U.S. patent application number 14/431502 was filed with the patent office on 2017-02-02 for light control film formed with a security feature.
The applicant listed for this patent is ENTRUST DATACARD CORPORATION. Invention is credited to Ulrich Bielesch.
Application Number | 20170028761 14/431502 |
Document ID | / |
Family ID | 50235097 |
Filed Date | 2017-02-02 |
United States Patent
Application |
20170028761 |
Kind Code |
A9 |
Bielesch; Ulrich |
February 2, 2017 |
LIGHT CONTROL FILM FORMED WITH A SECURITY FEATURE
Abstract
A light control film is described that is formed with at least
one security feature therein. The security feature is not visible
when the film is viewed at an incorrect angle. The security feature
only becomes visible when the film is viewed at the correct viewing
angle or range of viewing angles. A plurality of security features
can be formed in the film at substantially the same location(s),
but at different angles, so that each security feature only becomes
visible when the film is viewed at the correct respective viewing
angle or range of viewing angles. The light control film can be
integrated into any type of document where resistance to
counterfeiting and fraudulent alteration are important, such as
plastic identification or credit cards, or passports.
Inventors: |
Bielesch; Ulrich; (Frucht,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ENTRUST DATACARD CORPORATION |
Shakopee |
MN |
US |
|
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20150246571 A1 |
September 3, 2015 |
|
|
Family ID: |
50235097 |
Appl. No.: |
14/431502 |
Filed: |
February 1, 2013 |
PCT Filed: |
February 1, 2013 |
PCT NO: |
PCT/US2013/024329 PCKC 00 |
371 Date: |
March 26, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B42D 25/41 20141001;
B42D 25/23 20141001; B42D 25/30 20141001; G02B 27/46 20130101; B42D
25/435 20141001; B42D 25/309 20141001; B42D 25/29 20141001; B41M
3/148 20130101; G02B 5/0231 20130101; G02B 2207/123 20130101; B42D
2035/36 20130101; G02B 5/1842 20130101; B23K 2203/50 20151001; B42D
25/40 20141001; G02B 5/003 20130101; B42D 25/24 20141001; B42D
25/00 20141001; G02B 17/006 20130101; B42D 25/36 20141001 |
International
Class: |
B42D 25/30 20060101
B42D025/30; B42D 25/40 20060101 B42D025/40; B23K 26/40 20060101
B23K026/40; B23K 26/08 20060101 B23K026/08; G02B 5/02 20060101
G02B005/02; B23K 26/36 20060101 B23K026/36 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 26, 2012 |
DE |
10 20121 090 64.5 |
Claims
1. A light control film having a plurality of micro light control
structures formed in the film, and a first security feature formed
in the micro light control structures, wherein the light control
film is generally transparent or translucent at a primary viewing
angle, the first security feature is not visible when the light
control film is viewed at a first viewing angle, and the first
security feature is visible when the light control film is viewed
at a correct viewing angle or range of viewing angles.
2. The light control film of claim 1, further comprising a second
security feature formed in the micro light control structures
located in generally the same area and/or adjacent to the first
security feature, wherein the film is generally transparent or
translucent at the primary viewing angle, the second security
feature is not visible when the light control film is viewed at the
first viewing angle, and the second security feature is visible
when the light control film is viewed at a correct viewing angle or
range of viewing angles, the correct viewing angle or range of
viewing angles at which the second security feature is visible is
different than or the same as the correct viewing angle or range of
viewing angles at which the first security feature is visible.
3. The light control film of claim 2, wherein the first security
feature is formed in the micro light control structures at an angle
that is different than the first viewing angle, and wherein the
second security feature is formed in the micro light control
structures at an angle that is different than the first viewing
angle.
4. The light control film of claim 1, wherein the plurality of
micro light control structures: are parallel to each other, are
inclined to a vertical axis, or intersect one another.
5. A method of creating a security feature in a light control film
having a plurality of micro light control structures formed in the
film, the light control film being generally transparent or
translucent when the light control film is viewed at a primary
viewing angle, comprising: using a laser beam to destroy portions
of the micro light control structures to form a first security
feature; wherein the light control film remains generally
transparent or translucent at the primary viewing angle, the first
security feature is not visible when the light control film is
viewed at the first viewing angle, and the first security feature
is visible when the light control film is viewed at a correct
viewing angle or range of viewing angles.
