JP2018072745A - Display device and driving method of display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving method of a display device capable of avoiding or reducing image persistence.SOLUTION: A driving method is provided for a display device including first and second display elements. The first display element has a function of emitting visible light, and the second display element has a function of reflecting the visible light. The display device has a function of switching to display in the second display element when the same display in the first display element is continued for a certain period or repeated certain times or more. A driving method is also provided for a display device including the first and second display elements and a control section. The control section has a function of storing first display information of the first display element, and a function of generating second display information obtained by correcting the first display information according to the first display information stored in the control section. A driving method is also provided for a display device including the first and second display elements, the control section and a photometric section. The photometric section has a function of detecting external light illuminance, and the control section has a function of switching the display element to be used according to the external light illuminance detected by the photometric part.SELECTED DRAWING: Figure 1

Description

  One embodiment of the present invention relates to a display device. One embodiment of the present invention relates to a method for driving a display device.

  Note that one embodiment of the present invention is not limited to the above technical field. Technical fields of one embodiment of the present invention disclosed in this specification and the like include semiconductor devices, display devices, light-emitting devices, power storage devices, memory devices, electronic devices, lighting devices, input devices, input / output devices, and driving methods thereof , Or a method for producing them, can be mentioned as an example.

  Note that in this specification and the like, a semiconductor device refers to any device that can function by utilizing semiconductor characteristics. A transistor, a semiconductor circuit, an arithmetic device, a memory device, or the like is one embodiment of a semiconductor device. An imaging device, an electro-optical device, a power generation device (including a thin film solar cell, an organic thin film solar cell, and the like) and an electronic device may include a semiconductor device.

  In recent years, display devices are expected to be applied to various uses. As a display device, for example, a light emitting device having a light emitting element, a liquid crystal display device having a liquid crystal element, and the like have been developed.

  For example, Patent Document 1 discloses a flexible light emitting device to which an organic EL (Electroluminescence) element is applied.

  Patent Document 2 has a region that reflects visible light and a region that transmits visible light, and can be used as a reflective liquid crystal display device in an environment where sufficient external light is obtained. A transflective liquid crystal display device that can be used as a transmissive liquid crystal display device in an environment where the above cannot be obtained is disclosed.

JP 2014-197522 A JP 2011-191750 A

  In a display device using an organic EL element, a so-called “burn-in” problem may occur by displaying the same character or image for a long time. Burn-in is a problem in which the same display continues for a long time at a certain display location, thereby degrading the organic EL element or the like at the display location, and part of the display function within the display surface is impaired.

  An object of one embodiment of the present invention is to provide a display device and a driving method of the display device in which burn-in is avoided or reduced. Another object is to provide a display device with excellent display quality and a method for driving the display device. Another object of one embodiment of the present invention is to provide a display device that is easy on the eyes and a method for driving the display device. Another object of one embodiment of the present invention is to provide a highly reliable display device and a driving method of the display device. Another object of one embodiment of the present invention is to provide a display device with reduced power consumption and a method for driving the display device. Another object of one embodiment of the present invention is to provide a novel display device and a driving method of the display device.

  Note that the description of these problems does not disturb the existence of other problems. Note that one embodiment of the present invention does not necessarily have to solve all of these problems. Issues other than these will be apparent from the description of the specification, drawings, claims, etc., and other issues can be extracted from the descriptions of the specification, drawings, claims, etc. It is.

  One embodiment of the present invention is a method for driving a display device including a first display element and a second display element. The first display element has a function of emitting visible light. The display element has a function of reflecting visible light, and in the first period, the first step of displaying the first display information on the first display element, and the first display element in the first display element A second step of stopping display of the display information; and a third step of displaying the second display information on the second display element in the second period. After the first step, The first display information and the second display information are compared, and if the first display information and the second display information are the same, the second step and the third step are performed.

  Another embodiment of the present invention is a method for driving a display device including a first display element and a second display element, the first display element having a function of emitting visible light, A first step of displaying the first display information on the first display element, a second step of stopping the display of the first display information on the first display element, and a second step And a third step of displaying the second display information on the second display element in the period, and after performing the first step n times (n is an integer of 1 or more), the first display When the information is compared with the second display information and the first display information and the second display information are the same, the second step and the third step may be performed.

  Another embodiment of the present invention is a driving method of a display device described above, in which the display device includes a driving unit, and the driving unit supplies display information to be supplied to the first display element and the second display element. Display information to be displayed may be supplied at different timings.

  Another embodiment of the present invention is a driving method of a display device described above, in which the display device includes a driving unit, and the driving unit supplies display information to be supplied to the first display element and the second display element. Display information to be displayed may be supplied at the same time.

  One embodiment of the present invention is a display device including a first display element, a second display element, and a control unit, and the first display element has a function of emitting visible light, The second display element has a function of reflecting visible light. When the first display information and the second display information are the same, the control unit stops the display of the first display element, and the second display element The display element may have a function of displaying the second display information.

  One embodiment of the present invention is a display device including a first display element, a second display element, and a control unit, and the first display element has a function of emitting visible light, The second display element has a function of reflecting visible light, and the control unit, when the number of times of display of the first display information on the first display element is n times or more, includes the first display information and the second display information. The display information is compared, and when the first display information and the second display information are the same, the display of the first display element is stopped and the second display information is displayed on the second display element. You may have.

  One embodiment of the present invention is the above-described display device, in which the display device includes a driving portion, and the driving portion displays information supplied to the first display element and display information supplied to the second display element. May be provided at different timings.

  One embodiment of the present invention is the above-described display device, in which the display device includes a driving portion, and the driving portion displays information supplied to the first display element and display information supplied to the second display element. May be provided at the same time.

  According to one embodiment of the present invention, a display device and a driving method of the display device that can avoid or reduce image sticking can be provided. Alternatively, a display device with excellent display quality and a method for driving the display device can be provided. Alternatively, according to one embodiment of the present invention, a display device that is easy on the eyes and a method for driving the display device can be provided. Alternatively, according to one embodiment of the present invention, a highly reliable display device and a driving method of the display device can be provided. Alternatively, according to one embodiment of the present invention, a display device with reduced power consumption and a method for driving the display device can be provided. Alternatively, according to one embodiment of the present invention, a novel display device and a driving method of the display device can be provided.

  Note that the description of these effects does not disturb the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. It should be noted that the effects other than these are naturally obvious from the description of the specification, drawings, claims, etc., and it is possible to extract the other effects from the descriptions of the specification, drawings, claims, etc. It is.

1 is a block diagram of a display device according to one embodiment of the present invention. 4A and 4B each illustrate a pixel unit according to one embodiment of the present invention. 6 is a flowchart illustrating operation of a display device according to one embodiment of the present invention. 6 is a flowchart illustrating operation of a display device according to one embodiment of the present invention. 6 illustrates an example of temporal change in display luminance of a display portion according to one embodiment of the present invention. 7 shows a display example of a display portion according to one embodiment of the present invention. 4 illustrates a structure example of a display device according to one embodiment of the present invention. FIG. 10 is a circuit diagram of a pixel according to one embodiment of the present invention. FIG. 10 is a circuit diagram of a pixel according to one embodiment of the present invention. 1 is a schematic perspective view of a display panel according to one embodiment of the present invention. 4 illustrates a structure example of a display panel according to one embodiment of the present invention. 4 illustrates a structure example of a display panel according to one embodiment of the present invention. FIGS. 5A and 5B each illustrate an example of an electronic device and a lighting device according to one embodiment of the present invention. FIGS. FIG. 10 illustrates an example of an electronic device according to one embodiment of the present invention. FIG. 10 illustrates an example of an electronic device according to one embodiment of the present invention.

  Embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below.

  Note that in structures of the invention described below, the same portions or portions having similar functions are denoted by the same reference numerals in different drawings, and description thereof is not repeated. In addition, in the case where the same function is indicated, the hatch pattern is the same, and there is a case where no reference numeral is given.

  Note that in each drawing described in this specification, the size, the layer thickness, or the region of each component is exaggerated for simplicity in some cases. Therefore, it is not necessarily limited to the scale.

  In the present specification and the like, ordinal numbers such as “first” and “second” are used for avoiding confusion between components, and are not limited numerically.

  A transistor is a kind of semiconductor element, and can realize amplification of current and voltage, switching operation for controlling conduction or non-conduction, and the like. The transistor in this specification includes an IGFET (Insulated Gate Field Effect Transistor) and a thin film transistor (TFT: Thin Film Transistor).

(Embodiment 1)
In this embodiment, a display device of one embodiment of the present invention and a method for driving the display device will be described.

  The display device of one embodiment of the present invention is a display device in which a first display element that reflects visible light and a second display element that emits visible light are mixed.

  A display device according to one embodiment of the present invention includes a first pixel that expresses gradation by controlling the amount of reflected light, a light source, and a first unit that expresses gradation by controlling the amount of light of the light source. It has 2 pixels. A plurality of first pixels and second pixels are arranged in a matrix, respectively, and constitute a display unit. In addition, the display device preferably includes a driver that drives the first pixel and the second pixel. The driving unit is preferably configured to be driven by supplying different signals to the first pixel and the second pixel.

  In addition, it is preferable that the first pixels and the second pixels are arranged in the display area with the same number and the same pitch. At this time, the adjacent first pixel and second pixel can be collectively referred to as a pixel unit.

  Furthermore, the first pixel and the second pixel are preferably arranged in a mixed manner in the display area of the display device. Thereby, as will be described later, an image displayed with only the plurality of first pixels, an image displayed with only the plurality of second pixels, and the plurality of first pixels and the plurality of second pixels. Each of the images displayed on both can be displayed in the same display area.

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

  As the first display element, a reflective liquid crystal element can be typically used. Alternatively, as the first display element, a shutter type MEMS (Micro Electro Mechanical System) element, an optical interference type MEMS element, an element to which a microcapsule method, an electrophoresis method, an electrowetting method, or the like is applied are used. be able to.

  In addition, the second display element included in the second pixel includes a light source, and an element that performs display using light from the light source can be used. The light emitted from such a pixel is not affected by external light in brightness or chromaticity, and therefore has high color reproducibility (wide color gamut) and high contrast, that is, vivid display. be able to.

