U.S. patent application number 10/047296 was filed with the patent office on 2002-08-29 for head-up display system utilizing fluorescent material.
Invention is credited to Snider, Albert Monroe JR..
Application Number | 20020120916 10/047296 |
Document ID | / |
Family ID | 26724854 |
Filed Date | 2002-08-29 |
United States Patent
Application |
20020120916 |
Kind Code |
A1 |
Snider, Albert Monroe JR. |
August 29, 2002 |
Head-up display system utilizing fluorescent material
Abstract
A display system useful as a head-up display for vehicles, such
as aircraft, automobiles, trucks, etc., includes a fluorescent
material that can be carried on a support. The head-up display
system further includes a projection assembly having an
electromagnetic radiation source. The projection assembly is
configured to direct electromagnetic radiation of one or more
selected wavelengths toward the support to cause the fluorescent
material to fluoresce and form an image.
Inventors: |
Snider, Albert Monroe JR.;
(Pittsburgh, PA) |
Correspondence
Address: |
Andrew C. Siminerio, Esq.
PPG Industries, Inc.
One PPG Place
Pittsburgh
PA
15272
US
|
Family ID: |
26724854 |
Appl. No.: |
10/047296 |
Filed: |
January 14, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60262146 |
Jan 16, 2001 |
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Current U.S.
Class: |
717/100 ;
313/483 |
Current CPC
Class: |
G02B 2027/012 20130101;
G02B 27/01 20130101; B32B 17/10669 20130101; B32B 17/1022 20130101;
G02B 23/12 20130101; B32B 17/10761 20130101; G02B 2027/014
20130101; G02B 2027/0118 20130101; G02B 27/0101 20130101; B32B
17/10834 20130101; Y10S 428/913 20130101; Y10T 428/315 20150115;
B32B 17/10036 20130101; B32B 17/10201 20130101 |
Class at
Publication: |
717/100 ;
313/483 |
International
Class: |
G06F 009/44 |
Claims
What is claimed is:
1. A display system, comprising: at least one fluorescent material
having an absorption band; and a projection assembly having an
electromagnetic radiation source, the projection assembly
configured to direct radiation of one or more selected wavelengths
within the absorption band of the fluorescent material toward the
fluorescent material to cause at least a portion of the fluorescent
material to fluoresce.
2. The system as claimed in claim 1, wherein the fluorescent
material is carried on a support.
3. The system as claimed in claim 2, wherein the support is a
laminated article having a first ply and a second ply.
4. The system as claimed in claim 3, wherein the fluorescent
material is located between the first and second plies.
5. The system as claimed in claim 2, wherein the support is a
monolithic article.
6. The system as claimed in claim 2, including a functional coating
located on the support.
7. The system as claimed in claim 2, wherein the support is an
automotive transparency.
8. The system as claimed in claim 3, wherein at least one of the
first and second plies is selected from glass, plastic, and
ceramic.
9. The system as claimed in claim 7, wherein at least one of the
first and second plies is selected from annealed glass, tempered
glass, and heat strengthened glass.
10. The system as claimed in claim 3, including an interlayer
located between the first and second plies, with the fluorescent
material located between the first ply and the interlayer.
11. The system as claimed in claim 9, including a functional
coating located between the second ply and the interlayer.
12. The system as claimed in claim 9, wherein the interlayer is
selected from polyvinyl butyral, plasticized polyvinyl chloride,
and polyethylene terephthalate.
13. The system as claimed in claim 1, wherein the projection
assembly is controlled to cause the fluorescent material to form an
image.
14. The system as claimed in claim 1, wherein the support has a
first portion that is substantially transparent to the one or more
selected wavelengths and a second portion that is substantially
non-transparent to the one or more selected wavelengths.
15. The system as claimed in claim 1, wherein the electromagnetic
radiation source includes a laser or laser diode.
16. The system as claimed in claim 1, wherein the radiation is in
the range of 300 nm to 410 nm.
17. The system as claimed in claim 1, wherein the projection
assembly includes a controller configured to selectively direct the
radiation toward one or more selected areas of the fluorescent
material.
18. The system as claimed in claim 1, wherein the projection
assembly includes a directing system configured to direct the
radiation from the radiation source toward the fluorescent
material.
19. The system as claimed in claim 18, wherein the directing system
comprises at least one mirror.
20. The system as claimed in claim 18, wherein the directing system
includes a movement device configured to direct the radiation
toward at least a selected area of the fluorescent material.
21. The system as claimed in claim 1, wherein the display system is
a head-up display system.
22. The system as claimed in claim 1, wherein the support is
selected from a commercial window, a residential window, a
commercial sign, an advertising display, and an insulating glass
unit.
23. A vehicle head-up display, comprising: at least one fluorescent
material having an absorption band; and a projection assembly
configured to direct radiation of one or more selected wavelengths
within the absorption band of the at least one fluorescent material
toward the fluorescent material to cause at least a portion of the
fluorescent material to fluoresce.
24. A vehicle head-up display, comprising: a windshield having a
first ply and a second ply; at least one fluorescent material
having an adsorption band and located between the first and second
ply; and a projection assembly having an electromagnetic radiation
source and configured to direct radiation of one or more selected
wavelengths within the absorption band toward the fluorescent
material to cause at least a portion of the fluorescent material to
fluoresce to form an image.
25. A method of displaying images, comprising the steps of:
selectively directing electromagnetic radiation from a radiation
source toward a support having at least one fluorescent material;
and controlling the radiation source to cause the fluorescent
material to fluoresce to form an image.
26. The method as claimed in claim 25, including defining a
plurality of scan paths on at least a portion of the fluorescent
material and selectively energizing and deenergizing the radiation
source along the scan paths to form the image.
27. The method as claimed in claim 26, including: directing the
electromagnetic radiation in a first direction along a first scan
path while selectively energizing and deenergizing the radiation
source; displacing the electromagnetic radiation in a second
direction substantially perpendicular to the first direction; and
directing the electromagnetic radiation in a third direction
substantially parallel to the first direction while selectively
energizing and deenergizing the radiation source.
28. The method as claimed in claim 25, wherein the support is an
automotive transparency and the method includes moving the
radiation along at least a portion of the automotive transparency
to form the image.
29. The method as claimed in claim 27, including energizing and
deenergizing the radiation source to form adjacent fluorescent and
non-fluorescent areas on the support.
30. The method as claimed in claim 27, including blocking and
unblocking radiation from the radiation source to form adjacent
fluorescent and non-fluorescent areas on the support.
31. A vehicle having a head-up display as claimed in claim 24.
32. A display system, comprising: at least one light emitting
material having an absorption band; and a projection assembly
having an electromagnetic radiation source, the projection assembly
configured to direct radiation of one or more selected wavelengths
within the absorption band of the light emitting material toward
the light emitting material to cause at least a portion of the
light emitting material to emit light.
