CN105437822A - Optically variable security element having reflective surface area - Google Patents

Abstract

The invention relates to an optically variable security element (12) for securing valuable articles, comprising a support with a reflective surface area (20), the extent of an x-y plane and defines a perpendicular thereto z-axis. According to the invention it is provided that - the reflective surface area (20) includes a plurality of reflective pixels (30) each having one or more, same oriented reflective facets (32), wherein an inclination of each facet (32) against the xy level is determined by the indication of their normalized normal vector - the reflective surface area (20) having a direction indicated by the x-axis preferred orientation, so that more than 80% of the facets (32) of the surface region (20) lying one in the yz plane have normal vector, and - at least a part of the facets (32), and is provided with a diffractive grating pattern (34) from a plurality of grid lines (36) whose grating vector is parallel to the x-axis.

Description

There is the safety element of the optically-variable in reflexive region

Technical field

The present invention relates to a kind of safety element of the false proof optically-variable for valuables, this safety element has carrier, and this carrier has reflexive region, and the stretching, extension in this reflexive region defines x-y plane and perpendicular z-axis line.The invention still further relates to a kind of method for the manufacture of this safety element and a kind of information carrier correspondingly equipped.

Background technology

The information carrier of such as paper representing value or identity document; or other valuables of such as brand article are typically provided with safety element to obtain safeguard protection; it makes it possible to the authenticity of checking information carrier, and is used as the unallowed protection copied simultaneously.

Safety element is worked in authenticity safeguard protection by the effect relevant to viewing angle, because these effects itself do not copy by state-of-the-art duplicator.Safety element is equipped with optically transformable element at this, and it passes on different image impression to observer under different viewing angles, and such as angle and different colors or brightness impression and/or different graphic theme are shown according to the observation.

Recently, the safety element of the kinematics/relief painting effect had on micro-mirror structure basis is usually used.Typically, micro-mirror structure itself does not produce color effect due to the micromirror size of micro mirror more than 5 μm, but color can be provided by (farbkippende) coating that is additional, that tilt colour developing.This tilt the generation of coating of colour developing normally realized by vacuum deposition method, and be therefore consumption cost consuming time.In addition, the bandwidth of possible color effect is also limited.Therefore, the color change of the coating of colour developing of such as tilting is always isotropic, namely has nothing to do with the incline direction of safety element.

Summary of the invention

Based on more than, task of the present invention proposes a kind of beginning to mention the safety element of the optically-variable of type, and it can be equipped with the structure of colour developing inexpensively.Ideally, this colour developing structure also has noticeable optical impression figure, and imparts higher antifalsification for safety element.

Be provided with in this type of safety element according to the present invention:

-reflexive region comprises multiple reflexive pixel, it has reflexive indentation face (Facetten) of one or more same orientation respectively, wherein, the normal vector that each indentation face is normalization (normalisiert) by providing it relative to the slope of x-y plane is determined

-reflexive region has the principal direction provided by x-axis line, thus described region more than 80% indentation mask have the normal vector being arranged in y-z plane, and

-at least partially indentation face be provided with the diffractive grating pattern be made up of multiple grid stroke, the grating vector of this grating pattern is parallel to x-axis line.

The selection of X-axis line or mentioned principal direction is not arbitrary at this, but is limited uniquely in the following way, that is, region, face more than 80% indentation mask have the normal vector being positioned at y-z plane (namely perpendicular to the plane of principal direction).As elaborated below, safety element provides two different gap tilt effects by the trend of the orientation in the indentation face in region, coordination face and the grid stroke of diffractive grating pattern, it occurs around orthogonal tilt axis when safety element tilts, and these two tilt axis are advantageously completely independent of one another.Especially, around the impression occurring kinematics effect during x-axis line inclination safety element as the first gap tilt effect, this kinematics effect is not attended by the gap tilt effect of color change, i.e. color science in favourable configuration, and around the impression occurring the second gap tilt effect during y-axis line inclination safety element, i.e. color science effect, it is pure, not with movement effects color change.

At this, the grating vector of grating pattern is perpendicular to the vector of grid stroke as usual, and its numerical value gives screen periods.

Especially, the indentation face at least partially with the normal vector being arranged in y-z plane is provided with the diffractive grating pattern be made up of multiple grid stroke, and the grating vector of this grating pattern is parallel to x-axis line.

Reflective pixel preferably comprises the indentation face of two or more same orientation respectively, but it is possible that one part of pixel or all pixels all only comprise an indentation face.Pixel and/or indentation face are advantageously configured to the profile with theme form, especially symbol or character forms at least partially.These special profiles can be used as additional authentication feature, and this authentication feature is only visible when amplifying.In addition, micro text can additionally be write in one part of pixel or indentation face.Micro text not only writes on indentation face at this, or also more alternative indentation faces are presented on carrier.

