U.S. patent application number 15/984499 was filed with the patent office on 2018-09-20 for light-emitting device and backlight module using the same.
The applicant listed for this patent is Genesis Photonics Inc.. Invention is credited to Cheng-Wei Hung, Yu-Feng Lin.
Application Number | 20180269182 15/984499 |
Document ID | / |
Family ID | 56923785 |
Filed Date | 2018-09-20 |
United States Patent
Application |
20180269182 |
Kind Code |
A1 |
Hung; Cheng-Wei ; et
al. |
September 20, 2018 |
LIGHT-EMITTING DEVICE AND BACKLIGHT MODULE USING THE SAME
Abstract
A light-emitting device is provided. The light-emitting device
includes a substrate having a long edge and a short edge, at least
one electrode pad assembly, and at least one light-emitting
element. The at least one electrode pad assembly is disposed on the
substrate and includes a first electrode pad and a second electrode
pad. The at least one light-emitting element has a plurality of
electrodes electrically connected to the first electrode pad and
the second electrode pad of the at least one electrode pad
assembly. The first electrode pad and the second electrode pad are
arranged along a direction parallel to the short side.
Inventors: |
Hung; Cheng-Wei; (Tainan
City, TW) ; Lin; Yu-Feng; (Tainan City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Genesis Photonics Inc. |
Tainan City |
|
TW |
|
|
Family ID: |
56923785 |
Appl. No.: |
15/984499 |
Filed: |
May 21, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15073705 |
Mar 18, 2016 |
9978718 |
|
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15984499 |
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62134577 |
Mar 18, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 25/0753 20130101;
H01L 27/0248 20130101; H01L 33/50 20130101; H01L 33/60 20130101;
H01L 25/0657 20130101; H01L 2933/0058 20130101; H01L 25/0756
20130101; H01L 33/52 20130101; H01L 2224/49107 20130101; H01L 23/60
20130101; H01L 33/647 20130101; H01L 23/562 20130101; H01L 29/866
20130101; H01L 33/48 20130101; H01L 25/0655 20130101; H01L 33/08
20130101; H01L 2933/0033 20130101; H01L 2933/0041 20130101; H01L
2224/16225 20130101; H01L 33/508 20130101; H01L 2224/48091
20130101; H01L 33/56 20130101; H01L 33/10 20130101; H01L 33/502
20130101; H01L 33/486 20130101; H01L 33/642 20130101; H01L
2933/0025 20130101; H01L 27/15 20130101; H01L 2924/18161 20130101;
H01L 2224/48091 20130101; H01L 2924/00014 20130101 |
International
Class: |
H01L 25/065 20060101
H01L025/065; H01L 23/60 20060101 H01L023/60; H01L 33/48 20100101
H01L033/48; H01L 33/64 20100101 H01L033/64; H01L 25/075 20060101
H01L025/075; H01L 27/02 20060101 H01L027/02; H01L 27/15 20060101
H01L027/15; H01L 29/866 20060101 H01L029/866; H01L 33/08 20100101
H01L033/08; H01L 33/10 20100101 H01L033/10; H01L 33/60 20100101
H01L033/60; H01L 23/00 20060101 H01L023/00; H01L 33/52 20100101
H01L033/52; H01L 33/50 20100101 H01L033/50 |
Claims
1. A backlight module, comprising: an optics layer having a
light-incoming surface and a light-outgoing surface; and a
light-emitting device facing the light-incoming surface and
comprising: a substrate having a long side and a short side and a
plurality of electrode pad assemblies disposed on the substrate,
wherein each of the electrode pad assemblies comprises a first
electrode pad and a second electrode pad arranged along a direction
parallel to the short side; and a plurality of light-emitting
elements flipped on the substrate, each light-emitting element
comprising: a light emitting diode having a plurality of electrodes
connected to the first electrode pad and the second electrode pad
of one of the electrode pad assemblies; a white reflective layer
attached to a side surface of the light emitting diode and exposed
the electrodes and a top surface of the light emitting diode,
wherein the white reflective layer has a flat lateral surface, and
a bottom surface of the white reflective layer is higher than
bottom surfaces of the electrodes; and a phosphor layer at least
disposed on the top surface of the light emitting diode.
