U.S. patent application number 10/814975 was filed with the patent office on 2004-12-23 for method of dry printing and painting.
Invention is credited to Faris, Sadeg, Jiang, Yingqiu, Li, Le.
Application Number | 20040258894 10/814975 |
Document ID | / |
Family ID | 22498087 |
Filed Date | 2004-12-23 |
United States Patent
Application |
20040258894 |
Kind Code |
A1 |
Jiang, Yingqiu ; et
al. |
December 23, 2004 |
Method of dry printing and painting
Abstract
A method of producing an iridescent reflecting surface on an
object is presented. Flakes of dry non metallic reflecting material
such as cholesteric liquid crystal (CLC) material are applied to
the surface so that the flakes are parallel with the surface and
bound with a binder to the surface.
Inventors: |
Jiang, Yingqiu; (Sunnyvale,
CA) ; Li, Le; (Yorktown Heights, NY) ; Faris,
Sadeg; (Pleasantville, NY) |
Correspondence
Address: |
REVEO, INC.
85 Executive Boulevard
Elmsford
NY
10523
US
|
Family ID: |
22498087 |
Appl. No.: |
10/814975 |
Filed: |
March 31, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10814975 |
Mar 31, 2004 |
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10357293 |
Feb 3, 2003 |
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10357293 |
Feb 3, 2003 |
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09141984 |
Aug 28, 1998 |
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6515717 |
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Current U.S.
Class: |
428/212 ;
427/180; 427/458 |
Current CPC
Class: |
G03G 9/0926 20130101;
Y10T 428/254 20150115; Y10T 428/232 20150115; Y10T 428/24942
20150115; B05D 1/06 20130101; B41M 3/14 20130101; B41M 3/148
20130101; B41M 3/00 20130101; G03G 9/0906 20130101; G02B 5/3016
20130101; Y10T 428/239 20150115; G03G 9/09 20130101 |
Class at
Publication: |
428/212 ;
427/458; 427/180 |
International
Class: |
B05D 001/12 |
Claims
1-54. (canceled)
55. A method of producing a pattern on a surface of a substrate,
the method comprising the steps of: (a) applying a patterned coat
of a binder material to the surface of a substrate; and (b)
applying a dry pigment material to the surface of the binder
material, the pigment material comprising flakes of a cholesteric
liquid crystal material, the pigment material adhering to the
binder material; wherein steps (a) and (b) are performed using a
printer selected from the group consisting of xerographic and laser
printers.
56. The method of claim 55 further comprising: repeating steps (a)
and (b) a plurality of times to build up a multipigmented
pattern.
57. The method of claim 55 wherein the binder material comprises a
fluid material.
58. The method of claim 55 wherein the binder material comprises a
fusible material.
59. The method of claim 55 wherein the binder material comprises a
radiation curable material.
60. The method of claim 55 wherein the binder material comprises a
mixture, the mixture comprising a non-volatile and a volatile
solvent.
61. The method of claim 55 further comprising the step of: (c)
mechanically working the surface of the binder to align the flakes
in a direction that is substantially parallel thereto.
62. The method of claim 61 wherein the step (c) comprises the step
of rolling the surface of the binder material.
63. The method of claim 61 wherein the step (c) comprises the step
of buffing the surface of the binder material.
64. The method of claim 55 wherein the flakes of cholesteric liquid
crystal material comprise a non-linear pitch distribution to
reflect a broad band of light.
65. The method of claim 55 further comprising the step of: (c)
applying a protective coating over the dry pigment material.
66. A method of producing a pattern on a surface of a substrate,
the method comprising the steps of: (a) applying a patterned coat
of a binder material to the surface of a substrate; (b) applying a
dry pigment material to the surface of the binder material, the
pigment material comprising flakes of a cholesteric liquid crystal
material, the pigment material adhering to the binder material; and
(c) repeating steps (a) and (b) a plurality of times of times to
build up a multipigmented pattern; wherein steps (a) and (b) are
performed using a printer selected from the group consisting of
inkjet printers, bubble jet printers, xerographic printers, and
laser printers.
67. The method of claim 66 wherein the binder material comprises a
fluid material.
