U.S. patent application number 15/787834 was filed with the patent office on 2018-02-08 for touch detecting device, display device with touch detecting function, and electronic apparatus.
The applicant listed for this patent is Japan Display Inc.. Invention is credited to Kohei AZUMI, Yoshitoshi KIDA, Hayato KURASAWA.
Application Number | 20180039374 15/787834 |
Document ID | / |
Family ID | 52343202 |
Filed Date | 2018-02-08 |
United States Patent
Application |
20180039374 |
Kind Code |
A1 |
AZUMI; Kohei ; et
al. |
February 8, 2018 |
TOUCH DETECTING DEVICE, DISPLAY DEVICE WITH TOUCH DETECTING
FUNCTION, AND ELECTRONIC APPARATUS
Abstract
According to an aspect, a touch detecting device includes: a
first drive area and a second drive area each including drive
electrodes and detection electrodes, the drive electrodes extending
in a first direction, being arrayed in a second direction
intersecting with the first direction, and being applied with a
drive signal, the detection electrodes extending in the second
direction, being arrayed in the first direction, and outputting a
detection signal. Application of the drive signal to the drive
electrodes in the second drive area is stopped at a timing to apply
the drive signal to the drive electrodes arranged in a first
predetermined area included in the first drive area, and
application of the drive signal to the drive electrodes in the
first drive area is stopped at a timing to apply the drive signal
to a second predetermined area included in the second drive
area.
Inventors: |
AZUMI; Kohei; (Tokyo,
JP) ; KIDA; Yoshitoshi; (Tokyo, JP) ;
KURASAWA; Hayato; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Japan Display Inc. |
Tokyo |
|
JP |
|
|
Family ID: |
52343202 |
Appl. No.: |
15/787834 |
Filed: |
October 19, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15446728 |
Mar 1, 2017 |
9804704 |
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15787834 |
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14335529 |
Jul 18, 2014 |
9619088 |
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15446728 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 3/0445 20190501;
G06F 3/0416 20130101; G06F 3/044 20130101; G06F 2203/04108
20130101; G06F 3/0446 20190501; G06F 2203/04803 20130101; G06F
3/04166 20190501; G06F 3/0412 20130101 |
International
Class: |
G06F 3/041 20060101
G06F003/041; G06F 3/044 20060101 G06F003/044 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 22, 2013 |
JP |
2013-152139 |
Jul 17, 2014 |
JP |
2014-147217 |
Claims
1. A touch detecting device comprising: a first drive area
including a first boundary area and a first non-boundary area; a
second drive area including a second boundary area and a second
non-boundary area, the first boundary area and the second boundary
area being arranged adjacent to each other in a first direction; a
plurality of drive electrodes arranged in the first direction, the
plurality of drive electrodes including first drive electrodes
arranged in the first non-boundary area, and second drive
electrodes arranged in the second non-boundary area; and a
controller configured to supply a drive signal to one of the first
drive electrodes at a same timing of supplying the drive signal to
one of the second drive electrodes, the one of the first drive
electrodes and the one of the second drive electrode being linearly
symmetrical with a boundary line between the first boundary area
and the second boundary area.
2. A touch detecting device according to claim 1, wherein a first
number of the first drive electrodes is the same as a second number
of the second drive electrodes.
3. A touch detecting device according to claim 1, wherein the
controller is configured to supply a drive signal to a third number
of the first drive electrodes at a same timing of supplying the
drive signal to a fourth number of the second drive electrodes, and
the third number and the forth number are same.
4. A touch detecting device according to claim 1, wherein each of
the first drive electrodes and each of the second drive electrodes
are linearly symmetrical with the boundary line, respectively.
5. A touch detecting device according to claim 1, wherein the
controller is configured to: sequentially supply the drive signal
from a first one of the first drive electrodes to a second one of
the first drive electrodes, the second one of the first drive
electrodes being arranged closer to the boundary line than the
first one of the first drive electrodes; and sequentially supply
the drive signal from a first one of the second drive electrodes to
a second one of the second drive electrodes, the second one of the
second drive electrodes being arranged closer to the boundary line
than the first one of the second drive electrodes.
6. A touch detecting device to claim 1, further comprising: a
plurality of detection electrodes extending in the first direction,
the detection electrodes including first detection electrodes and
second detection electrodes, wherein the first detection electrodes
exist from the first non-boundary area to the first boundary area,
and the second detection electrodes exist from the second
non-boundary area to the second boundary area.
7. A touch detecting device according to claim 6, wherein the drive
electrodes extend in a second direction intersecting with the first
direction, and a width of the drive electrodes in the second
direction is larger than a total width of the first detection
electrodes and the second detection electrodes in the first
direction.
8. A touch detecting device according to claim 6, wherein at least
one of the drive electrodes is overlapped with at least one of the
first detection electrodes and at least one of the second detection
electrodes.
9. A touch detecting device according to claim 6, wherein the
controller is configured to not detect at least one of first
detection electrodes at a same timing of detecting at least one of
second detection electrodes.
10. A touch detecting device according to claim 1, wherein the
controller is configured to not supply the drive signal to drive
electrodes that are included in the second boundary area at a same
timing of supplying the drive signal to the first drive electrodes
in the first non-boundary area.
11. A touch detecting device according to claim 1, wherein the
drive electrodes extend in a second direction intersecting with the
first direction, and the controller is arranged adjacent to the
drive electrodes in the second direction.
12. A touch detecting device comprising: a first drive area
including a first boundary area and a first non-boundary area; a
second drive area including a second boundary area and a second
non-boundary area, the first boundary area and the second boundary
area being arranged adjacent to each other in a first direction; a
plurality of drive electrodes arranged in the first direction; and
a controller configured to: supply a drive signal to a fifth number
of the drive electrodes in a non-boundary area that includes the
first non-boundary area and the second non-boundary area; and
supply the drive signal to a sixth number of the drive electrodes
in a boundary area that includes the first boundary area and the
second boundary area, wherein the fifth number is larger than the
sixth number.
13. A touch detecting device according to claim 12, wherein the
drive electrodes include first drive electrodes arranged in the
first non-boundary area, and second drive electrodes arranged in
the second non-boundary area, and wherein the fifth number of the
drive electrodes include at least one of the first drive electrodes
and at least one of the second drive electrodes.
14. A touch detecting device according to claim 12, wherein the
plurality of drive electrodes include first drive electrodes and
second drive electrodes, and one of the first drive electrodes and
the one of the second drive electrode are linearly symmetrical with
a boundary line between the first boundary area and the second
boundary area.
15. A touch detecting device comprising: a first drive area
including a first boundary area and a first non-boundary area; a
second drive area including a second boundary area and a second
non-boundary area, the first boundary area and the second boundary
area being arranged adjacent to each other in a first direction;
and a plurality of drive electrodes arranged in the first
direction, the plurality of drive electrodes including first drive
electrodes arranged in the first non-boundary area, and second
drive electrodes arranged in the second non-boundary area, wherein
one of the first drive electrodes is configured to be supplied with
a drive signal at a same timing of supplying the drive signal to
one of the second drive electrodes, and wherein the one of the
first drive electrodes and the one of the second drive electrodes
are linearly symmetrical with a boundary line between the first
boundary area and the second boundary area.
16. A touch detecting device according to claim 15, wherein a third
number of the first drive electrodes are configured to be supplied
with the drive signal at a timing of supplying the drive signal to
a fourth number of the second drive electrodes, and wherein the
third number and the forth number are same.
17. A touch detecting device according to claim 15, further
comprising: a plurality of detection electrodes extending in the
first direction, the plurality of detection electrodes including
first detection electrodes and second detection electrodes, wherein
the first detection electrodes exist from the first non-boundary
area to the first boundary area, and wherein the second detection
electrodes exist from the second non-boundary area to the second
boundary area.
18. A touch detecting device according to claim 17, wherein at
least one of the drive electrodes is overlapped with at least one
of the first detection electrodes and at least one of the second
detection electrodes.
19. A touch detecting device according to claim 15, wherein at
least one of first detection electrodes is configured to not detect
at a timing of detecting from at least one of second detection
electrodes.
20. A touch detecting device according to claim 15, wherein the
drive electrodes in the second boundary area are configured to not
be supplied with the drive signal at a timing of supplying the
drive signal to the first drive electrodes.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The present application is a continuation application of
U.S. patent application Ser. No. 15/446,728, filed on Mar. 1, 2017,
which application is a continuation application of U.S. patent
application Ser. No. 14/335,529, filed on Jul. 18, 2014, issued as
U.S. Pat. No. 9,619,088 on Apr. 11, 2017, which application claims
priority to Japanese Priority Patent Application JP 2014-147217
filed in the Japan Patent Office on Jul. 17, 2014, and Japanese
Priority Patent Application JP 2013-152139 filed in the Japan
Patent Office on Jul. 22, 2013, the entire content of which is
hereby incorporated by reference.
BACKGROUND
1. Technical Field
[0002] The present application relates to a touch detecting device
capable of detecting an object coming closer thereto from the
outside, a display device with a touch detecting function, and an
electronic apparatus.
2. Description of the Related Art
[0003] Touch detecting devices capable of detecting an object
coming closer thereto from the outside, which are called touch
panels, have been attracting attention in recent years. Such a
touch detecting device is integrated with a display device, for
example. By displaying various types of images or the like for
input on the display device, the touch detecting device is used as
a device for inputting information. Integrating a touch detecting
device with a display device enables input of information without
using an input device, such as a keyboard, a mouse, and a
keypad.
[0004] Some types of technologies for touch detecting devices are
known, including optical, resistive, and capacitive technologies.
Capacitive touch detecting devices have a relatively simple
structure and reduce power consumption. Touch detecting devices are
required to detect approach or contact of an object as reliably as
possible. Such a touch detecting device is described in Japanese
Patent Application Laid-open Publication No. 2007-172028, for
example.
[0005] In touch detecting devices, the detection sensitivity and
the position detection accuracy have a trade-off relation with the
detection speed (report rate). To increase the detection
sensitivity, it is necessary to provide as many detection circuits
as possible. To increase the position detection accuracy, it is
necessary to provide as many electrodes as possible. Providing many
detection circuits and electrodes may possibly increase a detection
time and a drive time, thereby decreasing the detection speed.
[0006] For the foregoing reasons, there is a need for a touch
detecting device, a display device with a touch detecting function,
and an electronic apparatus that can maintain excellent detection
sensitivity and excellent position detection accuracy in touch
detection and increase the detection speed.
SUMMARY
[0007] According to an aspect, a touch detecting device includes: a
first drive area and a second drive area each including a plurality
of drive electrodes and a plurality of detection electrodes, the
plurality of drive electrodes extending in a first direction, being
arrayed in a second direction intersecting with the first
direction, and being applied with a drive signal serving as a
signal for detecting at least one of approach and contact of an
object, the plurality of detection electrodes extending in the
second direction, being arrayed in the first direction, and
outputting a detection signal serving as a signal corresponding to
a change in capacitance generated between the detection electrodes
and the drive electrodes, the first drive area and the second drive
area being arranged adjacent to each other in the second direction;
a boundary between the first drive area and the second drive area
adjacent to each other; and a first predetermined area included in
the first drive area and a second predetermined area included in
the second drive area. The first predetermined area and the second
predetermined area face each other with the boundary interposed
therebetween, and application of the drive signal to the drive
electrodes arranged in the second drive area is stopped at a timing
to apply the drive signal to the drive electrodes arranged in the
first predetermined area, and application of the drive signal to
the drive electrodes arranged in the first drive area is stopped at
a timing to apply the drive signal to the second predetermined
area.
