U.S. patent application number 14/882854 was filed with the patent office on 2016-07-07 for touch panel.
The applicant listed for this patent is Semiconductor Energy Laboratory Co., Ltd.. Invention is credited to Hiroyuki MIYAKE.
Application Number | 20160195983 14/882854 |
Document ID | / |
Family ID | 55914796 |
Filed Date | 2016-07-07 |
United States Patent
Application |
20160195983 |
Kind Code |
A1 |
MIYAKE; Hiroyuki |
July 7, 2016 |
TOUCH PANEL
Abstract
A touch panel with higher sensing accuracy or higher detection
sensitivity is provided. The touch panel includes a first
conductive layer, a second conductive layer, a plurality of display
elements, and a scan line. In a plan view, the first conductive
layer has an outline including a first portion that is linear and
parallel to a first direction. In the plan view, the second
conductive layer has an outline including a second portion that is
linear and parallel to the first direction. The first portion and
the second portion face each other. The display element is in a
position not overlapping with the first conductive layer nor the
second conductive layer. The scan line has a portion extending in a
second direction. An angle between the first direction and the
second direction is greater than or equal to 30.degree. and less
than or equal to 60.degree..
Inventors: |
MIYAKE; Hiroyuki; (Atsugi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Semiconductor Energy Laboratory Co., Ltd. |
Atsugi-shi |
|
JP |
|
|
Family ID: |
55914796 |
Appl. No.: |
14/882854 |
Filed: |
October 14, 2015 |
Current U.S.
Class: |
345/174 |
Current CPC
Class: |
G06F 3/0416 20130101;
G06F 3/04166 20190501; G06F 2203/04112 20130101; G06F 3/0412
20130101; G06F 3/0443 20190501; G06F 3/044 20130101; G06F 3/04164
20190501; G06F 3/0446 20190501; G06F 3/0448 20190501 |
International
Class: |
G06F 3/041 20060101
G06F003/041; G06F 3/044 20060101 G06F003/044 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 17, 2014 |
JP |
2014-212646 |
Claims
1. A touch panel comprising: a first conductive layer; a second
conductive layer; a plurality of display elements; and a scan line,
wherein the first conductive layer has an outline including a first
portion that is linear and parallel to a first direction in a plan
view, wherein the second conductive layer has an outline including
a second portion that is linear and parallel to the first direction
in the plan view, wherein the first portion and the second portion
face each other, wherein the display element is in a position not
overlapping with the first conductive layer nor the second
conductive layer, wherein the scan line has a portion extending in
a second direction, and wherein an angle between the first
direction and the second direction is greater than or equal to
30.degree. and less than or equal to 60.degree..
2. The touch panel according to claim 1, wherein the first
conductive layer and the second conductive layer each have a
lattice shape where strips parallel to the first direction and
strips parallel to a direction perpendicular to the first direction
intersect with each other with openings between them, and wherein
one of the openings overlaps with at least one of the plurality of
the display elements.
3. The touch panel according to claim 1, wherein the display
element has a polygonal shape whose two sides are parallel to the
first direction in the plan view.
4. The touch panel according to claim 1, further comprising: a
first substrate; and a second substrate, wherein the first
conductive layer, the second conductive layer, the display element,
and the scan line are between the first substrate and the second
substrate.
5. The touch panel according to claim 4, further comprising a
light-blocking layer configured to block visible light, wherein the
first substrate is provided with the display element and the scan
line, wherein the second substrate is provided with the first
conductive layer, the second conductive layer, and the
light-blocking layer, and wherein the light-blocking layer is
between the first conductive layer and the second substrate, and
between the second conductive layer and the second substrate.
6. The touch panel according to claim 4, wherein the first
conductive layer and the second conductive layer are in the same
plane.
7. The touch panel according to claim 1, wherein a distance between
the first portion and the second portion is greater than or equal
to 1 .mu.m and less than or equal to 10 mm.
8. A touch panel module comprising: the touch panel according to
claim 1, and an FPC.
9. An electronic device comprising: the touch panel according to
claim 1, and at least one of an antenna, a button, a battery, a
speaker, a microphone, and a lens.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] One embodiment of the present invention relates to an input
device. One embodiment of the present invention relates to a
display device. Further, one embodiment of the present invention
relates to an input/output device. In particular, one embodiment of
the present invention relates to a touch panel.
[0003] Note that one embodiment of the present invention is not
limited to the above technical field. Examples of the technical
field of one embodiment of the present invention include a
semiconductor device, a display device, a light-emitting device, a
power storage device, a storage device, an electronic device, a
lighting device, an input device, an input/output device, a driving
method thereof, and a manufacturing method thereof.
[0004] In this specification and the like, a semiconductor device
generally means a device that can function by utilizing
semiconductor characteristics. A semiconductor element such as a
transistor, a semiconductor circuit, an arithmetic device, and a
memory device are each an embodiment of a semiconductor device. An
imaging device, a display device, a liquid crystal display device,
a light-emitting device, an input device, an input/output device,
an electro-optical device, a power generation device (including a
thin film solar cell, an organic thin film solar cell, and the
like), and an electronic device may each include a semiconductor
device.
[0005] 2. Description of the Related Art
[0006] In recent years, a display device provided with a touch
sensor as a position-input device has been in practical use. A
display device provided with a touch sensor is called a touch
panel, a touch screen, or the like (hereinafter also referred to
simply as a touch panel). For example, a smartphone and a tablet
terminal are examples of a portable information terminal provided
with a touch panel.
[0007] Examples of the display device include, typically, a liquid
crystal display device, a light-emitting device including a
light-emitting element such as an organic electroluminescent (EL)
element or a light-emitting diode (LED), and electronic paper
performing display by an electrophoretic method or the like.
[0008] For example, in a basic structure of an organic EL element,
a layer containing a light-emitting organic compound is provided
between a pair of electrodes. By voltage application to this
element, the light-emitting organic compound can emit light. A
display device including such an organic EL element needs no
backlight which is necessary for liquid crystal display devices and
the like; therefore, thin, lightweight, high contrast, and low
power consumption display devices can be obtained. Patent Document
1, for example, discloses an example of a display device using
organic EL elements.
[0009] In a touch panel, a pressure-sensitive sensor array or a
capacitive sensor array is provided so as to overlap with a display
panel, for example; by touching a substrate of the sensor array
with a finger or an input pen (also referred to as a stylus), the
touched position is sensed.
[0010] Patent Document 2 discloses a structure of a touch panel in
which a touch sensor is provided on a display screen of an
electroluminescence display device.
REFERENCE
Patent Document
[0011] [Patent Document 1] Japanese Published Patent Application
No. 2002-324673
[0012] [Patent Document 2] Japanese Published Patent Application
No. 2000-172444
SUMMARY OF THE INVENTION
[0013] In order to obtain positional information of an object
touching a touch sensor or a touch panel more precisely, a touch
sensor with higher sensitivity is required.
[0014] An object of one embodiment of the present invention is to
provide an input device or an input/output device with higher
sensing accuracy. Another object is to provide an input device or
an input/output device with higher detection sensitivity. Another
object is to provide a novel input device or a novel input/output
device.
[0015] Note that the descriptions of these objects do not disturb
the existence of other objects. In one embodiment of the present
invention, there is no need to achieve all the objects. Other
objects can be derived from the description of the specification,
the drawings, the claims, and the like.
[0016] One embodiment of the present invention is a touch panel
including a first conductive layer, a second conductive layer, a
plurality of display elements, and a scan line. In a plan view, the
first conductive layer has an outline including a first portion
that is linear and parallel to a first direction. In the plan view,
the second conductive layer has an outline including a second
portion that is linear and parallel to the first direction. The
first portion and the second portion face each other. The display
element is in a position not overlapping with the first conductive
layer nor the second conductive layer. The scan line has a portion
extending in a second direction. An angle between the first
direction and the second direction is greater than or equal to
30.degree. and less than or equal to 60.degree..
[0017] In the above touch panel, the first conductive layer and the
second conductive layer each have a lattice shape where strips
parallel to the first direction and strips parallel to a direction
perpendicular to the first direction intersect with each other with
openings between them. The opening and the display element
preferably overlap with each other.
[0018] In the above touch panel, the display element preferably has
a polygonal shape whose two sides are parallel to the first
direction in the plan view.
[0019] The above touch panel preferably includes a first substrate
and a second substrate that sandwich the first conductive layer,
the second conductive layer, the display element, and the scan
line. It is preferable that a light-blocking layer capable of
blocking visible light be further included. In addition, it is
preferable that the first substrate be provided with the display
element and the scan line, and the second substrate be provided
with the first conductive layer, the second conductive layer, and
the light-blocking layer. Here, the light-blocking layer is
preferably between the first conductive layer and the second
substrate, and between the second conductive layer and the second
substrate.
[0020] In the above touch panel, the first conductive layer and the
second conductive layer are preferably in the same plane.
[0021] In the above touch panel, a distance between the first
portion and the second portion is preferably greater than or equal
to 1 .mu.m and less than or equal to 10 mm.
[0022] Another embodiment of the present invention is a touch panel
module including the above touch panel and an FPC.
[0023] Another embodiment of the present invention is an electronic
device including the above touch panel or the above touch panel
module, and at least one of an antenna, a button, a battery, a
speaker, a microphone, and a lens.
[0024] According to one embodiment of the present invention, an
input device or an input/output device with higher sensing accuracy
can be provided. Alternatively, an input device or an input/output
device with higher detection sensitivity can be provided.
Alternatively, a novel input device or a novel input/output device
can be provided.
[0025] Note that the descriptions of these effects do not disturb
the existence of other effects. One embodiment of the present
invention does not necessarily achieve all the effects listed
above. Other effects can be derived from the description of the
specification, the drawings, the claims, and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIGS. 1A and 1B illustrate a structure example of a touch
panel of one embodiment.
[0027] FIGS. 2A and 2B illustrate a structure example of an input
device of one embodiment.
[0028] FIG. 3 illustrates a structure example of an input device of
one embodiment.
[0029] FIGS. 4A to 4C illustrate a structure example of an input
device of one embodiment.
[0030] FIGS. 5A and 5B each illustrate a structure example of an
input device of one embodiment.
[0031] FIGS. 6A and 6B each illustrate a structure example of an
input device of one embodiment.
[0032] FIGS. 7A to 7C each illustrate a structure example of an
input device of one embodiment.
[0033] FIGS. 8A and 8B each illustrate a structure example of an
input device of one embodiment.
[0034] FIGS. 9A to 9F each illustrate a structure example of an
input device of one embodiment.
[0035] FIG. 10 illustrates a structure example of a touch panel of
one embodiment.
[0036] FIGS. 11A to 11F each illustrate a structure example of a
touch panel of one embodiment.
[0037] FIG. 12 illustrates a structure example of a touch panel of
one embodiment.
[0038] FIGS. 13A to 13D each illustrate a structure example of a
touch panel of one embodiment.
[0039] FIG. 14 illustrates a structure example of a touch panel of
one embodiment.
[0040] FIG. 15 illustrates a structure example of a touch panel of
one embodiment.
[0041] FIG. 16 illustrates a structure example of a touch panel of
one embodiment.
[0042] FIG. 17 illustrates a structure example of a touch panel of
one embodiment.
[0043] FIG. 18 illustrates a structure example of a touch panel of
one embodiment.
[0044] FIG. 19 illustrates a structure example of a touch panel of
one embodiment.
[0045] FIG. 20 illustrates a structure example of a touch panel of
one embodiment.
[0046] FIG. 21 illustrates a structure example of a touch panel of
one embodiment.
[0047] FIG. 22 illustrates a structure example of a touch panel of
one embodiment.
[0048] FIG. 23 illustrates a structure example of a touch panel of
one embodiment.
[0049] FIG. 24 illustrates a structure example of a touch panel of
one embodiment.
[0050] FIG. 25 illustrates a structure example of a touch panel of
one embodiment.
[0051] FIG. 26 illustrates a structure example of a touch panel of
one embodiment.
[0052] FIG. 27 illustrates a structure example of a touch panel of
one embodiment.
[0053] FIGS. 28A and 28B are a block diagram and a timing chart of
a touch sensor of one embodiment.
[0054] FIG. 29 is a circuit diagram of a touch sensor of one
embodiment.
[0055] FIGS. 30A and 30B illustrate a pixel provided with a touch
sensor of one embodiment.
[0056] FIGS. 31A and 31B illustrate operation of a touch sensor and
a pixel of one embodiment.
[0057] FIGS. 32A to 32H illustrate examples of electronic devices
and lighting devices of one embodiment.
[0058] FIGS. 33A to 331 illustrate examples of electronic devices
of one embodiment.
[0059] FIGS. 34A to 34E illustrate examples of electronic devices
of one embodiment.
[0060] FIGS. 35A to 35C illustrate examples of electronic devices
of one embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0061] Embodiments will be described in detail with reference to
drawings. Note that the present invention is not limited to the
description below, and it is easily understood by those skilled in
the art that various changes and modifications can be made without
departing from the spirit and scope of the present invention.
Accordingly, the present invention should not be interpreted as
being limited to the content of the embodiments below.
[0062] Note that in the structures of the invention described
below, the same portions or portions having similar functions are
denoted by the same reference numerals in different drawings, and
description of such portions is not repeated. Further, the same
hatching pattern is applied to portions having similar functions,
and the portions are not especially denoted by reference numerals
in some cases.
[0063] Note that in each drawing described in this specification,
the size, the layer thickness, or the region of each component is
exaggerated for clarity in some cases. Therefore, embodiments of
the present invention are not limited to such a scale.
[0064] Note that in this specification and the like, ordinal
numbers such as "first", "second", and the like are used in order
to avoid confusion among components and do not limit the
number.
[0065] A transistor is a kind of semiconductor elements and can
achieve amplification of current or voltage, switching operation
for controlling conduction or non-conduction, or the like. A
transistor in this specification is an insulated-gate field effect
transistor (IGFET) or a thin film transistor (TFT), for
example.
Embodiment 1
[0066] In this embodiment, a structure example of an input device
(a touch sensor) of one embodiment of the present invention, and a
structure example of an input/output device (a touch panel)
including the input device of one embodiment of the present
invention and a display device (a display panel) are described with
reference to drawings.
[0067] In the description below, a capacitive touch sensor is used
as the touch sensor of one embodiment of the present invention.
[0068] Note that in this specification and the like, a touch panel
has a function of displaying or outputting an image or the like on
or to a display surface and a function as a touch sensor capable of
detecting contact or proximity of an object such as a finger or a
stylus on or to the display surface. Therefore, the touch panel is
an embodiment of an input/output device.
[0069] In this specification and the like, a structure in which a
connector such as a flexible printed circuit (FPC) or a tape
carrier package (TCP) is attached to a substrate of a touch panel,
or a structure in which an integrated circuit (IC) is directly
mounted on a substrate by a chip on glass (COG) method is referred
to as a touch panel module or simply referred to as a touch panel
in some cases.
[0070] A capacitive touch sensor that can be used for one
embodiment of the present invention includes a pair of conductive
layers. A capacitor is formed in the pair of conductive layers. The
capacitance of the pair of conductive layers changes when an object
touches or gets close to the pair of conductive layers. Utilizing
this effect, detection can be conducted.
[0071] Examples of the capacitive touch sensor are a surface
capacitive touch sensor and a projected capacitive touch sensor.
