U.S. patent application number 12/488947 was filed with the patent office on 2010-12-23 for vehicle rearview mirror with spotter mirror.
Invention is credited to Randall S. Braun, David J. Cammenga, Michael L. McLarty, Brian J. Steenwyk.
Application Number | 20100321757 12/488947 |
Document ID | / |
Family ID | 43354108 |
Filed Date | 2010-12-23 |
United States Patent
Application |
20100321757 |
Kind Code |
A1 |
Cammenga; David J. ; et
al. |
December 23, 2010 |
VEHICLE REARVIEW MIRROR WITH SPOTTER MIRROR
Abstract
A mirror element comprising a front element, a rear element,
electrochromic material therebetween, and a spotter optic located
at the rear surface of the front element. At least a portion of the
spotter optic has a first radius of curvature and at least a
portion of the front surface of the front element has a greater
second radius of curvature. A line perpendicular to the front
surface extends through both the electrochromic material and the
spotter optic. A first electrode coating and a second electrode
coating are activated to activate the electrochromic material in
order to dim a reflection off of the mirror element. A reflective
coating of the spotter optic can form a portion of the first
electrode coating. The first electrode coating and the reflective
coating can overlap.
Inventors: |
Cammenga; David J.;
(Zeeland, MI) ; Steenwyk; Brian J.; (Holland,
MI) ; McLarty; Michael L.; (Holland, MI) ;
Braun; Randall S.; (Hudsonville, MI) |
Correspondence
Address: |
PRICE, HENEVELD, COOPER, DEWITT, & LITTON,;LLP/GENTEX CORPORATION
695 KENMOOR, S.E., P O BOX 2567
GRAND RAPIDS
MI
49501
US
|
Family ID: |
43354108 |
Appl. No.: |
12/488947 |
Filed: |
June 22, 2009 |
Current U.S.
Class: |
359/267 ;
359/850 |
Current CPC
Class: |
B60R 1/072 20130101;
G02F 1/153 20130101; B60R 1/088 20130101 |
Class at
Publication: |
359/267 ;
359/850 |
International
Class: |
G02F 1/153 20060101
G02F001/153 |
Claims
1. An exterior review mirror element comprising: a front element
having a first front surface and a second rear surface; a rear
element having a third front surface and a fourth rear surface;
electrochromic material located between the front element and the
rear element; a seal abutting the front element and the second
element, the seal substantially surrounding the electrochromic
material; and a spotter optic in contact with the electrochromic
material; at least a portion of the spotter optic having a first
radius of curvature and at least a portion of the first front
surface having a second radius of curvature, the first radius of
curvature being smaller than the second radius of curvature.
2. The exterior rearview mirror element of claim 1, wherein: the
rearview mirror element having a first area not including the
spotter optic and a second area including the spotter optic, the
first area reflecting a first zone and the spotter optic reflecting
a second zone; and the electrochromic material is configured to
reduce the first zone reflectance, but not the second zone
reflectance when the electrochromic material is activated.
3. The exterior rearview mirror element of claim 1, wherein:
wherein the spotter optic is located at the second rear surface of
the front element.
4. The exterior rearview mirror element of claim 1, wherein: the
first front surface is substantially planar.
5. The exterior rearview mirror element of claim 1, wherein: the
rearview mirror element having a first area not including the
spotter optic and a second area including the spotter optic; and
the difference between an average reflectance of the first area and
an average reflectance of the second area is greater than
approximately 5 percent.
6. The exterior rearview mirror element of claim 1, wherein: the
fourth rear surface has a substantially continuous radius of
curvature.
7. The exterior review mirror element of claim 1, wherein: the
spotter optic comprises a convex reflective surface including a
reflective material thereon.
8. The exterior review mirror element of claim 1, further
including: reflective material on the second rear surface covering
the seal to prevent observation of the seal from the first front
surface; wherein the spotter optic comprises a convex reflective
surface located at the second rear surface, the convex reflective
surface further having the reflective material thereon.
9. The exterior review mirror element of claim 8, wherein: the
reflective material covering the seal and the reflective material
of the convex reflective surface is contiguous.
10. An exterior review mirror element comprising: a front element
having a first front surface and a second rear surface; a rear
element having a third front surface and a fourth rear surface;
electrochromic material located between the front element and the
rear element; and a spotter optic located at the second rear
surface of the front element, the spotter optic having a reflective
coating; at least a portion of the spotter optic having a first
radius of curvature and at least a portion of the first front
surface having a second radius of curvature, the first radius of
curvature being smaller than the second radius of curvature;
wherein an electrical potential is applied across a first electrode
coating on the second surface and a second electrode coating on the
third surface changing an absorption of the electrochromic material
in order to reduce a reflection off of the exterior rearview mirror
element; and wherein the reflective coating of the spotter optic
forms a portion of the first electrode coating in contact with the
electrochromic material.
11. The exterior rearview mirror element of claim 10, wherein: the
rearview mirror element having a first area not including the
spotter optic and a second area including the spotter optic, the
first area reflecting a first zone and the spotter optic reflecting
a second zone; and the electrochromic material is configured to
reduce the first zone reflectance, but not the second zone
reflectance when the electrochromic material is activated.
12. The exterior rearview mirror element of claim 10, wherein: the
first front surface is substantially planar.
13. The exterior rearview mirror element of claim 10, wherein: the
rearview mirror element having a first area not including the
spotter optic and a second area including the spotter optic, the
first area reflecting a first zone and the spotter optic reflecting
a second zone; and the first area has a different reflectance than
the second area.
14. The exterior rearview mirror element of claim 10, wherein: the
fourth rear surface has a substantially continuous radius of
curvature.
15. The exterior review mirror element of claim 10, wherein: the
spotter optic comprises a convex reflective surface having the
reflective coating thereon.
16. An exterior review mirror element comprising: a front element
having a first front surface and a second rear surface, the second
rear surface having a first electrode coating thereon; a rear
element having a third front surface and a fourth rear surface, the
third front surface having a second electrode coating thereon;
electrochromic material located between the front element and the
rear element; and a spotter optic located at the second rear
surface of the front element, the spotter optic having a reflective
coating; at least a portion of the spotter optic having a first
radius of curvature and at least a portion of the first front
surface having a second radius of curvature, the first radius of
curvature being smaller than the second radius of curvature;
wherein the first electrode coating and the reflective coating abut
and overlap such that a line perpendicular to the first front
surface of the front element extends through both the first
electrode coating and the reflective coating.
17. The exterior rearview mirror element of claim 16, wherein: the
rearview mirror element having a first area not including the
spotter optic and a second area including the spotter optic, the
first area reflecting a first zone and the spotter optic reflecting
a second zone; and the electrochromic material is configured to
reduce the first zone reflectance, but not the second zone
reflectance when the electrochromic material is activated.
18. The exterior rearview mirror element of claim 16, wherein: the
first electrode coating and the reflective coating overlap at least
0.5 mm substantially around a perimeter of the spotter optic.
19. The exterior rearview mirror element of claim 16, wherein: the
rearview mirror element having a first area not including the
spotter optic and a second area including the spotter optic; and
the difference between the average reflectance of the first area
and the average reflectance of the second area is greater than
approximately 5 percent.
20. The exterior rearview mirror element of claim 16, wherein: the
fourth rear surface has a substantially continuous radius of
curvature.
21. The exterior rearview mirror element of claim 16, wherein: the
spotter optic comprises a convex reflective surface having the
reflective coating thereon.
