TWI761320B - Display device and electronic device - Google Patents

Abstract

The present invention provides a display device with good visibility. The present invention is a display device, comprising a first substrate, a second substrate, a first display element, a second display element, and an input device, wherein the first substrate includes a part of the first display element and the second display element, and the second substrate includes The input device, the first display element and the second display element are arranged between the first surface of the first substrate and the first surface of the second substrate, the first display element has the function of reflecting visible light, and the second display element has the function of emitting visible light and an anti-reflection layer is arranged on the second surface facing the first surface of the second substrate.

Description

Display device and electronic device

The present invention relates to an object, method or method of manufacture. Furthermore, the present invention relates to a process, machine, manufacture or composition of matter. In particular, one embodiment of the present invention relates to a semiconductor device, a light-emitting device, a display device, an electronic device, a lighting apparatus, a driving method thereof, or a manufacturing method thereof. In particular, one embodiment of the present invention relates to a display device (display panel) capable of displaying on a curved surface. Furthermore, the present invention relates to an electronic device, a light-emitting device, a lighting apparatus including a display device capable of displaying on a curved surface, or a manufacturing method thereof.

Note that, in this specification and the like, a semiconductor device refers to all devices that can operate by utilizing semiconductor characteristics. A transistor, a semiconductor circuit, an arithmetic device, a memory device, and the like are all one embodiment of a semiconductor device. In addition, light-emitting devices, display devices, electronic devices, lighting equipment, and electronic devices may include semiconductor devices.

In recent years, electronic devices such as smart phones and tablet terminals have become widespread, and opportunities for information and communication outdoors are increasing. In addition, in the field of display devices included in electronic devices, research and development of low-power consumption technologies that can operate for a long time using batteries with limited capacity have been conducted. For example, Patent Document 1 discloses a low-power-consumption liquid crystal display device that maintains a video signal for a long time by using a transistor including an oxide semiconductor with a small off-state current for a pixel.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2011-141522

As a display device included in an electronic device, a transmissive liquid crystal element or a self-luminous organic EL element using a backlight as a light source is often used. The indoor visibility of such a display element is good, but under strong light such as outdoors on a sunny day, the external light reflected by the display surface is strongly reflected, so that the visibility of light (display) emitted from the inside of the display device decreases.

Therefore, it is preferable to use a reflective display element utilizing external light reflection under strong light. For example, in a display device using a reflective liquid crystal element, the stronger the external light, the higher the visibility. However, since glass substrates or resin substrates with a reflectivity of several percent are used in the display surface of the display device, the influence of external light reflection on the display cannot be solved.

In addition, the visibility of the reflective display element is insufficient in a room where external light is weak.

Accordingly, one of the objects of an embodiment of the present invention is to provide a display device having high visibility even under strong light. Further, one of the objects of one embodiment of the present invention is to provide a display device including a display element having a function of emitting visible light and a display element having a function of reflecting visible light. In addition, one of the objectives of an embodiment of the present invention is to provide a display system with low power consumption. Furthermore, one of the objects of an embodiment of the present invention is to provide a novel display device. Furthermore, one of the objects of an embodiment of the present invention is to provide a novel electronic device.

Note that the description of these purposes does not prevent the existence of other purposes. An embodiment of the present invention need not achieve all of the above objectives. In addition, objects other than the above-mentioned objects are obvious from the description in the specification and the like, and the objects other than the above-mentioned objects can be derived from the description in the specification and the like.

One embodiment of the present invention relates to a display device having a function of emitting visible light, a display device having a function of reflecting visible light, or a display device having a function of emitting visible light and a function of reflecting visible light. In addition, one embodiment of the present invention relates to an electronic device including the above-described display device. A detailed description will be given below.

One embodiment of the present invention is a display device, comprising: a first substrate; a second substrate; a first display element; a second display element; and an input device, wherein the first substrate includes a part of the first display element and a second The display element, the second substrate includes an input device, the first display element and the second display element are arranged between the first surface of the first substrate and the first surface of the second substrate, the first display element has the function of reflecting visible light, and the first display element has the function of reflecting visible light. The two display elements have the function of emitting visible light, and an anti-reflection layer is provided on the second surface opposite to the first surface of the second substrate.

In the above manner, preferably, the first display element and the second display element are arranged in the same pixel unit.

In the above manner, it is preferable to further include a driving circuit, and the driving circuit has the function of driving the first display element, the second display element and the input device.

In the above manner, preferably, the first display element has a liquid crystal material, the second display element has an EL material, and the liquid crystal material has a dichroic dye.

In the above-mentioned form, it is preferable that the antireflection layer has a convex portion.

In the above manner, preferably, one or more selected from the group consisting of a light diffusing plate, a polarizing plate and a color film is included between the first display element and the input device.

In the above manner, preferably, the first display element and the second display element are respectively electrically connected to a transistor whose semiconductor layer forming the channel includes a metal oxide.

Another embodiment of the present invention is an electronic device including: the display device of any one of the above; a housing; and a hinge portion, wherein the housing and the hinge portion include an area for accommodating the display device.

In addition, in this specification, a display device is sometimes included in a module in which a display device (display portion) is mounted with a connector such as FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) ) module; a module in which a printed wiring board is provided at the end of the TCP; and an IC (integrated circuit) is directly mounted on the substrate on which the display element is formed by COG (Chip On Glass: crystal grain glass bonding) method 's module.

By utilizing one embodiment of the present invention, it is possible to provide a display device with high visibility even under strong light. Furthermore, a display device including a display element having a function of emitting visible light and a display element having a function of reflecting visible light can be provided. Furthermore, a display system with low power consumption can be provided. Furthermore, a novel display device can be provided. Furthermore, a novel electronic device can be provided.

Note that the description of these effects does not prevent the existence of other effects. Furthermore, it is not necessary for an embodiment of the present invention to have all of the above-described effects. Effects other than the above-mentioned effects are obvious from the descriptions in the specification, drawings, claims, etc., and effects other than the above-mentioned effects can be extracted from the descriptions.

10‧‧‧Display device

11‧‧‧Substrate

12‧‧‧Substrate

13‧‧‧Anti-reflection layer

13a‧‧‧Dielectric layer

13b‧‧‧Dielectric layer

13c‧‧‧Anti-glare pattern

13d‧‧‧Film

Floor 20‧‧‧

21‧‧‧Component layer

21a‧‧‧FET layer

21b‧‧‧LC layer

21b_LC‧‧‧LC layer

21c‧‧‧OLED layer

22‧‧‧Component layer

23‧‧‧Light Diffuser

25‧‧‧Input device

25a‧‧‧Input device

25b‧‧‧Polarizer

26‧‧‧Adhesive layer

26a‧‧‧Adhesive layer

30‧‧‧Drive circuit

30a‧‧‧Drive circuit

30b‧‧‧Drive circuit

31‧‧‧FPC

32‧‧‧FPC

33a‧‧‧Wiring

33b‧‧‧Wiring

33c‧‧‧Wiring

33d‧‧‧Wiring

35‧‧‧Liquid crystal element

36‧‧‧Pixel circuit

40‧‧‧Pixel Array

45‧‧‧Pixel Unit

46‧‧‧pixels

46B‧‧‧Display Components

46G‧‧‧Display Components

46R‧‧‧Display Components

47‧‧‧Pixels

47B‧‧‧Display Components

47G‧‧‧Display Components

47R‧‧‧Display Components

55‧‧‧Light

101‧‧‧ Area

102‧‧‧Area

106‧‧‧Insulating film

117‧‧‧Insulating layer

121‧‧‧Insulating layer

131‧‧‧Color Layer

132‧‧‧Light shielding layer

133a‧‧‧Alignment Film

133b‧‧‧Alignment Film

134‧‧‧Color Layers

141‧‧‧Adhesive layer

142‧‧‧Adhesive layer

161‧‧‧Substrate

161a‧‧‧Substrate

161b‧‧‧Substrate

162‧‧‧Peeling layer

162a‧‧‧Peel layer

162b‧‧‧Peeling layer

163‧‧‧Peeled layer

163a‧‧‧Peeled layer

163b‧‧‧Peeled layer

164‧‧‧Insulation

164a‧‧‧Insulation

165‧‧‧Opening

166‧‧‧Insulation

167‧‧‧Polarizer

168‧‧‧Substrate

169‧‧‧Adhesive layer

170‧‧‧Conductive layer

171‧‧‧Wiring

171a‧‧‧Conductive layer

171b‧‧‧Dark layer

172‧‧‧Wiring

172a‧‧‧Conductive layer

172b‧‧‧Dark layer

173‧‧‧Wiring

173a‧‧‧Conductive layer

173b‧‧‧Dark layer

174‧‧‧Wiring

174a‧‧‧Conductive layer

174b‧‧‧Conductive layer

176‧‧‧Adhesive layer

179‧‧‧Conductive layer

179a‧‧‧Conductive layer

179b‧‧‧Conductive layer

180‧‧‧Insulation

180a‧‧‧Insulation layer

181‧‧‧Light shielding layer

181a‧‧‧Light shielding layer

182‧‧‧Color Layers

182a‧‧‧Color layer

183‧‧‧Insulation

183a‧‧‧Insulating layer

184‧‧‧Adhesive layer

185‧‧‧Light Diffuser

186‧‧‧Adhesive layer

187‧‧‧Adhesive layer

191‧‧‧Conductive layer

192‧‧‧EL layer

193a‧‧‧Conductive layer

193b‧‧‧Conductive layer

201‧‧‧Transistor

204‧‧‧Connection

205‧‧‧Transistor

206‧‧‧Transistor

207‧‧‧Connection

211‧‧‧Insulating layer

212‧‧‧Insulating layer

213‧‧‧Insulating layer

214‧‧‧Insulating layer

215‧‧‧Insulation

216‧‧‧Insulating layer

217‧‧‧Insulating layer

220‧‧‧Insulating layer

221‧‧‧Conductive layer

222‧‧‧Conductive layer

223‧‧‧Conductive layer

224‧‧‧Conductive layer

231‧‧‧Semiconductor layer

242‧‧‧Connection layer

243‧‧‧Connector

251‧‧‧Opening

252‧‧‧Connection

300‧‧‧Display panel

311‧‧‧Electrode

311a‧‧‧Conductive layer

311b‧‧‧Conductive layer

312‧‧‧LCD

313‧‧‧Conductive layer

340‧‧‧Liquid crystal element

351‧‧‧Substrate

360‧‧‧Light-emitting element

360b‧‧‧Light-emitting element

360g‧‧‧Light-emitting element

360r‧‧‧Light-emitting element

360w‧‧‧Light-emitting element

361‧‧‧Substrate

362‧‧‧Display

364‧‧‧Circuit

365‧‧‧Wiring

366‧‧‧Touch Sensor

372‧‧‧FPC

373‧‧‧IC

400‧‧‧Display device

410‧‧‧pixels

451‧‧‧Opening

501B‧‧‧Insulating Film

560‧‧‧Substrate

571‧‧‧Insulating film

572‧‧‧Insulating film

575‧‧‧Proximity Sensor

576‧‧‧Opening

723‧‧‧Electrode

724a‧‧‧electrode

724b‧‧‧electrode

726‧‧‧Insulation

727‧‧‧Insulation

728‧‧‧Insulation

729‧‧‧Insulation

741‧‧‧Insulating layer

742‧‧‧Semiconductor layer

744a‧‧‧electrode

744b‧‧‧electrode

746‧‧‧Electrode

755‧‧‧Impurities

771‧‧‧Substrate

772‧‧‧Insulating layer

780‧‧‧LCD element

781‧‧‧Electrodes

782‧‧‧Electrodes

783‧‧‧Liquid crystal layer

785a‧‧‧Alignment Film

785b‧‧‧Alignment Film

810‧‧‧Transistor

811‧‧‧Transistor

820‧‧‧Transistor

821‧‧‧Transistor

825‧‧‧Transistor

826‧‧‧Transistor

830‧‧‧Transistor

831‧‧‧Transistor

840‧‧‧Transistor

841‧‧‧Transistor

842‧‧‧Transistor

843‧‧‧Transistor

844‧‧‧Transistor

845‧‧‧Transistor

845A‧‧‧Transistor

846‧‧‧Transistor

847‧‧‧Transistor

920‧‧‧Electronic devices

921a‧‧‧Enclosure

921b‧‧‧Enclosure

922‧‧‧Display

923‧‧‧Hinges

950‧‧‧Electronic devices

952a‧‧‧Enclosure

952b‧‧‧Enclosure

953‧‧‧Hinge

954‧‧‧Display

954a‧‧‧Protrusion

961‧‧‧ Area

962‧‧‧ Area

1800‧‧‧Portable Information Terminal

1801‧‧‧Enclosure

1802‧‧‧Enclosure

1803‧‧‧Display

1804‧‧‧Display

1805‧‧‧Hinge

1810‧‧‧Portable Information Terminal

1811‧‧‧Enclosure

1812‧‧‧Display

1813‧‧‧Operation buttons

1814‧‧‧External port

1815‧‧‧Speaker

1816‧‧‧Microphone

1817‧‧‧Camera

1820‧‧‧Camera

1821‧‧‧Enclosure

1822‧‧‧Display

1823‧‧‧Operation buttons

1824‧‧‧Shutter button

1826‧‧‧Lens

1830‧‧‧TV

1831‧‧‧Display

1832‧‧‧Enclosure

1833‧‧‧Speakers

1834‧‧‧Remote control

1840‧‧‧Digital signage

1841‧‧‧Display

1842‧‧‧Pillars

1850‧‧‧PC

1851‧‧‧Display

1852‧‧‧Enclosure

1853‧‧‧Touchpad

1854‧‧‧Ports

1855‧‧‧Enter key

6000‧‧‧Display Module

6001‧‧‧Cover

6002‧‧‧Lower cover

6005‧‧‧FPC

6006‧‧‧Display Panel

6009‧‧‧Frame

6010‧‧‧Printed circuit board

6011‧‧‧Battery

6015‧‧‧Light-emitting part

6016‧‧‧Light Receiver

6017a‧‧‧Light guide

6017b‧‧‧Light guide

6018‧‧‧Light

In the drawings: FIGS. 1A and 1B are diagrams illustrating a display device; FIGS. 2A to 2F are diagrams illustrating an anti-reflection layer; FIG. 3 is a diagram illustrating a display device; FIG. 4 is a diagram illustrating the structure of a touch sensor 5A and 5B are diagrams illustrating the structure of the touch sensor; FIGS. 6A to 6D are diagrams illustrating connection examples of the driving circuit and the FPC; 8A to 8E are diagrams illustrating a method of manufacturing a display device; FIGS. 9A to 9D are diagrams illustrating a method of manufacturing a display device; FIGS. 10A to 10C are diagrams illustrating a method of manufacturing a display device 11 is a diagram illustrating the manufacturing method of the display device; FIG. 12A to FIG. 12E are diagrams illustrating the manufacturing method of the display device; FIG. 13A to FIG. 13E are diagrams illustrating the manufacturing method of the display device; 15A to 15C are diagrams illustrating a method of manufacturing a display device; FIG. 16 is a diagram illustrating a pixel unit; FIGS. 17A to 17C are diagrams illustrating a pixel unit; 18B2 is a diagram illustrating a circuit of the display device and a plan view of a pixel; FIG. 19 is a diagram illustrating a circuit of the display device; FIGS. 20A and 20B are a diagram illustrating the circuit of the display device and a plan view of the pixel; FIG. 22 is a diagram illustrating the structure of a display device; FIG. 23 is a conceptual diagram illustrating the structure of a metal oxide; FIG. 24 is a diagram illustrating the measurement result of the XRD spectrum of the sample; 25C to 25L are diagrams illustrating electron diffraction patterns; FIGS. 26A to 26C are diagrams illustrating EDX surface analysis images of the samples; FIGS. 27A and 27B are diagrams illustrating the operation of the liquid crystal element; , Figure 28A2, Figure 28B1, Figure 28B2, Figure 28C1 and Figure 28C2 are diagrams illustrating transistors; Figures 29A1, 29A2, Figure 29B1, Figure 29B2, Figure 29C1 and Figure 29C2 are diagrams illustrating transistors; 30A2, 30A3, 30B1, and 30B2 are diagrams illustrating transistors; FIGS. 31A1, 31A2, 31B1, and 31B2 are diagrams illustrating transistors; Figures 32C1 and 32C2 are diagrams illustrating transistors; Figures 33A1, 33A2, 33B1, 33B2, 33C1, and 33C2 are diagrams illustrating transistors; Figures 34A1 and 34A2 are diagrams illustrating transistors; Figure 35A 35B is a diagram illustrating a structural example of a display module; FIGS. 36A to 36D are diagrams illustrating electronic devices; FIGS. 37A to 37C are diagrams illustrating electronic devices; FIG. 38 is a diagram illustrating electronic devices; 39B is a diagram illustrating an electronic device; and FIGS. 40A and 40B are diagrams illustrating an electronic device.

Embodiments are described in detail with reference to the drawings. Note that the present invention is not limited to the following description, and it can be easily understood by those skilled in the art that the mode and details thereof can be changed in various ways without departing from the spirit and scope of the present invention. form. Therefore, the present invention should not be construed as being limited only to the contents described in the embodiments shown below.

Note that in the structure of the invention described below, the same reference numerals are commonly used in different drawings to denote the same parts or parts having the same function, and repeated description is omitted. In addition, the same hatching is sometimes used when denoting parts having the same function without particularly attaching reference symbols.

Note that, in each of the drawings described in this specification, the size of each component, the thickness of layers, and the region are sometimes exaggerated for clarity. Therefore, the present invention is not limited to the dimensions in the drawings.

The ordinal numbers such as "first" and "second" used in this specification and the like are appended to avoid confusion of components, and are not intended to be limited in terms of numbers.

Embodiment 1

In this embodiment, a display device according to an embodiment of the present invention will be described with reference to FIGS. 1A to 7C .

<1-1. Configuration Example 1 of Display Device>

A display device according to an embodiment of the present invention includes a first substrate, a second substrate, a first display element, a second display element, an input device, and a driving circuit.

The first display element has a function of reflecting visible light, and the second display element has a function of emitting visible light. Therefore, for example, by operating the first display element under strong light and operating the second display element under weak light, it is possible to perform high-visibility display with low power consumption.

The first display element, the second display element and the input device are arranged between the first surface of the first substrate and the first surface of the second substrate. An anti-reflection layer is provided on the second surface of the second substrate facing the first surface. Accordingly, even under strong light, reflection of external light on the display surface can be sufficiently suppressed, and visibility can be further improved.

FIG. 1A is a diagram illustrating a display device according to an embodiment of the present invention. The display device 10 shown in FIG. 1A includes a first substrate 11 , a second substrate 12 , a layer 20 , a driving circuit 30 , an FPC 31 and an FPC 32 .

As the first substrate 11 and the second substrate 12 , for example, glass substrates can be used. Alternatively, a flexible resin substrate may be used. Further, in the display device 10 , the second substrate 12 side is the display side (viewing side), and thus a material having light transmittance is used as at least the second substrate 12 .

In addition, an antireflection layer 13 is provided on both of the first surface and the second surface of the second substrate 12 or on the second surface. The anti-reflection layer 13 may have, for example, the structure shown in FIGS. 2A to 2F .

FIG. 2A shows an example in which a light-transmitting dielectric layer 13 a is provided on the second surface of the second substrate 12 on the top surface of the display device 10 . When a plurality of dielectric layers having an appropriate thickness are provided as the dielectric layer 13a, reflected light can be suppressed by utilizing the interference effect of light. The reflectance of one surface of the glass substrate is about 4% to 5%. By providing the light-transmitting dielectric layer 13a on the second surface of the second substrate 12, the reflectance can be reduced to about 0.05% to 0.5%.

In addition, as shown in FIG. 2B , by further providing a light-transmitting dielectric layer 13 b on the first surface of the second substrate 12 , the reflectance on the back surface side of the glass substrate can be suppressed. At this time, the reflectance of the front and back surfaces of the second substrate 12 can be reduced to about 0.1% to 1.0%. Therefore, external light reflection can be suppressed, and the visibility of the display can be improved.

Alternatively, as shown in FIG. 2C , an anti-glare pattern 13 c formed of minute protrusions may be provided on the second surface of the second substrate 12 . By using the anti-glare pattern 13c, the reflected light can be scattered, whereby the display using the reflective display element can be easily seen. In addition, it may not be easily soiled by fingerprints or the like. In addition, although FIG. 2C shows an example in which the second surface of the second substrate 12 is processed to form the anti-glare pattern 13c, as shown in FIG. 2D, the thin film 13d on which the anti-glare pattern is formed may also be attached to the second substrate 12 on the second side.