33. The system as claimed in claim 32, wherein the light emitting
material is selected from the group consisting of fluorescent
materials, phosphorescent materials, and mixtures thereof.
34. The system as claimed in claim 33, wherein the system is a
vehicle head-up display.
35. A method of displaying images, comprising the steps of:
selectively directing electromagnetic radiation from a radiation
source toward a support having one or more light emitting
materials; and controlling the radiation source to cause the light
emitting material to emit light to form an image.
36. The method as claimed in claim 35, wherein the light emitting
material is selected from the group consisting of fluorescent
materials, phosphorescent materials, and mixtures thereof.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefits of U.S. patent
application Ser. No. 60/262,146 filed Jan. 16, 2001, which is
herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to image and/or information
display systems and, in one embodiment, to an improved display
system utilizing fluorescent material(s) which is particularly
useful in a vehicle head-up display system.
[0004] 2. Technical Considerations
[0005] A head-up display (HUD) system displays information, such as
an image, to a viewer while the viewer simultaneously views the
real world around and through the displayed image. Head-up display
systems are often incorporated into aircraft cockpits for pilots to
monitor flight information. More recently, head-up display systems
have been used in land vehicles, such as cars, trucks, and the
like. The displayed image is generally positioned so that the
vehicle operator can see the image from a normal operating position
and does not have to glance downwardly to the vehicle dashboard and
away from the viewing area in front of the vehicle.
[0006] A conventional head-up display system typically includes a
matrix of light emitting diodes (LED) which can be selectively
illuminated to form an image. A collimator aligns the light rays
from the LEDs and directs them toward a combiner that reflects the
image toward the viewer. For automotive use, laminated windshields
have been used as the combiner. Examples of automotive head-up
display systems are disclosed, for example, in U.S. Pat. Nos.
2,264,044 and 5,013,134, and International Publication No. WO
91/06031, all of which are herein incorporated by reference.
[0007] While these known vehicle head-up display systems are
generally adequate for automotive use, improvements could be made.
For example, in these conventional automotive head-up display
systems the resolution of the reflected image is limited by the
size of the LED matrix, i.e., the number of rows and columns of
LEDs used to generate the image. Additionally, in strong sunlight,
the reflected image from the LED matrix can be difficult to read.
Further, reflection of the image from each of the interfaces of the
windshield, especially the air-glass interfaces, creates multiple
images that can reduce overall image clarity. Moreover, these
conventional head-up display systems are designed so that the
reflected image can be viewed only by the vehicle operator, not
vehicle passengers. Additionally, if the curvature of the
windshield deviates from designed specifications, the reflected
image can appear distorted and can be difficult to discern.
[0008] Therefore, it would be advantageous to provide an image
and/or information display system, particularly an automotive
head-up display system, which reduces or eliminates at least some
of the drawbacks discussed above.
SUMMARY OF THE INVENTION
[0009] The present invention provides a method of displaying images
and a display system, e.g., a head-up display system, which are
particularly useful in vehicles, such as aircraft, automobiles,
trucks, etc. The display system includes one or more light emitting
materials, such as one or more fluorescent and/or phosphorescent
materials, carried on a support and a projection assembly having an
electromagnetic radiation source. The projection assembly is
configured to direct electromagnetic radiation of one or more
selected wavelength(s) toward the light emitting material to cause
at least a portion of the light emitting material to emit light,
e.g., fluoresce or phosphoresce, to form an image. The
electromagnetic radiation source can be selectively directed and/or
controlled to generate a desired image. In one specific embodiment
of the invention, the support is a laminated windshield with
fluorescent material located between the plies of the laminate. The
windshield can have a first portion which is substantially
transparent to the selected wavelength(s) and a second portion
which is substantially non-transparent to the selected
wavelength(s). In another aspect, the support is a non-laminated
entertainment display.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic view (not to scale) of a head-up
display system for a vehicle which incorporates features of the
present invention;
[0011] FIG. 2 is a side view (not to scale) of a support with
fluorescent material incorporating features of the invention;
[0012] FIG. 3 is a front view of a fluorescent image formed in
accordance with the teachings of the present invention;
[0013] FIG. 4 is a schematic view (not to scale) of an alternative
embodiment of a projecting assembly for use with a head-up display
system of the invention; and
[0014] FIG. 5 is a graph of percent transmittance versus wavelength
comparing a clear glass ply to a laminated article described in
Example 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] As used herein, spatial or directional terms, such as
"inner", "outer", "left", "right", "up", "down", "horizontal",
"vertical", and the like, relate to the invention as it is shown in
the drawing figures. However, it is to be understood that the
invention can assume various alternative orientations and,
accordingly, such terms are not to be considered as limiting.
Further, all numbers expressing dimensions, physical
characteristics, and so forth, used in the specification and claims
are to be understood as being modified in all instances by the term
"about". Accordingly, unless indicated to the contrary, the
numerical values set forth in the following specification and
claims can vary depending upon the desired properties sought to be
obtained by the present invention. At the very least, and not as an
attempt to limit the application of the doctrine of equivalents to
the scope of the claims, each numerical parameter should at least
be construed in light of the number of reported significant digits
and by applying ordinary rounding techniques. Moreover, all ranges
disclosed herein are to be understood to encompass any and all
subranges subsumed therein. For example, a stated range of "1 to
10" should be considered to include any and all subranges between
(and inclusive of) the minimum value of 1 and the maximum value of
10; that is, all subranges beginning with a minimum value of 1 or
more and ending with a maximum value of 10 or less, e.g., 5.5 to
10. Also, as used herein, the terms "deposited over", "applied
over", or "provided over" mean deposited, applied, or provided on
but not necessarily in surface contact with. For example, a
material "deposited over" a substrate does not preclude the
presence of one or more other materials of the same or different
composition located between the deposited material and the
substrate.
[0016] In the following discussion, a display system incorporating
features of the invention will be discussed generally with
reference to use in a head-up display system for a vehicle, such as
an automobile. However, it is to be understood that the
specifically disclosed exemplary apparatus and method are presented
simply to explain the general concepts of the invention and that
the invention is not limited to these specific exemplary
embodiments. As would be appreciated by those skilled in the art,
the invention can be practiced in many fields, such as but not
limited to, laminated or non-laminated residential and/or
commercial windows, insulating glass units, commercial signs,
entertainment displays, advertising displays, monitors for
televisions or computers, and/or transparencies for land, air,
space, above water and under water vehicles, e.g., automotive
windshields, sidelights, back lights, sunroofs, and moon roofs,
just to name a few.
[0017] An exemplary display system incorporating features of the
invention is illustrated in FIG. 1 as a vehicle head-up display
system 10 and includes one or more light emitting materials, e.g.,
fluorescent or phosphorescent materials, carried on a support 12.
In the following discussion, the light emitting material is a
fluorescent material 11. The display system 10 also includes a
projection assembly 14. The components of the exemplary head-up
display system 10 shown in FIG. 1 will first be described and then
operation of the head-up display system 10 to practice an exemplary
method of the invention will be described.