68. The method of claim 66 wherein the binder material comprises a
fusible material.
69. The method of claim 66 wherein the binder material comprises a
radiation curable material.
70. The method of claim 66 wherein the binder material comprises a
mixture, the mixture comprising a non-volatile and a volatile
solvent.
71. The method of claim 66 further comprising the step of: (d)
mechanically working the surface of the binder to align the flakes
in a direction that is substantially parallel thereto.
72. The method of claim 71 wherein the step (d) comprises the step
of rolling the surface of the binder material.
73. The method of claim 71 wherein the step (d) comprises the step
of buffing the surface of the binder material.
74. The method of claim 66 wherein the flakes of cholesteric liquid
crystal material comprise a non-linear pitch distribution to
reflect a broad band of light.
75. The method of claim 66 further comprising the step of: (d)
applying a protective coating over the dry pigment material.
76. A method of producing a pattern on a surface of a substrate,
the method comprising the steps of: (a) applying a patterned coat
of a binder material to the surface of a substrate; (b) applying a
dry pigment material to the surface of the binder material, the
pigment material comprising flakes of a cholesteric liquid crystal
material, the pigment material adhering to the binder material; and
(c) repeating steps (a) and (b) a plurality of times of times to
build up a multipigmented pattern; (d) mechanically working the
surface of the binder to align the flakes in a direction that is
substantially parallel thereto; wherein steps (a) and (b) are
performed using a printer selected from the group consisting of ink
jet printers, bubble jet printers, xerographic printers, and laser
printers; step (d) is performed using a technique selected from the
group consisting of rolling the surface of the binder material and
buffing the surface of the binder material; and wherein the flakes
of cholesteric liquid crystal material comprise a non-linear pitch
distribution to reflect a broad band of light.
77. The method of claim 76 wherein the binder material comprises a
fluid material.
78. The method of claim 76 wherein the binder material comprises a
fusible material.
79. The method of claim 76 wherein the binder material comprises a
radiation curable material.
80. The method of claim 76 wherein the binder material comprises a
mixture, the mixture comprising a non-volatile and a volatile
solvent.
81. The method of claim 76 further comprising the step of: (e)
applying a protective coating over the dry pigment material.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] This document describes a technology for painting and image
printing that utilizes a simple system with multiple colorants and
a single printing head through which the image is printed by a
transparent ink or binder. The primary area of interest involves
dry pigments of larger molecular weight colorants, such as
cholesteric liquid crystal (CLC) pigments, and their diverse
applications in modern printing and painting. In addition, new
techniques can be easily expanded to serve more functions, such as
3-D stereoscopic image capability.
[0003] 2. Brief Description of the Literature
[0004] Broadband reflecting polarizers were introduced in
application Ser. No. 08/550,022 (now U.S. Pat. No. 5,691,789)
entitled "Single Layer Reflective Super Broadband Circular
Polarizer and Method of Fabrication Therefor" by Sadeg M. Faris and
Le Li which was filed Oct. 30, 1995. Such broadband polarizers are
made by producing a single layer having cholesteric liquid crystal
order where the pitch of the liquid crystal order varies in a non
linear fashion across the layer.
[0005] General references on polymer dispersed liquid crystals may
be found in detail in "Polymer Dispersed Liquid crystal displays",
by J. W. Doane, a chapter in "Liquid Crystals", Ed. B. Bahadur,
World Scientific Publishing, Singapore, and "CLC/polymer dispersion
for haze-free light shutters, by D. Yang et al. Appl. Phys. Lett.
60, 3102 (1992).
[0006] Since the early attempt of utilizing cholesteric film as
optical filters and the effort on polymer encapsulated nematic
liquid crystals for display, much attention has been focused on
trying to bring polymeric liquid crystals and cholesteric liquid
crystals together to make devices for light control application.
(See, for example J. Adams, W. Hass, J. Dailey, Journal of Applied
Physics, 1971, and J. L. Fergason, Society for Information Display
Digest, 1985). The above identified U.S. patents and other
references are hereby incorporated by reference.