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

  The first pixel exhibits, for example, three colors of light of red (R), green (G), and blue (B), or three colors of light of cyan (C), magenta (M), and yellow (Y). A structure having sub-pixels can be employed. Similarly, the second pixel also has, for example, three colors of light of red (R), green (G), and blue (B), or three colors of cyan (C), magenta (M), and yellow (Y). It can be set as the structure which has the subpixel which each exhibits light. Note that the subpixels included in each of the first pixel and the second pixel may have four or more colors. As the number of subpixels increases, power consumption can be reduced and color reproducibility can be improved.

  The display device of one embodiment of the present invention includes a first mode in which an image is displayed with a first pixel, a second mode in which an image is displayed with a second pixel, and a first pixel and a second pixel. The third mode for displaying an image can be switched.

  The first mode is a mode in which an image is displayed using reflected light from the first display element. The first mode is a driving mode with extremely low power consumption because no light source is required. For example, it is effective when the illuminance of outside light is sufficiently high and the outside light is white light or light in the vicinity thereof. The first mode is a display mode suitable for displaying character information such as a book or a document, for example. In addition, since the reflected light is used, it is possible to perform display that is kind to the eyes, and the effect that the eyes are less tired is achieved.

  The second mode is a mode for displaying an image using light emission by the second display element. Therefore, an extremely vivid display (high contrast and high color reproducibility) can be performed regardless of the illuminance and chromaticity of external light. For example, it is effective when the illuminance of outside light is extremely small, such as at night or in a dark room. Further, when the outside light is dark, the user may feel dazzled when performing bright display. In order to prevent this, it is preferable to perform display with reduced luminance in the second mode. Thereby, in addition to suppressing glare, power consumption can also be reduced. The second mode is a mode suitable for displaying a vivid image or a smooth moving image.

  The third mode is a mode in which display is performed using both reflected light from the first display element and light emission from the second display element. Specifically, driving is performed so as to express one color by mixing light emitted by the first pixel and light emitted by the second pixel adjacent to the first pixel. While displaying more vividly than in the first mode, it is possible to suppress power consumption as compared with the second mode. For example, it is effective when the illuminance of outside light is relatively low, such as under room lighting or in the morning or evening hours, or when the chromaticity of outside light is not white. Further, by using light in which reflected light and light emission are mixed, it is possible to display an image that makes it feel as if the user is looking at a painting.

  As described above, the third mode is a mode that uses both the reflected light from the first display element and the light emission from the second display element. Therefore, the third display mode can be referred to as hybrid display.

  Hybrid display is a method of displaying characters or images on one panel by using reflected light and self-light emission in combination with each other to complement color tone or light intensity. Alternatively, the hybrid display is a method for displaying characters and / or images using light from a plurality of display elements in the same pixel or the same sub-pixel. However, when a hybrid display that performs hybrid display is viewed locally, the display is performed using pixels or sub-pixels displayed using any one of the plurality of display elements and two or more of the plurality of display elements. A pixel or a sub-pixel.

  Note that in this specification and the like, a display that satisfies any one or more expressions of the above configuration is referred to as a hybrid display.

  Moreover, the hybrid display has a plurality of display elements in the same pixel or the same sub-pixel. Examples of the plurality of display elements include a reflective element that reflects light and a self-luminous element that emits light. Note that the reflective element and the self-luminous element can be controlled independently. The hybrid display has a function of displaying characters and / or images using either one or both of reflected light and self-light emission in the display unit.

  Here, the configuration of the display device may include a display unit including the first pixel and the second pixel, a driving unit, a control unit, and a photometry unit. The control unit outputs the first signal output to the first pixel and the second pixel output to the second pixel based on image information input from the outside or external light information (illuminance, etc.) input from the photometry unit. 2 signal is generated and output. Here, the aforementioned image information is information including gradation values corresponding to each pixel unit, and examples thereof include video signals such as video signals. The first signal and the second signal generated and output by the control unit are supplied to the first pixel and the second pixel, respectively, via the driving unit. As described above, the driving unit is preferably configured to be able to be driven by supplying different signals to the first pixel and the second pixel.

  The control unit preferably has a function of processing the image information into a state suitable for display and storing the image information. The control unit preferably has a function of selecting the above-described display mode based on image information or / and external light information.

  Hereinafter, more specific examples of one embodiment of the present invention will be described with reference to the drawings.

<Configuration example of display device>
FIG. 1 is a block diagram of a display device 10 of one embodiment of the present invention. The display device 10 includes a control unit 11, a drive unit 13, and a display unit 14. The display device 10 may include a photometric unit 12 that detects the illuminance of external light.

  The control unit 11 includes a calculation unit 31 and a storage unit 32.

  A video signal S0 including image information is input to the calculation unit 31 from the outside. The image information included in the video signal S0 can be stored in the storage unit 32. The image information included in the video signal S0 is corrected (toning, dimming, etc.) to a state optimal for display by the calculation unit 31. It is preferable that the storage unit 32 and the calculation unit 31 have a configuration in which the above-described “storage” and “correction” of image information can be exchanged between each other.

  The calculation unit 31 is connected to the photometry unit 12 and corrects the image information to a state optimal for display (toning and toning) based on external light information (illuminance, etc.) L0 detected by the photometry unit 12. (Such as light).

  The drive unit 13 includes a first driver 15a and a second driver 15b. The first driver 15a and the second driver 15b have a function as, for example, a signal line driver circuit or a scanning line driver circuit. The first driver 15a is supplied with the first signal Sa from the control unit 11, and the second driver 15b is supplied with the second signal Sb from the control unit 11. Here, the first signal Sa and the second signal Sb are signals generated based on the image information corrected to the optimum state by the arithmetic unit 31 described above, and each pixel in the display unit 14 to be described later. It is a signal including the gradation value supplied to the unit. The first signal Sa and the second signal Sb may be the same signal or different signals.

  Although not shown in FIG. 1, the control unit 11 generates a timing signal such as a clock signal and a start pulse signal in addition to the first signal Sa and the second signal Sb and outputs the timing signal to the drive unit 13. It also has a function to

  The first driver 15 a can supply the first information Da to the display unit 14 based on the first signal Sa supplied from the control unit 11. Similarly, the second driver 15 b can supply the second information Db to the display unit 14 based on the second signal Sb supplied from the control unit 11. Specifically, the first information Da and the second information Db are information including a signal including a gradation value, a scanning signal, a power supply potential, and the like. The first information Da and the second information Db are supplied from the first driver 15a and the second driver 15b to the display unit 14 frame by frame at regular intervals. Here, the time per frame, the frame interval, and the like can be arbitrarily set by the control unit 11. Note that the first driver 15a and the second driver 15b can supply the first information Da and the second information Db to the display unit 14 at the same time, or can supply them individually.

  Although not shown in FIG. 1, the first driver 15a and the second driver 15b may have a frame memory. The first information Da can be stored in the frame memory included in the first driver 15a, and the second information Db can be stored in the frame memory included in the second driver 15b. Note that the frame memory can only store information for one frame, and the stored contents are updated for each frame supplied to the display unit 14. The storage history in the frame memory is preferably configured to be stored in the storage unit 32 of the control unit 11.

  The display unit 14 includes a plurality of pixel units 20 arranged in a matrix. The pixel unit 20 includes a first pixel 21 and a second pixel 22. The first pixels 21 included in the plurality of pixel units 20 in the display unit 14 are all driven by the first information Da supplied from the first driver 15a. Similarly, the second pixels 22 included in the plurality of pixel units 20 in the display unit 14 are all driven by the second information Db supplied from the second driver 15b. .

  FIG. 1 shows an example in which the first pixel 21 and the second pixel 22 each have a display element corresponding to three colors of red (R), green (G), and blue (B).

  The first pixel 21 includes a display element 21R corresponding to red (R), a display element 21G corresponding to green (G), and a display element 21B corresponding to blue (B). The display element 21R, the display element 21G, and the display element 21B are display elements that utilize reflection of external light.

  The second pixel 22 includes a display element 22R corresponding to red (R), a display element 22G corresponding to green (G), and a display element 22B corresponding to blue (B). The display element 22R, the display element 22G, and the display element 22B are display elements that use light from a light source.

  The first signal Sa is a signal including a gradation value given to the first pixel 21 of the pixel unit 20. Here, the first signal Sa includes information of three gradation values given to the display element 21R, the display element 21G, and the display element 21B for each pixel unit 20.

  Further, the second signal Sb is a signal including a gradation value given to the second pixel 22 of the pixel unit 20. Here, the second signal Sb includes information of three gradation values given to the display element 22R, the display element 22G, and the display element 22B for each pixel unit 20.

  Each of the signal Sa and the signal Sb may be a serial signal transmitted through a single signal line, or may be a parallel signal transmitted through a plurality of signal lines.

  The control unit 11 selects any one of a first mode, a second mode, and a third mode, which will be described later, and generates a first signal Sa and a second signal Sb based on each mode, It has a function of outputting to the drive unit 13.

  Here, for example, a microprocessor such as a GPU (Graphics Processing Unit) can be used as the calculation unit 31. These microprocessors may be configured by PLD (Programmable Logic Device) such as FPGA (Field Programmable Gate Array) and FPAA (Field Programmable Analog Array).

  At this time, the video signal S0 may be generated by a central processing unit (CPU) provided separately from the display device 10 and supplied to the control unit 11. Alternatively, the calculation unit 31 may also serve as a CPU, and the calculation unit 31 may have a function of generating the video signal S0.

  The video signal S0 input from the outside may be a signal that has been corrected in advance, such as gamma correction, or the calculation unit 31 may have a function of performing the correction. The calculation unit 31 may generate the first signal Sa and the second signal Sb based on a signal obtained by correcting the video signal S0, or the generated first signal Sa and second signal. You may correct | amend with respect to each of Sb.

  The calculation unit 31 performs various data processing and program control by interpreting and executing instructions from various programs by a processor. The program that can be executed by the processor may be stored in a memory area of the processor, or may be stored in a different memory.

  The computing unit 31 may have a main memory. The main memory may include a volatile memory such as a RAM (Random Access Memory) and a nonvolatile memory such as a ROM (Read Only Memory).

  For example, a DRAM (Dynamic Random Access Memory) is used as the RAM, and a memory space is virtually allocated and used as a work space of the arithmetic unit 31. An operating system, application programs, program modules, program data, and the like stored in an external storage device are loaded into the RAM for execution. These data, programs, and program modules loaded in the RAM are directly accessed and operated by the arithmetic unit 31.

