US Pat. No. 9,177,433

MOIRE MAGNIFICATION DEVICE

DE LA RUE INTERNATIONAL L...

1. A moiré magnification device comprising a transparent substrate carrying:
i) a regular array of micro-focusing elements on a first surface, the focusing elements defining a focal plane;
ii) a corresponding array of microimage element unit cells located in a plane substantially coincident with the focal plane
of the focusing elements, each unit cell comprising at least two microimage components;

wherein the pitches of the micro-focusing elements and the array of microimage element unit cells and their relative locations
are such that the array of micro-focusing elements cooperates with the array of microimage element unit cells to generate
magnified versions of the microimage components due to the moiré effect,

wherein in at least one of the unit cells comprising at least two microimage components, a first microimage component of the
unit cell has a color density different than the color density of the other, second microimage component,

and wherein a further colored layer is provided on or extending over the array of microimage element unit cells such that
when the device is viewed, at least the second microimage components appear in a color dependent at least partly on the further
colored layer and which is different from the color of the first microimage components.

US Pat. No. 9,070,237

MOIRE MAGNIFICATION DEVICE

DE LA RUE INTERNATIONAL L...

1. A moiré magnification device comprising a transparent substrate carrying:
i) a regular array of micro-focusing elements on a first surface, the focusing elements defining a focal plane; and
ii) a corresponding first array of microimage elements located in a plane substantially coincident with the focal plane of
the focusing elements,

wherein the pitches of the micro-focusing elements and the array of microimage elements and their relative locations are such
that the array of micro-focusing elements cooperates with the array of microimage elements to generate magnified version of
the microimage elements due to the moiré effect,

and wherein, along at least one axis across at least a first region of the device, the pitch between the microimage elements
and/or between the micro-focusing elements continuously varies across the respective array(s), whereby the moiré effect causes
different degrees of magnification of the image elements to occur, such that the viewer perceives that the magnified elements
are located on a first image surface which is tilted or curved relative to the surface of the device.

US Pat. No. 9,272,564

PHOTONIC CRYSTAL SECURITY DEVICE AND METHOD

DE LA RUE INTERNATIONAL L...

27. An optically variable security device comprising at least a first region and a second region that each region comprises
a photonic crystal material, whereby:
in the first region the photonic crystal material is configured such that incident light received by the photonic crystal
material is selectively reflected or transmitted by the photonic crystal material to generate a first optically variable effect
when illuminated and viewed under a predetermined set of conditions; and

in the second region the photonic crystal material is configured such that incident light received by the photonic crystal
material is reflected or transmitted by the photonic crystal material to generate an optical effect, different from the first
optically variable effect when illuminated and viewed under the same said predetermined set of conditions,

wherein:
one of the first region and the second region comprises an opal structure having a respective degree of crystal ordering;
and

the other of the first region and the second region comprises an inverse opal structure in which the degree of crystal ordering
is greater than or less than the degree of crystal ordering of the region comprising the opal structure.

US Pat. No. 9,348,070

SECURITY DEVICES

De La Rue International L...

1. A security device comprising:
a carrier substrate having a first surface;
a light deflection structure applied to at least a part of the first surface of the carrier substrate, the light deflection
structure having a first side and a second opposing side;

a colorshifting layer applied to the first side of the light deflection structure; and
a reflection layer applied to at least a first region of the second side of the light deflection structure so as to provide
a strong reflection in a direction substantially parallel to an incident light source when a direction of incident light of
the incident light source is at an angle away from the normal to the security device,

wherein the security device has at least one second region in which the reflection layer is absent, said first and second
regions defining indicia.

US Pat. No. 9,483,719

SECURITY SUBSTRATE COMPRISING A MAGNETIC LAYER AND OPAQUE AND NON-OPAQUE REGIONS

De La Rue International L...

1. A security substrate comprising a transparent polymer carrier layer, an indicia layer supported by the carrier layer, said
indicia layer comprising a plurality of opaque and non opaque regions which define indicia, and a transparent magnetic layer
supported by the carrier layer, said magnetic layer comprising a distribution of particles of a hard magnetic material having
a magnetic remanance in the absence of an applied magnetic field, said particles being of a size and distributed in a concentration
at which the magnetic layer remains transparent, wherein the magnetic layer contains between 0.1 and 50% by weight of magnetic
material, and wherein the magnetic layer covers at least some of the non-opaque regions of said indicia layer, and wherein
said transparent magnetic layer is out of register with said opaque and non-opaque regions of said indicia layer such that
said non-opaque regions of said indicia layer are only partially in register with said transparent magnetic layer.