2. The backlight module according to claim 1, wherein each of the
first electrode pad and the second electrode pad of each of the
electrode pad assemblies has a long side and a short side, the long
side of the first electrode pad and the long side of the second
electrode pad are parallel to the long side of the substrate, and
the short side of the first electrode pad and the short side of the
second electrode pad are parallel to the short side of the
substrate.
3. The backlight module according to claim 1, wherein the substrate
comprises: an metal base layer; an insulation layer disposed on the
metal base layer; a plurality of metal layers disposed on the
insulation layer; and a solder resist layer interposed between the
metal layers; wherein the metal layers form the first electrode pad
and the second electrode pad.
4. The backlight module according to claim 1, wherein the bottom
surface of the white reflective layer is not lower than a bottom
surface of the light emitting diode.
5. The backlight module according to claim 1, wherein the
light-emitting device further comprises: a plurality of dome-shaped
sealing structures covering the light-emitting elements.
6. The backlight module according to claim 1, wherein the phosphor
layer is disposed on the white reflective layer and has a flat
lateral surface flush with the flat lateral surface of the white
reflective layer.
7. The backlight module according to claim 6, wherein the phosphor
layer comprises a high-density conversion layer and a low-density
conversion layer, and the high-density conversion layer is
interposed between the at least one light-emitting element and the
low-density conversion layer.
8. The backlight module according to claim 1, wherein the
light-emitting device further comprises: a filling structure
infused between the substrate and the light-emitting elements.
9. The backlight module according to claim 1, wherein each of the
light-emitting elements further comprises a light transmissive
layer disposed on the phosphor layer.
10. A display, comprising a backlight module according to claim 1,
and a display panel disposed on the backlight module to receive a
light emitted from the light-outgoing surface of backlight module.
Description
[0001] This is a Continuation of U.S. application Ser. No.
15/073,705, filed Mar. 18, 2016 which claims the benefit of U.S.
provisional application Ser. No. 62/134,577, filed Mar. 18, 2015,
now in a state of allowability. The content of which is
incorporated herein by reference.
TECHNICAL FIELD
[0002] The disclosure relates in general to a light-emitting device
and a backlight module using the same, and more particularly to a
light-emitting device having different electrode directions and a
backlight module using the same.
BACKGROUND
[0003] Generally speaking, the light-emitting element can be
disposed on a substrate to form a light-emitting device using
flip-chip technology. Typically, the substrate can be realized by a
rectangular substrate having a long side and a short side. However,
when there is a large size difference between the long side and the
short side, the substrate are easily warped, causing damage to the
light-emitting elements disposed on the substrate.
[0004] Therefore, it has become a prominent task for the industries
to provide a light-emitting device capable of resolving the above
problems.
SUMMARY
[0005] The present disclosure is directed to a light-emitting
device and a backlight module using the same. By changing the
arrangement of electrode pads on the substrate, the strength of the
light-emitting elements bonded to the substrate can be effectively
enhanced to avoid the light-emitting elements being peeled off from
the substrate.
[0006] According to one embodiment of the present disclosure, a
backlight module is provided. The backlight module includes an
optics layer and a light-emitting device. The optics layer has a
light-incoming surface and a light-outgoing surface. The
light-emitting device faces the light-incoming surface and includes
a substrate and a plurality of light-emitting elements. The
substrate has a long side and a short side and a plurality of
electrode pad assemblies disposed on the substrate, wherein each of
the electrode pad assemblies comprises a first electrode pad and a
second electrode pad arranged along a direction parallel to the
short side. The light-emitting elements is flipped on the
substrate, each light-emitting element includes a light emitting
diode, a white reflective layer and a phosphor layer. The light
emitting diode has a plurality of electrodes connected to the first
electrode pad and the second electrode pad of one of the electrode
pad assemblies. The white reflective layer is attached to a side
surface of the light emitting diode and exposed the electrodes and
a top surface of the light emitting diode, wherein the white
reflective layer has a flat lateral surface, and a bottom surface
of the white reflective layer is higher than bottom surfaces of the
electrodes. The phosphor layer is at least disposed on the top
surface of the light emitting diode.