[0018] The support 12 can be of any desired type, such as but not
limited to, a single ply or a laminated article. In the exemplary
embodiment shown in FIG. 1, but not to be considered as limiting to
the invention, the support 12 is shown as a laminated article
having a first ply 18 with a major surface facing the vehicle
interior, i.e., an inner major surface 20, and an opposed or outer
major surface 22. The support 12 also includes a second ply 24
having an inner major surface 26 and an outer major surface 28. The
first and second plies 18, 24 can be bonded together in any
suitable manner, such as by an interlayer 32. A conventional edge
sealant 34 can be applied to the perimeter of the laminated article
during and/or after lamination in any desired manner. A decorative
band 36, e.g., an opaque, translucent or colored shade band, such
as a ceramic band, can be provided on a surface of at least one of
the plies 18, 24, for example around the perimeter of the inner
major surface 20 of the first ply 18.
[0019] In the broad practice of the invention, the support 12
(e.g., the first and second plies 18, 24) can be of any desired
material having any desired optical characteristics. For example,
the plies 18, 24 can be transparent to visible light. By
"transparent" is meant having a transmittance of greater than 0% to
100%. By "visible light" is meant electromagnetic energy in the
range of 390 nm to 800 nm. Alternatively, the support 12 can be
translucent or opaque. By "translucent" is meant allowing
electromagnetic energy (e.g., visible light) to pass through but
diffusing it such that objects on the other side are not clearly
visible. By "opaque" is meant having a visible light transmittance
of 0%. The plies 18 and 24 can be of the same or different
materials.
[0020] For automotive use, the first and second plies 18, 24 are
each preferably made of a transparent material, such as plastic
(e.g., polymethylmethacrylate, polycarbonate, polyurethane,
polyethyleneterephthalate (PET), or copolymers of any monomers for
preparing these, or mixtures thereof), ceramic or, more preferably,
glass. The glass can be of any type, such as conventional float
glass or flat glass, and can be of any composition having any
optical properties, e.g., any value of visible transmission,
ultraviolet transmission, infrared transmission, and/or total solar
energy transmission. By "float glass" is meant glass formed by a
conventional float process in which molten glass is deposited onto
a molten metal bath and controllably cooled to form a float glass
ribbon. The ribbon is then cut and/or shaped and/or heat treated as
desired. Examples of float glass processes are disclosed in U.S.
Pat. Nos. 4,466,562 and 4,671,155. The glass can be, for example,
conventional soda-lime-silicate glass, borosilicate glass, or
leaded glass. The glass can be clear glass. By "clear glass" is
meant non-tinted or non-colored glass. Alternatively, the glass can
be tinted or otherwise colored glass. The glass can be untempered,
heat treated, or heat strengthened glass. As used herein, the term
"heat strengthened" means annealed, tempered, or at least partially
tempered. The first and second plies 18, 24 can each be clear float
glass or can be tinted or colored glass or one ply can be clear
glass and the other colored glass. Although not limiting to the
invention, examples of glass suitable for the first ply 18 and/or
second ply 24 are described in U.S. Pat. Nos. 4,746,347; 4,792,536;
5,240,886; 5,385,872; and 5,393,593, which are herein incorporated
by reference. The first and second plies 18, 24 can be of any
desired dimensions, e.g., length, width, shape, or thickness. For
use in automotive transparencies, the first and second plies 18, 24
can each be 1 mm to 10 mm thick, e.g., less than 10 mm thick, e.g.,
1 mm to 5 mm thick, e.g., 1.5 mm to 2.5 mm, e.g., 1.8 mm to 2.3
mm.
[0021] The interlayer 32 can be of any desired material and can
include one or more layers or plies. As will be described in more
detail below, the interlayer material can be a material selected to
block, absorb, or at least attenuate the transmission of
electromagnetic energy of one or more selected wavelengths. The
interlayer 32 can be a plastic material such as, for example,
polyvinyl butyral, plasticized polyvinyl chloride, or multi-layered
thermoplastic materials including polyethylene terephthalate, etc.
Suitable interlayer materials are disclosed, for example but not to
be considered as limiting, in U.S. Pat. Nos. 4,287,107 and
3,762,988, which are herein incorporated by reference. In the
exemplary embodiment shown in FIG. 1, the interlayer 32 is a single
polyvinyl butyral ply having a thickness of 0.5 mm to 1 mm, e.g.,
0.76 mm. The interlayer 32 secures the first and second plies 18,
24 together, provides energy absorption, reduces noise, and
increases the strength of the laminated structure. The interlayer
32 can also be a sound absorbing or attenuating material as
described, for example, in U.S. Pat. No. 5,796,055, which is herein
incorporated by reference. The interlayer 32 can have a solar
control coating provided thereon or incorporated therein or can
include a colored material to reduce solar energy transmission.
[0022] In the practice of the invention, the light emitting
material (e.g., fluorescent material 11) is carried on all or at
least a portion of the support 12, e.g., on all or at least a
portion of a major surface of the support 12. Alternatively, the
fluorescent material 11 can be on a surface of or incorporated into
the interlayer 32. The fluorescent material 11 can be applied in
any conventional manner, such as but not limited to dissolving the
fluorescent material 11 in a solvent and applying the resultant
solution onto the substrate by spraying, dipping, or rolling.
Alternatively, the dry fluorescent material 11 can be press-applied
onto one or more major surfaces of the substrate 12. In the
exemplary laminated support 12 shown in FIG. 1, the fluorescent
material 11 can be located between the first ply 18 and the second
ply 24, e.g., between the first ply 18 and the interlayer 32. For
example, the fluorescent material 11 can form a continuous coating
layer on all or at least a portion of the support 12.
Alternatively, the fluorescent material 11 can be present in
discreet sections or areas or can be present in non-film form, such
as inorganic crystalline powders or organic fluorescent materials
deposited on or carried on the support 12.
[0023] As used herein, the term "light emitting material" means a
material that emits electromagnetic radiation, e.g., in the visible
region of 390 nm to 800 nm, upon exposure to external radiation.
Exemplary light emitting materials suitable for the practice of the
invention include fluorescent and phosphorescent materials. In one
embodiment, the light emitting material (e.g., fluorescent material
11) absorbs electromagnetic energy in one region of the
electromagnetic spectrum (e.g., at one or more first wavelength(s))
and emits electromagnetic energy at another region of the
electromagnetic spectrum (e.g., one or more second wavelength(s)),
which can be different than the first wavelength(s). Typically,
although not required, the second wavelength(s) are longer than the
first wavelength(s). In one embodiment, the fluorescent material 11
absorbs electromagnetic energy in at least a portion of the visible
(390 nm to 800 nm) and/or ultraviolet (300 nm to 390 nm) ranges of
the electromagnetic spectrum, e.g., one or more wavelengths greater
than 300 nm, e.g., one or more wavelengths less than 800 nm, e.g.,
one or more wavelengths in the range of 300 nm to 800 nm. In a
particular embodiment of the invention, the fluorescent material 11
absorbs energy (e.g., one or more wavelengths) within a region of
the electromagnetic spectrum between 300 nm to 500 nm, such as in a
range of 325 nm to 425 nm, e.g., 350 nm to 410 nm, e.g., 397 nm.