US Pat. No. 9,429,762

SECURITY DEVICE

DE LA RUE INTERNATIONAL L...

1. A security device having a lenticular device, comprising:
a first image strip pair having a first and second image strip;
a second image strip pair having a third and fourth image strip;
a first portion of a first image in a first colour and a first portion of a second image in a second colour located in the
first image strip;

a second portion of the first image in the first colour and a second portion of the second image in the second colour located
in the third image strip;

a first portion of the first image in the second colour and a first portion of the second image in the first colour located
in the second image strip;

a second portion of the first image in the second colour and a second portion of the second image in the first colour located
in the fourth image strip;

a first lenticular focusing element located over the first image strip pair;
a second lenticular focusing element located over the second image strip pair;
wherein:
the first and third image strips are different from each other;
the second and fourth image strips are different from each other;
in a first viewing direction, the first and third image strips are viewed by the first and second lenticular focusing elements,
the first image is viewed in the first colour, and the second image is viewed in the second colour; and

in a second viewing direction, the second and fourth image strips are viewed by the first and second lenticular focusing elements,
the first image is viewed in the second colour, and the second image is viewed in the first colour.

US Pat. No. 9,248,637

SECURITY ELEMENTS AND METHODS AND APPARATUS FOR THEIR MANUFACTURE

DE LA RUE INTERNATIONAL L...

1. An apparatus for magnetically imprinting indicia into a layer on an article, the layer comprising a composition in which
magnetic or magnetisable particles are suspended, the apparatus comprising:
a soft magnetisable sheet, having an outer surface arranged to face the article in use, and an opposing interior surface;
and

a permanent magnet, shaped such that its magnetic field contains perturbations giving rise to indicia, the permanent magnet
being disposed adjacent the interior surface of the soft magnetisable sheet, a lateral periphery of the permanent magnet in
a plane perpendicular to the normal of the soft magnetisable sheet being within that of the soft magnetisable sheet;

whereby the soft magnetisable sheet enhances the perturbations of the magnetic field of the permanent magnet such that when
the layer to be imprinted is located adjacent the outer surface of the soft magnetisable sheet, the magnetic or magnetisable
particles are oriented by the magnetic field to display the indicia, and

wherein the permanent magnet is configured such that its lateral shape approximately corresponds to a lateral shape of an
indicia which the apparatus is adapted to imprint into the layer.

US Pat. No. 10,087,583

SECURITY ELEMENTS

De La Rue International L...

1. A security element comprising:at least one light transmitting carrier substrate;
a first metal layer having substantially metal-free areas defining a first set of indicia having a defined shape which are visible in transmitted light; and
a partial first light scattering layer forming a second set of indicia having a defined shape which are visible in reflected light, the defined shape of the indicia of the first set being different from the defined shape of the indicia of the second set, wherein the first light scattering layer overlaps the substantially metal free areas in the first metal layer.

US Pat. No. 9,802,437

SECURITY DEVICE AND METHOD OF MANUFACTURE

DE LA RUE INTERNATIONAL L...

1. A security device comprising:
an array of focusing elements, the focusing elements being arranged on a regular two-dimensional grid extending in two orthogonal
directions, each focusing element being adapted to focus light in the two orthogonal directions; and

an array of elongate image elements overlapping the array of focusing elements, configured such that each focusing element
can direct light from any one of a respective set of at least two elongate image elements to the viewer, in dependence on
the viewing angle;

wherein in a first region of the security device, the elongate image elements extend along a first direction, and in a second
region of the security device, the elongate image elements extend along a second direction which is different to the first
direction.

US Pat. No. 9,508,840

DIODE, USE THEREOF, AND A METHOD FOR PRODUCING THE SAME

ACREO SWEDICH ICT AB, Ki...

1. A diode comprising:
a first conductor and a second conductor;
a semiconducting layer comprising semiconducting material at least partly embedded in an inert matrix, which semiconducting
layer is arranged between said first conductor and said second conductor, and

a conducting layer comprising conducting material at least partly embedded in an inert matrix, which conducting layer is arranged
between said semiconducting layer and said second conductor;

wherein:
said layers are stacked on top of each other in a first direction; and
the interface between said first conductor and said semiconducting layer provides a rectifying junction;
the interface between said conducting layer and said semiconducting layer provides a first junction; and
the interface between said second conductor and said conducting layer provides a second junction,
wherein the rectifying junction in operation provides a higher resistance under reversed bias, compared to the total resistance
of the rectifying junction and the first and second junctions under forward bias.

