U.S. patent application number 16/371145 was filed with the patent office on 2020-10-01 for light-emitting device display.
The applicant listed for this patent is MIKRO MESA TECHNOLOGY CO., LTD.. Invention is credited to Li-Yi CHEN.
Application Number | 20200312221 16/371145 |
Document ID | / |
Family ID | 1000005087291 |
Filed Date | 2020-10-01 |
United States Patent
Application |
20200312221 |
Kind Code |
A1 |
CHEN; Li-Yi |
October 1, 2020 |
LIGHT-EMITTING DEVICE DISPLAY
Abstract
A light-emitting device display comprising a first
light-emitting device and a second light emitting device is
provided. The first light-emitting device and the second
light-emitting device have a first forward voltage and a second
forward voltage respectively, and the second forward voltage is
higher than the first forward voltage. A first scan voltage and a
second scan voltage is respectively provided to the first
light-emitting device and the second light-emitting device. The
first scan voltage is switched between a first scan-on voltage and
a first scan-off voltage. The second scan voltage is switched
between a second scan-on voltage and a second scan-off voltage. An
absolute value of a difference between the second scan-on voltage
and the second scan-off voltage is greater than an absolute value
of a difference between the first scan-on voltage and the first
scan-off voltage.
Inventors: |
CHEN; Li-Yi; (Tainan City,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MIKRO MESA TECHNOLOGY CO., LTD. |
APIA |
|
WS |
|
|
Family ID: |
1000005087291 |
Appl. No.: |
16/371145 |
Filed: |
April 1, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G09G 3/32 20130101; G09G
3/2003 20130101; G09G 2300/0426 20130101; G09G 2300/0452 20130101;
H01L 27/156 20130101 |
International
Class: |
G09G 3/32 20060101
G09G003/32; G09G 3/20 20060101 G09G003/20; H01L 27/15 20060101
H01L027/15 |
Claims
1. A light-emitting device display, comprising: a pixel comprising:
a first light-emitting device having a first forward voltage; a
second light-emitting device having a second forward voltage,
wherein the second forward voltage is higher than the first forward
voltage; a first type scan line electrically connected to and in
direct contact with a first end of the first light-emitting device,
wherein the first type scan line is configured to receive a first
scan voltage and provide the first scan voltage to the first
light-emitting device, and the first scan voltage is switched
between a first scan-on voltage and a first scan-off voltage; a
second type scan line electrically connected to and in direct
contact with a first end of the second light-emitting device,
wherein the second type scan line is configured to receive a second
scan voltage and provide the second scan voltage to the second
light-emitting device, the second scan voltage is switched between
a second scan-on voltage and a second scan-off voltage, and an
absolute value of a difference between the second scan-on voltage
and the second scan-off voltage is greater than an absolute value
of a difference between the first scan-on voltage and the first
scan-off voltage; and two data lines electrically connected to and
in contact with a second end of the first light-emitting device and
a second end of the second light-emitting device, respectively,
wherein one of the data lines is configured to receive a first data
voltage and provide the first data voltage to the first
light-emitting device, another of the data lines is configured to
receive a second data voltage and provide the second data voltage
to the second light-emitting device, the first data voltage is
higher than or equal to the first scan voltage and the second scan
voltage, and the second data voltage is higher than or equal to the
first scan voltage and the second scan voltage.
2. The light-emitting device display of claim 1, wherein the first
data voltage and the second data voltage are higher than or equal
to a zero voltage.
3. The light-emitting device display of claim 1, wherein an upper
limit of a difference between the first data voltage and the first
scan-off voltage is less than or equal to the first forward
voltage.
4. The light-emitting device display of claim 1, wherein an upper
limit of a difference between the second data voltage and the
second scan-off voltage is less than or equal to the second forward
voltage.
5. The light-emitting device display of claim 1, wherein an upper
limit of a difference between the first data voltage and the first
scan-off voltage and an upper limit of a difference between the
second data voltage and the second scan-off voltage are less than
or equal to the first forward voltage.
6. The light-emitting device display of claim 1, wherein the pixel
further comprises a third data line and a third light-emitting
device having a third forward voltage higher than the first forward
voltage, the second type scan line is electrically connected to and
in contact with a first end of the third light-emitting device, the
third data line is configured to receive a third data voltage and
provide the third data voltage to the third light-emitting device,
the third data line is electrically connected to a second end of
the third light-emitting device, and the third data voltage is
higher than or equal to the first scan voltage and the second scan
voltage.