The fine protrusions provided in the anti-glare pattern 13c can be formed using, for example, silicon dioxide particles containing silicon and oxygen. The particle diameter of the silica particles is 1 μm or more and 100 μm or less, preferably 3 μm or more and 50 μm or less.

In addition, as shown in FIG. 2E, the anti-glare pattern 13c and the dielectric layer 13b may be combined. Furthermore, as shown in FIG. 2F , the thin film 13d on which the anti-glare pattern is formed and the dielectric layer 13b may be combined.

The description of FIG. 1A and FIG. 1B is performed again. A layer 20 is provided between the first substrate 11 and the second substrate 12 . Layer 20 will be described with reference to FIG. 1B . FIG. 1B corresponds to an enlarged cross-sectional view of the position X1 - X2 shown in FIG. 1A . The layer 20 includes an element layer 21 , an element layer 22 , an input device 25 and an adhesive layer 26 .

The element layer 21 includes an FET layer 21a, an LC layer 21b, an LC layer 21b_LC, and an OLED layer 21c. The FET layer 21a includes transistors and the like constituting a pixel circuit. The LC layer 21b includes a part of the first display element, and the LC layer 21b_LC includes the other part of the first display element. In addition, the first display element is composed of the LC layer 21b and the LC layer 21b_LC. The OLED layer 21c includes the second display element. The first display element and the second display element are electrically connected to the transistor included in the FET layer 21a.

As the first display element, for example, a reflective liquid crystal element can be used. As the second display element, for example, a light-emitting element can be used. Reflective liquid crystal elements can perform displays with low power consumption and high visibility even under clear sunlight. The light-emitting element can be displayed with high visibility under indoor light or outdoors on a cloudy day.

The reflective liquid crystal element is preferably driven in a guest-host liquid crystal mode. By using the guest-host liquid crystal mode, it is possible to provide a reflective display element without using a polarizing plate. Since a polarizing plate is not used, bright display of the liquid crystal device is realized. Note that the reflective liquid crystal element according to one embodiment of the present invention is not limited to the guest-host liquid crystal mode, and a TN (Twisted Nematic) mode, an OCB (Optically Compensated Birefringence: optically compensated birefringence) mode, a vertical alignment ( VA) mode and other driving methods.

By using the structures shown in FIGS. 1A and 1B , it is possible to provide a display device capable of high-visibility display regardless of the intensity of external light. In particular, the display device has good visibility under strong light and can operate with low power consumption.

In the display device 10 shown in FIGS. 1A and 1B , the antireflection layer 13 , the input device 25 , and the element layer 22 are provided on the second substrate 12 side. By adopting this structure, the second substrate 12 can be formed through a simple process. Therefore, the manufacturing cost can be reduced. In addition, by making the second substrate 12 a thin film substrate (for example, the thickness is less than 0.7 mm, preferably 0.1 mm or more and 0.5 mm or less, more preferably 0.1 mm or more and 0.3 mm or less), the second substrate can be reduced 12 The thinning process is typically a polishing process. By subtracting the polishing process, the yield of the display device 10 can be improved.

As the input device 25, for example, an electrostatic capacitance type touch sensor can be used. The input device 25 overlaps the display unit, and has a function of converting the user's action of touching the display unit into an electrical signal and outputting it.

The input device 25 may be provided on the first surface of the second substrate 12 . Alternatively, the input device 25 may be provided on the above-mentioned dielectric layer 13b. In the electrostatic capacitance type touch sensor, a light-transmitting conductive film can be used as wiring and electrodes, but metal mesh is preferably used. The wire mesh has low resistance, and thus can be used in large-scale display devices. In addition, in general, metal is a material with high reflectance, but can be darkened by oxidation treatment. Thus, even when viewed from the side of the second substrate, it is possible to suppress a decrease in visibility caused by reflection of external light.

FIG. 4 is a diagram showing an example of an electrostatic capacitance type touch sensor provided on a substrate, and a part of the touch sensor is shown enlarged. 5A is a top view of a touch sensor including a proximity sensor. FIG. 5B is a cross-sectional view taken along line X3-X4 of FIG. 5A . The substrate on which the touch sensor is disposed may be the second substrate 12 shown in FIG. 1A and FIG. 1B and the like.

The insulating film 501B shown in FIG. 5B corresponds to the adhesive layer 26 shown in FIGS. 1A and 1B and the like. Further, the insulating film 572 includes a region sandwiched between the insulating film 501B and the proximity sensor 575 .

As the proximity sensor 575 , a detection element that detects changes in electrostatic capacitance, illuminance, magnetic force, radio waves, pressure, etc. caused by an approaching object and supplies a signal based on the detected physical quantity can be used.

For example, a conductive film, a photoelectric conversion element, a magnetic detection element, a piezoelectric element, a resonator, or the like can be used as the detection element.

For example, as the proximity sensor 575, a detection circuit having a function of supplying a signal that varies based on an electrostatic capacitance parasitic in the conductive film may be used. A control signal may be supplied to the first electrode, and a potential or current of the second electrode that changes based on the supplied control signal and electrostatic capacitance may be detected and supplied as a detection signal. Thereby, by utilizing the change in electrostatic capacitance, it is possible to detect a finger or the like approaching the conductive film in the atmosphere.

For example, the first electrode C1(g) and the second electrode C2(h) may be used for the proximity sensor 575 (see FIGS. 4 and 5A ). The second electrode C2(h) has a portion that does not overlap with the first electrode C1(g). g and h are natural numbers of 1 or more.

Specifically, the first electrode C1(g), which is electrically connected to the control line CL(g) extending in the row direction (the direction of the arrow indicated by R in the drawing), and the first electrode C1(g) extending in the row direction cross The second electrode C2(h) to which the signal line ML(h) is electrically connected in the column direction of (the direction of the arrow indicated by C in the drawing) is used for the proximity sensor 575 .

For example, a conductive film having a light-transmitting region in a region overlapping with a pixel may be used for the first electrode C1 (g) or the second electrode C2 (h).

For example, a mesh-shaped conductive film having openings 576 in regions overlapping with the pixels can be used for the first electrode C1 (g) or the second electrode C2 (h).

The control line CL(g) includes the wiring BR(g, h). The control line CL(g) intersects the signal line ML(h) in the wiring BR(g, h) (see FIG. 5B ).

For example, a laminated film can be used for the first electrode C1(g), the second electrode C2(h), the control line CL(g), the signal line ML(h), and the wiring BR(g,h). For example, a laminated film in which the conductive film CL(g)A and the dark film CL(g)B are laminated such that the conductive film CL(g)A is sandwiched between the dark film CL(g)B and the pixel can be used.

Here, it is preferable to use a film whose visible light reflectance is lower than that of the conductive film CL(g)A for the dark color film CL(g)B.

In addition, as the wiring BR(g, h), a laminated film in which the conductive film BR(g, h)A and the dark film BR(g, h)B are laminated can be used. It is preferable to use a film whose visible light reflectance is lower than that of the conductive film BR(g,h)A for the dark film BR(g,h)B.

Thereby, the reflection of visible light by the first electrode C1(g), the second electrode C2(h), the control line CL(g), the signal line ML(h), and the wiring BR(g, h) can be reduced. As a result, the display on the display unit can be emphasized, whereby favorable display can be performed.

For example, the materials shown below can be used for the conductive film CL(g)A and the conductive film BR(g, h)A.

In addition, a film containing copper oxide, a film containing copper chloride, tellurium chloride, or nickel oxide, or the like can be used for the dark film CL(g)B and the dark film BR(g, h)B. In addition, the dark film CL(g)B and the dark film BR(g, h)B can also use metal particles such as Ag particles, Ag fibers, and Cu particles, carbon nanotubes (CNT), graphene and other nanocarbon particles or PEDOT, polyaniline, polypyrrole and other conductive polymers are formed.

In addition, the proximity sensor 575 includes an insulating film 571 between the wiring BR(g, h) and the signal line ML(h). Thereby, short-circuiting between the wiring BR(g, h) and the signal line ML(h) can be prevented.

The description of FIG. 1A and FIG. 1B is performed again. The input device 25 has a structure overlapping the first display element and the second display element. The input device 25 can be manufactured by a different process than the transistor, the first display element, and the second display element, thus improving the yield of each component.

The driving circuit 30 may have a function as a source driver for supplying image data to the first display element and the second display element, and may also have a function of controlling the input device 25 . The driver circuit 30 can be provided by, for example, mounting an IC chip formed using a silicon wafer. Alternatively, the driving circuit 30 may be formed using a transistor provided on the first substrate 11 .

1A and FIG. 1B illustrate a method of mounting a bare chip as the driver circuit 30 by using COG, it may be mounted by TCP or COF (Chip on Film).

The drive circuit 30 is electrically connected to a circuit or the like for supplying image data through the FPC 31 . In addition, the input device 25 is electrically connected to the driving circuit 30 through the FPC 32 .

6A to 6D are diagrams illustrating the electrical connection of the drive circuit 30 , the FPC 31 , and the FPC 32 .

FIG. 6A shows an example in which the driver circuit 30 has a function as a source driver for supplying video data to the first display element and the second display element and a function of controlling the input device 25. As shown in FIG. At this time, the drive circuit 30 can be electrically connected to the FPC 31 through the wiring 33a. In addition, the drive circuit 30 may be electrically connected to the FPC 32 through the wiring 33b.

FIG. 6B shows an example in which the drive circuit 30 is divided into two. Here, the driver circuit 30a has a function as a source driver for supplying image data to the first display element and the second display element. The drive circuit 30 b has a function of controlling the input device 25 . At this time, the drive circuit 30a can be electrically connected to the FPC 31 through the wiring 33a. The drive circuit 30b can be electrically connected to the FPC 32 through the wiring 33b.

In addition, as shown in FIG. 6C , the driving circuit 30a and the driving circuit 30b may be electrically connected to each other by the wiring 33c. In addition, as shown in FIG. 6D, the FPC 31 and the FPC 32 may also be electrically connected to each other by the wiring 33d. By adopting this structure, wiring for supplying power supply voltage or signal can be reduced.

The description of FIG. 1A and FIG. 1B is performed again. As the transistor provided in the FET layer 21a, a transistor containing a metal oxide in a channel region (hereinafter referred to as an OS transistor) is preferably used. The off-state current of the OS transistor is extremely small, so it can maintain the potential written as image data for a long period of time. As a result, during a plurality of frame periods, the image display can be maintained without writing new image data, that is, so-called idling stop driving can be realized.

During the idling stop drive, the image data written in the pixels can be held for more than 2 frame periods. Accordingly, the rewriting frequency of the image data can be reduced, and the power consumption can be reduced.

Since the reflective liquid crystal element that can be used as the first display element does not require a backlight, the power consumption of the pixel portion is equal to the power consumption of the circuit operation. Therefore, it is particularly preferable to use idling stop driving for the pixel including the first display element, and in this case, the power consumption of the pixel portion can be reduced in proportion to the rewriting frequency.

An example of the above-described idling stop driving will be described with reference to FIGS. 7A to 7C .

FIG. 7A shows a circuit diagram of a pixel constituted by the liquid crystal element 35 and the pixel circuit 36 . FIG. 7A shows the transistor M1, the capacitive element Cs _LC , and the liquid crystal element LC connected to the signal line SL and the gate line GL.

7B is a timing chart showing the waveforms of the signals supplied to the signal line SL and the gate line GL, respectively, in the normal driving mode in which the idling stop driving is not performed. In the normal drive mode, it is possible to operate at the normal frame frequency (eg 60 Hz).

When T1, T2, and T3 denote the respective periods _of the consecutive frames of the above _- mentioned frame frequency, _a scanning signal is supplied to the gate line in each frame period, and the data D1 _of the signal line is written into the pixel. Work. _The above operation is performed regardless _of whether the same data _D1 or different data are written in the periods T1, T2 and _T3 .

7C is a timing chart showing the waveforms of the signals supplied to the signal line SL and the gate line GL, respectively, at the time of idling stop driving. In idle-stop driving, it is possible to operate at a low frame frequency (eg, 1 Hz).

In FIG. 7C , the frame period of the above-mentioned frame frequency is represented by T ₁ , wherein the data writing period is represented by _TW , and the data retention period is represented by T _RET . In the idling stop driving, a scan signal is supplied to the gate line during the period _TW , the data D1 _of the signal line is written into the pixel, and the gate line is fixed to a low level voltage during the period T _RET , so that the transistor M1 is non-conductive state to keep the written data _D1 in the pixel.

Here, when an OS transistor is used as the transistor M1, the data D1 can be held for _a long time due to the low off-state current of the OS transistor. Although FIGS. 7A to 7C show an example in which a liquid crystal element LC is used, it is also possible to perform idling stop driving in the same manner as described above when a light-emitting element such as an organic EL element is used.

In addition, in the circuit diagram shown in FIG. 7A, the liquid crystal element LC becomes the leakage path _of the data D1. Therefore, in order to properly perform idling stop driving, the resistivity of the liquid crystal element LC is preferably 1.0×10 ¹⁴ Ω. cm or more.

As the metal oxide used for the above-mentioned transistor, for example, CAC-OS (Cloud-Aligned Composite-Oxide Semiconductor), which will be described later, or the like can be used.

In particular, it is preferable to use an oxide semiconductor whose energy band gap is larger than that of silicon. By using a semiconductor material that has a larger band gap than silicon and a lower carrier density than silicon, the transistor's off-state current can be reduced.

In addition, since the above-mentioned transistor has a low off-state current, the charge stored in the capacitor by the transistor can be held for a long period of time. By using such a transistor for a pixel, the driving circuit can be stopped while maintaining the grayscale of the image displayed on each display area. As a result, an electronic device with extremely low power consumption can be realized.

In addition, a polycrystalline semiconductor can also be used as a semiconductor device such as a transistor used in the above-mentioned pixel or a circuit for driving the pixel. For example, polysilicon or the like is preferably used. Compared with monocrystalline silicon, polycrystalline silicon can be formed at low temperature and has higher field mobility and reliability than amorphous silicon. By using such a polycrystalline semiconductor for a pixel, the aperture ratio of the pixel can be increased. In addition, even if an extremely large number of pixels are included, the gate driver circuit and the source driver circuit can be formed on the same substrate as the pixels, and the number of components constituting the electronic device can be reduced.

By using the above structure, it is possible to provide a display device capable of high-visibility display regardless of the intensity of external light. In particular, the display device has the advantages of having good visibility even under strong light and being able to operate with low power consumption.

<1-2. Configuration Example 2 of Display Device>

One embodiment of the layer 20 provided between the first substrate 11 and the second substrate 12 is shown in the display device 10 shown in FIGS. 1A and 1B , but the present invention is not limited thereto. For example, the layer 20 may also adopt the structure shown in FIG. 3 .

FIG. 3 corresponds to an enlarged cross-sectional view of a position X1-X2 shown in FIG. 1A which is different from the enlarged view shown in FIG. 1B .

The layer 20 shown in FIG. 3 includes an element layer 21 , an element layer 22 , a light diffusion plate 23 , an input device 25 and adhesive layers 26 and 26 a. In addition, the structure of the layer 20 shown in FIG. 3 is different from the structure of the layer 20 shown in FIG. 1B in the structures of the light diffusing plate 23 , the input device 25 , and the adhesive layer 26 a . The other components are the same as those shown in FIG. 1B and exert the same effect.

The light diffusing plate 23 has a function of diffusing the light reflected by the reflective electrodes of the liquid crystal element. This function enables natural color development even in reflective liquid crystal elements. Also, white like white paper can be displayed.

The input device 25 shown in FIG. 3 includes an input device 25a and a polarizing plate 25b. The input device 25a can have the same structure as the input device 25 described above.

As the polarizing plate 25b, for example, a circular polarizing plate can be used. Display using reflected light can be performed by using a change in deflection angle by a circular polarizer and a liquid crystal.

Note that the position where the polarizing plate 25b is provided is not limited to the structure shown in FIG. 3 . For example, a configuration in which a polarizing plate 25b is provided between the input device 25a and the light diffusing plate 23 or between the light diffusing plate 23 and the element layer 22 may be employed.

The adhesive layer 26a may have the same structure as the adhesive layer 26 .

At least a part of this embodiment can be implemented in combination with other embodiments described in this specification as appropriate.

Embodiment 2

In this embodiment, a method of manufacturing an input device included in a display device according to an embodiment of the present invention will be described with reference to FIGS. 8A to 15C . Here, the case where an electrostatic capacitance type touch sensor is used as an input device is demonstrated.

<2-1. Manufacturing method 1>

First, an example of a manufacturing method according to an embodiment of the present invention will be described with reference to FIGS. 8A to 11 .

First, the substrate 161 is prepared. The substrate 161 preferably has a relatively flat surface. As the substrate 161, a glass substrate or a resin substrate may be used, or a non-translucent substrate such as a metal substrate and a ceramic substrate may be used. Next, the release layer 162 , the layer to be released 163 , and the insulating layer 164 are stacked on the substrate 161 (see FIG. 8A ).

Here, as the peeling layer 162 and the peelable layer 163, a combination of materials that can be peeled off at the interface with each other is used. Preferably, a metal or a metal oxide is used as the peeling layer 162 , and a resin material such as polyimide is used as the peeling layer 163 . Thereby, the structure which can be peeled by changing the adhesiveness of both can be implemented.

As a material that can be used for the peeling layer 162 , various metals such as titanium, molybdenum, aluminum, tungsten, and tantalum, or alloys thereof can be used, for example.

In addition, various metal oxides can be used as a material that can be used for the peeling layer 162 . For example, titanium oxide, molybdenum oxide, aluminum oxide, tungsten oxide, indium tin oxide, indium zinc oxide, In-Ga-Zn oxide, etc. are mentioned. In particular, as the peeling layer 162, titanium or titanium oxide is preferably used.

Alternatively, a metal such as tungsten is used as the peeling layer 162 , and an oxide such as silicon oxide is used as the peeling layer 163 . At this time, the surface of the metal is oxidized due to contact with the oxide, thereby forming an oxide (eg, tungsten oxide) of the metal. In addition, heat treatment may be performed to promote the oxidation reaction after the formation of the peeled layer 163 . Here, peeling can be performed at the interface between the peeling layer 162 and the peeled layer 163 by applying an external force for physically peeling off the peeling layer 162 .

In the present embodiment, titanium oxide and polyimide are used as the peeling layer 162 and the peeled layer 163, respectively. Further, the thickness of the peeled layer 163 is preferably 10 μm or less, more preferably 0.1 μm or more and 5 μm or less, and further preferably 0.5 μm or more and 3 μm or less. By setting the thickness of the peeling layer 163 within the above range, the peeling layer 163 can be appropriately removed after the interface between the peeling layer 162 and the peeling layer 163 is separated. Moreover, as this removal process, oxygen plasma process, the wet etching process using a chemical|medical solution, etc. are mentioned, for example.

As the insulating layer 164, an insulating film that is transparent to visible light can be used. For example, an inorganic insulating film such as silicon oxide, silicon nitride, or aluminum oxide can be used, and an organic insulating film such as resin can also be used.

Next, an opening 165 reaching the peeled layer 163 is formed in the insulating layer 164 (see FIG. 8B ).

By forming the opening portion 165, a connecting portion for realizing electrical connection between the touch sensor and the outside can be provided.

Next, a conductive layer 179a, a conductive layer 179b, an insulating layer 180, a light shielding layer 181, a color layer 182, an insulating layer 183, and a conductive layer 170 are formed on the insulating layer 164 (see FIG. 8C).

In addition, the conductive layer 179a, the conductive layer 179b, the insulating layer 180, the light shielding layer 181, the color layer 182, and the insulating layer 183 correspond to the element layer 22 shown in FIG. 1B.

The conductive layer 179a has a function of a pixel electrode, and the conductive layer 179b has a function of a connection electrode. As the conductive layers 179a and 179b, for example, conductive films that transmit visible light, such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and In-Sn-Si oxide, may be used.

The insulating layer 180 is formed using an inorganic material, an organic material, or the like. As an inorganic material, silicon oxide, silicon oxynitride, silicon nitride, etc. are mentioned, for example. As an organic material, acrylic resin, polyimide, etc. are mentioned.

As the light shielding layer 181, a material that suppresses light transmission can be used. Thereby, the light shielding layer 181 can be used as a black matrix. Specifically, a resin containing a pigment or dye may be used for the light shielding layer 181 . For example, a resin in which carbon black is dispersed can be used for the light-shielding film. Alternatively, an inorganic compound, an inorganic oxide, a composite oxide including a solid solution of a plurality of inorganic oxides, or the like may be used for the light shielding layer 181 . Specifically, a black chrome film, a film containing copper (II) oxide, a film containing copper chloride or tellurium chloride can be used for the light shielding layer 181 .

As the color layer 182, a material that transmits light of a predetermined color can be used. Thus, the color layer 182 can be used as a color filter.

