U.S. patent application number 13/314249 was filed with the patent office on 2013-06-13 for windshield with fluorescent electrowetting display.
This patent application is currently assigned to DELPHI TECHNOLOGIES, INC.. The applicant listed for this patent is FREDERICK F. KUHLMAN, DAVID K. LAMBERT, DWADASI H. R. SARMA, KRIS R. STARK. Invention is credited to FREDERICK F. KUHLMAN, DAVID K. LAMBERT, DWADASI H. R. SARMA, KRIS R. STARK.
Application Number | 20130148187 13/314249 |
Document ID | / |
Family ID | 47257542 |
Filed Date | 2013-06-13 |
United States Patent
Application |
20130148187 |
Kind Code |
A1 |
KUHLMAN; FREDERICK F. ; et
al. |
June 13, 2013 |
WINDSHIELD WITH FLUORESCENT ELECTROWETTING DISPLAY
Abstract
A windshield assembly that includes a fluorescent electrowetting
cell and an opaque electrowetting cell overlying a windshield and
configured so the opaque electrowetting cell cooperates with the
fluorescent electrowetting cell to contrast an image displayed by
the fluorescent electrowetting cell with respect to a field of view
beyond the windshield assembly. The ability to contrast the image
makes the image easier to see when bright sunlight is present.
Inventors: |
KUHLMAN; FREDERICK F.;
(KOKOMO, IN) ; LAMBERT; DAVID K.; (STERLING
HEIGHTS, MI) ; SARMA; DWADASI H. R.; (KOKOMO, IN)
; STARK; KRIS R.; (CARMEL, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KUHLMAN; FREDERICK F.
LAMBERT; DAVID K.
SARMA; DWADASI H. R.
STARK; KRIS R. |
KOKOMO
STERLING HEIGHTS
KOKOMO
CARMEL |
IN
MI
IN
IN |
US
US
US
US |
|
|
Assignee: |
DELPHI TECHNOLOGIES, INC.
TROY
MI
|
Family ID: |
47257542 |
Appl. No.: |
13/314249 |
Filed: |
December 8, 2011 |
Current U.S.
Class: |
359/290 |
Current CPC
Class: |
G02B 27/01 20130101;
G02B 26/005 20130101; G02B 2027/0118 20130101 |
Class at
Publication: |
359/290 |
International
Class: |
G02B 26/00 20060101
G02B026/00 |
Claims
1. A windshield assembly configured for installation onto a
vehicle, said assembly comprising: a windshield; a fluorescent
electrowetting cell overlying a portion of the windshield, wherein
the fluorescent electrowetting cell is operable to a fluorescent
state where the fluorescent electrowetting cell fluoresces when
illuminated with suitable light, and operable to a transparent
state where most light passes through the fluorescent
electrowetting cell; and an opaque electrowetting cell arranged
proximate to the fluorescent electrowetting cell, wherein the
opaque electrowetting cell is operable to an opaque state where
most light is blocked from passing through the opaque
electrowetting cell, and a clear state where most light passes
through the opaque electrowetting cell, wherein the portion is
substantially transparent when the fluorescent electrowetting cell
is operated to the transparent state and the opaque electrowetting
cell is operated to the clear state, and the opaque electrowetting
cell cooperates with the fluorescent electrowetting cell to
contrast an image displayed by the fluorescent electrowetting cell
with respect to a field of view beyond the assembly.
2. The assembly in accordance with claim 1, wherein the fluorescent
electrowetting cell is disposed in a first layer overlying the
portion, and the opaque electrowetting cell is disposed in a second
layer between the first layer and the windshield.
3. The assembly in accordance with claim 2, wherein the first layer
comprises an array of fluorescent electrowetting cells, and the
second layer comprises an array of opaque electrowetting cells
underlying the array of fluorescent electrowetting cells.
4. The assembly in accordance with claim 3, wherein the second
layer is operated to surround the image displayed by the first
layer with an opaque area.