In a preferred embodiment, all grid strokes being provided with the indentation face of diffractive grating pattern all have the grating vector being parallel to x-axis line.Diffractive grating pattern advantageously has the screen periods between 0.3 μm and 4 μm, preferably between 0.6 μm and 3 μm.

In a favourable modification of the present invention, all grating patterns in region, face all have identical screen periods.As an alternative, the screen periods in each indentation face also can be chosen as different, but the gap tilt effect of kinematics and color science is partly coupled to each other thus.When tilting around x-axis line, (being correspondingly illuminated) indentation face with different screen periods also produces different diffraction colors, thus also additionally occurs color change or color science effect during kinetic effect.At this, color science effect and can't help bending light propagation plane change and produce, as elaborated below, but based on the conditioned reflex for these indentation faces change and produce.On the contrary, also only trigger color science effect in this case when tilting around y-axis line, and not triggered motion effect, thus orthogonal gap tilt effect not fully, but only partly coupled to each other.

Indentation face is preferably configured to flat panel element substantially.In this statement " substantially " it is considered that true as follows, that is, completely flat panel element cannot be produced due to the restriction of manufacturing condition in practice.As an alternative, these indentation faces also can be built into bending, especially recessed, that protrude or wavy panel element.So normal vector is along with the face extension change of panel element, but is in all the time in y-z plane.Usually, indentation face can be described by indentation face area h (x, y) provided, and wherein, smooth indentation mask has

H ₁(x, y)=c*y+c ₀, wherein (x, y) ∈ B

The indentation face area of form, wherein c and c ₀be constant, B is the coherent region of x-y plane.Bending indentation face has the indentation face area of following form usually:

H ₂(x, y)=f (y), wherein (x, y) ∈ B

It has only relevant to y smooth function f (y).

In a suitable embodiment, reflexive indentation face is arranged in and periodically especially forms sawtooth grating in net grid or grid.As an alternative, reflectivity indentation face is aperiodically arranged, wherein at this moment the aperiodicity in indentation face arranges it is preferred, because can avoid the undesirable diffracting effect of the regular layout coming from indentation face thus.

For suppressing another possibility of undesirable diffracting effect to be, in its height on region, face, ground offsets each other aperiodic in indentation face.When indentation face aperiodic offset between the height in adjacent indentations face, there is not simple, regular association, thus reliably avoid the constructive interference of the light that adjacent indentations face is reflected and reliably avoid the diffraction pattern forming superposition thus.The details that this aperiodicity offsets can obtain from document WO2012/055506A1, and its disclosure in this has been combined in the application.

Indentation face advantageously have in the principal direction provided by x-axis line 10 μm or more greatly, preferably 20 μm or more greatly, particularly preferably 30 μm or larger size.On the y direction vertical with principal direction, indentation face advantageously has the size between 5 μm and 30 μm, preferably between 7.5 μm and 15 μm, and indentation face highly advantageous between 0 and 10 μm, preferably between 0 and 5 μm.

Reflectivity indentation face has metal coating or high refractive index coating in favourable configuration.Reflexive indentation face but the coating of inclination variable color can also be had.

Reflexive region can be divided at least two sub regions, and indentation mask has different average orientations wherein, and when tilting around x-axis line, image impression changes suddenly thus, and forms so-called flipchart (Flip-Bild) thus.The orientation in indentation face also can have continually varying distribution at least one subregion in reflective surface region.Can produce arching effect in like fashion, wherein the arching of three-dimensional template is followed in reflective surface region.When tilting around x-axis line, the rotation of diffraction plane causes relief painting effect, wherein form reflection with the impression on the surface of arching.When tilting around y-axis line, the color of the mirror-reflection be conditioned and/or Strength Changes.

Advantageously, the orientation in indentation face is coordinated with each other for making safety element, when tilting around x-axis line, movement effects is shown, especially (orthoparallaktischen) movement effects of positive parallax or relief painting effect.

In the favourable embodiment of the present invention, a part of indentation face is configured to does not have diffractive grating pattern.Superstructure can be provided in like fashion it is with or without the different slope characteristic in the indentation face of grating pattern and is formed by tool.

In an advantageous embodiment, all indentation faces in region, face all have the normal vector being arranged in y-z plane.As an alternative, in a same favourable embodiment, the smaller scale in region, face, be less than 20%, be especially less than the indentation mask of 10% have normalized, be not the normal vector of the x component of 0 with Stochastic choice substantially.At this, the indentation face with the x component not being 0 is configured to does not have diffractive grating pattern.The indentation face of random inclination is respectively colourlessly shinny and produce visually attracting flash effect thus under specific obliquity, and it is superimposed on described orthogonal gap tilt effect.