6. The method of claim 5, further comprising using a laser beam to
destroy portions of the micro light control structures to form a
second security feature located in the same area and/or adjacent to
the first security feature, wherein the light control film remains
generally transparent or translucent at the primary viewing angle,
the second security feature is not visible when the light control
film is viewed at the first viewing angle, and the second security
feature is visible when the light control film is viewed at a
correct viewing angle or range of viewing angles, the correct
viewing angle or range of viewing angles at which the second
security feature is visible is different than or the same as the
correct viewing angle or range of viewing angles at which the first
security feature is visible.
7. The method of claim 6, wherein the laser beam contacts the micro
light control structures destroyed thereby at an angle that is
different than the first viewing angle, and wherein the laser beam
that forms the second security feature contacts the micro light
control structures destroyed thereby at an angle that is different
than the first viewing angle.
8. The method of claim 5, further comprising orienting the light
control film and the laser at a first relative position to one
another and forming the first security feature, and thereafter
moving the light control film and laser relative to one another to
a second relative position to one another and forming a second
security feature.
9. The method of claim 8, wherein moving the light control film and
the laser relative to one another to the second relative position
comprises tilting the light control film and the laser relative to
one another from the first relative position to the second relative
position or rotating the light control film and the laser relative
to one another from the first relative position to the second
relative position about an axis vertical to a plane of the light
control film.
10. The method of claim 5, wherein the first security feature
comprises a portrait image, text data, or a logo, and the second
security feature comprises a portrait image, text data, or a
logo.
11. A document that includes a light control film, the light
control film having a plurality of micro light control structures
formed in the film, and a first security feature formed in the
micro light control structures, the first security feature is not
visible when the document and the light control film are viewed at
a first viewing angle, and the first security feature is visible
when the document and the light control film are viewed at a
correct viewing angle or range of viewing angles.
12. The document of claim 11, further comprising a second security
feature formed in the micro light control structures located in
generally the same area and/or adjacent to the first security
feature, the second security feature is not visible when the light
control film is viewed at the first viewing angle, and the second
security feature is visible when the light control film is viewed
at a correct viewing angle or range of viewing angles.
13. The document of claim 11, wherein the document is a plastic
card or a passport.
14. The document of claim 13, wherein the document includes a first
generally transparent or translucent layer overlying a first side
of the light control film, and a generally transparent or
translucent layer overlying a second side of the light control
film.
15. The document of claim 13, wherein the document includes a first
generally transparent or translucent layer overlying a first side
of the light control film, and a nontransparent/nontranslucent
layer overlying a second side of the light control film.
16. The document of claim 13, wherein the first security feature
comprises a portrait image, text data, or a logo, and the second
security feature comprises a portrait image, text data, or a logo.
Description
FIELD
[0001] This disclosure relates to a light control film, also known
as a light collimating film or a visual protection foil, formed
with at least one security feature, and to an identification
document that includes such a light control film.
BACKGROUND
[0002] The construction and operation of light control films, also
known as light collimating films or visual protection foils, is
well known. Light control films are used to regulate the
directionality of transmitted light. For example, see WO2010/090924
and US2010/0201242. These films have a plurality of parallel
grooves or light control structures, which are formed of
alternating structures of light absorbing material and light
transmitting material, so that depending on the orientation of the
grooves, the pitch and the geometry, the films provide a maximum
light transmission at a predefined angle and an image cut off or
black out for angles different from the predefined angle. When the
film is viewed at a first viewing angle, light is transmitted
through the film allowing one to see substantially unobstructed
through the film so that the film appears to be substantially
transparent. However, when the film is viewed at a second viewing
angle, light is blocked and the film appears dark, thereby
preventing seeing through the film.
[0003] Identification documents such as identification cards,
credit and debit cards, driver's licenses, and the like, and
passports, are personalized with information concerning the
intended holder of the identification document and then issued to
the intended holder. Personalization and issuance are typically
handled by government agencies, credit card companies, or other
entities authorized to handle the personalization and issuance
process.