[0008] According to another aspect, a display apparatus with a
touch detecting function includes a touch detecting device. The
touch detecting device includes: a first drive area and a second
drive area each including a plurality of drive electrodes and a
plurality of detection electrodes, the plurality of drive
electrodes extending in a first direction, being arrayed in a
second direction intersecting with the first direction, and being
applied with a drive signal serving as a signal for detecting at
least one of approach and contact of an object, the plurality of
detection electrodes extending in the second direction, being
arrayed in the first direction, and outputting a detection signal
serving as a signal corresponding to a change in capacitance
generated between the detection electrodes and the drive
electrodes, the first drive area and the second drive area being
arranged adjacent to each other in the second direction; a boundary
between the first drive area and the second drive area adjacent to
each other; and a first predetermined area included in the first
drive area and a second predetermined area included in the second
drive area; and a display device integrated with the touch
detecting device. The first predetermined area and the second
predetermined area face each other with the boundary interposed
therebetween, and a direction of display scanning performed by the
display device is different from a direction of touch detection
scanning performed by the touch detecting device.
[0009] Additional features and advantages are described herein, and
will be apparent from the following Detailed Description and the
figures.
BRIEF DESCRIPTION OF THE FIGURES
[0010] FIG. 1 is a schematic of a touch detecting device according
to a first embodiment;
[0011] FIG. 2 is an exploded perspective view of the touch
detecting device according to the embodiment;
[0012] FIG. 3 is a view for explaining the basic principle of a
capacitive touch detection technology and illustrates a state where
no finger is in contact or in contiguity with the touch detecting
device;
[0013] FIG. 4 is a view for explaining an example of an equivalent
circuit in the state where no finger is in contact or in contiguity
with the touch detecting device as illustrated in FIG. 3;
[0014] FIG. 5 is a view for explaining the basic principle of
detection of a touch operation and illustrates a state where a
finger is in contact or in contiguity with the touch detecting
device;
[0015] FIG. 6 is a view for explaining an example of the equivalent
circuit in the state where a finger is in contact or in contiguity
with the touch detecting device as illustrated in FIG. 5;
[0016] FIG. 7 is a diagram of an example of waveforms of a signal
for detecting a touch and a touch detection signal;
[0017] FIG. 8A is a schematic of an example of an interference
portion of the touch detecting device according to the first
embodiment;
[0018] FIG. 8B is a schematic of another example of the
interference portion of the touch detecting device according to the
first embodiment;
[0019] FIG. 9 is a diagram illustrating a driving order of blocks
of drive electrodes;
[0020] FIG. 10 is a schematic of a state where the interference
portion of one drive area is driven out of drive areas of the touch
detecting device according to the first embodiment;
[0021] FIG. 11 is a schematic of a state where the interference
portion of the other drive area is driven out of the drive areas of
the touch detecting device according to the first embodiment;
[0022] FIG. 12 is a schematic of a state where a plurality of
blocks are simultaneously driven in a touch detecting device
according to a second embodiment;
[0023] FIG. 13 is a schematic of a state where a plurality of
blocks are simultaneously driven in the touch detecting device
according to the second embodiment;
[0024] FIG. 14 is a schematic of a touch detecting device according
to a third embodiment;
[0025] FIG. 15 is a schematic of a touch detecting device according
to a fourth embodiment;
[0026] FIG. 16 is a schematic of a touch detecting device according
to a fifth embodiment;
[0027] FIG. 17 is a schematic of the touch detecting device
according to the fifth embodiment;
[0028] FIG. 18 is a block diagram of a display device with a touch
detecting function according to a sixth embodiment;
[0029] FIG. 19 is a schematic of an example of a module on which
the display device with a touch detecting function is mounted;
[0030] FIG. 20 is a schematic of another example of the module on
which the display device with a touch detecting function is
mounted;
[0031] FIG. 21 is a sectional view of a schematic sectional
structure of a display device with a touch detecting function;
[0032] FIG. 22 is a circuit diagram of a pixel array in the display
device with a touch detecting function;
[0033] FIG. 23 is a timing waveform chart of an exemplary operation
of the display device with a touch detecting function according to
the sixth embodiment;
[0034] FIG. 24 is a schematic of an example of a module on which a
display device with a touch detecting function according to a
modification is mounted;
[0035] FIG. 25 is a schematic of an example of an electronic
apparatus to which the touch detecting device according to the
present application is applied;
[0036] FIG. 26 is a schematic of an example of an electronic
apparatus to which the touch detecting device according to the
present application is applied;
[0037] FIG. 27 is a schematic of an example of an electronic
apparatus to which the touch detecting device according to the
present application is applied;
[0038] FIG. 28 is a schematic of an example of an electronic
apparatus to which the touch detecting device according to the
present application is applied;
[0039] FIG. 29 is a schematic of an example of an electronic
apparatus to which the touch detecting device according to the
present application is applied;
[0040] FIG. 30 is a schematic of an example of an electronic
apparatus to which the touch detecting device according to the
present application is applied; and
[0041] FIG. 31 is a schematic of an example of an electronic
apparatus to which the touch detecting device according to the
present application is applied.
DETAILED DESCRIPTION
[0042] Exemplary aspects (embodiments) according to the present
application are described in greater detail with reference to the
accompanying drawings in the following order.
[0043] 1. Embodiments [0044] 1-1. First embodiment [0045] 1-2.
Second embodiment [0046] 1-3. Third embodiment [0047] 1-4. Fourth
embodiment [0048] 1-5. Fifth embodiment [0049] 1-6. Sixth
embodiment
[0050] 2. Application examples
[0051] 3. Aspects of the present application
1. Embodiments
1-1. First Embodiment
[0052] FIG. 1 is a schematic of a touch detecting device according
to a first embodiment. FIG. 2 is an exploded perspective view of
the touch detecting device according to the embodiment. A touch
detecting device 1 is what is called a capacitive touch detecting
device. The touch detecting device 1 includes a plurality of drive
electrodes COML and a plurality of touch detection electrodes TDL.
The touch detection electrodes TDL are provided in a manner
intersecting (including a grade separated intersection) with the
drive electrodes COML. The drive electrodes COML are arranged on a
plane. The touch detection electrodes TDL are arranged on a plane
different from the plane on which the drive electrodes COML are
arranged. The plane on which the drive electrodes COML are arranged
and a plane parallel to the plane on which the drive electrodes
COML are arranged are referred to as an X-Y plane. The X-Y plane is
defined by the X-axis and the Y-axis, which are the coordinate
axes. The X-axis and the Y-axis are orthogonal to each other. An
axis orthogonal to the X-axis and the Y-axis is the Z-axis.
[0053] The drive electrodes COML extend in a first direction (the
X-axis direction in the present embodiment) and are arrayed in a
second direction (the Y-axis direction in the present embodiment)
intersecting with the first direction. The drive electrodes COML
are supplied with a drive signal Vcom serving as a signal for
detecting at least one of approach and contact of an object. The
drive signal Vcom is applied by a driving unit 53 electrically
coupled to each of the drive electrodes COML. The driving unit 53
is controlled by a control unit 11. In the present embodiment, the
first direction and the second direction are orthogonal to each
other. These directions are not necessarily orthogonal to each
other, and they simply need to intersect with each other.
[0054] The touch detection electrodes TDL extend in the second
direction (the Y-axis direction in the present embodiment) and are
arrayed in the first direction (the X-axis direction in the present
embodiment). The touch detection electrodes TDL intersect with the
drive electrodes COML with a predetermined gap interposed
therebetween, that is, intersect with the drive electrodes COML in
a grade separated manner. The touch detection electrodes TDL output
a detection signal (hereinafter referred to as a touch detection
signal) Vdet as a signal corresponding to a change in capacitance
generated between the touch detection electrodes TDL and the drive
electrodes COML. The first direction is hereinafter referred to as
an X-direction, and the second direction is referred to as a
Y-direction as needed.
[0055] In the present embodiment, the drive electrodes COML and the
touch detection electrodes TDL each have a rectangular shape in a
planar view, that is, viewed from the Z-axis direction. The drive
electrodes COML have a larger dimension in the X-direction than
that in the Y-direction. The touch detection electrodes TDL have a
larger dimension in the Y-direction than that in the X-direction.
The shapes of the drive electrodes COML and the touch detection
electrodes TDL are not limited to a rectangle.
[0056] The capacitance is generated at portions where the drive
electrodes COML and the touch detection electrodes TDL intersect
with each other. The touch detection electrodes TDL are
electrically coupled to an input unit of a touch detection
processing unit 40. While the touch detection processing unit 40 is
divided into two in FIG. 1 for convenience of the explanation, the
number of touch detecting units 40 may be one or a plurality. The
touch detection processing unit 40 is controlled by the control
unit 11. A change in the capacitance at portions where the touch
detection electrodes TDL and the drive electrodes COML intersect
with each other is input to the touch detection processing unit 40
as the touch detection signal Vdet. Based on the touch detection
signal Vdet, the touch detection processing unit 40 detects a
portion where the capacitance changes out of the portions where the
drive electrodes COML and the touch detection electrodes TDL
intersect with each other. Based on the touch detection signal
Vdet, the touch detection processing unit 40 identifies a position
at which the object is in contact or in contiguity with the touch
detecting device 1. Contact or contiguity of the object with the
touch detecting device 1 is hereinafter referred to as a touch as
needed.
[0057] In the present embodiment, the drive electrodes COML and the
touch detection electrodes TDL intersect with each other in a grade
separated manner. A touch is detected based on a change in the
capacitance generated at a portion where the electrodes face each
other. The position at which the capacitance is generated, however,
is not limited to the portion where the electrodes face each other.
In the touch detecting device 1, for example, conductors extracted
from the drive electrodes COML and conductors extracted from the
touch detection electrodes TDL may be arranged in a single plane to
detect a touch based on capacitance generated between the
conductors. In other words, the touch detecting device 1 simply
needs to detect a touch based on the capacitance generated between
the drive electrodes COML and the touch detection electrodes TDL.
The following describes an example of the basic principle in that
the touch detecting device 1 detects a touch.
[0058] Basic Principle of Capacitive Touch Detection
[0059] FIG. 3 is a view for explaining the basic principle of a
capacitive touch detection technology and illustrates a state where
no finger is in contact or in contiguity with the touch detecting
device. FIG. 4 is a view for explaining an example of an equivalent
circuit in the state where a finger is in contact or in contiguity
with the touch detecting device as illustrated in FIG. 3. FIG. 5 is
a view for explaining the basic principle of detection of a touch
operation and illustrates a state where a finger is in contact or
in contiguity with the touch detecting device. FIG. 6 is a view for
explaining an example of the equivalent circuit in the state where
a finger is in contact or in contiguity with the touch detecting
device as illustrated in FIG. 5. FIG. 7 is a diagram of an example
of waveforms of a signal for detecting a touch and a touch
detection signal. A touch detecting unit 30 operates based on the
basic principle of capacitive touch detection and outputs the touch
detection signal Vdet. The following describes the basic principle
of touch detection performed by the display device 1 with a touch
detecting function according to the present embodiment with
reference to FIG. 1 to FIG. 6.
[0060] As illustrated in FIG. 3 and FIG. 5, a capacitive element C1
includes a pair of electrodes of a drive electrode E1 and a touch
detection electrode E2 arranged in a manner facing each other with
a dielectric D interposed therebetween, for example. As illustrated
in FIG. 4 and FIG. 6, one end of the capacitive element C1 is
coupled to an alternating-current (AC) signal source (a drive
signal source) S, whereas the other end is coupled to a voltage
detector (a touch detection processing unit) DET. The voltage
detector DET is an integration circuit, for example.
[0061] When the AC signal source S applies an alternating-current
(AC) rectangular wave Sg at a predetermined frequency (e.g.,
approximately several kilohertz to several hundred kilohertz) to
the drive electrode E1 (the one end of the capacitive element C1),
an output waveform (touch detection signal Vdet) is generated via
the voltage detector DET coupled to the touch detection electrode
E2 (the other end of the capacitive element C1). The AC rectangular
wave Sg corresponds to a touch drive signal Vcomt, which will be
described later.