  The control unit 11 can be mounted on a circuit board such as a printed circuit board, and the drive unit 13 can be provided on a substrate on which the display unit 14 is formed. At this time, the circuit board and the drive unit 13 may be connected via an FPC (Flexible Print Circuit) or the like. Further, at this time, the driving unit 13 may be formed on the substrate on which the display unit 14 is formed in the same process as the transistors constituting the display unit 14, or a part or all of the driving unit 13 is an IC. It may be mounted on the substrate as (Integrated Circuit). Or you may mount the control part 11 and the drive part 13 on the said board | substrate as a form of 1 or several IC. Or the control part 11 and the drive part 13 may be formed in the same process as the transistor etc. which comprise the display part 14 in the board | substrate with which the display part 14 was formed.

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

<Configuration example of pixel unit>
Subsequently, the pixel unit 20 will be described with reference to FIGS. 2A to 2C are schematic diagrams illustrating a configuration example of the pixel unit 20.

  The first pixel 21 includes a display element 21R, a display element 21G, and a display element 21B. The display element 21 </ b> R reflects external light and emits red light R <b> 1 having a luminance corresponding to the gradation value corresponding to red included in the first gradation value input to the first pixel 21 on the display surface side. To ejaculate. Similarly, the display element 21G and the display element 21B respectively emit green light G1 and blue light B1 to the display surface side.

  The second pixel 22 includes a display element 22R, a display element 22G, and a display element 22B. The display element 22R has a light source, and emits red light R2 having a luminance corresponding to the gradation value corresponding to red included in the second gradation value input to the second pixel 22 on the display surface side. Eject. Similarly, the display element 22G and the display element 22B respectively emit green light G2 and blue light B2 to the display surface side.

[First mode]
FIG. 2A shows an example of an operation mode (first mode) in which an image is displayed by driving the display element 21R, the display element 21G, and the display element 21B that reflect external light (visible light). The first mode is an operation mode that is effective when applied, for example, when the illuminance of outside light is sufficiently high. As shown in FIG. 2A, in the first mode, only the light from the first pixel 21 (light R1, light G1, and light B1 visible light) is used without using the second pixel 22. As a result, the light 25 of a predetermined color is emitted to the display surface side. Since the first mode uses the illuminance of outside light and does not require a light source, display with extremely low power consumption is possible compared to the second mode described later.

[Second mode]
FIG. 2B shows an example of an operation mode (second mode) in which an image is displayed by driving the display element 22R, the display element 22G, and the display element 22B that emit light (visible light). The second mode is an operation mode that is effective when applied, for example, when the illuminance of outside light is extremely small. As shown in FIG. 2B, in the second mode, only the light from the second pixel 22 (light R2, light G2, and light B2 visible light) is used without using the first pixel 21. As a result, the light 25 of a predetermined color is emitted to the display surface side. The second mode can display more vividly than the first mode described above. In addition, by reducing the luminance in accordance with the small illuminance of external light, it is possible to suppress glare that the user feels and to reduce power consumption.

[Third mode]
FIG. 2C illustrates the display element 21R, the display element 21G, and the display element 21B that reflect external light (visible light), and the display element 22R, the display element 22G, and the display element 22B that themselves emit light (visible light). An example of an operation mode (third mode) in which both are driven to display an image is shown. The third mode is an operation mode that is effective when the illuminance of outside light is relatively low, such as under room lighting or in the morning or evening hours, or when the chromaticity of the outside light is not white. . As shown in FIG. 2C, in the third mode, the pixel unit 20 mixes six lights (visible light) of light R1, light G1, light B1, light R2, light G2, and light B2. As a result, the light 25 of a predetermined color is emitted to the display surface side. The third mode can display more vividly than the first mode described above, and can display with lower power consumption than the second mode described above. In the third mode, the ratio of the reflected light (visible light) from the first pixel 21 and the light emission (visible light) from the second pixel is appropriately adjusted according to the use environment of the display device 10. Therefore, it is possible to provide a display that is easy for the user to see and is easy on the eyes in any environment.

  The above is the description of the configuration example of the pixel unit 20.

<Operation Example 1 of Display Device>
Hereinafter, specific operation examples of the display device 10 of one embodiment of the present invention will be described in detail.

[Flowchart 1 (routine)]
FIG. 3 is a flowchart illustrating an operation example of the display device 10 of one embodiment of the present invention. The flowchart shows a driving method for avoiding or reducing the occurrence of display burn-in by continuously displaying the same character or image on the second pixel 22 of the display unit 14 for a long time.

  First, in step X0, the initial display of the display unit 14 is set. Step X0 corresponds to a step of performing an initial display on the display unit 14, for example, when the display device 10 is turned on from a power-off state. At this stage, what characters and images are displayed on the display unit 14, and what operation mode (first mode, second mode, or third mode) they are displayed on, Any initial setting such as can be arbitrarily performed by the control unit 11. Therefore, at step X0, the operation mode of the display unit 14 may be any of the first mode, the second mode, and the third mode. Different operation modes may be mixed depending on the plane of the display unit 14. For example, when the display unit 14 according to one embodiment of the present invention is a display of a smartphone, a menu icon unit, a status bar unit (displays battery remaining amount, radio wave intensity, etc.), or a display unit of date / time Is displayed in the first mode or the third mode from the beginning because it takes a long time to display in the same place on the display surface, and the other display places are displayed in the second mode. Etc.

  Next, in step X1, it is determined whether or not the external light illuminance is equal to or less than a “constant value”. Here, the illuminance of outside light is detected by the photometry unit 12, and the information is supplied to the control unit 11. Then, the calculation unit 31 included in the control unit 11 determines whether or not the external light illuminance is equal to or less than a “constant value”. The “constant value” is a value that can be arbitrarily set by the control unit 11.

  In step X1, when the determination result is affirmative (external light illuminance is “a certain value” or less), the process proceeds to step X2. In step X <b> 2, part or all of the display unit 14 is displayed by the second pixels 22. That is, a part or all of the display unit 14 is displayed in the second mode. Here, a part of the display unit 14 is a part that is highly likely to be displayed for a long time at the same part in the surface of the display unit 14 (for example, in the case of the smartphone described above, the icon part of the menu, the status bar part, Or the area excluding the date and time display part). Thus, even in an environment where the illuminance of outside light is low, such as at night or in a dark room, the display luminance of the display unit 14 is emitted by the light emission of the display elements (display element 22R, display element 22G, display element 22B) included in the second pixel 22. It is possible to provide an image that is easy for the user to see. In addition, the display of the second pixel 22 is performed in the first mode or the third mode for a portion that is likely to be displayed for a long time at the same portion of the display surface 14 described above. It is possible to suppress wear and deterioration of the elements (display element 22R, display element 22G, display element 22B), and to reduce or avoid the occurrence of display burn-in at the location. After step X2, the process proceeds to step X3 (described later).

  In Step X1, when the determination result is negative (external light illuminance is “a certain value” or more), the process proceeds to Step X3. In step X3, it is determined whether or not the second information Db supplied to the display unit 14 has not passed through the frame memory of the second driver 15b, that is, whether or not there is a history stored in the frame memory.

  In step X3, if the determination result is affirmative (the second information Db has not passed through the frame memory and there is no history stored in the frame memory), the process proceeds to step X4 (described later).

  In step X3, if the determination result is negative (the second information Db passes through the frame memory and there is a history stored in the frame memory), the process proceeds to step X5 (described later).

  In step X4 described above, it is determined whether part or all of the display on the display unit 14 is unchanged. Here, whether or not a part or all of the display is unchanged is determined based on the second information Db currently stored in the frame memory and the second information stored in the frame memory one frame before. Whether or not the information Db is the same is performed. The determination can be made by the control unit 11 based on the storage history of the frame memory stored in the storage unit 32.

  In step X4, if the determination result is affirmative (the stored second information Db is the same between the current and the previous frame), the process proceeds to step X5 (described later).

  In step X4, if the determination result is negative (the stored second information Db is different between the current and the previous frame), the process proceeds to step X6 (described later).

  In step X5 described above, the display on the second pixel 22 is stopped and the display on the first pixel 21 is performed in part or all of the display unit 14. Here, a part of the display unit 14 is a part that is highly likely to be displayed for a long time at the same part in the surface of the display unit 14 (for example, in the case of the smartphone described above, the icon part of the menu, the status bar part, Or the area excluding the date and time display part). For the region, display using only the first pixel 21 is performed in advance. By doing so, it is possible to reduce display burn-in caused by wear and deterioration of the display elements (display element 22R, display element 22G, and display element 22B) included in the second pixel 22 on the entire surface of the display unit 14 or It can be avoided. In addition, by switching to an operation mode (first mode) using only the first pixel, as compared with a case where display is performed in an operation mode (second mode or third mode) using the second pixel, A display with low power consumption can be realized. After step X5, the process returns to step X1 described above again.

  In Step X6 described above, a part or all of the display unit 14 is displayed by the second pixel 22 (the same processing as Step X2). Here, a part of the display unit 14 is a part that is highly likely to be displayed for a long time at the same part in the surface of the display unit 14 (for example, in the case of the smartphone described above, the icon part of the menu, the status bar part, Or the area excluding the date and time display part). In addition, about the said area | region, when the display was performed in the operation mode (1st mode) using only the 1st pixel 21 previously, the operation mode (2nd mode or 3rd) using the 2nd pixel 22 is used. Mode), or the first mode may be continued as it is. For this region, the operation mode (second mode or third mode) using the second pixel 22 is continued. In this way, since the operation mode does not switch between frames, it is possible to provide the user with a smooth image whose appearance does not change with time. In addition, after step X6, it returns to step X1 demonstrated above again.

  As described above, by repeating the series of steps from Step X1 to Step X6, the display device 10 of one embodiment of the present invention can display the entire surface of the display portion 14 regardless of the use environment even when displaying for a long time. In this case, it is possible to reduce or avoid the occurrence of display burn-in caused by the consumption / deterioration of the display elements (display element 22R, display element 22G, display element 22B) included in the second pixel 22.

[Flowchart 2 (Subroutine)]
In the operation of the display device 10 of one embodiment of the present invention, a flow for giving a delay may be provided for the determination (for example, step X1 or step X4) in the flowchart shown in FIG. Below, the specific example of the said flow is demonstrated.

