45 is preferably used. If the first embossed elements are not
formed
straight but for example wave-shaped, the longitudinal direction of the first
embossed elements refers to the average longitudinal direction of the first
embossed
elements.
[0046] The embossed structures according to the invention are produced by an
embossing tool having first recesses in which at least partially are
incorporated
second recesses. Here the second recesses either are incorporated in the first
recesses by a partial change of the geometry of the first recesses or are set
in each
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case on a flank of the first recesses at a given angle, so that they
correspond with the
particular embossed structures of the security element.
[0047] Preferably, the embossing tool is an embossing die or a printing plate,
in
particular an intaglio printing plate, the recesses of which are formed as a
gravure in
the surface of the embossing tool. The cross-sectional area of the gravures
here is
designed triangular, trapezoidal, sinusoidal or semicircular.
[0048] Especially preferred, the first and second recesses are incorporated
with a
graver and/or with a laser and/or with an etching method in separate processes
or in
one process in the surface of the embossing tool. The depth of the recesses
here
amounts to approximately 50% of the width of the recesses, in particular 10
[tm to
250 pm, preferably 50 p.m to 120 pm and especially preferably 60 in to 100
m.
100491 The graving tool is responsible for the flank steepness here. Thus, it
is
possible by a variation of the engraving tool by way of example in the
simplest
fon-n for the right flank to be processed with a separate tool having a steep
angle,
and the left flank to be given a wide flat flank run-out with a flat tool.
[0050] The substantial advantage of the invention is the creation of an
integrated
additional information in the form of a second tilt effect, which is produced
by a
second embossed structure within the flanks or on the flanks of the first
embossed
elements. This additional information can be additionally supported by a
suitable
arrangement of the coating. According to the invention, thus a clear
allocation of a
second information is effected within the embossed geometry of the first
embossed
structure. By the special structure of the coating and the second embossed
structure
within the first embossed structure a viewer perceives a change of the
interaction
against the surroundings.
[0051] Advantageously, thus, security elements for data carriers are provided
which combine two tilt effects with each other and can be manufactured with
the
machine standards and speed standards of a typical printer shop.
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[0052] Further advantages of the invention are the realization of linear or
nonlinear color shift effects as well as the implementation of many color
combinations by using or partially using existing colors within the data
carrier
manufacturing. In addition, a good perceptibility of the tilt effects
according to the
invention results for a man on the street or a consumer without aids.
[0053] The security element according to the invention in particular serves to
increase the forgery-proofness of documents of value, such as for example bank
notes, checks, share certificates, identity documents, admission tickets,
tickets,
deeds, credit cards, check cards and the like.
[0054] The optically variable structure according to the invention is
combinable
in particular within a document of value with any other security feature.
Thus, the
optically variable structure according to the invention can be arranged for
example
on top of a security thread, be combined with a hologram or other diffractive
structures or be disposed beside or overlapping with other optically variable
structures.
[0055] With reference to the following examples and complementary Figures the
advantages of the invention and various preferred embodiments of the invention
are
explained. The following Figures schematically show in detail:
[0056] Fig. 1 shows an optically variable structure according to the
invention
which consists of a first embossed structure in which is
incorporated a second embossed structure,
[0057] Fig. 2 shows a combination of coating and embossed structure by the
example of three first embossed elements,
[0058] Fig. 3 shows a combination of coating and embossed structure by the
example of a large-surface arrangement of first embossed
elements,
CA 02694383 2010-01-25
[0059] Fig. 4 shows different views of the combination in Fig. 3 from
different viewing directions,
[0060] Fig. 5 shows different embodiments of single- and multi-colored
coatings.
[0061] For clarity's sake the embodiments described in the following examples
are reduced to the substantial core information and the representations in the
Figures are strongly schematized and do not reflect the actual realities.
Primarily,
the proportions shown in the Figures do not correspond to the dimensions
present in
reality and exclusively serve for the improvement of clarity. In practical
application
substantially more complex patterns or images in single- or multi-color
printing can
be used as a coating. The same applies to the embossed structures. The
information
represented in the following examples can also be replaced by image
information or
text information as elaborate as desired.