[0062] When no finger is in contact (or in contiguity) with the
device (a non-contact state), an electric current I.sub.0 depending
on the capacitance value of the capacitive element C1 flows in
association with charge and discharge to the capacitive element C1
as illustrated in FIG. 3 and FIG. 4. As illustrated in FIG. 7, the
voltage detector DET converts fluctuations in the electric current
I.sub.0 depending on the AC rectangular wave Sg into fluctuations
in the voltage (a waveform V.sub.0 indicated by a solid line).
[0063] By contrast, when a finger is in contact (or in contiguity)
with the device (a contact state), capacitance C2 generated by the
finger is in contact or in contiguity with the touch detection
electrode E2 as illustrated in FIG. 5. This blocks capacitance of a
fringe between the drive electrode E1 and the touch detection
electrode E2, thereby providing a capacitive element C1' having a
capacitance value smaller than that of the capacitive element C1.
In the equivalent circuit illustrated in FIG. 6, an electric
current I.sub.1 flows through the capacitive element C1'. As
illustrated in FIG. 7, the voltage detector DET converts
fluctuations in the electric current I.sub.1 depending on the AC
rectangular wave Sg into fluctuations in the voltage (a waveform
V.sub.1 indicated by a dotted line). In this case, the waveform
V.sub.1 has amplitude smaller than that of the waveform V.sub.0.
Thus, an absolute value |.DELTA.V| of the voltage difference
between the waveform V.sub.0 and the waveform V.sub.1 varies
depending on an influence of the object, such as a finger,
approaching the device from the outside. To detect the absolute
value |.DELTA.V| of the voltage difference between the waveform
V.sub.0 and the waveform V.sub.1 with high accuracy, the voltage
detector DET preferably operates with a period RESET to reset
charge and discharge of a capacitor based on the frequency of the
AC rectangular wave Sg by switching in the circuit. The basic
principle in that the touch detecting device 1 detects a touch is
not limited to that described above.
[0064] The touch detecting unit 30 illustrated in FIG. 18
sequentially scans each detection block or scans a plurality of
detection blocks at a time in response to the drive signal Vcom
(touch drive signal Vcomt, which will be described later) supplied
from a drive electrode driver 14, thereby performing touch
detection.
[0065] The touch detecting unit 30 outputs the touch detection
signal Vdet for each detection block from the touch detection
electrodes TDL, which will be described later, via the voltage
detector DET illustrated in FIG. 4 or FIG. 6, thereby supplying the
touch detection signal Vdet to an analog low-pass filter (LPF) 42
of the touch detection processing unit 40.
[0066] An analog/digital (A/D) converter 43 is a circuit that
samples an analog signal output from the analog low-pass filter
(LPF) 42 at a timing synchronized with the drive signal Vcom,
thereby converting the analog signal into a digital signal.
[0067] A signal processing unit 44 includes a digital filter that
reduces frequency components (noise components) other than the
frequency at which the drive signal Vcom is sampled in the output
signal from the A/D converter 43. The signal processing unit 44 is
a logic circuit that detects whether a touch is made on the touch
detecting unit 30 based on the output signal from the A/D converter
43. The signal processing unit 44 performs processing for
extracting only the voltage difference caused by the finger. The
voltage difference caused by the finger corresponds to the absolute
value |.DELTA.V| of the difference between the waveform V.sub.0 and
the waveform V.sub.1. The signal processing unit 44 may perform an
arithmetic operation for averaging the absolute value |.DELTA.V|
per detection block, thereby deriving the average value of the
absolute value |.DELTA.V|. Thus, the signal processing unit 44 can
reduce an influence caused by noise. The signal processing unit 44
compares the detected voltage difference caused by the finger with
a predetermined threshold voltage. If the voltage difference is
equal to or larger than the threshold voltage, the signal
processing unit 44 determines that an external contiguous object
approaching the device from the outside is in contact with the
device. If the voltage difference is smaller than the threshold
voltage, the signal processing unit 44 determines that the external
contiguous object is not in contact with the device. Thus, the
touch detection processing unit 40 performs touch detection.
[0068] A coordinate extracting unit 45 is a logic circuit that
derives, when a touch is detected by the signal processing unit 44,
the touch panel coordinates of the touch. A detection timing
control unit 46 performs control such that the A/D converter 43,
the signal processing unit 44, and the coordinate extracting unit
45 operate in synchronization with one another. The coordinate
extracting unit 45 outputs the touch panel coordinates as a signal
output Vout.
[0069] The following describes a plurality of drive areas L and R
included in the touch detecting device 1. While the touch detecting
device 1 includes two drive areas L and R in the present
embodiment, the number of drive areas is not limited to two. The
drive areas L and R each include the drive electrodes COML and the
touch detection electrodes TDL. The drive area L includes a
plurality of drive electrodes COML represented by reference
characters L0 to Lm (m is an integer). The drive area R includes a
plurality of drive electrodes COML represented by reference
characters R0 to Rn (n is an integer). The drive electrodes COML
are hereinafter referred to as blocks L0 to Lm and R0 to Rn as
needed. The numbers of the drive areas L and R and the touch
detection electrodes TDL are not restricted.
[0070] The drive areas L and R are arranged side by side in the
Y-direction. The drive area L and the drive area R are divided by a
boundary 65. The boundary 65 corresponds to a portion between a
block L11 arranged at a part of the drive area L adjacent to the
drive area R and a block R11 arranged at a part of the drive area R
adjacent to the drive area L. The drive areas L and R are
individually driven by the control unit 11. The control unit 11
applies the drive signal Vcom to the drive areas L and R separately
and individually via the driving unit 53. The control unit 11
drives the blocks L0 to Lm of the drive electrodes COML arranged in
the drive areas L and the blocks R0 to Rn of the drive electrodes
COML arranged in the drive areas R individually in the drive areas
L and R. The control unit 11, for example, sequentially applies the
drive signal Vcom from the block L0 to the block L11 of the drive
area L via the driving unit 53 and sequentially applies the drive
signal Vcom from the block R0 to the block R11 of the drive area R
via the driving unit 53. At this time, the control unit 11 applies
the drive signal Vcom simultaneously to the block L0 of the drive
area L and the block R0 of the drive area R.
[0071] To detect a touch, the touch detecting device 1 sequentially
drives the blocks R0 to Rn of the drive area R and the blocks L0 to
Lm of the drive area L. If the control unit 11 applies the drive
signal Vcom to a block near the boundary 65 between the drive area
R and the drive area L (e.g., the blocks Lm and Rm, which are
hereinafter referred to as the blocks L11 and R11, respectively, as
needed), electric fields of the blocks (the blocks L11 and R11 in
this example) near the boundary 65 between the drive area R and the
drive area L may possibly cross the boundary 65 between the drive
area R and the drive area L as indicated by the arrows in FIG. 1.
As a result, it may possibly be difficult for the touch detection
processing unit 40 and the control unit 11 to identify to which
block of the drive electrodes COML the touch detection signal Vdet
corresponds.
[0072] When the control unit 11 drives the block R11 of the drive
area R and the block L11 of the drive area L illustrated in FIG. 1,
for example, the electric field generated by the block R11 affects
the block R10 of the drive area R and the block L11 of the drive
area L adjacent to the drive area R as indicated by the arrows in
FIG. 1. When the touch detection processing unit 40 and the control
unit 11 detect a touch at the block L11, the influence of the
electric field generated by the block R11 adjacent to the block L11
may possibly cause the touch detection electrodes TDL of the drive
area L to output a signal even though no touch is made at the block
L11. The touch detection processing unit 40 and the control unit 11
receive the signal and may possibly determine that a touch is made
at the block L11 even though no touch is made at the block L11. As
described above, the touch detecting device 1 drives two drive
areas L and R individually and detects a touch simultaneously in
the two drive areas L and R. When a touch is detected at the blocks
L11 and R11 arranged near the boundary 65, for example, it is
difficult to identify whether the detected touch means a change in
the capacitance of the drive area L or the drive area R. This may
possibly result in false detection of the touch. The same situation
occurs in the case where the drive signal Vcom is applied to the
block L11 of the drive area L illustrated in FIG. 1.
[0073] The touch detecting device 1 includes an interference
portion 66 formed of drive electrodes COML that are arranged near
the boundary 65 between the drive area (a first drive area) L and
the drive area (a second drive area) R and affected by electric
fields of other drive electrodes COML. Drive electrodes COML not
included in the interference portion 66 are referred to as
independent portions 67L and 67R. The interference portion 66 is a
predetermined area extending in the Y-direction, which is the
second direction, from the boundary 65 between the drive areas L
and R adjacent to each other. In other words, the interference
portion 66 is arranged both in the drive areas L and R. The
interference portion 66 in the drive area L corresponds to a first
predetermined area, whereas the interference portion 66 in the
drive area R corresponds to a second predetermined area. The
interference portion 66 in the drive area L and the interference
portion 66 in the drive area R face each other with the boundary 65
interposed therebetween.
[0074] In the touch detecting device 1 of the example illustrated
in FIG. 1, the interference portion 66 is formed of six drive
electrodes COML arranged in a predetermined range in the drive area
R and a predetermined range in the drive area L with respect to the
boundary 65 between the drive areas L and R. Specifically, in the
touch detecting device 1, out of the drive electrodes COML of the
drive area R, three blocks of the block R9 to the block R11
positioned near the boundary 65 are the interference portion 66,
and the block R0 to the block R8 are the independent portion 67R.
Similarly, in the touch detecting device 1, out of the drive
electrodes COML of the drive area L, three blocks of the block L9
to the block L11 positioned near the boundary 65 are the
interference portion 66, and the block L0 to the block L8 are the
independent portion 67L.
[0075] In the touch detecting device 1 in this example, six drive
electrodes COML with respect to the boundary 65 between the drive
areas L and R, that is, three drive electrodes COML in each of the
drive areas L and R are defined as the interference portion 66. The
range of the interference portion 66 in the Y-direction is
determined depending on the range affected by the electric fields
of the drive electrodes COML near the boundary 65. When the drive
signal Vcom is applied to a drive electrode COML near the boundary
65, for example, an electric field is generated by the drive
electrode COML to which the drive signal Vcom is applied. The range
in which the electric field crosses the boundary 65 and affects the
adjacent drive area may be the range of the interference portion 66
in the Y-direction. The range in which the electric field generated
by the drive electrode COML affects the adjacent drive area may be
a range in which a signal caused by the electric field generated by
the drive electrode COML and mixed with a touch detection signal
Vdet output from a touch detection electrode TDL arranged in the
adjacent drive area prevents the touch detection processing unit 40
and the control unit 11 from detecting the touch detection signal
Vdet corresponding to a touch, for example. The range in which the
electric field generated by the drive electrode COML affects the
adjacent drive area may be a range of two drive electrodes COML in
a direction away from the boundary 65 in the Y-direction in each of
the drive areas L and R with respect to the boundary 65, for
example.
[0076] FIG. 8A is a schematic of an example of the interference
portion of the touch detecting device according to the first
embodiment. FIG. 8B is a schematic of another example of the
interference portion of the touch detecting device according to the
first embodiment. The interference portion 66 simply needs to have
a dimension of equal to or larger than one-half of that of the
drive electrodes COML in the Y-direction, which is the second
direction, in one drive area. As illustrated in FIG. 8A, for
example, two drive electrodes COML arranged in a direction away
from the boundary 65 in the Y-direction in each of the drive areas
L and R with respect to the boundary 65 may be defined as the
interference portion 66. Alternatively, as illustrated in FIG. 8B,
1.5 drive electrodes COML arranged in the direction away from the
boundary 65 in the Y-direction in each of the drive areas L and R
with respect to the boundary 65 may be defined as the interference
portion 66, for example. When collectively driving a plurality of
drive electrodes COML, the interference portion 66 simply needs to
have a dimension of equal to or larger than one-half of the
dimension in the Y-direction of the drive electrodes COML that are
simultaneously driven.