[0004] As part of the personalization and issuance process, the
identification documents can undergo a number of personalization
procedures, including printing, portrait printing, magnetic stripe
and/or chip encoding, embossing, lamination of protective
laminates, and other known procedures.
[0005] A number of security measures have been implemented in order
to resist counterfeiting, forgery or tampering with identification
documents.
[0006] One technique uses laser engraving because of the advantage
that the information can be written inside the document layers
using the laser, so that the information cannot be removed,
modified, or replaced from the surface like printing. With laser
engraving, the document must consist of appropriate material, which
reacts in the designated way to the laser.
[0007] In order to avoid copying and direct printing, one known
security feature uses a lens structure on the top surface, and the
laser beam transmits through the lens structure and engraves the
layer underneath so that several different images can be placed at
the same area visible under different angles. This approach is
described in U.S. Pat. No. 4765656, U.S. Pat. No. 4892336, and WO
2006/137738. Following this approach, several images can be
engraved underneath the lens structure, which join together to form
one image with a three dimensional appearance, as disclosed in WO
2006/110038 and WO 2011/122943.
[0008] Another security feature as described in U.S. Pat. No.
6,786,513 is visible from both sides of the document so that a
falsification by modifying the surface can easily be detected. The
feature uses a laser to form micro holes with different sizes into
the document. The generated perforation pattern is visible when
viewed against a bright background. This feature involves the
complete thickness of the document including all layers. The
drilled holes perforate the surface of the document so that the
document gets susceptible to soiling. In addition, conventional
drilling machines with needle sized drilling bits may be able to
imitate the feature.
[0009] An example of a previous security feature that is ablated
into a foil is disclosed in U.S. Patent Application Publication US
2011/0037247.
[0010] Further improvements to security measures to resist
counterfeiting, forgery or tampering with identification documents,
as well as resist fraudulent use of identification documents once
issued, are needed.
SUMMARY
[0011] A light control film is described that is formed with at
least one security feature therein. The security feature is not
visible when the film is viewed at an incorrect angle. The security
feature only becomes visible when the film is viewed at the correct
viewing angle or range of viewing angles.
[0012] A plurality of security features can be formed in the film
at substantially the same location(s), but at different angles from
one another, so that each security feature only becomes visible
when the film is viewed at the correct viewing angle(s) generally
corresponding to the angle at which the respective security feature
was formed. The film otherwise appears generally transparent or
translucent when the film is viewed at a primary viewing angle or
dark when viewed at an incorrect viewing angle.
[0013] In one embodiment, the light control film can be integrated
into any type of document where resistance to counterfeiting and
fraudulent alteration are important. Examples of documents that can
employ the light control film described herein include, but are not
limited to, identification documents such as cards or passports,
security documents, stock certificates, property titles, and paper
currency. Specific examples of cards include, but are not limited
to, national or state identification cards, driver's licenses,
health care identification cards, and credit or debit cards.
[0014] A laser that is deployed at a particular angle to the film
is used to locally destroy micro light control structures within
the film to create the security feature. The resulting security
feature is visible only when the film is viewed at the correct
viewing angle or range of viewing angles. The laser created
security feature appears bright against a dark background of the
circumjacent film when the film with the security feature is tilted
to the appropriate angle. To create a second security feature, the
laser can be deployed at a second angle to the film. The resulting
second security feature is visible only when the film is viewed at
a correct viewing angle or range of angles.
[0015] The security feature(s) can be any feature(s) that is
provided to resist counterfeiting and fraudulent alteration of the
film or any document into which the film is incorporated. In one
embodiment, the security feature can be personal to a person, such
as some portion or all of the person's image, name, birth date,
social security number, a signature, an address, an assigned
account number, any other personal data of the person, and any
combination thereof. In another embodiment, the security feature is
not personal to a person, but is instead a static feature that is
used on multiple films. One example of a static security feature
includes, but is not limited to, a corporate logo or corporate
name. In another embodiment, the security feature is variable but
based on non-personal information, such as the date of creation of
the security feature in the film. The film can include any number
of, and combinations of, these types of security features, as well
as other features produced via a laser.