Description
FIELD OF THE INVENTION
[0001] The present invention concerns vehicle mirrors, and more
particularly relates to rearview mirrors having a spotter
mirror.
BACKGROUND OF THE INVENTION
[0002] Electrochromic elements are used in a variety of
applications including light shutters, variable attenuating optical
filters, and architectural and vehicle windows. The most common
application of electrochromic elements is in rearview mirror
assemblies used in vehicles. Such electrochromic rearview mirrors
are controlled to vary the reflectivity of the mirror in response
to rearward and forward aimed light sensors so as to reduce the
glare of headlamps in the image reflected to the driver's eyes.
SUMMARY OF THE PRESENT INVENTION
[0003] An aspect of the present invention is to provide an exterior
review mirror element comprising a front element having a first
front surface and a second rear surface, a rear element having a
third front surface and a fourth rear surface, and electrochromic
material located between the front element and the rear element. A
seal abuts the front element and the second element, with the seal
substantially surrounding the electrochromic material. A spotter
optic is in contact with the electrochromic material. At least a
portion of the spotter optic has a first radius of curvature and at
least a portion of the first front surface has a second radius of
curvature, with the first radius of curvature being smaller than
the second radius of curvature.
[0004] Another aspect of the present invention is to provide an
exterior review mirror element comprising a front element having a
first front surface and a second rear surface, a rear element
having a third front surface and a fourth rear surface, and
electrochromic material located between the front element and the
rear element. A spotter optic is located at the second rear surface
of the front element, with the spotter optic having a reflective
coating. At least a portion of the spotter optic has a first radius
of curvature and at least a portion of the first front surface has
a second radius of curvature, with the first radius of curvature
being smaller than the second radius of curvature. An electrical
potential is applied across a first electrode coating on the second
surface and a second electrode coating on the third surface
changing an absorption of the electrochromic material in order to
reduce a reflection off of the exterior rearview mirror element.
The reflective coating of the spotter optic forms a portion of the
first electrode coating in contact with the electrochromic
material.
[0005] Yet another aspect of the present invention is to provide an
exterior review mirror element comprising a front element having a
first front surface and a second rear surface, with the second rear
surface having a first electrode coating thereon, a rear element
having a third front surface and a fourth rear surface, with the
third front surface having a second electrode coating thereon, and
electrochromic material located between the front element and the
rear element. A spotter optic is located at the second rear surface
of the front element, with the spotter optic having a reflective
coating. At least a portion of the spotter optic has a first radius
of curvature and at least a portion of the first front surface has
a second radius of curvature, with the first radius of curvature
being smaller than the second radius of curvature. The first
electrode coating and the reflective coating abut and overlap such
that a line perpendicular to the first front surface of the front
element extends through both the first electrode coating and the
reflective coating.
[0006] These and other aspects, objects, and features of the
present invention will be understood and appreciated by those
skilled in the art upon studying the following specification,
claims, and appended drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0007] FIG. 1 is a front view of a first embodiment of an exterior
review mirror element embodying the present invention.
[0008] FIG. 2 is a cross-section view of the first embodiment of
the exterior review mirror element embodying the present invention
taken along the line II-II of FIG. 1.
[0009] FIG. 3A is a schematic top view of the first embodiment of
an exterior review mirror element embodying the present invention
illustrating areas of reflection of the first embodiment of an
exterior review mirror element embodying the present invention.
[0010] FIG. 3B is a schematic top view of a first surface spotter
mirror illustrating areas of reflection.
[0011] FIG. 4 is a front view of a second embodiment of an exterior
review mirror element embodying the present invention.
[0012] FIG. 5 is a cross-section view of the second embodiment of
the exterior review mirror element embodying the present invention
taken along the line V-V of FIG. 4.
[0013] FIG. 6 is a front view of a third embodiment of an exterior
review mirror element embodying the present invention.
[0014] FIG. 7 is a cross-section view of the third embodiment of
the exterior review mirror element embodying the present invention
taken along the line VII-VII of FIG. 6.
[0015] FIG. 8 is a front view of a fourth embodiment of an exterior
review mirror element embodying the present invention.
[0016] FIG. 9 is a cross-section view of the fourth embodiment of
the exterior review mirror element embodying the present invention
taken along the line IX-IX of FIG. 8.
[0017] FIG. 10 is a front view of a fifth embodiment of an exterior
review mirror element embodying the present invention.
[0018] FIG. 11 is a cross-section view of the fifth embodiment of
the exterior review mirror element embodying the present invention
taken along the line XI-XI of FIG. 10.
[0019] FIG. 12 depicts an exploded view of an exterior rearview
mirror assembly having the exterior review mirror element of the
present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] For purposes of description herein, the terms "upper,"
"lower," "right," "left," "rear," "front," "vertical,"
"horizontal," and derivatives thereof shall relate to the invention
as orientated in FIG. 1. However, it is to be understood that the
invention may assume various alternative orientations, except where
expressly specified to the contrary. It is also to be understood
that the specific devices and processes illustrated in the attached
drawings, and described in the following specification are simply
exemplary embodiments of the inventive concepts defined in the
appended claims. Hence, specific dimensions and other physical
characteristics relating to the embodiments disclosed herein are
not to be considered as limiting, unless the claims expressly state
otherwise.
[0021] The reference number 10 (FIGS. 1-3) generally designates an
exterior review mirror element embodying the present invention. In
the illustrated example, the exterior review mirror element 10
comprises a front element 12 having a first front surface 14 and a
second rear surface 16 and a rear element 18 having a third front
surface 20 and a fourth rear surface 22. The exterior review mirror
element 10 further includes electrochromic material 24 located
between the front element 12 and the rear element 18. The exterior
review mirror element 10 also includes a spotter optic 26 in
contact with the electrochromic material 24. The rearview mirror
element 10 has a first area 28 not including the spotter optic 26
and a second area 30 including the spotter optic 26. The first area
28 reflects a first zone 32 and the second area 30 reflects a
second zone 34, with the second zone 34 being different than the
first zone 32. The exterior rearview mirror element 10 provides a
driver of a vehicle with two images, with one image providing an
area of view different than the area of view of the other
image.
[0022] The illustrated exterior review mirror element 10 (FIGS.
1-2) includes the front element 12 and the rear element 18, with a
layer of electrochromic (EC) material 24 therebetween. A top
electrical conductor 40 and a bottom electrical conductor 42 are in
electrical contact with opposing sides of the EC material 24 and
are operably connected to a control circuit on a circuit board as
is well known to those skilled in the art.
[0023] FIGS. 1 and 2 illustrate the exterior rearview mirror
element 10 constructed in accordance with a first embodiment of the
present invention. A chamber 48 is defined by the top electrical
conductor 40 (carried on the second rear surface 16), the bottom
electrical conductor 42 (disposed on the third front surface 20),
and an inner circumferential wall 54 of a sealing member 56. The EC
medium 24 is contained within the chamber 48. As broadly used and
described herein, the reference to an electrode, conductor or layer
as being "carried" on a surface of an element refers to both
electrodes or layers that are disposed directly on the surface of
an element or disposed on another coating, layer or layers that are
disposed directly on the surface of the element.