Examples of a projected capacitive touch sensor are a
self-capacitive touch sensor and a mutual capacitive touch sensor.
The use of a mutual capacitive touch sensor is preferable because
multiple points can be detected simultaneously.
[0072] The two conductive layers each have an outline including
linear portions when viewed in a plan view. The linear portions of
the two conductive layers face and are parallel to each other. With
such a structure, the capacitance between the two conductive layers
can be increased. In a portion where the two conductive layers face
and are parallel to each other, electrical lines of force generated
when a potential difference is applied between the two conductive
layers are distributed at a uniform density. Therefore, the
difference of detection sensitivity depending on positions can be
reduced. Thus, a touch sensor with higher sensing accuracy can be
obtained.
[0073] The touch panel of one embodiment of the present invention
includes the touch sensor and a display panel (a display device)
that displays an image. The touch sensor is provided to overlap
with a display surface of the display panel.
[0074] In addition, it is preferable that a display element of the
display panel and the pair of conductive layers of a touch sensor
be provided without overlapping with each other. With such a
structure, a decrease of luminance of an image displayed on the
touch panel can be prevented, and the touch panel can have higher
visibility. Furthermore, power consumption can be reduced.
[0075] The direction of the linear portions of the pair of
conductive layers is preferably inclined at approximately
45.degree. to a horizontal direction or a perpendicular direction
of a display image displayed on the display panel. For example, an
angle between an extending direction of a scan line (also referred
to as a gate line) in the display panel and a direction of the
linear portion of the conductive layer is preferably greater than
or equal to 40.degree. and less than or equal to 50.degree..
[0076] The pair of conductive layers preferably has a lattice
(mesh) shape; such a structure can increase the conductivity of the
conductive layers. When the pair of conductive layers has a lattice
shape, it is preferable that there be portions extending in a
direction parallel to the linear portion and portions extending in
a direction perpendicular to the linear portion in the lattice
shape.
[0077] When the pair of conductive layers has a lattice shape, an
opening of the lattice and the display element preferably overlap
with each other in a plan view. Here, the display element
preferably has a polygonal outline including a side parallel to the
extending direction of the portion of the lattice in a plan view.
Such a structure will increase an aperture ratio. Alternatively,
the display element preferably has a polygonal outline including
two sides parallel to the extending direction of the linear portion
of the conductive layer or has an outline of closed line including
a linear portion in a plan view.
[0078] Specifically, the following structure can be employed, for
example.
[Structure Example]
[0079] As an example of an input/output device of one embodiment of
the present invention, structure examples of a touch panel are
described below with reference to drawings.
[Structure Example of Touch Panel]
[0080] FIG. 1A is a schematic perspective view of a touch panel 100
of one embodiment of the present invention. FIG. 1B is a schematic
perspective developed view of FIG. 1A. Note that only main
components are illustrated for simplicity. In FIG. 1B, as to some
components (a substrate 30, a substrate 72, and the like), only
their outlines are shown by broken lines.
[0081] The touch panel 100 includes an input device 10 and a
display panel 70 that overlap with each other.
[0082] In this example, the input device 10 includes the substrate
30. The substrate 30 includes an electrode 31, an electrode 32, a
plurality of wirings 41, and a plurality of wirings 42. In
addition, an FPC 50 to which the plurality of wirings 41 and the
plurality of wirings 42 are electrically connected is attached to
the substrate 30. An IC 51 is provided over the FPC 50.
[0083] As the input device 10, a capacitive touch sensor can be
used, for example. An example of using a projected capacitive touch
sensor will be described below.
[0084] As the input device 10, any of various sensors that can
sense the proximity or contact of an object such as a finger or a
stylus can be used.
[0085] Note that a specific structure of the input device 10 will
be described later.
[0086] In this example, the display panel 70 includes a substrate
71 and a substrate 72 that face each other. A display portion 81, a
driver circuit 82, a wiring 83 and the like are provided over the
substrate 71. An FPC 73 electrically connected to the wiring 83 is
provided to the substrate 71. An IC 74 is provided over the FPC
73.
[0087] The display portion 81 is a region where an image is
displayed, and includes a plurality of pixels. FIG. 1B is a
schematic view illustrating enlarged part of the display portion
81. The pixel includes at least one display element 60. The pixel
preferably includes a transistor and the display element 60. As the
display element 60, typically, a light-emitting element such as an
organic EL element, a liquid crystal element, or the like can be
used.
[0088] For the driver circuit 82, a circuit that can drive the
pixels in the display portion 81, such as a scan line driver
circuit or a signal line driver circuit, can be used. Here, an
example where a scan line driver circuit is used as the driver
circuit 82 is described.
[0089] The wiring 83 is capable of transferring a signal or an
electric power to the display portion 81 or the driver circuit 82.
The signal or the electric power is input from the outside or the
IC 74 to the wiring 83 through the FPC 73.
[0090] The display portion 81 includes a plurality of scan lines
(also referred to as gate lines) 87 that are electrically connected
to the driver circuit 82. The scan line 87 is a wiring that is
electrically connected to a gate of a transistor in the pixel. The
driver circuit 82 can sequentially supply the scan lines 87 with
signals each of which selects a plurality of pixels electrically
connected to the scan line 87.
[0091] Here, an extending direction of the scan line 87 is shown as
a direction 80 with an arrow in FIG. 1B. In the structure shown in
FIG. 1B, the direction 80 is parallel to a direction perpendicular
to a side (outline) where the driver circuit 82 of the display
portion 81 is provided. When the outline of the display portion 81
is not a rectangle or a square, the direction 80 is not
perpendicular to the outline of the display portion 81 in some
cases. The scan line 87 is not necessarily linear, and may have a
shape partly curving or twisting depending on the structure of the
pixels. At this time, the direction 80 corresponds to a direction
of a line connecting two end points of the scan line 87.
Alternatively, the direction 80 corresponds to a direction of a
line connecting two end portions of part of the scan line 87 that
overlaps with the display portion 81. Alternatively, the direction
80 can be regarded as a direction parallel to an arrangement
direction of the pixels (or subpixels) electrically connected to
one scan line 87.
[0092] FIGS. 1A and 1B show an example where the IC 74 is mounted
on the FPC 73 by a chip on film (COF) method. An IC serving as a
scan line driver circuit, a signal line driver circuit, or the like
can be used for the IC 74. Note that it is possible that the IC 74
is not provided when, for example, the display panel 70 includes
circuits serving as a scan line driver circuit and a signal line
driver circuit and when the circuits serving as a scan line driver
circuit and a signal line driver circuit are provided outside and a
signal for driving the display panel 70 is input through the FPC
73. Alternatively, the IC 74 may be directly mounted on the
substrate 71 by a COG method or the like.
[Structure Example of Input Device]
[0093] FIG. 2A is a schematic top plan view of the input device 10.
The input device 10 includes the plurality of electrodes 31, the
plurality of electrodes 32, the plurality of wirings 41, and the
plurality of wirings 42 over the substrate 30. In addition, the
substrate 30 is provided with the FPC 50 that is electrically
connected to the plurality of wirings 41 and the plurality of
wirings 42. FIG. 2A shows an example where the IC 51 is mounted on
the FPC 50. Note that the outline of the electrode 32 and that of
the electrode 31 are shown by the solid line and the broken line,
respectively, to be distinguished clearly.
[0094] In FIG. 2A, the electrode 31 is positioned to extend
horizontally. The electrode 32 is positioned to extend in a
direction intersecting with the electrode 31. As shown in FIG. 2A,
it is preferable that the electrode 31 and the electrode 32 be
perpendicular to each other.
[0095] Each of the plurality of wirings 41 is electrically
connected to one of the electrodes 31. Each of the plurality of
wirings 42 is electrically connected to one of the electrodes
32.
[0096] The IC 51 includes a circuit for driving the input device
10. The IC 51 includes, for example, a circuit for achieving a
driving method, such as a mutual capacitive method or a
self-capacitive method.
[0097] FIG. 2B is an enlarged view of a region P of FIG. 2A. The
electrode 31 and the electrode 32 overlap with and intersect with
each other at an intersection portion 90. At the intersection
portion 90, an insulator is provided between the electrodes 31 and
32 in order to prevent the electrodes 31 and 32 from being
short-circuited.
[0098] FIG. 2B shows the case where the electrode 32 locally has
the same shape as the 90.degree.-rotated electrode 31.
[0099] In a plan view, a plurality of rhombic patterns is connected
in line, horizontally or vertically, to make the electrode 31 or
the electrode 32. At this time, each rhombic pattern is preferably
a square as shown in FIG. 2B, whereby a pitch of rhombic patterns
of the electrode 31 arranged in a horizontal direction and a pitch
of rhombic patterns of the electrode 32 arranged in a vertical
direction in a view can be equal to each other. In this way,
detecting points can be arranged at equal intervals in a sensing
region of the input device 10, so that sensing accuracy can be
increased.
[0100] Part of the outline of the electrode 31 has a linear portion
21. Part of the outline of the electrode 32 has a linear portion
22. The electrodes 31 and 32 are positioned such that the linear
portions 21 and 22 face and are parallel to each other. With such a
structure, a constant gap is obtained between the electrodes 31 and
32, and the length of the facing sides of the two electrodes can be
increased. Therefore, the capacitance formed between the two
electrodes can be increased. In a portion where the two electrodes
face each other, electrical lines of force generated when a
potential difference is applied between the two electrodes are
distributed at a uniform density. Therefore, the difference of
detection sensitivity depending on positions can be reduced. Thus,
a touch sensor with higher sensing accuracy can be obtained.
[0101] As shown in FIG. 3, either the electrodes 31 or the
electrodes 32 may be provided over the substrate 30. At this time,
the other electrode may be provided on or in the display panel 70.
For example, a common electrode of a liquid crystal element may be
utilized as the electrode 31 or the electrode 32. Though the
electrode 31 is provided over the substrate 30 in FIG. 3, the
electrode 32 may be provided over the substrate 30.
[0102] FIG. 2B illustrates the direction 80 shown in FIG. 1B that
is the extending direction of the scan line 87. When the linear
portions 21 and 22 are parallel to each other, an angle between the
direction 80 and the linear portion 21 and an angle between the
direction 80 and the linear portion 22 are equal to each other.
Here, an angle between the direction 80 and the linear portion 21
or 22 is expressed as an angle .theta.. The angle .theta. is
preferably greater than or equal to 30.degree. and less than or
equal to 60.degree., preferably greater than or equal to 40.degree.
and less than or equal to 50.degree., more preferably greater than
or equal to 42.degree. and less than or equal to 48.degree., and
typically 45.degree..
[0103] A gap between the electrodes 31 and 32 is expressed as a gap
D. As the gap D is smaller, the capacitance between the two
electrodes can be increased and thus the detection sensitivity can
be increased. The size of the gap D is, for example, greater than 0
mm and less than or equal to 10 mm, preferably greater than or
equal to 1 .mu.m and less than or equal to 5 mm, more preferably
greater than or equal to 3 .mu.m and less than or equal to 1 mm, or
still more preferably greater than or equal to 5 .mu.m and less
than or equal to 500 .mu.m. Alternatively, the gap D may be the
integral multiple of a pitch of arranged subpixels or the integral
multiple of a pitch of the arranged display elements 60.
[0104] FIG. 2B shows an example where the electrodes 31 and 32 each
have a lattice shape. The integral multiple of a lattice spacing of
the electrode 31 or 32 is preferably equal to the gap D between the
electrodes 31 and 32. When the electrodes 31 and 32 have orthogonal
lattice shapes as shown in FIG. 2B, one of two directions of the
lattice is preferably parallel to the linear portion 21 or the
linear portion 22. At this time, openings in the electrodes 31 and
32 are squares inclined at the angle .theta. to the direction
80.
[0105] Although an opening in the lattice is a square in FIG. 2B,
the shape of the opening is not limited thereto and can have any of
various shapes, such as a circle, an ellipse, and a polygon with
rounded corners.
[0106] It is preferable that the electrodes 31 and 32 have been
processed to be narrow enough not to be viewed from a user. When
the electrodes 31 and 32 are processed to have a lattice (mesh)
shape as shown in FIG. 2B, high conductivity and high visibility of
the display device can be obtained. The widths of the narrowest
portions of the electrodes 31 and 32 are preferably greater than or
equal to 30 nm and less than or equal to 100 .mu.m, preferably
greater than or equal to 50 nm and less than or equal to 50 .mu.m,
or more preferably greater than or equal to 50 nm and less than or
equal to 20 .mu.m. In particular, the conductive film with a
pattern width of 10 .mu.m or less is preferable because the
conductive film with such a width is rarely recognized by a
user.
[0107] A conductive nanowire may be used for the electrodes 31 and
32. When nanowires are dispersed at an appropriate density such
that adjacent nanowires are in contact with each other, a
two-dimensional network is formed and works as a conductive film
with an extremely high light-transmitting property. For example, a
nanowire with an average diameter of greater than or equal to 1 nm
and less than or equal to 100 nm, preferably greater than or equal
to 5 nm and less than or equal to 50 nm, or more preferably greater
than or equal to 5 nm and less than or equal to 25 nm can be used.
As the nanowire, a carbon nanotube or a metal nanowire such as an
Ag nanowire, a Cu nanowire, and an Al nanowire can be used. For
example, in the case of using an Ag nanowire, light transmittance
of 89% or more and a sheet resistance of 40 ohm/square or more and
100 ohm/square or less can be achieved.
[0108] As shown in FIG. 4A, the electrode 32 may be composed of a
plurality of electrodes 33 and a bridge electrode 34. For easy
understanding of a relative position of the electrode 33 and the
bridge electrode 34, only the bridge electrode 34 is shown by a
broken line in FIG. 4B while only the bridge electrode 34 is shown
by a solid line in FIG. 4C. There is no particular limitation on
the formation order of the bridge electrode 34 and the electrodes
31 and 33, and either the bridge electrode 34 or the electrodes 31
and 33 may be provided on the substrate 30 side.
[0109] The island-shaped electrodes 33 are arranged in a vertical
direction, and the two adjacent electrodes 33 are electrically
connected to each other by the bridge electrode 34. With such a
structure, the electrodes 33 and 31 can be formed at a time by
processing the same conductive film. Therefore, variations in their
film thicknesses or line widths can be reduced, and variations in
the resistance of each electrode depending on positions can be
suppressed. In addition, with such a structure, the electrodes 33
and 31 can be arranged in the same plane. Thus, the electrodes 31
and 33 are not misaligned in a height direction, whereby electrical
lines of force generated therebetween can be uniformly distributed
and the detection sensitivity of the input device 10 can be
increased.
[0110] Although the electrode 32 has the bridge electrode 34 here,
the electrode 31 may have such a structure. At that time, when the
influence of the contact resistance become noticeable because of
provision of the bridge electrode 34, a structure with the bridge
electrodes 34 is preferably employed for the electrode 31 or 32,
whichever is shorter, so that the number of bridge electrodes 34 in
the one electrode can be reduced.
[0111] FIG. 5A is an enlarged view of a region Q of FIG. 2A. The
region Q is a region including a corner portion of the sensing
region of the input device 10.