[0007] According to another embodiment of the present disclosure, a
display is provided. The display includes the backlight module as
disclosed above and a display panel. The display panel is disposed
on the backlight module to receive a light emitted from the
light-outgoing surface of backlight module.
[0008] According to another embodiment of the present disclosure, a
light-emitting device is provided. The light-emitting device
includes a substrate, at least one electrode pad assembly and at
least one light-emitting element. The substrate has a long side and
a short side. The electrode pad assembly is disposed on the
substrate, and includes a first electrode pad and a second
electrode pad. The light-emitting element has a plurality of
electrodes electrically connected to the first electrode pad and
the second electrode pad of the at least one electrode pad
assembly. The first electrode pad and the second electrode pad are
arranged along a direction parallel to the short side.
[0009] According to another embodiment of the present disclosure, a
backlight module is provided. The backlight module includes a light
guide plate, a light-emitting device and at least one reflective
element. The light guide plate has a light-incoming surface and a
light-outgoing surface adjacent to the light-incoming surface. The
light-emitting device faces the light-incoming surface, and
includes a substrate, at least one electrode pad assembly and at
least one light-emitting element. The electrode pad assembly is
disposed on the substrate, and includes a first electrode pad and a
second electrode pad. The light-emitting element has a plurality of
electrodes electrically connected to the first electrode pad and
the second electrode pad of at least one electrode pad assembly.
The reflective element reflects lights emitted from the
light-emitting device. The first electrode pad and the second
electrode pad are arranged along a direction perpendicular to the
light-outgoing surface.
[0010] The above and other aspects of the present disclosure will
become better understood with regard to the following detailed
description of the preferred but non-limiting embodiment (s). The
following description is made with reference to the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a top view of a light-emitting device according to
an embodiment of the present disclosure.
[0012] FIGS. 2A and 2B are cross-sectional views of a
light-emitting device along a line segment A-A' of FIG. 1 according
to an embodiment of the present disclosure.
[0013] FIGS. 3A and 3B are cross-sectional views of a
light-emitting device along a line segment A-A' of FIG. 1 according
to another embodiment of the present disclosure.
[0014] FIG. 4 is a schematic diagram of a backlight module
according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0015] A number of embodiments of the present disclosure are
disclosed below with reference to accompanying drawings. However,
the structure and content disclosed in the embodiments are for
exemplary and explanatory purposes only, and the scope of
protection of the present disclosure is not limited to the
embodiments. Designations common to the accompanying drawings and
embodiments are used to indicate identical or similar elements. It
should be noted that the present disclosure does not illustrate all
possible embodiments, and anyone skilled in the technology field of
the present disclosure will be able to make suitable modifications
or changes based on the specification disclosed below to meet
actual needs without breaching the spirit of the present
disclosure. The present disclosure is applicable to other
implementations not disclosed in the specification. In addition,
the drawings are simplified such that the content of the
embodiments can be clearly described, and the shapes, sizes and
scales of elements are schematically shown in the drawings for
explanatory and exemplary purposes only, not for limiting the scope
of protection of the present disclosure.
[0016] FIG. 1 is a top view of a light-emitting device 100
according to an embodiment of the present disclosure. FIGS. 2A and
2B are cross-sectional views of a light-emitting device 100 along a
line segment A-A' of FIG. 1 according to an embodiment of the
present disclosure. FIG. 2A is a schematic diagram of a substrate
10 and a light-emitting element 40 having not been combined
together. FIG. 2B is a schematic diagram of a substrate 10 and a
light-emitting element 40 having been combined together. It should
be noted that some elements (such as the light-emitting element 40)
are omitted in FIG. 1 so that the relationship between the elements
disposed on the substrate 10 can be more clearly illustrated.
[0017] As indicated in FIGS. 1, 2A, 2B, the light-emitting device
100 of the present disclosure embodiment includes a substrate 10,
at least one electrode pad assembly 30 and at least one
light-emitting element 40. In the present embodiment, the electrode
pad assembly 30 is disposed on the substrate 10. For example, the
electrode pad assembly 30 may be disposed at a predetermined
position 20 corresponding to the light-emitting element 40. The
electrode pad assembly 30 may include a first electrode pad 301 and
a second electrode pad 302.