[0077] The drive areas L and R preferably have the same size (same
area). The boundary 65 between the drive areas L and R is
preferably parallel to the blocks L0 to Lm and the blocks R0 to Rn
or orthogonal to the touch detection electrodes TDL. By making the
drive areas L and R the same in size and making the boundary 65
parallel to the blocks L0 to Lm and the blocks R0 to Rn or
orthogonal to the touch detection electrodes TDL, the circuit of
the touch detecting device 1 can be designed to have a symmetrical
configuration with respect to the boundary 65. This enables
rational designing of the touch detecting device 1.
[0078] In the drive areas L and R adjacent to each other, the touch
detection electrodes TDL belonging to each of the drive areas L and
R are preferably arranged at the same position in the Y-direction,
which is the second direction, on the boundary 65 side. Thereby,
when the interference portion 66 corresponds to a range of a
certain distance from the touch detection electrodes TDL, it is
possible to make the interference portion 66 the smallest and make
the independent portions 67L and 67R the largest. It is possible to
increase the report rate most efficiently. The following describes
an operation of the touch detecting device 1.
[0079] FIG. 9 is a diagram illustrating a driving order of the
blocks of the drive electrodes. FIG. 10 is a schematic of a state
where the interference portion of one drive area is driven out of
the drive areas of the touch detecting device according to the
first embodiment. FIG. 11 is a schematic of a state where the
interference portion of the other drive area is driven out of the
drive areas of the touch detecting device according to the first
embodiment. In the present embodiment, the control unit 11 applies
the drive signal Vcom to the drive electrodes COML arranged in the
interference portion 66 in the Y-direction from the boundary 65
between the drive areas L and R adjacent to each other. At this
timing, the control unit 11 stops application of the drive signal
Vcom to drive electrodes COML that are arranged in the drive area
adjacent to the interference portion 66 out of the drive areas L
and R and are not included in the drive electrodes COML to which
the drive signal Vcom is applied. The following describes the
operation more specifically.
[0080] In the touch detecting device 1 illustrated in FIG. 1, the
blocks R0 to R8 of the drive area R serve as the independent
portion 67R, and the blocks R9 to R11 serve as the interference
portion 66. The blocks L0 to L8 of the drive area L serve as the
independent portion 67L, and the blocks L9 to L11 serve as the
interference portion 66. To detect a touch, the control unit 11
drives, that is, applies the drive signal Vcom to the blocks R0 to
R8 arranged in the independent portion 67R of the drive area R and
the blocks L0 to L8 arranged in the independent portion 67L of the
drive area L in the order illustrated in FIG. 9.
[0081] When it is time to drive the blocks (the blocks L9 to L11 in
the present embodiment) of the interference portion 66 in the drive
area L, for example, the control unit 11 stops driving, that is,
stops application of the drive signal Vcom to all the blocks (the
blocks R0 to Rn in the present embodiment) arranged in the drive
area R adjacent to the interference portion 66 in the drive area L.
The touch detecting device 1 stops driving the drive area R, that
is, stops application of the drive signal Vcom to all the drive
electrodes COML included in the drive area R. Subsequently, the
touch detecting device 1 drives the blocks L9, L10, and L11 of the
interference portion 66 in the drive area L in this order as
illustrated in FIG. 10.
[0082] This operation drives the blocks L9 to L11 of the
interference portion 66 in the drive area L alone while stopping
the driving of the drive area R at the timing to drive the blocks
L9 to L11 of the interference portion 66 in the drive area L. When
the driving of the blocks L9 to L11 serving as the interference
portion 66 in the drive area L is completed, the control unit 11
and the driving unit 53 drive the blocks R9 to R11 arranged in the
interference portion 66 in the drive area R of which driving has
been stopped as illustrated in FIG. 11. After the blocks L0 to Lm
of the independent portion 67L and the interference portion 66 in
the drive area L and the blocks R0 to Rn of the independent portion
67R and the interference portion 66 in the drive area R are driven,
the control unit 11 sequentially drives the blocks from the block
L0 of the independent portion 67L in the drive area L and the block
R0 of the independent portion 67R in the drive area R.
[0083] In this example, the control unit 11 drives the blocks L0 to
L8 of the independent portion 67L in the drive area L and the
blocks R0 to R8 of the independent portion 67R in the drive area R
in parallel. Subsequently, the control unit 11 drives the blocks L9
to L11 of the interference portion 66 in the drive area L and then
drives the blocks R9 to R11. The driving order is not limited
thereto. The control unit 11 may drive the blocks R9 to R11 of the
interference portion 66 in the drive area R and then drive the
blocks L9 to L11 of the interference portion 66 in the drive area
L.
[0084] As described above, to drive the independent portions 67L
and 67R, the control unit 11 drives the blocks L0 to Lm in the
drive area L and the blocks R0 to Rn in the drive area R
separately. At a timing to drive blocks arranged in the
interference portion 66 in one of drive areas, the control unit 11
stops driving the blocks arranged in the other of drive areas.
After the driving of the blocks arranged in the interference
portion 66 in the one drive area, the touch detecting device 1
drives blocks arranged in the interference portion 66 in the other
drive area. Even when the blocks of the interference portion 66
adjacent to the boundary 65 between the drive areas L and R in one
drive area are driven and the electric fields of the driven blocks
cross the boundary 65, the touch detecting device 1 can make the
electric fields less likely to affect a touch detection operation
on the other drive area because the driving of the other drive area
is stopped. Thus, the touch detecting device 1 can accurately
identify the position of the driven block and at which the value of
the capacitance changes, thereby detecting the position of the
touch. Because the touch detecting device 1 drives the blocks of
the independent portions 67L and 67R in the drive areas L and R in
parallel, the touch detecting device 1 can complete driving of all
the blocks at high speed even when the blocks are sequentially
driven in a time division manner. This can increase the report rate
in touch detection.
[0085] In the present embodiment, when outputs OUT_L and OUT_R are
supplied from the touch detection electrodes TDL of the drive areas
L and R for the blocks L0 to L8 and R0 to R8 corresponding to the
independent portions 67L and 67R of the drive areas L and R,
respectively, as illustrated in FIG. 9, the control unit 11 uses
these outputs OUT_L and OUT_R as the touch detection signal Vdet in
the drive areas L and R, respectively. When driving the blocks L9
to L11 arranged in the interference portion 66 in the drive area L,
the control unit 11 uses a value obtained by combining the output
OUT_L from the touch detection electrodes TDL of the drive area L
and the output OUT_R from the touch detection electrodes TDL of the
drive area R as the touch detection signal Vdet. Similarly, when
driving the blocks R9 to R11 arranged in the interference portion
66 in the drive area R, the control unit 11 uses a value obtained
by combining the output from the touch detection electrodes TDL of
the drive area R and the output from the touch detection electrodes
TDL of the drive area L as the touch detection signal Vdet. This
can cancel out the influence of the electric field generated by the
drive electrode COML to which the drive signal Vcom is applied,
thereby improving the detection accuracy of a touch.
[0086] When the drive electrodes COML of the interference portion
66 are driven, the touch detecting device 1 adds the output from
the touch detection electrodes TDL in the adjacent area, thereby
detecting the electric field generated by the drive electrodes COML
of the interference portion and affecting the touch detection
electrodes TDL in the adjacent drive area. This can increase the
accuracy and the sensitivity in detection. When a drive electrode
COML in the independent area is driven, it is not necessary to add
the output from the touch detection electrodes TDL because the
influence of the electric field on the touch detection electrodes
COML in the adjacent area is negligibly small.
[0087] By combining the output from the touch detection electrodes
TDL in the drive area L and the output from the touch detection
electrodes TDL in the drive area R when the drive electrodes COML
of the interference portion are driven, the advantages described
above are provided. The outputs are not necessarily combined in the
present embodiment. When the drive electrodes COML of the
interference area in the drive area L are driven, the output from
the touch detection electrodes TDL in the drive area L alone may be
detected. When the drive electrodes COML of the interference area
in the drive area R are driven, the output from the touch detection
electrodes TDL in the drive area R alone may be detected.
[0088] By incorporating the touch detecting device 1 into a
liquid-crystal display device, an in-cell display device with a
touch detecting function is provided. The in-cell display device
with a touch detecting function needs to have a display period and
a touch detection period separately in a predetermined period, such
as one horizontal period or one vertical period, to perform
operations. As a result, the in-cell display device with a touch
detecting function may possibly have a lower report rate in touch
detection. By contrast, the touch detecting device 1 according to
the present embodiment can complete driving of all the blocks at
high speed by driving the blocks in the drive areas L and R in
parallel. Thus, an in-cell display device with a touch detecting
function to which the touch detecting device 1 is applied can
increase the report rate in touch detection.
1-2. Second Embodiment
[0089] A touch detecting device 1 according to a second embodiment
will be described. The touch detecting device 1 according to the
first embodiment drives only one block simultaneously in the drive
area L or the drive area R both in the driving of the blocks of the
independent portions 67L and 67R in the drive areas L and R,
respectively, and the driving of the blocks of the interference
portion 66. In a touch detecting device 1A according to the second
embodiment, a control unit 11 simultaneously applies drive signals
Vcom to at least two of a plurality of drive electrodes COML in at
least one drive area out of drive areas L and R, thereby
simultaneously driving a plurality of blocks. The touch detecting
device 1A according to the second embodiment is different from the
touch detecting device 1 according to the first embodiment only in
this respect. The following describes only the difference, and an
overlapping explanation is omitted.
[0090] FIGS. 12 and 13 are schematics of a state where a plurality
of blocks are simultaneously driven in the touch detecting device
1A according to the second embodiment. In FIGS. 12 and 13, blocks
being driven are indicated by the hatched lines. To drive blocks of
independent portion 67R in the drive area R, the touch detecting
device 1A (specifically, the control unit 11) applies a drive
signal Vcom to each drive electrode COML, thereby sequentially
driving one block at a time in the drive area R in order of a block
R0, a block R1, a block R2, . . . , for example, as illustrated in
FIG. 12. To drive the blocks of the independent portion 67L in the
drive area L, the touch detecting device 1A applies the drive
signal Vcom to two drive electrodes COML at a time, thereby
sequentially driving two blocks at a time in the drive area L in
order of a block L0 and a block L1, a block L2 and a block L3, a
block L4 and a block L5, . . . , for example.
[0091] Thus, the touch detecting device 1A can increase the number
of blocks being driven in the drive area L, thereby further
increasing the report rate and the sensitivity in touch detection.
While the control unit 11 drives two blocks at a time in the drive
area L in the present embodiment, the control unit 11 may drive two
blocks at a time in the drive area R. Alternatively, the control
unit 11 may drive three or four blocks at a time in the drive area
L, for example. Still alternatively, the control unit 11 may drive
a plurality of blocks at a time in each of the drive area L and the
drive area R. In these cases as well, the touch detecting device 1A
can further increase the report rate and the sensitivity in touch
detection.
[0092] The touch detecting device 1A drives one or a plurality of
blocks at a time in the drive areas L and R. At a timing to drive
blocks arranged in an interference portion 66 in one of the drive
areas L and R, the touch detecting device 1A stops driving the
blocks arranged in the other of the drive areas L and R. FIG. 13 is
a schematic of an example in which two blocks are driven at a time
in the drive area R. As illustrated in FIG. 13, when starting to
drive the interference portion 66 in the drive area R, the touch
detecting device 1A stops driving the blocks in the drive area L.
Similarly, when starting to drive the interference portion 66 in
the drive area L, the touch detecting device 1A stops driving the
blocks in the drive area R. With this control, the touch detecting
device 1A can reduce an influence of an electric field crossing a
boundary 65 between the drive areas L and R on touch detection when
driving the blocks of the interference portion 66. As a result, the
touch detecting device 1A can accurately identify the position of a
driven block and at which the value of the capacitance changes,
thereby detecting the position of a touch. Thus, the touch
detecting device 1A can provide advantages similar to those in the
first embodiment.