[0112] As shown in FIG. 5A, the electrodes 31 and 32 preferably
have shapes in each of which an end portion is apparently cut
parallel to or perpendicular to the direction 80 at the corner
portion of the sensing region. The outlines of the electrodes 31
and 32 preferably have linear portions parallel to or perpendicular
to the direction 80. With such a structure, the bezel of the touch
panel 100 where the input device 10 and the display panel 70 are
combined can be narrowed.
[0113] FIG. 5B shows the case where the gap D is wider than that of
FIG. 5A. When the gap between the electrodes 31 and 32 is wide like
this, the intersection portion 90 preferably has a lattice shape.
FIG. 5B shows that the electrode 32 has the bridge electrode 34
with the lattice shape. When the bridge electrode 34 is not used as
shown in FIG. 2B, each of the electrodes 31 and 32 may have a
lattice shape at the intersection portion 90.
[0114] The case where the electrodes 31 and 32 have the lattice
shapes is shown above, but the shapes of the electrodes 31 and 32
are not limited thereto and can have any of other various shapes as
long as they have facing linear portions.
[0115] In addition, as shown in FIGS. 6A and 6B, a dummy electrode
35 that is electrically isolated from the electrodes 31 and 32 may
be positioned between the electrodes 31 and the electrode 32. With
such a structure, a region where neither the electrode 31 nor the
electrode 32 exists is less likely to be recognized by a user.
[0116] FIG. 7A shows the case where the insides of the rhombic
patterns of the electrodes 31 and 33 of FIG. 4A are hollow and only
the outlines thereof are formed. FIG. 7B shows the case where only
the linear portions of the lattices in a certain direction remain
in the electrodes 31 and 33. FIG. 7C shows the case where the
electrodes 31 and 33 include zigzag patterns. In that case, the
linear portions of the zigzag patterns are preferably parallel to
the linear portions of the outline of the electrode 31 or 33. In
addition, the zigzag patterns are preferably positioned to extend
in the extending direction of the electrode 31 or 32 as shown in
FIG. 7C, whereby electric resistance in the direction can be
reduced.
[0117] Although the electrode 32 has the bridge electrode 34 in
FIGS. 7A to 7C, the bridge electrode 34 is not necessarily provided
as shown in FIG. 2B.
[0118] Although FIG. 2A and the like show the case where a
plurality of rhombuses are connected in line is shown as a top
surface shape of the electrode 31 or 32, the shapes of the
electrodes 31 and 32 are not limited thereto and can have any of
various top surface shapes, such as a stripe (rectangle) shape, a
stripe shape with curves, or a zigzag shape. In addition, though
the electrodes 31 and 32 are positioned to be perpendicular to each
other above, they are not necessarily positioned to be
perpendicular to each other and an angle between the two electrodes
may be less than 90.degree..
[0119] FIG. 8A shows an example where electrodes 36 and 37 with
zigzag top surface shapes are used. For clarification, in FIG. 8A
and the like, the electrode 36 and the electrode 37 are shown by
the broken line and the solid line, respectively. Here, as shown in
FIG. 8A, it is preferable that the electrodes be positioned such
that the center portion of a linear portion in the zigzag shape of
one electrode not overlap with that of a linear portion in the
zigzag shape of the other electrode, and the center portions be
relatively off from each other. With such a preferable structure,
the portions of the electrodes 36 and 37 that face and are parallel
to each other can be close to each other, and the capacitance
formed between the electrodes and the detection sensitivity can be
increased. Alternatively, when part of the linear portions of the
zigzag shapes projects in the top surface shapes of the electrodes
36 and 37 as shown in FIG. 8B, the capacitance between the
electrodes can be increased because the length of the facing sides
can be increased even if the center portions of the linear portions
overlap with each other.
[0120] FIG. 9A is an enlarged view of a region surrounded by a
chain line in FIG. 8A, and FIG. 9D is an enlarged view of a region
surrounded by a chain line in FIG. 8B. Each drawing shows the
electrode 36, the electrode 37, and an intersection portion 38
where these electrodes intersect with each other. Here, the linear
portions of the electrodes 36 and 37 of FIGS. 9A and 9D may have
meander shapes with angled corners as shown in FIGS. 9B and 9E.
Alternatively, the linear portions of the electrodes 36 and 37 may
have continuously-curved meander shapes as shown in FIGS. 9C and
9F.
[0121] That is the description of the structure examples of the
input device.
[Structure Example of Pixel]
[0122] Structure examples of a pixel in the display panel 70 in the
touch panel 100 of one embodiment of the present invention are
described below.
[0123] As described above, there is a plurality of pixels in the
display portion of the display panel 70. A pixel includes one or
more display elements 60. If the display panel 70 displays a full
color image, a structure where the display elements 60 for
exhibiting three colors of red (R), green (G), and blue (B) are
provided in one pixel is preferable, for example. A structure where
the display elements 60 for exhibiting yellow (Y) and white (W) are
provided in addition to the display elements for the above three
colors is also preferable because power consumption can be reduced.
Here, a structure including one display element 60 and a pixel
circuit corresponding thereto is referred to as a subpixel in some
cases. When a pixel includes the three display elements 60, the
pixel can have a structure with three subpixels.
[0124] When the input device 10 overlaps with the display panel 70,
it is preferable that the electrodes 31 and 32 in the input device
10 be positioned between the display elements 60. Then, the
electrodes 31 and 32 do not block light from the display elements
60, whereby it is possible to almost completely avoid, or greatly
reduce luminance decrease in the display panel 70 provided with the
input device 10. Therefore, a touch panel with high visibility and
low power consumption can be achieved. In addition, since the
electrodes 31 and 32 do not overlap with the display element 60, it
is not necessary to use a light-transmitting conductive material,
which has relatively high resistance, for the electrodes 31 and 32.
Therefore, it is possible to use a metal or an alloy material with
low resistance for the electrodes 31 and 32, and thus it is
possible to make the electrodes 31 and 32 extremely thin so as not
to be recognized by bare eyes. Thus, the electrodes 31 and 32 are
less likely to be recognized by light reflection or the like,
whereby a touch panel with higher visibility can be obtained.
[0125] FIG. 10 is an enlarged view of the display portion 81 and
the input device 10 that overlap with each other when viewed from
the display surface side of the touch panel 100 of FIG. 1A. Here, a
pixel 40 in the display panel 70 includes four display elements 60
exhibiting different colors (a display element 60R, a display
element 60G, a display element 60B, and a display element 60Y).
Hereinafter, description is made for the display element 60 when
matters common to the four kinds of display elements are
described.
[0126] FIG. 10 shows a positional relationship between the
electrode 31 and the display elements 60. Note that the electrode
31 is illustrated here, but the same applies to the electrode 32
(or the electrode 33 and the bridge electrode 34). In FIG. 10, for
describing a direction of scan lines 87 in the display panel 70,
three scan lines (a scan line 87a, a scan line 87b, and a scan line
87c) are shown by broken lines, and the direction 80 that is the
extending direction of the scan lines is also shown.
[0127] In a structure in FIG. 10, an angle between a linear portion
of the lattice of the electrode 31 and the scan line 87 is
45.degree.. The display elements 60 are arranged along the linear
portion of the electrode 31. Here, a plurality of display elements
60 arranged obliquely in FIG. 10 are two kinds of display elements
60 exhibiting different two colors that are alternately arranged.
One pixel 40 includes the four adjacent display elements 60
(display elements 60R, 60G, 60B, and 60Y). Here, the display
elements 60R, 60G, 60B, and 60Y are display elements exhibiting
red, green, blue, and yellow, respectively.
[0128] An outline of one display element 60 preferably has a
portion parallel to the linear portion of the lattice of the
electrode 31. With such a form, a gap between the two display
elements 60 can be reduced when the display elements 60 are
arranged, whereby an aperture ratio can be increased. Although the
outline of the display element 60 is a quadrangle with rounded
corners, the outline shape is not limited thereto, and may be a
square, a rectangle, a polygon, an ellipse, a circle, a polygon
with rounded corners, or the like.
[0129] The scan line 87a in FIG. 10 corresponds to a scan line for
driving a subpixel including the display element 60R, for example.
The scan line 87b corresponds to a scan line for driving a subpixel
including the display element 60G and a subpixel including the
display element 60Y The scan line 87c corresponds to a scan line
for driving a subpixel including the display element 60B. Each scan
line is electrically connected to a gate of a transistor in each
subpixel. That is, in the structure shown in FIG. 10, one pixel can
be driven by the three scan lines 87.
[0130] In FIG. 10, a structure where one pixel 40 (that is, four
display elements 60) is included in an opening of the electrode 31
is shown; however, the structure of the electrode 31 is not limited
thereto, and may be any of various structures as long as the
electrode 31 is configured to be positioned between the adjacent
display elements 60.
[0131] FIG. 11A shows the case where an opening of the lattice of
the electrode 31 includes one display element 60. FIG. 11B shows
the case where the electrode 31 has a stripe shape. FIG. 11C shows
the case where an opening of the lattice of the electrode 31
includes a plurality of pixels 40. FIG. 11D shows the case where a
pitch of the lattice in one direction is different from a pitch of
the lattice in another direction perpendicular to the one
direction. FIGS. 11E and 11F show the case where the electrode 31
has a zigzag shape like that shown in FIG. 7C.
[0132] FIG. 10 and FIGS. 11A to 11F show examples where one pixel
40 includes the display elements 60 of four colors, but the number
of colors of display elements in a pixel is not limited thereto,
and the display elements of three colors, five colors, or more may
be provided.
[0133] FIG. 12 shows the case where one pixel 40 includes the
display elements 60 of three colors. For simplifying the
description, a pixel 40a, a pixel 40b, and a pixel 40c are shown
separately from the others and three display elements 60 in each of
the pixels 40a, 40b, and 40c are shown by the same hatching pattern
in FIG. 12.
[0134] As to the pixels 40a and 40b that are aligned in a vertical
direction, arrangement of the three display elements 60 in the
pixel 40a is the same as that in the pixel 40b. As to the pixels
40a and 40c that are aligned in a horizontal direction, the
arrangement of the three display elements 60 in the pixel 40a is in
a vertically inverse relation to that in the pixel 40c.
[0135] In FIG. 12, the display elements 60 of the same color are
aligned in a vertical direction of the drawing. Such a structure is
preferable because the structure will make it easier to separately
form color filters or light-emitting elements in accordance with
colors of the display elements.
[0136] FIG. 13A shows the case where one pixel includes the display
elements 60 of three colors. The outline of the display element 60
has a linear portion along a direction of the lattice of the
electrode 31, and has a rectangular shape with rounded corners. The
display elements of the same color are aligned in the direction of
the linear portion of the lattice of the electrode 31, which
constitutes stripe arrangement. In each of FIGS. 13B, 13C, and 13D,
the electrode 31 has a different shape from that in FIG. 13A.
[0137] Note that marks such as R, G, B, and Y are given to some
display elements 60 in FIG. 10 to FIG. 13D to facilitate
description; however, the arrangement method is just an example,
and does not limit an arrangement method of the display elements
60. R, G, B, and Y can be replaced with one another. In addition, W
that corresponds to a display element of white may be provided in
replacement of R, G, B, or Y.
[0138] The above is the description of the structure example of the
pixel.
[Cross-Sectional Structure Example]
[0139] An example of a cross-sectional structure of the touch panel
100 is described below with reference to drawings.
[Cross-Sectional Structure Example 1]
[0140] FIG. 14 is a schematic cross-sectional view of the touch
panel 100. FIG. 14 illustrates cross sections of a region including
an FPC 73, a region including the driver circuit 82, a region
including the display portion 81, and a region including the FPC 50
in FIG. 1A.
[0141] The substrate 71 and the substrate 72 are attached to each
other with an adhesive layer 151. The substrate 72 and the
substrate 30 are attached to each other with an adhesive layer 152.
Here, a structure including the substrate 71, the substrate 72, and
components provided therebetween corresponds to the display panel
70. A structure including the substrate 30 and components provided
on the substrate 30 corresponds to the input device 10.
<Display Panel 70>
[0142] A transistor 201, a transistor 202, a transistor 203, the
display element 60, a capacitor 205, a connection portion 206, a
wiring 207, and the like are provided between the substrates 71 and
72.
[0143] An insulating layer 211, an insulating layer 212, an
insulating layer 213, an insulating layer 214, an insulating layer
215, a spacer 216, and the like are provided over the substrate 71.
Part of the insulating layer 211 functions as a gate insulating
layer of each transistor, and another portion thereof functions as
a dielectric of the capacitor 205. The insulating layer 212, the
insulating layer 213, and the insulating layer 214 are provided to
cover each transistor, the capacitor 205, and the like. The
insulating layer 214 functions as a planarization layer. Note that
an example where the three insulating layers, the insulating layers
212, 213, and 214, are provided to cover the transistors and the
like is described here; however, the present invention is not
limited to this example, and four or more insulating layers, a
single insulating layer, or two insulating layers may be provided.
The insulating layer 214 functioning as a planarization layer is
not necessarily provided when not needed.
[0144] The display element 60 is provided over the insulating layer
214. Here, an example is shown where a top-emission type
light-emitting element (organic EL element) is used as the display
element 60. The display element 60 emits light toward a second
electrode 223 side. When the transistors 202 and 203, the capacitor
205, the wiring or the like are provided to overlap with the
light-emitting region of the display element 60, the aperture ratio
of the display portion 81 can be increased.
[0145] The display element 60 includes an EL layer 222 between a
first electrode 221 and the second electrode 223. An optical
adjustment layer 224 is provided between the first electrode 221
and the EL layer 222. The insulating layer 215 is provided to cover
end portions of the first electrode 221 and the optical adjustment
layer 224.
[0146] FIG. 14 illustrates a cross section of one pixel as an
example of the display portion 81. An example where the pixel
includes the transistor 202 for current control, the transistor 203
for switching control, and the capacitor 205 is described here. One
of a source and a drain of the transistor 202 and one electrode of
the capacitor 205 are electrically connected to the first electrode
221 through an opening provided in the insulating layers 212, 213,
and 214.
[0147] FIG. 14 illustrates an example of the driver circuit 82 in
which the transistor 201 is provided.
[0148] Each of the transistors 201, 202 and 203 has a conductive
layer 241 functioning as a gate electrode, a semiconductor layer
242, a pair of conductive layers 243, and an insulating layer 211
functioning as a gate insulator. One of the conductive layers 243
functions as a source electrode while the other of the conductive
layers 243 functions as a drain electrode.
[0149] In the example illustrated in FIG. 14, the transistors 201
and 202 each have a structure in which a semiconductor layer where
a channel is formed is provided between two gate electrodes
(conductive layers 241 and 244). Such transistors can have higher
field-effect mobility and thus have higher on-state current than
other transistors. Consequently, a circuit capable of high-speed
operation can be obtained. Furthermore, the area occupied by a
circuit can be reduced. The use of the transistor having high
on-state current can reduce signal delay in wirings and can reduce
display luminance variation even in a display panel in which the
number of wirings is increased because of increase in size or
resolution.
[0150] Note that the transistors provided in the driver circuit 82
and the display portion 81 may have the same structure or different
structures.
[0151] A material through which impurities such as water or
hydrogen do not easily diffuse is preferably used for at least one
of the insulating layers 212 and 213 which cover the transistors.
That is, the insulating layer 212 or the insulating layer 213 can
function as a barrier film. Such a structure can effectively
suppress diffusion of the impurities into the transistors from the
outside, and a highly reliable touch panel can be achieved.