[0016] In one embodiment, a light control film having a plurality
of micro light control structures formed in the film is provided,
and a first security feature is formed in the micro light control
structures. The light control film is generally transparent or
translucent at a primary viewing angle, the first security feature
is not visible when the light control film is viewed at a first
viewing angle, and the first security feature is visible when the
light control film is viewed at a correct viewing angle or range of
viewing angles.
[0017] In another embodiment, the first security feature is formed
in the micro light control structures at an angle that is different
than the first viewing angle, and the correct viewing angle or
range of viewing angles is approximately equal to the angle at
which the first security feature is formed in the micro light
control structures.
[0018] In another embodiment, a second security feature is formed
in the micro light control structures located generally in the same
area and/or adjacent to the first security feature, wherein the
film is generally transparent or translucent at a primary viewing
angle, and the second security feature is not visible when the
light control film is viewed at the first viewing angle, and the
second security feature is visible when the light control film is
viewed at a correct viewing angle or range of viewing angles. The
correct viewing angle or range of viewing angles for viewing the
second security feature can be different than or the same as the
correct viewing angle or range of viewing angles for viewing the
first security feature.
[0019] In another embodiment, the second security feature is formed
in the micro light control structures at an angle, and wherein the
correct viewing angle or range of viewing angles for viewing the
second security feature is approximately equal to the angle at
which the second security feature is formed in the micro light
control structures.
[0020] In an embodiment, the correct viewing angle or range of
viewing angles is accomplished by rotating the light control film
around an axis perpendicular to the surface of the light control
film.
[0021] In another embodiment the first security feature is formed
in the micro light control structures at an angle that is different
than the first viewing angle, wherein the light control film is
generally transparent or translucent at a primary viewing angle and
the first security feature is not visible when the light control
film is viewed at a first viewing angle. The security feature is
visible in front of a dark background with illumination of the rear
side under an appropriate viewing angle or range of viewing angles.
The laser created security feature appears bright against a dark
background caused by light scattering of the illumination at the
position where the laser beam that forms the first security feature
contacts the micro light control structures destroyed thereby.
[0022] In another embodiment a second security feature is formed in
the micro light control structures located in the same area and/or
adjacent to the first security feature, wherein the film is
generally transparent or translucent at the primary viewing angle,
the second security feature is not visible when the light control
film is viewed at the first viewing angle, and the second security
feature is visible when the light control film is viewed in front
of a dark background with illumination of the rear side by rotating
the light control film around an axis perpendicular to the surface
under a similar viewing angle or range of viewing angles at which
the first security feature is visible. The second laser created
security feature appears bright against a dark background caused by
light scattering of the illumination at the position where the
laser beam that forms the second security feature contacts the
micro light control structures destroyed thereby.
[0023] In another embodiment, a document that includes the light
control film of the proceeding paragraphs is provided.
[0024] In one embodiment, the document can be a plastic card or a
passport.
[0025] In one embodiment, the document includes a first generally
transparent or translucent layer overlying a first side of the
light control film, and a generally transparent or translucent
layer overlying a second side of the light control film.
[0026] In one embodiment, the document includes a first generally
transparent or translucent layer overlying a first side of the
light control film, and a nontransparent/nontranslucent reflecting
or white layer overlying a second side of the light control
film.
[0027] In another embodiment, the first security feature comprises
a portrait image, text data, or a logo.
[0028] In another embodiment, a method of creating a security
feature in a light control film having a plurality of micro light
control structures formed in the film is provided. The light
control film is generally transparent or translucent when the light
control film is viewed at a primary viewing angle. In the method, a
laser beam is used to destroy portions of the micro light control
structures to form a first security feature. The light control film
remains generally transparent or translucent at the primary viewing
angle, and the first security feature is not visible when the light
control film is viewed at a first viewing angle, and the first
security feature is visible when the light control film is viewed
at a correct viewing angle or range of viewing angles.
[0029] In another embodiment of the method, the laser beam contacts
the micro light control structures destroyed thereby at an angle
that is different than the first viewing angle, and the correct
viewing angle or range of viewing angles is approximately equal to
the angle at which the laser beam contacts the micro light control
structures destroyed thereby.