  FIG. 4 shows an example of a flowchart applicable to step X1 or step X4 as a subroutine of the flowchart shown in FIG. FIG. 4 is a flow for giving a delay to the determination (step X1 or step X4) in the flowchart shown in FIG.

  First, in step Y1, a process of setting the number n of executions of determination in step X1 (step X4) of the flowchart shown in FIG. Step Y1 is preferably configured to be executed in step X0 (step X3), which is the previous stage of step X1 (step X4).

  Next, at step Y2, a determination is made based on step X1 (step X4) of the flowchart shown in FIG. For the details of the determination contents of step X1 (step X4), the above-described explanation contents are taken into consideration.

  If the determination result is affirmative in step Y2, the process proceeds to step Y3. In step Y3, a process of setting the number of executions of the determination in step X1 (step X4) to a value that is increased by one from the cumulative number of executions so far (for example, once when passing through step Y3 for the first time) is performed. . After step Y3, the process proceeds to step Y4 (described later).

  If the determination result is negative in step Y2, the process proceeds to step Y6. In step Y6, the process which progresses to step X3 (step X6) of the flowchart shown in FIG. 3 is performed. For the details of the contents of step X3 (step X6), the above-described explanation content is taken into consideration.

  In step Y4 described above, it is determined whether or not the number n of executions of determination in step X1 (step X4) in the flowchart shown in FIG. 3 exceeds the upper limit value N (N is an integer equal to or greater than 1). Note that the upper limit value N is preferably set arbitrarily by the control unit 11.

  If the determination result is affirmative (n ≧ N) in step Y4, the process proceeds to step Y5. In step Y5, a process of proceeding to step X2 (step X5) of the flowchart shown in FIG. 3 is performed. For the details of the contents of step X2 (step X5), the above-described explanation content is referred to.

  In step Y4, when the determination result is negative (n <N), the process returns to step Y2 described above. Regarding the flow after step Y2, the above-described explanation can be taken into consideration.

  As described above, an aspect of the present invention is provided by providing a flow such as the above-described steps Y1 to Y6 with respect to the determination (for example, step X1 or step X4) in the flowchart illustrated in FIG. The display device 10 includes display elements (display element 22R, display element 22G, display element 22B) included in the second pixel 22 over the entire surface of the display unit 14 regardless of the use environment, even when displaying for a long time. It is possible to reduce or avoid the occurrence of image burn-in due to wear and deterioration.

[Operation example of display section (change in display brightness over time)]
As described above, the display device 10 of one embodiment of the present invention can drive the display portion 14 in three types of operation modes (a first mode, a second mode, and a third mode). For example, in the flowchart shown in FIG. 3, the various operation modes can be applied to Step X2, Step X5, and Step X6. Hereinafter, a specific operation example of the display unit 14 in step X5 of the flowchart shown in FIG. 3 will be described.

  FIGS. 5A to 5E are diagrams schematically illustrating an operation example when the display unit 14 is displayed by the first pixel 21 and / or the second pixel 22 as a change in display luminance over time. It is. 5A to 5E, the horizontal axis represents time, and the vertical axis represents the display luminance of each pixel (the first pixel 21 and the second pixel 22). FIG. 5A shows an operation example in the case where display (second mode) is continued with only the second pixel 22 over time. A solid line in the drawing represents the display luminance of the second pixel 22. FIG. 5A is an operation example of the display unit 14 at the time of determination in step X4, which is a stage before step X5 and step X6. FIG. 5B is an operation example in the case where display (first mode) is continued with only the first pixel 21 over time. A broken line in the figure represents the display luminance of the first pixel 21. FIG. 5B is one example of an operation that can be applied to step X5.

  An example of the operation of the display unit 14 applicable to step X5 is not limited to that shown in FIG. FIG. 5C to FIG. 5E are also examples of the operation of the display unit 14 that can be applied to step X5. FIG. 5C is an operation example in which display on the first pixel 21 (first mode) and display on the second pixel 22 (second mode) are alternately performed. The figure shows an example in which the period T1 and the period T3 are displayed by the first pixel 21 (first mode), and the period T2 and the period T4 are displayed by the second pixel 22 (second mode). . With such an operation, the display time of the second pixel 22 can be shortened as compared with the operation in FIG. 5A. Therefore, the display element (the display element 22R, the display element) included in the second pixel 22 can be shortened. It is possible to reduce wear and deterioration of the element 22G and the display element 22B). Note that the control unit 11 arbitrarily sets the length of the period for displaying the first pixel 21 (period T1, period T3, etc.) and the period for displaying the second pixel 22 (period T2, period T4, etc.). Preferably it can be done.

  FIG. 5D shows an operation example in which display (third mode) is continued on both the first pixel 21 and the second pixel 22 over time. Compared with the display brightness of the second pixel 22 shown in FIG. 5A, the display brightness of the first pixel 21 and the second pixel shown in FIG. With such an operation, the display luminance of the second pixel 22 can be reduced as compared with the operation in FIG. 5A. Therefore, the display element (the display element 22R, the display element) included in the second pixel 22 can be reduced. It is possible to reduce wear and deterioration of the element 22G and the display element 22B). In addition, it is preferable that the display luminance of the first pixel 21 and the display luminance of the second pixel 22 can be arbitrarily set by the control unit 11.

  In FIG. 5E, the first pixel 21 continues to display (first mode) over time, and the second pixel 22 displays only for a certain period (period T2, period T4, etc.) This is an example of operation. With such an operation, the display time of the second pixel 22 can be shortened and the display luminance can be reduced as compared with the operation of FIG. Consumption and deterioration of the display elements (display element 22R, display element 22G, display element 22B) included in the display can be reduced. Note that it is preferable that the control unit 11 can arbitrarily set the length and display luminance of the period for displaying the second pixel 22 (period T2, period T4, etc.) and the display luminance of the first pixel 21.

  In the above, FIGS. 5B to 5E have been described as the operation example of the display unit 14 in step X5 of the flowchart shown in FIG. 3, but the same applies to step X6 (step X2 of the flowchart shown in FIG. 3). .) Is also applicable as an example of operation. However, in this case, the relationship between the display luminance of the first pixel 21 and the display luminance of the second pixel 22 in FIGS. 5B to 5E is switched.

  As described above, one or more of the various operation examples described above can be applied to the display device 10 of one embodiment of the present invention. Thereby, it is possible to avoid or reduce the occurrence of display burn-in by continuously displaying the same character or image on the second pixel 22 of the display unit 14 for a long time.

<Operation Example 2 of Display Device>
The operation example of the display device 10 of one embodiment of the present invention is not limited to the above-described example. Hereinafter, an operation example different from the above-described example will be described.

  In the operation example described below, unlike the example described above, the first driver 15a and the first driver 15b do not have to include a frame memory.

  Note that the operation example described below is based on the assumption that the display unit 14 operates in the second mode or the third mode described above. That is, it is assumed that the display unit 14 has a region displaying using the second pixel 22 in the same plane.

  In one aspect of the present invention, when the control unit 11 supplies the second signal Sb to the second driver 15b included in the drive unit 13, the storage unit 32 included in the control unit 11 outputs the second signal Sb. You may have the function to memorize.

  At this time, the storage unit 32 may store the second signal Sb supplied to the second driver 15b as it is, or an integrated value including the second signal Sb supplied to the second driver 15b in the past. May be stored as The calculation unit 31 performs the process of converting the integral value.

  The second signal Sb or the integrated value of the second signal Sb stored in the storage unit 32 (hereinafter collectively referred to as “display information”) is “corrected” by the calculation unit 31. The new second signal Sb is supplied to the second driver 15b. Here, the “correction” specifically refers to the display unit 14 that is inverted with respect to the display information (including the luminance distribution in the display unit 14 surface) supplied to the second driver 15b. This refers to processing for generating display information having an in-plane luminance distribution. For example, in the display information supplied to the second driver 15b, a location where the luminance is high in the display unit 14 surface is reset to display information with a low luminance by the correction, and a location where the luminance is low in the display unit 14 surface. Is reset to display information with high luminance by the correction.

[Example of display information before and after correction]
6A and 6B show an example of display information before and after correction supplied from the control unit 11 to the second driver 15b. FIG. 6A shows display information on the display unit 14 in a certain display period (before “correction”). In the display information shown in FIG. 6A, white portions and black portions are distributed in a staggered pattern in the surface of the display portion 14. Here, the white part is a part having display information whose luminance is higher than the reference value, and the black part is a part having display information whose luminance is lower than the reference value. Here, the reference value is an arbitrary luminance value that can be set by the control unit 11. As described above, the display information is stored in the storage unit 32. Here, it is assumed that the display information shown in FIG. 6A stores only display information for a certain display period in the storage unit 32 as it is, not as an integrated value including past display information. .

  The display information of the display unit 14 in a certain display period shown in FIG. 6A is stored in the storage unit 32, and the above-described “correction” is applied by the calculation unit 31.

  FIG. 6B shows display information on the display unit 14 after “correction”. By applying “correction”, the portion (white portion) having display information with high luminance in FIG. 6A is changed to display information with low luminance (black) in FIG. 6B. In FIG. 6 (A), the portion having the display information with low luminance (black portion) is changed to the display information with high luminance (white) in FIG. 6 (B).

  In this way, the control unit 11 applies the above-described “correction” to the display information (FIG. 6A) on the display unit 14 in a certain display period, and in the next display period, it is inverted from FIG. By supplying the display information having the in-plane distribution of display luminance (FIG. 6B) to the second driver 15b, the in-plane distribution of the display information with respect to the time axis can always be leveled.

  6A and 6B show display examples in which places having high luminance display information (white places) and places having low display information (black places) are distributed in a staggered pattern. However, the present invention is not limited to this, and a distribution other than a staggered pattern or a random distribution may be used.

  Further, in FIGS. 6A and 6B, there are only two gradations, a portion having display information with higher luminance than an arbitrary reference value (white portion) and a portion having low display information (black portion). However, one embodiment of the present invention is not limited to this, and the gradation of display information may be further divided. In this case as well, the display information having the in-plane distribution information of the display luminance reversed to the display information having the in-plane distribution information of the display luminance in a certain display period is supplied to the next display period to Display information for the axis can be leveled in the plane. The control unit 11 can arbitrarily set how finely the gradation of the display information is divided.