1-3. Third Embodiment
[0093] FIG. 14 is a schematic of a touch detecting device according
to a third embodiment. The touch detecting device 1 according to
the first embodiment and the touch detecting device 1A according to
the second embodiment require a plurality of types of signals to
drive the drive electrodes COML. The types of signals include a
first start signal to start driving of the blocks of the
independent portions 67L and 67R and a second start signal to start
and control driving of the blocks of the interference portion 66,
for example. By contrast, the touch detecting device according to
the third embodiment can drive blocks of an independent portion and
an interference portion in each drive area with one type of start
signal and one type of clock. The touch detecting device according
to the third embodiment is suitably used to provide a transfer
circuit, such as a scanner and a shift register, on the surface of
a substrate. The third embodiment is different from the first
embodiment and the second embodiment only in this respect. The
following describes only the difference, and an overlapping
explanation is omitted.
[0094] As illustrated in FIG. 14, a touch detecting device 1B
includes a first drive area 51 and a second drive area 52
corresponding to the drive areas L and R. The second drive area 52
is adjacent to the first drive area 51 in the X-direction. The
first drive area 51 and the second drive area 52 correspond to the
drive areas. The first drive area 51 is provided with a pair of
first driving units 53A serving as a driving unit to drive blocks
individually. The second drive area 52 is provided with a pair of
second driving units 53B serving as a driving unit to drive blocks
individually. The first driving units 53A and the second driving
units 53B are controlled by a control unit 11. The second driving
units 53B, for example, include a shift register controlled by a
start signal and a transfer clock supplied from the control unit
11.
[0095] In the touch detecting device 1B, an area corresponding to a
predetermined number of (three in the present embodiment) drive
electrodes COML toward the first drive area 51 side from a boundary
70 between the first drive area 51 and the second drive area 52 is
defined as a predetermined area, that is, an interference portion
71. In the touch detecting device 1B, the number of drive
electrodes COML belonging to the first drive area 51 is larger than
that of the drive electrodes COML belonging to the second drive
area 52. The drive electrodes COML belonging to the interference
portion 71 in the first drive area 51 corresponds to blocks 55 to
57. In the first drive area 51, the parts other than the
interference portion 71 serve as an independent portion 72. The
whole of the second drive area 51 serves as an independent portion
73. The number of drive electrodes COML included in the independent
portion 73 of the second drive area 52, that is, the number of
blocks included in the second drive area 52 is the same as the
number of drive electrodes COML, that is, the number of blocks
included in the independent portion 72 of the first drive area
51.
[0096] The control unit 11 sequentially applies a drive signal Vcom
from the drive electrode COML arranged farthest from the boundary
70 in the X-direction out of the drive electrodes COML belonging to
the first drive area 51 to a drive electrode COML arranged near the
boundary 70. In addition, the control unit 11 sequentially applies
a drive signal Vcom from the drive electrode COML arranged nearest
the boundary 70 in the X-direction out of the drive electrodes COML
belonging to the second drive area 52 to a drive electrode COML
arranged away from the boundary 70. The control unit 11 repeats the
processing described above. When the touch detecting device 1B
completes driving of the blocks (drive electrodes COML) arranged in
the independent portion 72 the first drive area 51 and the
independent portion 73 of the second drive area 52 and starts to
drive the blocks 55 to 57 (drive electrodes COML) arranged in the
interference portion 71 of the first drive area 51, the shift
register included in the second driving units 53B completes the
transfer. Thus, the second drive area 52 has no block (drive
electrode COML) to be driven.
[0097] After the shift register included in the second driving
units 53B completes the transfer, no drive electrode COML is
selected, whereby no drive signal Vcom (pulse) is applied to any
drive electrode COML. As a result, the shift register included in
the second driving units 53 does not operate.
[0098] In the touch detecting device 1B, only the first drive area
51 includes the interference portion 71, and the independent
portion 72 in the first drive area 51 and the independent portion
73 in the second drive area 52 have the same number of blocks. The
touch detecting device 1B simultaneously drives the blocks included
in the first drive area 51 and the second drive area 52. To drive
the blocks arranged in the interference portion 71 of the first
drive area 51, the touch detecting device 1B performs idle driving
of the second drive area 52 and waits until driving of the blocks
arranged in the interference portion 71 of the first drive area 51
is completed. After the driving of the blocks in the interference
portion 71 is completed, the touch detecting device 1B starts the
driving again from the first block in the independent portion 72 of
the first drive area 51 and the independent portion 73 of the
second drive area 52.
[0099] With this driving method, the touch detecting device 1B
requires no signal to stop driving the blocks in the second drive
area 52 when driving the interference portion 71 in the first drive
area 51. In other words, the touch detecting device 1B can drive
the blocks arranged in the independent portions 72 and 73 of the
first drive area 51 and the second drive area 52, respectively, and
the blocks in the interference portion 71 of the first drive area
51 with one type of start signal to start driving the blocks in the
first drive area 51 and the second drive area 52 and one type of
clock to control driving of the blocks. Thus, the touch detecting
device 1B can reduce the number of types of signals required to
drive the blocks compared with the touch detecting devices 1 and 1A
according to the first and the second embodiments, respectively. In
addition, the touch detecting device 1B can provide advantages
similar to those of the touch detecting devices 1 and 1A according
to the first and the second embodiments, respectively. The touch
detecting device 1B is especially used for an in-cell display
device with a touch detecting function in which an extending
direction (Y-direction) of gate lines for display is parallel to an
extending direction (Y-direction) of the drive electrodes COML.
1-4. Fourth Embodiment
[0100] FIG. 15 is a schematic of a touch detecting device according
to a fourth embodiment. A touch detecting device 1C has a dimension
of a drive electrode COML in the X-direction serving as the first
direction, that is, a dimension in which the drive electrode COML
extends larger than the entire dimension of a plurality of drive
areas (a first drive area 78 and a second drive area 79) in the
Y-direction serving as the second direction. If the touch detecting
device 1C is incorporated with a liquid-crystal display device to
be used as a display device with a touch detecting function, the
drive electrodes COML extend in the longitudinal direction of a
rectangular screen in a planar view.
[0101] The touch detecting device 1C includes the first drive area
78 and the second drive area 79 as drive areas. In the touch
detecting device 1C, a range corresponding to a predetermined
number of (two in the present embodiment) blocks of the drive
electrodes COML on the first drive area 78 side from a boundary 80
between the first drive area 78 and the second drive area 79 is
defined as an interference portion 75. In the touch detecting
device 1C, a range corresponding to a predetermined number of (two
in the present embodiment) blocks of the drive electrodes COML on
the second drive area 79 side from the boundary 80 is also defined
as the interference portion 75. Blocks of the drive electrodes COML
not included in the interference portion 75 in the first drive area
78 and the second drive area 79 serve as an independent portion
76.
[0102] The touch detecting device 1C includes a drive integrated
circuit (IC) 60 serving as an integrated circuit. The drive IC 60
includes at least a driving unit and a multiplexer that supply a
drive signal to each block. If the touch detecting device 1C is
used for a display device with a touch detecting function, the
drive electrodes COML extend in the longitudinal direction
(X-direction in FIG. 15) of the rectangular screen in a planar
view, and touch detection electrodes TDL extend in a direction
(Y-direction) orthogonal to the extending direction of the drive
electrodes COML. With this configuration, the drive IC 60 can be
arranged on an end side in the longitudinal direction of the drive
electrodes COML. This arrangement enables the drive IC 60 to have
logic, such as the driving unit and the multiplexer.
[0103] To make the extending direction of the drive electrodes COML
parallel to the short direction of the screen, it is necessary to
arrange the driving unit on both end sides of the drive electrodes
COML and on the sides of the long side of the screen like the touch
detecting device 1B illustrated in FIG. 14, for example.
[0104] The touch detecting device 1C enables the drive IC 60 to
have the logic, such as the driving unit and the multiplexer. Thus,
the driving unit need not be arranged on the sides of the long side
of the screen, thereby downsizing the touch detecting device 1C.
The touch detecting device 1C is preferably used for a display
device in which an extending direction (X-direction) of signal
lines for display is parallel to an extending direction
(X-direction) of the drive electrodes COML. The touch detecting
device 1C need not route the wiring to embed the drive IC 60 in a
COG (a chip on glass), thereby reducing the frame size and
resistance.
1-5. Fifth Embodiment
[0105] FIG. 16 and FIG. 17 are schematics of a touch detecting
device according to a fifth embodiment. The touch detecting devices
1 and 1A detect a touch using the same mutual capacitance type
detection method for the drive area R and the drive area L. The
touch detecting device 1D according to the fifth embodiment detects
a touch using different detection methods for a drive area R and a
drive area L.
[0106] A touch detecting device 1D detects a touch by using a
mutual capacitance type method for the drive area R and a
self-capacitance type method for the drive area L. To detect a
touch, a control unit 11 drives drive electrodes COML and touch
detection electrodes TDL belonging to at least one of the drive
areas (the drive area R in the present embodiment) out of the drive
areas L and R by using the mutual capacitance type method. The
control unit 11 drives, by using the self-capacitance type method,
any one or both of the drive electrodes COML and the touch
detection electrodes TDL belonging to a drive area (the drive area
L in the present embodiment) adjacent to the drive area (the drive
area R in the present embodiment) driven by the mutual capacitance
type method. To drive the touch detection electrodes TDL using the
self-capacitance type method, the control unit 11 may supply a
drive voltage via a touch detection processing unit 40.
[0107] When driving blocks of an interference portion 66 in the
drive area R driven by the mutual capacitance type method, that is,
when applying a drive signal Vcom to the drive electrodes COML of
the interference portion 66, the touch detecting device 1D (more
specifically, the control unit 11) stops driving of blocks in the
drive area L driven by the self-capacitance type method until
driving of the blocks of the interference portion 66 is completed
as illustrated in FIG. 17. Therefore, the touch detecting device 1D
can suppress an influence of an electric field crossing a boundary
65 between the drive areas L and R on touch detection in the other
area when driving the blocks of the interference portion 66
similarly to the touch detecting devices 1 and 1A. The present
embodiment drives the blocks of the drive electrodes COML belonging
to the two drive areas L and R using different methods. The same
applies to the case where the touch detecting device 1D has three
or more drive areas.
1-6. Sixth Embodiment
[0108] FIG. 18 is a block diagram of a display device with a touch
detecting function according to a sixth embodiment. The touch
detecting devices 1, 1A, 1B, 1C, and 1D are applied to a touch
detecting unit 30 of a display device 9 with a touch detecting
function of the sixth embodiment illustrated in FIG. 18. As
illustrated in FIG. 18, the display device 9 with a touch detecting
function includes a display unit 10 with a touch detecting
function, a control unit 11, a gate driver 12, a source driver 13,
a drive electrode driver 14, and a touch detection processing unit
40. While the display device 9 with a touch detecting function
shares the control unit 11 with the touch detecting devices 1, 1A,
1B, 1C, and 1D, the configuration of the present embodiment is not
limited thereto.
[0109] In the display device 9 with a touch detecting function, the
display unit 10 with a touch detecting function has a touch
detecting function. The display unit 10 with a touch detecting
function is what is called an in-cell device obtained by
integrating a liquid-crystal display unit 20 provided with
liquid-crystal display elements as display elements with the
capacitive touch detecting unit 30. The display unit 10 with a
touch detecting function may be what is called an on-cell device
obtained by mounting the capacitive touch detecting unit 30 on the
liquid-crystal display unit 20 provided with liquid-crystal display
elements as display elements. The display unit 10 with a touch
detecting function is formed of the touch detecting unit 30 serving
as a touch detecting device and the liquid-crystal display unit 20
serving as a display device.
[0110] The liquid-crystal display unit 20 sequentially scans each
horizontal line based on a scanning signal Vscan supplied from the
gate driver 12, thereby performing display, which will be described
later. The control unit 11 is a circuit that supplies control
signals to the gate driver 12, the source driver 13, the drive
electrode driver 14, and the touch detection processing unit 40
based on a video signal Vdisp supplied from the outside, thereby
controlling these components so as to operate in synchronization
with one another.