[0024] In the illustrated example, the front element 12 may be any
material which is transparent and has sufficient strength to be
able to operate in the conditions (e.g., varying temperatures and
pressures) commonly found in the automotive environment. The front
element 12 may comprise any type of borosilicate glass, soda lime
glass, float glass, or any other material, such as, for example, a
polymer or plastic, that is transparent in the visible region of
the electromagnetic spectrum. The front element 12 is preferably a
sheet of glass. The rear element 18 must meet the operational
conditions outlined above, except that it does not need to be
transparent in all applications, and therefore may comprise
polymers, metals, glass, ceramics, and preferably is a sheet of
glass. It is contemplated that the first front surface 14 of the
front element 12 could include an anti-reflective coating thereon
(over the entire surface or just a portion thereof (e.g., over the
spotter optic 26)).
[0025] The bottom electrical conductor 42 on the third front
surface 20 is sealably bonded to the top electrical conductor 40 on
the rear second surface 16 in a spaced-apart and parallel
relationship by the sealing member 56 disposed near an outer
perimeter of both the second rear surface 16 and the third front
surface 20. The sealing member 56 may be any material that is
capable of adhesively bonding the coatings on the second rear
surface 16 to the coatings on the third front surface 20 to seal
the perimeter such that electrochromic material 24 does not leak
from chamber 48. As described below, the top electrical conductor
40 and/or the bottom electrical conductor 42 may be removed over a
portion where the sealing member 56 is disposed. In such a case,
the sealing member 56 should bond well to glass.
[0026] The performance requirements for the sealing member 56 used
in an electrochromic device are similar to those for a perimeter
seal used in a liquid crystal device (LCD), which are well known in
the art. The seal must have good adhesion to glass, metals and
metal oxides; must have low permeabilities for oxygen, moisture
vapor, and other detrimental vapors and gases; and must not
interact with or poison the electrochromic or liquid crystal
material it is meant to contain and protect. The perimeter seal can
be applied by means commonly used in the LCD industry, such as by
silk-screening or dispensing. Because of their lower processing
temperatures, thermoplastic, thermosetting or UV curing organic
sealing resins are preferred. Such organic resin sealing systems
for LCDs are described in U.S. Pat. Nos. 4,297,401, 4,418,102,
4,695,490, 5,596,023, and 5,596,024. Because of their excellent
adhesion to glass, low oxygen permeability and good solvent
resistance, epoxy-based organic sealing resins are preferred. These
epoxy resin seals may be UV curing, such as described in U.S. Pat.
No. 4,297,401, or thermally curing, such as with mixtures of liquid
epoxy resin with liquid polyamide resin or dicyandiamide, or they
can be homopolymerized. The epoxy resin may contain fillers or
thickeners to reduce flow and shrinkage such as fumed silica,
silica, mica, clay, calcium carbonate, alumina, etc., and/or
pigments to add color. Fillers pretreated with hydrophobic or
silane surface treatments are preferred. Cured resin crosslink
density can be controlled by use of mixtures of mono-functional,
di-functional, and multi-functional epoxy resins and curing agents.
Additives such as silanes, titanates, or sulfur or phosphorous
compounds can be used to improve the seal's hydrolytic stability
and adhesion, and spacers such as glass or plastic beads or rods
can be used to control final seal thickness and substrate spacing.
Suitable epoxy resins for use in the sealing member 56 include, but
are not limited to: "EPON RESIN" 813, 825, 826, 828, 830, 834, 862,
1001F, 1002F, 2012, DPS-155, 164, 1031, 1074, 58005, 58006, 58034,
58901, 871, 872, and DPL-862 available from Shell Chemical Co.,
Houston, Tex.; "ARALITE" GY 6010, GY 6020, CY 9579, GT 7071, XU
248, EPN 1139, EPN 1138, PY 307, ECN 1235, ECN 1273, ECN 1280, MT
0163, MY 720, MY 0500, MY 0510, and PT 810 available from Ciba
Geigy, Hawthorne, N.Y.; and "D.E.R." 331, 317, 361, 383, 661, 662,
667, 732, 736, "D.E.N." 354, 354LV, 431, 438, 439 and 444 available
from Dow Chemical Co., Midland, Mich. Suitable epoxy curing agents
include V-15, V-25, and V-40 polyamides from Shell Chemical Co.;
"AJICURE" PN-23, PN-34, and VDH available from Ajinomoto Co.,
Tokyo, Japan; "CUREZOL" AMZ, 2MZ, 2E4MZ, C11Z, C17Z, 2PZ, 21Z, and
2P4MZ available from Shikoku Fine Chemicals, Tokyo, Japan; "ERISYS"
DDA or DDA accelerated with U-405, 24EMI, U-410, and U-415
available from CVC Specialty Chemicals, Maple Shade, N.J.; and
"AMICURE" PACM, 2049, 352, CG, CG-325, and CG-1200 available from
Air Products, Allentown, Pa. Suitable fillers include fumed silica
such as "CAB-O-SIL" L-90, LM-130, LM-5, PTG, M-5, MS-7, MS-55,
TS-720, HS-5, and EH-5 available from Cabot Corporation, Tuscola,
Ill.; "AEROSIL" R972, R974, R805, R812, R812 S, R202, US204, and
US206 available from Degussa, Akron, Ohio. Suitable clay fillers
include BUCA, CATALPO, ASP NC, SATINTONE 5, SATINTONE SP-33,
TRANSLINK 37, TRANSLINK 77, TRANSLINK 445, and TRANSLINK 555
available from Engelhard Corporation, Edison, N.J. Suitable silica
fillers are SILCRON G-130, G-300, G-100-T, and G-100 available from
SCM Chemicals, Baltimore, Md. Suitable silane coupling agents to
improve the seal's hydrolytic stability are Z-6020, Z-6030, Z-6032,
Z-6040, Z-6075, and Z-6076 available from Dow Corning Corporation,
Midland, Mich. Suitable precision glass microbead spacers are
available in an assortment of sizes from Duke Scientific, Palo
Alto, Calif. The seal may be constructed in accordance with the
teachings in U.S. Pat. Nos. 5,790,298 and 6,157,480, the entire
disclosures of which are incorporated herein by reference.
[0027] Another suitable way to maintain precision spacing between
the front element 12 and the rear element 18 is by adding plastic
fibers to the sealing material 56. These fibers, if cut from
monofilament in an aspect ratio of about 2.5 to 3 to 1 (length to
diameter), are particularly effective in keeping the front element
12 and the rear element 18 from sliding during the seal cure
process. The glass spheres act as ball bearings that can enable
movement between the front element 12 and the rear element 18
during seal cure. Plastic fibers made of high temperature polyester
(PEN) or polyetherimide (UItem) when added to the sealing material
56 at around a 1% by weight loading help prevent movement of the
front element 12 and the rear element 18 because they are randomly
orientated and some will not be positioned to roll. These plastic
spacers have another benefit in that they more closely match the
thermal expansion of cured organic sealing material and
consequently will generate less seal stress during thermal
cycling.
[0028] The top electrical conductor 40 is deposited on the second
rear surface 16 to act as an electrode. The top electrical
conductor 40 is transparent and may be any material which bonds
well to the front element 12, is resistant to corrosion to any
materials within the exterior review mirror element 10, is
resistant to corrosion by the atmosphere or road salts, has minimal
diffuse or specular reflectance, high light transmission, near
neutral coloration, and good electrical conductance. The top
electrical conductor 40 may be fluorine-doped tin oxide, doped zinc
oxide, indium zinc oxide (ZN31n206), indium tin oxide (ITO),
ITO/metal/ITO (IMI) as disclosed in "Transparent Conductive
Multilayer-Systems for FPD Applications," by J. Stollenwerk, B.