[0018] It should be noted that although the light-emitting device
100 illustrated in FIG. 1 includes 5 electrode pad assemblies 30,
the present disclosure is not limited thereto. The quantity of
electrode pad assemblies 30 of the light-emitting device 100 may be
adjusted to fit design needs.
[0019] The light-emitting element 40, which can be realized by such
as a light-emitting diode (LED), has a plurality of electrodes 401
and 402 electrically connected to the first electrode pad 301 and
the second electrode pad 302 of the electrode pad assembly 30. As
indicated in FIG. 2A, the part between the electrode 401 of the
light-emitting element 40 and the first electrode pad 301 of the
electrode pad assembly 30 and the part between the electrode 402 of
the light-emitting element 40 and the second electrode pad 302 of
electrode pad assembly 30 may further include a solder paste
33.
[0020] In the present embodiment, the substrate 10 has a long side
10-1 and a short side 10-2, and the first electrode pad 301 and the
second electrode pad 302 of the electrode pad assembly 30 are
arranged along a direction parallel to the short side 10-2. That
is, the substrate 10 has a plurality of electrodes (at least two)
along the direction parallel to the short side 10-2.
[0021] For example, the substrate 10 may have a rectangular shape,
the long side 10-1 is parallel to the X-axis of FIG. 1, and the
short side 10-2 is parallel to the Y-axis of FIG. 1. That is, the
long side 10-1 is perpendicular to the short side 10-2, and the
first electrode pad 301 and the second electrode pad 302 of the
electrode pad assembly 30 are arranged along the direction parallel
to the Y-axis of FIG. 1.
[0022] In an embodiment, each of the first electrode pad 301 and
the second electrode pad 302 has a rectangular shape. That is, each
of the first electrode pad 301 and the second electrode pad 302 has
a long side and a short side. As indicated in FIG. 1, the long side
of the first electrode pad 301 and the long side of the second
electrode pad 302 are parallel to the long side 10-1 of the
substrate 10, and the short side of the first electrode pad 301 and
the short side of the second electrode pad 302 is parallel to the
short side 10-2 of the substrate 10. However, the present
disclosure is not limited thereto. The first electrode pad 301 and
the second electrode pad 302 may have other shapes. For example,
each of the first electrode pad 301 and the second electrode pad
302 has a squared shape.
[0023] In an embodiment, the substrate 10 is a printed circuit
board (PCB), such as an aluminum substrate including an aluminum
base layer 11, an insulation layer 13, a plurality of
copper-containing metal layers 31 and a solder resist layer 15. The
insulation layer 13 is disposed on the aluminum base layer 11. The
copper-containing metal layers 31 are disposed on the insulation
layer 13, and correspond to the positions of the first electrode
pad 301 and the second electrode pad 302 of the electrode pad
assembly 30. The solder resist layer 15 is interposed between the
copper-containing metal layers 31.
[0024] However, the present disclosure is not limited thereto, and
the substrate 10 of the light-emitting device 100 may be formed of
other materials. For example, the substrate 10 may be formed of
CEM-3 or FR-4.
[0025] As indicated in FIG. 2B, the solder paste 33 may connect the
electrodes 401 and 402 of the light-emitting element 40 with the
first electrode pad 301 and the second electrode pad 302 of the
electrode pad assembly 30 to combine the substrate 10 with the
light-emitting element 40. In the present embodiment, the
light-emitting device 100 may further include a sealing structure
61, which covers the light-emitting element 40 after the substrate
10 and the light-emitting element 40 are combined together. In some
embodiments, the sealing structure 61 may include a number of
phosphor particles, such that the lights emitted from the
light-emitting element 40 may have different colors.
[0026] In the present embodiment, the light-emitting device 100 is
not limited to the structure illustrated in FIGS. 2A and 2B. FIGS.
3A and 3B are cross-sectional views of a light-emitting device 100
along a line segment A-A' of FIG. 1 according to another embodiment
of the present disclosure. FIG. 3A is a schematic diagram of a
substrate 10 and a light-emitting element 40 having not been
combined together. FIG. 3B is a schematic diagram of a substrate 10
and a light-emitting element 40 having been combined together.