Safety element can also comprise reflexive region of two or more described type, its grating constant preferably by the incline direction be labeled and/or grating pattern and different.Especially, each reflective surface region of safety element can have oneself, the principal direction that provided by the x-axis line in region, face.Such as, safety element has the reflective surface region of two described types, and their principal direction provided by the x-axis line in region, corresponding face is perpendicular to one another.When around one of principal direction inclination safety element, then one of region, two faces illustrates pure kinematics gap tilt effect, and another side region illustrates pure color science gap tilt effect.When tilting around orthogonal principal direction, the role swap in this region, two faces.

Alternatively or additionally, safety and case can comprise the reflective surface region of two or more described type, and wherein, in each region, all grating patterns have identical screen periods, and the screen periods in coplanar region is not different.

Described reflective surface region can be combined with other security feature, such as with hologram, especially realistic colour hologram combination, combine with sub-wave length grating or other sub-wavelength structure, combine with there is no the micro-mirror device of diffractive grating, or also combine with the security feature based on special material characteristic such as electric conductivity, magnetic, cold light, fluorescence etc.Other security feature such as can be located in the gap in reflective surface region or with it and interlock.

It is finally to be noted that, illustrated condition, namely, the normal vector in indentation face is arranged in y-z plane and grating vector is parallel to x-axis line, not must or can mathematically accurately meet at that time for the structure of reality, but will be understood that for those skilled in the art, with these mathematically accurate condition little, such as in manufacturing technology, unescapable deviation does not affect the functional of described gap tilt effect and safety element.

The present invention also comprises the information carrier of the safety element with described type.Information carrier especially can be paper representing value, such as banknote, especially bill, polymer banknote or membrane complex banknote, it is the admission ticket of stock, receipt, certificate, coupons, check, high value, but also can be certificate card, such as credit card, bank card, Payment Card, proof card, identity card or passport individual page.

The present invention also comprises a kind of method describing the safety element of the optically-variable of type for the manufacture of beginning, wherein

-carrier is provided and is provided with reflective surface region for described carrier, the stretching, extension in this region, face defines x-y plane and perpendicular z-axis line,

-wherein, reflective surface region is configured to has multiple reflective pixel, these pixels have the reflectivity indentation face of one or more same orientation respectively, and wherein each indentation face is that normalized normal vector by providing it is determined relative to the slope of x-y plane

-reflective surface region is produced as the principal direction having and provided by x-axis line, make region, face more than 80% indentation face all there is the normal vector being arranged in y-z plane, and

-at least partially indentation face be provided with the diffractive grating pattern be made up of multiple grid stroke, its grating vector and x-axis line parallel.

In order to manufacture security element according the invention, can such as by gray-level light lithography, reflectivity indentation face be carved in photoresist together with diffractive grid pattern, next rinse, plating is out of shape, be pressed in UV paint and mirror-polishing.Mirror-polishing such as can pass through metal level that is applied, such as evaporation and realize.Typically applying to have at this is such as the aluminium lamination of the thickness of 50nm.Certainly other metal can also be used, such as silver, copper, chromium, iron, nickel or its alloy.Alternative in metal also can apply a semiconductor such as silicon, by ZnS, Al ₂o ₃or TiO ₂the coating of the high refractive index coating made or inclination variable color.Apply, especially evaporation can carry out by entire surface, but also possibly only perform by region or the coating of grill-shaped, thus safety element is partly transparent or translucent.

Accompanying drawing explanation

Set forth other embodiments of the invention and advantage by accompanying drawing below, what wherein do not use perspec-tive and size illustrates mode, to improve clearness.Wherein:

Fig. 1 is the schematic diagram of banknote, this banknote have with wider safe strips, according to the safety element of optically-variable of the present invention,

Fig. 2 correspondingly schematically shows for a section of the safety element of Fig. 1 the impression figure that observer perceives under the different obliquity of safety element,

Fig. 3 schematically shows the details fragment in the reflective surface region of security element according the invention with top view,

Fig. 4 shows the perspective view of two pixels on the left hand edge of the details fragment of Fig. 3,

Fig. 5 shows the fragment in the reflective surface region of security element according the invention, and wherein each pixel is made up of only indentation face and wherein pixel or indentation face are aperiodically arranged in an x-y plane,

Fig. 6 shows the cross section in the reflective surface region according to another form of implementation of the present invention,

Fig. 7 shows safety element, and its reflective surface Region dividing is two sub regions, and in them, indentation face has different average orientations respectively, and

Fig. 8 a and Fig. 8 b respectively illustrates the safety element with multiple reflective surface regions, and its difference is main incline direction or the grating constant of grating pattern.