7. The light-emitting device display of claim 6, wherein an upper
limit of a difference between the third data voltage and the second
scan-off voltage is less than or equal to the first forward
voltage.
8. The light-emitting device display of claim 6, wherein an upper
limit of a difference between the third data voltage and the second
scan-off voltage is less than or equal to the third forward
voltage.
9. The light-emitting device display of claim 6, wherein an upper
limit of a difference between the third data voltage and the second
scan-off voltage is less than or equal to the smaller one of the
second forward voltage and the third forward voltage.
10. The light-emitting device display of claim 6, wherein the third
light-emitting device is a green light-emitting diode.
11. The light-emitting device display of claim 6, wherein the third
data voltage is higher than or equal to a zero voltage.
12. The light-emitting device display of claim 1, wherein the first
light-emitting device is a red light-emitting diode.
13. The light-emitting device display of claim 1, wherein the
second light-emitting device is a blue light-emitting diode.
Description
BACKGROUND
Field of Invention
[0001] The present disclosure relates to a light-emitting device
display with more than one type of scan lines.
Description of Related Art
[0002] The statements in this section merely provide background
information related to the present disclosure and do not
necessarily constitute prior art.
[0003] In recent years, light-emitting diodes (LEDs) have become
popular in general and commercial lighting applications. In some
applications such as displays which are used under a variety of
environmental conditions, a wider modulation range of an LED
brightness output becomes important. Furthermore, a resolution
requirement for the displays is also gradually increasing.
SUMMARY
[0004] According to some embodiments of the present disclosure, a
light-emitting device display is provided. The light-emitting
device display includes a pixel, a first type scan line, a second
type scan line, and two data lines. The pixel includes a first
light-emitting device and a second light-emitting device. The first
light-emitting device has a first forward voltage. The second
light-emitting device has a second forward voltage. The second
forward voltage is higher than the first forward voltage. The first
type scan line is electrically connected to and in contact with a
first end of the first light-emitting device. The first type scan
line is configured to receive a first scan voltage and provide the
first scan voltage to the first light-emitting device. The first
scan voltage is switched between a first scan-on voltage and a
first scan-off voltage. The second type scan line is electrically
connected to and in contact with a first end of the second
light-emitting device. The second type scan line is configured to
receive a second scan voltage and provide the second scan voltage
to the second light-emitting device. The second scan voltage is
switched between a second scan-on voltage and a second scan-off
voltage. An absolute value of a difference between the second
scan-on voltage and the second scan-off voltage is greater than an
absolute value of a difference between the first scan-on voltage
and the first scan-off voltage. Two data lines are electrically
connected to and in contact with a second end of the first
light-emitting device and a second end of the second light-emitting
device, respectively. One of the data lines is configured to
receive a first data voltage and provide the first data voltage to
the first light-emitting device. Another of the data lines is
configured to receive a second data voltage and provide the second
data voltage to the second light-emitting device. The first data
voltage is higher than or equal to the first scan voltage and the
second scan voltage, and the second data voltage is higher than or
equal to the first scan voltage and the second scan voltage.
[0005] It is to be understood that both the foregoing general
description and the following detailed description are by examples,
and are intended to provide further explanation of the disclosure
as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The disclosure can be more fully understood by reading the
following detailed description of the embodiment, with reference
made to the accompanying drawings as follows:
[0007] FIG. 1 is a schematic diagram illustrating a light-emitting
device display in a circuit way according to some embodiments of
the present disclosure;
[0008] FIG. 2A is a schematic diagram illustrating a first scan-on
voltage and a first scan-off voltage provided to a first
light-emitting device according to some embodiments of the present
disclosure;
[0009] FIG. 2B is a schematic diagram illustrating a second scan-on
voltage and a second scan-off voltage provided to a second
light-emitting device according to some embodiments of the present
disclosure;
[0010] FIG. 3A is a schematic cross-sectional view of a portion of
the light-emitting device display according to some embodiments of
the present disclosure;
[0011] FIG. 3B is a schematic cross-sectional view of a first
light-emitting device according to some embodiments of the present
disclosure; and
[0012] FIG. 4 is a schematic diagram illustrating a second scan-on
voltage and a second scan-off voltage provided to a third
light-emitting device according to some embodiments of the present
disclosure.