[0027] In the present embodiment, the light-emitting device 100
includes a wavelength conversion layer 50, which may be disposed on
the light-emitting element 40. The wavelength conversion layer 50
includes a number of phosphor particles. In some embodiments as
indicated in FIGS. 3A and 3B, the wavelength conversion layer 50
may include a high-density conversion layer 501 and a low-density
conversion layer 502, wherein the area having a higher density of
phosphor particles is defined as the high-density conversion layer
501, and the area having a lower density of phosphor particles is
defined as the low-density conversion layer 502. In an embodiment,
the ratio of density of phosphor particles of the high-density
conversion layer 501 to the density of phosphor particles of the
low-density conversion layer 502 may range between 1 and 10.sup.15.
In other embodiments of the present disclosure, the low-density
conversion layer 502 of the wavelength conversion layer 50 may be a
transparent layer without any phosphor particles. In one embodiment
of the present disclosure, the high-density conversion layer 501
and the low-density conversion layer 502 may be formed concurrently
or separately.
[0028] In the present embodiment, the high-density conversion layer
501 is interposed between the light-emitting element 40 and the
low-density conversion layer 502. That is, the lights emitted from
the light-emitting element 40 firstly pass through the high-density
conversion layer 501 and then exit via the low-density conversion
layer 502. The design of the high-density conversion layer 501
allows the light color of the lights emitted from several
light-emitting devices 100 to have a centralized distribution on
the chromaticity coordinates, such that the product yield of the
light-emitting devices 100 may be increased. The low-density
conversion layer 502 enables the lights emitted from the
light-emitting element 40 to have a larger probability to be
mixed.
[0029] In the present embodiment, the thickness T2 of the
low-density conversion layer 502 is larger than the thickness T1 of
the high-density conversion layer 501. For example, the ratio of
the thickness T2 of the low-density conversion layer 502 to the
thickness T1 of the high-density conversion layer 501 may range
between 1 and 100.
[0030] In the present embodiment, the wavelength conversion layer
50 may cover the entire top surface 41 of the light-emitting
element 40. That is, the top view area of the wavelength conversion
layer 50 is larger than the top view area of the light-emitting
element 40. For example, the ratio of the top view area of the
wavelength conversion layer 50 to the top view area of the
light-emitting element 40 may range between 1 and 1.35, but the
present disclosure is not limited thereto. In some embodiments, the
ratio of the top view area of the wavelength conversion layer 50 to
the top view area of the light-emitting element 40 may be larger
than 1.35.
[0031] In an embodiment, the wavelength conversion layer 50 may be
formed of sulfide, yttrium aluminum garnet (YAG), LuAG, silicate,
nitride, oxynitride, fluoride, TAG, KSF, and KTF.
[0032] Besides, the light-emitting device 100 of the present
embodiment may further include a reflective structure 70, which may
cover a lateral side of the light-emitting element 40 and a part of
the wavelength conversion layer 50 to effectively protect and avoid
the light-emitting element 40 and the wavelength conversion layer
50 from being exposed and damaged. The reflective structure 70,
realized by such as white glue, may reflect the lights emitted from
the lateral side of the light-emitting element 40 to the wavelength
conversion layer 50 to increase the luminous efficiency of the
light-emitting device 100.
[0033] In an embodiment, the reflectivity of the reflective
structure 70 may be higher than 90%. The reflective structure 70
may be formed of poly phthalic amide (PPA), polyamide (PA),
polyethylene terephthalate (PTT), polyethylene terephthalate (PET),
polyethylene terephthalate 1,4-cyclohexane dimethylene
terephthalate (PCT), epoxy compound (EMC), silicone compound (SMC)
or other resin/ceramics having a high reflectivity.
[0034] Similarly, as indicated in FIG. 3B, the solder paste 33 may
connect the electrodes 401 and 402 of the light-emitting element 40
with the first electrode pad 301 and the second electrode pad 302
of the electrode pad assembly 30 to combine the substrate 10 with
the light-emitting element 40. In the present embodiment, the
light-emitting device 100 may further include a filling structure
62 infused between the substrate 10 and the light-emitting element
40 after the substrate 10 and the light-emitting element 40 are
combined together.