US Pat. No. 9,411,074

SECURITY DEVICE

DE LA RUE INTERNATIONAL L...

1. A security device comprising:
a region of piezochromic material;
a first discrete absorbing region;
a second discrete absorbing region; and
an integrated relief structure that includes structural modulations, wherein
when the region of piezochromic material and the integrated relief structure are together subjected to a stress, an optical
effect is generated in the region of piezochromic material by the stress causing localized modulations in the deformation
of the piezochromic material, which are representative of the structural modulations of the integrated relief structure, such
that the optical effect generated is representative of the structural modulations of the relief of the integrated relief structure;

at least one of the first discrete absorbing region and the second discrete absorbing region comprises the integrated relief
structure; and

the structural modulations are modulations of the at least one of the first discrete absorbing region and the second discrete
absorbing region.

US Pat. No. 9,724,955

SECURITY DEVICES AND METHODS OF MANUFACTURE THEREOF

DE LA RUE INTERNATIONAL L...

1. A security device comprising:
a first transparent layer having an optically variable effect generating relief structure formed in a surface thereof;
a reflection enhancing layer extending over the relief structure, both surfaces of the reflection enhancing layer following
the contour of the relief structure such that the optically variable effect is exhibited on both sides; and

a second transparent layer extending over the reflection enhancing layer, a lateral extent of the second transparent layer
being less than a whole area of the security device and corresponding to a lateral extent of the reflection enhancing layer,

wherein the first and/or second transparent layer comprises one or more optically effective substances such that the appearance
of the optically variable effect generated by the relief structure is different when viewed through the first transparent
layer compared with when viewed through the second transparent layer, at least under illumination at a wavelength at which
at least one of the optically effective substance(s) is visible; and

wherein the lateral extent of the reflection enhancing layer and second transparent layer does not match a lateral extent
of the relief structure.

US Pat. No. 9,739,014

ELECTROTYPE FOR FORMING AN IMAGE DURING A PAPER MAKING PROCESS

DE LA RUE INTERNATIONAL L...

1. An attachment to a face cloth of a cylinder mould for forming an image during a paper making process, the attachment comprising:
an electrotype having a mesh; and
at least one image forming element attached to the mesh.

US Pat. No. 9,156,302

SUBSTRATES INCORPORATING SECURITY DEVICES

De La Rue International L...

1. A security substrate comprising at least one elongate security device, which security device has a series of first regions
exposed at a series of windows formed in at least a first surface of the substrate and a series of second regions covered
by the substrate at bridges formed between the windows in the first surface of the substrate, wherein each of the first regions
comprises a first security feature which has substantially the same appearance in each region and is visible in each window
when the first surface of the substrate is viewed in reflected light and the second regions comprise a second security feature
which has substantially the same appearance in each second region but is different from the first security feature and is
not visible when the first surface of the substrate is viewed in reflected light, but is visible when the first surface of
the substrate is viewed in transmitted light, in which the security device is substantially wholly exposed at a second surface
of the substrate.

US Pat. No. 9,902,187

SECURITY DEVICES AND METHODS OF MANUFACTURE THEREOF

DE LA RUE INTERNATIONAL L...

1. A security device comprising a transparent layer having a first optically variable effect generating relief structure formed
in a surface thereof; a reflection enhancing body extending over the first relief structure and following the contour of the
first relief on a first side of the reflection enhancing body; and a second optically variable effect generating relief structure
formed in a second side of the reflection enhancing body, the reflection enhancing body comprising at least a first reflection
enhancing layer defining the first and/or second sides of the reflection enhancing body, the first reflection enhancing layer
comprising a binder having reflective particles dispersed therein, wherein when the device is viewed through the transparent
layer, the optically variable effect of the first relief structure is visible and when the device is viewed from the other
side, the optically variable effect of the second relief structure is visible.
US Pat. No. 9,804,497

SECURITY DEVICES AND METHODS OF MANUFACTURE THEREOF

DE LA RUE INTERNATIONAL L...