For example, a material that transmits blue light, a material that transmits green light, or a material that transmits red light may be used for the color layer 182 . Thereby, the width of the spectrum of the light transmitted through the color layer 182 can be narrowed, and a clear image can be displayed.

For example, a blue light absorbing material, a green light absorbing material, or a red light absorbing material may be used for the color layer 182 . Specifically, a material that transmits yellow light, a material that transmits magenta (magenta) light, or a material that transmits cyan light (cyan) can be used for the color layer 182 . Thereby, the width of the spectrum of the light absorbed by the color layer 182 can be narrowed, and a bright image can be displayed.

The insulating layer 183 may use the same material as the insulating layer 180 .

As the conductive layer 170, a metal layer such as copper or nickel is preferably used. The conductive layer 170 is formed into an island shape by processing it so as to form the wiring in the vertical direction and the wiring in the lateral direction after forming the conductive film. In addition, a portion of the conductive layer 170 extends and contacts the conductive layer 179b.

Next, the surface of the conductive layer 170 is oxidized to form a dark layer 171b, a dark layer 172b, and a dark layer 173b (see FIG. 8D).

As the above-mentioned oxidation treatment, oxygen plasma treatment or the like can be used. By forming the dark layer 171b, the dark layer 172b, and the dark layer 173b, the reflectivity of the conductive layer 170 can be reduced. In addition, the dark layer 171b, the dark layer 172b, and the dark layer 173b may not exhibit sufficient conductivity. In addition, regions having conductivity equal to that of the conductive layer 170 that are not oxidized by the oxidation treatment are the conductive layer 171a, the conductive layer 172a, and the conductive layer 173a.

The conductive layer including the conductive layer 171 a and the dark layer 171 b is used as the wiring 171 . The conductive layer including the conductive layer 172 a and the dark layer 172 b is used as the wiring 172 . In addition, the conductive layer including the conductive layer 173 a and the dark layer 173 b is used as the wiring 173 .

Next, an insulating layer 166 is formed on the wirings 171 , 172 , and 173 . The insulating layer 166 can be formed using the same material as the peeled layer 163 . Then, wirings 174 that electrically connect adjacent wirings 171 to each other and electrically connect the wirings 171 and 173 are formed (see FIG. 8E ).

The wirings 171 , 172 , and 173 , the insulating layer 166 , and the wiring 174 correspond to the input device 25 shown in FIG. 1B .

The wiring 174 can be formed by the following processes: providing a conductive layer in the openings provided in the insulating layer 166, the dark layer 171b and the dark layer 173b; processing the conductive layer into a desired shape; and performing oxidation treatment. Like the wiring 171 and the like, the wiring 174 includes a conductive layer 174a and a conductive layer 174b provided by oxidation treatment. By providing the opening in the dark layer 171b, the conductive layer 174a and the conductive layer 171a can be electrically connected. In addition, by providing an opening in the dark layer 173b, the conductive layer 174a and the conductive layer 173a can be electrically connected.

Next, the substrate 168 is attached to the insulating layer 166 and the wiring 174 via the adhesive layer 187 (see FIG. 9A ).

Here, the substrate 168 corresponds to the second substrate 12 shown in FIGS. 1A and 1B and the like.

Next, light irradiation is performed on the processing region (region including the peeling layer 162 and the peeled layer 163 ) from the side of the substrate 161 (see FIG. 9B ).

By this light irradiation, the peeling layer 162 , the peeled layer 163 , and the interface thereof are heated to cause structural changes, whereby the adhesion between the two can be reduced.

As the light irradiated at this time, for example, a short-wavelength laser beam can be used. Typically, an excimer laser capable of irradiating light having a wavelength of 351 nm to 353 nm (XeF) or 308 nm (XeCl) or the like can be used. Alternatively, frequency doublings (515 nm, 532 nm, etc.) or frequency triples (343 nm, 355 nm, etc.) of solid-state lasers (YAG lasers, fiber lasers, etc.) can also be used.

Here, the laser beam is preferably a linear beam. By moving the workpiece horizontally in the short-axis direction of the linear beam while irradiating the linear beam, the entire workpiece can be efficiently irradiated with the laser beam.

Next, the interface between the peeling layer 162 and the layer to be peeled 163 or the vicinity of the interface is peeled off (see FIG. 9C ).

For example, the above-described peeling can be performed by fixing the substrate 161 using a suction stage or the like, and applying physical force to move the substrate 168 upward.

Next, the peeled layer 163 is removed by ashing treatment, and the insulating layer 164 and the conductive layer 179b formed in the opening portion 165 are exposed (see FIG. 9D ).

Through the above process, the device layer 22 and the input device 25 can be formed on one surface of the substrate 168 .

Next, referring to FIGS. 10A to 10C , the process of laminating the element layer 21 , the element layer 22 and the input device 25 shown in FIGS. 1A and 1B will be described. In addition, FIGS. 10A to 10C correspond to cross-sectional process diagrams along X1 - X2 shown in FIG. 1A .

First, the element layer 21 is provided on the first substrate 11 (see FIG. 10A ).

The wiring 33b is provided on the first substrate 11 .

Next, the element layer 21 is bonded to the substrate 168 on which the element layer 22 and the input device 25 are provided. In addition, the substrate 11 is sealed with the insulating layer 164 formed under the substrate 168 using the adhesive layer 26 . Then, the LC layer 21b_LC is formed between the LC layer 21b and the insulating layer 164 (see FIG. 10B ).

Next, the driver circuit 30 is mounted so as to be electrically connected to the wiring 33 b provided on the substrate 11 . Then, the conductive layer 179b electrically connected to the conductive layer 173a in the wiring 173 serving as the touch sensor of the input device 25 is electrically connected to the wiring 33b using the FPC 32 (refer to FIG. 10C ).

Through the above process, the display device 10 shown in FIG. 1A and FIG. 1B can be formed.

Note that, in the processes shown in FIGS. 8A to 10C , the structure in which the openings 165 are provided in the peeled layer 163 is described, but the invention is not limited to this, and the openings 165 may not be provided. FIG. 11 shows an example of a structure in which the opening portion 165 is not provided.

FIG. 11 is a cross-sectional view of a modified example of the display device 10 shown in FIG. 10C . In FIG. 11 , the peeled layer 163 is provided and the conductive layers 179 a and 179 b are provided on the peeled layer 163 , but the opening 165 is not provided. Then, the peeling layer 162 and the peeled layer 163 may be separated, and the peeled layer 163 may be removed to form the display device 10 . When the structure shown in FIG. 11 is adopted, the LC layer 21b is in contact with 179a serving as a pixel electrode.

<2-2. Manufacturing method 2>

Next, a method different from the manufacturing method shown in <2-1. Manufacturing method 1> will be described with reference to FIGS. 12A to 15C . 12A to 15C are cross-sectional views illustrating a method of manufacturing the display device 10 shown in FIG. 3 .

First, the substrate 161a is prepared. Next, the peeling layer 162a, the peeling-off layer 163a, and the insulating layer 164a are formed on the substrate 161a (see FIG. 12A ).

The substrate 161a, peeling layer 162a, peeling layer 163a, and insulating layer 164a can be formed by the same method as the substrate 161, peeling layer 162, peeling layer 163, and insulating layer 164 described above.

Next, a conductive layer 179, an insulating layer 180a, a light shielding layer 181a, a color layer 182a, and an insulating layer 183a are formed on the insulating layer 164a (see FIG. 12B).

In addition, the conductive layer 179, the insulating layer 180a, the light shielding layer 181a, the color layer 182a, and the insulating layer 183a on the insulating layer 164a correspond to the element layer 22 shown in FIG. 3 .

The conductive layer 179, the insulating layer 180a, the light shielding layer 181a, the colored layer 182a, and the insulating layer 183a can be formed by the same method as the conductive layers 179a, 179b, the insulating layer 180, the light shielding layer 181, the colored layer 182, and the insulating layer 183 described above. .

Next, the adhesive layer 184 and the light diffusing plate 185 are formed on the insulating layer 183a. In addition, the light diffusing plate 185 corresponds to the light diffusing plate 23 shown in FIG. 3 , and the adhesive layer 184 corresponds to the adhesive layer 26 a shown in FIG. 3 .

Next, the peeling layer 162a and the peeling-off layer 163a are separated (see FIGS. 12D and 12E ).

The process of separating the peeling layer 162a from the peeled layer 163a can be performed using the same method as the process of separating the peeling layer 162a and the peeled layer 163a described above.

As shown in FIG. 12E, the element layer 22, the adhesive layer 26a, and the light diffusing plate 23 are formed in this order.

Next, the substrate 161b is prepared. Then, the peeling layer 162b, the peeling-off layer 163b, and the insulating layer 164 are formed on the substrate 161b (see FIG. 13A ).

Next, openings 165 are formed in the insulating layer 164 (see FIG. 13B ).

Next, the conductive layer 170 , the wiring 171 , the wiring 172 , the wiring 173 , the insulating layer 166 , and the wiring 174 are formed on the insulating layer 164 (see FIGS. 13C , 13D and 13E ).

In addition, the conductive layer 170 , the wiring 171 , the wiring 172 , the wiring 173 , the insulating layer 166 , and the wiring 174 correspond to the input device 25 a shown in FIG. 3 .

Next, a polarizing plate 167, an adhesive layer 169, and a substrate 168 are formed on the insulating layer 166 and the wiring 174 (see FIG. 14A).

In addition, the polarizing plate 167 corresponds to the polarizing plate 25b shown in FIG. 3 . In addition, as the polarizing plate 167, for example, a linear polarizing plate or a circular polarizing plate can be used. In particular, when a reflective liquid crystal element is used, a circularly polarizing plate is appropriately used. As a circular polarizing plate, the polarizing plate which laminated|stacked a linear polarizing plate and a quarter wave retardation plate, for example can be used. By using a circular polarizing plate, it is possible to appropriately suppress the reflection of external light.

In addition, as the polarizing plate 167, an organic layer containing a dichroic dye in which the long axes of molecules are aligned in a predetermined direction may be used. The organic layer functions as a polarizer. In addition, it is preferable to use a liquid crystal material in order to align the long axes of the molecules of the dichroic dye in one predetermined direction. In addition, after aligning the long axes of the molecules in a predetermined one direction using a liquid crystal material, the monomer added together with the dichroic dye may be cured to form a polymer.

As the adhesive layer 169, various curable adhesives, such as a photocurable adhesive such as an ultraviolet curable adhesive, a reaction curable adhesive, a thermosetting adhesive, and an anaerobic adhesive, can be used. Materials that can be used for the adhesive layer 169 will be described in detail later.

As the substrate 168, a thin-film substrate subjected to anti-reflection treatment or anti-glare treatment can be used. In addition, the substrate 168 corresponds to the second substrate 12 shown in FIGS. 1A and 1B .

Next, the peeling layer 162b and the peeling-off layer 163b are separated (see FIGS. 14B , 14C, and 14D).

The method by which the peeling layer 162b and the peeling layer 163b can be separated is the same as that of the peeling layer 162 and the peeling layer 163 described above.

Elements corresponding to the input device 25 shown in FIG. 3 are formed under the substrate 168 shown in FIG. 14D . In addition, as shown in Fig. 14D, a portion of the input device 25 may also include an adhesive layer 169.

Next, the substrate 168 and the element layer 22 are bonded together using the adhesive layer 186 (see FIG. 15A ).

In addition, the adhesive layer 186 is disposed between the light diffusing plate 185 and the insulating layer 164 .

Next, the element layer 21 is bonded to the substrate 168 on which the input device 25 and the element layer 22 are provided. Further, the substrate 11 is sealed with the insulating layer 164 formed under the substrate 168 using the adhesive layer 26 . Then, the LC layer 21b_LC is formed between the LC layer 21b and the conductive layer 179 (see FIG. 15B ).

Next, the driver circuit 30 is mounted so as to be electrically connected to the wiring 33 b provided on the substrate 11 . Then, the conductive layer 173a in the wiring 173 serving as the touch sensor of the input device 25 is electrically connected to the wiring 33b using the FPC 32 (refer to FIG. 15C ).

Through the above process, the display device 10 shown in FIG. 3 can be formed.

At least a part of this embodiment can be implemented in combination with other embodiments described in this specification as appropriate.

Embodiment 3

In this embodiment mode, a display device and a method for driving the display device according to an embodiment of the present invention will be described.

<3-1. Concept of display device>

As the display device according to one embodiment of the present invention, for example, a hybrid display can be suitably used. The hybrid display can perform hybrid display.

Hybrid display refers to a method of displaying text or images in a panel that uses both reflected light and self-illumination to complement each other with color tone or light intensity. In addition, the hybrid display refers to a method of displaying characters and/or images in one pixel or one sub-pixel using light from a plurality of display elements. However, when a hybrid display that performs hybrid display is viewed locally, it may include: a pixel or sub-pixel that performs display using any one of a plurality of display elements; and a display that uses two or more of the plurality of display elements. The displayed pixel or subpixel.

Note that in this specification and the like, the hybrid display satisfies any one or more of the above expressions.

Furthermore, hybrid displays include multiple display elements in one pixel or one sub-pixel. Examples of the plurality of display elements include reflective elements that reflect light and self-luminous elements that emit light. The reflective element and the self-luminous element can be independently controlled. The hybrid display has a function of displaying characters and/or images using either or both of reflected light and self-illumination in the display unit.

The display device of one embodiment of the present invention may include a pixel provided with a first display element that reflects visible light. Furthermore, a pixel provided with a second display element emitting visible light may be included. In addition, a pixel provided with a first display element and a second display element may be included.

In this embodiment mode, a display device including a first display element that reflects visible light and a second display element that emits visible light will be described.

The display device has a function of displaying an image using one or both of the first light reflected by the first display element and the second light emitted by the second display element. In addition, the display device has a function of expressing gray scales by controlling the light amount of the first light reflected by the first display element and the light amount of the second light emitted by the second display element.

In addition, the display device preferably includes a first pixel that expresses gray scales by controlling the amount of light reflected by the first display element and a second pixel that expresses gray scales by controlling the amount of light emitted from the second display element . The first pixel and the second pixel are arranged in a matrix, for example, to constitute a display unit.

In addition, it is preferable to set the same number of first pixels and second pixels with the same spacing in the display area. At this time, a unit including adjacent first pixels and second pixels may be referred to as a pixel unit. Thereby, as described below, an image displayed only by a plurality of first pixels, an image displayed by only a plurality of second pixels, and an image displayed by a plurality of first pixels and a plurality of second pixels can be displayed in the same display area of both displayed images.

As the first display element included in the first pixel, an element that reflects external light for display can be used. Because such an element does not include a light source, power consumption during display can be made extremely small.

As the first display element, a reflective liquid crystal element can be typically used. Alternatively, as the first display element, not only a shutter-type MEMS (Micro Electro Mechanical System) element, an optical interference-type MEMS element, but also an applied microcapsule method, an electrophoresis method, and an electrowetting method may be used. , electronic powder fluid (registered trademark) method, etc.

As the second display element included in the second pixel, an element that includes a light source and performs display using light from the light source can be used. In particular, it is preferable to use an electroluminescence element capable of extracting light emission from a light-emitting substance by applying an electric field. Since the brightness and chromaticity of light emitted by such pixels are not affected by external light, such pixels can display images with high color reproducibility (wide color gamut) and high contrast, that is, sharp images.

As the second display element, for example, OLED (Organic Light Emitting Diode: Organic Light Emitting Diode), LED (Light Emitting Diode: Light Emitting Diode), QLED (Quantum-dot Light Emitting Diode: Quantum Dot Light Emitting Diode) can be used ), semiconductor lasers and other self-luminous light-emitting elements. Alternatively, as the display element included in the second pixel, a backlight that is a light source and a transmissive liquid crystal element that controls the amount of transmitted light from the backlight may be used in combination.

For example, the first pixel may include a sub-pixel exhibiting white (W) light or a sub-pixel exhibiting red (R) light, a sub-pixel exhibiting green (G) light, and a sub-pixel exhibiting blue (B) light. In addition, for example, the second pixel may similarly include a sub-pixel that exhibits white (W) light, or a sub-pixel that exhibits red (R) light, a sub-pixel that exhibits green (G) light, and a sub-pixel that exhibits blue (B) light. subpixel. In addition, each of the first pixel and the second pixel may include sub-pixels of four or more colors. The greater the variety of sub-pixels, the more power consumption can be reduced and the color reproducibility improved.

One embodiment of the present invention can switch between a first mode in which the image is displayed by the first pixel, a second mode in which the image is displayed by the second pixel, and a third mode in which the image is displayed by the first pixel and the second pixel. In addition, as shown in Embodiment 1, a composite video may be displayed by inputting video signals different from each other to the first pixel and the second pixel.

The first mode is a mode in which an image is displayed using the light reflected by the first display element. No light source is required in the first mode, so it is a very low power consumption drive mode. For example, the first mode is effective when the illuminance of the outside light is sufficiently high and the outside light is white light or close to white light. The first mode is suitable for displaying text information such as books or documents, for example. In addition, since reflected light is used, the display is less irritating to the eyes and less likely to cause eye fatigue.

The second mode is a mode in which an image is displayed using light emitted by the second display element. Therefore, an extremely clear (high contrast and color reproducibility) image can be displayed regardless of the illuminance or chromaticity of the external light. For example, the second mode is effective when the illuminance of the outside light is extremely low, such as at night or in a dark room. In addition, when the illuminance of the outside light is low, the bright display may be dazzling to the user. In order to prevent this problem, it is preferable to lower the brightness in the second mode. As a result, not only glare can be reduced, but also power consumption can be reduced. The second mode is suitable for displaying clear images or smooth moving images.

The third mode is a mode in which an image is displayed using both the light reflected by the first display element and the light emitted by the second display element. Specifically, driving is performed in such a way that one color is expressed by mixing the color of the light presented by the first pixel and the color of the light presented by the second pixel adjacent to the first pixel. This makes it possible to display a clearer image than the first mode with less power consumption than in the second mode. For example, the third mode is effective under indoor lighting, when the illuminance of external light such as morning or evening is low, or when the chromaticity of the external light is not white.

<3-2. Configuration example of display device>

Next, a more specific example of one embodiment of the present invention will be described with reference to the drawings.

FIG. 16 is a diagram illustrating a pixel array 40 included in a display device according to an embodiment of the present invention. The pixel array 40 includes a plurality of pixel units 45 arranged in a matrix. The pixel unit 45 includes pixels 46 and 47 .

FIG. 16 shows an example of a case where both the pixel 46 and the pixel 47 include display elements corresponding to three colors of red (R), green (G), and blue (B).

The pixel 46 includes a display element 46R corresponding to red (R), a display element 46G corresponding to green (G), and a display element 46B corresponding to blue (B). The display elements 46R, 46G, and 46B are all first display elements that utilize light from a light source.

The pixel 47 includes a display element 47R corresponding to red (R), a display element 47G corresponding to green (G), and a display element 47B corresponding to blue (B). The display elements 47R, 47G, and 47B are all second display elements that utilize reflection of external light.

The above is the description of the configuration example of the display device.

<3-3. Configuration example of pixel unit>

Next, the pixel unit 45 will be described with reference to FIGS. 17A , 17B, and 17C. 17A , 17B and 17C are schematic diagrams showing structural examples of the pixel unit 45 .

Pixel 46 includes display element 46R, display element 46G, and display element 46B. The display element 46R includes a light source, and emits red light R2 having luminance based on a grayscale value corresponding to red included in the second grayscale value input to the pixel 46 toward the display surface side. Similarly, the display element 46G and the display element 46B also emit the green light G2 or the blue light B2 to the display surface side, respectively.

The pixel 47 includes a display element 47R, a display element 47G, and a display element 47B. The display element 47R reflects external light, and emits red light R1 having luminance based on a grayscale value corresponding to red included in the first grayscale value input to the pixel 47 toward the display surface side. Similarly, the display element 47G and the display element 47B also emit the green light G1 or the blue light B1 to the display surface side, respectively.

[First Mode]

FIG. 17A shows an example of an operation mode in which the display element 47R, the display element 47G, and the display element 47B that reflect external light are driven to display an image. As shown in FIG. 17A , when the illuminance of the external light is sufficiently high, the pixel unit 45 mixes only the colors of the light (light R1 , light G1 , and light B1 ) from the pixel 47 without driving the pixel 46 . The side of the display surface emits light 55 of a specified color. Thereby, it is possible to drive with extremely low power consumption.

[Second Mode]

FIG. 17B shows an example of an operation mode in which the display element 46R, the display element 46G, and the display element 46B are driven to display images. As shown in FIG. 17B , the pixel unit 45 may mix only the colors of the light (light R2 , light G2 , and light B2 ) from the pixel 46 without driving the pixel 47 when the illuminance of the external light is extremely low, for example. Light 55 of a specified color is emitted toward the display surface side. Thereby, a clear video can be displayed. In addition, by reducing the brightness when the illuminance of the external light is low, not only the glare of the user can be reduced, but also the power consumption can be reduced.

