U.S. patent application number 16/172854 was filed with the patent office on 2020-04-30 for method for improving touch performance of capacitive touch screen with non-rectangular shape.
The applicant listed for this patent is HIMAX TECHNOLOGIES LIMITED. Invention is credited to Jen-Chieh LIN, Yan-Hua SHU, Cheng-Hung TSAI, Wai-Pan WU.
Application Number | 20200133410 16/172854 |
Document ID | / |
Family ID | 70327122 |
Filed Date | 2020-04-30 |
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United States Patent
Application |
20200133410 |
Kind Code |
A1 |
TSAI; Cheng-Hung ; et
al. |
April 30, 2020 |
METHOD FOR IMPROVING TOUCH PERFORMANCE OF CAPACITIVE TOUCH SCREEN
WITH NON-RECTANGULAR SHAPE
Abstract
A method for improving touch performance of a capacitive touch
screen with a non-rectangular shape is provided. The capacitive
touch screen includes plural complete cells and at least one
incomplete cell for sensing. The method includes: determining
whether an active area of the incomplete cell is different from an
active area of each of the complete cells; and performing a mutual
capacitance compensation on the incomplete cell to compensate a
mutual capacitance of the incomplete cell when the active area of
the incomplete cell is different from the active area of each of
the complete cells.
Inventors: |
TSAI; Cheng-Hung; (Tainan
City, TW) ; SHU; Yan-Hua; (Tainan City, TW) ;
LIN; Jen-Chieh; (Tainan City, TW) ; WU; Wai-Pan;
(Tainan City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HIMAX TECHNOLOGIES LIMITED |
Tainan City |
|
TW |
|
|
Family ID: |
70327122 |
Appl. No.: |
16/172854 |
Filed: |
October 28, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 3/0412 20130101;
G06F 3/0448 20190501; G06F 3/04886 20130101; G06F 2203/04103
20130101; G06F 3/044 20130101 |
International
Class: |
G06F 3/044 20060101
G06F003/044; G06F 3/041 20060101 G06F003/041; G06F 3/0488 20060101
G06F003/0488 |
Claims
1. A method for improving touch performance of a capacitive touch
screen with a non-rectangular shape, wherein the capacitive touch
screen comprises a plurality of complete cells and at least one
incomplete cell for sensing, the method comprising: determining
whether an active area of the incomplete cell is different from an
active area of each of the complete cells; and performing a mutual
capacitance compensation on the incomplete cell to compensate a
mutual capacitance of the incomplete cell when the active area of
the incomplete cell is different from the active area of each of
the complete cells; wherein the capacitive touch screen comprises a
plurality of receiver (RX) electrodes and a plurality of transmit
(TX) electrodes; wherein an intersection of one of the RX
electrodes and one of the TX electrodes corresponds to one of the
complete cells or the incomplete cell; wherein performing the
mutual capacitance compensation comprises: determining whether the
incomplete cell has a residual area; and modifying a layout pattern
of the incomplete cell of the capacitive touch screen to compensate
the mutual capacitance of the incomplete cell when the incomplete
cell has the residual area.
2. (canceled)
3. The method of claim 1, wherein the mutual capacitance
compensation is performed only when the active area of the
incomplete cell is smaller than or equal to a half of the active
area of each of the complete cells.
4. The method of claim 1, wherein modifying the layout pattern of
the incomplete cell comprises: increasing an overlap area of the
corresponding RX electrode and the corresponding TX electrode of
the incomplete cell.
5. The method of claim 1, wherein modifying the layout pattern of
the incomplete cell comprises: adjusting a layout pattern of a
co-plane differential coupling trace of the incomplete cell by
increasing a width of the co-plane differential coupling trace or
decreasing a spacing of the co-plane differential coupling trace or
increasing a length of the co-plane differential coupling
trace.
6. The method of claim 1, wherein performing the mutual capacitance
compensation further comprises: modifying a layout pattern of the
incomplete cell and at least one adjacent complete cell adjacent to
the incomplete cell by dividing a small area of the adjacent
complete cell into the incomplete cell.
7. The method of claim 1, wherein performing the mutual capacitance
compensation further comprises: modifying a layout pattern of a
flexible printed circuit (FPC) of the capacitive touch screen
connected to the complete cells and the incomplete cell.
8. The method of claim 7, wherein modifying the layout pattern of
the FPC comprises: increasing an overlap area of at least two
traces of the FPC which are connected to the incomplete cell to
compensate the mutual capacitance of the incomplete cell.
9. The method of claim 1, wherein performing the mutual capacitance
compensation further comprises: modifying a layout pattern of an
evaluation board (EVB) of the capacitive touch screen connected to
the complete cells and the incomplete cell.
10. The method of claim 9, wherein modifying the layout pattern of
the EVB comprises: increasing an overlap area of at least two
traces of the EVB which are connected to the incomplete cell to
compensate the mutual capacitance of the incomplete cell.
Description
BACKGROUND
Field of Invention
[0001] The present invention relates to a method for improving
touch performance. More particularly, the present invention relates
to a method for improving touch performance of a capacitive touch
screen with a non-rectangular shape.