  6A and 6B, the display information of the display unit 14 is displayed by being divided into 32 planes (4 rows × 8 columns). However, one embodiment of the present invention is not limited to this. Absent. The number of divisions in the plane can be subdivided according to the number of pixels of the display unit 14.

  In addition, the display device 10 of one embodiment of the present invention can include a photometric unit 12 that detects external light information (illuminance). Therefore, the display device 10 of one embodiment of the present invention may have a function of switching display elements used for display on the display unit 14 in accordance with the external light illuminance detected by the photometry unit 12.

  For example, it is assumed that the display unit 14 is operating in the second mode or the third mode described above. That is, it is assumed that the display unit 14 has a region that is displayed using the second pixel 22 in the same plane.

  The photometry unit 12 can detect external light information (illuminance) and supply the external light information to the calculation unit 31 included in the control unit 11.

  When the external light information (illuminance) received by the calculation unit 31 from the photometry unit 12 is higher than the “constant value”, the calculation unit 31 causes the drive unit 13 to receive the first signal Sa including display information in the next display period. It supplies to the 1st driver 15a which has. As described above, the “constant value” is a value that can be arbitrarily set by the control unit 11.

  At this time, it is preferable that the second signal Sb including the display information in the next display period is always supplied to the second driver 15b. However, only the first information Da from the first driver 15a is supplied from the driving unit 13 to the display unit 14, and the second information Db from the second driver 15b is supplied to the display unit 14. Shall not be supplied.

  As described above, the first information Da supplied from the first driver 15 a is information for driving the first pixels 21 included in the pixel unit 20 in the display unit 14. Therefore, in the next display period in which the photometry unit 14 detects external light illuminance (higher than “a certain value”), the display unit 14 performs display using only the first pixels 21.

  As described above, the first pixel 21 has a display element (display element 21R, display element 21G, display element 21B) that reflects external light (visible light) and performs display in the first mode. is there. Therefore, as described above, when the external light illuminance is higher than the “constant value”, the light source is switched by switching the operation mode of the display unit 14 from the second mode or the third mode to the first mode. An extremely low power consumption display that is not used can be performed.

  As described above, the second signal Sb including the display information in the next display period is also configured to always supply the latest information “corrected” from the control unit 11 to the second driver 15b. For example, at a certain timing, the ambient light illuminance changes from a state higher than “a certain value” to a lower state, and the operation mode of the display unit 14 is switched from the first mode to the second mode or the third mode. However, the second information Db set in the optimum state can be immediately supplied to the display unit 14.

  As described above, in the display device 10 of one embodiment of the present invention, when the external light illuminance is higher than the “constant value”, the operation mode of the display unit 14 is changed from the second mode or the third mode to the first mode. By switching to the mode, display with extremely low power consumption without using a light source can be performed. At this time, for the second signal Sb that does not directly contribute to the display, the latest display information “corrected” from the control unit 11 is always supplied to the second driver 15b. When the external light illuminance changes to a state lower than the “constant value”, the second information Db set to the optimum state can be immediately supplied to the display unit 14. That is, since the control unit 11 can continuously supply the display information with the in-plane luminance distribution leveled to the second driver 15b, the light emitting display element (display element 22R, It is possible to suppress the display element 22G and the display element 22B) from being locally consumed and deteriorated in the surface of the display unit 14, and to avoid or reduce the occurrence of display burn-in.

  This embodiment can be implemented in appropriate combination with at least part of the other embodiments described in this specification.

(Embodiment 2)
Examples of display panels that can be used for the display portion of the display device of one embodiment of the present invention are described below. The display panel exemplified below is a display panel that includes both a reflective liquid crystal element and a light-emitting element and can perform both transmission mode and reflection mode displays.

<Configuration example>
FIG. 7A is a block diagram illustrating an example of a structure of the display device 400. The display device 400 includes a plurality of pixels 410 arranged in a matrix on the display portion 362. The display device 400 includes a circuit GD and a circuit SD. In addition, a plurality of pixels 410 arranged in the direction R, and 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 circuit GD are provided. In addition, the pixel 410 includes a plurality of pixels 410 arranged in the direction C, and a plurality of wirings S1 and a plurality of wirings S2 that are electrically connected to the circuit SD.

  Note that the display device 400 illustrated in FIG. 7A corresponds to the driving unit 13 and the display unit 14 in the display device 10 illustrated in FIG. 1.

  Here, for the sake of simplicity, a configuration having one circuit GD and one circuit SD is shown, but a circuit GD and a circuit SD that drive a liquid crystal element, and a circuit GD and a circuit SD that drive a light-emitting element, It 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 that overlap each other.

  FIG. 7B1 illustrates a configuration example of the electrode 311b included in the pixel 410. The electrode 311b functions as a reflective electrode of the liquid crystal element in the pixel 410. In addition, an opening 451 is provided in the electrode 311b.

  In FIG. 7B1, the light-emitting element 360 located in a region overlapping with the electrode 311b is indicated by a broken line. The light-emitting element 360 is disposed so as to overlap with the opening 451 included in the electrode 311b. Thereby, the light emitted from the light emitting element 360 is emitted to the display surface side through the opening 451.

  In FIG. 7B1, the pixels 410 adjacent in the direction R indicate pixels corresponding to different colors. At this time, as shown in FIG. 7B1, in two pixels adjacent to the direction R, it is preferable that the openings 451 are provided at different positions of the electrode 311b so as not to be arranged in a line. Accordingly, the two light-emitting elements 360 can be separated from each other, and a phenomenon (also referred to as crosstalk) in which light emitted from the light-emitting elements 360 enters the colored layer of the adjacent pixel 410 can be suppressed. In addition, since the two adjacent light emitting elements 360 can be arranged apart from each other, a display device with high definition can be realized even when the EL layer of the light emitting element 360 is separately formed by a shadow mask or the like.

  Further, the electrodes 311b may be arranged as shown in FIG.

  If the ratio of the total area of the openings 451 to the total area of the non-openings is too large, the display using the liquid crystal element becomes dark. If the ratio of the total area of the openings 451 to the total area of the non-openings is too small, the display using the light emitting element 360 is darkened.

  In addition, when the area of the opening 451 provided in the electrode 311b functioning as the reflective electrode is too small, the efficiency of light that can be extracted from the light emitted from the light-emitting element 360 is reduced.

  The shape of the opening 451 can be, for example, a polygon, a rectangle, an ellipse, a circle, a cross, or the like. Moreover, it is good also as an elongated streak shape, a slit shape, and a checkered shape. Further, the opening 451 may be arranged close to adjacent pixels. Preferably, the opening 451 is arranged close to other pixels displaying the same color. Thereby, crosstalk can be suppressed.

<Circuit configuration example>
FIG. 8 is a circuit diagram illustrating a configuration example of the pixel 410. In FIG. 8, two adjacent pixels 410 are shown.

  The pixel 410 includes a switch SW1, a capacitor C1, a liquid crystal element 340, a switch SW2, a transistor M, a capacitor C2, a light emitting element 360, and the like. In addition, a wiring G1, a wiring G2, a wiring ANO, a wiring CSCOM, a wiring S1, and a wiring S2 are electrically connected to the pixel 410. In FIG. 8, a wiring VCOM1 electrically connected to the liquid crystal element 340 and a wiring VCOM2 electrically connected to the light emitting element 360 are illustrated.

  FIG. 8 shows an example in which transistors are used for the switch SW1 and the switch SW2.

  The switch SW1 has a gate connected to the wiring G1, a source or drain connected to the wiring S1, and the other source or drain connected to one electrode of the capacitor C1 and one electrode of the liquid crystal element 340. Yes. The other electrode of the capacitor C1 is connected to the wiring CSCOM. The other electrode of the liquid crystal element 340 is connected to the wiring VCOM1.

  The switch SW2 has a gate connected to the wiring G2, one of the source and the drain connected to the wiring S2, and the other of the source and the drain connected to one electrode of the capacitor C2 and the gate of the transistor M. . The other electrode of the capacitor C2 is connected to one of the source and the 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. The other electrode of the light emitting element 360 is connected to the wiring VCOM2.

  FIG. 8 shows an example in which the transistor M has two gates sandwiching a semiconductor forming a channel region and these are connected. As a result, the current that can be passed by the transistor M can be increased.

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

  A signal for controlling the switch SW2 to be in a conductive state or a non-conductive state can be supplied to the wiring G2. The wiring VCOM2 and the wiring ANO can each be supplied with a potential at which a potential difference generated by the light emitting element 360 emits light. A signal for controlling the conduction state of the transistor M can be supplied to the wiring S2.

  For example, in the case of performing reflection mode display, the pixel 410 illustrated in FIG. 8 is driven by a signal supplied to the wiring G1 and the wiring S1, and can display using optical modulation by the liquid crystal element 340. In the case where display is performed in the transmissive mode, display can be performed by driving the light-emitting element 360 by driving with signals supplied to the wiring G2 and the wiring S2. In the case where display is performed in both modes, the display can be driven by signals given to the wiring G1, the wiring G2, the wiring S1, and the wiring S2.

  Note that although FIG. 8 illustrates an example in which one pixel 410 includes one liquid crystal element 340 and one light emitting element 360, the present invention is not limited thereto. FIG. 9A illustrates an example in which one pixel 410 includes one liquid crystal element 340 and four light-emitting elements 360 (light-emitting element 360r, light-emitting element 360g, light-emitting element 360b, and light-emitting element 360w). A pixel 410 illustrated in FIG. 9A is a pixel capable of full color display with one pixel, unlike FIG.

  In FIG. 9A, in addition to the example of FIG. 8, a wiring G3 and a wiring S3 are connected to the pixel 410.

  In the example shown in FIG. 9A, for example, four light-emitting elements 360 (light-emitting element 360r, light-emitting element 360g, light-emitting element 360b, and light-emitting element 360w) are red (R), green (G), and blue (B ) And a white light-emitting element (W) can be used. As the liquid crystal element 340, a reflective liquid crystal element exhibiting white can be used. Thereby, when displaying in reflection mode, white display with high reflectance can be performed. In addition, when display is performed in the transmissive mode, display with high color rendering properties can be performed with low power.