5. The assembly in accordance with claim 2, wherein the first layer
comprises one or more fluorescent electrowetting cells configured
to display one or more images characterized as having a
predetermined shape, and the second layer comprises one or more
opaque electrowetting cells arranged adjacent to the one or more
fluorescent electrowetting cells.
6. The assembly in accordance with claim 5, wherein the one or more
opaque electrowetting cells are a plurality of opaque
electrowetting cells configured to surround at least one of the one
or more images displayed by the one or more fluorescent
electrowetting cells with an opaque area.
7. The assembly in accordance with claim 1, wherein the fluorescent
electrowetting cell and the opaque electrowetting cell are disposed
in a common layer overlying the portion.
8. The assembly in accordance with claim 7, wherein the common
layer comprises an array of electrowetting cells that includes
fluorescent electrowetting cells and opaque electrowetting
cells.
9. The assembly in accordance with claim 8, wherein the pattern is
characterized as a checkerboard pattern of alternating fluorescent
electrowetting cells and opaque electrowetting cells.
10. The assembly in accordance with claim 7, wherein the common
layer comprises one or more fluorescent electrowetting cells
configured to display one or more images characterized as having a
predetermined shape, and the common layer further comprises one or
more opaque electrowetting cells arranged adjacent to the one or
more fluorescent electrowetting cells.
11. The assembly in accordance with claim 10, wherein the one or
more opaque electrowetting cells are a plurality of opaque
electrowetting cells arranged to surround at least one of the one
or more images.
12. The assembly in accordance with claim 1, wherein the assembly
further comprises a controller configured to operate the
fluorescent electrowetting cell and the opaque electrowetting
cell.
13. The assembly in accordance with claim 1, wherein the assembly
further comprises a light source configured to illuminate the
fluorescent electrowetting cell with suitable light.
Description
TECHNICAL FIELD OF INVENTION
[0001] This disclosure generally relates to a windshield assembly
equipped with fluorescent electrowetting type display, and more
particularly relates to a windshield assembly that includes a
fluorescent electrowetting layer and an opaque electrowetting layer
arranged to contrast an image displayed by a fluorescent
electrowetting cell with respect to a field of view beyond the
windshield assembly.
BACKGROUND OF INVENTION
[0002] Vehicle manufacturers desire windshield assemblies able to
display information anywhere on the windshield. By displaying
information on the windshield, an operator of a vehicle may be able
to better concentrate on a field of view of the area forward of the
vehicle, as compared to when similar information is displayed on a
vehicle instrument panel positioned below the field of view.
Various arrangements of fluorescent films and transparent displays
have been proposed, but such displays generally aren't bright
enough to be useful in bright sunlight.
SUMMARY OF THE INVENTION
[0003] In accordance with one embodiment, a windshield assembly
configured for installation onto a vehicle is provided. The
assembly includes a windshield, a fluorescent electrowetting cell,
and an opaque electrowetting cell. The fluorescent electrowetting
cell overlies a portion of the windshield. The fluorescent
electrowetting cell is operable to a fluorescent state where the
fluorescent electrowetting cell fluoresces when illuminated with
suitable light, and operable to a transparent state where most
light passes through the fluorescent electrowetting cell. The
opaque electrowetting cell is arranged proximate to the fluorescent
electrowetting cell. The opaque electrowetting cell is operable to
an opaque state where most light is blocked from passing through
the opaque electrowetting cell, and a clear state where most light
passes through the opaque electrowetting cell. The portion is
substantially transparent when the fluorescent electrowetting cell
is operated to the transparent state and the opaque electrowetting
cell is operated to the clear state. The opaque electrowetting cell
cooperates with the fluorescent electrowetting cell to contrast an
image displayed by the fluorescent electrowetting cell with respect
to a field of view beyond the assembly.