[0152] The spacer 216 is provided over the insulating layer 215 and
has a function of adjusting the distance between the substrate 71
and the substrate 72. In the example illustrated in FIG. 14, there
is a gap between the spacer 216 and a light-blocking layer 232,
which may however be in contact with each other. Although the
spacer 216 is provided on the substrate 71 side in the structure
described here, the spacer 216 may be provided on the substrate 72
side (e.g., in a position closer to the substrate 71 than that of
the light-blocking layer 232). Alternatively, a particulate spacer
may be used instead of the spacer 216. Although a material such as
silica can be used for the particulate spacer, an elastic material
such as an organic resin or rubber is preferably used. In some
cases, the particulate spacer may be vertically crushed.
[0153] A coloring layer 231, the light-blocking layer 232, and the
like are provided on the substrate 71 side of the substrate 72. The
light-blocking layer 232 has an opening, and the opening overlaps
with the display region of the display element 60. The coloring
layer 231 overlaps with the display element 60.
[0154] As examples of a material that can be used for the
light-blocking layer 232, carbon black, a metal oxide, and a
composite oxide containing a solid solution of a plurality of metal
oxides can be given. Stacked films containing the material of the
coloring layer 231 can also be used for the light-blocking layer
232. For example, a material containing an acrylic resin can be
used for the coloring layer 231, and a stacked-layer structure of a
film containing a material of a coloring layer which transmits
light of a certain color and a film containing a material of a
coloring layer which transmits light of another color can be
employed. It is preferable that the coloring layer 231 and the
light-blocking layer 232 be formed using the same material because
the same manufacturing apparatus can be used and the process can be
simplified.
[0155] As examples of a material that can be used for the coloring
layer 231, a metal material, a resin material, and a resin material
containing a pigment or dye can be given.
[0156] An insulating layer which functions as an overcoat may be
provided to cover the coloring layer 231 and the light-blocking
layer 232.
[0157] The connection portion 206 is provided in a region near an
end portion of the substrate 71. The connection portion 206 is
electrically connected to the FPC 73 through a connection layer
209. In the example of the structure illustrated in FIG. 14, the
connection portion 206 is formed by stacking part of the wiring 207
which is electrically connected to the driver circuit 82 and a
conductive layer which is formed by processing a conductive film
used for forming the first electrode 221. When the connection
portion 206 is formed by stacking two or more conductive layers as
described above, electric resistance can be reduced and mechanical
strength of the connection portion 206 can be increased.
[0158] Furthermore, FIG. 14 illustrates a cross-sectional structure
of an intersection portion 86 where a wiring formed by processing a
conductive film used for forming the gate electrode of the
transistor and a wiring formed by processing a conductive film used
for forming a source electrode and a drain electrode of the
transistor intersect with each other.
[0159] Here, the scan line 87 formed by processing a conductive
film used for forming the gate electrode of the transistor is
provided at the intersection portion 86. Note that the scan line 87
may be a wiring formed by processing a conductive film used for
forming the source electrode and the drain electrode of a
transistor or another conductive film.
<Input Device 10>
[0160] The electrode 31 and the electrode 32 are provided on the
substrate 72 side of the substrate 30. An example where the
electrode 31 includes the electrode 33 and the bridge electrode 34
is described here. As illustrated in the intersection portion 86 in
FIG. 14, the electrode 32 and the electrode 33 are formed in the
same plane. The bridge electrode 34 is provided over an insulating
layer 161 which covers the electrode 32 and the electrode 33. The
bridge electrode 34 electrically connects two electrodes 33,
between which the electrode 32 is provided, through openings formed
in the insulating layer 161.
[0161] In the structure of FIG. 14, the electrode 33 does not
overlap with the display element 60. That is, the electrode 33 is
provided such that an opening of the electrode 33 and the display
element 60 overlap with each other. Here, it is preferable that the
electrode 33 not overlap with the coloring layer 231. The electrode
33 preferably overlaps with the light-blocking layer 232. Note that
an example of the electrode 33 is shown here, but it is preferable
that the electrodes 31 and 32 and the bridge electrode 34 also not
overlap with the display element 60 or the like.
[0162] A connection portion 106 is provided in a region near an end
portion of the substrate 30. The connection portion 106 is
electrically connected to the FPC 50 through a connection layer
109. In the example of the structure illustrated in FIG. 14, the
connection portion 106 is formed by stacking part of the wiring 42
and a conductive layer which is formed by processing a conductive
film used for forming the bridge electrode 34.
[0163] As the connection layer 109 or the connection layer 209, an
anisotropic conductive film (ACF), an anisotropic conductive paste
(ACP), or the like can be used.
[0164] The substrate 30 here can be used also as a substrate with
which an object to be sensed, such as a finger or a stylus, is to
be in contact. In that case, a protective layer (such as a ceramic
coat) is preferably provided over the substrate 30. The protective
layer can be formed using an inorganic insulating material such as
silicon oxide, aluminum oxide, yttrium oxide, or yttria-stabilized
zirconia (YSZ). Alternatively, tempered glass may be used for the
substrate 30. The tempered glass which can be used here is one that
has been subjected to physical or chemical treatment by an ion
exchange method, a thermal tempering method, or the like and has a
surface to which compressive stress has been added. In the case
where the touch sensor is provided on one side of the tempered
glass and the opposite side of the tempered glass is provided on,
for example, the outermost surface of an electronic device for use
as a touch surface, the thickness of the whole device can be
decreased.
<Components>
[0165] The above-mentioned components are described below.
[0166] A substrate having a flat surface can be used as the
substrate included in the touch panel. The substrate on the side
from which light from the display element is extracted is formed
using a material that transmits the light. For example, a material
such as glass, quartz, ceramics, sapphire, or an organic resin can
be used.
[0167] The weight and thickness of the touch panel can be decreased
by using a thin substrate. A flexible touch panel can be obtained
by using a substrate that is thin enough to have flexibility.
[0168] As the glass, for example, non-alkali glass, barium
borosilicate glass, aluminoborosilicate glass, or the like can be
used.
[0169] Examples of a material that has flexibility and transmits
visible light include flexible glass, polyester resins such as
polyethylene terephthalate (PET) and polyethylene naphthalate
(PEN), a polyacrylonitrile resin, a polyimide resin, a polymethyl
methacrylate resin, a polycarbonate (PC) resin, a polyethersulfone
(PES) resin, a polyamide resin, a cycloolefin resin, a polystyrene
resin, a polyamide imide resin, a polyvinyl chloride resin, and a
polytetrafluoroethylene (PTFE). In particular, a material whose
thermal expansion coefficient is low is preferable, and for
example, a polyamide imide resin, a polyimide resin, or PET can be
suitably used. A substrate in which a glass fiber is impregnated
with an organic resin or a substrate whose thermal expansion
coefficient is reduced by mixing an organic resin with an inorganic
filler can also be used. A substrate using such a material is
lightweight, and accordingly a touch panel using this substrate can
also be lightweight.
[0170] Since it is not necessary for the substrate through which
light emission is not extracted to have a light-transmitting
property, a metal substrate, a ceramic substrate, a semiconductor
substrate, or the like can be used as well as the above-described
substrates. A metal substrate, which has high thermal conductivity,
is preferable because they can easily conduct heat to the whole
substrate and accordingly can prevent a local temperature rise in
the touch panel. To obtain flexibility and bendability, the
thickness of a metal substrate is preferably greater than or equal
to 10 .mu.m and less than or equal to 200 .mu.m, more preferably
greater than or equal to 20 .mu.m and less than or equal to 50
.mu.m.
[0171] Although there is no particular limitation on a material of
a metal substrate, it is favorable to use, for example, a metal
such as aluminum, copper, and nickel, an aluminum alloy, or an
alloy such as stainless steel.
[0172] It is preferable to use a substrate subjected to insulation
treatment, e.g., a metal substrate whose surface is oxidized or
provided with an insulating film. An insulating film may be formed
by, for example, a coating method such as a spin-coating method and
a dipping method, an electrodeposition method, an evaporation
method, or a sputtering method. An oxide film may be formed over
the substrate surface by a known method such as an anodic oxidation
method, exposing to or heating in an oxygen atmosphere, or the
like.
[0173] A hard coat layer (e.g., a silicon nitride layer) by which a
touch panel surface is protected from damage, a layer (e.g., an
aramid resin layer) that can disperse pressure, or the like may be
stacked over the flexible substrate. Furthermore, to suppress a
decrease in lifetime of the display element due to water and the
like, an insulating film with low water permeability may be
provided to the flexible substrate. For example, a film containing
nitrogen and silicon (e.g., a silicon nitride film, a silicon
oxynitride film), or a film containing nitrogen and aluminum (e.g.,
an aluminum nitride film) may be provided.
[0174] The substrate may be formed by stacking a plurality of
layers. When a glass layer is used, a barrier property against
water and oxygen can be improved and thus a highly reliable touch
panel can be provided.
[0175] A substrate in which a glass layer, an adhesive layer, and
an organic resin layer are stacked from the side closer to the
display element can be used, for example. The thickness of the
glass layer is greater than or equal to 20 .mu.m and less than or
equal to 200 .mu.m, preferably greater than or equal to 25 .mu.m
and less than or equal to 100 .mu.m. With such a thickness, the
glass layer can have both a high barrier property against water and
oxygen and a high flexibility. The thickness of the organic resin
layer is greater than or equal to 10 .mu.m and less than or equal
to 200 .mu.m, preferably greater than or equal to 20 .mu.m and less
than or equal to 50 .mu.m. Providing such an organic resin layer
outside the glass layer, occurrence of a crack or a break in the
glass layer can be suppressed and mechanical strength can be
improved. With the substrate that includes such a composite
material of a glass material and an organic resin, a highly
reliable flexible touch panel can be provided.
[0176] The transistor includes a conductive layer functioning as
the gate electrode, the semiconductor layer, a conductive layer
functioning as the source electrode, a conductive layer functioning
as the drain electrode, and an insulating layer functioning as the
gate insulating layer.
[0177] Note that there is no particular limitation on the structure
of the transistor included in the touch panel of one embodiment of
the present invention. For example, a forward staggered transistor
or an inverted staggered transistor may be used. A top-gate
transistor or a bottom-gate transistor may be used. There is no
particular limitation on a semiconductor material that is used for
the transistors, and for example, an oxide semiconductor, silicon,
germanium, or an organic semiconductor can be used.
[0178] There is no particular limitation on the crystallinity of a
semiconductor material used for the transistors, and an amorphous
semiconductor or a semiconductor having crystallinity (a
microcrystalline semiconductor, a polycrystalline semiconductor, a
single-crystal semiconductor, or a semiconductor partly including
crystal regions) may be used. It is preferable that a semiconductor
having crystallinity be used, in which case deterioration of the
transistor characteristics can be suppressed.
[0179] As a semiconductor material for the semiconductor layer of
the transistor, an element of Group 14, a compound semiconductor,
or an oxide semiconductor can be used, for example. Typically, a
semiconductor containing silicon, a semiconductor containing
gallium arsenide, an oxide semiconductor containing indium, or the
like can be used.
[0180] An oxide semiconductor is preferably used as a semiconductor
in which the channel of the transistor is formed. In particular, an
oxide semiconductor having a wider band gap than silicon is
preferably used. A semiconductor material having a wider band gap
and a lower carrier density than silicon is preferably used because
off-state leakage current of the transistor can be reduced.
[0181] For example, at least indium (In) or zinc (Zn) is preferably
included as the oxide semiconductor. More preferably, an
In-M-Zn-based oxide (M is a metal such as Al, Ti, Ga, Ge, Y, Zr,
Sn, La, Ce, or Hf) is included.
[0182] As the semiconductor layer, it is particularly preferable to
use an oxide semiconductor film including a plurality of crystal
parts whose c-axes are aligned substantially perpendicular to a
surface on which the semiconductor layer is formed or the top
surface of the semiconductor layer and in which a grain boundary is
not observed between adjacent crystal parts.
[0183] There is no grain boundary in such an oxide semiconductor;
therefore, generation of a crack in an oxide semiconductor film
which is caused by stress when a display panel is bent is
prevented. Therefore, such an oxide semiconductor can be preferably
used for a flexible touch panel which is used in a bent state, or
the like.
[0184] Moreover, the use of such an oxide semiconductor with
crystallinity for the semiconductor layer makes it possible to
provide a highly reliable transistor in which a change in the
electrical characteristics is suppressed.
[0185] A transistor with an oxide semiconductor whose band gap is
larger than the band gap of silicon can hold charges stored in a
capacitor that is series-connected to the transistor for a long
time, owing to the low off-state current of the transistor. When
such a transistor is used for a pixel, operation of a driver
circuit can be stopped while a gray scale of an image displayed in
each display region is maintained. As a result, a display device
with extremely low power consumption can be obtained.
[0186] Alternatively, silicon is preferably used as a semiconductor
in which the channel of the transistor is formed. Although
amorphous silicon may be used as silicon, silicon having
crystallinity is particularly preferable. For example,
microcrystalline silicon, polycrystalline silicon, single-crystal
silicon, or the like is preferably used. In particular,
polycrystalline silicon can be formed at a lower temperature than
single-crystal silicon and has higher field effect mobility and
higher reliability than amorphous silicon. When such a
polycrystalline semiconductor is used for a pixel, the aperture
ratio of the pixel can be improved. Even in the case where pixels
are provided at extremely high resolution, a scan line driver
circuit and a signal line driver circuit can be formed over a
substrate over which the pixels are formed, and the number of
components of an electronic device can be reduced.
[0187] As a gate, a source, and a drain of a transistor, and a
wiring or an electrode included in a touch panel, any of metals
such as aluminum, titanium, chromium, nickel, copper, yttrium,
zirconium, molybdenum, silver, tantalum, and tungsten, or an alloy
containing any of these metals as its main component can be used. A
single-layer structure or multi-layer structure including a film
containing any of these materials can be used. For example, the
following structures can be given: a single-layer structure of an
aluminum film containing silicon, a two-layer structure in which an
aluminum film is stacked over a titanium film, a two-layer
structure in which an aluminum film is stacked over a tungsten
film, a two-layer structure in which a copper film is stacked over
a copper-magnesium-aluminum alloy film, a two-layer structure in
which a copper film is stacked over a titanium film, a two-layer
structure in which a copper film is stacked over a tungsten film, a
three-layer structure in which a titanium film or a titanium
nitride film, an aluminum film or a copper film, and a titanium
film or a titanium nitride film are stacked in this order, and a
three-layer structure in which a molybdenum film or a molybdenum
nitride film, an aluminum film or a copper film, and a molybdenum
film or a molybdenum nitride film are stacked in this order. Note
that a transparent conductive material containing indium oxide, tin
oxide, or zinc oxide may be used. Copper containing manganese is
preferably used because controllability of a shape by etching is
increased.
[0188] As a light-transmitting material that can be used for
conductive layers such as wirings and electrodes in the touch
panel, a conductive oxide such as indium oxide, indium tin oxide,
indium zinc oxide, zinc oxide, or zinc oxide to which gallium is
added, or graphene can be used. Alternatively, a metal material
such as gold, silver, platinum, magnesium, nickel, tungsten,
chromium, molybdenum, iron, cobalt, copper, palladium, or titanium,
or an alloy material containing any of these metal materials can be
used. Alternatively, a nitride of the metal material (e.g.,
titanium nitride) or the like may be used. In the case of using the
metal material or the alloy material (or the nitride thereof), the
thickness is set small enough to be able to transmit light.