1. A method of manufacturing at least part of a security device, the method comprising:
conveying a substrate web comprising a photosensitive film along a transport path, the photosensitive film being adapted to
exhibit an increase in optical density upon exposure to radiation of a predetermined wavelength and concurrent or subsequent
heating, the increase in optical density being due to the formation of bubbles within the photosensitive film;

exposing the photosensitive film to radiation of the predetermined wavelength through a mask, wherein the mask comprises a
predetermined pattern of regions which are substantially opaque to radiation of the predetermined wavelength and at least
semi-transparent to radiation of the predetermined wavelength, respectively;

during the exposure, moving the mask alongside the substrate web along at least a portion of the transport path at substantially
the same speed as the substrate web, such that there is substantially no relative movement between the mask and the substrate
web; and

heating the substrate web comprising the exposed photosensitive film;
whereby regions of the photosensitive film exposed to the radiation of the predetermined wavelength undergo an increase in
optical density such that the photosensitive film displays a reproduction of the predetermined pattern.

US Pat. No. 9,776,444

SECURITY DEVICE

DE LA RUE INTERNATIONAL L...

1. A security device comprising:
a first array of first and second pluralities of lines on a substrate, the first and second pluralities of lines comprising
respectively different materials that have the same visible appearance with respect to colour under visible light illumination,
the material(s) of the first plurality of lines or portions of the first plurality of lines comprising luminescent and/or
photochromic pigments such that the first plurality of lines or portions of the first plurality of lines appear visibly different
in colour to the second plurality of lines under a combination of visible light and ultraviolet illumination; and

a second array of lines imposed on the first array, the orientation, line widths and spacings of the first and second arrays
being such that the device exhibits a variable, visible appearance with respect to colour as it is tilted while exposed to
the combination of visible and ultraviolet illumination.

US Pat. No. 9,649,871

SECURITY ELEMENTS, AND METHODS AND APPARATUS FOR THEIR MANUFACTURE

DE LA RUE INTERNATIONAL L...

1. A security element comprising a layer disposed on a substrate, the layer comprising a composition having magnetic or magnetisable
particles therein, each particle having at least one substantially planar surface,
wherein the magnetic or magnetisable particles vary in orientation across the layer such that:
at a first part of the layer, the particles are orientated with their planar surfaces substantially parallel to the normal
to the layer, the angle between the planar surfaces of the particles and the normal gradually increasing with increasing distance
from the first part to a maximum of approximately 90 degrees at a first position of the layer before decreasing gradually
again until a second, father, position of the layer, the normals to the planar surfaces of the particles disposed between
the first part and the second position intersecting one another at points on a first side of the layer, and

from the second position, the angle between the planar surfaces of the particles and the normal of the layer gradually increases
with increasing distance, the normals to the planar surfaces of the particles intersecting one another at points on a second
side of the layer, opposite to the first side,

such that the security element displays a bright edge corresponding to the first position, between a first dark area which
includes the first part of the layer, and a second dark area, at least when the security element is viewed along a direction
substantially normal to the plane of the substrate, and

wherein when viewed under daylight, the thickness of the bright edge between the contrasting dark areas is less than about
10 mm.

US Pat. No. 9,731,539

SECURITY DEVICES

DE LA RUE INTERNATIONAL L...

1. A security device, comprising:
an at least semi-transparent layer exhibiting a first pattern of integral regions having a raised surface profile relative
to intervening regions of the layer, the first pattern comprising raised regions each having at least two flank surfaces that
are non-parallel to a plane of the device, and the material of the raised regions being of high optical density relative to
the material of the intervening regions of the layer; and

a colour layer arranged to follow the contours of the integral regions and exhibiting a second pattern comprising elements
of at least two different colours, the second pattern being configured such that (i) at least two of the flank surfaces of
each raised region exhibit different colour appearances and (ii) at least elements of the second pattern corresponding to
the intervening regions of the first pattern are semi-transparent;

wherein the first and second patterns at least partially overlap one another and are configured such that:
when the device is viewed in reflected light from at least a first side of the device, the first and second patterns co-operate
to generate an optically variable effect whereby the appearance of the device changes between a first colour and second colour
at different viewing angles; and

when the device is viewed on-axis in transmitted light, a colour is exhibited that is different from the colour exhibited
by the device when viewed on-axis in reflected light from the first side of the device.

US Pat. No. 9,573,407

SECURITY SUBSTRATES

De La Rue International L...