[0062] The examples represent preferred embodiments to which, however, the
invention shall be in no way restricted. In particular, the various
embodiments are
not restricted to being used in the described form, but can also be combined
with
one another to enhance the effects.
[0063] Fig.1 shows an optically variable structure according to the invention
which consists of first embossed elements 1 in which is incorporated a second
embossed structure. A single first embossed element 1 has a triangular cross-
sectional area so that the embossed element 1 assumes the form of a horizontal
wedge with two oblique flanks. In particular the two flanks have different
colors.
[0064] According to Fig. la to lc the second embossed structure 2 is
incorporated
in the first embossed element 1 by a partial change of the geometry of the
first
embossed element 1.
[0065] According to Fig. 1 a the second embossed structure 2 is incorporated
in
longitudinal direction as modulation of the height of the first embossed
element 1.
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The upper edge of the first embossed element 1 here has wave-shaped
indentations,
so that in the area of the indentations the inclination of the flanks is
reduced. If light
falls perpendicular from above on the first embossed element 1, it impinges on
differently strong inclined flanks and thus is reflected in different angle
ranges. The
tilt effect upon tilting the security element around the longitudinal axis of
the first
embossed element 1 thus turns out to be differently strong along the
longitudinal
axis.
[0066] According to Fig. lb the second embossed structure 2 is incorporated in
transverse direction as modulation of the height of the first embossed element
1.
Here in certain areas the upper edge of the first embossed element 1 is
flattened.
This flattened area can have e.g. a color different from that of the flanks,
so that
upon tilting the security element around the longitudinal axis of the first
embossed
element 1, in addition to the tilt effect of the flanks, upon plan view onto
the
flattened area its color will appear. In the areas of the optically variable
structure,
however, in which no second embossed structure 2 is located, upon tilting the
security element around the first axis the viewer sees merely the two flanks
of the
first embossed structure 1, i.e. only the first tilt effect occurs.
[0067] According to Fig. lc the second embossed structure 2 is formed as notch-
like indentation at the point of the wedge in longitudinal direction of the
point. The
embossed structure 2 here forms a longitudinal groove in parallel to the upper
edge
of the first embossed element 1. The flanks of the indentation or longitudinal
groove
have a color which contrasts to that of the adjoining flank of the first
embossed
element 1. Upon tilting around the first axis a viewer thus first sees the
first flank of
the first embossed element 1 and approximately at the end of the first viewing
angle
range additionally the first flank of the indentation which extends in
parallel or
nearly in parallel to the first flank of the first embossed element. Upon
further
tilting around the first axis the viewer also sees the second flanks of the
first
embossed element 1 and of the indentation, until finally at first the first
flank of the
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first embossed element 1 and subsequently the second flank of the indentation
are
concealed by the second flank of the first embossed element.
[0068] According to Fig. ld to lg the second embossed structure consists of
second embossed elements 3, 4, 5, or 6 which are set in each case on a flank
of the
first embossed element 1 at a given angle. The second embossed element can be
designed by way of example as
quadrant- or quarter-ellipse-shaped embossed element 3 according to Fig.
ld, any other segments or parts of a sphere or ellipse also being possible,
wedge-shaped embossed element 4 according to Fig. le which stands on
its cross-sectional area and with a flank adjoins the first embossed
element,
pyramidal embossed element 5 according to Fig. lf or
wedge-shaped embossed element 6 according to Fig. lg which stands on
one of its three flanks and with its cross-sectional area adjoins the first
embossed element.
[0069] Here the second embossed elements 3, 4, 5, or 6 can be disposed with
their
longitudinal axis perpendicular, such as shown e.g. in Fig. lg, or also
oblique at any
angle to the longitudinal axis of the first embossed element 1.
[0070] Fig. 2 shows a combination of coating and embossed structure by the
example of three first embossed elements 1. The upper image of Fig. 2a and
Fig. 2b
shows the coating, the central image the combination of coating and embossed
structure in side view and the lower image the combination of coating and
embossed structure in view from obliquely above.