Alternatively, a stack of any of the above materials can be used as
the conductive layer. For example, a stacked film of indium tin
oxide and an alloy of silver and magnesium is preferably used
because the conductivity can be increased.
[0189] Examples of an insulating material that can be used for the
insulating layers, the overcoat, the spacer, and the like include a
resin such as acrylic or epoxy resin, a resin having a siloxane
bond, and an inorganic insulating material such as silicon oxide,
silicon oxynitride, silicon nitride oxide, silicon nitride, or
aluminum oxide.
[0190] The light-emitting element is preferably provided between a
pair of insulating films with low water permeability, in which case
impurities such as water can be prevented from entering the
light-emitting element. Thus, a decrease in device reliability can
be prevented.
[0191] As an insulating film with low water permeability, a film
containing nitrogen and silicon (e.g., a silicon nitride film or a
silicon nitride oxide film), a film containing nitrogen and
aluminum (e.g., an aluminum nitride film), or the like can be used.
Alternatively, a silicon oxide film, a silicon oxynitride film, an
aluminum oxide film, or the like can be used.
[0192] For example, the water vapor transmittance of the insulating
film with low water permeability is lower than or equal to
1.times.10.sup.-5 [g/(m.sup.2day)], preferably lower than or equal
to 1.times.10.sup.-6 [g/(m.sup.2day)], further preferably lower
than or equal to 1.times.10.sup.-7 [g/(m.sup.2day)], still further
preferably lower than or equal to 1.times.10.sup.-8
[g/(m.sup.2day)].
[0193] As the adhesive layers, a variety of curable adhesives such
as a reactive curable adhesive, a thermosetting adhesive, an
anaerobic adhesive, and a photo curable adhesive such as an
ultraviolet curable adhesive can be used. Examples of these
adhesives include an epoxy resin, an acrylic resin, a silicone
resin, a phenol resin, a polyimide resin, an imide resin, a
polyvinyl chloride (PVC) resin, a polyvinyl butyral (PVB) resin,
and an ethylene vinyl acetate (EVA) resin. In particular, a
material with low water permeability, such as an epoxy resin, is
preferable. Alternatively, a two-component-mixture-type resin may
be used. Further alternatively, an adhesive sheet or the like may
be used.
[0194] Further, the resin may include a drying agent. For example,
a substance that adsorbs water by chemical adsorption, such as
oxide of an alkaline earth metal (e.g., calcium oxide or barium
oxide), can be used. Alternatively, a substance that adsorbs water
by physical adsorption, such as zeolite or silica gel, may be used.
The drying agent is preferably included because it can prevent
impurities such as water from entering the functional element,
thereby improving the reliability of the display panel.
[0195] In addition, it is preferable to mix a filler with a high
refractive index or light-scattering member into the resin, in
which case the efficiency of light extraction from the
light-emitting element can be improved. For example, titanium
oxide, barium oxide, zeolite, zirconium, or the like can be
used.
[0196] As the light-emitting element, a self-luminous element can
be used, and an element whose luminance is controlled by current or
voltage is included in the category of the light-emitting element.
For example, a light-emitting diode (LED), an organic EL element,
an inorganic EL element, or the like can be used.
[0197] The light-emitting element may be a top emission, bottom
emission, or dual emission light-emitting element. A conductive
film that transmits visible light is used as the electrode through
which light is extracted. A conductive film that reflects visible
light is preferably used as the electrode through which light is
not extracted.
[0198] The EL layer includes at least a light-emitting layer. In
addition to the light-emitting layer, the EL layer may further
include one or more layers containing any of a substance with a
high hole-injection property, a substance with a high
hole-transport property, a hole-blocking material, a substance with
a high electron-transport property, a substance with a high
electron-injection property, a substance with a bipolar property (a
substance with a high electron- and hole-transport property), and
the like.
[0199] Either a low molecular compound or a high molecular compound
can be used for the EL layer, and an inorganic compound may also be
used. The layers included in the EL layer can be formed by any of
the following methods: an evaporation method (including a vacuum
evaporation method), a transfer method, a printing method, an
inkjet method, a coating method, and the like.
[0200] When a voltage higher than the threshold voltage of the
light-emitting element is applied between the anode and the
cathode, holes are injected to the EL layer from the anode side and
electrons are injected to the EL layer from the cathode side. The
injected electrons and holes are recombined in the EL layer, so
that a light-emitting substance contained in the EL layer emits
light.
[0201] In the case where a light-emitting element emitting white
light is used as the light-emitting element, the EL layer
preferably contains two or more kinds of light-emitting substances.
For example, light-emitting substances are selected so that two or
more light-emitting substances emit complementary colors to obtain
white light emission. Specifically, it is preferable to contain two
or more light-emitting substances selected from light-emitting
substances emitting light of red (R), green (G), blue (B), yellow
(Y), orange (0), and the like and light-emitting substances
emitting light containing two or more of spectral components of R,
G, and B. The light-emitting element preferably emits light with a
spectrum having two or more peaks in the wavelength range of a
visible light region (e.g., 350 nm to 750 nm). An emission spectrum
of a material emitting light having a peak in the wavelength range
of a yellow light preferably includes spectral components also in
the wavelength range of a green light and a red light.
[0202] A light-emitting layer containing a light-emitting material
emitting light of one color and a light-emitting layer containing a
light-emitting material emitting light of another color are
preferably stacked in the EL layer. For example, the plurality of
light-emitting layers in the EL layer may be stacked in contact
with each other or may be stacked with a separation layer
therebetween. For example, between a fluorescent layer and a
phosphorescent layer, a region containing the same material as one
in the fluorescent layer or phosphorescent layer (for example, a
host material or an assist material) and no light-emitting element
may be provided. This facilitates the manufacture of the
light-emitting element and reduces the drive voltage.
[0203] The conductive film that transmits visible light can be
formed using, for example, indium oxide, indium tin oxide (ITO),
indium zinc oxide, zinc oxide, or zinc oxide to which gallium is
added. Alternatively, a film of a metal material such as gold,
silver, platinum, magnesium, nickel, tungsten, chromium,
molybdenum, iron, cobalt, copper, palladium, or titanium; an alloy
containing any of these metal materials; or a nitride of any of
these metal materials (e.g., titanium nitride) can be used when
formed thin so as to have a light-transmitting property.
Alternatively, a stack of any of the above materials can be used as
the conductive layer. For example, a stacked film of ITO and an
alloy of silver and magnesium is preferably used, in which case
conductivity can be increased. Further alternatively, graphene or
the like may be used.
[0204] For the conductive film that reflects visible light, for
example, a metal material, such as aluminum, gold, platinum,
silver, nickel, tungsten, chromium, molybdenum, iron, cobalt,
copper, or palladium or an alloy including any of these metal
materials can be used. Lanthanum, neodymium, germanium, or the like
may be added to the metal material or the alloy. Furthermore, an
alloy containing aluminum (an aluminum alloy) such as an alloy of
aluminum and titanium, an alloy of aluminum and nickel, or an alloy
of aluminum and neodymium; or an alloy containing silver such as an
alloy of silver and copper, an alloy of silver, copper, and
palladium, or an alloy of silver and magnesium can be used for the
conductive film. An alloy of silver and copper is preferable
because of its high heat resistance. Moreover, a metal film or a
metal oxide film is stacked on an aluminum alloy film, whereby
oxidation of the aluminum alloy film can be suppressed. Examples of
a material for the metal film or the metal oxide film are titanium
and titanium oxide. Alternatively, the conductive film having a
property of transmitting visible light and a film containing any of
the above metal materials may be stacked. For example, a stacked
film of silver and ITO or a stacked film of an alloy of silver and
magnesium and ITO can be used.
[0205] The conductive film may be formed separately by an
evaporation method or a sputtering method. Alternatively, a
discharging method such as an ink-jet method, a printing method
such as a screen printing method, or a plating method may be
used.
[0206] The light-emitting element may be a single element including
one EL layer or a tandem element in which a plurality of EL layers
are stacked with a charge generation layer therebetween.
[0207] The above is the descriptions of the components.
[0208] Structure examples which partly differ from the above
cross-sectional structure example 1 will be described below with
reference to drawings. Note that descriptions of the portions
already described are omitted and different portions are described
below.
[Cross-Sectional Structure Example 2]
[0209] FIG. 15 illustrates a cross-sectional structure example of
the touch panel 100 which partly differs from the structure of FIG.
14.
[0210] In FIG. 15, in the transistors 201 and 202, conductive
layers functioning as the second gates are provided between the
insulating layer 213 and the insulating layer 214. Such a structure
is preferable because the voltage to be applied to the second gates
can be lowered as compared with the structure in FIG. 14.
[0211] FIG. 15 illustrates an example where the display element 60
is formed by a separate coloring method. Specifically, pixels of
different colors include different EL layers 222 which emit light
of the respective colors. In a region outside the light-emitting
region of the display element 60, an end portion of the EL layer
222 is covered with the second electrode 223. The EL layer 222 can
be formed by, for example, an evaporation method using a metal
mask, a printing method, an inkjet method, or the like.
[0212] In the example illustrated in FIG. 15, the optical
adjustment layer 224 and the coloring layer 231 illustrated in FIG.
14 are not provided.
[0213] FIG. 15 shows an example where a protection film 217 is
provided to cover the second electrode 223. The protection film 217
serves as a barrier film that prevents impurities such as water
from diffusing into the display element 60. Although not
illustrated in the drawing, an end portion of the EL layer 222 or
an end portion of the second electrode 223 is covered with the
protection film 217, whereby entry of water into the display
element 60 can be more effectively inhibited.
[0214] As the protection film 217, an organic insulation material
or an inorganic insulation material can be used. An inorganic
insulation material is preferably used because a film with a high
barrier property can be formed to be thin. When an inorganic
insulation material is used as the protection film 217, silicon
nitride, silicon nitride oxide, aluminum oxide, aluminum
oxynitride, aluminum nitride oxide, aluminum nitride, hafnium
oxide, or the like is preferably used. Aluminum oxide is
particularly preferable because of its excellent barrier property.
As a deposition method of the protection film 217, a sputtering
method, an evaporation method, a chemical vapor deposition (CVD)
method, an atomic layer deposition (ALD) method, or the like can be
used. The ALD method is particularly preferable to inhibit damage
to the display element 60 at the time of deposition. Although a
thermal ALD method can be used as the ALD method, a plasma enhanced
ALD (PEALD) method is more preferable because a film can be formed
at low temperatures around room temperature.
[0215] Note that the structures of the transistors, the display
elements 60, the protection film 217, and the like can be replaced
with those of the transistors, the display elements and the like
shown in FIG. 14 and cross-sectional structures described
below.
[Cross-Sectional Structure Example 3]
[0216] A touch panel illustrated in FIG. 16 includes a substrate
111 and a substrate 112. The substrate 111 and the substrate 72 are
attached to each other with the adhesive layer 152, and the
substrate 111 and the substrate 112 are attached to each other with
an adhesive layer 153.
[0217] The substrate 111 is provided with the electrode 32, the
wiring 42, and the like. The substrate 112 is provided with the
electrode 31, the wiring 41 (not illustrated), and the like. In
FIG. 16, the FPC 50 is provided for the substrate 111; the
substrate 112 is similarly provided with an FPC in a region not
illustrated in the drawing.
[0218] In the case where two substrates are used in the structure
of the input device 10 as described above, substrates as thin as,
or thinner than, the substrates 71 and 72 are preferably used as
the substrates 111 and 112. In particular, the material having
flexibility described above is preferably used for the substrates
111 and 112, in which case the thickness of the touch panel 100 can
be decreased.
[0219] A protective substrate 130 may be provided over the
substrate 112 with an adhesive layer 154 therebetween as
illustrated in FIG. 16. A surface of the protective substrate 130
on a side opposite to the substrate 112 side functions as a touch
surface. The above description of the substrate 30 can be referred
to for a material of the protective substrate 130.
[Cross-Sectional Structure Example 4]
[0220] A touch panel shown in FIG. 17 includes a substrate 113. The
substrates 113 and 72 are attached to each other with the adhesive
layer 152.
[0221] The substrate 113 is provided with the electrode 32, the
wiring 42, and the like on one side. The substrate 113 is also
provided with the electrode 31, the wiring 41, and the like on the
other side. That is, the electrodes and wirings in the touch sensor
are provided on both sides of the substrate 113.
[0222] FIG. 17 illustrates an example in which an FPC 50a and a
connection layer 109a are provided in a connection portion 106a
where part of the wiring 42 is exposed, and an FPC 50b and a
connection layer 109b are provided in a connection portion 106b
where part of the wiring 41 is exposed. Note that the connection
portion 106a and the connection portion 106b may overlap with each
other in a plan view, or may be arranged so as not to overlap with
each other.
[Cross-Sectional Structure Example 5]
[0223] In a touch panel illustrated in FIG. 18, the electrodes and
the like of the touch sensor are provided over a surface of the
substrate 72 that is opposite to a surface facing the substrate 71.
Specifically, the substrate 72 is provided with the bridge
electrode 34, and the insulating layer 161 covering part of the
bridge electrode 34; and the electrode 31, the electrode 32, the
wiring 41 (not illustrated), the wiring 42, and the like are over
the insulating layer 161.
[0224] As illustrated in FIG. 18, the protective substrate 130 and
the substrate 72 may be attached to each other with the adhesive
layer 152.
[0225] In this structure, the input device 10 and the display panel
70 can share the substrate; thus, the thickness of the touch panel
can be significantly decreased.
[Cross-Sectional Structure Example 6]
[0226] FIG. 19 illustrates an example in which the structure of the
touch sensor illustrated in FIG. 18 is combined with the structure
of the touch panel illustrated in FIG. 15 where the light-emitting
element formed by a separate coloring method is used as the display
element 60. In the example illustrated in FIG. 19, the
light-blocking layer 232 is not provided.
[Cross-Sectional Structure Example 7]
[0227] In a touch panel illustrated in FIG. 20, the electrodes and
the like of the touch sensor are provided on the substrate 71 side
of the substrate 72. Specifically, the substrate 72 is provided
with the electrode 32, the electrode 33, the wiring 41 (not
illustrated), the wiring 42, the insulating layer 161 covering
these components, and the bridge electrode 34 over the insulating
layer 161, and the like.
[0228] An insulating layer 233 is provided to cover the electrodes
and the like in the touch sensor. In addition, the coloring layer
231, the light-blocking layer 232, and the like are provided over
the insulating layer 233.
[0229] In this structure, the input device 10 and the display panel
70 can share the substrate and one surface of the substrate 72 can
be used as a touch surface; thus, the thickness of the touch panel
100 can be further decreased.
[Cross-Sectional Structure Example 8]
[0230] FIG. 21 illustrates a modification example of the touch
panel shown in FIG. 20.
[0231] The touch panel in FIG. 21 has a stacked-layer structure
including a substrate 91, an adhesive layer 92, a substrate 93, and
an insulating layer 94 in place of the substrate 71. The touch
panel also has a stacked-layer structure including a substrate 191,
an adhesive layer 192, a substrate 193, and an insulating layer 194
in place of the substrate 72.