[0111] The gate driver 12 has a function to sequentially select a
horizontal line to be a target of display drive in the display unit
10 with a touch detecting function based on the control signal
supplied from the control unit 11. The source driver 13 is a
circuit that supplies a pixel signal Vpix to each pixel Pix
(sub-pixel SPix), which will be described later, in the display
unit 10 with a touch detecting function based on the control signal
supplied from the control unit 11. The source driver 13 generates a
pixel signal by time-division multiplexing the pixel signals Vpix
of a plurality of sub-pixels SPix in the liquid-crystal display
unit 20 from a video signal of a horizontal line. The drive
electrode driver 14 is a circuit that supplies a drive signal Vcom
to a drive electrode COML provided to the display unit 10 with a
touch detecting function as a drive electrode for display based on
the control signal supplied from the control unit 11.
[0112] The touch detecting unit 30 illustrated in FIG. 18
sequentially scans each detection block based on the drive signal
Vcom (touch drive signal Vcomt, which will be described later)
supplied from the drive electrode driver 14, thereby performing
touch detection. The touch detecting unit 30 outputs a touch
detection signal Vdet for each detection block from a plurality of
touch detection electrodes TDL, which will be described later, and
supplies the touch detection signal Vdet to the touch detection
processing unit 40.
[0113] The touch detection processing unit 40 is a circuit that
detects whether a touch is made on the touch detecting unit 30 (the
contact state described above) based on the control signal supplied
from the control unit 11 and the touch detection signal Vdet
supplied from the touch detecting unit 30 of the display unit 10
with a touch detecting function. If a touch is made, the touch
detection processing unit 40 derives the coordinates of the touch
in the touch detection area. The touch detection processing unit 40
includes an analog LPF 42, an A/D converter 43, a signal processing
unit 44, a coordinate extracting unit 45, and a detection timing
control unit 46.
[0114] The analog LPF 42 is a low-pass analog filter that receives
the touch detection signal Vdet supplied from the touch detecting
unit 30, removes high-frequency components (noise components)
included in the touch detection signal Vdet, and extracts and
outputs touch components. A resistance R that supplies a
direct-current (DC) potential (0 V) is arranged between each input
terminal of the analog LPF 42 and the ground. Instead of the
resistance R, a switch may be provided, for example. In this case,
the switch is turned on at predetermined time, thereby supplying
the DC potential (0 V).
[0115] The A/D converter 43 is a circuit that samples the analog
signal output from the analog LPF 42, thereby converting the analog
signal into a digital signal at a timing synchronized with the
drive signal Vcom. The signal processing unit 44 includes a digital
filter that removes high-frequency components (noise components)
higher than the frequency at which the touch drive signal Vcomt is
sampled in the output signal of the A/D converter 43, thereby
extracting touch components. The signal processing unit 44 is a
logic circuit that detects whether a touch is made on the touch
detecting unit 30 based on the output signal from the A/D converter
43. The coordinate extracting unit 45 is a logic circuit that
derives, when a touch is detected by the signal processing unit 44,
the touch panel coordinates of the touch. The detection timing
control unit 46 performs control such that the A/D converter 43,
the signal processing unit 44, and the coordinate extracting unit
45 operate in synchronization with one another.
[0116] FIGS. 19 and 20 are schematics of examples of a module on
which the display device with a touch detecting function is
mounted. To mount the display device 9 with a touch detecting
function on the module, the drive electrode driver 14 may be formed
on a TFT substrate 21, which is a glass substrate, as illustrated
in FIG. 19.
[0117] As illustrated in FIG. 19, the display device 9 with a touch
detecting function includes the display unit 10 with a touch
detecting function, the drive electrode driver 14, and a chip on
glass (COG) 19A. FIG. 19 schematically illustrates the display unit
10 with a touch detecting function including the drive electrodes
COML and the touch detection electrodes TDL formed to cross the
drive electrodes COML in a grade separated manner in a direction
perpendicular to the surface of the TFT substrate, which will be
described later. The drive electrodes COML are formed along the
short-side direction of the display unit 10 with a touch detecting
function, whereas the touch detection electrodes TDL are formed
along the long-side direction of the display unit 10 with a touch
detecting function. The output terminal of the touch detection
electrodes TDL is coupled to the touch detection processing unit 40
mounted on the outside of the module via a terminal T which is
provided on the short side of the display unit 10 with a touch
detecting function and is formed of a flexible substrate or the
like. The drive electrode driver 14 is formed on the TFT substrate
21, which is a glass substrate. The COG 19A is a chip mounted on
the TFT substrate 21 and includes circuits required for a display
operation, such as the control unit 11, the gate driver 12, and the
source driver 13 illustrated in FIG. 18. The display device 9 with
a touch detecting function may have a COG 19B integrated with the
drive electrode driver 14 as illustrated in FIG. 20.
[0118] As illustrated in FIG. 20, the display device 9 with a touch
detecting function includes the COG 19B. The COG 19B illustrated in
FIG. 20 includes the drive electrode driver 14 besides the circuits
required for the display operation described above. Integration of
the drive electrode driver 14 into the COG 19B can reduce the size
of the frame in the display device 9 with a touch detecting
function illustrated in FIG. 20. The drive electrodes COML may be
formed along the long-side direction of the display unit 10 with a
touch detecting function, and the touch detection electrodes TDL
may be formed along the short-side direction of the display unit 10
with a touch detecting function. This can reduce routing of the
wiring from each drive electrode to the COG 19B when the drive
electrode driver is embedded in the COG 19B.
[0119] The following describes an exemplary configuration of the
display unit 10 with a touch detecting function in detail.
[0120] FIG. 21 is a sectional view of a schematic sectional
structure of the display unit with a touch detecting function. FIG.
22 is a circuit diagram of a pixel array in the display unit with a
touch detecting function. The display unit 10 with a touch
detecting function includes a pixel substrate 2, a counter
substrate 3, and a liquid-crystal layer 6. The counter substrate 3
is arranged in a manner facing the surface of the pixel substrate 2
in a perpendicular direction. The liquid-crystal layer 6 is
inserted between the pixel substrate 2 and the counter substrate
3.
[0121] The pixel substrate 2 includes the TFT substrate 21, a
plurality of pixel electrodes 22, a plurality of drive electrodes
COML, and an insulation layer 24. The TFT substrate 21 serves as a
circuit board. The pixel electrodes 22 are arranged in a matrix on
the TFT substrate 21. The drive electrodes COML are formed between
the TFT substrate 21 and the pixel electrodes 22. The insulation
layer 24 provides electrical insulation between the pixel
electrodes 22 and the drive electrodes COML. The TFT substrate 21
is provided with a thin-film transistor (TFT) element Tr of each
sub-pixel SPix, and wirings, such as a pixel signal line SGL and a
scanning signal line GCL, as illustrated in FIG. 22. The pixel
signal line SGL supplies the pixel signal Vpix to each pixel
electrode 22, and the scanning signal line GCL drives each TFT
element Tr. The pixel signal line SGL extends on a plane parallel
to the surface of the TFT substrate 21 and supplies the pixel
signal used to display an image to a pixel. The liquid-crystal
display unit 20 illustrated in FIG. 22 includes a plurality of
sub-pixels SPix arranged in a matrix. The sub-pixels Spix each
include the TFT element Tr and a liquid-crystal element LC. The TFT
element Tr is formed of a thin-film transistor and specifically of
an n-channel metal oxide semiconductor (MOS) thin-film transistor
in this example. The source of the TFT element Tr is coupled to the
pixel signal line SGL, the gate is coupled to the scanning signal
line GCL, and the drain is coupled to one end of the liquid-crystal
element LC. The one end of the liquid-crystal element LC is coupled
to the drain of the TFT element Tr, and the other end is coupled to
the drive electrode COML.
[0122] The sub-pixel SPix is coupled to other sub-pixels SPix
belonging to the same row in the liquid-crystal display unit 20 by
the scanning signal line GCL. The scanning signal line GCL is
coupled to the gate driver 12 and is supplied with the scanning
signal Vscan from the gate driver 12. The sub-pixel SPix is further
coupled to other sub-pixels SPix belonging to the same column in
the liquid-crystal display unit 20 by the pixel signal line SGL.
The pixel signal line SGL is coupled to the source driver 13 and is
supplied with the pixel signal Vpix from the source driver 13. The
sub-pixel SPix is further coupled to the other sub-pixels Spix
belonging to the same column in the liquid-crystal display unit 20
by the drive electrode COML. The drive electrode COML is coupled to
the drive electrode driver 14 and is supplied with the drive signal
Vcom from the drive electrode driver 14. In other words, a
plurality of sub-pixels SPix belonging to the same column share one
drive electrode COML in this example. In the liquid-crystal display
unit 20 illustrated in FIG. 21, the drive electrode COML is
parallel to the pixel signal line SGL. The drive electrode COML may
be parallel to the scanning signal line GCL.
[0123] The gate driver 12 illustrated in FIG. 18 applies the
scanning signal Vscan to the gates of the TFT elements Tr of the
sub-pixels SPix via the scanning signal line GCL illustrated in
FIG. 22. Thus, the gate driver 12 sequentially selects a row (a
horizontal line) out of the sub-pixels SPix arranged in a matrix in
the liquid-crystal display unit 20 as a target of display drive.
The source driver 13 illustrated in FIG. 18 supplies the pixel
signal Vpix to the sub-pixels SPix constituting the horizontal line
sequentially selected by the gate driver 12 via the pixel signal
line SGL illustrated in FIG. 22. These sub-pixels SPix perform
display of the horizontal line based on the supplied pixel signal
Vpix. The drive electrode driver 14 illustrated in FIG. 18 applies
the drive signal Vcom to drive the drive electrode COML illustrated
in FIG. 21 and FIG. 22.
[0124] As described above, the gate driver 12 is driven to perform
time-division line-sequential scanning on the scanning signal line
GCL, thereby sequentially selecting a horizontal line in the
liquid-crystal display unit 20. The source driver 13 supplies the
pixel signal Vpix to the pixels Pix belonging to the horizontal
line, thereby performing display of the horizontal line in the
liquid-crystal display unit 20. To perform the display operation,
the drive electrode driver 14 applies the drive signal Vcom to the
block including the drive electrode COML corresponding to the
horizontal line.
[0125] The counter substrate 3 includes a glass substrate 31 and a
color filter 32 formed on one surface of the glass substrate 31.
The touch detection electrode TDL serving as the detection
electrode of the touch detecting unit 30 is formed on the other
surface of the glass substrate 31. A polarization plate 35A is
provided on the touch detection electrode TDL.
[0126] The color filter 32 includes color areas 32R, 32G, and 32B
colored with three colors of red (R), green (G), and blue (B),
respectively. The color filter 32 faces the COG 19 in a direction
perpendicular to the TFT substrate 21 and overlaps with the COG 19
viewed in a direction perpendicular to the surface of the TFT
substrate 21. In the color filter 32, color filters colored with
the three colors of red (R), green (G), and blue (B) are cyclically
arranged, thereby associating the sub-pixels SPix illustrated in
FIG. 22 with the color areas 32R, 32G, and 32B colored with the
three colors of red (R), green (G), and blue (B), respectively. In
addition, the color areas 32R, 32G, and 32B are associated with the
pixel Pix as a group. The color filter 32 faces the liquid-crystal
layer 6 in the direction perpendicular to the TFT substrate 21. The
color filter 32 may have another color combination as long as the
color filters are colored with different colors.