The portion of the electromagnetic spectrum or wavelength(s) of the
electromagnetic spectrum absorbed by the light emitting material
(e.g., fluorescent material 11) is generally referred to herein as
the "absorption band" of the fluorescent material 11. The
fluorescent material 11 preferably fluoresces at one or more
wavelengths close to or in the visible range, such as between 380
nm to 800 nm of the electromagnetic spectrum.
[0024] The light emitting material, e.g., fluorescent material 11,
can be any type of light emitting material, such but not limited to
one or more organic, organo-metallic, or inorganic light emitting
(e.g., fluorescent and/or phosphorescent) materials, and can be
present in any desired amount. An example of one fluorescent
material 11 suitable for the practice of the invention is
Uvitex.RTM. OB fluorescent material commercially available from
Ciba Specialty Chemicals Corporation. Other suitable light emitting
organic materials include stibene, styrene, and ethylene species
supplemented with one or more heterocyclic substituents such as
benzoxazolyl, v-triazolyl, oxadiazolyl, or s-triazinylamino groups.
Other suitable inorganic light emitting materials include oxides,
sulfides, or oxide-sulfides of metals that are "doped" with (i.e.,
include small amounts of) ions of another metal, e.g.
Y.sub.2O.sub.3:Eu, YVO.sub.4:Tm, ZnS:Mn, Y.sub.2O.sub.2S:Pr, and
Gd.sub.2O.sub.2S:Tb. However, as will be understood by one of
ordinary skill in the art, the particular light emitting, e.g.,
fluorescent, material utilized can be selected based on the
electromagnetic radiation source used in the projection assembly 14
described below and/or by the desired wavelength of the light
emitted from the fluorescent material 11, such as to produce an
image of one or more desired colors. The amount of fluorescent
material 11 can be any amount to provide a desired level of
fluorescent brightness, i.e., the brightness of the fluorescent
image. As a general rule, as more fluorescent material 11 is placed
on the support 12, the brighter will be the resultant fluorescent
image until the point is reached where all of the incoming
electromagnetic energy is absorbed by the fluorescent material. In
addition to or in lieu of the fluorescent material 11, the
invention could also be practiced with phosphorescent material.
[0025] With continued reference to FIG. 1, a functional coating 42
can also be carried on the support 12. The functional coating 42
can be a coating which affects the solar properties, e.g.,
emissivity, shading coefficient, transmission, absorption,
reflection, etc., or conductive properties, e.g., thermal or
electrical conduction, of the support 12.
[0026] The functional coating 42 can be of any desired type. As
used herein, the term "coating" includes one or more coating layers
and/or coating films. The functional coating 42 can have one or
more functional coating layers or films of the same or different
composition or functionality. As used herein, the terms "layer" or
"film" refer to a coating region of a desired or selected coating
composition.
[0027] Although not limiting to the invention, the functional
coating 42 can be a coating which affects the solar control
properties, e.g., emissivity, shading coefficient, transmission,
absorption, reflection, etc., or conductive properties, e.g.,
thermal or electrical conduction, of the functionally coated
support 12. For example, but not to be considered as limiting, the
functional coating 42 can be an electroconductive coating, a
heatable coating, an antenna coating, or a solar control coating,
such as a low emissivity coating. As used herein, the term "solar
control coating" refers to a coating which affects the solar
properties of the coated article, such as but not limited to,
shading coefficient and/or emissivity and/or the amount of solar
radiation reflected and/or absorbed by and/or transmitted through
the coated article, e.g., infrared or ultraviolet absorption or
reflection. The solar control coating can block, absorb, or filter
selected portions of the solar spectrum, such as but not limited
to, the visible spectrum. Non-limiting examples of solar control
and antenna coatings are disclosed in U.S. Pat. Nos. 4,898,789;
5,821,001; 4,716,086; 4,610,771; 4,902,580; 4,716,086; 4,806,220;
4,898,790; 4,834,857; 4,948,677; 5,059,295; and 5,028,579, which
patents are herein incorporated by reference. Non-limiting examples
of electroconductive coatings are disclosed in U.S. Pat. Nos.
5,653,903 and 5,028,759, which are herein incorporated by
reference.
[0028] In one exemplary embodiment, the functional coating 42 can
be a low emissivity coating. As will be appreciated by one skilled
in the art, a "low emissivity" coating can have different
emissivity values depending upon how the coating is deposited. For
example, low emissivity sputter applied coatings typically have an
emissivity in the range of 0.01 to 0.06, depending on the number of
reflective metal layers present in the coating. Low emissivity
pyrolytically applied coatings typically have an emissivity in the
range of less than 0.03. Therefore, as generally used herein, the
term "low emissivity" means an emissivity less than 0.1, such as
less than 0.05. Examples of low emissivity coatings are found, for
example, in U.S. Pat. Nos. 4,952,423 and 4,504,109. The functional
coating 42 can be a single layer or multiple layer coating and can
comprise one or more metals, non-metals, semimetals, semiconductors
and/or alloys, compounds, composites, combinations, or blends
thereof. For example, the functional coating 42 can be a single
layer metal oxide coating, a multiple layer metal oxide coating, a
non-metal oxide coating, or a multiple layer coating.
[0029] Non-limiting examples of functional coatings 42 which can be
used with the invention are commercially available from PPG
Industries, Inc. of Pittsburgh, Pa. under the SUNGATE.RTM. and
SOLARBAN.RTM. families of coatings. Such functional coatings
typically include one or more anti-reflective coating films
comprising dielectric or anti-reflective materials, such as metal
oxides or oxides of metal alloys, which are transparent or
substantially transparent to visible light. The functional coating
42 can also include infrared reflective films having a reflective
metal, e.g., a noble metal such as gold, copper, or silver, or
combinations or alloys thereof, and can further include a primer
film or barrier film, such as titanium, as is known in the art,
located over and/or under the metal reflective layers.