[0232] A material through which impurities such as water or
hydrogen do not easily diffuse can be used for the insulating layer
94 and the insulating layer 194. Such a structure can effectively
suppress diffusion of the impurities into the display element 60
and the transistors even in the case of using a material permeable
to water for the substrate 91, the substrate 93, the substrate 191,
and the substrate 193, and a highly reliable touch panel can be
achieved.
[0233] A material such as a resin having flexibility can be used
for the substrate 93 and the substrate 193. Films having
flexibility or the like are preferably used as the substrate 91 and
the substrate 191. With the use of a material having flexibility
for these substrates, a bendable touch panel can be achieved.
[Cross-Sectional Structure Example 9]
[0234] In a touch panel illustrated in FIG. 22, the light-blocking
layer 232 is provided between the electrodes and the like of the
touch sensor and the substrate 72. Specifically, the substrate 72
is provided with the light-blocking layer 232, and an insulating
layer 234 is formed to cover the light-blocking layer 232. The
electrode 32, the electrode 33, the wiring 41 (not illustrated),
the wiring 42, the insulating layer 161 covering these components,
and the bridge electrode 34 riding the insulating layer 161, and
the like are provided for an insulating layer 234. In addition, the
insulating layer 233 is formed to ride the bridge electrode 34 and
the insulating layer 161, and the coloring layer 231 is formed to
ride the insulating layer 233, and the like.
[0235] The insulating layers 233 and 234 have a function as a
planarization film. Note that the insulating layer 233 and 234 are
not necessarily provided when not needed.
[0236] With such a structure, the light-blocking layer 232 provided
in a position closer to the viewing side than the electrodes and
the like of the touch sensor is can prevent external light from
being reflected by the electrodes and the like, and prevent the
electrodes and the like from being visible. Thus, a touch panel
with not only small thickness but also improved visibility can be
achieved.
[Cross-Sectional Structure Example 10]
[0237] FIG. 23 illustrates a modification example of the touch
panel illustrated in FIG. 22.
[0238] The touch panel in FIG. 23 has a stacked-layer structure
including the substrate 91, the adhesive layer 92, and the
insulating layer 94 in place of the substrate 71. The touch panel
also has a stacked-layer structure including the substrate 191, the
adhesive layer 192, and the insulating layer 194 in place of the
substrate 72.
[0239] With the use of a material having flexibility for the
substrates 91 and 191, a bendable touch panel can be achieved.
[Cross-Sectional Structure Example 11]
[0240] FIG. 24 illustrates a cross-sectional structure example of a
touch panel where a liquid crystal display device is used as the
display panel 70. In the touch panel illustrated in FIG. 24, a
liquid crystal element is used as a display element 208. The touch
panel includes a polarizing plate 131, a polarizing plate 132, and
a backlight 133.
[0241] In the example illustrated here, a liquid crystal element
using a fringe field switching (FFS) mode is used as the display
element 208. The display element 208 includes an electrode 251, an
electrode 252, and a liquid crystal 253. The electrode 251 is
provided over the electrode 252 with an insulating layer 254
provided therebetween, and has a comb-like shape or a shape
provided with a slit.
[0242] An overcoat 255 is provided to cover the coloring layer 231
and the light-blocking layer 232. The overcoat 255 has a function
of preventing a pigment or the like which is included in the
coloring layer 231 or the light-blocking layer 232 from diffusing
into the liquid crystal 253.
[0243] Surfaces of the overcoat 255, the insulating layer 254, the
electrode 251, and the like which are in contact with the liquid
crystal 253 may be provided with alignment films for controlling
the orientation of the liquid crystal 253.
[0244] In FIG. 24, the polarizing plate 131 is attached to the
substrate 71 with an adhesive layer 157. The backlight 133 is
attached to the polarizing plate 131 with an adhesive layer 158.
The polarizing plate 132 is positioned between the substrate 72 and
the substrate 30. The polarizing plate 132 is attached to the
substrate 72 with an adhesive layer 155, and is attached to the
substrate 30 (specifically, part of the insulating layer 161
provided with the substrate 30) with an adhesive layer 156.
[0245] Although the liquid crystal element using an FFS mode is
described above, a vertical alignment (VA) mode, a twisted nematic
(TN) mode, an in-plane-switching (IPS) mode, an axially symmetric
aligned micro-cell (ASM) mode, an optically compensated
birefringence (OCB) mode, a ferroelectric liquid crystal (FLC)
mode, an antiferroelectric liquid crystal (AFLC) mode, or the like
can be used.
[0246] As the liquid crystal, a thermotropic liquid crystal, a
low-molecular liquid crystal, a high-molecular liquid crystal, a
ferroelectric liquid crystal, an anti-ferroelectric liquid crystal,
a polymer dispersed liquid crystal (PDLC), or the like can be used.
Moreover, a liquid crystal exhibiting a blue phase is preferably
used because an alignment film is not needed and a wide viewing
angle is obtained in that case.
[Cross-Sectional Structure Example 12]
[0247] FIG. 25 illustrates a cross-sectional structure example of a
touch panel where a liquid crystal display device is used as the
display panel 70. In the touch panel illustrated in FIG. 25, the
polarizing plate 132 is provided in a position closer to the
viewing side than that of the electrodes and the like in the touch
sensor. Specifically, a substrate 114 provided with the electrode
31, the electrode 32, and the like is attached to the substrate 72
with the adhesive layer 152, and the polarizing plate 132 is
attached to the substrate 114 with the adhesive layer 155. The
protective substrate 130 attached to the polarizing plate 132 with
the adhesive layer 156 is provided in a position closer to the
viewing side than that of the polarizing plate 132.
[0248] A film having flexibility or the like is preferably used as
the substrate 114 because the thickness of the touch panel can be
decreased.
[Cross-Sectional Structure Example 13]
[0249] FIG. 26 illustrates a cross-sectional structure example of a
touch panel where a liquid crystal display device is used as the
display panel. In the example of the touch panel illustrated in
FIG. 26, the electrodes and the like of the touch sensor are formed
on the substrate 71 side of the substrate 72. Specifically, the
substrate 72 is provided with the electrode 32, the electrode 33,
the wiring 41 (not illustrated), the wiring 42, the insulating
layer 161 covering these components, and the bridge electrode 34
riding the insulating layer 161, and the like. The insulating layer
233 is formed to cover the electrodes and the like of the touch
sensor. In addition, the coloring layer 231, the light-blocking
layer 232, and the like are formed over the insulating layer
233.
[0250] The polarizing plate 132 is attached to the opposite side of
the substrate 72 with the adhesive layer 155. The protective
substrate 130 is attached to the polarizing plate 132 with the
adhesive layer 156.
[0251] In this structure, the input device and the display panel
can share the substrate and one surface of the substrate 72 can be
used as a touch surface; thus, the thickness of the touch panel can
be further decreased.
[Cross-Sectional Structure Example 14]
[0252] FIG. 27 illustrates a cross-sectional structure example of a
touch panel where a liquid crystal display device is used as the
display panel. In the example of the touch panel illustrated in
FIG. 27, the electrodes and the like of the touch sensor are
provided on a side of the substrate 72 opposite to the substrate 71
side. Specifically, the bridge electrode 34 is formed over a
surface of the substrate 72 on a side opposite to the side where
the coloring layer 231 and the like are provided; the insulating
layer 161 is formed to cover part of the bridge electrode 34; and
the electrode 31, the electrode 32, the wiring 41 (not
illustrated), the wiring 42, and the like are formed over the
insulating layer 161. The polarizing plate 132 is attached to the
substrate 72 with the adhesive layer 152, and the protective
substrate 130 is attached to the polarizing plate 132 with the
adhesive layer 156.
[0253] The above is the description of the cross-sectional
structure examples.
[Example of Manufacturing Method]
[0254] Here, a method for manufacturing a flexible touch panel is
described.
[0255] For convenience, a structure including a pixel and a
circuit, a structure including an optical member such as a color
filter, a structure including an electrode or a wiring of a touch
sensor, or the like is referred to as an element layer. An element
layer includes a display element, for example, and may include a
wiring electrically connected to a display element or an element
such as a transistor used in a pixel or a circuit in addition to
the display element.
[0256] Here, a support body (e.g., the substrate 91 or the
substrate 191 in FIG. 23) with an insulating surface where an
element layer is formed is referred to as a substrate.
[0257] As a method for forming an element layer over a flexible
substrate provided with an insulating surface, there are a method
in which an element layer is formed directly over a substrate, and
a method in which an element layer is formed over a supporting base
material that has stiffness and then the element layer is separated
from the supporting base material and transferred to the
substrate.
[0258] In the case where a material of the substrate can withstand
heating temperature in a process for forming the element layer, it
is preferable that the element layer be formed directly over the
substrate, in which case a manufacturing process can be simplified.
At this time, the element layer is preferably formed in a state
where the substrate is fixed to a supporting base material, in
which case transfer thereof in an apparatus and between apparatuses
can be easy.
[0259] In the case of employing the method in which the element
layer is formed over the supporting base material and then
transferred to the substrate, first, a separation layer and an
insulating layer are stacked over the supporting base material, and
then the element layer is formed over the insulating layer. Next,
the element layer is separated from the supporting base material
and then transferred to the substrate. At this time, selected is a
material with which separation at an interface between the
supporting base material and the separation layer, at an interface
between the separation layer and the insulating layer, or in the
separation layer occurs.
[0260] For example, it is preferable that a stacked layer of a
layer including a high-melting-point metal material, such as
tungsten, and a layer including an oxide of the metal material be
used as the insulating layer as the separation layer, and a stacked
layer of a plurality of layers, such as a silicon nitride layer and
a silicon oxynitride layer be used as the insulating layer over the
separation layer. The use of the high-melting-point metal material
is preferable because the degree of freedom of the process for
forming the element layer can be increased.
[0261] The separation may be performed by application of mechanical
power, by etching of the separation layer, by dripping of a liquid
into part of the separation interface to penetrate the entire
separation interface, or the like. Alternatively, separation may be
performed by heating the separation interface by utilizing a
difference in thermal expansion coefficient.
[0262] The separation layer is not necessarily provided in the case
where separation can occur at an interface between the supporting
base material and the insulating layer. For example, glass and an
organic resin such as polyimide may be used as the supporting base
material and the insulating layer, respectively, and a separation
trigger may be formed by locally heating part of the organic resin
by laser light or the like, so that separation may be performed at
an interface between the glass and the insulating layer.
Alternatively, a metal layer may be provided between the supporting
base material and the insulating layer formed of an organic resin,
and separation may be performed at the interface between the metal
layer and the insulating layer formed of an organic resin by
heating the metal layer by feeding current to the metal layer. A
layer of a light-absorbing material (e.g., a metal, a
semiconductor, or an insulator) may be provided between the
supporting base layer and the insulating layer formed of an organic
resin and locally heated with laser light or the like to form a
separation trigger. In these methods, the insulating layer formed
of an organic resin can be used as a substrate.
[0263] Examples of such a substrate having flexibility include
polyester resins such as polyethylene terephthalate (PET) and
polyethylene naphthalate (PEN), a polyacrylonitrile resin, a
polyimide resin, a polymethyl methacrylate resin, a polycarbonate
(PC) resin, a polyethersulfone (PES) resin, a polyamide resin, a
cycloolefin resin, a polystyrene resin, a polyamide imide resin,
and a polyvinyl chloride resin. In particular, a material whose
thermal expansion coefficient is low, for example, lower than or
equal to 30.times.10.sup.-6/K is preferable, and a polyamide imide
resin, a polyimide resin, or PET can be suitably used. A substrate
in which a fibrous body is impregnated with a resin (also referred
to as prepreg) or a substrate whose thermal expansion coefficient
is reduced by mixing an inorganic filler with an organic resin can
also be used.
[0264] In the case where a fibrous body is included in the above
material, a high-strength fiber of an organic compound or an
inorganic compound is used as the fibrous body. The high-strength
fiber is specifically a fiber with a high tensile elastic modulus
or a fiber with a high Young's modulus. Typical examples thereof
include a polyvinyl alcohol based fiber, a polyester based fiber, a
polyamide based fiber, a polyethylene based fiber, an aramid based
fiber, a polyparaphenylene benzobisoxazole fiber, a glass fiber,
and a carbon fiber. As the glass fiber, glass fiber using E glass,
S glass, D glass, Q glass, or the like can be used. These fibers
may be used in a state of a woven fabric or a nonwoven fabric, and
a structure body in which this fibrous body is impregnated with a
resin and the resin is cured may be used as the flexible substrate.
The structure body including the fibrous body and the resin is
preferably used as the flexible substrate, in which case the
reliability against bending or breaking due to local pressure can
be increased.
[0265] Alternatively, glass, metal, or the like that is thin enough
to have flexibility can be used as the substrate. Alternatively, a
composite material where glass and a resin material are attached to
each other may be used.
[0266] In the structure shown in FIG. 23, for example, a first
separation layer and the insulating layer 94 are formed in this
order over a first supporting base material, and then components
over the first separation layer and the insulating layer 94 are
formed. Separately, a second separation layer and the insulating
layer 194 are formed in this order over a second supporting base
material, and then upper components are formed. Next, the first
supporting base material and the second supporting base material
are attached to each other with the adhesive layer 151. After that,
separation at an interface between the second separation layer and
the insulating layer 194 is conducted so that the second supporting
base material and the second separation layer are removed, and then
the substrate 191 is attached to the insulating layer 194 with the
adhesive layer 192. Further, separation at an interface between the
first separation layer and the insulating layer 94 is conducted so
that the first supporting base material and the first separation
layer are removed, and then the substrate 91 is attached to the
insulating layer 94 with the adhesive layer 92. Note that either
side may be subjected to separation and attachment first.
[0267] The above is the description of a manufacturing method of a
flexible touch panel.
[0268] Although a light-emitting element and a liquid crystal
element are used as a display element here, one embodiment of the
present invention is not limited thereto.
[0269] For example, a display element such as a micro electro
mechanical system (MEMS) element or an electron-emissive element
can be used in the display device. Examples of MEMS display
elements include a MEMS shutter display element, an optical
interference type MEMS display element, and the like. A carbon
nanotube may be used for the electron-emissive element.
Alternatively, electronic paper may be used. As the electronic
paper, an element using a microcapsule method, an electrophoretic
method, an electrowetting method, an Electronic Liquid Powder
(registered trademark) method, or the like can be used.
[0270] At least part of this embodiment can be implemented in
combination with any of the embodiments described in this
specification as appropriate.
Embodiment 2
[0271] In this embodiment, examples of a driving method of an input
device or an input/output device of one embodiment of the present
invention are described with reference to drawings.
[Example of Sensing Method of Sensor]
[0272] FIG. 28A is a block diagram illustrating the structure of a
mutual capacitive touch sensor. FIG. 28A illustrates a pulse
voltage output circuit 601 and a current sensing circuit 602. Note
that in FIG. 28A, six wirings X1 to X6 represent electrodes 621 to
which a pulse voltage is applied, and six wirings Y1 to Y6
represent electrodes 622 that sense changes in current. FIG. 28A
also illustrates a capacitor 603 that is formed where electrodes
621 and 622 overlap with each other. Note that functional
replacement between the electrodes 621 and 622 is possible.