Ocker, K. H. Kretschmer of LEYBOLD AG, Alzenau, Germany, the
materials described in above-referenced U.S. Pat. No. 5,202,787,
such as TEC 20 or TEC 15, available from Libbey-Owens-Ford Co. of
Toledo, Ohio, other transparent conductive metal oxides, or other
transparent conductors. Generally, the conductance of the top
electrical conductor 40 will depend on its thickness and
composition. IMI generally has superior conductivity compared with
the other materials. IMI, however, is known to undergo more rapid
environmental degradation and suffer from interlayer delamination.
The thicknesses of the various layers in the IMI structure may
vary, but generally the thickness of the first ITO layer ranges
from about 10 .ANG. to about 200 .ANG., the metal ranges from about
10 .ANG. to about 200 .ANG., and the second layer of ITO ranges
from about 10 .ANG. to about 200 .ANG.. If desired, an optional
layer or layers of a color suppression material (not shown) may be
deposited between The top electrical conductor 40 and the second
rear surface 16 to suppress the reflection of any unwanted portions
of the electromagnetic spectrum.
[0029] The bottom electrical conductor 42 may be a combination
reflector/electrode and is preferably disposed on the third front
surface 20. The bottom electrical conductor 42 comprises at least
one layer of a reflective material, which serves as a mirror
reflectance layer and also forms an integral electrode in contact
with and in a chemically and electrochemically stable relationship
with any constituents in the electrochromic medium 24. The bottom
electrical conductor 42 may be mostly reflective or may be
partially transmissive/partially reflective (or "transflective") as
disclosed in commonly-assigned U.S. patent application Ser. No.
10/115,860, filed on Apr. 3, 2002, entitled "ELECTROCHROMIC
REARVIEW MIRROR ASSEMBLY INCORPORATING A DISPLAY/SIGNAL LIGHT," by
William L. Tonar et al., now U.S. Pat. No. 6,700,692, the entire
disclosure of which is incorporated herein by reference. As an
alternative, exterior review mirror element 10 could incorporate a
transparent conductive material on the third surface, which acts as
an electrode, and incorporate a reflector on the fourth surface.
However, combining the "reflector" and "electrode" and placing both
on the third surface is preferred because it makes the device
manufacture less complex and allows the device to operate with
higher performance. The bottom electrical conductor 42 is a
combined reflector/electrode on the third surface which generally
has higher conductance than a conventional transparent electrode as
used on the third surface. One can either change the composition of
the top electrical conductor 40 on the second surface to one that
has lower conductance (being cheaper and easier to produce and
manufacture) while maintaining coloration speeds similar to that
obtainable with a fourth surface reflector device, while at the
same time decreasing substantially the overall cost and time to
produce the electrochromic device. If, however, performance of a
particular design is of utmost importance, a moderate to high
conductance transparent electrode can be used on the second
surface, such as, for example, ITO, IMI, etc. The combination of a
high conductance (i.e., less than 250 preferably less than 15)
reflector/electrode on the third surface and a high conductance
transparent electrode on the second surface will not only produce
an electrochromic device with more even overall coloration, but
will also allow for increased speed of coloration and clearing.
Furthermore, in fourth surface reflector mirror assemblies, there
are two transparent electrodes with relatively low conductance, and
in previously used third surface reflector mirrors, there is a
transparent electrode and a reflector/electrode with relatively low
conductance and, as such, a long buss bar on the front and rear
element to bring current in and out is necessary to ensure adequate
coloring speed. The bottom electrical conductor 42 of the present
invention can be metallic and have a higher conductance and
therefore has a very even voltage or potential distribution across
the conductive surface, even with a small or irregular contact
area, thereby providing greater design flexibility by allowing the
electrical contact for the third surface electrode to be very small
(if desired) while still maintaining adequate coloring speed.
[0030] It can be desirable in the construction of outside rearview
mirrors to incorporate at least one thinner glass element in order
to decrease the overall weight of the mirror so that the mechanisms
used to manipulate the orientation of the mirror are not
overloaded. Decreasing the weight of the device also improves the
dynamic stability of the mirror assembly when exposed to
vibrations. Alternatively, decreasing the weight of the mirror
element may permit more electronic circuitry to be provided in the
mirror housing without increasing the weight of the mirror housing.
In the illustrated embodiment, the first substrate 12 comprises
glass that is at least 2.0 mm in thick, although either thicker or
thinner glass can be used. The thicker glass provides for a greater
grind depths and a greater field of view for a given grind radius.
To reduce the weight of the exterior rearview mirror element 10,
the rear substrate 18 can comprise a piece of glass or other
substrate that is thinner than the first substrate 12. The rear
substrate 18 can be about 1.6 mm thick or less. More preferably,
the rear substrate 18 can be about 1.1 mm or less. Thin glass may
be prone to warpage or breakage, especially when exposed to extreme
environments. This problem is substantially improved by using an
improved electrochromic device incorporating two thin glass
elements having an improved gel material. This improved device is
disclosed in commonly assigned U.S. Pat. No. 5,940,201 entitled
"ELECTROCHROMIC MIRROR WITH TWO THIN GLASS ELEMENTS AND A GELLED
ELECTROCHROMIC MEDIUM," filed on Apr. 2, 1997. The entire
disclosure of this patent is incorporated herein by reference. The
addition of the bottom electrical conductor 42 that is a combined
reflector/electrode onto the third front surface 20 of the exterior
review mirror element 10 further helps remove any residual double
imaging resulting from the two glass elements being out of
parallel. Thus, the chamber 48 preferably contains a free-standing
gel that cooperatively interacts with thin glass elements and to
produce the exterior review mirror element 10 that acts as one
thick unitary member rather than two thin glass elements held
together only by a seal member. In free-standing gels, which
contain a solution and a cross-linked polymer matrix, the solution
is interspersed in a polymer matrix and continues to function as a
solution. Also, at least one solution-phase electrochromic material
is in solution in the solvent and therefore as part of the solution
is interspersed in the polymer matrix (this generally being
referred to as "gelled electrochromic medium"). This allows one to
construct the exterior review mirror element 10 with thinner glass
in order to decrease the overall weight of the exterior review
mirror element 10 while maintaining sufficient structural integrity
so that the exterior review mirror element 10 will survive the
extreme conditions common to the automobile environment. This also
helps maintain uniform spacing between the thin glass elements,
which improves uniformity in the appearance (e.g., coloration) of
the exterior review mirror element 10. This structural integrity
results because the free-standing gel, the front element 12, and
the rear element 18, which individually have insufficient strength
characteristics to work effectively in an electrochromic mirror,
couple in such a manner that they no longer move independently but
act as one thick unitary member. This stability includes, but is
not limited to, resistance to flexing, warping, bowing and
breaking, as well as improved image quality of the reflected image,
e.g., less distortion, double image, color uniformity, and
independent vibration of each glass element. However, while it is
important to couple the front element 12 and the rear element 18,
it is equally important (if not more so) to ensure that the
exterior review mirror element 10 functions properly. The
free-standing gel must bond to the electrode layers (including the
reflector/electrode if the mirror has a third surface reflector) on
the walls of such a device, but not interfere with the electron
transfer between the electrode layers and the electrochromic
material(s) disposed in the chamber 48. Further, the gel must not
shrink, craze, or weep over time such that the gel itself causes
poor image quality. The device described above can ensure that the
free-standing gel bonds well enough to the electrode layers to
couple the front element 12 and the rear element 18 and does not
deteriorate over time while allowing the electrochromic reactions
to take place as though they were in solution.