  FIG. 9B illustrates a configuration example of the pixel 410. The pixel 410 includes a light-emitting element 360 w that overlaps with an opening included in the electrode 311, and a light-emitting element 360 r, a light-emitting element 360 g, and a light-emitting element 360 b that are disposed around the electrode 311. The light emitting element 360r, the light emitting element 360g, and the light emitting element 360b preferably have substantially the same light emitting area.

<Configuration example of display panel>
FIG. 10 is a schematic perspective view of the display panel 100 of one embodiment of the present invention. The display panel 100 has a configuration in which a substrate 51 and a substrate 61 are bonded together. In FIG. 10, the substrate 61 is clearly indicated by a broken line.

  The display panel 100 includes a display unit 62, a circuit 64, a wiring 65, and the like. The substrate 51 is provided with, for example, a circuit 64, a wiring 65, and a conductive layer 111b that functions as a pixel electrode. FIG. 10 shows an example in which the IC 73 and the FPC 72 are mounted on the substrate 51. Therefore, the structure illustrated in FIG. 10 can be said to be a display module including the display panel 100, the FPC 72, and the IC 73.

  As the circuit 64, for example, a circuit functioning as a scan line driver circuit can be used.

  The wiring 65 has a function of supplying a signal and power to the display unit 62 and the circuit 64. The signal and power are input to the wiring 65 from the outside via the FPC 72 or from the IC 73.

  FIG. 10 shows an example in which the IC 73 is provided on the substrate 51 by a COG (Chip On Glass) method or the like. As the IC 73, for example, an IC having a function as a scan line driver circuit or a signal line driver circuit can be applied. Note that when the display panel 100 includes a circuit that functions as a scan line driver circuit and a signal line driver circuit, or a circuit that functions as a scan line driver circuit or a signal line driver circuit is provided outside, the display panel 100 is connected via the FPC 72. In the case of inputting a signal for driving, the IC 73 may not be provided. Further, the IC 73 may be mounted on the FPC 72 by a COF (Chip On Film) method or the like.

  FIG. 10 shows an enlarged view of a part of the display unit 62. In the display portion 62, conductive layers 111b included in a plurality of display elements are arranged in a matrix. The conductive layer 111b has a function of reflecting visible light and functions as a reflective electrode of the liquid crystal element 40 described later.

  As shown in FIG. 10, the conductive layer 111b has an opening. Further, the light-emitting element 60 is provided on the substrate 51 side of the conductive layer 111b. Light from the light emitting element 60 is emitted to the substrate 61 side through the opening of the conductive layer 111b.

<Cross-section configuration example>
FIG. 11 illustrates an example of a cross section of the display panel 100 illustrated in FIG. 10 when a part of the region including the FPC 72, a part of the region including the circuit 64, and a part of the region including the display unit 62 are cut. Indicates.

  The display panel 100 includes an insulating layer 220 between the substrate 51 and the substrate 61. In addition, the light-emitting element 60, the transistor 201, the transistor 205, the transistor 206, the coloring layer 134, and the like are provided between the substrate 51 and the insulating layer 220. In addition, the liquid crystal element 40, the coloring layer 131, and the like are provided between the insulating layer 220 and the substrate 61. The substrate 61 and the insulating layer 220 are bonded via an adhesive layer 141, and the substrate 51 and the insulating layer 220 are bonded via an adhesive layer 142.

  The transistor 206 is electrically connected to the liquid crystal element 40, and the transistor 205 is electrically connected to the light emitting element 60. Since both the transistor 205 and the transistor 206 are formed over the surface of the insulating layer 220 on the substrate 51 side, they can be manufactured using the same process.

  The substrate 61 is provided with a colored layer 131, a light shielding layer 132, an insulating layer 121, a conductive layer 113 functioning as a common electrode of the liquid crystal element 40, an alignment film 133b, an insulating layer 117, and the like. The insulating layer 117 functions as a spacer for maintaining the cell gap of the liquid crystal element 40.

  Insulating layers such as an insulating layer 211, an insulating layer 212, an insulating layer 213, an insulating layer 214, and an insulating layer 215 are provided on the substrate 51 side of the insulating layer 220. A part of the insulating layer 211 functions as a gate insulating layer of each transistor (the transistor 201, the transistor 205, and the transistor 206). The insulating layer 212, the insulating layer 213, and the insulating layer 214 are provided to cover the transistors (the transistor 201, the transistor 205, and the transistor 206). An insulating layer 215 is provided to cover the insulating layer 214. The insulating layer 214 and the insulating layer 215 function as a planarization layer. Note that although the case where the insulating layer covering the transistor and the like has three layers of the insulating layer 212, the insulating layer 213, and the insulating layer 214 is shown here, the invention is not limited thereto, and four or more layers may be used. It may be a single layer or two layers. In addition, the insulating layer 214 functioning as a planarization layer is not necessarily provided if not necessary.

  The transistor 201, the transistor 205, and the transistor 206 include a conductive layer 221 that partially functions as a gate, a conductive layer 222 that partially functions as a source or a drain, and a semiconductor layer 231. Here, the same hatching pattern is given to a plurality of layers obtained by processing the same conductive film.

  The liquid crystal element 40 is a reflective liquid crystal element. The liquid crystal element 40 has a structure in which a conductive layer 111a, a liquid crystal 112, and a conductive layer 113 are stacked. In addition, a conductive layer 111b that reflects visible light is provided in contact with the substrate 51 side of the conductive layer 111a. The conductive layer 111 b has an opening 251. The conductive layer 111a and the conductive layer 113 include a material that transmits visible light. An alignment film 133 a is provided between the liquid crystal 112 and the conductive layer 111 a, and an alignment film 133 b is provided between the liquid crystal 112 and the conductive layer 113. Further, a polarizing plate 130 is provided on the outer surface of the substrate 61.

  In the liquid crystal element 40, the conductive layer 111b has a function of reflecting visible light, and the conductive layer 113 has a function of transmitting visible light. Light incident from the substrate 61 side is polarized by the polarizing plate 130, passes through the conductive layer 113 and the liquid crystal 112, and is reflected by the conductive layer 111b. Then, the light passes through the liquid crystal 112 and the conductive layer 113 again and reaches the polarizing plate 130. At this time, alignment of liquid crystal can be controlled by a voltage applied between the conductive layer 111b and the conductive layer 113, and optical modulation of light can be controlled. That is, the intensity of light emitted through the polarizing plate 130 can be controlled. Further, the light extracted outside the specific wavelength region is absorbed by the colored layer 131, so that the extracted light becomes, for example, red light.

  The light emitting element 60 is a bottom emission type light emitting element. The light-emitting element 60 has a structure in which a conductive layer 191, an EL layer 192, and a conductive layer 193b are stacked in this order from the insulating layer 220 side. In addition, a conductive layer 193a is provided so as to cover the conductive layer 193b. The conductive layer 193b includes a material that reflects visible light, and the conductive layer 191 and the conductive layer 193a include a material that transmits visible light. Light emitted from the light emitting element 60 is emitted to the substrate 61 side through the colored layer 134, the insulating layer 220, the opening 251, the conductive layer 113, and the like.

  Here, as shown in FIG. 11, the opening 251 is preferably provided with a conductive layer 111a that transmits visible light. As a result, the liquid crystal 112 is aligned in the region overlapping with the opening 251 similarly to the other regions, so that the alignment failure of the liquid crystal occurs at the boundary between these regions, thereby preventing unintended light leakage. it can.

  Here, a linearly polarizing plate may be used as the polarizing plate 130 disposed on the outer surface of the substrate 61, but a circularly polarizing plate may also be used. As a circularly-polarizing plate, what laminated | stacked the linearly-polarizing plate and the quarter wavelength phase difference plate can be used, for example. Thereby, external light reflection can be suppressed. Moreover, what is necessary is just to implement | achieve desired contrast by adjusting the cell gap, orientation, drive voltage, etc. of the liquid crystal element used for the liquid crystal element 40 according to the kind of polarizing plate.

  An insulating layer 217 is provided over the insulating layer 216 that covers the end portion of the conductive layer 191. The insulating layer 217 functions as a spacer that prevents the insulating layer 220 and the substrate 51 from approaching more than necessary. Further, in the case where the EL layer 192 and the conductive layer 193a are formed using a shielding mask (metal mask), the EL layer 192 and the conductive layer 193a have a function as a mask gapper for suppressing contact of the shielding mask with a formation surface. Also good. Note that the insulating layer 217 is not necessarily provided if not necessary.

  One of a source and a drain of the transistor 205 is electrically connected to the conductive layer 191 of the light-emitting element 60 through the conductive layer 224.

  One of a source and a drain of the transistor 206 is electrically connected to the conductive layer 111b through the connection portion 207. The conductive layer 111b and the conductive layer 111a are provided in contact with each other and are electrically connected. Here, the connection portion 207 is a portion that connects the conductive layers provided on both surfaces of the insulating layer 220 through openings provided in the insulating layer 220.

  A connection portion 204 is provided in a region of the substrate 51 that does not overlap the substrate 61. The connection unit 204 is electrically connected to the FPC 72 through the connection layer 242. The connection unit 204 has the same configuration as the connection unit 207. The upper surface of the connection portion 204 is formed using a conductive layer obtained by processing the same conductive film as the conductive layer 111a. Thereby, the connection part 204 and the FPC 72 can be electrically connected via the connection layer 242.

  A connection portion 252 is provided in a part of the region where 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 111 a and a part of the conductive layer 113 are electrically connected to each other by a connection body 243. Therefore, a signal or a potential input from the FPC 72 connected to the substrate 51 side can be supplied to the conductive layer 113 formed on the substrate 61 side through the connection portion 252.

  As the connection body 243, for example, conductive particles can be used. As the conductive particles, those obtained by coating the surface of particles such as an organic resin or silica with a metal material can be used. It is preferable to use nickel or gold as the metal material because the contact resistance can be reduced. In addition, it is preferable to use particles in which two or more kinds of metal materials are coated in layers, such as further coating nickel with gold. Further, as the connection body 243, a material that is elastically deformed or plastically deformed is preferably used. At this time, the connection body 243, which is a conductive particle, may have a shape crushed in the vertical direction, as shown in FIG. By doing so, the contact area between the connection body 243 and the conductive layer electrically connected to the connection body 243 can be increased, the contact resistance can be reduced, and the occurrence of defects such as poor connection can be suppressed.