DETAILED DESCRIPTION
[0013] Reference will now be made in detail to the present
embodiments of the disclosure, examples of which are illustrated in
the accompanying drawings. Wherever possible, the same reference
numbers are used in the drawings and the description to refer to
the same or like parts.
[0014] In various embodiments, description is made with reference
to figures. However, certain embodiments may be practiced without
one or more of these specific details, or in combination with other
known methods and configurations. In the following description,
numerous specific details are set forth, such as specific
configurations, dimensions, and processes, etc., in order to
provide a thorough understanding of the present disclosure. In
other instances, well-known semiconductor processes and
manufacturing techniques have not been described in particular
detail in order to not unnecessarily obscure the present
disclosure. Reference throughout this specification to "one
embodiment," "an embodiment", "some embodiments" or the like means
that a particular feature, structure, configuration, or
characteristic described in connection with the embodiment is
included in at least one embodiment of the disclosure. Thus, the
appearances of the phrase "in one embodiment," "in an embodiment",
"in some embodiments" or the like in various places throughout this
specification are not necessarily referring to the same embodiment
of the disclosure. Furthermore, the particular features,
structures, configurations, or characteristics may be combined in
any suitable manner in one or more embodiments.
[0015] The terms "over," "to," "between" and "on" as used herein
may refer to a relative position of one layer with respect to other
layers. One layer "over" or "on" another layer or bonded "to"
another layer may be directly in contact with the other layer or
may have one or more intervening layers. One layer "between" layers
may be directly in contact with the layers or may have one or more
intervening layers.
[0016] Reference is made to FIGS. 1, 2A, and 2B. FIG. 1 is a
schematic diagram illustrating a light-emitting device display 1000
in a circuit way. FIG. 2A is a schematic diagram illustrating a
first scan-on voltage ON1 and a first scan-off voltage OFF1
provided to a first light-emitting device 110. FIG. 2B is a
schematic diagram illustrating a second scan-on voltage ON2 and a
second scan-off voltage OFF2 provided to a second light-emitting
device 120. The first and second scan-off voltages OFF1, OFF2 can
have the same value, but should not be limited thereto. In some
embodiments, the light-emitting device display 1000 includes a
pixel 100, a first type scan line SC1, a second type scan line SC2,
and two data lines DA. The pixel 100 includes at least a first
light-emitting device 110 and a second light-emitting device 120.
The first light-emitting device 110 has a first forward voltage.
The second light-emitting device 120 has a second forward voltage.
The first and second forward voltages means voltages which are able
to respectively light up the first and the second light-emitting
devices 110, 120. The second forward voltage is higher than the
first forward voltage. The first light-emitting device 110 can be a
red light-emitting diode, and the second light-emitting device 120
can be a blue light-emitting diode, but should not be limited
thereto. The first type scan line SC1 is configured to receive a
first scan voltage SV1 and provide the first scan voltage SV1 to
the first light-emitting device 110. As shown in FIG. 2A, the first
scan voltage SV1 is switched between a first scan-on voltage ON1
and a first scan-off voltage OFF1. The first scan-on voltage ON1 is
corresponding to a light-emitting mode of the first light-emitting
device 110 (i.e., a voltage difference across the first
light-emitting device 110 is greater than the first forward voltage
of the first light-emitting device 110), and the first scan-off
voltage OFF1 is corresponding to a switched-off mode of the first
light-emitting device 110 (i.e., a voltage difference across the
first light-emitting device 110 is smaller than the forward voltage
of the first light-emitting device 110). The second type scan line
SC2 is configured to receive a second scan voltage SV2 and provide
the second scan voltage SV2 to the second light-emitting device
120. The second scan voltage SV2 is switched between a second
scan-on voltage ON2 and a second scan-off voltage OFF2. An absolute
value of a difference between the second scan-on voltage ON2 and
the second scan-off voltage OFF2 is greater than an absolute value
of a difference between the first scan-on voltage ON1 and the first
scan-off voltage OFF1 because it is assumed that the second forward
voltage is higher than the first forward voltage. It is noted that
numbers in the brackets of ON1, ON2, OFF1, and OFF2 (i.e., -1.8,
-2.6, and 0) are only exemplifications and should not be limited
thereto.