[0030] The functional coating 42 can be deposited over all or at
least a portion of a major surface of at least one of the plies 18,
24. In the exemplary embodiment shown in FIG. 1, the functional
coating 42 is deposited over the inner major surface 26 of the
second ply 24. However, it is to be understood that the functional
coating 42 is not limited to this location. The functional coating
42 can be, for example, located on any of the major surfaces of the
first ply 18 or second ply 24 or on or incorporated into the
interlayer 32. The functional coating 42 can be deposited in any
conventional manner, such as but not limited to, magnetron sputter
vapor deposition (MSVD), chemical vapor deposition (CVD), spray
pyrolysis (i.e., pyrolytic deposition), atmospheric pressure CVD
(APCVD), low-pressure CVD (LPCVD), plasma-enhanced CVD (PECVD),
plasma assisted CVD (PACVD), thermal or electron-beam evaporation,
cathodic arc deposition, plasma spray deposition, and wet chemical
deposition (e.g., sol-gel). The functional coating 42 can be of any
desired type or thickness, such as a solar control coating having a
thickness of 700 .ANG. to 1000 .ANG.. The functional coating 42 can
have any number or type of infrared reflective layers, such as one
or more silver layers, e.g., 2 or more silver layers.
[0031] Although in the exemplary embodiment described above the
support 12 is a laminated article having the fluorescent material
11 located between the plies, it should be understood that the
invention is not limited to this embodiment, e.g., the fluorescent
material 11 can be located on an outer major surface of the
laminated article or, as shown in FIG. 2, the support 12 could be a
"monolithic" article 45 with the fluorescent material 11 located on
at least a portion of one or more surfaces of the monolithic
article 45. By "monolithic" is meant an article having a single
structural substrate or primary ply, e.g., a glass ply. By "primary
ply" is meant a primary support or structural member. For example,
as shown in FIG. 2, the support 12 could be formed by a single ply
46 having a first major surface 48 and a second major surface 50
with the fluorescent material 11 deposited over or carried on all
or at least a portion of at least one of the major surfaces 48, 50.
The single ply 46 can be of any material having any desired optical
characteristics, such as those described above. A protective
coating (not shown in FIG. 2), e.g., a metal or metal oxide
coating, can be deposited over the fluorescent material 11 to
protect the fluorescent material 11 from chemical or mechanical
wear. Alternatively or additionally, a functional coating 42 (not
shown in FIG. 2), such as described above, could also be deposited
over at least a portion of the one or more of the major surfaces
48, 50 (either over or under the fluorescent material) to provide
the support 12 with solar control features. An electromagnetic
radiation absorbing material 52, such as the interlayer material
described above or a similar material, could also be deposited over
all or at least a portion of one or more of the major surfaces 48,
50 of the ply 46 to reduce or eliminate electromagnetic radiation
of selected wavelengths passing through the support 12. It is also
to be understood that in this embodiment (without a radiation
absorbing material) the radiation from the radiation source 60 can
be directed at the fluorescent material from either side of the
support 12.
[0032] As described above, the support 12 can be an automotive
transparency. As used herein, the term "automotive transparency"
refers to an automotive windshield, sidelight, back light, moon
roof, sunroof, and the like. The automotive transparency can have a
visible light transmission of any desired amount, e.g., greater
than 0% to 100%, e.g., greater than 70%. For non-privacy areas, the
visible light transmission can be greater than or equal to 70%. For
privacy areas, the visible light transmission can be less than
70%.
[0033] As discussed below, the invention is not limited to use with
vehicle or automotive transparencies. For example, the monolithic
article 45 shown in FIG. 2 could be a residential or commercial
window, an advertising display, or a commercial sign configured to
display fluorescent images in a similar manner as described below.
Further, the support 12 could be a pane of a conventional
insulating glass unit. The support 12 upon which the fluorescent
material 11 is carried can be a transparent article, a translucent
article, or an opaque article.
[0034] With continuing reference to FIG. 1, the display system of
the invention, e.g., the head-up display system 10, can also
include a projection assembly 14. Although not limiting to the
invention, one exemplary projection assembly 14 is schematically
shown in FIG. 1 and includes an energy source or radiation source
60, e.g., an electromagnetic radiation source capable of emitting
radiation, e.g., electromagnetic radiation, of one or more selected
wavelengths within at least a portion of the absorption band of the
fluorescent material 11. As used herein, the term "selected
wavelength" means a single wavelength or a range of wavelengths.
However, at least a portion of the selected wavelength should be
within the absorption band of the fluorescent material 11. In one
exemplary embodiment, the radiation source 60 is a laser or laser
diode capable of emitting electromagnetic radiation of one or more
selected wavelengths, for example, in the range of 300 nm to 500
nm, such as in the range of 325 nm to 425 nm, e.g., in the range of
350 nm to 410 nm, e.g., in the range of 390 nm to 400 nm, e.g., 397
nm. However, it will be understood by one of ordinary skill in the
art that the selected wavelength of the radiation source 60 can be
selected based on the specific fluorescent material 11 utilized so
that all or at least a portion of the selected wavelength range is
at least partly within the absorption band of the fluorescent
material 11 being used. Suitable radiation sources include Model
PPM04 (LD1349) and Model PPMT25/5255 (LD1380) laser diodes
commercially available from Power Technologies, Inc. The radiation
sources can be of any desired power output, such as 5 mW to 100 mW,
e.g., 5 mW to 30 mW. Other suitable radiation sources are
commercially available from Edmund Industrial Optics and Coherent
Auburn Division. As a general rule, as the output power of the
radiation source increases, the brightness of the fluorescent image
produced also increases.
[0035] The projection assembly 14 can include a directing system 62
(e.g., a scanner) to the direct or scan radiation emitted from the
radiation source 60 toward the fluorescent material 11. The
directing system 62 can include one or more directors 64, such as a
mirror or combination of two or more mirrors, each movably mounted
on a movement device 66, such as a conventional mechanical or
electrical positioning device. For example, the director 64 can
include two mirrors, one for vertical movement and one for
horizontal movement of radiation from the radiation source 60. As
will be described in more detail below, the movement device 66 is
configured to move the director 64 to selectively direct the
radiation emitted from the radiation source 60 toward one or more
selected areas of the fluorescent material 11. A suitable director
64 is a Model 6800HP scanner commercially available from Cambridge
Technology, Inc.
[0036] A blocking device 67 can be located between the radiation
source 60 and the directing system 62. For example, the blocking
device 67 can be an electro-optical modulator, an
electro-mechanical device, or a similar device to selectively block
and unblock radiation from the radiation source 60 passing to the
directing system 62. For example, the blocking device 67 can
include a crystal which switches from being transparent to the
selected wavelength(s) to being opaque to the selected
wavelength(s) by the application of a voltage.
[0037] The radiation source 60 and/or the directing system 62
and/or blocking device 67 can be connected to a controller 68, such
as a conventional computer or electronic control device. The
controller 68 can be configured to energize the movement device 66
and to move the director 64 to direct the radiation from the
radiation source 60 toward the fluorescent material 11 to form
patterns or images, as described below. Additionally, the
controller 68 can modulate the power of the radiation source 60 to
vary the intensity of the energy beam from the radiation source. In
one embodiment, the controller 68 is configured to activate and
deactivate the blocking device 67 to block and unblock at least a
portion, e.g., all, of the radiation from the radiation source 60
passing to the director 64. If the blocking device 67 is not
present, the controller 68 can be configured to energize and
deenergize the radiation source 60 as described below. An example
of a suitable controller is a FieldGo portable computer
commercially available from Broadax Systems, Inc. Suitable control
software includes Microsoft.RTM. operating software, e.g., Windows
95.RTM.. Suitable imaging software includes "Laser Show Designer
for Windows: Professional 2.86" commercially available from
Microsoft.RTM..