Detailed description of the invention

Set forth the present invention by the example of the safety element for banknote now.Fig. 1 shows the schematic diagram of banknote 10 to this, its have wide safe strips, according to the safety element 12 of optically-variable of the present invention.But will be understood that, the present invention is not limited to safe bar and banknote, but can use in all types of safety element, such as, in the label of kinds of goods and packaging or in the security element of file, certificate, passport, credit card, medical insurance card etc.In banknote and similar file, except safety bar, such as also consider safety line or transfer element.

Safety element 12 shown in Figure 1 shows two different gap tilt effects, they tilting 14 around orthogonal tilt axis, 16 safety element time occur, and they are completely independent.In order to describe, these are orthogonal, independently gap tilt effect, and additionally with reference to figure 2, its section for safety element 12 schematically show the impression figure by observer's perception under the different obliquities of safety element 12.

The safety element 12 of optically-variable comprises reflexive region 20, and its stretching, extension defines x-y plane, and this plane overlaps on this surface with banknote 10.The x of X-y plane and y-axis show two by the incline direction marked at this, wherein only occur one of two orthogonal gap tilt effects respectively when being tilted around these by one of axis of marking.In this embodiment, x-axis line along banknote 10 longitudinal edge extend and y-axis line extends along horizontal seamed edge.Therefore, banknote inclination 14 forward or backward shows the inclination around x-axis line, and below in order to clearness reason is also referred to as " north and south inclination ".Banknote to the right or the inclination 16 on a left side show inclination around y-axis line, and below also referred to as " thing inclination ".Z-axis line perpendicular to x-y plane, thus defines right-handed coordinate system by the coordinate system that these three axis are formed.

Region, face 20 shows so-called cube of cylinder pattern (RollingCube-Muster), wherein can see the little rectangle 22 that two row are parallel in each obliquity, it has specific distance to each other and with specific color impression, such as occur with the color impression of redness as set forth in Fig. 1.

Make banknote around in the north and south inclination 14 of the inclination of x-axis line, i.e. safety element 12, first gap tilt effect in gap tilt effect mentioned by two occurs, i.e. kinematics effect, wherein two rectangle row 22 colors unchangeably along Fig. 1 arrow 24 in opposite directions or opposing liftoff movement.

When banknote tilts around y-axis line, namely the thing of safety element 12 tilts in 16, and the second gap tilt effect occurs, i.e. color science effect, and wherein rectangle row 22 do not change its compartment of terrain and change its color, such as, change between red and green.

These two gap tilt effects are called orthogonal, because they occur when tilting around orthogonal sloping shaft 14,16.These two gap tilt effects are completely independent in addition because tilt around x-axis line 14 time only there is kinematics effect and do not occur color science effect, and tilt around y-axis line 16 time only there is color science effect and do not occur kinematics effect

Fig. 2 shows the impression figure of safety element 12 before and after different inclinations 14,16.At this, from the impression figure of Fig. 1, it is depicted as impression Figure 26-A on the upper left side of Fig. 2, and it illustrates the rectangle row 22 with large interval and red color impression.

The north and south inclination 14 of banknote 10 causes the impression Figure 26-B shown in Fig. 2 lower left, and wherein color is unchangeably towards moving each other for observer for rectangle row 22, and namely present have less interval under constant red color impression.By back tilting, rebuild original impression Figure 26-A.If trigger from impression Figure 26-A on the contrary and perform thing inclination 16, then rectangle row 22 change their color, such as, become green from redness, and the interval of the position of rectangle and rectangle row 22 remains unchanged.Impression Figure 26-C shown in Fig. 2 upper right side has the large interval of rectangle row 22 and green color impression.If perform north and south to tilt 14 from this obliquity, then rectangle row 22 again color move in opposite directions unchangeably, thus form the impression Figure 26-D shown in lower right, wherein rectangle has little interval under being listed in green color impression.Another (and the first thing tilts contrary) thing tilts the 16 impression Figure 26-B it being got back to have little interval and red color impression.

Will be understood that, the interval variation of rectangle row 22 and color change are continuous print in practice and are only only confined to two spacing values and two color impressions in order to diagram in fig. 2.

In addition, from described functional also obtain, the inclination carried out around the axis do not overlapped with x or y-axis line can cause the gap tilt effect of combination, and it not only has kinematics and also has color science component.The tilt axis that x and the y-axis line orientation in the plane in region, face 20 passes through marked inclination 14,16 just limits, and wherein occurs pure kinematics effect (tilting 14) or pure color science effect (tilting 16).In this embodiment, the tilt axis marked is parallel with the seamed edge of banknote 10 with safety element 12, but usual marked tilt axis has the arbitrary orientation relative to safety element.

The structure of security element according the invention and two orthogonal, independently the formation of gap tilt effect elaborate with reference now to Fig. 3 and 4.At this, Fig. 3 schematically shows the details fragment in the reflective surface region of security element according the invention with top view, and Fig. 4 shows the stereogram of two pixel 30-A on the left hand edge of the details fragment of Fig. 3,30-B.