[0017] Two data lines DA are electrically connected to the first
light-emitting device 110 and the second light-emitting device 120
respectively. One of the data lines DA is configured to receive a
first data voltage DV1 and provide the first data voltage DV1 to
the first light-emitting device 110. Another of the data lines DA
is configured to receive a second data voltage DV2 and provide the
second data voltage DV2 to the second light-emitting device. The
first data voltage DV1 is higher than or equal to the first scan
voltage SV1 and the second scan voltage SV2, and the second data
voltage DV2 is higher than or equal to the first scan voltage SV1
and the second scan voltage SV2. In some embodiments, the first
data voltage DV1 and the second data voltage DV2 are higher than or
equal to a zero voltage.
[0018] In some embodiments, an upper limit of a difference between
the first data voltage DV1 and the first scan-off voltage OFF1 is
less than or equal to the first forward voltage. This condition is
to ensure that the first light-emitting device 110 is switched off
(i.e., not being lighted up) when the first scan voltage SV1 is
switched to the first scan-off voltage OFF1. In some embodiments,
an upper limit of a difference between the second data voltage DV2
and the second scan-off voltage OFF2 is less than or equal to the
second forward voltage. This condition is to ensure that the second
light-emitting device 120 is switched off (i.e., not being lighted
up) when the second scan voltage SV2 is switched to the second
scan-off voltage OFF2. In some embodiments, both of the upper
limits of the difference between the first data voltage DV1 and the
first scan-off voltage OFF1 and the difference between the second
data voltage DV2 and the second scan-off voltage OFF2 are less than
or equal to the first forward voltage. With this condition, the
first data voltage DV1 and the second data voltage DV2 can have the
same voltage range, thus simplifying a circuit design and/or an
arrangement of data voltage sources.
[0019] The above embodiments enhance a modulation range of lighting
of some light-emitting devices in the pixel 100 of the
light-emitting device display 1000. For easier understanding, red,
blue, and green light-emitting diodes will be used to explain the
enhanced modulation range as follows. Due to significant
differences in forward voltages between the red light-emitting
diode (e.g., about 1.8 volts (V)) and the blue and the green
light-emitting diodes (e.g., about 2.6 V), a modulation range for
the blue and the green light-emitting diodes are restricted to a
narrower range compared to a modulation range of the red
light-emitting diode in conventional passive-matrix displays.
Specifically, in conventional passive-matrix displays in which the
scan lines receive an ON signal (e.g., about -1.8 V) and an OFF
signal (e.g., about 0V) and a data voltage is allowed to be
modulated between 1.8 V and 0 V, the modulation range of the red
light-emitting diode for lighting is thus about 1.8 V, and the
modulation range of the blue and green light-emitting diodes for
lighting is thus about 1 V. The 0.8 V difference is due to
different forward voltages (e.g., 1.8 V for the red light-emitting
diode and 2.6 V for the blue and the green light-emitting diodes)
as shown above. However, in the embodiments of the present
disclosure, at least two different type of scan lines (e.g., the
first type scan line SC1 and the second type scan line SC2) are
respectively connected to the red light-emitting diode and the blue
(or green) light-emitting diode, such that the modulation range of
the blue (or green) light-emitting diode can be the same as the
modulation range of the red light-emitting diode, which means the
modulation range of the blue (or green) light-emitting diode is
enhanced compared to conventional passive-matrix displays. Due to
the enhancement of the modulation range, the blue (or green)
light-emitting diode is allowed to be brighter, and a contrast of
the light-emitting device display 1000 is allowed to be enhanced.
Furthermore a total scan time for each frame of the light-emitting
device display 1000 is allowed to be decreased because a brighter
allowable light intensity emitted from the light-emitting diode can
shorten a lighting time period during each scan time. As such, more
scan lines can be included in the light-emitting device display
1000 and operated within a given frame time, thus enabling a
further enhancement of the resolution of the light-emitting device
display 1000. As an example, a voltage difference between the first
scan-off voltage OFF1 (e.g., about 0 V) and the first scan-on
voltage ON1 (e.g., about -1.8 V) is about 1.8 V, and a voltage
difference between the second scan-off voltage OFF2 (e.g., about 0
V) and the second scan-on voltage ON2 (e.g., about -2.6 V) is about
2.6 V. The first data voltage DV1 and the second data voltage DV2
is set in a range from about 0 V to about 1.8 V. As such, the same
range of the first data voltage DV1 and the second data voltage DV2
can still result in the same modulation range for the first
light-emitting device 110 and the second light-emitting device 120.