[0273] The pulse voltage output circuit 601 is a circuit for
sequentially applying a pulse voltage to the wirings X1 to X6. By
application of a pulse voltage to the wirings X1 to X6, an electric
field is generated between the electrodes 621 and 622 of the
capacitor 603. When the electric field between the electrodes is
shielded, for example, a change occurs in mutual capacitance of the
capacitor 603. The approach or contact of an object can be sensed
by utilizing this change.
[0274] The current sensing circuit 602 is a circuit for sensing
changes in current flowing through the wirings Y1 to Y6 that are
caused by the change in capacitance in the capacitor 603. No change
in current value is sensed in the wirings Y1 to Y6 when there is no
approach or contact of an object, whereas a decrease in current
value is sensed when capacitance is decreased owing to the approach
or contact of an object. Note that an integrator circuit or the
like is used for sensing of current values.
[0275] FIG. 28B is a timing chart showing input and output
waveforms in the mutual capacitive touch sensor illustrated in FIG.
28A. In FIG. 28B, detection of an object is performed in all the
rows and columns in one frame period. FIG. 28B shows a period when
an object is not detected (not touched) and a period when an object
is detected (touched). Sensed current values of the wirings Y1 to
Y6 are shown as waveforms of voltage values.
[0276] A pulse voltage is sequentially applied to the wirings X1 to
X6, and waveforms of the wirings Y1 to Y6 change in accordance with
the pulse voltage. When there is no proximity or contact of an
object, the waveforms of the wirings Y1 to Y6 change in accordance
with changes in the voltages of the wirings X1 to X6. The current
value is decreased at the point of approach or contact of the
object and accordingly the waveform of the voltage value
changes.
[0277] By sensing a change in mutual capacitance in this manner,
proximity or contact of an object can be sensed.
[0278] It is preferable that the pulse voltage output circuit 601
and the current sensing circuit 602 be mounted on a substrate in a
housing of an electronic appliance or on the touch panel in the
form of an IC. In the case where the touch panel has flexibility,
parasitic capacitance might be increased in a bent portion of the
touch panel, and the influence of noise might be increased. In view
of this, it is preferable to use an IC to which a driving method
less influenced by noise is applied. For example, it is preferable
to use an IC to which a driving method capable of increasing a
signal-noise ratio (S/N ratio) is applied.
[0279] Although FIG. 28A is a passive matrix type touch sensor in
which only the capacitor 603 is provided at the intersection
portion of wirings as a touch sensor, an active matrix type touch
sensor including a transistor and a capacitor may be used. FIG. 29
is a sensor circuit included in an active matrix type touch
sensor.
[0280] The sensor circuit includes the capacitor 603 and
transistors 611, 612, and 613. A signal G2 is input to a gate of
the transistor 613. A voltage VRES is applied to one of a source
and a drain of the transistor 613, and one electrode of the
capacitor 603 and a gate of the transistor 611 are electrically
connected to the other of the source and the drain of the
transistor 613. One of a source and a drain of the transistor 611
is electrically connected to one of a source and a drain of the
transistor 612, and a voltage VSS is applied to the other of the
source and the drain of the transistor 611. A signal G1 is input to
a gate of the transistor 612, and a wiring ML is electrically
connected to the other of the source and the drain of the
transistor 612. The voltage VSS is applied to the other electrode
of the capacitor 603.
[0281] Next, the operation of the sensor circuit will be described.
First, a potential for turning on the transistor 613 is supplied as
the signal G2, and a potential with respect to the voltage VRES is
thus applied to the node n connected to the gate of the transistor
611. Then, a potential for turning off the transistor 613 is
applied as the signal G2, whereby the potential of the node n is
maintained.
[0282] Then, capacitance of the capacitor 603 changes owing to the
approach or contact of an object such as a finger, and accordingly
the potential of the node n is changed from VRES.
[0283] In reading operation, a potential for turning on the
transistor 612 is supplied as the signal G1. A current flowing
through the transistor 611, that is, a current flowing through the
wiring ML is changed in accordance with the potential of the node
n. By sensing this current, the approach or contact of an object
can be detected.
[0284] It is preferable that the transistors 611, 612, and 613 each
include an oxide semiconductor in a semiconductor layer where a
channel is formed. In particular, by using an oxide semiconductor
in a semiconductor layer where a channel of the transistor 613 is
formed, the potential of the node n can be held for a long time and
the frequency of operation (refresh operation) of resupplying VRES
to the node n can be reduced.
[Structure Example of in-Cell Touch Panel]
[0285] Although the examples where the electrodes in the touch
sensor are formed over a substrate different from a substrate where
the display element and the like are provided are described above,
one or both of the pair of electrodes in the touch sensor may be
formed over the substrate where the display element and the like
are provided.
[0286] A structural example of a touch panel incorporating the
touch sensor into a display portion including a plurality of pixels
is described below. Here, an example where a liquid crystal element
is used as a display element provided in the pixel is shown.
[0287] FIG. 30A is an equivalent circuit diagram of part of a pixel
circuit provided in the display portion of the touch panel in this
structure example.
[0288] Each pixel includes at least a transistor 3503 and a liquid
crystal element 3504. In addition, a gate of the transistor 3503 is
electrically connected to a wiring 3501, and one of a source and a
drain of the transistor 3503 is electrically connected to a wiring
3502.
[0289] The pixel circuit includes a plurality of wirings extending
in the X direction (e.g., a wiring 3510_1 and a wiring 3510_2) and
a plurality of wirings extending in the Y direction (e.g., a wiring
3511). These wirings are provided to intersect with each other, and
capacitance is formed therebetween.
[0290] Among the pixels provided in the pixel circuit, electrodes
on one side of the liquid crystal elements of some pixels adjacent
to each other are electrically connected to each other to form one
block. The block is classified into two types: an island-shaped
block (e.g., a block 3515_1 or a block 3515_2) and a linear block
(e.g., a block 3516) extending in the Y direction. Note that only
part of the pixel circuit is illustrated in FIGS. 30A and 30B, but
actually, these two kinds of blocks are repeatedly arranged in the
X direction and the Y direction.
[0291] The wiring 3510_1 (or 3510_2) extending in the X direction
is electrically connected to the island-shaped block 3515_1 (or the
block 3515_2). Although not illustrated, the wiring 3510_1
extending in the X direction is electrically connected to a
plurality of island-shaped blocks 3515_1 which are provided
discontinuously along the X direction with the linear blocks
therebetween. Further, the wiring 3511 extending in the Y direction
is electrically connected to the linear block 3516.
[0292] FIG. 30B is an equivalent circuit diagram illustrating the
connection between a plurality of wirings 3510 extending in the X
direction and the plurality of wirings 3511 extending in the Y
direction. An input voltage or a common potential can be input to
each of the wirings 3510 extending in the X direction. Further, a
ground potential can be input to each of the wirings 3511 extending
in the Y direction, or the wirings 3511 can be electrically
connected to the sensing circuit.
[0293] Operation of the above-described touch panel is described
with reference to FIGS. 31A and 31B.
[0294] Here, one frame period is divided into a writing period and
a sensing period. The writing period is a period in which image
data is written to a pixel, and the wirings 3510 (also referred to
as gate lines or scan lines) are sequentially selected. On the
other hand, the sensing period is a period in which sensing is
performed by a touch sensor, and the wirings 3510 extending in the
X direction are sequentially selected and an input voltage is
input.
[0295] FIG. 31A is an equivalent circuit diagram in the writing
period. In the writing period, a common potential is input to both
the wiring 3510 extending in the X direction and the wiring 3511
extending in the Y direction.
[0296] FIG. 31B is an equivalent circuit diagram at a certain point
of time in the sensing period. In the sensing period, each of the
wirings 3511 extending in the Y direction is electrically connected
to the sensing circuit. An input voltage is input to the wirings
3510 extending in the X direction which are selected, and a common
potential is input to the wirings 3510 extending in the X direction
which are not selected.
[0297] Note that the driving method described here can be applied
to not only an in-cell touch panel but also the above-described
touch panels, and can be used in combination with the method
described in the driving method example.
[0298] It is preferable that a period in which an image is written
and a period in which sensing is performed by a touch sensor be
separately provided as described above. Thus, a decrease in
sensitivity of the touch sensor caused by noise generated when data
is written to a pixel can be suppressed.
Embodiment 3
[0299] In this embodiment, electronic devices and lighting devices
of one embodiment of the present invention will be described with
reference to drawings.
[0300] Electronic devices and lighting devices can be manufactured
by using the input device, the display device, or the input/output
device of one embodiment of the present invention. Highly reliable
electronic devices and lighting devices with curved surfaces can be
manufactured by using the input device, the display device, or the
input/output device of one embodiment of the present invention. In
addition, flexible and highly reliable electronic devices and
lighting devices can be manufactured by using the input device, the
display device, or the input/output device of one embodiment of the
present invention. Furthermore, electronic devices and lighting
devices including touch sensors with improved detection sensitivity
and sensing accuracy can be manufactured by using the input device
or the input/output device of one embodiment of the present
invention.
[0301] Examples of electronic devices include a television set
(also referred to as a television or a television receiver), a
monitor of a computer or the like, a digital camera, a digital
video camera, a digital photo frame, a mobile phone (also referred
to as a mobile phone device), a portable game machine, a portable
information terminal, an audio reproducing device, a large game
machine such as a pinball machine, and the like.
[0302] The electronic device or the lighting device of one
embodiment of the present invention has flexibility and therefore
can be incorporated along a curved inside/outside wall surface of a
house or a building or a curved interior/exterior surface of a
car.
[0303] Furthermore, the electronic device of one embodiment of the
present invention may include a secondary battery. It is preferable
that the secondary battery be capable of being charged by
contactless power transmission.
[0304] As examples of the secondary battery, a lithium ion
secondary battery such as a lithium polymer battery (lithium ion
polymer battery) using a gel electrolyte, a lithium ion battery, a
nickel-hydride battery, a nickel-cadmium battery, an organic
radical battery, a lead-acid battery, an air secondary battery, a
nickel-zinc battery, and a silver-zinc battery can be given.
[0305] The electronic device of one embodiment of the present
invention may include an antenna. When a signal is received by the
antenna, the electronic device can display an image, data, or the
like on a display portion. When the electronic device includes a
secondary battery, the antenna may be used for contactless power
transmission.
[0306] FIGS. 32A, 32B, 32C1, 32C2, 32D, and 32E illustrate examples
of an electronic device including a display portion 7000 with a
curved surface. The display surface of the display portion 7000 is
bent, and images can be displayed on the bent display surface. The
display portion 7000 may be flexible.
[0307] The display portion 7000 can be formed using the display
device, the input/output device, or the like of one embodiment of
the present invention. One embodiment of the present invention
makes it possible to provide a highly reliable electronic device
having a curved display portion.
[0308] FIG. 32A illustrates an example of a mobile phone. A mobile
phone 7100 includes a housing 7101, the display portion 7000,
operation buttons 7103, an external connection port 7104, a speaker
7105, a microphone 7106, and the like.
[0309] The mobile phone 7100 illustrated in FIG. 32A includes a
touch sensor in the display portion 7000. Moreover, operations such
as making a call and inputting a letter can be performed by touch
on the display portion 7000 with a finger, a stylus, or the
like.
[0310] With the operation buttons 7103, power ON or OFF can be
switched. In addition, types of images displayed on the display
portion 7000 can be switched; for example, switching from a mail
creation screen to a main menu screen can be performed.
[0311] FIG. 32B illustrates an example of a television set. In a
television set 7200, the display portion 7000 is incorporated into
a housing 7201. Here, the housing 7201 is supported by a stand
7203.
[0312] The television set 7200 illustrated in FIG. 32B can be
operated with an operation switch of the housing 7201 or a separate
remote controller 7211. The display portion 7000 may include a
touch sensor. The display portion 7000 can be operated by touching
the display portion with a finger or the like. The remote
controller 7211 may be provided with a display portion for
displaying data output from the remote controller 7211. With
operation keys or a touch panel of the remote controller 7211,
channels and volume can be controlled and images displayed on the
display portion 7000 can be controlled.
[0313] The television set 7200 is provided with a receiver, a
modem, and the like. A general television broadcast can be received
with the receiver. When the television set is connected to a
communication network with or without wires via the modem, one-way
(from a transmitter to a receiver) or two-way (between a
transmitter and a receiver or between receivers) data communication
can be performed.
[0314] FIGS. 32C1, 32C2, 32D, and 32E illustrate examples of a
portable information terminal Each of the portable information
terminals includes a housing 7301 and the display portion 7000.
Each of the portable information terminals may also include an
operation button, an external connection port, a speaker, a
microphone, an antenna, a battery, or the like. The display portion
7000 is provided with a touch sensor. An operation of the portable
information terminal can be performed by touching the display
portion 7000 with a finger, a stylus, or the like.
[0315] FIG. 32C1 is a perspective view of a portable information
terminal 7300. FIG. 32C2 is a top view of the portable information
terminal 7300. FIG. 32D is a perspective view of a portable
information terminal 7310. FIG. 32E is a perspective view of a
portable information terminal 7320.
[0316] Each of the portable information terminals illustrated in
this embodiment functions as, for example, one or more of a
telephone set, a notebook, and an information browsing system.
Specifically, the portable information terminals each can be used
as a smartphone. Each of the portable information terminals
illustrated in this embodiment is capable of executing a variety of
applications such as mobile phone calls, e-mailing, reading and
editing texts, music reproduction, Internet communication, and a
computer game, for example.
[0317] The portable information terminals 7300, 7310, and 7320 can
display characters and image information on its plurality of
surfaces. For example, as illustrated in FIGS. 32C1 and 32D, three
operation buttons 7302 can be displayed on one surface, and
information 7303 indicated by a rectangle can be displayed on
another surface. FIGS. 32C1 and 32C2 illustrate an example in which
information is displayed at the top of the portable information
terminal. FIG. 32D illustrates an example in which information is
displayed on the side of the portable information terminal.
Information may be displayed on three or more surfaces of the
portable information terminal FIG. 32E illustrates an example where
information 7304, information 7305, and information 7306 are
displayed on different surfaces.
[0318] Examples of the information include notification from a
social networking service (SNS), display indicating reception of an
e-mail or an incoming call, the title of an e-mail or the like, the
sender of an e-mail or the like, the date, the time, remaining
battery, and the reception strength of an antenna. Alternatively,
the operation button, an icon, or the like may be displayed instead
of the information.
[0319] For example, a user of the portable information terminal
7300 can see the display (here, the information 7303) on the
portable information terminal 7300 put in a breast pocket of
his/her clothes.
[0320] Specifically, a caller's phone number, name, or the like of
an incoming call is displayed in a position that can be seen from
above the portable information terminal 7300. Thus, the user can
see the display without taking out the portable information
terminal 7300 from the pocket and decide whether to answer the
call.
[0321] FIGS. 32F to 32H each illustrate an example of a lighting
device having a curved light-emitting portion.
[0322] The light-emitting portion included in each of the lighting
devices illustrated in FIGS. 32F to 32H can be manufactured using
the display device, an input/output device, or the like of one
embodiment of the present invention. According to one embodiment of
the present invention, a highly reliable lighting device having a
curved light-emitting portion can be provided.
[0323] A lighting device 7400 illustrated in FIG. 32F includes a
light-emitting portion 7402 with a wave-shaped light-emitting
surface and thus is a good-design lighting device.