[0127] In the present embodiment, the drive electrode COML serving
as a drive electrode for display functions as a common electrode (a
common drive electrode) of the liquid-crystal display unit 20 and
as a drive electrode of the touch detecting unit 30, more
specifically, of the touch detecting devices 1, 1A, etc. In the
present embodiment, one drive electrode COML is arranged in a
manner corresponding to one pixel electrode 22 (pixel electrodes 22
constituting one row). The insulation layer 24 provides electrical
insulation between the pixel electrodes 22 and the drive electrodes
COML and between the pixel electrodes 22 and the pixel signal lines
SGL formed on the surface of the TFT substrate 21. The drive
electrodes COML face the pixel electrodes 22 in the direction
perpendicular to the surface of the TFT substrate 21. The drive
electrodes COML extend in a direction parallel to the direction in
which the scanning signal lines GCL extend. The drive electrode
driver 14 applies the drive signal Vcom in an AC rectangular
waveform to the drive electrodes COML via a contact conductive
pillar having electrical conductivity, which is not
illustrated.
[0128] The liquid-crystal layer 6 modulates light passing
therethrough depending on the state of an electric field. The
liquid-crystal layer 6 is used for, for example, a liquid-crystal
display device of lateral electric-field mode, such as fringe field
switching (FFS) and in-plane switching (IPS). An orientation film
may be provided between the liquid-crystal layer 6 and the pixel
substrate 2 and between the liquid-crystal layer 6 and the counter
substrate 3 illustrated in FIG. 21. In the present embodiment, an
orientation film is provided between the liquid-crystal layer 6 and
the pixel substrate 2 and between the liquid-crystal layer 6 and
the counter substrate 3, and an incident-side polarization plate
35B is arranged on the lower surface of the pixel substrate 2.
[0129] The drive electrode COML corresponds to a specific example
of a "drive electrode" in the present application. The touch
detection electrode TDL corresponds to a specific example of a
"detection electrode" in the present application.
[0130] The following describes an operation and advantages of the
display device 9 with a touch detecting function according to the
sixth embodiment.
[0131] FIG. 23 is a timing waveform chart of an exemplary operation
of the display device with a touch detecting function according to
the sixth embodiment. The drive electrode COML functions as a
common drive electrode of the liquid-crystal display unit 20 and as
a drive electrode of the touch detecting unit 30. Thus, the drive
signal Vcom may possibly affect both the liquid-crystal display
unit 20 and the touch detecting unit 30. To address this, the drive
signal Vcom is applied to the drive electrode COML separately in a
display period B to perform a display operation and in a touch
detection period A to perform a touch detection operation. The
drive electrode driver 14 applies the drive signal Vcom as a
display drive signal in the display period B to perform a display
operation. The drive electrode driver 14 applies the drive signal
Vcom as a touch drive signal in the touch detection period A to
perform a touch detection operation. In the description below, the
drive signal Vcom serving as the display drive signal is referred
to as a display drive signal Vcomd, whereas the drive signal Vcom
serving as the touch drive signal is referred to as a touch drive
signal Vcomt.
[0132] Based on the video signal Vdisp supplied from the outside,
the control unit 11 supplies control signals to the gate driver 12,
the source driver 13, the drive electrode driver 14, and the touch
detection processing unit 40, thereby controlling these units so as
to operate in synchronization with one another. The gate driver 12
supplies the scanning signal Vscan to the liquid-crystal display
unit 20 in the display period B, thereby sequentially selecting a
horizontal line to be a target of display drive. The source driver
13 supplies the pixel signal Vpix to each pixel Pix constituting
the horizontal line selected by the gate driver 12 in the display
period B.
[0133] In the display period B, the drive electrode driver 14
applies the display drive signal Vcomd to a drive electrode block
relating to the horizontal line. In the touch detection period A,
the drive electrode driver 14 sequentially applies the touch drive
signal Vcomt with a frequency higher than that of the display drive
signal Vcomd to a drive electrode block relating to the touch
detection operation, thereby sequentially selecting one detection
block. The display unit 10 with a touch detecting function performs
a display operation based on the signals supplied from the gate
driver 12, the source driver 13, and the drive electrode driver 14
in the display period B. The display unit 10 with a touch detecting
function performs a touch detection operation based on the signal
supplied from the drive electrode driver 14 and outputs the touch
detection signal Vdet from the touch detection electrode TDL in the
touch detection period A. The analog LPF 42 amplifies and outputs
the touch detection signal Vdet. The A/D converter 43 converts the
analog signal output from the analog LPF 42 into a digital signal
at a timing synchronized with the touch drive signal Vcomt. The
signal processing unit 44 detects whether a touch is made on the
touch detecting unit 30 based on the output signal from the A/D
converter 43. The coordinate extracting unit 45 derives, when a
touch is detected by the signal processing unit 44, the touch panel
coordinates of the touch and outputs an output signal Vout. The
control unit 11 controls the detection timing control unit 46 to
change the sampling frequency of the touch drive signal Vcomt.
[0134] The following describes a specific operation of the display
device 9 with a touch detecting function. As illustrated in FIG.
23, the liquid-crystal display unit 20 sequentially scans each
horizontal line of successive scanning signal lines GCL of the
(n-1)-th row, the n-th row, and the (n+1)-th row among the scanning
signal lines GCL based on the scanning signal Vscan supplied from
the gate driver 12, thereby performing display. Similarly, the
drive electrode driver 14 supplies the drive signal Vcom to
successive drive electrodes COML of the (m-1)-th column, the m-th
column, and the (m+1)-th column among the drive electrodes COML of
the display unit 10 with a touch detecting function based on the
control signal supplied from the control unit 11.
[0135] As described above, the display device 9 with a touch
detecting function performs the touch detection operation (touch
detection period A) and the display operation (display period B) in
a time-division manner in each display horizontal period 1H. In the
touch detection operation, the display device 9 with a touch
detecting function selects a different drive electrode COML and
applies the drive signal Vcom thereto in each display horizontal
period 1H, thereby performing scanning for touch detection. The
following describes the operation in greater detail. The gate
driver 12 applies the scanning signal Vscan to the scanning signal
line GCL of the (n-1)-th row, thereby changing a scanning signal
Vscan(n-1) from a low level to a high level. This starts a display
horizontal period 1H.
[0136] In the touch detection period A, the drive electrode driver
14 applies the drive signal Vcom to the drive electrode COML of the
(m-1)-th column, thereby changing a drive signal Vcom(m-1) from a
low level to a high level. The drive signal Vcom(m-1) is
transmitted to the touch detection electrode TDL via capacitance,
thereby changing the touch detection signal Vdet. When the drive
signal Vcom(m-1) changes from the high level to the low level, the
touch detection signal Vdet changes in the same manner. The
waveform of the touch detection signal Vdet in the touch detection
period A corresponds to the touch detection signal Vdet in the
basic principle of touch detection described above. The A/D
converter 43 carries out A/D conversion on the touch detection
signal Vdet in the touch detection period A, thereby performing
touch detection. Thus, the display device 9 with a touch detecting
function performs touch detection of one detection line.
[0137] In the display period B, the source driver 13 applies the
pixel signal Vpix to the pixel signal line SGL, thereby performing
display of a horizontal line. As illustrated in FIG. 23, the change
in the pixel signal Vpix is transmitted to the touch detection
electrode TDL via parasitic capacitance, thereby changing the touch
detection signal Vdet. In the display period B, however, the A/D
converter 43 carries out no A/D conversion, thereby making it
possible to suppress an influence of the change in the pixel signal
Vpix on touch detection. After the source driver 13 completes
supplying the pixel signal Vpix, the gate driver 12 changes the
scanning signal Vscan(n-1) of the scanning signal line GCL of the
(n-1)-th row from the high level to the low level. Thus, this
display horizontal period 1H is terminated.
[0138] Subsequently, the gate driver 12 applies the scanning signal
Vscan to the scanning signal line GCL of the n-th row, which is
different from the previous scanning signal line GCL, thereby
changing a scanning signal Vscan(n) from a low level to a high
level. This starts the next display horizontal period 1H.
[0139] In the subsequent touch detection period A, the drive
electrode driver 14 applies the drive signal Vcom to the drive
electrode COML of the m-th column, which is different from the
previous drive electrode COML. The A/D converter 43 carries out A/D
conversion on the change in the touch detection signal Vdet,
thereby performing touch detection of one detection line.
[0140] In the display period B, the source driver 13 applies the
pixel signal Vpix to the pixel signal line SGL, thereby performing
display of a horizontal line. The display device 9 with a touch
detecting function according to the present embodiment performs dot
inversion drive. Thus, the polarity of the pixel signal Vpix
applied by the source driver 13 is inverted from that in the first
display horizontal period 1H. After the display period B is
terminated, this display horizontal period 1H is terminated.
[0141] By repeating the operation described above, the display
device 9 with a touch detecting function performs a display
operation by scanning the entire display surface and performs a
touch detection operation by scanning the entire touch detection
surface.
[0142] In one display horizontal period 1H, the display device 9
with a touch detecting function performs the touch detection
operation in the touch detection period A and performs the display
operation in the display period B. Because the touch detection
operation and the display operation are performed separately in the
respective periods, the display device 9 with a touch detecting
function can perform both the display operation and the touch
detection operation in a single display horizontal period 1H. In
addition, the display device 9 with a touch detecting function can
suppress an influence of the display operation on the touch
detection. Because the display device 9 with a touch detecting
function according to the sixth embodiment is provided with the
touch detecting devices 1, 1A, etc., it can provide advantages
similar to those of the touch detecting devices 1, 1A, etc. The
display device 9 with a touch detecting function does not
necessarily perform the display operation and the touch detection
operation in one display horizontal period 1H. The display device 9
with a touch detecting function, for example, may optionally set
the touch detection period A and the display period B in one frame
period to perform display of one screen and perform the touch
detection operation and the display operation in a time-division
manner.
[0143] Modification
[0144] FIG. 24 is a schematic of an example of a module on which a
display device with a touch detecting function according to a
modification is mounted. The control system of a display device 1E
with a touch detecting function is the same as that of the display
device 9 with a touch detecting function illustrated in FIG. 18. As
illustrated in FIG. 24, the display device 1E with a touch
detecting function includes a liquid-crystal display unit 20, a
drive electrode driver 14, and a COG 19. The COG 19 includes a
source driver 13. The drive electrode driver 14 is formed on a TFT
substrate 21, which is a glass substrate. The COG 19 is a chip
mounted on the TFT substrate 21 and includes circuits required for
a display operation, such as the control unit 11 and the source
driver 13 illustrated in FIG. 18. The display device 1E with a
touch detecting function may have the COG 19 including circuits,
such as the drive electrode driver 14 and the gate driver 12.
[0145] In a display unit 10E with a touch detecting function, drive
electrodes COML and scanning signal lines GCL coupled to the gate
driver 12 are formed to cross each other in a grade separated
manner in a direction perpendicular to the surface of the TFT
substrate 21. In the display unit 10E with a touch detecting
function, pixel signal lines SGL are formed not to cross the drive
electrodes COML but to extend in a direction parallel to the drive
electrodes COML viewed in the direction perpendicular to the
surface of the TFT substrate 21.
[0146] The drive electrodes COML are formed along the long-side
direction of the display unit 10E with a touch detecting function,
whereas touch detection electrodes TDL are formed along the
short-side direction of the display unit 10E with a touch detecting
function. The output terminal of the touch detection electrodes TDL
is provided on the short side of the display unit 10E with a touch
detecting function. The output terminal is coupled to the touch
detection processing unit 40 (refer to FIG. 18) mounted on the
outside of the module via a terminal T formed of a flexible
substrate or the like.
[0147] As described above, the display device 1E with a touch
detecting function illustrated in FIG. 24 outputs the touch
detection signal Vdet from the short side of the display unit 10E
with a touch detecting function. This facilitates routing of the
wiring to couple the display device 1E with a touch detecting
function to the touch detection processing unit 40 via the terminal
T.
[0148] The display device 1E with a touch detecting function
performs display scanning in a direction parallel to a long-side
direction L of the display unit 10E with a touch detecting
function. The display device 1E with a touch detecting function
sequentially applies the drive signal Vcom to the drive electrodes
COML in a touch detection operation, thereby performing
line-sequential scanning on each detection line. In other words,
the display device 1E with a touch detecting function performs
touch detection scanning in a direction parallel to a short-side
direction S of the display unit 10E with a touch detecting
function. In the display device 1E with a touch detecting function,
the direction of the display scanning is different from that of the
touch detection scanning.