[0007] Related Cases
[0008] The following applications are related to the present
invention: application Ser. No. 9/093,017 filed Jun. 5, 1998;
application Ser. No. 09/093,006 filed Jun. 5, 1998; application
Ser. No. 09/039,303 filed Mar. 14, 1998; application Ser. No.
09/039,297 filed Mar. 14, 1998; application Ser. No. 08/891877
filed Jul. 9, 1997 entitled "Reflective Film Material Having
Symmetrical Reflection Characteristics and Method and Apparatus for
Making the Same", by Le Li and Sadeg Faris application Ser. No.
08/739467 filed Oct. 29, 1996 entitled "Circularly Polarizing
Reflective Material Having Super Broad-Band Reflecting &
Transmission Characteristics & Method of Fabricating &
Using Same in Diverse Applications" by Sadeg M. Faris, Le Li, and
Yingqiu Jiang Jiang. Application Ser. No. 08/890320 filed Jul. 9,
1997 entitled "Coloring Media Having Improved Brightness and Color
Characteristics" by Sadeg M. Faris and Le Li application Ser. No.
08/805,603 entitled "Electro-optical glazing structures having
total-reflection and transparent modes of operation for use in
dynamical control of electromagnetic radiation" by Sadeg M. Faris
and Le Li, filed Feb. 26, 1997, which is a continuation-in-part of:
copending application Ser. No. 08/739,467 entitled "Super Broadband
Reflective Circularly Polarizing Material And Method Of Fabricating
And Using Same In Diverse Applications", by Sadeg M. Faris and Le
Li filed Oct. 29, 1996, which is a is a Continuation-in-Part of
application Ser. No. 08/550,022 (Now U.S. Pat. No. 5,691,789)
entitled "Single Layer Reflective Super Broadband Circular
Polarizer and Method of Fabrication Therefor" by Sadeg M. Faris and
Le Li filed Oct. 30, 1995; application Ser. No. 08/787,282 entitled
"Cholesteric Liquid Crystal Inks" by Sadeg M. Faris filed Jan. 24,
1997, which is a Continuation of application Ser. No. 08/265,949
filed Jun. 2, 1994, which is a Divisional of application Ser. No.
07/798,881 entitled "Cholesteric Liquid Crystal Inks" by Sadeg M.
Faris filed Nov. 27, 1991, now U.S. Pat. No. 5,364,557; copending
application Ser. No. 08/715,314 entitled "High-Brightness Color
Liquid Crystal Display Panel Employing Systemic Light Recycling And
Methods And Apparatus For Manufacturing The Same" by Sadeg Faris
filed Sep. 16, 1996; copending application Ser. No. 08/743,293
entitled "Liquid Crystal Film Structures With Phase-Retardation
Surface Regions Formed Therein And Methods Of Fabricating The Same"
by Sadeg Faris filed Nov. 4, 1996. Each of the above identified
Applications and patents are commonly assigned to the assignee of
the present invention, and are incorporated herein by reference in
their entirety.
INTRODUCTION
[0009] In modern society, information exchange plays an important
role. Efficient methods to convey information rely on high-quality
communication devices. Among them, printing and painting devices
are becoming more and more important. Currently, ink-jet, bubble
jet, and laser printing, along with off-set, flexo press, and
screen printing are universally used. All of these printing
techniques possess a common feature. In order to perform color
printing, multiple nozzles or screens must be used for cyan,
magenta, yellow and black colorants. This forces the printing
system to become mechanically complex and limits the system from
being able to be expanded to serve multiple functions such as the
case of 3-D printing. In addition, since the printing nozzles and
screens have a very fine apertures, they can't handle those
colorants with relatively larger pigment particles.
[0010] Furthermore, it has been known that CLC can be used as a
colorant for painting and printing because of their excellent
spectral characteristics and wide color range properties. However,
special techniques must be employed in order to use CLC. Special
surface treatments and curing methods are all necessary to print
and dry CLC films. As a result, CLC has never been practically used
in real artwork or other applications. However, the present
invention of the new CLC ink based on CLC pigment solves all these
problems at once. No special surface treatment and curing equipment
is required to dry and/or cure the colorant. Another benefit is the
capability of generating colorful 3-D stereoscopic images since the
CLC ink reflects polarized light.