Description of Related Art
[0002] In the existing capacitive touch applications, the touch
sensing methods include a self-capacitive sensing method and a
mutual-capacitive sensing method. In the case of multi-finger touch
applications, the mutual-capacitive sensing method can effectively
improve the ghost point defect of the self-capacitive sensing
method. Therefore, according to different touch environments and
applications, a hybrid sensing method combining the self-capacitive
sensing method and the mutual-capacitive sensing method is used to
achieve the better touch performance.
[0003] It is an important topic to have excellent mutual
capacitance sensing capability in more and more complex touch
applications. Many driving methods have been developed to improve
the signal noise ratio (SNR) of touch performance, such as a
multi-tone mutual mode sensing topology. In order to realize this
special multi-tone sensing driving method, the design and
optimization of the touch pattern becomes an important key
factor.
[0004] Many modern portable products (e.g., the wearable
smart-watch, the headphone, the smart-phone), game sensors
(Joysticks), industrial and medical products require more stylish
and beautiful appearance. At this time, the touch screen is no
longer a complete rectangle shape, but a stylish round, curved and
notch shape design. The above shape design may cause the touch
screen to have incomplete cell and affect the touch performance.
Therefore, the touch performance of the multi-tone drive of the
touch screen with non-rectangular shape will be limited and not has
better SNR.
SUMMARY
[0005] The present invention provides a method for improving touch
performance of a capacitive touch screen with a non-rectangular
shape. The capacitive touch screen includes plural complete cells
and at least one incomplete cell for sensing. The method includes:
determining whether an active area of the incomplete cell is
different from an active area of each of the complete cells; and
performing a mutual capacitance compensation on the incomplete cell
to compensate a mutual capacitance of the incomplete cell when the
active area of the incomplete cell is different from the active
area of each of the complete cells.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The invention 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 an example of a capacitive touch screen with a
non-rectangular shape.
[0008] FIG. 2 is another example of a capacitive touch screen with
the non-rectangular shape.
[0009] FIG. 3 is a flow chart of a method for improving touch
performance of the capacitive touch screen with non-rectangular
shape according to the embodiment of the present invention.
[0010] FIG. 4 is a flow chart of a method for performing the mutual
capacitance compensation according to the embodiment of the present
invention.
[0011] FIG. 5 shows the exemplary modification of the layout
pattern of capacitive touch screen with the corner shape according
to the embodiment of the present invention.
[0012] FIG. 6 shows the exemplary modification of the layout
pattern of capacitive touch screen with the notch shape according
to the embodiment of the present invention.
DETAILED DESCRIPTION
[0013] Specific embodiments of the present invention are further
described in detail below with reference to the accompanying
drawings, however, the embodiments described are not intended to
limit the present invention and it is not intended for the
description of operation to limit the order of implementation.
Moreover, any device with equivalent functions that is produced
from a structure formed by a recombination of elements shall fall
within the scope of the present invention. Additionally, the
drawings are only illustrative and are not drawn to actual
size.
[0014] FIG. 1 is an example of a capacitive touch screen 10 with a
non-rectangular shape (i.e., a corner shape). As shown in FIG. 1,
the capacitive touch screen 10 includes plural complete cells
(i.e., cells B/C/E/F/G/H/I/J/K/L/N/O of FIG. 1) and four incomplete
cells (i.e., cells A/D/M/P of FIG. 1) for sensing. As shown in FIG.
1, the capacitive touch screen 10 includes plural receiver (RX)
electrodes (i.e., RX1.about.RX4) and plural transmit (TX)
electrodes (i.e., TX1.about.TX4). An intersection of one of the RX
electrodes and one of the TX electrodes corresponds to one of the
complete cells or the incomplete cell. For example, the
intersection of RX electrode RX1 and TX electrode TX1 corresponds
to the incomplete cell A. For example, the intersection of RX
electrode RX2 and TX electrode TX2 corresponds to the complete cell
F. FIG. 2 is another example of a capacitive touch screen 20 with
the non-rectangular shape (i.e., a notch shape). As shown in FIG.
2, the capacitive touch screen 20 includes plural complete cells
(i.e., cells A/B/C/D/F/G/H/J/K/L/M/N/O/P of FIG. 2) and two
incomplete cells (i.e., cells E/I of FIG. 2) for sensing.
[0015] As discussed above, both of the capacitive touch screens 10
and 20 include the incomplete cells, and thus the mutual
capacitance of the incomplete cells of the capacitive touch screen
may be insufficient, and thereby causing abnormal multi-tone touch
functionality when the incomplete cells are touched. The present
invention provides a method for improving touch performance of the
capacitive touch screen with non-rectangular shape, e.g., the
capacitive touch screens 10 and 20.