The reflective surface region 20 of security element according the invention is made up of multiple reflective pixel 30, wherein in the detail view of Fig. 3 and 4, illustrate only some of them.Pixel is configured to the profile with rectangle in this embodiment, but they also usually can have other contour shape, especially have the theme shape of such as symbol or mark.The seamed edge length of pixel 30 below 300 μm, and is especially arranged in the scope of 20 μm to 100 μm.

Each reflective pixel 30 comprise one or more, be 2 reflectivity indentation faces with same orientation in this embodiment.The length in indentation face 32 and width are positioned at more than 5 μm, to avoid arranging by indentation face the color divergence caused.The length (size in the x direction) in indentation face is preferably greater than 10 μm, is especially greater than 20 μm, and the width (size in y-direction) in indentation face is advantageously between 7.5 and 15 μm.When the indentation face of this size, obtain clearly diffraction color by grating pattern described below.

The orientation in indentation face 32, namely especially indentation face, relative to the slope of x-y plane, is the normalized normal vector n by providing them ₀=(n _x, n _y, n _z) (wherein | n ₀|=1) and positive z component determine.Although the orientation of indentation face 32 in pixel 30 is always identical, they according to pixels distinguish in practice, to give observer one or more theme that is desired, that constructed by pixel 30 in different direction of observations.

According to the present invention, the major part in region, face 20, even the indentation face 32 of 100% all has the normal vector being arranged in y-z plane in the embodiment illustrated, i.e. the x component n of normal vector _xbe 0.Due to normalization, the normal vector in indentation face is by y component n _ydetermine uniquely and pass through relational expression

n _y＝sinγ

Associate with inclination angle γ, indentation face 32 is with x-y plane and surround this inclination angle (Fig. 4) with the macro surface of picture on surface 20 thus.

Reflexive indentation face 32 is also provided with diffractive grating pattern 34, and it is made up of multiple parallel grid stroke 36.For scanning property reason, only grid stroke 36 is marked for one of the indentation face of pixel 30-A in the diagram.The orientation of grid stroke 36 be chosen as within the scope of this invention make grating pattern 34, numerically determine grating vector g and the x-axis line parallel of screen periods according to definition perpendicular to grid stroke 36.Therefore grating vector can write g=(g usually _x, 0,0), wherein g _xit is screen periods.

The screen periods g of grating pattern 34 _xusual between 0.6 μm and 3 μm within the scope of this invention, and select so particularly, make to produce desired color effect in the tilt angle ranges of expectation given in advance.In this embodiment, all indentation faces 32 are had identical screen periods g _xidentical grating pattern 34 occupy.But substantially also possible that, for one part of pixel change screen periods, thus that kinematics effect and color science effect portion is coupled to each other, as set forth above.

The alternative statement that grating vector for grating pattern 34 should be parallel to the condition of x-axis line can realize with indentation face area h (x, y).Because gradient represent the direction of the greatest gradient of indentation facial plane, so also can should be expressed as about the condition of grating pattern 34, the tangent vector t that must be parallel to this greatest gradient at the grid stroke 36 at each some place in indentation face moved towards.

The tangent vector t of the greatest gradient of indentation face area is pass through for common indentation face area h (x, y)

$t(x,y)=(h_x/|\▿h|,h_y/|\▿h|,|\▿h\left|\right),$

Provide, wherein, $h_x=\∂h(x,y)/\∂x$ With $h_y=\∂h(x,y)/\∂y$ Represent partial derivative, and it is the gradient of indentation face area.

Because indentation face 32 has the normal vector being arranged in y-z plane according to the present invention, it usually passes through in normalized form

N ₀=n/|n|, wherein n=(-h _x,-h _y, 1)

Provide, so h _x=0 and the tangent vector of greatest gradient is arranged in y-z plane equally:

$t(x,y)=(0,h_y/|\▿h|,|\▿h\left|\right)$

For above mentioned smooth indentation face

H ₁(x, y)=c*y+c ₀, wherein (x, y) ∈ B

The tangent vector of greatest gradient has nothing to do with position, that is,

t ₁(x,y)＝(0,1,c)

And for the indentation face of general bending

H ₂(x, y)=f (y), wherein (x, y) ∈ B

Tangent vector for greatest gradient draws

₂(x,y)＝(0,f'(y)/|f'(y)|,|f'(y)|)。

If in order to explain that first kinematics effect observes the reflectivity indentation face 32 not having diffractive grating pattern 34, then these do not have the indentation face 32 of grating to play achromatic reflectivity micro mirror, and the light of incidence reflects according to geometric optics theorem by it under dispersionless condition.If meet conditioned reflex " incidence angle equals the angle of emergence " from a direction of observation in indentation face, then indentation face seems colourless shinny, otherwise is dark.Because conditioned reflex is only accurately met (under the condition that there is an only main light source) for an angle of inclination, so along obtaining unexpected, discrete brightness change during North and South direction inclination safety element.