[Third Mode]

17C shows an example of an operation mode in which the display element 47R reflecting external light, the display element 47G, the display element 47B, and the display element 46R, the display element 46G, and the display element 46B that emit light are driven to display images. As shown in FIG. 17C , the pixel unit 45 can emit light 55 of a specified color toward the display surface side by mixing the colors of the six lights of light R1, light G1, light B1, light R2, light G2, and light B2.

The above is the description of the configuration example of the pixel unit 45 .

At least a part of this embodiment can be implemented in combination with other embodiments described in this specification as appropriate.

Embodiment 4

Next, an example of a display panel that can be used in the display device according to one embodiment of the present invention will be described. The display panel exemplified below is a display panel that includes two elements, a reflective liquid crystal element and a light-emitting element, and is capable of displaying in two modes, a transmissive mode and a reflective mode.

<4-1. Configuration example of display device>

FIG. 18A is a block diagram showing an example of the configuration of the display device 400 . The display device 400 includes a plurality of pixels 410 arranged in a matrix in the display unit 362 . In addition, the display device 400 includes a circuit GD and a circuit SD. In addition, a plurality of wirings G1, a plurality of wirings G2, a plurality of wirings ANO, and a plurality of wirings CSCOM electrically connected to the plurality of pixels 410 and the circuit GD arranged in the direction R are included. In addition, a plurality of wirings S1 and a plurality of wirings S2 electrically connected to the plurality of pixels 410 and the circuit SD arranged in the direction C are included.

Here, for simplicity, a configuration including one circuit GD and one circuit SD is shown, but circuits GD and SD for driving liquid crystal elements and circuits GD and SD for driving light-emitting elements may be provided separately.

The pixel 410 includes a reflective liquid crystal element and a light-emitting element. In the pixel 410, the liquid crystal element and the light emitting element have portions overlapping each other.

FIG. 18B1 shows an example of the structure of the conductive layer 311 b included in the pixel 410 . The conductive layer 311b is used as a reflective electrode of the liquid crystal element in the pixel 410 . An opening 451 is provided in the conductive layer 311b.

In FIG. 18B1 , the light emitting element 360 located in the region overlapping with the conductive layer 311 b is shown by a dotted line. The light emitting element 360 overlaps with the opening 451 included in the conductive layer 311b. Thereby, the light emitted from the light emitting element 360 is emitted to the display surface side through the opening 451 .

Pixels 410 adjacent in the direction R in FIG. 18B1 are pixels corresponding to different colors. At this time, as shown in FIG. 18B1 , in the two adjacent pixels in the direction R, it is preferable that the openings 451 are provided in different positions of the conductive layer 311b so as not to be provided on a line. Thereby, the two light-emitting elements 360 can be arranged separately, and it is possible to suppress a phenomenon (also referred to as crosstalk) in which light emitted by the light-emitting elements 360 is incident on a color layer included in an adjacent pixel 410 . In addition, since two adjacent light-emitting elements 360 can be arranged separately, even if the EL layers of the light-emitting elements 360 are separately fabricated using a shadow mask or the like, a high-resolution display device can be realized.

Alternatively, the arrangement shown in FIG. 18B2 may be employed.

When the ratio of the total area of the non-opening portion to the total area of the opening 451 is too large, the display using the liquid crystal element becomes dark. In addition, when the ratio of the total area of the non-opening portion to the total area of the opening 451 is too small, the display using the light-emitting element 360 becomes dark.

In addition, when the area of the opening 451 provided in the conductive layer 311b used as the reflective electrode is too small, the extraction efficiency of the light emitted from the light-emitting element 360 becomes low.

The shape of the opening 451 may be, for example, a polygonal shape, a quadrangular shape, an oval shape, a circular shape, a cross shape, or the like. In addition, elongated strip-like, slit-like, or grid-like shapes may be used. In addition, the openings 451 may be arranged so as to be close to adjacent pixels. Preferably, the openings 451 are arranged close to other pixels displaying the same color. Thereby, the occurrence of crosstalk can be suppressed.

<4-2. Example of circuit configuration of pixel>

FIG. 19 is a circuit diagram showing a configuration example of the pixel 410 . FIG. 19 shows two adjacent pixels 410 .

The pixel 410 includes a switch SW1, a capacitive element C1, a liquid crystal element 340, a switch SW2, a transistor M, a capacitive element C2, a light-emitting element 360, and the like. In addition, the wiring G1 , the wiring G2 , the wiring ANO, the wiring CSCOM, the wiring S1 , and the wiring S2 are electrically connected to the pixel 410 . In addition, FIG. 19 also shows the wiring VCOM1 electrically connected to the liquid crystal element 340 and the wiring VCOM2 electrically connected to the light emitting element 360 .

FIG. 19 shows an example of a case where transistors are used for the switch SW1 and the switch SW2.

In the switch SW1 , the gate is connected to the wiring G1 , one of the source and the drain is connected to the wiring S1 , and the other of the source and drain is connected to one electrode of the capacitive element C1 and one electrode of the liquid crystal element 340 . In the capacitive element C1, the other electrode is connected to the wiring CSCOM. In the liquid crystal element 340, the other electrode is connected to the wiring VCOM1.

In the switch SW2, the gate is connected to the wiring G2, one of the source and the drain is connected to the wiring S2, and the other of the source and drain is connected to one electrode of the capacitive element C2 and the gate of the transistor M. In the capacitive element C2, the other electrode is connected to one of the source and drain of the transistor M and the wiring ANO. In the transistor M, the other of the source and the drain is connected to one electrode of the light-emitting element 360 . In the light-emitting element 360, the other electrode is connected to the wiring VCOM2.

FIG. 19 shows an example in which the transistor M includes two gates sandwiching a semiconductor and the gates are connected to each other. Thereby, the amount of current that can flow through the transistor M can be increased.

In addition, a signal for controlling the switch SW1 to a conductive state or a non-conductive state may be supplied to the wiring G1. A predetermined potential can be supplied to the wiring VCOM1. A signal for controlling the alignment state of the liquid crystal of the liquid crystal element 340 may be supplied to the wiring S1 . A predetermined potential can be supplied to the wiring CSCOM.

In addition, a signal for controlling the switch SW2 to a conductive state or a non-conductive state may be supplied to the wiring G2. The wiring VCOM2 and the wiring ANO can be supplied with a potential that generates a potential difference for causing the light-emitting element 360 to emit light. A signal for controlling the conduction state of the transistor M may be supplied to the wiring S2.

The pixel 410 shown in FIG. 19 can be driven by the signals supplied to the wiring G1 and the wiring S1 and displayed by the optical modulation of the liquid crystal element 340 when the pixel 410 is displayed in the reflection mode, for example. When displaying in the transmissive mode, the light-emitting element 360 can be driven by the signals supplied to the wiring G2 and the wiring S2 to emit light for display. In addition, when driving in two modes, the driving can be performed using the signals supplied to the wiring G1 , the wiring G2 , the wiring S1 , and the wiring S2 , respectively.

Note that although FIGS. 20A and 20B illustrate an example in which one pixel 410 includes one liquid crystal element 340 and one light emitting element 360, it is not limited to this. Fig. 20A shows an example in which one pixel 410 includes one liquid crystal element 340 and four light emitting elements 360 (light emitting elements 360r, 360g, 360b, 360w).

In FIG. 20A , in addition to the example shown in FIG. 19 , the wiring G3 and the wiring S3 are connected to the pixel 410 .

In the example shown in FIG. 20A , for example, as the four light-emitting elements 360 , light-emitting elements exhibiting red (R), green (G), blue (B), and white (W), respectively, can be used. In addition, as the liquid crystal element 340, a reflection type liquid crystal element that exhibits white can be used. Thereby, when displaying in the reflection mode, white display with high reflectivity can be performed. In addition, when displaying in the transmissive mode, high color rendering can be displayed with low power consumption.

In addition, FIG. 20B shows a configuration example of the pixel 410 . The pixel 410 includes a light-emitting element 360w overlapping the opening included in the electrode 311 , a light-emitting element 360r arranged around the electrode 311 , a light-emitting element 360g , and a light-emitting element 360b . The light-emitting element 360r, the light-emitting element 360g, and the light-emitting element 360b preferably have almost the same light-emitting area.

<4-3. Example of the structure of the display panel>

FIG. 21 is a schematic perspective view of a display panel 300 according to an embodiment of the present invention. The display panel 300 includes a structure in which the substrate 351 and the substrate 361 are bonded together. In FIG. 21 , the substrate 361 is indicated by a dotted line.

The display panel 300 includes a display portion 362, circuits 364, wirings 365, and the like. The substrate 351 is provided with, for example, a circuit 364, a wiring 365, a conductive layer 311b used as a pixel electrode, and the like. In addition, FIG. 21 shows an example in which the IC 373 and the FPC 372 are mounted on the substrate 351 . Therefore, the structure shown in FIG. 21 can be said to be a display module including the display panel 300 , the FPC 372 and the IC 373 .

As the circuit 364, for example, a circuit used as a scanning line driver circuit can be used.

The wiring 365 has a function of supplying signals or power to the display unit and the circuit 364 . This signal or power is input to the wiring 365 from the outside via the FPC 372 or from the IC 373 .

FIG. 21 shows an example in which the IC 373 is provided on the substrate 351 by a COG (Chip On Glass) method or the like. For example, an IC used as a scanning line driver circuit, a signal line driver circuit, or the like can be applied to IC373. In addition, when the display panel 300 includes a circuit used as a scan line driver circuit or a signal line driver circuit, or a circuit used as a scan line driver circuit or a signal line driver circuit is provided externally and is used to drive the display panel 300 through the input of the FPC372 The IC373 can also not be set when the signal, etc. In addition, the IC373 may be mounted on the FPC372 by a COF (Chip On Film) method or the like.

FIG. 21 shows an enlarged view of a part of the display unit 362 . In the display portion 362, conductive layers 311b included in a plurality of display elements are arranged in a matrix. The conductive layer 311b has a function of reflecting visible light and is used as a reflective electrode of the liquid crystal element 340 described below.

Furthermore, as shown in FIG. 21, the conductive layer 311b includes openings. Furthermore, the light emitting element 360 is included on the substrate 351 side of the conductive layer 311b. Light from the light emitting element 360 is emitted to the substrate 361 side through the opening of the conductive layer 311b.

In addition, a touch sensor may be provided on the substrate 361 . For example, a structure in which a sheet-like capacitive touch sensor 366 is provided so as to overlap the display portion 362 may be employed. Alternatively, a touch sensor may also be disposed between the substrate 361 and the substrate 351 . When the touch sensor is provided between the substrate 361 and the substrate 351, either an electrostatic capacitive touch sensor or an optical touch sensor using a photoelectric conversion element can be used.

<4-4. Example of sectional structure>

22 shows an example of a cross section of a part of the area including the FPC 372, a part of the area including the circuit 364, a part of the area including the display part 362, and the touch sensor 366 in the display panel illustrated in FIG. 21 .

The display panel includes the insulating layer 220 between the substrate 351 and the substrate 560 . In addition, the light emitting element 360 , the transistor 201 , the transistor 205 , the transistor 206 , the color layer 134 , and the like are included between the substrate 351 and the insulating layer 220 . In addition, the liquid crystal element 340 , the insulating layer 180 , the color layer 131 , the insulating layer 121 , the touch sensor 366 and the like are included between the insulating layer 220 and the substrate 560 . In addition, the touch sensor 366 is bonded to the insulating layer 121 via the adhesive layer 176 , and the substrate 351 is bonded to the light-emitting element 360 via the adhesive layer 142 .

The transistor 206 is electrically connected to the liquid crystal element 340 , and the transistor 205 is electrically connected to the light-emitting element 360 . Since both the transistor 205 and the transistor 206 are formed on the substrate 351 side of the insulating layer 220, they can be manufactured by the same process.

The substrate 560 is provided with a touch sensor 366 , a color layer 131 , a light shielding layer 132 , an insulating layer 121 , an insulating layer 180 , a conductive layer 313 used as a common electrode of the liquid crystal element 340 , an alignment film 133 b , an insulating layer 117 , and the like. The insulating layer 117 is used as a spacer for maintaining the cell gap of the liquid crystal element 340 .

On the substrate 351 side of the insulating layer 220, insulating layers such as the insulating layer 211, the insulating layer 212, the insulating layer 213, the insulating layer 214, and the insulating layer 215 are provided. A part of the insulating layer 211 is used as a gate insulating layer of each transistor. The insulating layer 212, the insulating layer 213, and the insulating layer 214 are provided so as to cover the respective transistors. In addition, the insulating layer 215 is provided so as to cover the insulating layer 214 . The insulating layer 214 and the insulating layer 215 function as a planarization layer. In addition, the case where three layers of the insulating layer 212, the insulating layer 213, and the insulating layer 214 are included as the insulating layer covering the transistor etc. is shown here, but the insulating layer is not limited to this, and may be four or more layers, a single layer, or two layers. layer. If not required, the insulating layer 214 serving as a planarization layer may not be provided.

The transistor 201 , the transistor 205 and the transistor 206 include a conductive layer 221 whose part is used as a gate electrode, a conductive layer 222 whose part is used as a source electrode or a drain electrode, and a semiconductor layer 231 . Here, the same hatching is attached to a plurality of layers obtained by processing the same conductive film.

The liquid crystal element 340 is a reflection type liquid crystal element. The liquid crystal element 340 has a laminated structure in which a conductive layer 311a, a liquid crystal 312, and a conductive layer 313 are laminated. In addition, a conductive layer 311b that reflects visible light is provided in contact with the substrate 351 side of the conductive layer 311a. The conductive layer 311b includes the opening 251 . In addition, the conductive layer 311a and the conductive layer 313 contain a material that transmits visible light. Further, an alignment film 133 a is provided between the liquid crystal 312 and the conductive layer 311 a, and an alignment film 133 b is provided between the liquid crystal 312 and the conductive layer 313 .

In the liquid crystal element 340, the conductive layer 311b has a function of reflecting visible light, and the conductive layer 313 has a function of transmitting visible light. The light incident from the side of the substrate 560 is transmitted through the conductive layer 313 and the liquid crystal 312, and is reflected by the conductive layer 311b. Then, it passes through the liquid crystal 312 and the conductive layer 313 again and reaches the substrate 560 . At this time, the alignment of the liquid crystal is controlled by the voltage applied between the conductive layer 311b and the conductive layer 313, so that the optical modulation of light can be controlled. That is, the intensity of light emitted through the substrate 560 can be controlled. Further, since light outside the specific wavelength region is absorbed by the color layer 131, the extracted light appears red, for example.

The light emitting element 360 is a bottom emission type light emitting element. The light-emitting element 360 has a stacked-layer structure in which the conductive layer 191 , the EL layer 192 , and the conductive layer 193 b are stacked in this order from the insulating layer 220 side. In addition, a conductive layer 193a covering the conductive layer 193b is provided. The conductive layer 193b contains a material that reflects visible light, and the conductive layer 191 and the conductive layer 193a contain a material that transmits visible light. The light emitted by the light emitting element 360 is emitted to the side of the substrate 560 through the color layer 134 , the insulating layer 220 , the opening 251 , the conductive layer 313 and the like.

Here, as shown in FIG. 22 , a conductive layer 311 a that transmits visible light is preferably provided in the opening 251 . Thereby, the liquid crystal 312 is aligned in the region overlapping the opening 251 in the same manner as the other regions, and it is possible to suppress unintended light leakage due to the misalignment of the liquid crystal occurring at the boundaries of these regions.

The thin film 13d on which the anti-glare pattern is formed is arranged on the outer surface of the substrate 560 . By using the thin film 13d formed with the anti-glare pattern, the reflected light can be scattered, whereby the display using the reflective display element can be easily seen. In addition, it may not be easily soiled by fingerprints or the like.

An insulating layer 217 is provided on the insulating layer 216 covering the end portion of the conductive layer 191 . The insulating layer 217 has a function of suppressing a spacer that is too close between the insulating layer 220 and the substrate 351 . In addition, when the EL layer 192 and the conductive layer 193a are formed using a shadow mask (metal mask), the insulating layer 217 can have a function of preventing the shadow mask from contacting the mask spacer on the surface to be formed. In addition, the insulating layer 217 may not be provided if not required.

One of the source electrode and the drain electrode of the transistor 205 is electrically connected to the conductive layer 191 of the light emitting element 360 through the conductive layer 224 .

The other one of the source electrode and the drain electrode of the transistor 206 is electrically connected to the conductive layer 311b through the connection portion 207 . The conductive layer 311a is in contact with the conductive layer 311b, and they are electrically connected to each other. The connection portion 207 is a portion that electrically connects the conductive layers provided on both sides of the insulating layer 220 to each other through openings formed in the insulating layer 220 .

The connection portion 204 is provided in a region of the substrate 351 that does not overlap with the substrate 560 . The connection portion 204 is electrically connected to the FPC 372 through the connection layer 242 . The connection portion 204 has the same structure as the connection portion 207 . On the top surface of the connection portion 204, a conductive layer obtained by processing the same conductive film as the conductive layer 311a is exposed. Therefore, the connection portion 204 can be electrically connected to the FPC 372 through the connection layer 242 .

The connecting portion 252 is provided in a region where a part of the adhesive layer 141 is provided. In the connection portion 252 , a conductive layer obtained by processing the same conductive film as the conductive layer 311 a and a part of the conductive layer 313 are electrically connected through the connector 243 . Thereby, the signal or potential input from the FPC 372 connected to the substrate 351 side can be supplied to the conductive layer 313 formed on the substrate 560 side through the connection portion 252 .

For example, conductive particles can be used as the connector 243 . As the conductive particles, particles of an organic resin, silica or the like whose surfaces are covered with a metal material can be used. As the metal material, nickel or gold is preferably used because it can reduce contact resistance. In addition, it is preferable to use particles in which two or more kinds of metal materials are coated in a layered form, for example, nickel is further coated with gold. In addition, the connector 243 is preferably made of a material capable of elastic deformation or plastic deformation. At this time, the connector 243 of the conductive particles may have a shape that is crushed in the longitudinal direction as shown in FIG. 22 . By having this shape, the contact area between the connector 243 and the conductive layer electrically connected to the connector can be increased, the contact resistance can be reduced, and the occurrence of problems such as poor contact can be suppressed.

The connector 243 is preferably configured to be covered by the adhesive layer 141 . For example, connectors 243 may be dispersed in adhesive layer 141 prior to curing.

In FIG. 22 , as an example of the circuit 364, an example in which the transistor 201 is provided is shown.

In FIG. 22, as an example of the transistor 201 and the transistor 205, a structure in which a semiconductor layer 231 forming a channel is sandwiched between two gate electrodes is applied. One gate is composed of the conductive layer 221 , and the other gate is composed of the conductive layer 223 overlapping the semiconductor layer 231 with the insulating layer 212 interposed therebetween. By adopting this structure, the threshold voltage of the transistor can be controlled. At this time, two gate electrodes may be connected, and the transistor may be driven by supplying the same signal to the two gate electrodes. Compared with other transistors, this transistor can improve the field efficiency mobility, and can increase the on-state current (on-state current). As a result, a circuit capable of high-speed driving can be manufactured. Furthermore, the occupied area of the circuit portion can be reduced. By using a transistor with a large on-state current, even if the number of wirings increases when the display panel is increased in size or high-definition, the signal delay of each wiring can be reduced, thereby suppressing display unevenness.

The transistor included in the circuit 364 and the transistor included in the display unit 362 may have the same structure. Additionally, the plurality of transistors included in circuit 364 may all have the same structure or different structures. In addition, the plurality of transistors included in the display portion 362 may all have the same structure or different structures.

At least one of the insulating layer 212 and the insulating layer 213 covering each transistor is preferably a material that does not easily diffuse impurities such as water or hydrogen. That is, the insulating layer 212 or the insulating layer 213 may be used as a barrier film. By adopting such a structure, the diffusion of impurities from the outside into the transistor can be effectively suppressed, so that a highly reliable display panel can be realized.

<4-5. Each component>

Next, each of the above-mentioned components will be described.

[substrate]

As the substrate included in the display panel, a material having a flat surface can be used. A material that transmits the light is used as the substrate on which the light from the display element is extracted. For example, materials such as glass, quartz, ceramics, sapphire, and organic resins can be used.

By using a thin substrate, the weight and thickness of the display panel can be reduced. Furthermore, by using a substrate whose thickness allows it to have flexibility, a flexible display panel can be realized.