[0149] While the explanation has been made of the embodiments of
various types of devices to which the present application is
applied, the embodiments are not intended to limit the present
application, and various changes can be made in the embodiments. In
the embodiments above, for example, perform scanning by driving the
drive electrodes COML one by one. Alternatively, the embodiments
above may perform scanning by driving a predetermined number of
drive electrodes COML at a time and shifting the drive electrodes
COML one by one.
[0150] Instead of the liquid-crystal display unit 20 in various
types of modes described above, the display unit 10 with a touch
detecting function may be formed by integrating a liquid-crystal
display unit in various types of modes, such as a twisted nematic
(TN) mode, a vertical alignment (VA) mode, and an electrically
controlled birefringence (ECB) mode, with a touch detecting unit.
The display unit 10 with a touch detecting function may be
configured with lateral electric-field mode liquid crystals. In the
explanation of the embodiments above, the display device 9 with a
touch detecting function is what is called an in-cell device formed
by integrating the liquid-crystal display unit 20 with the
capacitive touch detecting unit 30. Alternatively, the display
device 9 with a touch detecting function may be formed by attaching
a capacitive touch detecting device to a liquid-crystal display
device, for example.
2. Application Examples
[0151] FIG. 25 to FIG. 31 are schematics of examples of an
electronic apparatus to which the touch detecting device according
to the present application is applied. The following describes
application examples of the touch detecting devices 1, 1A, etc.
with reference to FIG. 25 to FIG. 31. The touch detecting devices
1, 1A, etc. are applicable to electronic apparatuses of various
fields, such as television apparatuses, digital cameras, notebook
personal computers, portable electronic apparatuses including
mobile phones, and video cameras. In other words, the touch
detecting devices 1, 1A, etc. are applicable to electronic
apparatuses of various fields that display video signals received
from the outside or video signals generated inside thereof as an
image or video.
First Application Example
[0152] An electronic apparatus illustrated in FIG. 25 is a
television apparatus to which the touch detecting devices 1, 1A,
etc. are applied. The television apparatus has a video display
screen 510 including a front panel 511 and a filter glass 512, for
example. The video display screen 510 includes the touch detecting
devices 1, 1A, etc.
Second Application Example
[0153] An electronic apparatus illustrated in FIG. 26 and FIG. 27
is a digital camera to which the touch detecting devices 1, 1A,
etc. are applied. The digital camera includes a light emitting unit
521 for flash, a display unit 522, a menu switch 523, and a shutter
button 524, for example. The display unit 522 includes the touch
detecting devices 1, 1A, etc.
Third Application Example
[0154] An electronic apparatus of which the exterior appearance is
illustrated in FIG. 28 is a video camera to which the touch
detecting devices 1, 1A, etc. are applied. The video camera
includes a main body 531, a lens 532 provided to the front side
surface of the main body 531 and used for photographing a subject,
a start/stop switch 533 used in photographing, and a display unit
534, for example. The display unit 534 includes the touch detecting
devices 1, 1A, etc.
Fourth Application Example
[0155] An electronic apparatus illustrated in FIG. 29 is a notebook
personal computer to which the touch detecting devices 1, 1A, etc.
are applied. The notebook personal computer includes a main body
541, a keyboard 542 used for input of characters or the like, and a
display unit 543 that displays an image, for example. The display
unit 543 includes the touch detecting devices 1, 1A, etc.
Fifth Application Example
[0156] An electronic apparatus illustrated in FIG. 30 is a mobile
phone to which the touch detecting devices 1, 1A, etc. are applied.
The mobile phone includes an upper housing 551 and a lower housing
552 connected by a connection (a hinge) 553, for example. The
mobile phone further includes a display 554. The display 554
includes the touch detecting devices 1, 1A, etc.
Sixth Application Example
[0157] An electronic apparatus illustrated in FIG. 31 is a mobile
phone called a smartphone to which the touch detecting devices 1,
1A, etc. are applied. The mobile phone includes a touch panel 602
on the surface of a housing 601 having a substantially rectangular
thin plate shape, for example. The touch panel 602 includes the
touch detecting devices 1, 1A, etc.
3. Aspects of the Present Application
[0158] The present application includes the following aspects.
(1) A touch detecting device comprising:
[0159] a first drive area and a second drive area each including a
plurality of drive electrodes and a plurality of detection
electrodes, the plurality of drive electrodes extending in a first
direction, being arrayed in a second direction intersecting with
the first direction, and being applied with a drive signal serving
as a signal for detecting at least one of approach and contact of
an object, the plurality of detection electrodes extending in the
second direction, being arrayed in the first direction, and
outputting a detection signal serving as a signal corresponding to
a change in capacitance generated between the detection electrodes
and the drive electrodes, the first drive area and the second drive
area being arranged adjacent to each other in the second
direction;
[0160] a boundary between the first drive area and the second drive
area adjacent to each other; and
[0161] a first predetermined area included in the first drive area
and a second predetermined area included in the second drive area,
wherein
[0162] the first predetermined area and the second predetermined
area face each other with the boundary interposed therebetween,
and
[0163] application of the drive signal to the drive electrodes
arranged in the second drive area is stopped at a timing to apply
the drive signal to the drive electrodes arranged in the first
predetermined area, and application of the drive signal to the
drive electrodes arranged in the first drive area is stopped at a
timing to apply the drive signal to the second predetermined
area.
(2) The touch detecting device according to (1), wherein
application of the drive signal to all drive electrodes arranged in
the second drive area is stopped at the timing to apply the drive
signal to the drive electrodes arranged in the first predetermined
area, and application of the drive signal to all drive electrodes
arranged in the first drive area is stopped at the timing to apply
the drive signal to the second predetermined area. (3) The touch
detecting device according to (1) or (2), wherein the detection
electrodes belonging to each of the first drive area and the second
drive area adjacent to each other are arranged at a same position
on the boundary side. (4) The touch detecting device according to
any one of (1) to (3), wherein the first drive area and the second
drive area are the same in size. (5) The touch detecting device
according to any one of (1) to (4), wherein the first predetermined
area and the second predetermined area each have a dimension of
equal to or larger than one-half of the dimension of the drive
electrodes in the second direction. (6) The touch detecting device
according to any one of (1) to (5), wherein the drive signal is
simultaneously applied to at least two of the drive electrodes in
at least one drive area out of the first drive area and the second
drive area. (7) The touch detecting device according to any one of
(1) to (5), wherein touch detection in parallel in the first drive
area and the second drive area adjacent to each other is performed
in a period when no drive signal is applied to the first drive area
or the second drive area adjacent to each other. (8) The touch
detecting device according to any one of (1) to (6), wherein the
detection electrodes of the first drive area are separated from the
detection electrodes of the second drive area with the boundary
interposed therebetween, the detection electrodes of the second
drive area are separated from the detection electrodes of the first
drive area with the boundary interposed therebetween, and the first
drive area and the second drive area each include the detection
electrodes. (9) The touch detecting device according to any one of
(1) to (8), wherein
[0164] the sum of output from the detection electrodes of the first
predetermined area and output from the detection electrodes of the
second predetermined area is used as a detection signal when the
drive signal is applied to the drive electrodes belonging to the
first predetermined area and the drive electrodes belonging to the
second predetermined area, and
[0165] output from the detection electrodes of each of the first
drive area and the second drive area is used as the detection
signal when the drive signal is applied to the drive electrodes
belonging to an area other than the first predetermined area and
the second predetermined area.
(10) The touch detecting device according to any one of (1) to (8),
wherein the detection signal alone from the detection electrodes of
the first drive area or the detection electrodes of the second
drive area is detected when the drive electrodes of the first
predetermined area or the drive electrodes of the second
predetermined area are driven. (11) The touch detecting device
according to any one of (1) to (10), wherein
[0166] the first drive area and the second drive area are adjacent
to each other in the second direction,
[0167] an area corresponding to a predetermined number of the drive
electrodes toward a first drive area side from the boundary is
defined as the first predetermined area, and the number of the
drive electrodes belonging to the first drive area is larger than
that of the drive electrodes belonging to the second drive area,
and
[0168] sequentially applying the drive signal from a drive
electrode arranged farthest from the boundary in the second
direction out of the drive electrodes belonging to the first drive
area to a drive electrode arranged near the boundary, and
sequentially applying the drive signal from a drive electrode
arranged nearest the boundary or a drive electrode arranged
farthest from the boundary in the second direction out of the drive
electrodes belonging to the second drive area to a drive electrode
arranged away from the boundary are repeated.
(12) The touch detecting device according to any one of (1) to
(11), wherein the dimension of the drive electrodes in the first
direction is larger than the entire dimension of the first and
second drive areas in the second direction. (13) The touch
detecting device according to any one of (1) to (12), wherein the
drive electrodes and the detection electrodes belonging to at least
one of the first drive area and the second drive area are driven by
using a mutual capacitance type method and drives, and the drive
electrodes and the detection electrodes belonging to a drive area
not driven by the mutual capacitance type method are driven by
using a self-capacitance type method. (14) A display device with a
touch detecting function comprising the touch detecting device
according to any one of (1) to (13). (15) A display apparatus with
a touch detecting function comprising:
[0169] a touch detecting device including: [0170] a first drive
area and a second drive area each including a plurality of drive
electrodes and a plurality of detection electrodes, the plurality
of drive electrodes extending in a first direction, being arrayed
in a second direction intersecting with the first direction, and
being applied with a drive signal serving as a signal for detecting
at least one of approach and contact of an object, the plurality of
detection electrodes extending in the second direction, being
arrayed in the first direction, and outputting a detection signal
serving as a signal corresponding to a change in capacitance
generated between the detection electrodes and the drive
electrodes, the first drive area and the second drive area being
arranged adjacent to each other in the second direction; [0171] a
boundary between the first drive area and the second drive area
adjacent to each other; and [0172] a first predetermined area
included in the first drive area and a second predetermined area
included in the second drive area; and
[0173] a display device integrated with the touch detecting device,
wherein
[0174] the first predetermined area and the second predetermined
area face each other with the boundary interposed therebetween, and
a direction of display scanning performed by the display device is
different from a direction of touch detection scanning performed by
the touch detecting device.
(16) An electronic apparatus comprising the touch detecting device
according to any one of (1) to (13).
[0175] The present application can maintain excellent detection
sensitivity and excellent position detection accuracy in touch
detection and increase the detection speed.
[0176] Even when the drive signal is applied to the drive
electrodes in one of the first predetermined area belonging to the
first drive area and the second predetermined area belonging to the
second drive area and electric fields of the drive electrodes cross
the boundary, the touch detecting device according to the present
application and the display device with a touch detecting function
and the electronic apparatus including the touch detecting device
can make the electric fields less likely to affect a touch
detection operation on the other drive area because the other drive
area is stopped. Thus, the present application can maintain
excellent detection sensitivity and excellent position detection
accuracy in touch detection. The present application can apply the
drive signal to the drive electrodes arranged in the first drive
area and the second drive area at the same timing. Thus, the
present application can reduce the time required for touch
detection in the entire touch detecting device, thereby increasing
the detection speed.
[0177] The embodiments of the present application are not limited
by the foregoing descriptions. Further, the components in the above
described embodiments include components easily conceivable by
those skilled in the art and components substantially identical, in
other words, components that are within the range of equivalency.
Furthermore, the components described above can be appropriately
combined with one another. Moreover, various omissions,
alternatives and variations of the components may be possible
within the scope of the above embodiments.
[0178] It should be understood that various changes and
modifications to the presently preferred embodiments described
herein will be apparent to those skilled in the art. Such changes
and modifications can be made without departing from the spirit and
scope of the present subject matter and without diminishing its
intended advantages. It is therefore intended that such changes and
modifications be covered by the appended claims.
* * * * *