OBJECTS OF THE PRESENT INVENTION
[0011] One objective of this invention is to improve today's
printing technologies. The inventors of the present invention have
developed a new printing technology that offers a simple system
configuration, greater flexibility, improved printing quality, and
enhanced functionality. The new technique is termed Dry Printing
Technology (DPT) by its working principle. It uses only one
printing head and prints images with an invisible ink. It can
handle, in principle, all kinds of colorants, even colorants with
larger pigments so that it removes the pigment size constraint in
ink jet nozzle printing. By adopting a new printing head combined
with CLC pigments, dry printing offers enhanced image quality.
Finally, DPT can be easily expanded to print a colorful picture in
3-D with the CLC pigments.
[0012] Another objective is the application of the invented
printing technique using a newly developed, novel colorant to
achieve unique display effects that usual technologies do not
possess. The ink is made from CLC pigments mixed into a suitable
optically clear carrier.
[0013] Yet another objective is to give printing devices more
flexibility and enhance their functionality.
[0014] Yet another objective is to achieve a special visual effect
of objects which appear to have different colors depending on the
viewing angle.
[0015] Yet another objective is to create 3-D stereoscopic images
in full color at any size.
[0016] Yet another objective is to provide security printing
[0017] Yet another objective is to provide unique cosmetic
effects.
[0018] Other objects, advantages, and novel features of the present
invention will become apparent from the following detailed
description of the invention when considering in conjunction with
the accompanying drawings.
SUMMARY OF THE PRESENT INVENTION
[0019] The present invention provides a method of using flat flakes
of non metallic reflecting pigment by applying the flakes to a
surface and ensuring that the flakes lie substantially parallel to
the surface. A binder material may first be adhered to the surface
in a pattern or uniformly. The flakes are applied to the surface,
and stick where the binder has been prepared. The flakes are
applied so that they lie parallel to the surface, or the flakes are
applied, then rolled or buffed to align them parallel to the
surface. If the flakes are CLC flakes, multilayer polymer flakes,
or multilayer inorganic material flakes, an iridescent film which
changes color with viewing angle may be produced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 shows a prior art "paint layer".
[0021] FIG. 2 shows a pigment material is in the form of
flakes.
[0022] FIG. 3 shows a flow chart of the apparatus of the
invention.
[0023] FIG. 4 shows an embodiment of the invention.
[0024] FIG. 5 shows an embodiment of the invention.
[0025] FIG. 6 shows an alternative embodiment of the invention
[0026] FIG. 7 is a flow chart of the method of the invention.
[0027] FIG. 8 is a flow chart of a preferred embodiment of the
invention.
[0028] FIG. 9 shows a flow chart of a preferred embodiment of the
invention.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0029] The present invention, termed "Dry Printing Technology"
(DPT), enables many new applications to surface. The central part
of the new technology is to print an image with an optically clear
ink through a single printing head followed by an applying of CLC
pigments.
[0030] FIG. 1 shows an object 10 having a surface 12 covered with a
prior art "paint layer" 14. The paint layer 14 generally comprises
pigment particles 16 dispersed in a binder material 18.
[0031] FIG. 2 shows a paint layer like FIG. 1 where the pigment
material is in the form of flakes 20. The flakes 20 are shown
randomly dispersed in the binder material 18. For reflective non
metallic pigment particles like CLC flakes, multilayer polymer
material flakes, or inorganic multilayer material flakes which have
reflectivity by virtue of the interference effect of light
reflection from a spatially varying index of refraction, the angle
of viewing is critical, and no coherent effect is gained when the
eye sees a large collection of pigment particles at may different
angles. The use of CLC flakes is described in detail in application
Ser. No. 08/787,282 entitled "Cholesteric Liquid Crystal Inks" by
Sadeg M. Faris filed Jan. 24, 1997, and in application Ser. No.
07/798,881 entitled "Cholesteric Liquid Crystal Inks" by Sadeg M.