1. A security substrate, said substrate comprising:
an at least partially light transmitting carrier supporting a security feature, said security feature comprising a first and
a second layer and a metallic and a demetallised region at least partially superimposed with the first and second layers,
at least one of said first and second layers covering an area which is less than a full surface area of the carrier and which
at least partially overlaps the other layer, wherein the first and second layers have substantially the same colour and texture,
and the reflective contrast ratio (expressed as a percentage) of the overlapping areas and the non-overlapping areas is less
than 20% and the transmissive contrast ratio (expressed as a percentage) of the overlapping areas and the non-overlapping
areas is greater than 3%, the contrast ratios of each of the areas defined by the first and second layers being selected in
combination with one another such that;

when the security substrate is viewed in reflected light, the first and second layers are indiscernible from each other and
have the appearance of a single homogenous area; and

when the substrate is viewed in transmitted light, the first and second layers are clearly distinguishable from each other.

US Pat. No. 9,563,999

METHOD AND SYSTEM FOR IDENTIFYING A SECURITY DOCUMENT

DE LA RUE INTERNATIONAL L...

1. A method of identifying a security document using an identifying device provided with a capacitance sensor and a second
sensor, the second sensor being an imaging sensor, the method comprising:
a) capacitively coupling a first element of the security document with the capacitance sensor;
b) obtaining first data from the first element using the capacitance sensor;
c) obtaining second data in the form of image data from the security document using the second sensor;
d) analyzing whether the first data and second data are related by a predetermined relationship; and
e) generating output data based upon the analyzing of the first and second data.

US Pat. No. 10,022,999

SECURITY DEVICE

DE LA RUE INTERNATIONAL L...

1. A security device comprising a substrate carrying a surface relief optically variable effect generating structure formed by a super position of three diffractive image generating structures such that each of the three diffractive image generating structures fully overlap one another and the three diffractive image generating structures each respond to respectively different colour components or wavelength ranges of white light to generate together a first, substantially achromatic image or background pattern located in a plane spaced from a surface of the substrate.

US Pat. No. 9,902,186

SECURITY DEVICES

DE LA RUE INTERNATIONAL L...

1. A security device comprising
a first pattern of elements and
a second, overlapping, pattern of elements spaced by a transparent layer, the first and second patterns in combination obstructing
the passage of light transmitted to a viewer through the device to a varying degree depending on the viewing position, wherein

the first and second patterns of elements are configured so as to define at least three regions of the device, constituting
a first group of regions, each region exhibiting a maximum degree of obstruction when observed by a viewer from at least one
maxima viewing position, and a minimum degree of obstruction when observed by a viewer from at least one minima viewing position,
the at least one maxima viewing position and the at least one minima viewing position constituting a set of peak viewing positions
for each region,

the sets of peak viewing positions associated with each of the regions of the first group respectively are different from
one another,

at least when viewed from a position away from the normal, each of the at least three regions of the first group exhibits
a different degree of obstruction, and

the lateral offset of the first pattern relative to the second pattern is different in each of the at least three regions
of the first group, whereby when viewed from the normal viewing position, contrast is exhibited between each of the regions
of the first group and when the tilt angle is changed relative to the viewer along at least one tilt direction, the contrast
exhibited between each of the regions of the first group changes.

US Pat. No. 10,127,755

MOIRE MAGNIFICATION DEVICE

DE LA RUE INTERNATIONAL L...

1. A moiré magnification device comprising a transparent substrate carrying:i) a periodic array of micro-focusing elements on a first surface, the micro-focusing elements defining a focal plane;
ii) a first array of microimages in an ink of a first color and located in a plane coincident with the focal plane of the micro-focusing elements; and
iii) a second array of microimages, in an ink of a second color different from the first color, and located in a plane coincident with the focal plane of the micro-focusing elements, the second array of microimages being laterally offset from the first,
wherein pitches of the micro-focusing elements and first and second arrays of microimages and their relative locations are such that the array of micro-focusing elements cooperates with each of the first and second arrays of microimages to generate respective magnified versions of the microimages of each array due to a moiré effect,
and such that when viewing the arrays of microimages simultaneously, an interruption zone of non-zero width is perceived between the magnified version of the first microimage array and the magnified version of the second microimage array, the interruption zone exhibiting no magnified version of either microimage array,
wherein the first array of microimages is laterally spaced from the second array of microimages by a boundary region of non-zero width which is free of microimages, thereby giving rise to the perceived interruption zone, and
wherein the width of the microimage element-free boundary region is greater than a maximum pitch of either of the microimage element arrays.

US Pat. No. 10,249,113

SECURE ENTRY SYSTEM

DE LA RUE INTERNATIONAL L...