Face pattern 20 has the multiple indentation faces 32 with different angle of inclination γ, and wherein the indentation face 32 of identical orientation is arranged so that shinny and dark indentation face generally for observing the theme presenting expectation.The normal vector in all indentation faces 32 is all arranged in y-z plane, thus conditioned reflex along during North and South direction inclination safety element 12 for all indentation faces 32 side by side and change with same degree.Conditioned reflex was met and shinny indentation face no longer can meet conditioned reflex and therefore seems dark after north and south tilts before inclination.On the contrary, be that dark indentation face can brighten after inclination suitably of tilting according to North and South direction before tilting.By arranging indentation face and its inclination angle suitably, the mobile effect of all expectations can be produced thus, especially also having the mobile effect of positive parallax.It is also possible for presenting relief painting effect.Possible mobile effect and the overall of relief painting effect are summarized as term " kinematics effect " in the scope of this description.

If add now diffractive grating pattern 34 to set forth color science effect, thus additionally must consider the diffraction of incident light on grating pattern, so substitute the direction of the folded light beam of geometric orientation and consider the direction of the Zero-order diffractive level of grating pattern.In the direction of Zero-order diffractive level, meet conditioned reflex " incidence angle equals the angle of emergence ", indentation face seems bright and colourless, although brightness does not typically have the situation of grating smaller than above-described, because a part of light has been diffracted on other direction in space.

In grating pattern 34, the direction of propagation of diffracted light is in the plane of being opened by grating vector g and the direction of Zero-order diffractive level.In this plane, grating equation is passed through in the direction of diffraction light

sinα+sinβ＝mλ/g _x

Provide, wherein m is the order of diffraction, g _xbe screen periods and λ is wavelength.Angle [alpha] or β be incident or in reflected light projects to the plane of being opened by grating vector g and normal vector n time angle.At this, angle [alpha] is always taken as positive at this, and angle beta as being positioned at and be positive during α the same side relative to grating normal common in configuration according to the present invention, otherwise is negative.

For specific direction of observation and the obliquity of safety element 12, such as shown in Fig. 1, so obtain the specific impression figure in region, face, this impression figure is determined by the diffracting effect of grating pattern 34 on the other hand by the angle of inclination in indentation face 32 on the one hand.

Tilt in north and south 14 safety element 12 time, when namely tilting around x-axis line, conditioned reflex changes for all indentation faces 32 simultaneously, thus the kinematics effect desired by being formed by the layout in indentation face 32.Due to being parallel to the grid stroke of y-z plane or being parallel to the special orientation of grating pattern 34 of grating vector g of x-axis line, the angle [alpha] of grating equation and β tilt in 14 in north and south and do not change.Therefore, the color impression in indentation face 32 remains unchanged in north and south inclination 14, and kinematics effect is not attended by color science effect.

On the contrary, due to the special orientation in indentation face 32, the thing of safety element tilts 16, namely do not change the light of institute's diffraction around the inclination of y-axis line, the propagation plane of being opened with the direction of Zero-order diffractive level by grating vector g, thus the unexpected and discrete change of the observability in each indentation face can't be there is when thing tilts, more precisely, there will not be the impression figure in space, the interval of the rectangle row 22 of such as Fig. 1 and 2 remains unchanged.

Thing inclination 16 extends in the diffraction plane of grating pattern 34, thus along with inclination, the angle [alpha] in grating equation and β gradually change.In thing tilts, therefore occur color and/or intensity gradual change, by this color and/or intensity gradual change, especially the color impression in indentation face 32 continuously changes.But because the impression figure in space remains unchanged, so this color science effect is not attended by kinematics effect.Generally, these two orthogonal effects are completely independent thus.

Reflective pixel 30 or reflectivity indentation face 32 can be arranged to the grid of rule as illustrated, and the balzed grating, of such as formation rule.According to of the present invention region however be not limited to rule pixel or indentation face arrange, more precisely, aperiodic or irregular pixel or indentation face is even preferably used to arrange, because avoid undesirable diffracting effect thus, the diffracting effect as can be formed by regular arrangement.

Fig. 5 shows an embodiment, the view wherein in order to simplify, and each pixel 30 is only made up of an indentation face 32, and wherein pixel or ground aperiodic, indentation face are arranged in an x-y plane.Although still obtain the region, face with clearly diffraction color in order to the difference in height having adjacent indentations face and the phase step be accompanied by this, indentation face is of a size of at least 10 μm, preferably at least 20 μm, particularly preferably at least 30 μm in x direction.In y-direction, the size in indentation face is between 5 μm and 30 μm, preferably between 7.5 μm and 15 μm.The height in indentation face is between 0 and 10 μm, preferably between 0 and 5 μm.