[0038] The radiation source 60, directing system 62, blocking
device 67, and/or controller 68 can be in electronic communication
with a conventional power source 70, such as a battery or
electrical generator, to supply power to the components of the
head-up display system 10. Additionally, the controller 68 can be
in electronic communication with one or more vehicle operating
systems 72, such as automotive speed sensing systems, alarm
systems, global positioning systems, electronic sending or
receiving systems, and the like.
[0039] In one embodiment, the material of the interlayer 32 can be
selected to absorb at least some, for example all, of the
electromagnetic radiation from the radiation source 60 directed
toward the support 12 such that little or no electromagnetic
radiation from the radiation source 60 passes through the support
12, e.g., to the outside of the vehicle. As will be appreciated by
one of ordinary skill in the art, the amount of electromagnetic
radiation that passes through the support 12 will depend upon
several factors, such as the thickness and/or composition of the
plies 18, 24, the thickness and/or composition of the interlayer
32, the amount and/or composition of the fluorescent material 11,
and the wavelength(s) of the electromagnetic radiation emitted by
the radiation source 60. Thus, the laminated support 12 shown in
FIG. 1 and described above can provide a first portion 100 which is
transparent or substantially transparent to the electromagnetic
radiation emitted by the radiation source 60 and a second portion
102 which is non-transparent or substantially non-transparent to
the electromagnetic radiation emitted by the radiation source 60.
By "substantially transparent to the electromagnetic radiation
emitted by the radiation source 60" is meant that at least 50% of
the electromagnetic radiation emitted by the radiation source 60
(e.g., in the absorption band of the fluorescent material) passes
through, for example more than 70%, such as more than 80%, e.g., in
the range of 50% to 100%. By "substantially non-transparent to the
electromagnetic radiation emitted by the radiation source 60" is
meant that less than 50% of the electromagnetic radiation emitted
by the radiation source 60 passes through, for example less than
35%, such as less than 20%, e.g., in the range of 50% to 0%. In
addition to the interlayer 32, utilizing a colored or tinted, i.e.,
non-clear, material for the second ply 24, will also absorb some of
the electromagnetic radiation emitted by the radiation source 60
directed toward the support 12.
[0040] An exemplary method of practicing the invention will now be
described with particular reference to the exemplary head-up
display having the laminated support 12 shown in FIG. 1. The
controller 68 energizes the radiation source 60 to emit a beam 74
of electromagnetic radiation of one or more selected wavelengths
toward the director 64. Assuming the blocking device 67 is in a
deenergized or "open" mode, at least a portion, e.g., all, of the
emitted radiation passes through the blocking device 67 and onto
the director 64. The director 64 redirects this energy beam 74
toward the fluorescent material 11 located on the support 12. The
fluorescent material 11 absorbs at least a portion of the
electromagnetic radiation and then fluoresces, i.e., emits energy
76, such as energy in the visible region of the electromagnetic
spectrum which can be seen by an occupant 78 of the vehicle. The
occupant 78 can be the vehicle driver or one or more of the
passengers.
[0041] The controller 68 can direct the movement device 66 to point
the director 64 to different areas of the fluorescent material 11
to cause these selected areas of the fluorescent material 11 to
fluoresce to form an image visible to the occupant 78. The
controller 68 can vary the output, e.g., the power or beam
intensity, of the radiation source 60 to cause different areas of
the fluorescent material 11 to fluoresce at different levels of
brightness. For example, in one exemplary embodiment the director
64 can raster the direction of the radiation beam 74 along a
portion or all of the fluorescent material 11. By "raster", is
meant to form a scan pattern, e.g., by scanning an area from side
to side in lines from top to bottom or bottom to top. As the scan
pattern is formed, the controller 68 can selectively energize and
deenergize, i.e., open and close, the blocking device 67 to form
adjacent fluorescent and non-fluorescent areas on the support 12 to
thereby form one or more fluorescent images discernable by the
driver. In an alternative embodiment in which no blocking device 67
is present, the controller 68 could energize and deenergize the
radiation source 60 to form the fluorescent images.
[0042] An exemplary fluorescent image 80 in the form of the letter
"P" formed on a portion 82 of the support 12 is depicted by the
shaded area in FIG. 3. In one exemplary method of forming this
image 80, the director 64 is moved in first and second directions,
e.g., from side to side (as depicted by directions L and R), and is
displaced in a substantially perpendicular direction, e.g., up and
down (as depicted by directions U and D), to form a scan pattern or
a plurality of scan paths 84a to 84g. For purposes of the present
explanation only, the individual scan paths 84a to 84g are depicted
as being separated by dashed lines in FIG. 3. However, it will be
understood that these dashed lines are simply for explanation
purposes only and would not be visible during actual operation. The
width (W) of the scan paths 84a to 84g can correspond to a width of
the beam 74. Adjacent scan paths can be overlapping, i.e. the
perpendicular displacement of the director 64 (in the U or D
directions) can be less than the width of the beam 74. On the other
hand, the perpendicular displacement of the director 64 can be
greater than the width of the beam 74 so that a gap is formed
between adjacent scan paths (not shown).
[0043] In one exemplary method of forming the image 80, the
director 64 can be traversed from left to right with respect to
FIG. 3 along the uppermost scan path 84a with the blocking device
67 energized, i.e., closed. When the director 64 reaches a position
equivalent to position 86, i.e., when the director 64 is pointing
to position 86, the blocking device 67 can be deenergized while the
director 64 continues to traverse to the right (direction R) so
that the region of the uppermost scan path 84a from position 86 to
position 88 fluoresces. At position 88, the blocking device 67 can
be energized (closed) for the remainder of the scan path 84a (i.e.,
until the director 64 reaches the end of the scan path 84a). The
director 64 can then be displaced in direction D to the next scan
path 84b and moved in direction L along the scan path 84b to
position 88 where the blocking device 67 is again deenergized
(opened) from position 88 to position 90. At position 90, the
blocking device 67 is energized (closed) until position 92 when the
blocking device 67 is again deenergized (open) from position 92 to
position 86. At position 86, the blocking device 67 is energized
(closed) for the remainder of the scan path 84b, at which time the
director 64 is again displaced in direction D to the next scan path
84c. In this manner, the fluorescent image 80 can be formed. While
the formation of only a single letter is described above, it will
be understood that adjacent letters, words, sentences, numbers,
symbols, or images could be formed in a similar manner.