[0030] In another embodiment of the method, a laser beam is used to
destroy portions of the micro light control structures to form a
second security feature located in generally the same area and/or
adjacent to the first security feature. The light control film
remains generally transparent or translucent at the primary viewing
angle, the second security feature is not visible when the light
control film is viewed at the first viewing angle, and the second
security feature is visible when the light control film is viewed
at a correct viewing angle or range of viewing angles. The correct
viewing angle or range of viewing angles for viewing the second
security feature can be the same as or different than the correct
viewing angle or range of viewing angles for viewing the first
security feature.
[0031] In another embodiment of the method, the laser beam that
forms the second security feature contacts the micro light control
structures destroyed thereby at an angle that is different than the
first viewing angle, and the correct viewing angle or range of
viewing angles for viewing the second security feature is
approximately equal to the angle at which the laser beam that forms
the second security feature contacts the micro light control
structures destroyed thereby.
[0032] In another embodiment of the method, the light control film
is incorporated in a document.
[0033] In an embodiment of the method, the document can be a
plastic card or a passport.
[0034] In an embodiment of the method, the first security feature
comprises a portrait image, text data, or a logo.
[0035] The security feature in the light control film is not
visible to standard photocopiers or scanners, thereby resisting
counterfeiting and fraudulent alteration based on photocopying and
scanning. Further, visible inspection of the security feature does
not require special tools or devices. No lens structure on the film
is required as is required for CLI/MLI technology. In addition, a
standard laser mechanism used to perform laser personalization on
documents can be used to produce the security feature in the
film.
DRAWINGS
[0036] FIG. 1 is a perspective view of one example of a light
control film.
[0037] FIG. 2 is a cross-sectional view of the light control film
of FIG. 1, with a security feature formed therein and incorporated
into an identification document.
[0038] FIG. 3 is a view of the light control film perpendicular to
the plane of the film with a pair of security features formed
therein.
[0039] FIG. 4 is a view of the light control film of FIG. 3 at a
correct viewing angle for viewing a first security feature formed
in the film.
[0040] FIG. 5 is a view of the light control film of FIG. 3 at a
correct viewing angle for viewing a second security feature formed
in the film.
[0041] FIG. 6 is a cross-sectional view of another embodiment of
the light control film incorporated into an identification
document.
[0042] FIG. 7 is a cross-sectional view of another embodiment of an
identification document that employs the light control film.
[0043] FIG. 8 is a perspective view of another embodiment of a
light control film that can be employed.
[0044] FIG. 9 is a perspective view of another embodiment of a
light control film that can be employed.
[0045] FIGS. 10a and 10b illustrate another embodiment of viewing
two security features formed at generally the same area in the
light control film.
[0046] FIG. 11 illustrates an embodiment that employs two layers of
light control film.
DETAILED DESCRIPTION
[0047] Referring initially to FIGS. 1 and 2, a light control film
10 is illustrated. The thickness of the film 10 has been greatly
exaggerated in FIGS. 1 and 2 in order to help explain the concepts.
The general construction and operation of a light control film,
also known as a visual protection foil, is well known in the art.
The film 10 is a generally planar structure with a plurality of
micro light control structures or walls 12. As used herein, the
term "micro" is intended to mean structures that are very small and
not visible to the naked eye. The structures can be, but are not
required to be, micron in size (one millionth (10.sup.-6) of a
meter). Examples of suitable light control films that can be used
include, but are not limited to, BSF33.8 Vikuiti.TM. available from
3M Corporation of St. Paul, Minn., USA or PS 14.1 WA2 available
from V7/Ingram Micro Inc. of Santa Ana, Calif., USA.
[0048] In the example illustrated in FIGS. 1 and 2, the structures
12 are linear structures that extend from one end of the film to
the opposite end parallel to one another in the y-direction and
extend the thickness of the film parallel to the z-direction. As
indicated in FIG. 2, when the typical film 10 is viewed along a
viewing direction or primary viewing angle 14 perpendicular to the
x-y plane of the film, the film appears to be generally transparent
or translucent. In addition, when the typical film is viewed along
a viewing direction 16 or viewing angle that is at an angle to the
x-y plane of the film, the film appears to be dark. This
construction and operation of the film 10 is conventional.