The substrate on the side where the light emission is not extracted may not be light-transmitting, so a metal substrate or the like may be used in addition to the substrates exemplified above. Since the thermal conductivity of the metal substrate is high, it is easy to conduct heat to the entire substrate, so that the local temperature rise of the display panel can be suppressed, which is preferable. In order to obtain flexibility or bendability, the thickness of the metal substrate is preferably 10 μm or more and 200 μm or less, and more preferably 20 μm or more and 50 μm or less.

The material constituting the metal substrate is not particularly limited, and for example, metals such as aluminum, copper, and nickel, and alloys such as aluminum alloys and stainless steel are preferably used.

In addition, it is also possible to use a substrate that has undergone insulating treatment such as oxidizing the surface of the metal substrate or forming an insulating film on the surface. For example, the insulating film can be formed by a coating method such as a spin coating method or a dipping method, an electrodeposition method, a vapor deposition method, or a sputtering method. method to form an oxide film on the surface of the substrate.

As a material having flexibility and having permeability to visible light, for example, polyester resins such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), etc., Polyacrylonitrile resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyether (PES) resin, polyamide resin, cycloolefin resin, polystyrene resin, poly amide-imide resin, polyvinyl chloride resin or polytetrafluoroethylene (PTFE) resin, etc. In particular, it is preferable to use a material with a low thermal expansion coefficient, for example, polyamide-imide resin, polyimide resin, PET, etc. having a thermal expansion coefficient of 30×10 ^-6 /K or less are preferably used. In addition, a substrate in which glass fibers are impregnated with an organic resin, or a substrate in which the thermal expansion coefficient is lowered by mixing an inorganic filler with the organic resin can also be used. Since the substrate using this material is lightweight, the display panel using the substrate can also be reduced in weight.

When a fibrous body is contained in the above-mentioned material, a high-strength fiber of an organic compound or an inorganic compound is used as the fibrous body. Specifically, high-strength fibers refer to fibers having a high tensile modulus or Young's modulus. Typical examples thereof are polyvinyl alcohol-based fibers, polyester-based fibers, polyamide-based fibers, polyethylene-based fibers, aromatic polyamide-based fibers, polyparaphenylene benzobisazole fibers, glass fibers, or carbon fibers. As glass fiber, the glass fiber using E glass, S glass, D glass, Q glass, etc. is mentioned. The fiber body is used in the state of a woven fabric or a non-woven fabric, and a structure obtained by impregnating the fiber body with a resin and curing the resin can also be used as a flexible substrate. By using a structure composed of a fiber body and a resin as a flexible substrate, the reliability against breakage due to bending or local extrusion can be improved, which is preferable.

Alternatively, glass, metal, etc. thin enough to be flexible may be used for the substrate. Alternatively, a composite material in which glass and resin materials are bonded with an adhesive layer may be used.

A hard coat layer (for example, silicon nitride, aluminum oxide, etc.) to protect the surface of the display panel from damage, etc., and a layer of a material capable of dispersing pressing force (for example, aramid resin) can also be laminated on the flexible substrate. layer, etc.) etc. In addition, in order to suppress a reduction in the service life of the display element due to moisture or the like, an insulating film with low water permeability may be laminated on the flexible substrate. For example, inorganic insulating materials such as silicon nitride, silicon oxynitride, silicon oxynitride, aluminum oxide, and aluminum nitride can be used.

As a board|substrate, the board|substrate which laminated|stacked several layers can also be used. In particular, by adopting a structure having a glass layer, the barrier properties to water or oxygen can be improved, and a highly reliable display panel can be provided.

[transistor]

The transistor includes: a conductive layer serving as a gate electrode; a semiconductor layer; a conductive layer serving as a source electrode; a conductive layer serving as a drain electrode; and an insulating layer serving as a gate insulating layer. The case where a bottom gate structure transistor is used is shown above.

Note that the structure of the transistor included in the display device of one embodiment of the present invention is not particularly limited. For example, planar transistors, staggered transistors, or inverse staggered transistors may be used. In addition, top-gate or bottom-gate transistor structures may also be employed. Alternatively, gate electrodes may be provided above and below the channel.

The crystallinity of the semiconductor material used for the transistor is also not particularly limited, and an amorphous semiconductor or a semiconductor having crystallinity (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having a crystalline region in part thereof) can be used. When a semiconductor having crystallinity is used, deterioration of the characteristics of the transistor can be suppressed, which is preferable.

In addition, as a semiconductor material for a transistor, a metal oxide having an energy gap of 2 eV or more, preferably 2.5 eV or more, and more preferably 3 eV or more can be used. Typically, an oxide semiconductor or the like containing indium, such as CAC-OS described later, or the like can be used.

A transistor using an oxide semiconductor whose energy band gap is wider than silicon and has a smaller carrier density can retain charge stored in a capacitor element connected in series with the transistor for a long period of time because of its low off-state current.

As the semiconductor layer, for example, an oxide containing indium, zinc, and M (a metal such as aluminum, titanium, gallium, germanium, yttrium, zirconium, lanthanum, cerium, tin, neodymium, or hafnium) can be used, which is represented by "In-M-Zn-based oxide". film.

M及Zn

M。這種濺射靶材的金屬元素的原子個數比較佳為In：M：Zn=1：1：1、In：M：Zn=1：1：1.2、In：M：Zn=3：1：2、In：M：Zn=4：2：3、In：M：Zn=4：2：4.1、In：M：Zn=5：1：6、In：M：Zn=5：1：7、In：M：Zn=5：1：8等。注意，所形成的半導體層的原子個數比分別有可能在上述濺射靶材中的金屬元素的原子個數比的±40%的範圍內變動。 When the oxide semiconductor constituting the semiconductor layer is an In-M-Zn-based oxide, it is preferable that the atomic ratio of the metal element of the sputtering target for forming the In-M-Zn oxide film satisfies In

M and Zn

M. The atomic number of metal elements of this sputtering target is preferably In:M:Zn=1:1:1, In:M:Zn=1:1:1.2, In:M:Zn=3:1: 2. In:M:Zn=4:2:3, In:M:Zn=4:2:4.1, In:M:Zn=5:1:6, In:M:Zn=5:1:7, In:M:Zn=5:1:8, etc. Note that the atomic number ratio of the formed semiconductor layer may vary within a range of ±40% of the atomic number ratio of the metal element in the above-described sputtering target, respectively.

The transistor with the bottom gate structure shown in this embodiment is preferable because the manufacturing process can be reduced. In addition, by using an oxide semiconductor at this time, an oxide semiconductor can be formed at a temperature lower than that of polysilicon, and a material with low heat resistance can be used as the material of the wiring or electrode under the semiconductor layer, and the material of the substrate. range of materials. For example, a glass substrate having an extremely large area or the like can be appropriately used.

As the semiconductor layer, an oxide semiconductor film having a low carrier density can be used. For example, the carrier density that can be used as the semiconductor layer is 1×10 ¹⁷ /cm ³ or less, preferably 1×10 ¹⁵ /cm ³ or less, more preferably 1×10 ¹³ /cm ³ or less, and still more preferably 1× 10 ¹¹ /cm ³ or less, more preferably less than 1 × 10 ¹⁰ /cm ³ , and an oxide semiconductor of 1 × 10 ^-9 /cm ³ or more. Such an oxide semiconductor is referred to as a high-purity or substantially high-purity oxide semiconductor. Therefore, since the impurity concentration and the defect level density are low, it can be said that the oxide semiconductor has stable characteristics.

Note that the present invention is not limited to the above description, and a material having an appropriate composition can be used in accordance with desired semiconductor characteristics and electrical characteristics (field mobility, threshold voltage, etc.) of the transistor. In addition, it is preferable to appropriately set the carrier density, impurity concentration, defect density, atomic ratio of metal element and oxygen, interatomic distance, density, etc. of the semiconductor layer to obtain desired semiconductor characteristics of the transistor.

When the oxide semiconductor constituting the semiconductor layer contains silicon or carbon, which is one of the elements of Group 14, oxygen vacancies in the semiconductor layer increase, causing the semiconductor layer to become n-type. Therefore, the concentration of silicon or carbon in the semiconductor layer (concentration measured by secondary ion mass spectrometry) is set to 2×10 ¹⁸ atoms/cm ³ or less, preferably 2×10 ¹⁷ atoms/cm ³ or less .

In addition, when an alkali metal and an alkaline earth metal are bonded to an oxide semiconductor, a carrier may be generated, thereby increasing the off-state current of the transistor. Therefore, the concentration of the alkali metal or alkaline earth metal in the semiconductor layer measured by secondary ion mass spectrometry is set to 1×10 ¹⁸ atoms/cm ³ or less, preferably 2×10 ¹⁶ atoms/cm ³ or less.

In addition, when the oxide semiconductor constituting the semiconductor layer contains nitrogen, electrons are generated as carriers, the carrier density increases, and it becomes easy to become n-type. As a result, a transistor using a nitrogen-containing oxide semiconductor tends to have a normally-on characteristic. Therefore, the nitrogen concentration of the semiconductor layer measured by secondary ion mass spectrometry is preferably 5×10 ¹⁸ atoms/cm ³ or less.

In addition, the semiconductor layer may have, for example, a non-single crystal structure. The non-single crystal structure includes, for example, a crystalline CAAC-OS (C-Axis Aligned Crystalline Oxide Semi conductor) having a c-axis alignment, a polycrystalline structure, a microcrystalline structure or an amorphous structure. Among the non-single-crystal structures, the amorphous structure has the highest density of defect states, while that of CAAC-OS is the lowest.

An oxide semiconductor film of an amorphous structure has, for example, a disordered atomic arrangement and no crystalline component. Alternatively, the oxide film of the amorphous structure has, for example, a completely amorphous structure and does not have a crystal part.

In addition, the semiconductor layer may be a mixed film of two or more of an amorphous structure region, a microcrystalline structure region, a polycrystalline structure region, a CAAC-OS region, and a single crystal structure region. The hybrid film may have, for example, a single-layer structure or a stacked-layer structure including two or more of the above-mentioned regions.

[Constitution of CAC-OS]

The following describes the details of the metal oxide having a CAC structure that can be used in the semiconductor layer of the transistor disclosed in one embodiment of the present invention. Here, CAC-OS will be used as a typical example of a metal oxide having a CAC structure.

For example, as in the structure formed on the insulating film 106 shown in FIG. 23 , the elements contained in the metal oxide in CAC-OS are unevenly distributed, and the regions 101 and 102 containing each element as a main component are mixed to form Formed or dispersed as mosaics. In other words, CAC-OS is a structure in which the elements contained in the metal oxide are unevenly distributed, and the size of the material containing the unevenly distributed elements is 0.5 nm or more and 10 nm or less, preferably 0.5 nm or more and 3 nm or less. or approximate size.

The physical properties of a region containing a specific element that is unevenly distributed are determined by the properties of the element. For example, a region containing an element that is more likely to be an insulator among elements contained in a metal oxide that is unevenly distributed becomes a dielectric region. On the other hand, a region including an element that is more likely to be a conductor among the elements included in the metal oxide that is unevenly distributed becomes a conductor region. When conductive regions and dielectric regions are mixed in a mosaic, the material functions as a semiconductor.

In other words, the metal oxide in one embodiment of the present invention is one of a matrix composite or a metal matrix composite in which materials having different physical properties are mixed.

The oxide semiconductor preferably contains at least indium. It is especially preferable to contain indium and zinc. In addition, it can also contain elements M (M is selected from gallium, aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, one or more of hafnium, tantalum, tungsten, and magnesium, etc.).

For example, CAC-OS in In-Ga-Zn oxide (in CAC-OS, In-Ga-Zn oxide can especially be referred to as CAC-IGZO) means that the material is divided into indium oxide (hereinafter, referred to as InO _X1 (X1 is a real number greater than 0)) or indium zinc oxide (hereinafter referred to as In _X2 Zn _Y2 O _Z2 (X2, Y2 and Z2 are real numbers greater than 0)) and gallium oxide (hereinafter referred to as GaO _X3 (X3 is a real number greater than 0)) or gallium zinc oxide (hereinafter, referred to as Ga _X4 Zn _Y4 O _Z4 (X4, Y4 and Z4 are real numbers greater than 0)), etc. to form a mosaic, and mosaic-like InO _X1 Or a structure in which In _X2 Zn _Y2 O _Z2 is uniformly distributed in the film (hereinafter, also referred to as cloud shape).

In other words, CAC-OS is a composite oxide semiconductor having a structure in which a region mainly composed of GaO _X3 and a region mainly composed of In _X2 Zn _Y2 O _Z2 or InO _X1 are mixed together. In this specification, for example, when the atomic number ratio of In to the element M in the first region is larger than the atomic ratio of In to the element M in the second region, the In concentration of the first region is higher than that of the second region.

x0

1，m0為任意數)表示的結晶性化合物。 Note that IGZO is a generic term and may refer to a compound containing In, Ga, Zn, and O. Typical examples include InGaO ₃ (ZnO) _m1 (m1 is a natural number) or In _(1+x0) Ga _(1-x0) O ₃ (ZnO) _m0 (-1

x0

1, m0 is a crystalline compound represented by an arbitrary number).

The above-mentioned crystalline compound has a single crystal structure, a polycrystalline structure or a CAAC structure. The CAAC structure is a crystalline structure in which a plurality of IGZO nanocrystals have c-axis alignment and are connected in a non-aligned manner on the a-b planes.

On the other hand, CAC-OS is related to the material composition of oxide semiconductors. CAC-OS refers to a structure in which, in a material structure including In, Ga, Zn, and O, a nanoparticle-like region mainly composed of Ga is observed in a part, and a nanoparticle region mainly composed of In is observed in a part. particle-like regions, and these regions are randomly dispersed in a mosaic shape. Therefore, in CAC-OS, the crystalline structure is a secondary factor.

CAC-OS does not include a stacked structure of two or more films with different compositions. For example, a structure composed of two layers of a film containing In as a main component and a film containing Ga as a main component is not included.

Note that a clear boundary between the region mainly composed of GaO _X3 and the region mainly composed of In _X2 Zn _Y2 O _Z2 or InO _X1 may not be observed.

In the CAC-OS, a compound selected from the group consisting of aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten and magnesium is included. In the case where one or more kinds of gallium are used instead of gallium, CAC-OS refers to a structure in which a nanoparticle-like region mainly composed of this element is observed in a part, and a nanoparticle-shaped region mainly composed of In is observed in a part. , and these regions are scattered irregularly in a mosaic pattern.

[Analysis of CAC-OS]

Next, the measurement results of the oxide semiconductor formed on the substrate using various measurement methods will be described.

[Sample structure and manufacturing method]

Hereinafter, nine samples of one embodiment of the present invention will be described. The substrate temperature and the oxygen gas flow rate ratio at the time of forming the oxide semiconductor were different between the samples. Each sample includes a substrate and an oxide semiconductor on the substrate.

The manufacturing method of each sample is demonstrated.

A glass substrate was used as the substrate. An In-Ga-Zn oxide having a thickness of 100 nm was formed on a glass substrate as an oxide semiconductor using a sputtering apparatus. The film formation conditions were as follows: the pressure in the processing chamber was set to 0.6 Pa, and an oxide target (In:Ga:Zn=4:2:4.1 [atomic number ratio]) was used as the target. In addition, AC power of 2500 W was supplied to the oxide target set in the sputtering apparatus.

Nine samples were produced under the following conditions when forming oxides: the substrate temperature was set to a temperature (hereinafter, also referred to as room temperature or R.T.) without intentional heating, 130°C or 170°C. In addition, the flow ratio of the oxygen gas to the mixed gas of Ar and oxygen (hereinafter, also referred to as the oxygen gas flow ratio) is set to 10%, 30%, or 100%.

[X-ray diffraction analysis]

In this section, the results of X-ray diffraction (XRD: X-ray diffraction) measurement on nine samples are described. As the XRD apparatus, D8 ADVANCE manufactured by Bruker was used. The measurement conditions were as follows: θ/2θ scanning was performed by the Out-of-plane method, the scanning range was 15 deg. to 50 deg., the step width was 0.02 deg., and the scanning speed was 3.0 deg./min.

FIG. 24 shows the results of measuring the XRD spectrum by the Out-of-plane method. In FIG. 24 , the top row shows the measurement result of the sample whose substrate temperature during film formation was 170° C., the middle row shows the measurement result of the sample whose substrate temperature during film formation was 130° C., and the bottom row shows the measurement result of film formation. The substrate temperature of R.T. was measured for samples. In addition, the leftmost column shows the measurement result of the sample whose oxygen gas flow ratio is 10%, the middle column shows the measurement result of the sample whose oxygen gas flow ratio is 30%, and the rightmost column shows the measurement result of the sample whose oxygen gas flow ratio is 100%. sample measurement results.

In the XRD spectrum shown in FIG. 24 , the higher the substrate temperature during film formation or the higher the oxygen gas flow rate ratio during film formation, the greater the peak intensity around 2θ=31°. In addition, it is known that the peak around 2θ=31° is derived from a crystalline IGZO compound (also referred to as CAAC (c-axis aligned crystalline)-IGZO) having c-axis alignment in the direction substantially perpendicular to the surface to be formed or the top surface. ).

In addition, as shown in the XRD spectrum of FIG. 24 , the lower the substrate temperature during film formation or the lower the oxygen gas flow rate ratio, the less pronounced the peak. Therefore, it was found that the alignment in the a-b plane direction and the c-axis direction of the measurement region was not observed in the samples in which the substrate temperature during film formation was low or the oxygen gas flow rate ratio was low.

[Electron Microscopic Analysis]

In this section, the use of HAADF-STEM (High-Angle Annular Dark Field Scanning Transmission Electron Microscope: High-Angle Annular Dark Field Scanning Transmission Electron Microscope: High-Angle Annular Dark Field Scanning Transmission Electron Microscope: High-Angle Annular Dark Field) for samples fabricated under the conditions of R.T. - Scanning Transmission Electron Microscope) observation and analysis results (hereinafter, the image acquired by HAADF-STEM is also referred to as a TEM image).

The result of image analysis of the plane image (hereinafter, also referred to as plane TEM image) and the cross-section image (hereinafter, also referred to as cross-section TEM image) acquired by HAADF-STEM will be described. TEM images were observed with spherical aberration correction. When the HAADF-STEM image was acquired, an atomic resolution analysis electron microscope JEM-ARM200F manufactured by JEOL Ltd. was used, the acceleration voltage was set to 200 kV, and an electron beam having a beam diameter of approximately 0.1 nmΦ was irradiated.

25A is a planar TEM image of a sample fabricated under the conditions that the substrate temperature during film formation is R.T. and the oxygen gas flow ratio is 10%. 25B is a cross-sectional TEM image of a sample fabricated under the conditions that the substrate temperature during film formation is R.T. and the oxygen gas flow ratio is 10%.

[Analysis of Electron Diffraction Pattern]

In this section, it is explained that the sample obtained by irradiating an electron beam (also referred to as a nanobeam) with a beam diameter of 1 nm to a sample produced under the conditions that the substrate temperature at the time of film formation is R.T. and the oxygen gas flow ratio is 10%, is obtained. Results of the electron diffraction pattern.

Observe the black point a1, black point a2, black point a3, and black point a4 in the planar TEM image of the sample produced under the conditions of the substrate temperature at the time of film formation being R.T. and the oxygen gas flow ratio of 10% shown in FIG. 25A and the electron diffraction pattern of black point a5. The electron diffraction pattern was observed by irradiating the electron beam at a constant speed for 35 seconds. Fig. 25C shows the result for black point a1, Fig. 25D shows the result for black point a2, Fig. 25E shows the result for black point a3, Fig. 25F shows the result for black point a4, and Fig. 25G shows the result for black point a5.

In FIGS. 25C , 25D, 25E, 25F, and 25G, regions with high brightness such as circles (ring-shaped) are observed. In addition, multiple spots were observed in the annular region.

Observe the black point b1, black point b2, black point b3, black point b4 in the cross-sectional TEM image of the sample produced under the condition that the substrate temperature during film formation is R.T. and the oxygen gas flow ratio is 10% as shown in FIG. 25B and the electron diffraction pattern of black dot b5. Figure 25H shows the result for black point b1, Figure 25I shows the result for black point b2, Figure 25J shows the result for black point b3, Figure 25K shows the result for black point b4, and Figure 25L shows the result for black point b5.

In FIGS. 25H , 25I, 25J, 25K, and 25L, a ring-shaped region with high brightness was observed. In addition, multiple spots were observed in the annular region.

For example, when an electron beam with a beam diameter of 300 nm is incident _on a CAAC _- OS containing InGaZnO crystals in a direction parallel to the sample surface, a diffraction pattern containing spots originating from the (009) plane of the InGaZnO crystals can be obtained. In other words, the CAAC-OS has a c-axis orientation, and the c-axis is oriented in a direction substantially perpendicular to the surface to be formed or the top surface. On the other hand, when an electron beam having a beam diameter of 300 nm was incident on the same sample in a direction perpendicular to the sample surface, a circular diffraction pattern was observed. In other words, CAAC-OS does not have a-axis alignment and b-axis alignment.