[0035] As disclosed in above embodiments, the first electrode pad
301 and the second electrode pad 302 of the electrode pad assembly
30 are arranged along the direction parallel to the short side
10-2, such that the strength of the light-emitting element 40 on
the substrate 10 may be increased. Although the large size
difference between the long side 10-1 and the short side 10-2 may
cause warpage to the substrate 10, the light-emitting element 40
would not be damaged easily.
[0036] Furthermore, the light-emitting device 100 of the present
disclosure may be used in a backlight module to form an edge type
backlight module. FIG. 4 is a schematic diagram of a backlight
module 1 according to an embodiment of the present disclosure. As
indicated in FIG. 4, the backlight module 1 may include a light
guide plate 80, a light-emitting device and at least one reflective
element 90. The backlight module 1 may be disposed on one side of
the display panel 2.
[0037] The light guide plate 80 has a light-incoming surface 801
and a light-outgoing surface 802 adjacent to the light-incoming
surface 801. The light-emitting device faces the light-incoming
surface 801 of the light guide plate 80. The reflective element 90
reflects the lights emitted from the light-emitting device.
[0038] The light-emitting device may be realized by such as the
light-emitting device 100 illustrated in FIGS. 1, 2B and 3B. That
is, the light-emitting device may include a substrate 10, at least
one electrode pad assembly 30 and at least one light-emitting
element 40. The electrode pad assembly 30 is disposed on the
substrate 10, and includes a first electrode pad 301 and a second
electrode pad 302. The light-emitting element 40 has a plurality of
electrodes connected to the first electrode pad 301 and the second
electrode pad 302 of the electrode pad assembly 30.
[0039] In an embodiment, the reflective element 90 is disposed at
the bottom of the light guide plate 80. When the lights enter the
light guide plate 80 from the light-emitting element 40 of the
light-emitting device via the light-incoming surface 801 of the
light guide plate 80, the reflective element 90 would then reflect
the lights to the light-outgoing surface 802 of the light guide
plate 80. The reflective element 90 may be realized by such as a
reflective plate, but the present disclosure is not limited
thereto, and any reflective element capable of reflecting the
lights emitted from the light-emitting element 40 of the
light-emitting device may be used in the backlight module 1 of the
present disclosure.
[0040] In the present embodiment, the first electrode pad 301 and
the second electrode pad 302 of the electrode pad assembly 30 are
arranged along a direction perpendicular to the light-outgoing
surface 802. That is, the backlight module 1 has a number of
electrode pads (at least two) along the direction perpendicular to
the light-outgoing surface 802. For example, the first electrode
pad 301 and the second electrode pad 302 may be arranged along a
direction parallel to the Y-axis of FIG. 4.
[0041] Similarly, the substrate 10 may be realized by such as a
rectangular substrate having a long side and a short side. FIG. 4
only shows the short side of the substrate 10 (parallel to the
Y-axis). The first electrode pad 301 and the second electrode pad
302 of the electrode pad assembly 30 are arranged along a direction
parallel to the short side of the substrate 10.
[0042] In an embodiment, each of the first electrode pad 301 and
the second electrode pad 302 may be realized by a rectangular
electrode. That is, each of the first electrode pad 301 and the
second electrode pad 302 has a long side and a short side. The long
side of the first electrode pad 301 and the long side of the second
electrode pad 302 may be parallel to the long side of the substrate
10, and the short side of the first electrode pad 301 and the short
side of the second electrode pad 302 may be parallel to the short
side of the substrate 10.
[0043] Due to the design of the first electrode pad 301 and the
second electrode pad 302 of the electrode pad assembly 30 being
arranged along the direction perpendicular to the light-outgoing
surface 802, the strength of the light-emitting element 40 on the
substrate 10 may be increased, such that the light-emitting element
40 would not be easily peeled off the substrate 10.
[0044] It will be apparent to those skilled in the art that various
modifications and variations can be made to the disclosed
embodiments. It is intended that the specification and examples be
considered as exemplary only, with a true scope of the present
disclosure being indicated by the following claims and their
equivalents.
* * * * *