[0016] FIG. 3 is a flow chart of a method 30 for improving touch
performance of the capacitive touch screen with non-rectangular
shape according to the embodiment of the present invention. The
method 30 includes the following steps: determining whether an
active area of the incomplete cell is different from an active area
of each of the complete cells; and performing a mutual capacitance
compensation on the incomplete cell to compensate a mutual
capacitance of the incomplete cell when the active area of the
incomplete cell is different from the active area of each of the
complete cells. For example, as shown in FIG. 1, the active area of
one of the incomplete cells (i.e., cells A/D/M/P of FIG. 1) of the
capacitive touch screen 10 is different from the active area of one
of the complete cells (i.e., cells B/C/E/F/G/H/I/J/K/L/N/O of FIG.
1) of the capacitive touch screen 10. For another example, as shown
in FIG. 2, the active area of one of the incomplete cells (i.e.,
cells E/I of FIG. 2) of the capacitive touch screen 20 is different
from the active area of one of the complete cells (i.e., cells
A/B/C/D/F/G/H/J/K/L/M/N/O/P of FIG. 2) of the capacitive touch
screen 20. In addition, in another embodiment of the present
invention, the mutual capacitance compensation is performed only
when the active area of the incomplete cell is smaller than or
equal to a half of the active area of each of the complete
cells.
[0017] FIG. 4 is a flow chart of a method 40 for performing the
mutual capacitance compensation according to the embodiment of the
present invention. The method 40 includes plural steps 41.about.44.
In step 41, determining whether the incomplete cell has a residual
area. When the incomplete cell has the residual area, a layout
pattern of the incomplete cell is modified to compensate the mutual
capacitance of the incomplete cell, as shown in step 42 of FIG.
4.
[0018] FIG. 5 shows the exemplary modification of the layout
pattern of capacitive touch screen with the corner shape according
to the embodiment of the present invention. As shown in a dotted
box of FIG. 5, an overlap area of the corresponding RX electrode
and the corresponding TX electrode of the incomplete cell is
increased, thereby compensating the mutual capacitance of the
incomplete cell.
[0019] In addition, the mutual capacitance of the incomplete cell
having the residual area may also be compensated by adjusting a
layout pattern of a co-plane differential coupling trace of the
incomplete cell so as to compensate the mutual capacitance of the
incomplete cell. The layout pattern of the co-plane differential
coupling trace of the incomplete cell is adjusted by increasing a
width of the co-plane differential coupling trace or decreasing a
spacing of the co-plane differential coupling trace or increasing a
length of the co-plane differential coupling trace.
[0020] Referring to FIG. 4, after the step 42 is performed,
determining whether the mutual capacitance of the incomplete cell
is insufficient, as shown in step 43 of FIG. 4. When the mutual
capacitance of the incomplete cell is insufficient or the
incomplete cell has no residual area, a layout pattern of the
incomplete cell and the adjacent complete cell is modified to
divide a small area of the adjacent complete cell into the
incomplete cell, and/or a layout pattern of FPC and/or EVB is
modified, as shown in step 44 of FIG. 4, so as to compensate the
mutual capacitance of the incomplete cell.
[0021] FIG. 6 shows the exemplary modification of the layout
pattern of capacitive touch screen with the notch shape according
to the embodiment of the present invention. As shown in a dotted
box of FIG. 6, a layout pattern of the incomplete cells (i.e.,
cells located between TX1 and RX6/RX7) and the adjacent complete
cells (i.e., cell located between TX1 and RX5 and cells located
between TX2 and RX6/RX7) is modified to divide a small area of the
adjacent complete cell into the incomplete cell. It is noted that,
for the adjacent cells, the compensated area divided into the
incomplete cell is a dead zone, so the compensated area cannot be
too big.
[0022] Referring to FIG. 4, in step 44, a layout pattern of a
flexible printed circuit (FPC) of the capacitive touch screen
connected to the complete cells and the incomplete cell may be
modified to compensate the mutual capacitance of the incomplete
cell. The layout pattern of the FPC is modified by increasing an
overlap area of at least two traces of the FPC which are connected
to the incomplete cell to compensate the mutual capacitance of the
incomplete cell.
[0023] Referring to FIG. 4, in step 44, a layout pattern of an
evaluation board (EVB) of the capacitive touch screen connected to
the complete cells and the incomplete cell may be modified to
compensate the mutual capacitance of the incomplete cell. The
layout pattern of the EVB is modified by increasing an overlap area
of at least two traces of the EVB which are connected to the
incomplete cell to compensate the mutual capacitance of the
incomplete cell.
[0024] From the above description, the present invention provides a
method for improving touch performance of the capacitive touch
screen with the non-rectangular shape by compensating the mutual
capacitance of the incomplete cell. Therefore, the touch
performance of the multi-tone drive of the touch screen with
non-rectangular shape is improved and has better SNR in some
special applications (e.g., glove touching, low dielectric constant
of sensor cover layer, thick sensor cover layer).
[0025] Although the present invention 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. It will be apparent to those skilled
in the art that various modifications and variations can be made to
the structure of the present invention without departing from the
scope or spirit of the invention. In view of the foregoing, it is
intended that the present invention cover modifications and
variations of this invention provided they fall within the scope of
the following claims.
* * * * *