[0049] As depicted in FIG. 2, the film 10 is made to differ from
the conventional film in that a laser is used to create one or more
security features within the film. Each security feature is created
by using a laser beam 18 that can be deployed at a respective angle
a to the x-y plane of the film to locally change the
characteristics of the film 10 by locally destroying the structures
12 as indicated at the location 20 in FIG. 2.
[0050] When two or more security features are created, a first
security feature is created at an angle .alpha.1, a second security
feature is created at an angle .alpha.2 that is different than
.alpha.1, a third security feature is created at an angle .alpha.3
that is different than .alpha.1 and .alpha.2, etc. Each security
feature is visible when the film is viewed along a direction or
correct viewing angle 22 (or range of viewing angles discussed
further below) that is substantially equal to the angles .alpha.1,
.alpha.2, .alpha.3, etc. at which the laser was deployed.
[0051] In reality, each security feature can be visible over a
respective range of viewing angles .+-.a near .alpha.1, .alpha.2,
.alpha.3 depending upon the angle of incident light. So as used
herein, reference to a security feature being visible at a correct
viewing angle includes the security feature being visible at a
single, main viewing angle as well as being visible over a range of
viewing angles near the single, main viewing angle.
[0052] Therefore, a plurality of security features can be created
at generally the same or adjacent locations in the film 10 but at
different angles. This effect is demonstrated by referring to FIGS.
3-5. FIG. 3 illustrates the view through the film 10 that has been
modified to include a pair of security features at generally the
same location on the film using a laser as discussed above. In FIG.
3, the primary viewing angle is perpendicular to the x-y plane of
the film (i.e. along viewing direction 14 in FIG. 2) so that the
entire film appears to be generally transparent or translucent and
one can see through the film as with the standard film.
[0053] FIG. 4 shows the exact same film as in FIG. 3, but viewed at
a first correct viewing angle .alpha.1. When viewed at this angle,
a first security feature 26 in the form of a portrait image of a
person is visible. The first security feature 26 was formed using a
laser beam that was deployed at the angle .alpha.1 to locally
destroy the structures 12 in the film at locations to result in the
creation of the portrait image. The areas 28 of the film
surrounding the security feature 26 would appear to be dark since
the light control structures 12 in the areas 28 remain intact.
Although a single portrait image is illustrated and described, a
plurality of portrait images can be formed or other security
features can be formed with the security feature 26.
[0054] FIG. 5 shows the exact same film as in FIGS. 3 and 4, but
viewed at a second correct viewing angle .alpha.2 different than
the first correct viewing angle .alpha.1. When viewed at this
second correct viewing angle, a second security feature 40 in the
form of text data is visible. The second security feature 40 was
formed using a laser beam that was deployed at the second angle
.alpha.2 to locally destroy the structures 12 in the film at
generally the same locations on the film as the first security
feature 26. In the illustrated example, one block of text data is
illustrated and described corresponding to the portrait image 26 of
FIG. 4. However, multiple blocks of text data can be formed or
other security feature(s) can be formed as well. Also, the areas 42
of the film surrounding the second security feature 40 appear to be
dark since the light control structures 12 in the areas 42 remain
intact.
[0055] The first angle .alpha.1 and the second angle .alpha.2 for
creating and viewing the security features 26, 40 can be but are
not limited to, for example, between about 30 degrees to about 60
degrees respectively. However, larger and smaller angles are
possible.
[0056] The laser used to create the security feature(s) can be the
same type of laser as used in laser personalization processes on
cards and passports which are well known in the art. The security
feature(s) in the film 10 can be created in generally the same way
as laser personalization on cards and passports.
[0057] In case of a portrait image in the film 10, the laser
locally destroys the structures 12 to create regions of white. The
different levels of gray are realized by dithering (changing the
density of laser affected spots) of the laser generated image by
keeping the same laser power. In another embodiment, different
levels of gray in a portrait image in the film 10 can be achieved
by using equidistant raster of the laser affected spots but
adapting the power of the laser pulses respectively to the desired
level of gray.
[0058] The security features 26, 40 in FIGS. 4 and 5 are exemplary
only. In addition, at each angle a, a single security feature or a
plurality of security features can be employed. The security
feature(s) at each angle can be the same or different from each
other. In addition, in some embodiments, a security feature can be
provided at only one angle .alpha..