When electron diffraction of a nanocrystalline oxide semiconductor (hereinafter referred to as nc-OS) with microcrystals is performed using an electron beam with a large beam diameter (eg, 50 nm or more), a diffraction pattern similar to a halo pattern is observed . In addition, when nc-OS was subjected to nanobeam electron diffraction using an electron beam with a small beam diameter (eg, less than 50 nm), bright spots (spots) were observed. In addition, in the nanobeam electron diffraction pattern of nc-OS, a region with high brightness such as a circle (ring-shaped) may be observed. Also, a plurality of bright spots are sometimes observed in the annular region.

The electron diffraction pattern of the sample produced under the conditions that the substrate temperature during film formation was R.T. and the oxygen gas flow ratio was 10% had a ring-shaped region with high brightness and many bright spots appeared in the ring-shaped region. Therefore, the samples fabricated under the conditions of the substrate temperature at the time of film formation being R.T. and the oxygen gas flow ratio being 10% exhibited electron diffraction patterns similar to those of nc-OS, and had no alignment in the plane and cross-section directions.

As described above, the properties of an oxide semiconductor having a low substrate temperature or a low oxygen gas flow ratio during film formation are significantly different from those of an oxide semiconductor film of an amorphous structure and an oxide semiconductor film of a single crystal structure.

[Elemental analysis]

In this section, it is explained that the EDX surface analysis image is obtained and evaluated using energy dispersive X-ray spectroscopy (EDX), and the substrate temperature at the time of film formation is R.T. and the oxygen gas flow ratio is Results of elemental analysis of samples fabricated under 10% conditions. In the EDX measurement, an energy dispersive X-ray analyzer JED-2300T manufactured by JEOL Ltd. was used as an elemental analyzer. In detecting the X-rays emitted from the sample, a silicon drift detector is used.

In EDX measurement, an electron beam is irradiated to each point in the analysis target region of a sample, the energy and the number of occurrences of characteristic X-rays of the sample generated at this time are measured, and an EDX spectrum corresponding to each point is obtained. In this embodiment, the peak of the EDX spectrum at each point is attributed to the electronic transition to the L shell in the In atom, the electronic transition to the K shell in the Ga atom, and the electronic transition to the K shell in the Zn atom. and the electron transition to the K shell in the O atom, and the ratio of each atom at each point was calculated. By performing the above steps in the analysis target region of the sample, an EDX surface analysis image showing the ratio distribution of each atom can be obtained.

FIGS. 26A to 26C show EDX surface analysis images of cross-sections of samples manufactured under the conditions that the substrate temperature at the time of film formation is R.T. and the oxygen gas flow rate ratio is 10%. FIG. 26A shows an EDX surface analysis image of Ga atoms (the ratio occupied by Ga atoms in all atoms is 1.18 to 18.64 [atomic %]). FIG. 26B shows an EDX surface analysis image of In atoms (the ratio occupied by In atoms in all atoms is 9.28 to 33.74 [atomic %]). FIG. 26C shows an EDX surface analysis image of Zn atoms (the ratio occupied by Zn atoms in all atoms is 6.69 to 24.99 [atomic %]). 26A , 26B and 26C show the same regions in the cross-sections of the samples manufactured under the conditions that the substrate temperature during film formation is R.T. and the oxygen gas flow rate ratio is 10%. In the EDX surface analysis image, the ratio of elements is represented by light and dark: the more measured elements in the area, the brighter the area, and the less measured elements, the darker the area. The magnification of the EDX plane analysis images shown in FIGS. 26A to 26C is 7.2 million times.

In the EDX surface analysis images shown in FIGS. 26A , 26B, and 26C, the relative distribution of light and dark was confirmed, and it was confirmed in the samples manufactured under the conditions that the substrate temperature at the time of film formation was R.T. and the oxygen gas flow ratio was 10%. to each atom has a distribution. Here, attention will be paid to the area surrounded by the solid line and the area surrounded by the broken line shown in FIGS. 26A , 26B and 26C .

In FIG. 26A , there are many relatively dark areas in the area surrounded by solid lines, and many relatively bright areas in the area surrounded by dotted lines. In addition, in FIG. 26B , there are many relatively bright areas in the area surrounded by the solid line, and many relatively dark areas in the area surrounded by the dotted line.

In other words, the region surrounded by the solid line is a region with relatively many In atoms, and the region surrounded by the dotted line is a region with relatively few In atoms. In FIG. 26C, within the area surrounded by the solid line, the right side is a relatively bright area, and the left side is a relatively dark area. Therefore, the region surrounded by the solid line is a region mainly composed of In _X2 Zn _Y2 O _Z2 , InO _X1 , or the like.

In addition, the region surrounded by the solid line is a region with relatively few Ga atoms, and the region surrounded by the broken line is a region with relatively many Ga atoms. In FIG. 26C, within the area surrounded by the dotted line, the upper left area is a relatively bright area, and the lower right area is a relatively dark area. Therefore, the region surrounded by the dotted line is a region mainly composed of GaO _X3 , Ga _X4 Zn _Y4 O _Z4 , or the like.

As shown in FIGS. 26A , 26B and 26C , the distribution of In atoms is more uniform than the distribution of Ga atoms, and the region containing InO _X1 as the main component appears to be formed by using In _X2 Zn _Y2 O _Z2 as the main component areas are interconnected. In this way, a region mainly composed of In _X2 Zn _Y2 O _Z2 or InO _X1 is formed in a cloud-like manner.

In this way, an In-Ga-Zn oxide having a structure in which a region containing GaO _X3 or the like as a main component and a region containing In _X2 Zn _Y2 O _Z2 or InO _X1 as a main component are unevenly distributed and mixed can be referred to as CAC- OS.

The crystal structure of CAC-OS has an nc structure. In the electron diffraction pattern of CAC ^- OS having an nc structure, a plurality of bright spots (spots) appeared in addition to the bright spots (spots) due to IGZO including single crystal, polycrystalline or CAAC structure. Alternatively, the crystal structure is defined as the appearance of a ring-shaped region with high brightness in addition to the appearance of a plurality of bright spots (spots).

In addition, as shown in FIGS. 26A , 26B and 26C , the size of the region mainly composed of GaO _X3 and the like and the region mainly composed of In _X2 Zn _Y2 O _Z2 or InO _X1 is 0.5 nm or more and 10 nm or less, or 1 nm. more than 3 nm or less. In the EDX surface analysis image, the diameter of the region containing each element as a main component is preferably 1 nm or more and 2 nm or less.

As described above, the structure of CAC-OS is different from IGZO compounds in which metal elements are uniformly distributed, and it has different properties from IGZO compounds. In other words, the CAC-OS has a mosaic-like structure in which the region mainly composed of GaO _X3 and the like and the region mainly composed of In _X2 Zn _Y2 O _Z2 or InO _X1 are separated from each other and the region mainly composed of each element is formed.

Here, the conductivity of the region mainly composed of In _X2 Zn _Y2 O _Z2 or InO _X1 is higher than that of the region mainly composed of GaO _X3 or the like. In other words, when carriers flow through the region mainly composed of In _X2 Zn _Y2 O _Z2 or InO _X1 , the conductivity of an oxide semiconductor is exhibited. Therefore, when a region mainly composed of In _X2 Zn _Y2 O _Z2 or InO _X1 is distributed in a cloud shape in the oxide semiconductor, a high field efficiency mobility (μ) can be achieved.

On the other hand, the insulating property of the region mainly composed of GaO _X3 or the like is higher than that of the region mainly composed of In _X2 Zn _Y2 O _Z2 or InO _X1 . In other words, when a region mainly composed of GaO _X3 or the like is distributed in the oxide semiconductor, leakage current can be suppressed and a good switching operation can be realized.

Therefore, when CAC-OS is used for a semiconductor element, a high on-state current (I _on ) can be realized by the complementary effect of the insulating properties due to GaO _X3 and the like and the conductivity due to In _X2 Zn _Y2 O _Z2 or InO _X1 and high field mobility (μ).

In addition, semiconductor elements using CAC-OS have high reliability. Therefore, CAC-OS is suitable for various semiconductor devices such as displays.

Alternatively, silicon can be used for the semiconductor forming the channel of the transistor. Amorphous silicon can be used as silicon, and it is particularly preferable to use silicon having crystallinity. For example, it is preferable to use microcrystalline silicon, polycrystalline silicon, monocrystalline silicon, or the like. In particular, polycrystalline silicon can be formed at a lower temperature than monocrystalline silicon, and its field efficiency mobility is higher than that of amorphous silicon, so polycrystalline silicon has high reliability.

The transistor with the bottom gate structure exemplified in this embodiment is preferable because the manufacturing process can be reduced. In addition, by using amorphous silicon at this time, it can be formed at a lower temperature than polysilicon. Therefore, materials with low heat resistance can be used as materials for wirings and electrodes under the semiconductor layer, and materials for substrates. range of materials. For example, a very large area glass substrate or the like can be appropriately used. On the other hand, the top gate transistor is preferable because it is easy to form impurity regions in a self-aligned manner and can reduce unevenness in characteristics and the like. In this case, it is particularly preferable to use polycrystalline silicon, single crystal silicon, or the like.

[Conductive layer]

Examples of materials that can be used for conductive layers such as gates, sources, and drains of transistors and various wirings and electrodes constituting display devices include aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, Metals such as tantalum and tungsten, or alloys containing these metals as their main components, etc. In addition, films comprising these materials can be used in a single layer or in a laminated structure. For example, a single-layer structure of an aluminum film containing silicon, a two-layer structure of an aluminum film laminated on a titanium film, a two-layer structure of an aluminum film laminated on a tungsten film, and a copper-magnesium-aluminum alloy film laminated with copper can be mentioned. Two-layer structure of film, two-layer structure of copper film laminated on titanium film, two-layer structure of copper film laminated on tungsten film, sequential lamination of titanium film or titanium nitride film, aluminum film or copper film, and titanium film or nitrogen film A three-layer structure of a titanium oxide film, and a three-layer structure of 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 sequentially laminated. In addition, oxides such as indium oxide, tin oxide, or zinc oxide can be used. Moreover, since the controllability of the shape at the time of etching can be improved by using copper containing manganese, it is preferable.

Further, as the light-transmitting conductive material, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and gallium-added zinc oxide, or graphene can be used. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, and alloy materials containing the metal materials can be used. Alternatively, a nitride (eg, titanium nitride) or the like of the metal material may also be used. In addition, when a metal material or an alloy material (or their nitrides) is used, it may be thin enough to have translucency. In addition, a laminated film of the above-mentioned materials can be used as the conductive layer. For example, by using an alloy of silver and magnesium and a laminated film of indium tin oxide, etc., the conductivity can be improved, which is preferable. The above-mentioned materials can also be used for conductive layers constituting various wirings and electrodes of display devices, and conductive layers included in display elements (conductive layers used as pixel electrodes or common electrodes).

[Insulation]

As insulating materials that can be used for each insulating layer, for example, resins such as acrylic resins or epoxy resins, resins having siloxane bonds, inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon oxynitride, silicon nitride or the like can be used. Alumina etc.

In addition, the light-emitting element is preferably provided between a pair of insulating films with low water permeability. Thereby, it is possible to prevent impurities such as water from entering the light-emitting element, and it is possible to prevent the reliability of the device from deteriorating.

Examples of insulating films with low water permeability include films containing nitrogen and silicon such as silicon nitride films and silicon oxynitride films, films containing nitrogen and aluminum such as aluminum nitride films, and the like. In addition, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, or the like can also be used.

For example, the water vapor transmission amount of the insulating film with low water permeability is 1×10 ^-5 [g/(m ² ·day)] or less, preferably 1×10 ^-6 [g/(m ² ·day)] or less , more preferably 1×10 ⁻⁷ [g/(m ² ·day)] or less, and still more preferably 1×10 ⁻⁸ [g/(m ² ·day)] or less.

[liquid crystal element]

As the liquid crystal element, a liquid crystal element using a VA (Vertical Alignment: Vertical Alignment) mode can be used. As the vertical alignment mode, an MVA (Multi-Domain Vertical Alignment) mode, a PVA (Patterned Vertical Alignment) mode, an ASV (Advanced Super View) mode, or the like can be used.

Moreover, as a liquid crystal element, the liquid crystal element using various modes can be employ|adopted. For example, in addition to the VA mode, TN (Twisted Nematic: Twisted Nematic) mode, IPS (In-Plane-Switching: In-Plane Switching) mode, FFS (Fringe Field Switching: Fringe Field Switching) mode; ASM (Axially Symmetric Aligned) mode can be used Micro-cell: Axisymmetric arrangement of micro cells) mode, OCB (Optically Compensated Birefringence: Optical Compensation Bend) mode, FLC (Ferroelectric Liquid Crystal: Ferroelectric Liquid Crystal) mode, AFLC (AntiFerroelectric Liquid Crystal: Antiferroelectric Liquid Crystal) mode, etc. of liquid crystal elements.

The liquid crystal element is an element that controls the transmission or non-transmission of light by utilizing the optical modulation effect of liquid crystal. The optical modulation of the liquid crystal is controlled by the electric field (including the transverse electric field, the longitudinal electric field or the oblique direction electric field) applied to the liquid crystal. As the liquid crystal used in the liquid crystal element, thermotropic liquid crystal, low molecular liquid crystal, polymer liquid crystal, polymer dispersed liquid crystal (PDLC: Polymer Dispersed Liquid Crystal), ferroelectric liquid crystal, antiferroelectric liquid crystal and the like can be used. These liquid crystal materials exhibit a cholesteric phase, a smectic phase, a cubic phase, a chiral nematic phase, and an isotropic phase, depending on conditions.

In addition, as the liquid crystal material, either positive type liquid crystal or negative type liquid crystal can be used, and an appropriate liquid crystal material may be used according to the mode or design to be used.

In addition, in order to control the alignment of the liquid crystal, an alignment film may be provided. In the case of using the transverse electric field method, a liquid crystal exhibiting a blue phase without using an alignment film can also be used. The blue phase is a type of liquid crystal phase, and refers to a phase that appears just before the transition from the cholesteric phase to the homogeneous phase when the temperature of the cholesteric liquid crystal is raised. Since the blue phase appears only in a narrow temperature range, a liquid crystal composition in which a chiral agent of several wt % or more is mixed is used for the liquid crystal layer to widen the temperature range. A liquid crystal composition comprising a liquid crystal exhibiting a blue phase and a chiral agent has a high response speed and is optically isotropic. In addition, a liquid crystal composition containing a liquid crystal exhibiting a blue phase and a chiral agent does not require alignment treatment and has little viewing angle dependence. In addition, since there is no need to provide an alignment film and no rubbing treatment is required, electrostatic damage caused by the rubbing treatment can be prevented, and defects and breakage of the liquid crystal display device during the manufacturing process can be reduced.

In addition, as the liquid crystal element, a transmissive liquid crystal element, a reflective liquid crystal element, a semi-transmissive liquid crystal element, or the like can be used.

In one embodiment of the present invention, a reflective liquid crystal element can be used in particular.

When a transmissive liquid crystal element or a semi-transmissive liquid crystal element is used, two polarizing plates are provided so as to sandwich a pair of substrates. In addition, a backlight is provided on the outside of one polarizing plate. The backlight can be a direct type backlight or an edge-lit type backlight. When a direct type backlight including LEDs is used, local dimming can be easily performed, whereby the contrast ratio can be improved, which is preferable. In addition, when an edge lighting type backlight is used, the module including the backlight can be formed thinner, which is preferable.

When a reflective liquid crystal element is used, the polarizing plate is provided on the display surface side. In addition, when a light-diffusion plate is provided on the display surface side, visibility can be improved, which is preferable.

In addition, when a reflective or semi-transmissive liquid crystal element is used, a front light source may be provided outside the polarizing plate. As the front light source, it is preferable to use an edge lighting type front light source. When a front light source with LEDs is used, power consumption can be reduced, so it is preferable.

In one embodiment of the present invention, it is especially preferred that the liquid crystal material contains a dichroic dye. Also, liquid crystal materials containing dichroic dyes are called guest-host liquid crystals. Specifically, in the guest-host liquid crystal, a material having a large absorbance in the long axis direction of the molecule and a small absorbance in the short axis direction orthogonal to the long axis direction can be used as a dichroic dye. Preferably, a material having a dichroic ratio of 10 or more is used as the dichroic dye, and more preferably, a material having a dichroic ratio of 20 or more is used as the dichroic dye.

For example, azo-based dyes, anthraquinone-based dyes, dioxazine-based dyes, and the like can be used as the dichroic dyes. Alternatively, a structure in which two liquid crystal layers containing parallel-aligned dichroic dyes are overlapped so that the alignment directions are orthogonal to each other may be used for the layer containing the liquid crystal material. Thereby, omnidirectional light can be easily absorbed. Alternatively, the contrast ratio can be increased.

In addition, a phase-transition-type guest-host liquid crystal or a droplet containing the guest-host liquid crystal may be dispersed in a polymer structure for use as a liquid crystal material.

Here, the structure in which the liquid crystal material of the liquid crystal element contains the dichroic dye will be described with reference to FIGS. 27A and 27B .

27A and 27B are diagrams for explaining the operation of the liquid crystal element 780 according to the embodiment of the present invention.

The liquid crystal element 780 shown in FIGS. 27A and 27B includes a liquid crystal layer 783 and alignment films 785a and 785b between a pair of electrodes (an electrode 781 and an electrode 782). In addition, the liquid crystal layer 783 includes a liquid crystal material LC and a dichroic dye DD. In addition, here, the electrode 781 is demonstrated as a reflective electrode, and the electrode 782 is demonstrated as a translucent electrode.

FIG. 27A is a diagram illustrating an operating state of the liquid crystal layer 783, and FIG. 27B is a diagram illustrating an operating state different from that in FIG. 27A.

As shown in FIG. 27A , the dichroic dye DD is aligned in such a way as to absorb less light traveling in the thickness direction. For example, an electric field is used to align a liquid crystal material LC serving as a host material, and control the alignment of a dichroic dye serving as a guest material. Thereby, the transmitted light can be reflected by the electrode 781 . Therefore, a reflective liquid crystal element can be formed without using a polarizing plate.

Further, when the hybrid display described above is assumed, a light-emitting element is provided below the liquid crystal element 780 . When this structure is adopted, the attenuation of the light emitted from the light-emitting element can be suppressed by aligning so that the absorption of the dichroic dye DD is less. Therefore, since the light emitted by the light emitting element is not blocked by the polarizing plate or the like, the light emitted by the light emitting element can be efficiently used.

Further, as shown in FIG. 27B , the dichroic dye DD is aligned so as to absorb more light traveling in the thickness direction. For example, an electric field is used to align a liquid crystal material LC serving as a host material, and control the alignment of a dichroic dye serving as a guest material. Thereby, the transmitted light is absorbed by the dichroic dye DD, and the light incident on the electrode 781 can be weakened. Therefore, a reflective liquid crystal element can be formed without using a polarizing plate.

[Light-emitting element]

As the light-emitting element, an element capable of self-luminescence can be used, and an element whose luminance is controlled by current or voltage is included in its category. For example, LEDs, organic EL elements, inorganic EL elements, and the like can be used.

The structure of the light-emitting element includes a top emission structure, a bottom emission structure, a double-sided emission structure, and the like. A conductive film that transmits visible light is used as the electrode on the light extraction side. In addition, it is preferable to use a conductive film that reflects visible light as the electrode on the side that does not extract light.

The EL layer includes at least a light-emitting layer. As layers other than the light-emitting layer, the EL layer may further contain a substance with high hole injecting property, a substance with high hole transport property, a hole blocking material, a substance with high electron transport property, a substance with high electron injecting property, or bipolar layer of a substance (a substance with high electron-transporting properties and hole-transporting properties), etc.

The EL layer may use a low molecular compound or a high molecular compound, and may also contain an inorganic compound. The layers constituting the EL layer can be formed by methods such as vapor deposition methods (including vacuum vapor deposition methods), transfer methods, printing methods, ink jet methods, and coating methods, respectively.

When a voltage higher than the critical voltage of the light-emitting element is applied between the cathode and the anode, holes are injected into the EL layer from the anode side, and electrons are injected into the EL layer from the cathode side. The injected electrons and holes are recombined in the EL layer, whereby the light-emitting substance contained in the EL layer emits light.