Another is for suppressing the possibility of undesirable diffracting effect to be by being divided into indentation face, and by indentation face, in its height on region, face, ground offsets each other aperiodic.Such as, Fig. 6 shows the cross section in the reflective surface region 40 of safety element 12, although the indentation face 42 wherein shown in fragment all has identical gradient, according to aperiodic, especially irregular mode with 0 to the skew from the initial position of its rule of the height offset at least between half-wavelength.Thus, change with the value between 0 and at least one complete wavelength brokenly at different differential (Gangunterschiede) between indentation face 42-j, 42-k.So light beam 44-j and 44-k reflected by different indentation face 42-j, 42-k is in random phase relation, although thus there is the periodic arrangement in the indentation face 12 of same orientation, the grid in indentation face 42 does not still play diffraction structure, and does not therefore occur interfering secondary diffracting effect.

Fig. 7 shows an embodiment, and wherein the reflective surface region 50 of safety element is divided into two sub regions 52,54, and wherein indentation face 32 has different average orientations respectively.Such as, indentation face 32 can have angle of inclination γ in the subregion 52 built with the form of numeral " 20 ", its Stochastic choice between 10 ° and 20 °, and indentation face 32 has angle of inclination γ in background area 54, its Stochastic choice between-10 ° and-20 °.When safety element tilts along north-south, so, according to obliquity, first or second subregion 52,54 seems bright and has color, thus numeral " 20 " conversion between positive diagram (numeral is bright, background is dark) and negative diagram (numeral is dark, background is bright), and form so-called flipchart.When tilting along east-west direction, plus or minus diagram remains unchanged substantially, but shows the color change of above-described color science effect.

Indentation face can also be located at has the first screen periods g _x1grating pattern subregion 52 in and be located at there is the second screen periods g _x2grating pattern subregion 54 in, although thus subregion 52,54 tilts in north and south time show constant, different color.

Safety element can also have the reflective surface region of multiple described type, and it is such as distinguished by the incline direction of mark or the grating constant of grating pattern.Fig. 8 a shows to explain has the safety element 60 that two describe the reflective surface region 62,64 of type above.Each region 62,64 defines x-y plane by its stretching, extension, is wherein shown as orthogonal tilt axis (namely for the x-axis line of kinematics effect and the y-axis line for color science effect) and have rotated 90 ° relative in region, face 62 in region, face 64.

As visible from diagram above, thus it is achieved that, indentation face in region, face 62 is orientated the normal vector of the y-z plane it be arranged in there, and the indentation face in region, face 64 is orientated and makes it have the normal vector in the y-z plane in region, face 64.Correspondingly, the mutual half-twist of orientation of the grid stroke in region, face 62,64, namely extends perpendicular to corresponding x-axis line.

When tilting around axis 66, safety element 60 has illustrated phoronomics gap tilt effect in region, face 62, because there inclination carry out around x-axis line.Meanwhile, safety element 60 has illustrated pure color science gap tilt effect in region, face 64, because there inclination 66 carry out around y-axis line.Correspondingly, safety element 60 has illustrated pure color science gap tilt effect in region, face 62 when tilting around axis 68, and in subregion 64, also show pure kinematics gap tilt effect.

The safety element 70 of Fig. 8 b comprises the reflective surface region 72,74 that two describe type above, and it has the identical tilt axis be labeled.But indentation face 32 is provided with the first screen periods g in region, face 72 _x1grating pattern 76, and in region, face 74, be provided with the second screen periods g _x2grating pattern 78, and therefore illustrate different diffraction colors.

When tilting around axis 66, safety element 70 has illustrated pure kinematics gap tilt effect in region, two faces 72,74, because tilt to carry out around x-axis line respectively.Correspondingly, safety element 70 has illustrated pure color science gap tilt effect when tilting around axis 68 in region, two faces 72,74, because tilt to carry out around y-axis line respectively.Due to screen periods g _x1and g _x2difference, diffraction color in region, two faces 72,74 is different, more precisely, the constant color impression when tilting around axis 66 and when tilting around axis 68 color impression of change all different.