[0059] The security features can be personal to a person, such as
some portion or all of the person's image (see FIG. 4), name (see
FIG. 5), birth date, social security number, a signature, an
address, an assigned account number, any other personal data of the
person, and any combination thereof. In another embodiment, the
security feature is not personal to a person, but is instead a
static feature that is used on multiple films. One example of a
static security feature includes, but is not limited to, a
corporate logo or corporate name. In another embodiment, the
security feature is variable but based on non-personal information,
such as the date of creation of the security feature in the film.
The film can include any number and combinations of these types of
security features, as well as others, such as microtext engraving
which are laser engraved elements where magnification tools are
needed for discern the microtext letters or other characters.
[0060] With reference to FIG. 6, another embodiment of a light
control film 30 is illustrated. In this embodiment, the film 30
includes light control structures 32 that are inclined or angled to
the z-axis but are otherwise similar to the light control
structures 12. In this embodiment, when the film 30 is viewed along
a viewing direction or primary viewing angle 34 the film appears to
be generally transparent or translucent. In addition, when the film
30 is viewed along a viewing direction 36 or viewing angle that is
perpendicular to the x-y plane of the film, the film appears to be
dark.
[0061] However, in FIG. 6, a laser beam 38 is deployed to locally
change the characteristics of the structures 32 in the film 30 by
locally destroying the structures 32 as indicated at the location
41. The security feature is thus visible when the film is viewed
along a direction or correct viewing angle 43 that corresponds to
the angle at which the laser beam was deployed.
[0062] Other film constructions and laser beam deployment angles
can be used. For example, with reference to FIG. 8, a light control
film 50 is illustrated that includes light control structures 52a,
52b that extend in the x and y directions and that intersect each
other. A laser beam 58 is illustrated that is inclined at an angle
to both the x-direction (dx) and the y-direction (dy). A similar
beam inclination in the x and y directions could be used for the
laser beams 18, 38. Likewise, the light control film 50 could be
used with the embodiments described in FIGS. 1-6.
[0063] FIG. 9 illustrates an embodiment where two light control
films 60, 62 are stacked on top of one another. The light control
film 60 has light control structures 64 similar to the light
control structures 12 but extending in the x direction. The light
control film 62 has light control structures 66 similar to the
light control structures 12 that extend in the y direction. The
laser beam 68 can be inclined at an angle to both the x-direction
(dx) and the y-direction (dy), or the laser beam 68 can have no
(dy) component and extend solely in the x-direction. Likewise, the
stacked light control films 60, 62 could be used with the
embodiments described in FIGS. 1-6 and 8. This embodiment enables
the implementation of at least two security features, which are
visible at the appropriate viewing angle, switching the visibility
from one security feature to the other one by rotating the two
stacked and fixed light control films around the z axis by, for
example, 90 degrees.
[0064] The light control film with a security feature(s) created
therein can be integrated into a document where resistance to
counterfeiting and fraudulent alteration are important. Examples of
documents that can employ the light control films described herein
include, but are not limited to, identification documents such as
cards or passports, security documents, stock certificates,
property titles, and paper currency. Specific examples of cards
include, but are not limited to, national or state identification
cards, driver's licenses, health care identification cards, and
credit or debit cards.
[0065] FIG. 2 illustrates the light control film 10 incorporated
into an identification document 100 in the form of a plastic card,
such as a national or state identification card, a driver's
license, a health care identification card, or a credit or debit
card, or a page of a passport. In this example, the film 10 is
disposed between a pair of generally transparent or translucent
films (or topcoat layers) 102, 104 that overly each side of the
film 10 to protect the film 10. In this example, the films 102, 104
substantially cover the entire surfaces of the film 10.
[0066] The light control film tested by the inventor had a
generally transparent or translucent layer on each side. So even if
not incorporated into an identification document, the light control
film 10 can have a generally transparent or translucent layer on
both sides. However, a light control film without generally
transparent or translucent layers is conceivable, with customized
transparent or translucent layers being added on the bottom and top
of the film.