In this exemplification, the modulation range for the first
light-emitting device 110 is from about 1.8 V to about 3.6 V, which
is equivalent to 1.8 V, and the modulation range for the second
light-emitting device 120 is from about 2.6 V to about 4.4 V, which
is also equivalent to about 1.8 V. Said 0.8 V difference of the
forward voltages between the red light-emitting diode and the blue
(or green) light-emitting diode is compensated by a presence of
said two types of scan lines in some embodiments of the present
disclosure.
[0020] In another scenario when modulation ranges of the data
voltages for the red light-emitting diode and the blue (or green)
light-emitting diode are allowed to be different, the embodiments
of the present disclosure can also enhance the modulation range of
lighting of the blue (or green) light-emitting diode compared to
the conventional passive-matrix displays. Specifically, a data
voltage applied to the red light-emitting diode is allowed to be
modulated between about 1.8 V and about 0 V, and a data voltage
applied to the blue (or green) light-emitting diode is allowed to
be modulated between about 2.6 V and about 0V. Settings for scan
voltages are the same as those exemplifications described in
previous paragraph. In the conventional passive-matrix displays,
the modulation range of the red light-emitting diode for lighting
is thus about 1.8 V, and the modulation range of the blue (or
green) light-emitting diode for lighting is thus about 1.8 V.
However, in the embodiments of the present disclosure, since there
are at least two different types of scan lines as mentioned above
which are respectively connected to the red light-emitting diode
and the blue (or green) light-emitting diode, the modulation range
of the blue (or green) light-emitting diode for lighting is thus
about 2.6 V, which is substantially enhanced compared to the
conventional passive-matrix displays.
[0021] Reference is made to FIGS. 3A and 3B. FIG. 3A is a schematic
cross-sectional view of a portion of the light-emitting device
display 1000 according to some embodiments of the present
disclosure. FIG. 3B is a schematic cross-sectional view of a first
light-emitting device 110 according to some embodiments of the
present disclosure. In some embodiments, a substrate 140 is
provided. The first type scan line SC1 is on the substrate 140. The
second type scan line SC2 is on the substrate 140. The first type
scan line SC1 is electrically connected to and in contact with a
first end 1102 of the first light-emitting device 110. The second
type scan line SC2 is electrically connected to and in contact with
a first end 1202 of the second light-emitting device 120. Two data
lines DA are electrically connected to and in contact with a second
end 1104 of the first light-emitting device 110 and a second end
1204 of the second light-emitting device 120, respectively. The
first end 1102 and the second end 1104 are on opposite sides of the
first light-emitting device 110. The first end 1202 and the second
end 1204 are on opposite sides of the second light-emitting device
120. A filling material 150 is filled in the light-emitting device
display 1000 and is surrounding the first light-emitting device 110
and the second light-emitting device 120. The filling material 150
is made of dielectric materials or photoresists. In some
embodiments, an isolation structure 160 is between the first
light-emitting device 110 and the second light-emitting device 120
to reduce a cross-talk between different light-emitting devices.
The isolation structure 160 can be a light reflective structure, a
light absorbing structure, or a combination thereof. In some
embodiments, the light reflective structure is on the substrate
140, and the light absorbing structure is on the light reflective
structure. In some embodiments, a passivation layer 170 is on the
data lines DA, the filling material 150, the isolation structure
160, the first light-emitting device 110, and the second
light-emitting device 120. The passivation layer 170 can be used to
enhance the amount of light transmitting out from the
light-emitting device display. In some embodiments, a refractive
index of the passivation layer 170 ranges from about 1.5 to about
2.5. In some embodiments, a cover plate 180 is on the passivation
layer 170. In some embodiments, the first light-emitting device 110
includes a first type semiconductor layer 111 and a second type
semiconductor layer 112 joined with the first type semiconductor
layer 111 through an active layer 113. The first type semiconductor
layer 111 can be a p-type semiconductor layer, and the second type
semiconductor layer 112 can be an n-type semiconductor layer, but
should not be limited thereto. In some embodiments, the first
light-emitting device 110 further includes a reflective layer 114
in contact with the first type semiconductor layer 111, and an
electrode 115 in contact with a side of the reflective layer 114
opposite to the first type semiconductor layer 111. The reflective
layer 114 can be configured to reflect light emitted from the
active layer 113, but should not be limited thereto. The electrode
115 is electrically connected to one of the data lines DA via the
first end 1102. The second type semiconductor layer 112 is
electrically connected to the first type scan line SC1 through the
second end 1104. A structural feature of the second light-emitting
device 120 is similar to that of the first light-emitting device
110 and will not be repeated herein.