Reference numerals list

10 banknotes

12 safety elements

14,16 tilt axis

20 reflective surface regions

22 little rectangles

The arrow of 24 moving directions

26-A to 26-D impression figure

30,30-A, 30-B pixel

32 reflectivity indentation faces

34 diffractive grating patterns

36 grid strokes

40 reflective surface regions

42,42-j, 42-k indentation face

44-j, 44-k reflectivity light beam

50 reflective surface regions

52,54 subregions

60 safety elements

62,64 subregions

66,68 tilt axis

70 safety elements

72,74 subregions

76,78 grating patterns

Claims (20)

1. for a safety element for the optically-variable of safeguard protection valuables, described safety element has carrier, and described carrier has reflexive region, and the stretching, extension in described reflexive region defines x-y plane and perpendicular z-axis line,

It is characterized in that,

-reflexive region comprises multiple reflexive pixel, these pixels have the identical reflexive indentation face of one or more orientation respectively, wherein, each indentation face is that normalized normal vector by providing it is determined relative to the slope of x-y plane

-reflexive region has the principal direction determined by x-axis line, make described region more than 80% indentation mask have the normal vector being arranged in y-z plane, and

-at least partially indentation face be provided with the diffractive grating pattern be made up of multiple grid stroke, the grating vector of described grating pattern is parallel to x-axis line.

2. safety element according to claim 1, is characterized in that, all grid strokes being provided with the indentation face of diffractive grating pattern all have the grating vector with x-axis line parallel.

3. safety element according to claim 1 and 2, is characterized in that, diffractive grating pattern has the screen periods between 0.3 μm and 4 μm, preferably between 0.6 μm and 3 μm.

4. safety element according to any one of claim 1 to 3, is characterized in that, all grating patterns in reflexive region all have identical screen periods.

5. safety element according to any one of claim 1 to 4, is characterized in that, indentation face is configured to smooth panel element substantially.

6. safety element according to any one of claim 1 to 5, is characterized in that, reflexive indentation face is arranged to periodicity grid and especially forms sawtooth grating.

7. safety element according to any one of claim 1 to 5, is characterized in that, reflexive indentation face is non-periodic arrangement.

8. safety element according to any one of claim 1 to 7, is characterized in that, indentation face relative to each other offsets in its height on described region.

9. safety element according to any one of claim 1 to 8, it is characterized in that, indentation face have in the principal direction determined by x-axis line 10 μm or more greatly, preferably 20 μm or more greatly, particularly preferably 30 μm or larger size, and/or indentation face has the size between 5 μm and 30 μm, preferably between 7.5 μm and 15 μm on the y direction vertical with described principal direction, and/or the height in indentation face is between 0 and 10 μm, preferably between 0 and 5 μm.

10. safety element according to any one of claim 1 to 9, is characterized in that, reflexive indentation mask has the coating of metal coating or high index of refraction.

11. safety elements according to any one of claim 1 to 10, is characterized in that, reflexive region is divided at least two sub regions, and in these subregions, indentation mask has different average orientations.

12. safety elements according to any one of claim 1 to 11, is characterized in that, the orientation in indentation face at least has continually varying trend in a sub regions in reflexive region.

13. safety elements according to any one of claim 1 to 12, it is characterized in that, the orientation mobile effect for making safety element that mobile effect, especially positive parallax are shown when tilting around x-axis line coordinated with each other in indentation face, or the effect of relief painting.

14. safety elements according to any one of claim 1 to 13, is characterized in that, a part of indentation face is configured to does not have diffractive grating pattern.

15. safety elements according to any one of claim 1 to 14, it is characterized in that, the indentation mask being less than 20%, being especially less than 10% in described region have with Stochastic choice substantially, the normalized normal vector that is not equal to the x component of 0, and these indentation faces with the x component being not equal to 0 are configured to and do not have diffractive grating pattern.

16. safety elements according to any one of claim 1 to 15, it is characterized in that, pixel is configured to the profile had with theme form, especially symbol or character forms at least partially.

17. safety elements according to any one of claim 1 to 16, it is characterized in that, safety element comprises two or more reflexive region according to claim 1, wherein each reflexive region there is oneself, the principal direction that provided by the x-axis line in described region, preferably, safety element comprises two reflexive regions according to claim 1, and their principal direction provided by the x-axis line in described region is perpendicular to one another.

18. safety elements according to any one of claim 1 to 17, it is characterized in that, safety element comprises two or more reflexive region according to claim 1, wherein, in each region, all grating patterns all have identical screen periods, but the screen periods in different regions, face is different.

19. 1 kinds of information carriers with the safety element according to any one of claim 1 to 18.

20. 1 kinds for the manufacture of according to any one of claim 1 to 18, the method for the safety element of optically-variable, wherein

-carrier is provided and reflexive region is set for it, the stretching, extension in this reflexive region defines x-y plane and perpendicular z-axis line,

-wherein, described reflexive region is configured to has multiple reflexive pixel, described pixel has reflexive indentation face of one or more same orientation respectively, wherein, each indentation face is that normalized normal vector by providing it is determined relative to the slope in the indentation face of x-y plane

-described reflexive indentation face is produced as the principal direction having and provided by x-axis line, thus described region more than 80% indentation mask have the normal vector being arranged in y-z plane, and

-at least partially indentation face be provided with the diffractive grating pattern be made up of multiple grid stroke, the grating vector of this grating pattern is parallel to x-axis line.