[0044] It is also to be understood that the image forming method of
the invention is not limited to the above-described exemplary
rastering embodiment. For example, while in the above-described
method the director 64 is alternately moved laterally from left to
right and right to left across the fluorescent material 11 while
energizing and deenergizing the blocking device 67 to form the
image 80, the director 64 could alternatively be laterally moved in
only one direction while forming the image 80, e.g., always to the
right or always to the left while forming the scan pattern in
similar manner to the movement of an electron beam in a
conventional cathode ray tube image system. For example, the
director 64 could start on the upper left scan path 84a and scan to
the right while energizing and deenergizing the blocking device 67.
At the end of the scan path 84a, the blocking device 67 can be
energized (closed), the director moved to the left and down to the
left side of the next scan path 84b, and then the director 64 moved
to the right along the second scan path 84b while energizing and
deenergizing the blocking device 67. Further, rather than starting
at the top of the scan pattern and moving downwardly, the image 80
could be formed by starting at the bottom of the scan pattern and
moving the director 64 to direct the radiation beam 74 upwardly.
Additionally, rather than moving the director 64 across the entire
field of the fluorescent material 11, the director 64 could be used
to "paint" an image, i.e., the director 64 could be moved or
directed by the controller 68 to only trace over or within the
actual area of the pattern or image to be formed. For example, to
form the letter "P", the director 64 would point, e.g., direct the
beam 74, only to the area within the confines of the letter "P"
rather than sweeping the director 64 over the area outside of the
area forming the fluorescent letter "P" which is to remain
non-fluorescent. As will be appreciated by one of ordinary skill in
the art, the invention is not limited to the type of rastering or
scanning process used to form the image 80. For example, rather
than the horizontal scanning methods described above, the scan
pattern can be formed by using vertical scan paths with lateral
displacement at the end of the vertical scan path. Diagonal scan
paths could even be used, if desired.
[0045] Alternatively, in an embodiment without the blocking device
67, the radiation source 60 could be energized and deenergized
during formation of the scan pattern on the fluorescent material 11
to form a desired image.
[0046] As discussed above, for a vehicle head-up display the
controller 68 can be in electronic communication with various
on-board vehicle systems 72 to utilize the projection assembly 14
to form desired fluorescent images on the support 12. Examples of
such images can include vehicle speed, vehicle system indicator
lights (such as oil, generator, tachometer, etc.), navigational
information from a GPS system, and a vehicle security system. For
example, the controller 68 can be designed such that should the
vehicle security system be activated, the radiation source 60,
blocking device 67, and director 64 are controlled to fluoresce at
least a portion of the fluorescent material 11 on the support 12
and/or to form particular phrases which would be readable by those
outside the vehicle, such as "help" or "please notify police", etc.
As a further example, the controller 68 can be in electronic
communication, e.g., by radio wave, with a hand-held or pocket
device, such as a key chain having a small radio wave transmitter,
so that when the pocket device is activated, the horn sounds and/or
the controller 68 activates the radiation source 60, blocking
device 67 and directing system 62 to cause at least a portion of
the fluorescent material 11 to fluoresce. This would be
particularly useful in locating the vehicle in a crowded parking
lot if the driver could not remember exactly where he parked the
vehicle. In an additional example, images from video cameras
operating in any wavelength range, such as visible or infrared,
could be projected onto the support 12 carrying the fluorescent
material 11 to form an image. In this manner, infrared cameras
mounted on the vehicle could aid vision at night or under adverse
weather conditions. Cameras, e.g., mounted on vehicles, could also
supplement vision available in the conventional fashion through
windows and in mirrors.
[0047] As will be appreciated by one of ordinary skill in the art,
more than one light emitting material, e.g., fluorescent material
11, can be carried on the support 12. The different fluorescent
materials can be selected to fluoresce at different wavelengths or
at different ranges of wavelengths and, hence, to fluoresce at
different visible colors. A plurality of projection assemblies
having different radiation sources 60 (the radiation sources 60
having respective output wavelengths within the absorption bands of
the respective fluorescent materials) with respective directing
systems 62 could be positioned in the vehicle so that different
types of data can be displayed with different fluoresced colors. In
FIG. 1, an optional second projection assembly 14' is shown in
dotted lines. For example, a first radiation source and fluorescent
material combination can be utilized to display a first type of
information, such as vehicle speed, by forming images of a first
color, e.g., blue fluorescent images, on the support. This means
that at least a portion of the fluorescent material on the support
absorbs electromagnetic radiation in the wavelength or wavelength
range emitted by the first radiation source and fluoresces at a
selected visible wavelength or range in the blue region of the
visible electromagnetic spectrum. Another source of information,
such as vehicle status indicators, can be displayed using a second
projection assembly having a second radiation source that is
configured to fluoresce a second fluorescent material present on
the support at a selected wavelength or range in a second color
region, e.g., the yellow region, of the visible electromagnetic
spectrum. If different fluorescent materials are deposited on the
support, it would also be possible utilizing different laser
devices to form colored images by simultaneously irradiating the
fluorescent materials such that the fluoresced light from the
different fluorescent materials combine to form a selected color.
In the example described immediately above, the two fluorescent
materials can be simultaneously irradiated such that the resultant
blue and yellow fluoresced images combine to form a green colored
image.
[0048] Alternatively, a single fluorescent material 11 that
fluoresces over a range of wavelengths dependent upon the
wavelength(s) of the absorbed radiation can be provided on the
support 12. For example, the fluorescent material 11 can fluoresce
at one or more first fluorescent wavelength(s) (e.g., in the blue
region of the electromagnetic spectrum) when irradiated by
electromagnetic energy of one or more first irradiation
wavelength(s) and fluoresce at a second fluorescent wavelength(s)
(e.g., in the yellow region of the electromagnetic spectrum) when
irradiated by electromagnetic energy of one or more second
irradiation wavelength(s). In a still further embodiment, the
plurality of radiation sources 60 described above can be
substituted with a single radiation source capable of selectively
emitting electromagnetic energy of two or more desired wavelengths
or ranges or wavelengths such that the single radiation source is
capable of providing electromagnetic energy in the absorption
band(s) of the one or more fluorescent materials 11 to form
separate images of differing color and/or an image of a desired
(combined) color as described above.
[0049] An alternative projection assembly 110 of the invention is
shown in FIG. 4. This projection assembly 110 is similar to the
projection assembly 14 shown in FIG. 1 but the radiation source 60
is directly and movably connected to the movement device 66 so that
the radiation source 60 can be moved and simultaneously energized
and deenergized to form fluorescent images on the support 12 in
similar manner as described above.
[0050] For use in a conventional automobile, the projection
assemblies described above can be located in or under the vehicle
dashboard, with the dashboard having a slot or opening of
sufficient size to permit the beam 74 to pass through. However, the
invention is not limited to placement of the projection assembly at
this location. For example, if the display system 10 of the
invention were incorporated into a side window, rear window, moon
roof, etc., the projection assembly could be placed at any desired
location in the vehicle to allow operation of the display device 10
as described above. Also, the controller 68 can be configured to
vary the application of the energy from the radiation source 60 to
modify the resultant fluorescent image to adjust for variations in
curvature of the support 12.