Faris filed Nov. 27, 1991, now U.S. Pat. No. 5,364,557. Multilayer
polymer reflecting material in sheet form and flake form is well
known, as are multilayer inorganic coating for reflective and
antireflective coatings optical substrates. The CLC flakes can be
manufactured so that the pitch of the helix of the CLC molecules is
non-linear, as detailed in the above mentioned patent applications,
and so the flakes are broad band reflectors. In a similar way, the
pitch of the polymer and inorganic multilayer films can be changed
throughout the films to produce broad band reflecting flakes.
[0032] FIG. 3. shows a flow chart of apparatus of the the
invention. The Image Generator 30, which may be a computer,
photograph, silk screen, image plate, or manual drawing, provides
the information to be printed. The image is transmitted to a means
for applying a binder material, or the Binder Material Applicator
module 32, which is one of the fundamental components of the Dry
Printing technology. Pictures or images are printed in the most
preferred embodiment using a transparent ink or binder material
rather than a conventional colorant. Transparent binder material
allows the printing process to be repeated many times to build
layers of different color pigment material. An alternative
embodiment allows use of a light absorbing binder material to bind
light reflective pigment particles. Light which is not reflected
from the pigment particles passes through the pigment particles and
is absorbed in the light absorbing binder so that only the color
reflected from the pigment particles may be seen.
[0033] Equally important, the means for transparent ink or binder
printing may employ techniques from most printing technologies. For
example, ink-jet, bubble jet, and laser printing, as well as flexo
press, off-set, gravure printing and silk screen printing may serve
as the methods and apparatus for transparent ink printing in module
32 However, minor changes and/or modifications might be required to
the pre-existing printing systems to account for transparent ink
printing conditions such as printing heat or environment. Printing
with a binder or invisible ink allows the use of pigment particles
of any size, since the pigment particles do not have to pass
through the nozzles, screens, or other devices used to print
normally. While particles and flakes of less than 40 or 50 microns
diameter give good resolution and pass through most printers
without clogging, larger pigments particles which may be used for
special effects are difficult to use.
[0034] Dry Pigment Application by module 34 is another central part
of the unique dry printing process. Before the invisible ink
pattern provided by module 32 is completely cured, dry pigments are
applied by module 34 to the ink surface to cover the printed area.
The dry pigments adhere to the patterned surface in the pattern
printed by the means for applying binder material 32. The dry
pigments may be removed from the surface which has no binder
material by shaking, vacuuming, or other standard way of removing
dry powder from a surface. The dry pigments are, in the most
preferred embodiments, either commercially available, conventional
absorptive pigments or the novel non metallic reflecting CLC
pigments or other iridescent flakes. Flakes of other absorptive
pigment materials are also anticipated by the inventors. The CLC
flakes and other multilayer flakes give spectacular reflective
layer effects, and may also be used in transmission, for they
transmit those colors which they do not reflect. Other dry pigments
are also anticipated by the inventors. Dry pigment applicator 34
may contain multiple colorants, such as reflective red, green,
blue, and white (RGBW) pigments, which are applied onto a black
surface; or, absorptive cyan, magenta, yellow, and black (CMYB)
pigments that are applied onto a white surface.
[0035] Furthermore, the applicator 34 may have another mechanism 35
to mechanically align pigments, which is of great importance in the
usage of CLC pigments or other pigments which are in the form of
flakes. As a result, all the dry flake pigments are uniformly
oriented and layered on the flat surface. The output device 36
allows for the visualization of the colorful image. The output
device 36 may also include a means for returning the object being
printed to the binder material applicator 32 to apply another
pattern for another color pigment or for another polarization
reflecting pigment. The output device 36 may also have a device for
applying a protective coating to protect the binder layer and
pigment layer or layers.
[0036] FIG. 3 may also be used to describe a process whereby no
image is printed in transparent ink printing module 32, but a
uniform coating of binder material is laid on a surface, such as
the surface of an automobile, and dry pigments are applied to the
surface by device 34 to produce striking effects using CLC pigment
flakes. The CLC pigment flakes may be composed of two layers, a
left handed polarization layer and a right handed polarization
layer, whereby light incident on the flake is 100% reflected. Such
flakes may be produced, for example, by coating a layer of
alignment material such as polyimide on to a flat surface, buffing
the polymide surface to produce an aligned surface layer,
deposition of a first polarization CLC coating on the aligned
surface layer to produce a reflector of light of a first
polarization, and immediately depositing a layer of a second
polarization CLC material on to the first polarization CLC coating.