[0004] Further features and advantages will appear more clearly on
a reading of the following detailed description of the preferred
embodiment, which is given by way of non-limiting example only and
with reference to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0005] The present invention will now be described, by way of
example with reference to the accompanying drawings, in which:
[0006] FIG. 1 is a side view of a vehicle equipped with a
windshield assembly in accordance with an embodiment;
[0007] FIG. 2 is an interior view of the vehicle equipped with the
windshield assembly of FIG. 1 in accordance with an embodiment;
[0008] FIG. 3 is side sectional view of the windshield assembly of
FIG. 1 in accordance with an embodiment;
[0009] FIG. 4 is a front view of a portion of the windshield
assembly of FIG. 1 in accordance with an embodiment;
[0010] FIG. 5 is a front view of a portion of the windshield
assembly of FIG. 1 in accordance with an embodiment;
[0011] FIG. 6 is a side sectional view of the windshield assembly
of FIG. 1 in accordance with an embodiment; and
[0012] FIG. 7 is a front view of a portion of the windshield
assembly of FIG. 1 in accordance with an embodiment.
DETAILED DESCRIPTION
[0013] FIG. 1 illustrates a non-limiting example of a windshield
assembly 10, hereafter often assembly 10, installed in a vehicle
12. In general, the assembly 10 displays information such as
graphical symbols or alpha-numeric characters on the assembly 10 so
that an operator 14 of the vehicle 12 does not need to avert
his/her eyes from a field of view 16 forward of the vehicle 12 to
perceive displayed information. In general, the assembly 10 may be
operated to a transparent or clear state so that the operator 14 is
able to see clearly through the entire area of the assembly 10, or
images may be superimposed into the field of view 16. The images
are preferably formed by fluorescent material that may be
illuminated to fluoresce by the sun 18 and/or ultraviolet (UV)
light sources 20 (FIG. 2), such as a UV light emitting diode. As
will be described in more detail below, the assembly 10 is
generally configured to overcome problems associated with viewing a
translucent fluorescent image in bright sunlight by fully
surrounding or partially surrounding the fluorescent image being
displayed with a contrasting edging border or surrounding area. For
example, the fluorescent image may be surrounded by an opaque black
area so the fluorescent image visually stands out when viewed
against a blue sky background, or viewed against other bright
backgrounds such as bright lights from roadway lighting,
illuminated signs, or headlights from other oncoming vehicles.
[0014] FIG. 2 illustrates an interior view of the vehicle 12
equipped with a non-limiting example of the assembly 10. The
assembly 10 may include a windshield 22 formed of, for example,
tempered/safety glass that is commonly used for automobile
windshields. Alternatively, the windshield 22 may be formed of a
polymeric material such as polycarbonate that is sometimes used for
military aircraft canopies or protective windows in off-road
construction equipment.
[0015] The assembly 10 may include one or more fluorescent
electrowetting cells 24 overlying one or more portions 26, 26A, 26B
of the windshield 22. In general, the fluorescent electrowetting
cell 24 is operable to a fluorescent state where the fluorescent
electrowetting cell 24 fluoresces when illuminated with suitable
light, for example sunlight from the sun 18 or UV light from the UV
light source 20. Alternatively, suitable light may be projected
into the edge of the assembly so that the light propagates via
internal reflections throughout the windshield 22. The fluorescent
electrowetting cell 24 is also generally operable to a transparent
state where most light passes through the fluorescent
electrowetting cell 24. As used herein, `most light` means that the
fluorescent electrowetting cell 24 is substantially transparent,
and for example having a visible light transmissivity factor of
0.75 or greater.
[0016] U.S. Pat. No. 7,872,790 to Steckl et al. issued Jan. 18,
2011 describes a suitable electrowetting cell construction, the
entire contents of which are hereby incorporated by reference
herein. A paper entitled Demonstration of Fluorescent RGB
Electrowetting Devices for Light Wave Coupling Displays by J.
Heikenfeld et al. published 2004 shows an example of fluorescent
electrowetting cells on a transparent substrate, the entire
contents of which are hereby incorporated by reference herein.