[0031] To perform adequately, the exterior review mirror element 10
must accurately represent the reflected image, and this cannot be
accomplished when the front element 12 and the rear element 18 tend
to bend or bow while the driver is viewing the reflected image. The
bending or bowing occurs mainly due to pressure points exerted by
the mirror mounting and adjusting mechanisms and by differences in
the coefficients of thermal expansion of the various components
that are used to house the exterior mirror element. These
components include a carrier plate used to attach the mirror
element to the mechanism used to manipulate or adjust the position
of the mirror (bonded to the mirror by an adhesive), a bezel, and a
housing. Many mirrors also typically have a potting material as a
secondary seal. Each of these components, materials, and adhesives
has varying coefficients of thermal expansion that will expand and
shrink to varying degrees during heating and cooling and will exert
stress on the front element 12 and the rear element 18. On very
large mirrors, hydrostatic pressure becomes a concern and may lead
to double imaging problems when the front element 12 and the rear
element 18 bow out at the bottom and bow in at the top of the
exterior review mirror element 10. By coupling the front element 12
and the rear element 18, the thin/free-standing gel/thin element
combination acts as one thick unitary member (while still allowing
proper operation of the exterior review mirror element 10) and
thereby reduces or eliminates the bending, bowing, flexing, double
image, and distortion problems and non-uniform coloring of the
electrochromic medium 24.
[0032] The cooperative interaction between the free-standing gel
and the thin glass elements of the present invention also improves
the safety aspects of exterior review mirror element 10 having thin
elements. In addition to being more flexible, thin elements are
more prone to breakage than thick elements. By coupling the
free-standing gel with the thin elements, the overall strength is
improved (as discussed above) and further restricts shattering and
scattering and eases clean-up in the case of breakage of the
exterior review mirror element 10.
[0033] The improved cross-linked polymer matrix used in the present
invention is disclosed in commonly assigned U.S. Pat. No. 5,928,572
entitled "ELECTROCHROMIC LAYER AND DEVICES COMPRISING SAME" filed
on Mar. 15, 1996. The entire disclosure of this patent is
incorporated herein by reference.
[0034] A resistive heater 670 (see FIG. 12) may be disposed on the
fourth rear surface 22 to heat the exterior review mirror element
10 and thereby clear the exterior review mirror element 10 of ice,
snow, fog, or mist. The resistive heater may optionally be a layer
of ITO, fluorine-doped tin oxide applied to the fourth surface, or
may be other heater layers or structures well known in the art. It
is contemplated that the rear fourth surface 22 of the rear element
18 could be flat or have a continuous radius without a depression
to allow the heater to abut the rear elements 18 without any
spacing and to allow the heater to easily abut the rear fourth
surface 22.
[0035] An electrical circuit such as those taught in the
above-referenced Canadian Patent No. 1,300,945 and U.S. Pat. Nos.
5,204,778, 5,434,407, 5,451,822, 6,402,328, and 6,386,713, is
connected to and allows control of the potential to be applied
across the top electrical conductor 40 and the bottom electrical
conductor 42, such that electrochromic medium 24 will darken and
thereby attenuate various amounts of light traveling therethrough
and thus vary the reflectance of the exterior review mirror element
10 containing electrochromic medium 24. The electrical circuit used
to control the reflectivity of the exterior review mirror element
10 preferably incorporates an ambient light sensor (not shown) and
a glare light sensor (not shown), the glare light sensor being
positioned either behind the exterior review mirror element 10 and
looking through a section of the exterior review mirror element 10
with the reflective material completely or partially removed, or
the glare light sensor can be positioned outside the reflective
surfaces (e.g., in a bezel 58Z) or positioned behind a uniformly
deposited transflective coating. Additionally, an area or areas of
the electrode and reflector may be completely removed or partially
removed to permit a vacuum fluorescent display, such as a compass,
clock, or other indicia, to show through to the driver of the
vehicle or as also described below, this light emitting display
assembly can be shown through a uniformly deposited transflective
coating. The present invention is also applicable to a mirror which
uses only one video chip light sensor to measure both glare and
ambient light and which is further capable of determining the
direction of glare.
[0036] FIGS. 1 and 2 illustrate the first embodiment of the
exterior rearview mirror element 10 of the present invention. In
the first embodiment of the exterior rearview mirror element 10,
the spotter optic 26 comprises a convex reflector 44 on the second
rear surface 16 of the front element 12 (as viewed from the front
of the exterior rearview mirror element 10). The convex reflector
44 includes a substantially spherical surface 46 having a
reflective coating 49 thereon. As illustrated in FIG. 1, the convex
reflector 44 defines the first area 28 of the exterior rearview
mirror element 10 such that the first area 28 is smaller than the
second area 30 of the exterior rearview mirror element 10. In the
illustrated example, the spotter optic 26 has at least a portion
thereof having a smaller radius of curvature than the radius of
curvature of the first front surface 14 of the front element 12.
For example, the spotter optic 26 can be substantially spherical or
aspheric and the first front surface 14 can also be substantially
spherical or aspheric, but with the first front surface 14 having a
portion with a larger radius of curvature than the radius of
curvature of the spotter optic. It is further considered that the
first front surface 14 can be flat (radius of curvature=.infin.)
and the spotter optic 26 can be substantially spherical or
aspheric. Thus, it is contemplated that a first front surface 14
that is flat does have a radius of curvature, with the radius of
curvature being infinity.
[0037] In the illustrated example, the reflective coating 49 can be
conductive to form a portion of the top electrical conductor 40.
Therefore, the electrochromic material 24 can darken behind the
spotter optic 26 and below the spotter optic 26. However, the
darkened electrochromic material 24 will not be viewed by the
driver because of the reflective coating 49 will cover the
electrochromic material 24. The reflective coating 49 or an
optional the top electrical conductor 40 behind the reflective
coating 49 allow the spotter optic 26 to contact the electrochromic
material 24. Moreover, as illustrated in FIG. 2, it is contemplated
that the reflective material 49 at a periphery 60 of the convex
reflector 44 could overlap the top electrical conductor 40 at 101
(see FIG. 2) such that a line perpendicular 36 to the first front
surface 14 of the front element 12 extends through both the top
electrical conductor 40 and the reflective material 49. Therefore,
the reflective material 49 could extend beyond the substantially
spherical surface 46 and onto a portion of the remainder of the
second rear surface 16. While the top electrical conductor 40 is
illustrated as being located between the reflective material 49 and
the second rear surface 16 of the front element 12 in FIG. 2, it is
contemplated that the reflective material 49 could be located
between the top electrical conductor 40 and the second rear surface
16 of the front element 12. It is also contemplated that the convex
reflector 44 could overlap the top electrical conductor 40 (either
above or below) by at least 0.5 mm and preferably by at least about
2 mm. Moreover, it is contemplated that the overlap of the convex
reflector 44 and the top electrical conductor 40 encompasses
substantially the entire periphery of the spotter optic 26.
[0038] In the illustrated invention, the exterior review mirror
element 10 provides the driver of a vehicle with the first zone 32
of reflection and the second zone 34 of reflection (see FIG. 3A).