The top surface of the first polarization CLC coating is itself
aligned and will force the second polarization CLC coating to align
and act as a reflector for light of the second polarization.
Thereafter the first polarization and second polarization coatings
are removed in the form of flakes which are reflective of both
polarizations.
[0037] FIG. 3 may also be used to describe a process whereby a
uniform coating of binder material is laid on a surface in
transparent ink printing module 32, and dry pigments are applied to
the surface in a pattern in module 34. The pattern is then fixed by
fusing or otherwise curing the binder material.
[0038] FIG. 4 shows an object 10 which has a binder coating 40
applied to the surface 12 of the object. Pigment flakes 20 have
been applied to the surface of the binder coating 40, and are being
rolled or buffed by the object 42 so that the pigment flakes 20 lie
substantially parallel with the surface 12 of the object 10.
[0039] FIG. 5 shows the result of the preparation of FIG. 4 when
another layer 50 of material is applied over the flakes 20 and
binder material 40 as a protective layer. It is an embodiment of
the invention to have either the binder material 40 or the material
of protective layer 50 or both have an index of refraction equal to
the mean index of refraction of the flakes 20. In this way, light
will not scatter from the edges of the flakes 20 and wash out the
iridescent effects gained by the interference of light within the
flakes 20.
[0040] FIG. 6 shows an alternative embodiment of the invention
where the flakes 20 are electrically charged and caused to lay down
on the surface of the binder material by an electrical field at the
surface of the binder material 40. If the dimensions of flakes 20
are sufficiently large compared to the thickness of flakes 20, the
flakes will lie down substantially parallel to the surface 12. Such
techniques allow the use of flakes 20 with large length and width
dimensions compared with the thickness of the flakes 20. A
brilliant sparkling effect is created when flakes 20 are larger
than 100 microns. Even more preferred are flakes with mean
transverse dimensions greater than 150 microns.
[0041] FIG. 7 is a flow chart of the method of the invention. Step
70 involves applying a binder material to the surface of the
object. The binder material may be patterned or unpatterned. In a
preferred embodiment, the binder material is applied as a liquid in
a pattern, and the dry pigment material is applied in step 74
directly to the patterned binder material while the binder material
is wet. The dry pigment sticks to the wet binder material, and may
be shaken off or otherwise removed from the surface of the object
where no binder material has been applied. In a preferred
embodiment, the pigment material is rolled or buffed in step 76 to
align the pigment material flakes parallel to the surface of the
object. In another preferred embodiment, the binder material may be
dry, and the surface prepared in step 72 in a pattern by applying a
solvent material such as water to the surface in a pattern so that
the pigment material sticks in a pattern. In another embodiment,
the surface of the object may be coated with a binder material that
may be fused, like a wax. The binder material is fused in a pattern
and the pigment material applied so that the pigment material
sticks to the fused binder material In another embodiment, the
binder material may be coated with dry pigment first, and the
binder material fused or coated with a solvent to "fix" the pigment
material in a pattern. It is generally preferred that the dry
pigment material is not fused in the fixing operation of fusing the
binder material. A final step involves applying a protective
coating in step 78. The protective coating may be transparent, or
may be colored for special effects. The index of refraction of the
protective coating 78 may match the mean index of refraction of the
flakes in order to cut down scattering from the edges of the
flakes. The index of refraction of the binder material may also
match the mean index of refraction of the flakes for the same
reason.
[0042] FIG. 8 is a flow chart of a preferred embodiment of the
invention where a binder material is coated on the surface of an
object in step 80, and then flakes of pigment are deposited in a
pattern. Such flakes can be deposited by electrostatic means as in
a xerographic photocopier, for example. After the flakes are
deposited in step 82, the surface of the object may be worked by
rolling or buffing to align the flakes parallel to the surface as
shown in step 84. The flakes may be firmly adhered to the surface
in step 86 by treating the surface with a solvent or by fusing the
binder material. Once again, the surface may be protected by
applying a protective layer in step 88.