[0071] The coating is formed, according to Fig. 2a, as continuous strips 8
which
are aligned in parallel to the longitudinal axis of the first embossed
elements 1, and
as discontinuous strips 7 which are formed in parallel to the longitudinal
axis of the
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second embossed elements 4. The discontinuous strips 7 are printed onto a
flank of
the second embossed elements 2 and the continuous strips 8 are printed onto
that
flank of the first embossed elements 1 which is located opposite the second
embossed elements 4. Alternatively, the coating can also be formed, according
to
Fig. 2b, as continuous strips 9 which are aligned in parallel to the
longitudinal axis
of the second embossed elements 4. The continuous strips 8 are printed without
spacing onto a side of the flanks of the second embossed elements 2, the flank
of
the first embossed elements 1 which is located opposite the second embossed
elements 4 remains free.
[0072] Thus, the result is an additional tilt effect upon rotating the
security
element around its vertical axis, i.e. the axis which stands perpendicular on
the
surface of the security element. In an angle range merely the flank of the
second
embossed elements 4 printed with the discontinuous strips 7 or the continuous
strips
9 is visible, in a different angle range merely the not printed flank.
[0073] Fig. 3 shows a combination of coating and embossed structure by the
example of a large-surface arrangement of first embossed elements
corresponding
to Fig. 2a. Here, according to Fig. 3b to Fig. 3d, to a coating in the form of
a
background print 10 is allocated a first embossed structure in the form of
first
embossed elements 1. The second embossed structure in the form of second
embossed elements 4 shows additional information 11 which in this embodiment
is
formed as a rectangle or number or letter õI". Fig. 3e shows a single
optically
variable element as a detail from Fig. 3d.
100741 For a viewer who views the optically variable structure according to
Fig.
3, now according to Fig. 4 from different viewing directions A, B and C
different
views are rendered. Thus, according to Fig. 4b from viewing direction A there
is
recognizable a continuous horizontal strip 8 on the flank of the first
embossed
structure 1 and from viewing direction B a regularly disposed pattern of
discontinuous strips 7 and spacings which is also continued on the flanks of
the
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second embossed structure 4 disposed in the first embossed structure 1. From
viewing direction C on the flank of the first embossed structure 1 there is
further
recognizable the regularly disposed pattern of discontinuous strips 7 and
spacings.
On the flanks of the second embossed structure, however, when viewed from this
viewing direction there is located no print, so that in this area there is
visible a gap
in the form of the additional information 11.
[0075] In Fig. 5 there are shown different embodiments of single- and multi-
colored coatings. The colored coating here due to reasons of representation is
realized in different grey scale values and hatchings. The schematic
representation
thus can vary in color, have more filigree elements, e.g. micro lines or also
points,
fragments or special characters. An embodiment could represent the black
surface
as primary color cyan, the grey surface magenta and the hatched surface
yellow. A
limitation of the colors does theoretically not exist.
[0076] Fig. 5a here shows a single-colored coating which is formed as single-
colored strips with a grid distance X and a width smaller than the grid
distance X.
Between the individual strips there is no color applied, so that in these
areas the
color of the substrate emerges.
[0077] In Fig. 5b the coating is formed by an alternating sequence of two, in
Fig.
5f of three differently colored strips. The grid distance of the strips is
larger than the
width of the strips, so that between the individual strips there is a gap. In
each of the
gaps between the individual strips there is no color applied, so that in these
areas the
color of the substrate emerges. In Fig. 5c and Fig. 5e there is no gap between
the
individual strips, so that the individual strips adjoin each other.
[0078] In Fig. 5d and Fig. 5g the multi-colored coating is formed by a single-
colored background print, on top of which is printed a single-colored line
pattern
according to Fig. 5a or a multi-colored line pattern according to Fig. 5b.
CA 02694383 2010-01-25
[0079] Fig. 5h and Fig. Si, however, show a multi-colored background print
_
according to Fig. Se or Fig. 5f, on top of which is printed a single-colored
strip-
shaped coating corresponding to Fig. 5a.
[0080] In Fig. 5j there is finally shown a coating which is formed from an
alternating sequence of strips and pattern elements, such as circles and
rectangles.