The first zone 32 of reflection is the typical reflection provided
by an exterior side view mirror and allows the driver of the
vehicle to see objects to the side and behind the vehicle within a
first cone of reflection A. The second zone 34 of reflection allows
the driver of the vehicle to see more objects to the side and
behind the vehicle and/or a specific area (e.g., the ground by a
door or blind spots) within a second cone of reflection B. The
second cone of reflection B and the second zone 34 is different
than the first cone of reflection A and the first zone 32.
[0039] As illustrated in FIG. 3A, a point of reference of the
driver of the vehicle is represented by point 50. A first reflected
line 52 represents an image reflected off of the exterior review
mirror element 10 at a point closest to the driver at point 50. A
second reflected line 55 represents an image reflected off of the
exterior review mirror element 10 at a point furthest from the
driver at point 50. As illustrated in FIG. 3A, the angle of
incidence and the angle of reflection of each of lines 52 and 55
are approximately equal (although the angle of incidence and
reflection of line 52 is different that the angle of incidence and
reflection of line 55). A third reflected line 57 represents an
image reflected off of the spotter optic 26 at a point closest to
the driver at point 50. A fourth reflected line 58 represents an
image reflected off of the spotter optic 26 at a point furthest
from the driver at point 50. As illustrated in FIG. 3A, the angle
of incidence of line 57 is smaller than the angle of reflection of
line 57. Conversely, the angle of incidence of line 58 is larger
than the angle of reflection of line 58. Therefore, the second cone
of reflection B and the second zone 34 is different than the first
cone of reflection A and the first zone 32. The spotter optic 26
therefore allows the driver to view an area around the vehicle in
via the spotter optic 26 (the second area 30 of the exterior review
mirror element 10) different than the remainder of the exterior
review mirror element 10 (the first area 28 of the exterior review
mirror element 10). It is noted that the light traveling through
the front element 12 may experience some refraction, thereby
enlarging the second cone of reflection B and the second zone 34
than they would be without any refraction (see below). It is
further noted that FIG. 3A illustrates the reflection of images off
of the exterior review mirror element 10 as taking place off of the
second rear surface 16 of the front element 12 with the
understanding that the images reflected in the first area 28 will
in practice reflect off of the third front surface 20 or the fourth
rear surface 22 of the rear element 18. However, reflection off of
the third front surface 20 or the fourth rear surface 22 of the
rear element 18 in practice will not substantially alter the first
zone 32 as represented in FIG. 3A.
[0040] FIG. 3B illustrates a reflected image from the point of
reference of the driver of the vehicle is represented by point 50
off of a spotter mirror 4 on a front surface 14' of a first element
12'. FIGS. 3A and 3B illustrate the wider field of vision of the
spotter optic 26 of the present invention compared to the spotter
mirror 4 on the first front surface 14' of the first element 12'.
As discussed above, FIG. 3A illustrates the third reflected line 57
and the fourth reflected line 58 as they reflect off of the spotter
optic 26. FIG. 3B illustrates a first reflected line 57' that has
the same angle from the point 50 to the spot that the reflected
line 57' encounters the front surface 14' of the first element 12'
as the third reflected line 57 from the point 50 in FIG. 3A. FIG.
3B also a second reflected line 58' that has the same angle from
the point 50' to the spot that the reflected line 58' encounters
the front surface 14' of the first element 12' as the fourth
reflected line 58 from the point 50 in FIG. 3A. Comparing FIGS. 3A
and 3B, the third reflected line 57 reflected off of the spotter
optic 26 of the present invention has a smaller angle of reflection
than the reflected line 57' reflected off of the spotter mirror 4.
Furthermore, the fourth reflected line 58 reflected off of the
spotter optic 26 of the present invention has a larger angle of
reflection than the reflected line 58' reflected off of the spotter
mirror 4. Therefore, the second cone of reflection B as illustrated
in FIG. 3A is larger than the cone of reflection B' (the area
between lines 57' and 58' of FIG. 3B) as illustrated in FIG. 3B.
For example, it is contemplated that the spotter optic 26 of the
present invention could include a 62.degree. field of view while
the spotter mirror 4 would only have a 33.6.degree. field of view
when the spotter optic 26 and the spotter mirror 4 have identical
dimensions. The second cone of reflection B as illustrated in FIG.
3A is larger than the cone of reflection B' as illustrated in FIG.
3B because the light traveling through the first element 12 is
refracted as illustrated in FIG. 3A. The first element 12 can
therefore be constructed in such a way as to take advantage of the
index of refraction of a transparent substrate to increase the
effective field of view of a reflective surface without the need to
increase the size of the reflecting surface or the need to decrease
the radius of curvature on the reflective surface.
[0041] The examples as shown in FIGS. 3A and 3B illustrate that the
exterior review mirror element 10 can be constructed in such a way
as to take advantage of the index of refraction of the first
element 12 to increase an effective field of view of the spotter
optic 26 without the need to increase the size of the reflecting
surface of the spotter optic 26 and/or the need to decrease a
radius of curvature of the reflecting surface as compared to the
spotter mirror 4 on the first front surface 14'. In other words, if
the spotter optic 26 and the spotter mirror 4 have the same size of
reflecting surface and the same radius of curvature, the spotter
optic 26 will have a larger effective field of view. Nevertheless,
variations of thickness of the first element 12, radius of
curvature of the spotter optic 26, viewing distances (the distance
between the point 50 and the spotter optic 26), location of the
exterior review mirror element 10, index of refraction of the first
element 12, etc. can be modified during design to optimize
performance of the exterior review mirror element 10.
[0042] In the illustrated example, it is contemplated that the
convex reflector 44 could include features to prevent distortion of
the image reflected off of the convex reflector 44. Distortion of
an image viewed at an edge of the convex reflector 44 can be caused
by a change in radius of the substantially spherical surface 46
(e.g., at the intersection of the first front surface 14 of the
front element 12 (having a substantially planar or a radius of
curvature substantially larger than a radius of curvature of the
substantially spherical surface 46) and the substantially spherical
surface 46) and by a rate in change of the radius of curvature of
the substantially spherical surface 46. It is contemplated that the
first front surface 14 of the front element 12 could include a
masking element (e.g., black dots) positioned over the periphery 60
of the convex reflector 44. It is also contemplated that the
reflective coating 49 could be removed adjacent at edges of the
convex reflector 44 and could also include no reflective material
on the third front surface 20 or the fourth rear surface 22 of the
rear element 18 behind the convex reflector 44 (to prevent any
image from being reflected at the edge of the convex reflector 44).
The masking element would prevent an image to be reflected off of
the convex reflector 44 at the areas where distortion would
occur.
[0043] The illustrated spotter optic 26 can also have
characteristics different than the remainder of the exterior
rearview mirror element 10. For example, the spotter optic 26 could
have a different reflectance than the remainder of the exterior
rearview mirror element 10. It is contemplated that the difference
between the average reflectance in the spotter optic 26 and average
reflectance of the remainder of the exterior review mirror element
10 is greater than approximately 5 percent. This provides a
distinguishing characteristic between the two areas to prevent
confusion to the driver. Moreover, the spotter optic 26 could have
a different color than the remainder of the exterior rearview
mirror element 10.