When a light-emitting element that emits white light is used as the light-emitting element, it is preferable that the EL layer contains two or more kinds of light-emitting substances. For example, white light emission can be obtained by selecting a light-emitting substance so that the respective light emission of two or more light-emitting substances is in a complementary color relationship. For example, it is preferable to include two or more of the following light-emitting substances: a light-emitting substance that emits light such as R (red), G (green), B (blue), Y (yellow), and O (orange), and a light-emitting substance that emits light including R A luminescent substance that emits light with spectral components of two or more colors in G and B. In addition, it is preferable to use a light-emitting element having two or more peaks in the wavelength range of the visible light region (eg, 350 nm to 750 nm) in the spectrum of light emission from the light-emitting element. In addition, the emission spectrum of the material having a peak in the wavelength range of yellow preferably also has spectral components in the wavelength range of green and red.

The EL layer preferably adopts a laminated structure including a light-emitting layer including a light-emitting material emitting light of one color and a light-emitting layer including a light-emitting material emitting light of another color. For example, a plurality of light-emitting layers in the EL layer may be stacked in contact with each other, or may be stacked with a region not containing any light-emitting material interposed therebetween. For example, a region containing the same material (eg, host material, auxiliary material) as the fluorescent light-emitting layer or the phosphorescent light-emitting layer and not containing any light-emitting material may be provided between the fluorescent light-emitting layer and the phosphorescent light-emitting layer. This facilitates the manufacture of the light-emitting element, and further reduces the driving voltage.

In addition, the light-emitting element may be a single element including one EL layer, or may be a tandem element in which a plurality of EL layers are stacked with a charge generating layer interposed therebetween.

As a conductive film which transmits visible light, it can be formed using, for example, indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, gallium-added zinc oxide, or the like. In addition, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium or titanium, alloys containing these metal materials, or nitrides ( For example, titanium nitride) or the like is formed thin enough to have light transmittance and is used. In addition, a laminated film of the above-mentioned materials can be used as the conductive layer. For example, it is preferable to use a laminated film of an alloy of silver and magnesium and indium tin oxide, etc., since the conductivity can be improved. In addition, graphene or the like can also be used.

As the conductive film reflecting visible light, for example, metal materials such as aluminum, gold, platinum, silver, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium, or alloys containing these metal materials can be used. In addition, lanthanum, neodymium, germanium, or the like may be added to the above-mentioned metal material or alloy. In addition, an alloy (aluminum alloy) containing titanium, nickel or neodymium and aluminum can also be used. In addition, alloys containing copper, palladium, magnesium, and silver may also be used. Alloys containing silver and copper are preferred because of their high heat resistance. Furthermore, by stacking the metal film or the metal oxide film in contact with the aluminum film or the aluminum alloy film, oxidation can be suppressed. As a material of such a metal film and a metal oxide film, titanium, titanium oxide, etc. are mentioned. In addition, the above-mentioned conductive film that transmits visible light and a film made of a metal material may be laminated. For example, a laminated film of silver and indium tin oxide, a laminated film of an alloy of silver and magnesium and indium tin oxide, or the like can be used.

Each electrode can be formed by a vapor deposition method or a sputtering method. In addition to this, each electrode may be formed by a discharge method such as an inkjet method, a printing method such as a screen printing method, or a plating method.

In addition, the above-mentioned light-emitting layer and the layer containing a material with high hole injecting properties, a material with high hole transporting property, a material with high electron transporting property, a material with high electron injecting property, a bipolar material, etc. may respectively contain quantum dots or the like. Inorganic compounds or high molecular compounds (oligomers, dendrimers or polymers, etc.). For example, by using quantum dots for a light-emitting layer, it can also be used as a light-emitting material.

As the quantum dot material, a colloidal quantum dot material, an alloy type quantum dot material, a core shell type quantum dot material, a core type quantum dot material and the like can be used. In addition, materials including element groups of Groups 12 and 16, Groups 13 and 15, and Groups 14 and 16 can also be used. Alternatively, quantum dot materials containing elements such as cadmium, selenium, zinc, sulfur, phosphorous, indium, tellurium, lead, gallium, arsenic, aluminum, and the like may be used.

[adhesive layer]

As the adhesive layer, various curable adhesives, such as photocurable adhesives such as ultraviolet curable adhesives, reaction curable adhesives, thermosetting adhesives, and anaerobic adhesives, can be used. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, and PVB (polyvinyl butyral) resin, EVA (ethylene-vinyl acetate) resin, etc. In particular, it is preferable to use a material with low moisture permeability such as epoxy resin. In addition, a two-liquid mixed type resin can also be used. In addition, an adhesive sheet or the like can also be used.

In addition, a drying agent may be contained in the said resin. For example, a substance that adsorbs moisture by chemical adsorption, such as an oxide of an alkaline earth metal (calcium oxide, barium oxide, etc.), can be used. Alternatively, a substance that adsorbs moisture by physical adsorption, such as zeolite or silica gel, may be used. When a desiccant is included in the resin, it is possible to prevent impurities such as moisture from entering the element, thereby improving the reliability of the display panel, which is preferable.

In addition, by mixing a filler with a high refractive index or a light-scattering member in the above-mentioned resin, the light extraction efficiency can be improved. For example, titanium oxide, barium oxide, zeolite, zirconium and the like can be used.

[connection layer]

As a connection layer, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), etc. can be used.

[color layer]

As a material which can be used for a color layer, a metal material, a resin material, a resin material containing a pigment or a dye, etc. are mentioned.

[shading layer]

As a material that can be used for the light-shielding layer, carbon black, titanium black, metal, metal oxide, or a composite oxide containing a solid solution of a plurality of metal oxides can be mentioned. The light shielding layer may be a film containing a resin material or a thin film containing an inorganic material such as a metal. Moreover, the laminated film of the film containing the material of a color layer can also be used for the light-shielding layer. For example, a laminated structure of a film containing a material for a color layer for transmitting light of a certain color and a film containing a material for a color layer for transmitting light of another color can be employed. By making the material of the color layer and the light shielding layer the same, in addition to using the same device, the manufacturing process can be simplified, which is preferable.

At least a part of this embodiment can be implemented in combination with other embodiments described in this specification as appropriate.

Embodiment 5

In the present embodiment, an example of a transistor that can be used in place of each transistor shown in the above-described embodiment will be described with reference to the drawings.

The display device according to one embodiment of the present invention can be manufactured using various types of transistors, such as bottom gate type transistors and top gate type transistors. Therefore, the semiconductor layer material or transistor structure used can be easily changed to correspond to the conventional production line.

<5-1. Bottom gate type transistor>

28A1 is a cross-sectional view in the channel length direction of a channel protection transistor 810, which is one type of bottom gate transistor. 28A2 , 28B1 , 28B2 , 28C1 and 28C2 are cross-sectional views in the channel length direction of the bottom gate type transistor.

In FIG. 28A1, transistor 810 is formed on substrate 771. In addition, the transistor 810 includes the electrode 746 on the substrate 771 with the insulating layer 772 interposed therebetween. In addition, the semiconductor layer 742 is included on the electrode 746 with the insulating layer 726 interposed therebetween. Electrode 746 may be used as a gate electrode. The insulating layer 726 may be used as a gate insulating layer.

In addition, an insulating layer 741 is included on the channel formation region of the semiconductor layer 742 . In addition, an electrode 744a and an electrode 744b are included on the insulating layer 726 so as to be in contact with a part of the semiconductor layer 742 . The electrode 744a may be used as one of a source electrode and a drain electrode. The electrode 744b may be used as the other of the source electrode and the drain electrode. A part of the electrode 744a and a part of the electrode 744b are formed on the insulating layer 741.

The insulating layer 741 may be used as a channel protection layer. By providing the insulating layer 741 on the channel formation region, the semiconductor layer 742 can be prevented from being exposed when the electrodes 744a and 744b are formed. Thereby, the channel formation region of the semiconductor layer 742 can be prevented from being etched when the electrodes 744a and 744b are formed. According to one embodiment of the present invention, a transistor having good electrical characteristics can be realized.

In addition, the transistor 810 includes an insulating layer 728 on the electrodes 744 a , 744 b , and the insulating layer 741 , and includes an insulating layer 729 on the insulating layer 728 .

When an oxide semiconductor is used for the semiconductor layer 742, it is preferable to use a material capable of extracting oxygen from a part of the semiconductor layer 742 to generate oxygen vacancies for the electrode 724a and the electrode 724b at least in contact with the semiconductor layer 742. In the semiconductor layer 742, the carrier concentration of the region where oxygen vacancies are generated increases, and the region is n-typed to become an n-type region (n ⁺ layer). Therefore, this region can be used as a source region or a drain region. When an oxide semiconductor is used for the semiconductor layer 742, tungsten, titanium, etc. are mentioned as an example of the material which can extract oxygen from the semiconductor layer 742 to generate oxygen vacancies.

By forming the source region and the drain region in the semiconductor layer 742, the contact resistance between the electrode 724a and the electrode 724b and the semiconductor layer 742 can be reduced. Therefore, the electrical characteristics of the transistor such as field mobility and threshold voltage can be improved.

When a semiconductor such as silicon is used for the semiconductor layer 742, it is preferable to provide a layer serving as an n-type semiconductor or a p-type semiconductor between the semiconductor layer 742 and the electrode 724a and between the semiconductor layer 742 and the electrode 724b. Layers that function as n-type semiconductors or p-type semiconductors can be used as source regions or drain regions of transistors.

The insulating layer 729 is preferably formed using a material having a function of preventing impurities from diffusing into the transistor from the outside or reducing the diffusion of impurities. In addition, the insulating layer 729 may be omitted as necessary.

The transistor 811 shown in FIG. 28A2 differs from the transistor 810 in that an electrode 723 that can be used as a back gate electrode is included on the insulating layer 729 . The electrode 723 can be formed using the same material and method as the electrode 746 .

Generally, the back gate electrode is formed using a conductive layer, and is provided so that the channel formation region of the semiconductor layer is sandwiched between the gate electrode and the back gate electrode. Therefore, the back gate electrode can have the same function as the gate electrode. The potential of the back gate electrode may be equal to that of the gate electrode, or may be a ground potential (GND potential) or an arbitrary potential. In addition, by changing the potential of the back gate electrode independently of the gate electrode, the threshold voltage of the transistor can be changed.

29A1 , 29A2 , 29B1 , 29B2 , 29C1 and 29C2 respectively show a cross-sectional view in the channel width direction of the transistor 810 , a cross-sectional view in the channel width direction of the transistor 811 , and a cross-sectional view in the channel width direction of the transistor 820 , respectively. A cross-sectional view, a cross-sectional view in the channel width direction of the transistor 821 , a cross-sectional view in the channel width direction of the transistor 825 , and a cross-sectional view in the channel width direction of the transistor 826 .

In the structures shown in FIGS. 29B2 and 29C2 , the gate electrode and the back gate electrode are connected to each other, whereby the potential of the gate electrode and the back gate electrode are the same.

In addition, in the structures shown in FIGS. 29B2 and 29C2 , the semiconductor layer 742 is sandwiched between the gate electrode and the back gate electrode. In the channel width direction, the gate electrode and the back gate electrode are longer than the semiconductor layer 742, and the entire semiconductor layer 742 is covered by the gate electrode or the back gate electrode with the insulating layers 726, 741, 728, 729 interposed therebetween. By adopting this structure, the semiconductor layer 742 included in the transistor can be electrically surrounded by the electric field of the gate electrode and the back gate electrode.

A device structure such as the transistor 821 or the transistor 826 in which the semiconductor layer 742 forming the channel region is electrically surrounded by the electric field of the gate electrode and the back gate electrode can be called a Surrounded channel (S-channel: Surrounded channel) structure.

By adopting the S-channel structure, an electric field for inducing a channel can be effectively applied to the semiconductor layer 742 using one or both of the gate electrode and the back gate electrode. As a result, the current driving capability of the transistor is improved, so that a higher on-state current characteristic can be obtained. Furthermore, since the on-state current can be increased, the transistor can be miniaturized. In addition, by adopting the S-channel structure, the mechanical strength of the transistor can be improved.

In addition, both the electrode 746 and the electrode 723 may be used as gate electrodes. Therefore, the insulating layer 726, the insulating layer 729, the insulating layer 728, and the insulating layer 729 may all be used as gate insulating layers. In addition, the electrode 723 may be provided between the insulating layer 728 and the insulating layer 729 .

Note that when one of the electrode 746 and the electrode 723 is referred to as a "gate electrode", the other is referred to as a "back gate electrode". For example, in transistor 811, when electrode 723 is referred to as a "gate electrode", electrode 746 is referred to as a "back gate electrode". In addition, when the electrode 723 is used as a "gate electrode", the transistor 811 is one of the top gate type transistors. In addition, one of the electrode 746 and the electrode 723 is sometimes referred to as a "first gate electrode", and the other is sometimes referred to as a "second gate electrode".

By providing the electrode 746 and the electrode 723 with the semiconductor layer 742 interposed therebetween and setting the potentials of the electrode 746 and the electrode 723 to be the same, the region in which the carriers flow in the semiconductor layer 742 is further expanded in the film thickness direction, so that the movement of the carriers is prevented. volume increase. As a result, the on-state current of the transistor 811 increases, and the field-effect mobility also increases.

Therefore, the transistor 811 is a transistor having a large on-state current with respect to the occupied area. That is, the occupied area of the transistor 811 can be reduced with respect to the required on-state current. According to one embodiment of the present invention, the occupied area of the transistor can be reduced. Therefore, according to one embodiment of the present invention, a highly integrated semiconductor device can be realized.

In addition, since the gate electrode and the back gate electrode are formed using a conductive layer, they have a function of preventing an electric field generated outside the transistor from affecting the semiconductor layer forming the channel (especially, an electric field shielding function against static electricity and the like). In addition, when the back gate electrode is formed larger than the semiconductor layer to cover the semiconductor layer with the back gate electrode, the electric field shielding function can be improved.

In addition, by forming the back gate electrode using a light-shielding conductive film, light can be prevented from entering the semiconductor layer from the back gate electrode side. As a result, it is possible to prevent optical degradation of the semiconductor layer and to prevent degradation of electrical characteristics such as threshold voltage shift of the transistor.

According to one embodiment of the present invention, a transistor with good reliability can be realized. In addition, a semiconductor device with good reliability can be realized.

FIG. 28B1 shows a cross-sectional view of a channel protection type transistor 820 which is one of the bottom gate type transistors. The transistor 820 has substantially the same structure as the transistor 810 , except that the insulating layer 741 covers the end of the semiconductor layer 742 . The semiconductor layer 742 is electrically connected to the electrode 744a in the opening formed by selectively removing the portion of the insulating layer 729 overlapping the semiconductor layer 742 . In addition, the semiconductor layer 742 is electrically connected to the electrode 744b in another opening formed by selectively removing the portion of the insulating layer 729 overlapping the semiconductor layer 742 . A region of the insulating layer 729 overlapping the channel formation region may be used as a channel protective layer.

The transistor 821 shown in FIG. 28B2 differs from the transistor 820 in that an electrode 723 that can be used as a back gate electrode is included on the insulating layer 729 .

By providing the insulating layer 729, the semiconductor layer 742 can be prevented from being exposed when the electrodes 744a and 744b are formed. Therefore, the semiconductor layer 742 can be prevented from being thinned when the electrodes 744a and 744b are formed.

In addition, the distance between the electrode 744a and the electrode 746 of the transistor 820 and the transistor 821 and the distance between the electrode 744b and the electrode 746 are longer than those of the transistor 810 and the transistor 811 . Therefore, the parasitic capacitance generated between the electrode 744a and the electrode 746 can be reduced. Furthermore, the parasitic capacitance generated between the electrode 744b and the electrode 746 can be reduced. According to one embodiment of the present invention, a transistor having excellent electrical characteristics can be provided.

The transistor 825 shown in FIG. 28C1 is a channel etch type transistor which is one of the bottom gate type transistors. In the transistor 825, the electrode 744a and the electrode 744b are formed without using the insulating layer 729. Therefore, a part of the semiconductor layer 742 exposed when the electrodes 744a and 744b are formed may be etched. On the other hand, since the insulating layer 729 is not provided, the productivity of the transistor can be improved.

The transistor 825 shown in FIG. 28C2 differs from the transistor 820 in that it has an electrode 723 on an insulating layer 729 that can be used as a back gate electrode.

<5-2. Top-gate transistor>

FIG. 30A1 shows a cross-sectional view in the channel length direction of transistor 830, which is one of the top gate type transistors. The transistor 830 has a semiconductor layer 742 on the insulating layer 772, an electrode 744a in contact with a part of the semiconductor layer 742, and an electrode 744b in contact with a part of the semiconductor layer 742 on the semiconductor layer 742 and the insulating layer 772. The insulating layer 726 is provided on the electrode 744 a and the electrode 744 b , and the electrode 746 is provided on the insulating layer 726 . 30A2 , 30A3 , 30B1 and 30B2 are cross-sectional views in the channel length direction of the top gate type transistor.

Since in the transistor 830, the electrode 746 and the electrode 744a and the electrode 746 and the electrode 744b do not overlap, the parasitic capacitance generated between the electrode 746 and the electrode 744a and the parasitic capacitance generated between the electrode 746 and the electrode 744b can be reduced . In addition, after the electrode 746 is formed, the electrode 746 is used as a mask and the impurity 755 is introduced into the semiconductor layer 742, whereby impurity regions can be formed in the semiconductor layer 742 in a self-aligned manner (refer to FIG. 30A3). According to one embodiment of the present invention, a transistor having good electrical characteristics can be realized.

In addition, the introduction of the impurity 755 may be performed using an ion implantation apparatus, an ion doping apparatus, or a plasma processing apparatus.

As the impurity 755, for example, at least one element selected from Group 13 elements and Group 15 elements can be used. In addition, in the case of using an oxide semiconductor as the semiconductor layer 742 , as the impurity 755 , at least one element selected from the group consisting of rare gas, hydrogen, and nitrogen may be used.

The transistor 831 shown in FIG. 30A2 is different from the transistor 830 in that it has an electrode 723 and an insulating layer 727 . The transistor 831 has an electrode 723 formed on the insulating layer 772 and an insulating layer 727 formed on the electrode 723 . Electrode 723 may be used as a back gate electrode. Therefore, the insulating layer 727 can be used as a gate insulating layer. The insulating layer 727 can be formed using the same material and method as the insulating layer 726 .

Like the transistor 811, the transistor 831 is a transistor having a large on-state current with respect to the occupied area. That is, the occupied area of the transistor 831 can be reduced with respect to the required on-state current. According to one embodiment of the present invention, the occupied area of the transistor can be reduced. Therefore, according to one embodiment of the present invention, a highly integrated semiconductor device can be realized.

The transistor 840 shown in FIG. 30B1 is one of the top gate type transistors. The transistor 840 is different from the transistor 830 in that the semiconductor layer 742 is formed after the electrode 744a and the electrode 744b are formed. In addition, the transistor 841 shown in FIG. 30B2 is different from the transistor 840 in that it has an electrode 723 and an insulating layer 727 . In the transistor 840 and the transistor 841, a part of the semiconductor layer 742 is formed on the electrode 744a, and the other part of the semiconductor layer 742 is formed on the electrode 744b.

Like the transistor 811, the transistor 841 is a transistor having a large on-state current with respect to the occupied area. That is, the occupied area of the transistor 841 can be reduced with respect to the required on-state current. According to one embodiment of the present invention, the occupied area of the transistor can be reduced. Therefore, according to one embodiment of the present invention, a highly integrated semiconductor device can be realized.

31A1 , 31A2 , 31B1 , and 31B2 respectively show a cross-sectional view in the channel width direction of the transistor 830 shown in FIG. 30A1 , a cross-sectional view in the channel width direction of the transistor 831 shown in FIG. 30A2 , and FIG. 30B1 , respectively. A cross-sectional view in the channel width direction of the transistor 840 shown and a cross-sectional view in the channel width direction of the transistor 841 shown in FIG. 30B2 .

The transistor 831 and the transistor 841 have the above-mentioned S-channel structure. However, it is not limited to this, and the transistor 831 and the transistor 841 may not have the S-channel structure.

FIGS. 32A1 to 32C2 and FIGS. 33A1 to 33C2 illustrate top-gate transistors in different ways from the transistors shown in FIGS. 30A1 to 30B2 and 31A1 to 31B2 .

32A1 , 32A2 , 32B1 , 32B2 , 32C1 and 32C2 are a cross-sectional view of the transistor 842 along the channel length, a cross-sectional view of the transistor 843 along the channel length, and a cross-sectional view of the transistor 844 along the channel length, respectively. , a cross-sectional view along the channel length of the transistor 845 , a cross-sectional view along the channel length of the transistor 846 , and a cross-sectional view along the channel length of the transistor 847 .

32A3 is a cross-sectional view illustrating a process in the channel length direction of the transistor 842. FIG.