[0324] A light-emitting portion 7412 included in the lighting
device 7410 illustrated in FIG. 32G has two convex-curved
light-emitting portions symmetrically placed. Thus, all directions
can be illuminated with the lighting device 7410 as a center.
[0325] A lighting device 7420 illustrated in FIG. 32H includes a
concave-curved light-emitting portion 7422. This is suitable for
illuminating a specific range because light emitted from the
concave-curved light-emitting portion 7422 is collected to the
front of the lighting device 7420. In addition, with this
structure, a shadow is less likely to be produced.
[0326] The light-emitting portion included in each of the lighting
devices 7400, 7410 and 7420 may be flexible. The light-emitting
portion may be fixed on a plastic member, a movable frame, or the
like so that a light-emitting surface of the light-emitting portion
can be bent freely depending on the intended use.
[0327] The lighting devices 7400, 7410, and 7420 each include a
stage 7401 provided with an operation switch 7403 and the
light-emitting portion supported by the stage 7401.
[0328] Note that although the lighting device in which the
light-emitting portion is supported by the stage is described as an
example here, a housing provided with a light-emitting portion can
be fixed on a ceiling or suspended from a ceiling. Since the
light-emitting surface can be curved, the light-emitting surface is
curved to have a concave shape, whereby a particular region can be
brightly illuminated, or the light-emitting surface is curved to
have a convex shape, whereby a whole room can be brightly
illuminated.
[0329] FIGS. 33A1, 33A2, 33B, 33C, 33D, 33E, 33F, 33G, 33H, and 331
each illustrate an example of a portable information terminal
including a display portion 7001 having flexibility.
[0330] The display portion 7001 is manufactured using the display
device, the input/output device, or the like of one embodiment of
the present invention. For example, a display device, or an
input/output device that can be bent with a radius of curvature of
greater than or equal to 0.01 mm and less than or equal to 150 mm
can be used. The display portion 7001 may include a touch sensor so
that the portable information terminal can be operated by touching
the display portion 7001 with a finger or the like. One embodiment
of the present invention makes it possible to provide a highly
reliable electronic device including a display portion having
flexibility.
[0331] FIGS. 33A1 and 33A2 are a perspective view and a side view
illustrating an example of the portable information terminal,
respectively. A portable information terminal 7500 includes a
housing 7501, the display portion 7001, a display portion tab 7502,
operation buttons 7503, or the like.
[0332] The portable information terminal 7500 includes a rolled
flexible display portion 7001 in the housing 7501.
[0333] The portable information terminal 7500 can receive a video
signal with a control portion incorporated therein and can display
the received video on the display portion 7001. The portable
information terminal 7500 incorporates a battery. A terminal
portion for connecting a connector may be included in the housing
7501 so that a video signal or power can be directly supplied from
the outside with a wiring.
[0334] By pressing the operation buttons 7503, power ON/OFF,
switching of displayed videos, and the like can be performed.
Although FIGS. 33A1, 33A2, and 33B illustrate an example where the
operation buttons 7503 are positioned on a side surface of the
portable information terminal 7500, one embodiment of the present
invention is not limited thereto. The operation buttons 7503 may be
placed on a display surface (a front surface) or a rear surface of
the portable information terminal 7500.
[0335] FIG. 33B illustrates the portable information terminal 7500
in a state where the display portion 7001 is pulled out with the
display portion tab 7502. Videos can be displayed on the display
portion 7001 in this state. In addition, the portable information
terminal 7500 may perform different displays in the state where
part of the display portion 7001 is rolled as shown in FIG. 33A1
and in the state where the display portion 7001 is pulled out with
the display portion tab 7502 as shown in FIG. 33B. For example, in
the state shown in FIG. 33A1, the rolled portion of the display
portion 7001 is put in a non-display state, which results in a
reduction in power consumption of the portable information terminal
7500.
[0336] A reinforcement frame may be provided for a side portion of
the display portion 7001 so that the display portion 7001 has a
flat display surface when pulled out.
[0337] Note that in addition to this structure, a speaker may be
provided for the housing so that sound is output with the use of an
audio signal received together with a video signal.
[0338] FIGS. 33C to 33E illustrate an example of a foldable
portable information terminal FIG. 33C illustrates a portable
information terminal 7600 that is opened. FIG. 33D illustrates the
portable information terminal 7600 that is being opened or being
folded. FIG. 33E illustrates the portable information terminal 7600
that is folded. The portable information terminal 7600 is highly
portable when folded, and is highly browsable when opened because
of a seamless large display area.
[0339] A display portion 7001 is supported by three housings 7601
joined together by hinges 7602. By folding the portable information
terminal 7600 at a connection portion between two housings 7601
with the hinges 7602, the portable information terminal 7600 can be
reversibly changed in shape from an opened state to a folded
state.
[0340] FIGS. 33F and 33G illustrate an example of a foldable
portable information terminal FIG. 33F illustrates a portable
information terminal 7650 that is folded so that the display
portion 7001 is on the inside. FIG. 33G illustrates the portable
information terminal 7650 that is folded so that the display
portion 7001 is on the outside. The portable information terminal
7650 includes the display portion 7001 and a non-display portion
7651. When the portable information terminal 7650 is not used, the
portable information terminal 7650 is folded so that the display
portion 7001 is on the inside, whereby the display portion 7001 can
be prevented from being contaminated or damaged.
[0341] FIG. 33H illustrates an example of a flexible portable
information terminal. A portable information terminal 7700 includes
a housing 7701 and the display portion 7001. The portable
information terminal 7700 may include buttons 7703a and 7703b which
serve as input means, speakers 7704a and 7704b which serve as sound
output means, an external connection port 7705, a microphone 7706,
or the like. A flexible battery 7709 can be included in the
portable information terminal 7700. The battery 7709 may be
arranged to overlap with the display portion 7001, for example.
[0342] The housing 7701, the display portion 7001, the battery 7709
are flexible. Thus, it is easy to curve the portable information
terminal 7700 into a desired shape or to twist the portable
information terminal 7700. For example, the portable information
terminal 7700 can be curved so that the display portion 7001 is on
the inside or on the outside. The portable information terminal
7700 can be used in a rolled state. Since the housing 7701 and the
display portion 7001 can be transformed freely in this manner, the
portable information terminal 7700 is less likely to be broken even
when the portable information terminal 7700 falls down or external
stress is applied to the portable information terminal 7700.
[0343] The portable information terminal 7700 can be used
conveniently in various situations because the portable information
terminal 7700 is lightweight. For example, the portable information
terminal 7700 can be used in the state where the upper portion of
the housing 7701 is suspended by a clip or the like, or in the
state where the housing 7701 is fixed to a wall by magnets or the
like.
[0344] FIG. 33I illustrates an example of a wrist-watch-type
portable information terminal. The portable information terminal
7800 includes a band 7801, the display portion 7001, an
input-output terminal 7802, operation buttons 7803, and the like.
The band 7801 has a function of a housing. A flexible battery 7805
can be included in the portable information terminal 7800. The
battery 7805 may overlap with the display portion 7001 and the band
7801, for example.
[0345] The band 7801, the display portion 7001, and the battery
7805 have flexibility. Thus, the portable information terminal 7800
can be easily curved to have a desired shape.
[0346] With the operation buttons 7803, a variety of functions such
as time setting, ON/OFF of the power, ON/OFF of wireless
communication, setting and cancellation of silent mode, and setting
and cancellation of power saving mode can be performed. For
example, the functions of the operation buttons 7803 can be set
freely by the operating system incorporated in the portable
information terminal 7800.
[0347] By touching an icon 7804 displayed on the display portion
7001 with a finger or the like, application can be started.
[0348] The portable information terminal 7800 can employ near field
communication conformable to a communication standard. In that
case, for example, mutual communication between the portable
information terminal and a headset capable of wireless
communication can be performed, and thus hands-free calling is
possible.
[0349] The portable information terminal 7800 may include the
input-output terminal 7802. In the case where the input-output
terminal 7802 is included in the portable information terminal
7800, data can be directly transmitted to and received from another
information terminal via a connector. Charging through the
input-output terminal 7802 is also possible. Note that charging of
the portable information terminal described as an example in this
embodiment can be performed by contactless power transmission
without using the input-output terminal.
[0350] FIG. 34A is an external view of an automobile 9700. FIG. 34B
illustrates a driver's seat of the automobile 9700. The automobile
9700 includes a car body 9701, wheels 9702, a dashboard 9703,
lights 9704, and the like. The display device or the input/output
device of one embodiment of the present invention can be used in a
display portion or the like of the automobile 9700. For example,
the display device or the input/output device of one embodiment of
the present invention can be used in display portions 9710 to 9715
illustrated in FIG. 34B.
[0351] The display portion 9710 and the display portion 9711 are
display devices or input/output devices provided in an automobile
windshield. The display device or input/output device of one
embodiment of the present invention can be a see-through display
device or input/output device, through which the opposite side can
be seen, by using a light-transmitting conductive material for its
electrodes. Such a see-through display device or input/output
device does not hinder driver's vision during the driving of the
automobile 9700. Therefore, the display device or input/output
device of one embodiment of the present invention can be provided
in the windshield of the automobile 9700. Note that in the case
where a transistor or the like for driving the display device or
input/output device is provided in the display device or
input/output device, a transistor having light-transmitting
properties, such as an organic transistor using an organic
semiconductor material or a transistor using an oxide
semiconductor, is preferably used.
[0352] The display portion 9712 is a display device or an input
device provided on a pillar portion. For example, an image taken by
an imaging unit provided in the car body is displayed on the
display portion 9712, whereby the view hindered by the pillar
portion can be compensated. The display portion 9713 is a display
device or an input device provided on the dashboard. For example,
an image taken by an imaging unit provided in the car body is
displayed on the display portion 9713, whereby the view hindered by
the dashboard can be compensated. That is, by displaying an image
taken by an imaging unit provided on the outside of the automobile,
blind areas can be eliminated and safety can be increased.
Displaying an image to compensate for the area which a driver
cannot see makes it possible for the driver to confirm safety
easily and comfortably.
[0353] FIG. 34C illustrates the inside of a car in which a bench
seat is used as a driver seat and a front passenger seat. A display
portion 9721 is a display device or input/output device provided in
a door portion. For example, the display portion 9721 can
compensate for the view hindered by the door portion by showing an
image taken by an imaging unit provided on the car body. A display
portion 9722 is a display device or input/output device provided in
a steering wheel. A display portion 9723 is a display device or
input/output device provided in the middle of a seating face of the
bench seat. Note that the display device or input/output device can
be used as a seat heater by providing the display device or
input/output device on the seating face or backrest and by using
heat generated by the display device or input/output device as a
heat source.
[0354] The display portion 9714, the display portion 9715, and the
display portion 9722 can provide a variety of kinds of information
such as navigation data, a speedometer, a tachometer, a mileage, a
fuel meter, a gearshift indicator, and air-condition setting. The
content, layout, or the like of the display on the display portions
can be changed freely by a user as appropriate. The information
listed above can also be displayed on the display portions 9710 to
9713, 9721, and 9723. The display portions 9710 to 9715 and 9721 to
9723 can also be used as lighting devices. The display portions
9710 to 9715 and 9721 to 9723 can also be used as heating
devices.
[0355] The display portions each including the display device or
input/output device of one embodiment of the present invention can
be flat, in which case the display device or input/output device of
one embodiment of the present invention does not necessarily have a
curved surface or flexibility.
[0356] FIG. 34D illustrates a portable game machine including a
housing 901, a housing 902, a display portion 903, a display
portion 904, a microphone 905, a speaker 906, an operation button
907, a stylus 908, and the like.
[0357] The portable game machine illustrated in FIG. 34D includes
two display portions 903 and 904. Note that the number of display
portions of an electronic device of one embodiment of the present
invention is not limited to two and can be one or three or more as
long as at least one display portion includes the display device or
input/output device of one embodiment of the present invention.
[0358] FIG. 34E illustrates a laptop personal computer, which
includes a housing 921, a display portion 922, a keyboard 923, a
pointing device 924, and the like.
[0359] The display device or input/output device of one embodiment
of the present invention can be used in the display portion
922.
[0360] FIG. 35A is an external view of a camera 8000. The camera
8000 includes a housing 8001, a display portion 8002, an operation
button 8003, a shutter button 8004, and a connection portion 8005.
A lens 8006 can be put on the camera 8000.
[0361] The connection portion 8005 includes an electrode to connect
with a finder 8100, which is described below, a stroboscope, or the
like.
[0362] Although the lens 8006 of the camera 8000 here is detachable
from the housing 8001 for replacement, the lens 8006 may be
included in a housing.
[0363] Images can be taken at a touch of the shutter button 8004.
In addition, images can be taken at a touch of the display portion
8002 which serves as a touch panel.
[0364] The display device or input/output device of one embodiment
of the present invention can be used in the display portion
8002.
[0365] FIG. 35B shows the camera 8000 with the finder 8100
connected.
[0366] The finder 8100 includes a housing 8101, a display portion
8102, and a button 8103.
[0367] The housing 8101 includes a connection portion for the
connection portion 8005 of the camera 8000, and the finder 8100 can
be connected to the camera 8000. The connection portion includes an
electrode, and an image or the like received from the camera 8000
through the electrode can be displayed on the display portion
8102.
[0368] The button 8103 has a function of a power button, and the
display portion 8102 can be turned on and off with the button
8103.
[0369] The display device or input/output device of one embodiment
of the present invention can be used in the display portion
8102.
[0370] Although the camera 8000 and the finder 8100 are separate
and detachable electronic devices in FIGS. 35A and 35B, the housing
8001 of the camera 8000 may include a finder having the display
device or input/output device of one embodiment of the present
invention.
[0371] FIG. 35C illustrates an external view of a head-mounted
display 8200.
[0372] The head-mounted display 8200 includes a mounting portion
8201, a lens 8202, a main body 8203, a display portion 8204, a
cable 8205, and the like. The mounting portion 8201 includes a
battery 8206.
[0373] Power is supplied from the battery 8206 to the main body
8203 through the cable 8205. The main body 8203 includes a wireless
receiver or the like to receive video data, such as image data, and
display it on the display portion 8204. In addition, the movement
of the eyeball and the eyelid of a user can be captured by a camera
in the main body 8203 and then coordinates of the points the user
looks at can be calculated based on the captured data to utilize
the eye point of the user as an input means.
[0374] The mounting portion 8201 may include a plurality of
electrodes that are to be in contact with the user. The main body
8203 may be configured to sense current flowing through the
electrodes with the movement of the user's eyeball to recognize the
location of his/her eye. The main body 8203 may be configured to
sense current flowing through the electrodes to monitor the user's
pulse. The mounting portion 8201 may include sensors, such as a
temperature sensor, a pressure sensor, or an acceleration sensor
and display the user's biological information on the display
portion 8204. The main body 8203 may be configured to sense the
movement of the user's head to move an image displayed on the
display portion 8204 in synchronization with the movement of the
user's head.
[0375] The display device or input/output device of one embodiment
of the present invention can be used in the display portion
8204.
[0376] At least part of this embodiment can be implemented in
combination with any of the embodiments described in this
specification as appropriate.
[0377] This application is based on Japanese Patent Application
serial no. 2014-212646 filed with Japan Patent Office on Oct. 17,
2014, the entire contents of which are hereby incorporated by
reference.
* * * * *