[0044] In the illustrated example, when the spotter optic 26 at the
second rear surface 16 of the front element 12 has electrochromic
material 24 behind the spotter optic 26, activation of the
electrochromic material 24 behind the spotter optic 26 is
relatively invisible compared to the activation of the
electrochromic material 24 in the first area 28. However, there may
however be effects that emanate from the spotter optic 26 affecting
the first area 28. If there are concentrations of active anodic and
cathodic materials in the electrochromic material 24 that form in
imbalanced ratios in certain regions in the exterior rearview
mirror element 10 during an extended period of darkening of the
electrochromic material 24, the darkening of the electrochromic
material 24 in the imbalanced regions may not erase as quickly as
they would if they remained balanced. Moreover, with the area in
the chamber 48 behind the spotter optic 24 being different in size
than for the rest of the chamber 48, segregation of the
electrochromic material 24 may more easily occur, leading to the
imbalanced regions. The chamber 48 may be constructed so that the
area in the chamber 48 behind the spotter optic 26 is relatively
isolated from the rest of the chamber 48. In one embodiment, the
area in the chamber 48 behind the spotter optic 26 is relatively
isolated from the rest of the chamber 48 by adding additional seal
material in the chamber 48 behind the periphery of the spotter
optic 26 to substantially physically isolate the electrochromic
material 26 behind the spotter optic 26 from the electrochromic
material 26 in the remainder of the chamber 48. The additional seal
material will restrict movement of the electrochromic material 24
and may substantially reduce segregation of the electrochromic
material 24. It is contemplated that the additional seal material
around the periphery of the spotter optic 26 does not have to fully
encompass the area in the chamber 48 behind the spotter optic 26.
It is also contemplated that the electrochromic material 24 in the
area in the chamber 48 behind the spotter optic 26 and the rest of
the chamber 48 are continuous. This allows the area in the chamber
48 behind the spotter optic 26 and the rest of the chamber 48 to
fill with electrochromic material 24 in one fill process and
through one opening in the seal 56. Alternatively, the area in the
chamber 48 behind the spotter optic 26 and the rest of the chamber
48 could be completely isolated, requiring two fill processes. One
skilled in the art will recognize that materials other than the
seal material could be added around the periphery of the spotter
optic 26 to substantially physically isolate the electrochromic
material 26 behind the spotter optic 26 from the electrochromic
material 26 in the remainder of the chamber 48.
[0045] It is contemplated that the first embodiment of the exterior
rearview mirror element 10 with the spotter optic 26 of the present
invention could be made in any manner. For example, the front
element 14 could be formed in a fashion as described above and the
substantially spherical surface 46 could be ground out of the
second rear surface 16 of the front element 12. The substantially
spherical surface 46 could be ground out of the second rear surface
16 of the front element 12 using grinding and polishing methods
known in the art.
[0046] The reference numeral 10a (FIGS. 4-5) generally designates
another embodiment of the present invention, having a second
embodiment for the exterior rearview mirror element. Since exterior
rearview mirror element 10a is similar to the previously described
exterior rearview mirror element 10, similar parts appearing in
FIGS. 1-2 and FIGS. 4-5, respectively, are represented by the same,
corresponding reference number, except for the suffix "a" in the
numerals of the latter. The second embodiment of the exterior
rearview mirror element 10a is substantially identical to the first
embodiment of the exterior rearview mirror element 10, except that
the spotter optic 26a comprises a convex reflector 44a on the
fourth rear surface 22a of the rear element 18a (as viewed from the
front of the exterior rearview mirror element 10a). The convex
reflector 44a includes a substantially spherical surface 46a having
a reflective coating 49a thereon. As illustrated in FIG. 4, the
convex reflector 44a defines the first area 28a of the exterior
rearview mirror element 10a such that the first area 28a is much
smaller than the second area 30a of the exterior rearview mirror
element 10a. It is noted that both the top electrical conductor 40a
and the bottom electrical conductor 42a are transparent in the
second embodiment of the exterior rearview mirror element 10a.
[0047] In the illustrated example, the substantially spherical
surface 46a can be formed in the fourth rear surface 22a in the
same manner as the substantially spherical surface 46 is formed in
the second rear surface 16 of the first embodiment of the exterior
rearview mirror element 10 as described above. Moreover, it is
contemplated that the first front surface 14, the second rear
surface 16 and/or the third front surface 20 could include a
masking element (e.g., black dots) positioned over a periphery 60a
of the convex reflector 44a and/or the reflective coating 49a could
be removed adjacent at edges of the convex reflector 44a to prevent
an image to be reflected off of the convex reflector 44a at the
areas where distortion would occur.
[0048] The reference numeral 10b (FIGS. 6-7) generally designates
another embodiment of the present invention, having a third
embodiment for the exterior rearview mirror element. Since exterior
rearview mirror element 10b is similar to the previously described
exterior rearview mirror element 10, similar parts appearing in
FIGS. 1-2 and FIGS. 6-7, respectively, are represented by the same,
corresponding reference number, except for the suffix "b" in the
numerals of the latter. The third embodiment of the exterior
rearview mirror element 10b is substantially identical to the first
embodiment of the exterior rearview mirror element 10, except that
the reflective coating 49b is contiguous with a spectral filter
material 100 covering a periphery 102 of second rear surface 16b of
the front element 12b. The spectral filter material 100 is used to
cover the seal 56b. Furthermore, the spectral filter material 100
can be reflective to provide the third embodiment of the exterior
rearview mirror element 10b with a large reflective surface. The
spectral filter material 100 can also extend slightly beyond the
extent of the substantially spherical surface 46b as illustrated in
FIG. 6. The spectral filter material 100 can be made of chrome
and/or aluminum and/or other reflective materials. Using a spectral
filter material 100 with an exterior review mirror element, its
composition, its properties and its application along with
properties of the materials adjacent the spectral filter material
100 are described in U.S. Pat. No. 7,372,611 entitled VEHICULAR
REARVIEW MIRROR ELEMENTS AND ASSEMBLIES INCORPORATING THESE
ELEMENTS, the entire contents of which is hereby incorporated
herein by reference.
[0049] The reference numeral 10c (FIGS. 8-9) generally designates
another embodiment of the present invention, having a fourth
embodiment for the exterior rearview mirror element. Since exterior
rearview mirror element 10c is similar to the previously described
exterior rearview mirror element 10, similar parts appearing in
FIGS. 1-2 and FIGS. 8-9, respectively, are represented by the same,
corresponding reference number, except for the suffix "c" in the
numerals of the latter. The fourth embodiment of the exterior
rearview mirror element 10c is substantially similar to the first
embodiment of the exterior rearview mirror element 10, except that
the spotter optic 26c comprises a convex reflector 44c including a
protruding spherical surface 46c protruding from the first front
surface 14c of the front element 12c (instead of the spotter optic
26c being at the second rear surface). It is contemplated that the
front element 12c having the protruding spherical surface 46c could
be formed in any manner. For example, the first front surface 14c
of the front element 12c could be etched to form the protruding
spherical surface 46c or the protruding spherical surface 46c could
comprises a convex reflector 44c adhered or otherwise attached to
the first front surface 14c. It is also contemplated that the
protruding spherical surface could be included on the third front
surface 20 of the rear element 18. In such a situation, the third
front surface, at least at the convex reflector, includes a bottom
electrical conductor that is reflective. Additionally, any masking
material can be located on the first front surface, the second rear
surface and/or the third front surface.