The transistor 842 shown in FIG. 32A1 is different from the transistor 830 or the transistor 840 in that the electrode 744a and the electrode 744b are formed after the insulating layer 729 is formed. The electrodes 744a and 744b are electrically connected to the semiconductor layer 742 at openings formed in the insulating layer 728 and the insulating layer 729.

In addition, a part of the insulating layer 726 that does not overlap with the electrode 746 is removed, and the electrode 746 and the remaining insulating layer 726 are used as masks to introduce the impurity 755 into the semiconductor layer 742, so that the semiconductor layer 742 can be self-aligned (self-aligned). -alignment) to form impurity regions (see FIG. 32A3 ). Transistor 842 includes regions where insulating layer 726 extends beyond the ends of electrodes 746 . When the impurity 755 is introduced into the semiconductor layer 742 , the impurity concentration of the region of the semiconductor layer 742 into which the impurity 755 is introduced through the insulating layer 726 is lower than that of the region where the impurity 755 is not introduced through the insulating layer 726 . Therefore, an LDD (Lightly Doped Drain) region is formed in a region of the semiconductor layer 742 that does not overlap with the electrode 746 .

The transistor 843 shown in FIG. 32A2 is different from the transistor 842 in that the electrode 723 is included. The transistor 843 includes the electrode 723 formed on the substrate 771 and overlapping the semiconductor layer 742 with the insulating layer 772 interposed therebetween. Electrode 723 may be used as a back gate electrode.

In addition, like the transistor 844 shown in FIG. 32B1 and the transistor 845 shown in FIG. 32B2 , the insulating layer 726 in the region not overlapping the electrode 746 may be removed. In addition, like the transistor 846 shown in FIG. 32C1 and the transistor 847 shown in FIG. 32C2 , the insulating layer 726 may be left.

In the transistors 842 to 847 , impurities 755 may be introduced into the semiconductor layer 742 using the electrode 746 as a mask after the electrode 746 is formed, thereby forming an impurity region in the semiconductor layer 742 in a self-aligned manner. According to one embodiment of the present invention, a transistor having good electrical characteristics can be realized. In addition, according to an embodiment of the present invention, a semiconductor device with a high degree of integration can be realized.

33A1 , 33A2 , 33B1 , 33B2 , 33C1 and 33C2 respectively show a cross-sectional view in the channel width direction of the transistor 842 shown in FIG. 32A1 and a channel width direction of the transistor 843 shown in FIG. 32A2 , respectively. 32B1, a cross-sectional view in the channel width direction of the transistor 844 shown in FIG. 32B1, a cross-sectional view in the channel width direction of the transistor 845 shown in FIG. 32B2, and a cross section in the channel width direction of the transistor 846 shown in FIG. 32C1. FIG. 32C2 is a cross-sectional view of the transistor 847 in the channel width direction.

The transistor 843, the transistor 845, and the transistor 847 have the above-mentioned S-channel structure. However, it is not limited to this, and the transistor 843, the transistor 845, and the transistor 847 may not have the S-channel structure.

In addition, FIGS. 34A1 and 34A2 show modified examples of the transistor 845 shown in FIGS. 32B2 and 33B2 . 34A1 is a cross-sectional view in the channel length direction of the transistor 845A, and FIG. 34A2 is a cross-sectional view in the channel width direction of the transistor 845A.

The transistor 845A shown in FIGS. 34A1 and 34A2 differs from the transistor 845 in the positions of the insulating layer 729 and the insulating layer 728 . Other than that, the transistor 845A has the same structure as the transistor 845 .

At least a part of this embodiment can be implemented in combination with other embodiments described in this specification as appropriate.

Embodiment 6

In this embodiment, a display module that can be manufactured using an embodiment of the present invention will be described.

<6. Display module>

The display module 6000 shown in FIG. 35A includes a display panel 6006 connected to the FPC 6005 , a frame 6009 , a printed circuit board 6010 and a battery 6011 between the upper cover 6001 and the lower cover 6002 .

For example, a display device manufactured using an embodiment of the present invention can be used for the display panel 6006 . Thereby, the display module can be manufactured with high yield.

The upper cover 6001 and the lower cover 6002 can be appropriately changed in shape or size according to the size of the display panel 6006 .

The frame 6009 has, in addition to the function of protecting the display panel 6006 , the function of an electromagnetic shield for shielding electromagnetic waves generated by the operation of the printed circuit board 6010 . In addition, the frame 6009 may also function as a heat dissipation plate.

The printed circuit board 6010 includes a power supply circuit and a signal processing circuit for outputting video signals and clock signals. As a power supply for supplying power to the power supply circuit, an external commercial power supply or a power supply of a separately provided battery 6011 may be used. When a commercial power source is used, the battery 6011 can be omitted.

In addition, the display module 6000 may also be provided with components such as a polarizing plate, a retardation plate, and a mirror film.

As shown in Embodiment 1, the display panel 6006 includes a touch sensor as an input device. As the method of the touch sensor, a resistive film type or an electrostatic capacitance type may be used.

In addition, the structure shown in FIG. 35B can also be adopted without disposing the touch sensor in the display panel 6006 . 35B is a schematic cross-sectional view of a display module 6000 including an optical touch sensor. In addition, although not shown, it is also possible to use a combination of an electrostatic capacitive touch sensor and an optical touch sensor.

The display module 6000 shown in FIG. 35B includes a light-emitting portion 6015 and a light-receiving portion 6016 disposed on the printed circuit board 6010 . In addition, a pair of light guide portions (light guide portion 6017a, light guide portion 6017b) are included in an area surrounded by the upper cover 6001 and the lower cover 6002.

The upper cover 6001 and the lower cover 6002 can be made of plastic, for example. In addition, the thickness of the upper cover 6001 and the lower cover 6002 can be reduced (eg, 0.5 mm or more and 5 mm or less), respectively. Therefore, the weight of the display module 6000 can be extremely light. In addition, since the upper cover 6001 and the lower cover 6002 can be formed using less material, the manufacturing cost can be reduced.

The display panel 6006 is provided so as to overlap with the printed circuit board 6010 and the battery 6011 via the frame 6009 . The display panel 6006 and the frame 6009 are fixed to the light guide portion 6017a and the light guide portion 6017b.

The light 6018 emitted from the light emitting portion 6015 passes through the upper portion of the display panel 6006 through the light guide portion 6017a, and reaches the light receiving portion 6016 through the light guide portion 6017b. For example, a touch operation can be detected when the light 6018 is blocked by a detection object such as a finger or a stylus.

The plurality of light emitting parts 6015 are provided along, for example, two adjacent sides of the display panel 6006 . The plurality of light receiving units 6016 are arranged at positions facing the light emitting unit 6015 with the display panel 6006 interposed therebetween. Thereby, information on the position of the touch operation can be acquired.

As the light-emitting portion 6015, a light source such as an LED element can be used, for example. In particular, as the light-emitting portion 6015, it is preferable to use a light source that emits infrared rays which are not visible to the user and are harmless to the user.

As the light-receiving portion 6016, a photoelectric element that receives the light emitted by the light-emitting portion 6015 and converts it into an electrical signal can be used. Preferably, a photodiode capable of receiving infrared rays is used.

As the light guide portion 6017a and the light guide portion 6017b, a member that transmits at least the light 6018 can be used. By using the light guide portion 6017a and the light guide portion 6017b, the light-emitting portion 6015 and the light-receiving portion 6016 can be arranged on the lower side of the display panel 6006, thereby preventing external light from reaching the light-receiving portion 6016 and causing malfunction of the touch sensor. In particular, it is preferable to use a resin that absorbs visible light and transmits infrared rays. Thereby, the erroneous operation of the touch sensor is more effectively suppressed.

At least a part of this embodiment can be implemented in combination with other embodiments described in this specification as appropriate.

Embodiment 7

In this embodiment mode, an electronic device to which the display device according to an embodiment of the present invention can be applied will be described with reference to FIGS. 36A to 40B .

<7-1. Electronic device 1>

First, an example of an electronic device will be described with reference to FIGS. 36A to 37C . The display device of one embodiment of the present invention can achieve high visibility regardless of the intensity of external light. Thereby, it can be suitably applied to portable electronic devices, wearable electronic devices, e-book readers, televisions, digital signboards, and the like.

An example of the portable information terminal 1800 is shown in FIGS. 36A and 36B. The portable information terminal 1800 includes a casing 1801, a casing 1802, a display part 1803, a display part 1804, a hinge part 1805, and the like.

The housing 1801 and the housing 1802 are connected together by a hinge portion 1805 . The portable information terminal 1800 can be converted from the folded state shown in FIG. 36A to the unfolded state of the case 1801 and the case 1802 shown in FIG. 36B .

For example, document information can be displayed on the display unit 1803 and the display unit 1804, whereby the portable information terminal can be used as an e-book reader. In addition, still images or moving images may be displayed on the display unit 1803 and the display unit 1804 .

In this way, the portable information terminal 1800 can be in a folded state when being carried, so the versatility is excellent.

In addition, the housing 1801 and the housing 1802 may also include a power button, an operation button, an external connection port, a speaker, a microphone, and the like.

FIG. 36C shows an example of a portable information terminal. The portable information terminal 1810 shown in FIG. 36C includes a casing 1811, a display portion 1812, operation buttons 1813, an external connection port 1814, a speaker 1815, a microphone 1816, a camera 1817, and the like.

The display unit 1812 includes a display device according to an embodiment of the present invention.

In the portable information terminal 1810, the display unit 1812 has a touch sensor. By touching the display unit 1812 with a finger, a stylus, or the like, various operations such as making a call or inputting characters can be performed.

In addition, by operating the operation button 1813 , the power supply can be turned on or off, or the type of video displayed on the display unit 1812 can be switched. For example, you can switch the compose screen of an email to the main menu screen.

In addition, by arranging detection devices such as a gyro sensor or an acceleration sensor in the portable information terminal 1810, the orientation (portrait or landscape) of the portable information terminal 1810 can be determined, and the screen of the display unit 1812 can be detected. The display orientation is automatically switched. In addition, switching of the screen display may be performed by touching the display unit 1812 , operating the operation buttons 1813 , or inputting a sound using the microphone 1816 .

The portable information terminal 1810 has, for example, one or more functions selected from a telephone, a notebook, and an information reading device. Specifically, the portable information terminal 1810 can be used as a smart phone. The portable information terminal 1810 can execute various application programs such as mobile phone, e-mail, reading and editing of articles, music playback, animation playback, network communication, and computer games.

FIG. 36D shows an example of a camera. The camera 1820 includes a housing 1821, a display portion 1822, operation buttons 1823, a shutter button 1824, and the like. In addition, a detachable lens 1826 is attached to the camera 1820 .

The display unit 1822 includes a display device according to an embodiment of the present invention.

Here, although the camera 1820 has a structure in which the lens 1826 can be detached from the housing 1821 and exchanged, the lens 1826 and the housing may be integrally formed.

By pressing the shutter button 1824, the camera 1820 can capture still images or moving images. Alternatively, the display unit 1822 may function as a touch panel, and an image may be captured by touching the display unit 1822 .

In addition, the camera 1820 may further include a flash device, a viewfinder, and the like that are separately attached. In addition, these components may also be assembled in the housing 1821.

FIG. 37A shows a television 1830. FIG. The television 1830 includes a display portion 1831, a casing 1832, a speaker 1833, and the like. In addition, LED lights, operation keys (including power switches or operation switches), connection terminals, various sensors, and microphones may also be included.

The television 1830 can be operated using the remote control 1834 .

The broadcast radio waves that can be received by the television set 1830 include terrestrial waves, radio waves transmitted from satellites, and the like. In addition, as broadcast waves, there are analog broadcasts, digital broadcasts, and the like, as well as video and audio broadcasts, audio-only broadcasts, and the like. For example, broadcast waves transmitted in designated frequency bands in the UHF band (about 300MHz to 3GHz) or the VHF band (30MHz to 300MHz) can be received. For example, by using multiple data received in multiple frequency bands, the transmission rate can be increased so that more information can be obtained. This makes it possible to display on the display unit 1831 a video with a resolution exceeding full high definition. For example, images with 4K, 8K, 16K or higher resolution can be displayed.

In addition, a configuration may be adopted in which the video displayed on the display unit 1831 is generated using broadcast data using the Internet, LAN (Local Area Network), Wi-Fi (registered trademark. Wireless Fidelity) and other computer network data transmission technology. At this time, the television 1830 may not include a tuner.

FIG. 37B shows a digital signboard 1840 provided on a column 1842 in a cylindrical shape. The digital signboard 1840 includes a display portion 1841 .

The larger the display portion 1841 is, the larger the amount of information that the display device can provide at one time. The larger the display portion 1841 is, the easier it is to attract attention, for example, the effect of advertising can be improved.

By using the touch panel for the display unit 1841, not only a still image or a moving image can be displayed on the display unit 1841, but also the user can operate intuitively, which is preferable. In addition, when it is used for providing information such as route information and traffic information, the usability can be improved by intuitive operation.

FIG. 37C shows a laptop personal computer 1850. The personal computer 1850 includes a display unit 1851, a casing 1852, a touch panel 1853, a connection port 1854, and the like.

The touchpad 1853 is used as an input unit of a pointing device or a tablet, and can be operated with a finger, a stylus, or the like.

The touch panel 1853 is assembled with display elements. As shown in FIG. 37C , the touchpad 1853 can be used as a keyboard by displaying the input keys 1855 on the surface of the touchpad 1853 . At this time, in order to reproduce the tactile sensation by vibration when the input key 1855 is touched, a vibration module may be incorporated in the touch panel 1853 .

<7-2. Electronic device 2>

Next, an example of an electronic device will be described with reference to FIGS. 38 , 39A, and 39B. Figure 38 shows a foldable electronic device.

The electronic device 920 shown in FIG. 38 is provided with a flexible display portion 922 across a housing 921 a and a housing 921 b connected to each other by a hinge 923 .

In FIG. 38C, when the case 921a and the case 921b are unfolded, the display portion 922 is kept in a state of being largely bent. For example, the display portion 922 may be held in a state where the radius of curvature is 1 mm or more and 50 mm or less, preferably 5 mm or more and 30 mm or less. A part of the display unit 922 has pixels continuously arranged across the casing 921a and the casing 921b, and can display on a curved surface.

In order to avoid the angle created by the housings 921a and 921b when the housings are opened exceeding a predetermined angle, the hinge 923 preferably has a locking mechanism. For example, the locking angle (no further opening when the angle is reached) is preferably more than 90° and less than 180°, and typically, it can be 90°, 120°, 135° or 160°, 175°, etc. Thereby, convenience, safety, and reliability can be improved.

Since the hinge 923 has the above-described locking mechanism, it is possible to prevent the display portion 922 from being damaged due to excessive pressure being applied to the display portion 922 . Therefore, an electronic device with high reliability can be realized.

39A and 39B illustrate an electronic device 950 used as a portable game machine or a tablet information terminal. In addition, in order to improve portability, the electronic device 950 can be folded in half, FIG. 39A is a perspective view of the folded state, and FIG. 39B is a perspective view of the state where the electronic device 950 is unfolded at an angle of about 160° to 175°.

The electronic device 950 includes a housing 952a, a housing 952b, a display portion 954, a hinge portion 953, and the like. In addition, the shape of the display area of the display unit 954 included in the electronic device 950 is not a rectangle, but a shape where only the display area of the area where the hinge unit 953 is located is reduced.

The surface of the display portion 954 has convex portions. In addition, in the display part 954, the area|region which overlaps with the casing 952a and the casing 952b has a flat surface, and the area|region overlapping with the hinge part 953 has a curved surface.

Figure 40A shows a perspective view of electronic device 950 in a different manner than Figure 39B. In addition, FIG. 40B is a side view of the electronic device 950 shown in FIG. 40A .

40A is a perspective view of a structure in which a convex portion is provided on a surface of a display portion 954 included in the electronic device 950 shown in FIG. 39B .

As shown in FIG. 40A , the display portion 954 includes a plurality of convex portions 954a. Note that although FIG. 40A shows a configuration in which a plurality of convex portions 954a are arranged, the present invention is not limited to this, and one convex portion 954a may be provided.

The convex portion 954a has a function of allowing the operator to perceive the operation position. For example, since the display unit 954 includes a touch sensor, by operating the display unit 954 , operations such as input can be performed on the electronic device 950 . However, when the convex portion 954a is not provided, if the display portion 954 cannot be seen, there is a problem that the operator cannot perceive the operation position. On the other hand, by providing the convex portion 954a, even if the display portion 954 cannot be seen, the operation position can be sensed simply by touching the convex portion 954a provided on the display portion 954, and operations such as input can be performed easily.

In other words, the electronic device 950 shown in FIG. 40A includes a display portion 954 and a convex portion 954a provided on the display portion 954, and an input to the display portion 954 can be performed by touching the convex portion 954a.

Further, by providing the convex portion 954a, it is not necessary to provide physical buttons for games or the like, so that various materials for the physical buttons can be reduced, which is preferable.

The convex portion 954a is preferably, for example, the anti-glare pattern 13c that also serves as the anti-reflection layer shown in FIGS. 2A to 2F . For example, the convex portion 954a can be formed by forming the anti-glare pattern 13c to have a particle size of 1 μm or more and 100 μm or less, and concentrating a plurality of the anti-glare patterns 13c in the region of the convex portion 954a. Note that the structure of the convex portion 954a is not limited to this, and a structure is formed using a resin material such as acrylic resin or polyimide, and the convex portion 954a having a size that can be perceived by the user is formed on the display portion 954 . Further, when the protrusions 954a can be formed without making the anti-glare patterns 13c dense, one anti-glare pattern 13c may also be used. In this case, silica particles or the like that can be perceived by the user may be provided on the display portion 954 .

As shown in FIG. 40B , the display portion 954 has a convex portion 954a and a curved surface. FIG. 40B is a side view of the electronic device 950 , in which a region 961 surrounded by dashed lines and a region 962 surrounded by dashed lines are enlarged and shown.

A region 961 is an enlarged side view of the convex portion 954 a , and a region 962 is an enlarged view of the display portion 954 in the vicinity of the hinge portion 953 .

As shown in the area 961, the convex portion 954a is preferable because the operability is improved when the convex portion 954a protrudes from the housing 952b. In addition, as shown in the area 962 , the display portion 954 preferably has a curved surface near the hinge portion 953 . Since the display part 954 has a curved surface, the display part 954 of the area|region overlapping with the casing 952a and the display part 954 of the area|region overlapping with the casing 952b can be seen at a glance. In addition, since the display portion 954 has a curved surface, the reliability of the display portion 954 can be improved without causing the display portion 954 to be bent and broken.

The casing 952a, the casing 952b, and the hinge portion 953 preferably have a structure capable of accommodating the curved surface portion of the display portion 954. In other words, the housing 952 a , the housing 952 b , and the hinge portion 953 include a region for accommodating the display portion 954 .

At least a part of this embodiment can be implemented in combination with other embodiments described in this specification as appropriate.

11‧‧‧Substrate

12‧‧‧Substrate

13‧‧‧Anti-reflection layer

Floor 20‧‧‧

21‧‧‧Component layer

21a‧‧‧FET layer

21b‧‧‧LC layer

21b_LC‧‧‧LC layer

21c‧‧‧OLED layer

22‧‧‧Component layer

25‧‧‧Input device

26‧‧‧Adhesive layer

30‧‧‧Drive circuit

32‧‧‧FPC

Claims (8)

A display device comprising: a first substrate; a second substrate; a first display element; a second display element; and an input device, wherein the first substrate comprises a part of the first display element and the second display element, the The second substrate includes the input device, the first display element and the second display element are disposed between the first surface of the first substrate and the first surface of the second substrate, the first display element has a visible light reflective The second display element has the function of emitting visible light, and an anti-reflection layer is provided on the second surface opposite to the first surface of the second substrate. The display device according to claim 1, wherein the first display element and the second display element are disposed in the same pixel unit. The display device according to claim 1 of the claimed scope further comprises: a driving circuit, wherein the driving circuit has the function of driving the first display element, the second display element and the input device. The display device according to claim 1, wherein the first display element has a liquid crystal material, the second display element has an EL material, and the liquid crystal material has a dichroic dye. According to the display device of item 1 of the scope of the application, Wherein the anti-reflection layer has a convex portion. The display device according to claim 1, wherein one or more selected from a light diffusing plate, a polarizing plate, and a color film are included between the first display element and the input device. The display device according to claim 1, wherein the first display element and the second display element are respectively electrically connected to a transistor whose semiconductor layer forming a channel includes a metal oxide. An electronic device, comprising: the display device of any one of claims 1 to 7; a casing; and a hinge portion, wherein the casing and the hinge portion include an area for accommodating the display device.

Images