  The connection body 243 is preferably disposed so as to be covered with the adhesive layer 141. For example, the connection body 243 may be dispersed on the adhesive layer 141 before curing.

  FIG. 11 illustrates an example in which the transistor 201 is provided as an example of the circuit 64.

  In FIG. 11, as an example of the transistor 201 and the transistor 205, a structure in which a semiconductor layer 231 where a channel region is formed is sandwiched between two gates is applied. One gate is formed of a conductive layer 221, and the other gate is formed of a conductive layer 223 that overlaps with the semiconductor layer 231 with an insulating layer 212 interposed therebetween. With such a structure, the threshold voltage of the transistor can be controlled more reliably than in the case where there is only one gate. At this time, the transistor may be driven by connecting two gates and supplying the same signal thereto. Such a transistor can increase the on-state current compared to other transistors, and can increase field-effect mobility. As a result, a circuit that can be driven at high speed can be manufactured. Furthermore, the area occupied by the circuit portion can be reduced. By applying a transistor with a large on-state current, signal delay in each wiring can be reduced even if the number of wirings is increased when the display panel 100 is increased in size or definition, and display unevenness is reduced. Can be suppressed.

  Note that the transistor included in the circuit 64 (such as the transistor 201) and the transistor included in the display portion 62 (such as the transistor 205 and the transistor 206) may have the same structure. The plurality of transistors (such as the transistor 201) included in the circuit 64 may all have the same structure, or may be a combination of transistors having different structures. In addition, the plurality of transistors (the transistor 205, the transistor 206, and the like) included in the display portion 62 may all have the same structure, or may be a combination of transistors having different structures.

  It is preferable that at least one of the insulating layer 212 and the insulating layer 213 that cover each transistor (the transistor 201, the transistor 205, the transistor 206, and the like) be formed using a material in which impurities such as water and hydrogen hardly diffuse. Accordingly, the insulating layer 212 or the insulating layer 213 can function as a barrier film. With such a structure, it is possible to effectively prevent impurities from entering the transistor from the outside, and the display panel 100 with high reliability can be realized.

  On the substrate 61 side, an insulating layer 121 is provided so as to cover the colored layer 131 and the light shielding layer 132. The insulating layer 121 may function as a planarization layer. Since the surface of the conductive layer 113 can be substantially flattened by the insulating layer 121, the alignment state of the liquid crystal 112 can be made uniform.

  An example of a method for manufacturing the display panel 100 will be described. For example, the conductive layer 111a, the conductive layer 111b, and the insulating layer 220 are formed in this order over a supporting substrate having a separation layer, and then the transistor 205, the transistor 206, the light-emitting element 60, and the like are formed, and then the substrate is formed using the adhesive layer 142. 51 and a support substrate are bonded together. Thereafter, the supporting substrate and the peeling layer are removed by peeling at the interfaces of the peeling layer and the insulating layer 220 and between the peeling layer and the conductive layer 111a. Separately, a substrate 61 on which a colored layer 131, a light shielding layer 132, a conductive layer 113 and the like are formed in advance is prepared. Then, the liquid crystal 112 is dropped on the substrate 51 or the substrate 61 and the substrate 51 and the substrate 61 are bonded to each other with the adhesive layer 141, whereby the display panel 100 can be manufactured.

  As the separation layer, a material that causes separation at the interface between the insulating layer 220 and the conductive layer 111a can be selected as appropriate. In particular, a layer including a refractory metal material such as tungsten and a layer including an oxide of the metal material are stacked as the separation layer, and silicon nitride, silicon oxynitride, or oxynitride is used as the insulating layer 220 over the separation layer. It is preferable to use a layer in which a plurality of silicon layers are stacked. When a refractory metal material is used for the separation layer, the formation temperature of a layer formed later can be increased, the impurity concentration is reduced, and the display panel 100 with high reliability can be realized.

  As the conductive layer 111a, an oxide or a nitride such as a metal oxide, a metal nitride, or a low-resistance oxide semiconductor is preferably used. In the case of using an oxide semiconductor, a material in which at least one of the concentration of hydrogen, boron, phosphorus, nitrogen, and other impurities, and the amount of oxygen vacancies is higher than that of a semiconductor layer used in a transistor is used. Can be used.

  Here, FIG. 11 shows a configuration in the case where color display is performed by the light emitting element 60 exhibiting white and the colored layer 134. In FIG. 11, the EL layer 192 is formed without being divided between adjacent pixels.

  FIG. 12 shows an example in which a light emitting element 60a exhibiting a predetermined color is applied. The light emitting element 60a is a bottom emission type light emitting element. The light-emitting element 60a has a structure in which a conductive layer 191, an EL layer 192a, and a conductive layer 193 are stacked in this order from the insulating layer 220 side. The conductive layer 193 includes a material that reflects visible light, and the conductive layer 191 includes a material that transmits visible light. Light emitted from the light emitting element 60a is emitted to the substrate 61 side through the insulating layer 220, the opening 251, the conductive layer 113, and the like. In FIG. 12, unlike the display panel 100 shown in FIG. 11, the colored layer 134 is not provided. The EL layer 192a is formed in an island shape and is divided between adjacent pixels. The EL layer 192a is formed differently so that at least the light emitting material differs between pixels of different colors. For example, for the formation of the EL layer 192a, a film formation method such as an evaporation method using a shadow mask such as a metal mask or a film formation method using a liquid material such as an inkjet method or an imprint method can be used. .

<About each component>
Hereinafter, details of each component of the display panel 100 shown above will be described.

〔substrate〕
A material having a flat surface can be used for the substrate included in the display panel 100. For the substrate from which light from the display element is extracted, a material that transmits the light is used. For example, materials such as glass, quartz, ceramic, sapphire, and organic resin can be used.

  By using a thin substrate, the display panel 100 can be reduced in weight and thickness. Further, by using a flexible substrate, the flexible display panel 100 can be realized.

  Further, since the substrate on the side from which light emission is not extracted does not have to be translucent, a metal substrate or the like can be used in addition to the above-described substrates. A metal substrate is preferable because it has high thermal conductivity and can easily conduct heat to the entire substrate, which can suppress a local temperature increase of the display panel 100. In order to obtain flexibility and bendability, the thickness of the metal substrate is preferably 10 μm to 200 μm, and more preferably 20 μm to 50 μm.

  Although there is no limitation in particular as a material which comprises a metal substrate, For example, metals, such as aluminum, copper, and nickel, aluminum alloys, or alloys, such as stainless steel, etc. can be used conveniently.

  Alternatively, a substrate that has been subjected to an insulating process by oxidizing the surface of the metal substrate or forming an insulating film on the surface may be used. For example, in addition to standing or heating in an oxygen atmosphere, an oxide film may be formed on the surface of the metal substrate by an anodic oxidation method, a coating method such as a spin coating method or a dip method, an electrodeposition method, an evaporation method. Alternatively, an insulating film may be formed over the metal substrate using a sputtering method or the like.

Examples of the material having flexibility and transparency to visible light include, for example, glass having a thickness having flexibility, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and polyacrylonitrile resin. , Polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin, cycloolefin resin, polystyrene resin, polyamideimide resin, polyvinyl chloride resin, polytetrafluoroethylene (PTFE) resin Etc. In particular, a material having a low thermal expansion coefficient is preferably used. For example, a polyamideimide resin, a polyimide resin, PET, or the like having a thermal expansion coefficient of 30 × 10 ⁻⁶ / K or less can be suitably used. Further, a substrate in which glass fiber is impregnated with an organic resin, or a substrate in which an inorganic filler is mixed with an organic resin to reduce the thermal expansion coefficient can be used. Since a substrate using such a material is light in weight, the display panel 100 using the substrate can also be reduced in weight.

  When a fibrous body is included in the material, a high-strength fiber of an organic compound or an inorganic compound is used as the fibrous body. The high-strength fiber specifically refers to a fiber having a high tensile modulus or Young's modulus, and representative examples include polyvinyl alcohol fiber, polyester fiber, polyamide fiber, polyethylene fiber, and aramid fiber. , Polyparaphenylene benzobisoxazole fiber, glass fiber, or carbon fiber. Examples of the glass fiber include glass fibers using E glass, S glass, D glass, Q glass, and the like. These may be used in the state of a woven fabric or a non-woven fabric, and a structure obtained by impregnating the fibrous body with a resin and curing the resin may be used as a flexible substrate. When a structure made of a fibrous body and a resin is used as the flexible substrate, it is preferable because reliability against breakage due to bending or local pressing is improved.

  Alternatively, glass, metal, or the like thin enough to have flexibility can be used for the substrate. Alternatively, a composite material in which glass and a resin material are bonded together with an adhesive layer may be used.

  A hard coat layer (for example, silicon nitride, aluminum oxide, etc.) that protects the surface of the display panel 100 from scratches on a flexible substrate, a layer of a material that can disperse the pressure (eg, aramid resin, etc.), etc. May be laminated. In order to suppress a decrease in the lifetime of the display element due to moisture or the like, an insulating film with low water permeability may be stacked over a flexible substrate. For example, an inorganic insulating material such as silicon nitride, silicon oxynitride, silicon nitride oxide, aluminum oxide, or aluminum nitride can be used.

  The substrate can be used by stacking a plurality of layers. In particular, when the glass layer is used, the barrier property against water and oxygen is improved, and the display panel 100 with high reliability can be obtained.

[Transistor]
The transistor includes a conductive layer that functions as a gate electrode, a semiconductor layer that forms a channel region, a conductive layer that functions as a source electrode, a conductive layer that functions as a drain electrode, and an insulating layer that functions as a gate insulating layer. Have. Note that the above shows the case where a bottom-gate transistor is used.

  Note that there is no particular limitation on the structure of the transistor included in the display device 10 of one embodiment of the present invention. For example, a planar transistor, a staggered transistor, or an inverted staggered transistor may be used. Further, a top-gate or bottom-gate transistor structure may be employed. Alternatively, gate electrodes may be provided above and below the channel region.