[0022] Reference is made back to FIG. 1 and is further made to FIG.
4. FIG. 4 is a schematic diagram illustrating a second scan-on
voltage ON2 and a second scan-off voltage OFF2 provided to a third
light-emitting device 130 according to some embodiments of the
present disclosure. The second scan-off voltage OFF2 can be the
same as the first scan-off voltages OFF1 but should not be limited
thereto. In some embodiments, the pixel 100 further includes
another data line DA and the third light-emitting device 130. The
third light-emitting device 130 has a third forward voltage. The
third forward voltage is higher than the first forward voltage. The
third light-emitting device 130 can be a green light-emitting
diode, but should not be limited thereto. The second type scan line
SC2 is electrically connected to and in contact with a first end of
the third light-emitting device 130. Said another data line DA is
configured to receive a third data voltage DV3 and provide the
third data voltage DV3 to the third light-emitting device 130. Said
another data line DA is electrically connected to a second end of
the third light-emitting device 130. In some embodiments, the third
data voltage DV3 is higher than or equal to the first scan voltage
SV1 and the second scan voltage SV2. The above configuration is
made due to similar forward voltages of the blue and green
light-emitting diodes, such that the blue and green light-emitting
diodes can use the same second scan line SC2. The second and third
light-emitting devices 120, 130 may respectively represent the blue
and green light-emitting diodes, but should not be limited
thereto.
[0023] Similar to the embodiments illustrating the second
light-emitting device 120, in some embodiments, an upper limit of a
difference between the third data voltage DV3 and the second
scan-off voltage OFF2 is less than or equal to the third forward
voltage. In some embodiments, the upper limit of a difference
between the third data voltage DV3 and the second scan-off voltage
OFF2 is less than or equal to the smaller one of the second forward
voltage and the third forward voltage when the second data voltage
DV2 and the third data voltage DV3 have the same voltage range.
This condition is to ensure that the third light-emitting device
130 is switched off (i.e., not being lighted up) when the second
scan voltage SV2 is switched to the second scan-off voltage OFF2.
In some embodiments, the upper limit of the difference between the
first data voltage DV1 and the first scan-off voltage OFF1, the
upper limit of the difference between the second data voltage DV2
and the second scan-off voltage OFF2, and the upper limit of the
difference between the third data voltage DV3 and the second
scan-off voltage OFF2 are less than or equal to the first forward
voltage. With this condition, the first data voltage DV1, the
second data voltage DV2, and the third data voltage DV3 can have
the same voltage range, thus simplifying a circuit design and/or an
arrangement of data voltage sources. In some embodiments, the third
data voltage DV3 is higher than or equal to the zero voltage.
[0024] In summary, a light-emitting device display having two
different types of scan lines which have different on-to-off
voltage differences are provided to enhance a modulation range of
lighting. Light emitting devices having different forward voltages
can have greater modulation range. Furthermore, due to the
enhancement of the modulation range, a contrast and a resolution of
the light-emitting device display is allowed to be further
enhanced.
[0025] Although the present disclosure has been described in
considerable detail with reference to certain embodiments thereof,
other embodiments are possible. Therefore, the spirit and scope of
the appended claims should not be limited to the description of the
embodiments contained herein.
[0026] It will be apparent to those skilled in the art that various
modifications and variations can be made to the structure of the
present disclosure without departing from the scope or spirit of
the disclosure. In view of the foregoing, it is intended that the
present disclosure cover modifications and variations of this
disclosure provided they fall within the scope of the following
claims.
* * * * *