[0067] The film 10 can include one or more security features formed
therein as described above. For example, the film can include a
portrait image of the intended holder of the document 100 and/or
text data relating to the intended holder of the document created
therein at different angles .alpha.1 and .alpha.2 using a laser as
discussed above. The security feature(s) formed in the film 10 can
match security features formed on the films 102, 104, or on other
layers or structures of the document 100. For example, a portrait
image security feature formed in the film 10 can match a portrait
image of the intended document holder that is formed on the layer
102, the layer 104, or other layer or structure of the document
100.
[0068] In the example in FIG. 2, data can be provided on the inner
surface of the film 102 and/or on the inner surface of the film
104. Because both films 102, 104 are generally transparent or
translucent, the security feature(s) in the film 10 and other data
on the films 102, 104 are visible from both sides of the document
100.
[0069] Another example of an identification document 110 is
illustrated in FIG. 6 where the film 30 is disposed between a pair
of generally transparent or translucent films (or topcoat layers)
112, 114 that overly each side of the film 30 to protect the film
30.
[0070] FIG. 7 is a cross-sectional view of another embodiment of an
identification document 120 in the form of a plastic card, such as
a national or state identification card, a driver's license, a
health care identification card, or a credit or debit card, or a
page of a passport, into which the light control film 10 (or the
films 30, 50, 60) is integrated. In this example, the film 10 is in
the form of a patch that is smaller in size than the overlying
transparent or translucent films 122, 124.
[0071] The patch-size film 10 in FIG. 7 can include one or more
security features formed therein as described above. The use of a
patch-size film 10 means that any data on the films 122, 124 or
otherwise not underlying the film 10 will remain visible at all
viewing angles.
[0072] In another embodiment, the films 122 and 124 are only
transparent or translucent in the area over and/or underlying the
area of the light control film 10 and not transparent or
translucent in the remaining area.
[0073] In another embodiment, one of the films 122 and 124 is not
transparent or translucent in the area over or underlying the area
of the light control film 10. Therefore the security feature(s)
only becomes visible when the film 10 is viewed at the correct
viewing angle, from the one side having the film that is
transparent or translucent at the area of the light control film
10.
[0074] In all embodiments described herein, the portion of the
layer(s) underlying or overlaying the light control film does not
need to be transparent or translucent. Instead, the overlaying or
underlying layer can be opaque.
[0075] With reference to FIGS. 10a and 10b, another example of
viewing two security features formed at generally the same area in
a light control film (or transparent identification document) 150
is illustrated. The film 150 includes a first security feature 152
(FIG. 10a) and a second security feature 154 (FIG. 10b) formed
therein using a laser as described above. The film 150 is observed
in front of a dark background 156, while a light source 158
provides illumination generally on the back side or at an angle to
the back side of the film 150. The background 156 is spaced from
the film 150 so that there is a gap between the two.
[0076] The security feature 152 is visible when the light control
film 150 is viewed at the correct viewing angle(s) .alpha.1. The
film is then rotated about the axis A-A, for example 180 degrees,
to the position in FIG. 10b. Once the film is rotated, the security
feature 154 is visible when viewed at the correct viewing angle(s)
.alpha.2.
[0077] In the example illustrated in FIGS. 10a and 10b, the viewing
angle .alpha.1 equals the viewing angle .alpha.2. However, the
viewing angles .alpha.1 and .alpha.2 need not be the same. In
addition, although the film 150 has been described as being rotated
180 degrees, the film can be rotated other amounts greater or
lesser than 180 degrees. For example, if the film 150 is
constructed like that described in FIG. 9, the film would be
rotated 90 degrees.
[0078] FIG. 11 illustrates an embodiment where two light control
films 200, 202, similar to the film 30 shown in FIG. 6, are stacked
on top of each other. The film 200 has light control structures 204
arranged similarly to the light control structures 32 in the film
30 of FIG. 6, while the film 202 has light control structure 206
angled in the opposite direction. The result is a combined
structure where each individual light control film by itself is
generally transparent or translucent and includes one or more
security features as described herein, but the resulting combined
structure is not generally transparent or translucent because of
the arrangement of the light control structures in each film.
[0079] The embodiments disclosed in this application are to be
considered in all respects as illustrative and not limitative. The
scope of the claimed invention is indicated by any appended claims
rather than by the foregoing description, and all changes which
come within the meaning and range of equivalency of the claims are
intended to be embraced therein.
* * * * *