[0043] FIG. 9 shows a flow chart of a preferred embodiment of the
invention, in that the steps of the previous embodiments discussed
above may be repeated in steps 90, 92, 94, 96 and 99 for different
colors of pigments or different polarization reflection
characteristics of pigments. The decision step 98 sends the system
back around the loop until the required multiple color or multiple
dimension image is complete.
[0044] The following is a detailed description encompassing
specific applications of transparent printing as well as pigment
application utilized in present printing technology processes. RBGW
colorants will be used in the discussion, however, cyan, magenta,
yellow and black (CMYB) colorants are also applicable.
[0045] 1. DPT Via Printing Screen
[0046] In this technology, the printing screen carries the image to
be printed. One screen is needed for each one color printing. To
print colorful image, four screens are needed that represent red,
green, blue, and white (RGBW) colorants. For printing in 3-D using
RGBW CLC colorants, eight screens are then needed. The first four
(RGBW) are for the right image perspective, and the other four
(RGBW) for the left image perspective. Typically, reflective
pigments are applied to a black background which absorbs all the
light which is not reflected, while absorptive pigments are applied
to a white background which reflects all light which is not
absorbed. To print single color pictures, the optically clear ink
image is printed onto the substrate through the screen. Before the
ink has completely dried, CLC pigments are spread onto the surface
of the carrier followed by a mechanical alignment brush. If
necessary, a top coating will be applied to protect the image.
[0047] To print full color image, RGBW is printed in an arbitrary
sequence. For example, the red image is printed in transparent ink
onto the carrier through the "red color" screen. Then red CLC
pigments are applied. Next, after the red image has completely
dried, the green image is printed using the appropriate image
screen and green CLC pigments are applied. The same procedure is
then applied to printing the blue and white images. To print
colorful image in three dimensions, the above procedure is repeated
for both left and right image perspectives with left and right
handed RGBW CLC pigments.
[0048] 2. DPT Via Painting Brush/Spray
[0049] This technology is particularly important in, but not
limited to, painting an object such as an automobile. First of all,
a carrier (such as a primer etc.) is painted onto an object via
sprayer or brush. Before the carrier dries, the CLC pigments are
spread onto the object followed by mechanical brushing to orient
the CLC pigments. Finally, a protective coating is applied over the
CLC paint if necessary.
[0050] This method can also be used to paint colorful pictures in
3-D in large size. The procedure is very similar to the screen
printing technology described above.
[0051] 3. DPT Via Xerox/Laser Printer
[0052] The existing photo xerography and laser printing
technologies can be modified to use the CLC pigments as their
colorants. In these processes, the black carbon toner is replaced
with CLC pigments. As experimentally proven, CLC pigments can be
easily charged via static electric field, which is a necessary
condition for Xerox and laser printing. In contrast to the
xerography process, the pigment particles are not fused to the
uncoated paper, but the non-fusible pigment particles which are
deposited on a binder coated paper are fixed to the paper by
fusing, for example, the binder material. The sheet being printed
is stable after one color is printed, and may be sent through the
same or another xerography process to add other colors or other
polarization CLC flakes to the partially printed sheet.
[0053] 4. DPT Via Ink Jet Printer/Bubble Jet Printer
[0054] The same principal is applied in this case as in the
screen-printing. The image is printed using the clear carrier
through the ink jet or bubble jet printer. Then, the CLC pigments
are applied before the carrier is dried followed by a mechanical
brushing for alignment. The same procedure as with screen-printing
is applied for printing full color pictures as well as color 3-D
images.
[0055] 5. DPT Via Wax Printer
[0056] First, the wax binder layer, which may be coated on a thin
film or on a paper sheet, is thermally melted. Then, the CLC
pigments are sprayed onto the "wet" wax surface followed by a
mechanical brush before the wax solidifies. In an alternative
embodiment, the CLC pigments are deposited in a pattern and aligned
on wax which is coated onto a thin film. RGB and White CLC wax
foils are prepared in a similar way. The image may be transferred
from a foil to paper by pressing the foil and paper together and
heating to transfer the wax and the pigment from the foil to the
paper surface. Therefore, an image is printed. If RGB and white wax
foils are made with left and right handed CLC pigments separately,
then colorful 3-D printing will be achieved via this
technology.