[0051] While the above discussion was directed primarily to
utilization of the invention in a vehicle head-up display, the
invention is not limited to this use. The invention could be
practiced in a brood range of information display or entertainment
applications. For example, a support 12 as described above (whether
a laminated support as shown in FIG. 1 or a monolithic support as
shown in FIG. 2) could be used in a commercial location, such as a
department store, grocery store, retail shop, etc., to display
information regarding pricing information, upcoming sales, current
specials, and the like. Unlike prior systems, the present invention
would permit quick and easy changes and modifications to the
displayed information utilizing the controller (e.g., a personal
computer).
[0052] One exemplary use of the invention in the entertainment
field would be in image displays for entertainment events, such as
sporting events (e.g., football, baseball, hockey, basketball, and
the like) or social events (nightclubs, bars, displays for shopping
malls, and the like). For example, the invention could be used with
a sound system at a nightclub to display images related to
particular songs being played.
[0053] The general concept of the invention will be described
further with reference to the following Examples. However, it is to
be understood that the following Examples are merely illustrative
of the general concepts of the invention and are not intended to be
limiting.
EXAMPLE 1
[0054] This example demonstrates forming fluorescent images
utilizing a laser and a laminated support having fluorescent
material located between the plies of the laminate.
[0055] A laminated article was formed using a 10 cm by 10 cm square
piece of clear float glass 2 mm thick as a first ply and a 10 mm by
10 mm by 2 mm thick piece of SOLEX.RTM. glass commercially
available from PPG Industries, Inc. of Pittsburgh, Pa. as a second
ply. SOLEX.RTM. glass has a green tint. To incorporate fluorescent
material into the laminated article, 0.025 g of Uvitex OB
fluorescent material commercially available from Ciba Specialty
Chemicals Corporation was dissolved in 50 ml of methanol. This
solution was then applied onto a glass blank by dipping a surface
of the blank into the solution. The solution remaining on the glass
blank was then allowed to dry for five minutes under a heat lamp to
form a dried layer of fluorescent material on the blank. A major
surface of the 10 cm by 10 cm clear glass ply described above was
then pressed against the dried fluorescent material on the glass
blank to adhere at least some of the dried fluorescent material
onto the major surface of the clear glass ply. The SOLEX.RTM. glass
ply and the clear glass ply with the adhered fluorescent material
were then laminated together utilizing Grade B 180 SL polyvinyl
butyral commercially available from E.I. duPont de Nemours
Corporation to form an interlayer having a thickness of 0.5 mm. The
clear glass ply was positioned such that the fluorescent material
was on the interior surface of the clear glass ply, i.e., on the
side of the clear glass ply facing the interlayer. The lamination
process included a vacuum stage and an autoclave stage. During the
vacuum stage, the assembled parts of the article were subjected to
a vacuum from a mechanical pump for seven minutes at room
temperature and then for eighteen minutes at 255.degree. F.
(124.degree. C.). During the autoclave stage, an automatic process
controlled the pressure and temperature. The pressure was raised
from atmospheric to 50 psi gage (3.5 kg/sq. cm) in ten minutes,
held a 50 psi gage (3.5 kg/sq. cm) for ten minutes, raised to 200
psi gage (14 kg/sq. cm) in five minutes, held at 200 psi gage (14
kg/sq. cm) for thirty minutes, and decreased to atmospheric
pressure in five minutes. The temperature was raised to 285.degree.
F. (140.degree. C.) in ten minutes, held at 285.degree. F.
(140.degree. C.) for thirty-five minutes, and allowed to cool for
fifteen minutes. The laminated article was positioned on a support
and an energy beam from a laser commercially available from
Spectra-Physics and having a rated output of 7.5 mW at 350 nm was
directed to the clear glass ply side of the laminated article. The
absorption band for the fluorescent material, which has its peak at
375 nm, overlapped the wavelength of the laser output. The
electromagnetic radiation from the laser caused the fluorescent
material to fluoresce and produce a strong, visible blue dot where
the laser beam was directed onto the clear glass ply side of the
laminated article. The laser beam, reflected by a hand-held mirror,
was moved across the clear glass ply side to cause the fluorescent
material in the path of the laser beam to fluoresce. The laser beam
was then directed to the SOLEX.RTM. glass ply side of the article
and no fluorescence was detected. This indicates that the
electromagnetic beam from the laser was not transmitted through the
SOLEX.RTM. glass ply and/or polyvinyl butyral interlayer. Thus, the
laser beam passes through the clear glass ply side, but not through
the polyvinyl butyral and SOLEX.RTM. glass ply side of the
article.
EXAMPLE 2
[0056] The laminated article from Example 1 above was used with a
different projection system than described above.
[0057] The projection system used in this Example utilized a model
LD1349 laser diode commercially available from Power Technology,
Inc. and had a rated output of 5 mW at 395 nm to 397 nm. This
wavelength range is also within the absorption band of the Ciba
Specialty Chemicals Corporation fluorescent material incorporated
into the laminated article. Again, the laser beam was directed to
the clear glass ply side of the article and fluorescence was
observed yielding a fluorescent blue light along the path of the
laser beam.
[0058] FIG. 5 is a graph of percent transmittance vs. wavelength
for a 2.1 mm thick piece of clear float glass (curve 112) and also
for the laminated article (curve 114) described above in Example 1.
As shown in FIG. 5, for these particular materials there is a
"transmittance gap" 116 between the two curves. For example, energy
at a wavelength of 370 nm has a transmittance of 70% through the
clear glass but has a transmittance of 0% through the laminated
article itself. Thus, if a fluorescent material having an
absorption band which includes 370 nm is used in the laminated
article, an energy beam of 370 nm can be directed through the clear
glass side of the laminated article to cause fluorescence but will
not pass through the rest of the laminated article.
[0059] While some exemplary embodiments and uses of the present
invention have been described above, it will be readily appreciated
by those skilled in the art that modifications can be made to the
invention without departing from the concepts disclosed in the
foregoing description. For example, although the invention was
described above with particular use as a head-up display for a
vehicle, the display system of the invention could be used in
non-vehicular applications, such as the formation of images or
information displays on non-transparent surfaces in vehicles or
elsewhere, such as walls, ceilings, or opaque screens. This
information could include displays of advertisements, entertainment
(such as light displays), or decorative patterns which could be
changed as desired by an operator. Moreover, although the
embodiments described above primarily utilized one or more
fluorescent materials, it is to be understood that other types of
light emitting materials, such as but not limited to phosphorescent
material(s) could be used in lieu of or in addition to the
fluorescent material(s). Accordingly, the particular embodiments
described in detail herein are illustrative only and are not
limiting to the scope of the invention, which is to be given the
full breadth of the appended claims and any and all equivalents
thereof.
* * * * *