1. A secure entry system comprising:an authorization apparatus including a reader for reading data, the reader including a transparent record medium presenting region and a border region extending alongside the transparent record medium presenting region; and
a record medium; wherein
the record medium is configured to be presented to the reader,
the reader and the record medium or a member connected to the record medium include at least two pairs of visible markings,
the reader includes a first member of each of the pairs of markings, the first member of each of the pairs of markings being located in the border region of the reader, and the record medium or the member connected to the record member includes a second member of each of the pairs of markings, the first and second members of each pair cooperating together in a predetermined manner only when the record medium is correctly presented to the reader, and
cooperation between the two pairs of visible markings is visible to a person presenting the record medium to the reader by placing the record medium face down onto the transparent record medium presenting region as the markings of each pair being disposed side by side and the first member of each of the pairs of markings being alongside a respective different lateral edge of the record medium when the record medium is correctly presented to the reader.

US Pat. No. 10,112,432

SECURITY DEVICE

DE LA RUE INTERNATIONAL L...

1. A security device comprising:a first transparent coloured element disposed in a first region of the device, the first transparent coloured element defining a first surface;
a second transparent colored element disposed in the first region of the device and being adjacent to the first transparent coloured element, the second transparent coloured element defining a second surface;
a first optically variable effect generating relief microstructure extending across the first surface of the first transparent coloured element and the second surface of the second transparent coloured element;
a third transparent coloured element disposed in a second region of the device, the second region being laterally offset and spaced apart from the first region, the third transparent coloured element defining a third surface;
a second optically variable effect generating relief microstructure extending across the third surface of the third transparent coloured element; and
a reflection enhancing layer extending: (i) across the first optically variable effect generating relief microstructure and following a first contour of the first optically variable effect generating relief microstructure, and (ii) across the second optically variable effect generating relief microstructure and following a second contour of the second optically variable effect generating relief microstructure, wherein
the reflection enhancing layer extending across the first and second optically variable effect generating relief structures are formed of an identical material, and
the reflection enhancing layer is provided in discrete portions in the first region and second region respectively.

US Pat. No. 10,093,124

SECURITY DEVICES AND METHODS OF MANUFACTURE

DE LA RUE INTERNATIONAL L...

1. A security device, comprising:an array of focusing elements, each focusing element being adapted to focus light in at least a first direction, the focusing elements being arranged on a regular grid in at least one dimension; and
an array of image elements overlapping the array of focusing elements, the image elements being arranged based on a repeating unit cell defining image element positions, the periodicity of the unit cells being substantially the same as that of the grid on which the array of focusing elements is arranged, the unit cell defining a set of image element positions therewithin, each image element position within the unit cell being assigned to carry an image element of a respective corresponding image;
whereby, depending on the viewing angle, the array of focusing elements directs light from selected image element positions to the viewer, such that as the device is tilted different ones of the respective images are displayed by the image elements at the selected image element positions in combination, sequentially;
wherein a center area of each unit cell, comprising one or more image element positions, is provided with one or more image elements of a corresponding center image, the center area being larger than each outer area of the unit cell, the outer areas being located outside the center area and provided with image elements of other respective images defined by the array of image elements, such that a first range of viewing angles, over which the center image is displayed to a viewer, is greater than a range of viewing angles over which each other image is displayed, and wherein an appearance of the security device remains static over the first range of viewing angles.

US Pat. No. 10,252,562

SECURITY ELEMENTS AND METHODS OF THEIR MANUFACTURE

DE LA RUE INTERNATIONAL L...

1. A security element comprising a substrate on which is disposed:in a first area, a first optically variable device comprising a diffractive or reflective relief structure and a reflection enhancing material following contours of the relief structure; and
in a second area, a second optically variable device comprising an iridescent amplitude interference material;
wherein the first optically variable device is constituted by a plurality of sub-areas arranged in a cyclically repeating sequence along a predetermined direction of the security element, the plurality of sub-areas collectively forming the first area, relief parameters of the diffractive or reflective relief structure varying from one sub-area to the next within each repeat cycle, wherein each repeat cycle of the relief parameters includes at least three sub-areas, and whereby, at any one viewing angle, each sub-area within any one repeat cycle exhibits a different diffractive colour or reflected intensity from those of the other sub-areas within the same repeat cycle, and such that, when the device is tilted in a direction parallel to the predetermined direction, different diffractive colours or reflected intensities appear to move from one sub-area to the next within each repeat cycle along the predetermined direction.