Preferably, the `oil` layer in the fluorescent electrowetting cell
24 is translucent so that the sun 18 can be used to back-light
images displayed by the fluorescent electrowetting cell 24. When
the fluorescent electrowetting cell 24 is in the fluorescent state,
a visible light transmissivity of 0.50 to 0.85 is preferable, but
other values may be suitable. It should be appreciated that it is
preferable for the light transmissivity value during the
transparent state to be higher than the light transmissivity during
the fluorescent state.
[0017] The assembly 10 may include one or more opaque
electrowetting cells 28 arranged proximate to the fluorescent
electrowetting cell 24. As used herein, proximate to the
fluorescent electrowetting cell 24 includes beside, underlying or
overlying, and adjacent to the fluorescent electrowetting cell 24
so that the opaque electrowetting cells 28 help to make an image
displayed by the fluorescent electrowetting cells 24 easier to read
or identify. In general, the opaque electrowetting cell 28 is
operable to an opaque state where most light is blocked from
passing through the opaque electrowetting cell 28. Preferably, the
`oil` layer in the opaque electrowetting cell 28 is black in color.
As used herein, when most light is blocked by the opaque
electrowetting cell 28, it means that the opaque electrowetting
cell 28 preferably has a visible light transmissivity factor of
0.50 or less. The opaque electrowetting cell 28 is also operable to
a clear state where most light passes through the opaque
electrowetting cell. A suitable visible light transmissivity factor
is 0.75 or greater.
[0018] Accordingly, the portions 26, 26A, 26B are substantially
transparent when the fluorescent electrowetting cell 24 is operated
to the transparent state and the opaque electrowetting cell 28 is
operated to the clear state. For example, even when the fluorescent
electrowetting cell 24 and the opaque electrowetting cell 28 are
configured in an overlying arrangement so the same light passes
through both cells, it is preferable to have a total light
transmissivity greater than 0.75. Furthermore, as will be described
in more detail below, the opaque electrowetting cell 28 cooperates
with the fluorescent electrowetting cell 24 to contrast an image
displayed by the fluorescent electrowetting cell 24 with respect to
a field of view 16 that is beyond the assembly 10, in other words
outside of the vehicle 12. It should be appreciated that the light
transmissivity factor of the opaque electrowetting cell 28 and the
fluorescent electrowetting cell 24, when operated into their
various states, can be adjusted by selecting various materials for
the cells, and by operating the cells part way between their end
states (e.g. fully transparent or clear, fully fluorescent or
opaque). It should also be appreciated that a visor region 34
covering the entire width of the assembly 10 can be equipped with
opaque electrowetting cells operable to provide a sun-shade or
sun-visor function to the operator 14, or possibly an area bigger
than that covered by the fluorescent electrowetting cells 24.
[0019] FIG. 3 illustrates a cross section side view of a
non-limiting embodiment of the assembly 10 where the fluorescent
electrowetting cell 24 is disposed in a first layer 30 overlying
the portion 26 (or 26A or 26B), and the opaque electrowetting cell
28 is disposed in a second layer 32 between the first layer 30 and
the windshield 22. It should be understood that the first layer 30
may include a single fluorescent electrowetting cell 24 having a
particular predetermined shape, a cluster of fluorescent
electrowetting cells 24 arranged to operate together to display a
predetermined shape, or an array of fluorescent electrowetting
cells 24 each individually operable to form a reconfigurable
pixelated type display capable of displaying variety of shapes.
Similarly, the opaque electrowetting cells underlying the
fluorescent electrowetting cell may be configured in any of these
ways. It is recognized that the assembly 10 could have an
alternative configuration where the first layer 30 is between the
second layer 32 and the windshield 22.
[0020] FIG. 4 illustrates a front view of a non-limiting example of
an image 36 in the form of an alpha-numeric character `T` being
displayed on the portion 26A for the case where both the first
layer 30 and the second layer 32 are arrays of cells and each cell
in each layer is aligned position and size wise with the
underlying/overlying cell. In this example, a fluorescent area 38
is defined by operating a number of the fluorescent electrowetting
cells within the fluorescent area 38 to the fluorescent state, and
the remaining fluorescent electrowetting cells outside the
fluorescent area 38 are operated to the transparent state.