[0057] 6. DPT Via Off-Set Printer and Gravure Printer
[0058] A similar technique used for screen printing can be used in
off-set printing technology as well. Image is first printed with
the clear carrier. Then CLC pigments of one color are sprayed and
brushed before the carrier is completely dried. Also, the 3-D
picture can be printed with the left and right handed CLC
pigments.
[0059] 7. DPT on Pre-Treated Substrates
[0060] This method applies to all the printing technologies
mentioned above. Rather than printing images with a clear carrier,
which is either thermally or photon curable, this technique prints
the image with a solvent or a solution, which reacts with
pre-coated surface on the substrate. For example, the solvent can
be water and the agent that is pre-coated on the substrate surface
is polyvinyl alcohol (PVA). It is well known that PVA is
dissolvable into water. In this particular case, image is printed
onto the substrate surface with the water through the printer head.
Before the water dries, the CLC pigments are sprayed and brushed.
This principle can be further generalized to create colorful
pictures by screen printing, off-set, Gravure, ink jet, bubble jet,
Xerox or laser printing and even in 3-D. In addition, this method
is also suitable for painting. Further generalization of this
technology can yield another method. The object to be painted is
first wholly painted with a wet carrier that might be thermally or
TV curable. Then, a pattern is printed with a fast drying coating
through a printing device. The area covered by this coating is no
longer sticky to the CLC pigments. However, the remaining area
where not covered with such coating can still adhere to the CLC
pigments. Therefore, image is created. This method is then termed
as "negative" as compared to the previous methods.
[0061] Furthermore, the new printing technologies can be
generalized to the situation where ordinary absorptive CMYB
pigments are used instead of the CLC pigments.
[0062] Applications of the New Invention
[0063] There are many applications that may be explored using this
new printing technology. A first application is in automobile
painting. Using the new painting technology, CLC pigments can be
painted flat onto an automobile body such that a color change
occurs when viewing angle changes.
[0064] A second important application is security printing. CLC
pigments are printed flat using the new technology to ensure a
color change versus the viewing angle. This characteristic is
difficult to counterfeit. In addition, the security pattern will
change when viewed with circular polarizing filters. Of great
interest in this area is the usage of IR CLC pigments which are
particularly suitable for machine vision application.
[0065] A third application is in general painting using CLC or
multilayer organic or inorganic reflective pigments as the colorant
for decoration as well as for energy saving. Since the light energy
is not absorbed, but reflected, less energy will be used for air
conditioning in a house painted with reflective paint.
[0066] A fourth application is in cosmetics. CLC pigments used as
finger nail polish, skin colorants, and eyeshadow offer spectacular
effects. In particular, binder material applied first to a
fingernail, then flakes which are rubbed to align them are very
effective. Very large flakes of about 100 or 150 microns give a
striking "glitter" effect. One other example is the use of such
reflective pigments in sunblock. Multilayer flakes with a non-liner
pitch may reflect a broad band of wavelengths, and in particular
block ultraviolet light in the UVA and UVB bands. Normal sunblock
lotion uses organic molecules to absorb the ultraviolet light, but
the bandwidth of such molecules is normally too small to
effectively block both the UVA and UVB bands. Pigment materials
such as zinc oxide and titanium dioxide are very white, and are not
appealing. Broadband reflecting flakes, however, reflect the
ultraviolet light and are colorless in the visible spectrum. Such
broadband reflecting flakes may also reflect the infrared light as
well and lead to a cooling effect when the infrared rays of the sun
are reflected from the skin instead of absorbed by the skin. Flakes
of such broadband ultraviolet and infrared reflecting
characteristics and visible transmitting characteristics are
anticipated by the inventors.
[0067] The methods noted above are examples which may be
generalized by one of skill in the art to provide many additional
embodiments which are anticipated by the inventors.
[0068] Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. It is
therefore to be understood that, withing the scope of the appended
claims, the invention may be practiced otherwise then as
specifically described.
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