[0050] The reference numeral 10d (FIGS. 10-11) generally designates
another embodiment of the present invention, having a fifth
embodiment for the exterior rearview mirror element. Since exterior
rearview mirror element 10d is similar to the previously described
exterior rearview mirror element 10, similar parts appearing in
FIGS. 1-2 and FIGS. 10-11, respectively, are represented by the
same, corresponding reference number, except for the suffix "d" in
the numerals of the latter. The fifth embodiment of the exterior
rearview mirror element 10d is substantially identical to the first
embodiment of the exterior rearview mirror element 10, except that
the fifth embodiment of the exterior rearview mirror element 10d
only includes a front element 12d (with no rear element 18 and no
electrochromic material 24). Furthermore, the first front surface
14d of the front element 12d includes reflective material 200
except in front of at least a portion of the spotter optic 26d.
Moreover, it is contemplated that the reflective material 200 could
be used as a masking element positioned over various portions of
the convex reflector 26d to prevent an image from being reflected
off of the convex reflector 26d at areas where distortion would
occur or where a rearward field of view is not desired.
[0051] Turning now to FIG. 12, there is shown an exploded view of
an exterior rearview mirror assembly 705 having the exterior
rearview mirror element 10, 10a or 10b. The exterior rearview
mirror assembly 705 has a housing 710 connected to an attachment
member 715 via a telescoping extension 720. In at least one
embodiment, the telescoping extension 720 comprises a single arm
having a linear actuator for extending and retracting the
telescoping extension from within the associated vehicle. The
telescoping extension 720 may comprise a rack and pinion type
linear actuator, an electrical solenoid type linear actuator, a
pneumatic piston or a hydraulic actuator. The housing 710 may be
configured such that the housing axially pivots about the
telescoping extension. Additionally, the telescoping extension may
be configured such that the housing may be folded inward toward the
associated vehicle and outward away from the associated vehicle.
The attachment member 715 is configured to be received by a vehicle
mount 725. The vehicle mount may be fixed to a door panel, an
A-pillar, a front fender, a window assembly, or any other position
where a driver can view the scene generally rearward of the
associated vehicle. It should be understood that the telescoping
extension may comprise two or more arms and that the housing may be
configured to pivot and fold irrespective of the number of arms
employed. It should also be understood that the housing may be
connected to a non-telescoping extension at a location shown as
reference number 720a such that the housing pivots about the
connection 720a such that the mirror may be positioned closer or
farther from the vehicle as desired. This feature may be
accompanied by a power positioning mechanism such that actuation
may be performed inside the vehicle. It should be understood that
the mirror housing, extension, and attachment member may be
configured such that the telescoping, pivoting, and folding
requires a manual operation.
[0052] A wiring harness 730 with a connector 735 is provided to
interface the exterior mirror with associated apparatus located
inside the associated vehicle. The wiring harness may be configured
to provide extension, folding and pivoting of the housing and may
also be configured to provide reflective element control,
electrical power, turn signal actuation, mirror heater control,
mirror element positioning, light sensor interface, exterior mirror
circuit board interface, transceiver interface, information display
interface, antenna interface, light source power and control,
emergency flasher interface, and all other electrical features as
described herein. It should be understood that operator interfaces
are provided within the vehicle for each of these features where
appropriate.
[0053] A mirror element positioner 740 is provided for aligning the
associated reflective element within the housing from the interior
of the associated vehicle. It should be understood that a
corresponding operator interface is provided within the vehicle for
positioning of the reflective element.
[0054] The positioner 740 is mechanically connected to a carrier
745 for providing a secure structure for supporting and moving of
the associated reflective element. Examples of suitable carriers
are described in U.S. Pat. Nos. 6,195,194 and 6,239,899, the
disclosures of which are incorporated herein in their entireties by
reference.
[0055] In at least one embodiment, a double-sided adhesive foam 750
is employed to attach the reflective element to the carrier. In
certain instances, apertures 751 may be provided in the
double-sided adhesive foam for accommodating positioning of various
components.
[0056] In at least one embodiment, an electrical circuit board 755
is provided in the rearview mirror assembly. The electrical circuit
board may comprise a light source such as a turn signal light, a
keyhole illuminator, or an outside door area illuminator, as taught
in U.S. Pat. No. 6,441,943, the entire disclosure of which is
incorporated in its entirety herein by reference, an information
display, an antenna, a transceiver, a reflective element control,
an outside mirror communication system, a remote keyless entry
system, proximity sensors, and interfaces for other apparatus
described herein. U.S. Pat. Nos. 6,244,716, 6,523,976, 6,521,916,
6,441,943, 6,335,548, 6,132,072, 5,803,579, 6,229,435, 6,504,142,
6,402,328, 6,379,013, and 6,359,274 disclose various electrical
components and electrical circuit boards that may be employed in
one or more embodiments, the disclosures of each of these U.S.
patents are incorporated herein in their entireties by
reference.
[0057] In at least one embodiment, a rearview mirror assembly is
provided with a heater 760 for improving the operation of the
device and for melting frozen precipitation that may be present.
Examples of various heaters are disclosed in U.S. Pat. Nos.
5,151,824, 6,244,716, 6,426,485, 6,441,943 and 6,356,376, the
disclosures of each of these patents are incorporated in their
entireties herein by reference.
[0058] In at least one embodiment, the rearview mirror assembly is
provided with a bezel 780 for protecting the associated seal from
damaging light rays and to provide an aesthetically pleasing
appearance. Examples of various bezels are disclosed in U.S. Pat.
Nos. 5,448,397, 6,102,546, 6,195,194, 5,923,457, 6,238,898,
6,170,956 and 6,471,362, the disclosures of which are incorporated
herein in their entireties by reference.
[0059] It is contemplated that the spotter optic 26 could abut an
edge of the front element 12 and/or rear element 18 (instead of
being located within a central area of the elements as illustrated)
such that the spotter optic is not circular. Moreover, it is
contemplated that the spotter optic 26 could be non-spherical
and/or have a non-circular periphery. Additionally, it is
contemplated that the spotter optic 26 could comprise a lens
instead of a mirror such that images reflected off of the third
front surface 20 or the fourth rear surface 22 pass through a lens
that bends the light such that the lens forms the first area 28
that reflects the first zone 32, with the second zone 34 being
larger than the first zone 32. Moreover, it is contemplated that a
third element could be employed with the spotter optic 26 on the
third element such that the third element becomes the rear element
and the rear element as discussed above is fully transparent or
transparent in front of the spotter optic 26 on the third element.
Additionally, adjustment of the relative color of the second area
30, the spectral filter material 100 and the first area 28 can be
obtained by various methods. One embodiment is an application of a
chrome layer in the second area 30 between successive application
of layers of the top electrical conductor 40 (e.g., indium tin
oxide ("ITO")). Another embodiment involves adding the top
electrical conductor 40 to the second rear surface 14 of front
element 12 before the spotter optic 26 is formed and then
subsequently forming the spotter optic 26 in the second rear
surface 14 and then adding the top electrical conductor 40 in the
second area 30 and on the spectral filter material 100. Such
techniques are related to those discussed in U.S. Pat. No.
7,372,611, the entire contents of which are hereby incorporated
herein by reference. Some predetermined degree of color difference
between the first area 28 and the second area 30 may assist in easy
and quick location of the spotter optic 26 by the driver, yet color
differences that are too great might be regarded as aesthetically
undesirable, depending on the hues involved and the magnitude of
those differences.
[0060] It is to be understood that variations and modifications can
be made on the aforementioned structure without departing from the
concepts of the present invention. Furthermore, it is to be
understood that such concepts are intended to be covered by the
following claims unless these claims by their language expressly
state otherwise.
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