Similarly, an opaque area 40 outlining the fluorescent area 38 may
be defined by operating opaque electrowetting cells within the
opaque area 40 to an opaque state, and all other opaque
electrowetting cells outside of the opaque area 40, including those
underlying the fluorescent area 38, are operated to clear state. If
multiple alpha-numeric characters are desired, the opaque area may
individually surround each alpha-numeric character in the same
manner as suggested in FIG. 4, or the opaque area 40 may encompass
all of the alpha-numeric characters so light from the sun 18 or
other sources is not viewable in the spaces between adjacent
alpha-numeric characters.
[0021] FIG. 5 illustrates a front view of a non-limiting example of
an image 42 displayed on the portion 26B. In this example, the
first layer comprises one or more fluorescent electrowetting cells
24 configured to display predetermined shape corresponding to an
automobile, and the second layer comprises one or more opaque
electrowetting cells 28 arranged adjacent to surround the
fluorescent electrowetting cells 24.
[0022] FIG. 6 illustrates a cross section side view of a
non-limiting embodiment of the assembly 10 where the fluorescent
electrowetting cell 24 and the opaque electrowetting cell 28 are
disposed in a common layer 44 overlying the portion 26. FIG. 7
illustrates a front view of FIG. 6 where common layer includes an
array of electrowetting cells that includes fluorescent
electrowetting cells 24 and opaque electrowetting cells 28. The
pattern may be a checkerboard pattern of alternating fluorescent
electrowetting cells and opaque electrowetting cells as
illustrated, however other shapes and patterns of cells will be
readily apparent to those skilled in the art. This arrangement is
advantageous over the arrangement shown in FIGS. 3 and 4 because
the single common layer 44 is less costly to apply to the
windshield 22 when compared to the first layer 30 and the second
layer 32. Furthermore, transparent/clear state transmissivity will
typically be higher with this common layer arrangement since there
are fewer layers for light to pass through.
[0023] In another embodiment, the common layer 44 may include one
or more fluorescent electrowetting cells configured to display one
or more images characterized as having a predetermined shape, and
the common layer further comprises one or more opaque
electrowetting cells arranged adjacent to the one or more
fluorescent electrowetting cells. Such an arrangement would be
useful to display the image 42 shown in FIG. 5; however it is
recognized that the common layer configuration would not be as
suitable for providing the visor function as is the case with other
configurations.
[0024] Referring again to FIG. 2, the assembly 10 may include a
controller 46 configured to operate the fluorescent electrowetting
cell 24 and the opaque electrowetting cell 28. The controller may
be electrically connected to the fluorescent electrowetting cell 24
and the opaque electrowetting cell 28 by a wire 47, or a plurality
of wires, or other interconnecting means known to those in the art
such as optical fiber. The controller 46 may include a processor
(not shown) such as a microprocessor or other control circuitry as
should be evident to those in the art. The controller 46 may
include memory, including non-volatile memory, such as electrically
erasable programmable read-only memory (EEPROM) for storing one or
more routines, thresholds and captured data. The one or more
routines may be executed by the processor to perform steps for
determining if signals received by the controller 46 for operating
the assembly 10 as described herein. The controller 46 may include
pushbuttons 48 or the like so the operator 14 is able to configure
what information is displayed on the portions 26, 26A, 26B of the
assembly 10.
[0025] Accordingly, a windshield assembly 10 is provided. Combining
the fluorescent electrowetting cells 24 and the opaque
electrowetting cells 28 into the assembly 10 provides for a display
that can be better viewed when brightly lit backgrounds are present
as compared to display that only has fluorescent electrowetting
cells.
[0026] While this invention has been described in terms of the
preferred embodiments thereof, it is not intended to be so limited,
but rather only to the extent set forth in the claims that
follow.
* * * * *