[Semiconductor layer]
There is no particular limitation on the crystallinity of a semiconductor material used for the transistor, and an amorphous semiconductor, a semiconductor having crystallinity (a microcrystalline semiconductor, a polycrystalline semiconductor such as polysilicon formed by LTPS (Low Temperature Poly-Silicon), Either a single crystal semiconductor or a semiconductor partially including a crystal region may be used. It is preferable to use a semiconductor having crystallinity because deterioration of electrical characteristics of the transistor can be suppressed.

  As a semiconductor material used for the transistor, for example, a Group 14 element (such as silicon or germanium), a compound semiconductor, or an oxide semiconductor can be used for the semiconductor layer. Typically, a semiconductor containing silicon, a semiconductor containing gallium arsenide, an oxide semiconductor containing indium, or the like can be used.

  In particular, an oxide semiconductor having a band gap larger than that of silicon is preferably used. It is preferable to use a semiconductor material having a larger band gap and lower carrier density than silicon because current in the off-state of the transistor can be reduced.

  In particular, the semiconductor layer has a plurality of crystal parts, and the crystal part has a c-axis oriented substantially perpendicular to the formation surface of the semiconductor layer or the upper surface of the semiconductor layer, and between adjacent crystal parts (a− It is preferable to use an oxide semiconductor in which it is difficult to confirm the grain boundary in the (b-plane direction). Note that in this specification and the like, such an oxide semiconductor is referred to as a CAAC-OS (C-Axis Aligned Crystalline Oxide Semiconductor or C-Axis Aligned and A-B-Plane Ancillary Oxidon Semiconductor).

  Since such an oxide semiconductor does not have a crystal grain boundary, a crack can be suppressed from occurring in the oxide semiconductor film due to stress when the display panel is bent. Therefore, such an oxide semiconductor can be favorably used for a display panel which is flexible and curved.

  In addition, when an oxide semiconductor having such crystallinity is used for the semiconductor layer, a change in electrical characteristics is suppressed and a highly reliable transistor can be realized.

  In addition, a transistor including an oxide semiconductor whose band gap is larger than that of silicon can hold charge accumulated in a capacitor connected in series with the transistor for a long time because of the low off-state current. By applying such a transistor to a pixel, the driving circuit can be stopped while maintaining the gradation of an image displayed in each display region. As a result, a display device with extremely reduced power consumption can be realized.

  The semiconductor layer is expressed by an In-M-Zn-based oxide containing at least indium, zinc, and M (metal such as aluminum, titanium, gallium, germanium, yttrium, zirconium, lanthanum, cerium, tin, neodymium, or hafnium). It is preferable to include a film to be formed. In addition, in order to reduce variation in electric characteristics of the transistor including the oxide semiconductor, a stabilizer is preferably included together with the transistor.

  Examples of the stabilizer include gallium, tin, hafnium, aluminum, and zirconium contained in the metal described in M above. Other stabilizers include lanthanoids such as lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.

  As an oxide semiconductor included in the semiconductor layer, for example, an In—Ga—Zn-based oxide, an In—Al—Zn-based oxide, an In—Sn—Zn-based oxide, an In—Hf—Zn-based oxide, an In— La-Zn oxide, In-Ce-Zn oxide, In-Pr-Zn oxide, In-Nd-Zn oxide, In-Sm-Zn oxide, In-Eu-Zn oxide In-Gd-Zn-based oxide, In-Tb-Zn-based oxide, In-Dy-Zn-based oxide, In-Ho-Zn-based oxide, In-Er-Zn-based oxide, In-Tm -Zn oxide, In-Yb-Zn oxide, In-Lu-Zn oxide, In-Sn-Ga-Zn oxide, In-Hf-Ga-Zn oxide, In-Al- Ga-Zn-based oxide, In-Sn-Al-Zn-based oxide, In-Sn-Hf-Zn-based Product, can be used In-Hf-Al-Zn-based oxide.

  Note that here, an In—Ga—Zn-based oxide means an oxide containing In, Ga, and Zn as its main components, and there is no limitation on the ratio of In, Ga, and Zn. Moreover, metal elements other than In, Ga, and Zn may be contained.

  The above oxide semiconductor can be used for a semiconductor layer and a conductive layer in the transistor. Of the oxides used for the semiconductor layer and the conductive layer in the transistor, the oxide semiconductor may have the same metal element. By using an oxide semiconductor containing the same metal element for the semiconductor layer and the conductive layer of the transistor, the manufacturing cost of the transistor can be reduced. For example, by using a metal oxide target having the same metal composition, the manufacturing cost of the transistor can be reduced. In addition, an etching gas or an etching solution for processing the semiconductor layer and the conductive layer of the transistor can be used in common. Note that the semiconductor layer and the conductive layer of the transistor may have different compositions even though they have the same metal element. For example, the metal element in the oxide semiconductor film is released during the manufacturing process of the transistor and the capacitor, and may have a metal composition different from that before the manufacturing process.

  The oxide semiconductor included in the semiconductor layer has a band gap of 2 eV or more, preferably 2.5 eV or more, and more preferably 3 eV or more. In this manner, the off-state current of the transistor can be reduced by using an oxide semiconductor with a wide band gap.

  In the case where the oxide semiconductor included in the semiconductor layer is an In-M-Zn oxide, the atomic ratio of the metal elements of the sputtering target used for forming the In-M-Zn oxide is In ≧ M, Zn ≧ It is preferable to satisfy M. As the atomic ratio of the metal elements of such a sputtering target, In: M: Zn = 1: 1: 1, In: M: Zn = 1: 1: 1.2, In: M: Zn = 3: 1: 2, In: M: Zn = 4: 2: 4.1 etc. are preferable. Note that the atomic ratio of the semiconductor layer to be formed includes a variation of plus or minus 40% of the atomic ratio of the metal element contained in the sputtering target as an error.

As the semiconductor layer, an oxide semiconductor film with low carrier density is used. For example, the semiconductor layer has a carrier density of 1 × 10 ¹⁷ / cm ³ or less, preferably 1 × 10 ¹⁵ / cm ³ or less, more preferably 1 × 10 ¹³ / cm ³ or less, more preferably 1 × 10 ¹¹ / cm 3. ³ or less, more preferably less than 1 × 10 ¹⁰ / cm ³ , and an oxide semiconductor having a carrier density of 1 × 10 ⁻⁹ / cm ³ or more can be used. Such an oxide semiconductor is referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor. Such an oxide semiconductor can be said to be an oxide semiconductor that provides stable electric characteristics of a transistor because the impurity concentration is low and the density of defect states is low.

  Note that the present invention is not limited to these, and a transistor having an appropriate composition may be used depending on required electrical characteristics of the transistor (field-effect mobility, threshold voltage, and the like). In order to obtain necessary transistor electrical characteristics, it is preferable that the semiconductor layer have appropriate carrier density, impurity concentration, defect density, atomic ratio of metal element to oxygen, interatomic distance, density, and the like. .

If an oxide semiconductor included in the semiconductor layer contains silicon or carbon which is one of Group 14 elements, oxygen vacancies increase in the semiconductor layer, and the semiconductor layer becomes n-type. Therefore, the concentration of silicon or carbon in the semiconductor layer (concentration obtained by secondary ion mass spectrometry) is 2 × 10 ¹⁸ atoms / cm ³ or less, preferably 2 × 10 ¹⁷ atoms / cm ³ or less.

Further, when alkali metal and alkaline earth metal are combined with an oxide semiconductor, carriers may be generated, which may increase off-state current of the transistor. Therefore, the concentration of alkali metal or alkaline earth metal obtained by secondary ion mass spectrometry in the semiconductor layer is set to 1 × 10 ¹⁸ atoms / cm ³ or less, preferably 2 × 10 ¹⁶ atoms / cm ³ or less.

In addition, when nitrogen is contained in the oxide semiconductor included in the semiconductor layer, electrons serving as carriers are generated, the carrier density is increased, and the oxide semiconductor is likely to be n-type. As a result, a transistor including an oxide semiconductor containing nitrogen is likely to be normally on. Therefore, the nitrogen concentration obtained by secondary ion mass spectrometry in the semiconductor layer is preferably 5 × 10 ¹⁸ atoms / cm ³ or less.

  The semiconductor layer may have a non-single crystal structure, for example. The non-single-crystal structure includes, for example, a CAAC-OS, a polycrystalline structure, a microcrystalline structure, or an amorphous structure. In the non-single-crystal structure, the amorphous structure has the highest density of defect states, and the CAAC-OS has the lowest density of defect states.

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

  Note that the semiconductor layer may be a mixed film including 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. Good. For example, the mixed film may have a single-layer structure or a stacked structure including any two or more of the above-described regions.

<Configuration of CAC-OS>
A structure of a CAC (Cloud-Aligned Composite) -OS that can be used for the transistor disclosed in one embodiment of the present invention is described below.

  The CAC-OS is one structure of a material in which an element included in an oxide semiconductor is unevenly distributed with a size of 0.5 nm to 10 nm, preferably 1 nm to 2 nm, or the vicinity thereof. Note that in the following, in an oxide semiconductor, one or more metal elements are unevenly distributed, and a region including the metal element has a size of 0.5 nm to 10 nm, preferably 1 nm to 2 nm, or the vicinity thereof. The state mixed with is also referred to as mosaic or patch.

  Note that the oxide semiconductor preferably contains at least indium. In particular, it is preferable to contain indium and zinc. In addition, aluminum, gallium, yttrium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, etc. One kind selected from the above or a plurality of kinds may be included.

For example, a CAC-OS in In-Ga-Zn oxide (In-Ga-Zn oxide among CAC-OSs may be referred to as CAC-IGZO in particular) is an indium oxide (hereinafter referred to as InO). _X1 (X1 is greater real than 0) and.), or indium zinc oxide _{(hereinafter, in X2 Zn Y2 O Z2 (} X2, Y2, and Z2 is larger real than 0) and a.), gallium An oxide (hereinafter referred to as GaO _X3 (X3 is a real number greater than 0)) or a gallium zinc oxide (hereinafter referred to as Ga _X4 Zn _Y4 O _Z4 (where X4, Y4, and Z4 are greater than 0)) to.) and the like, the material becomes mosaic by separate into, mosaic _{InO X1,} or _in X2 _Zn Y2 _{O Z2} is configured uniformly distributed in the film (hereinafter, cloud Also referred to.) A.

That, CAC-OS includes a region _{GaO X3} is the main _component, In _{X2 Zn} Y2 _{O Z2,} or _{InO X1} there is a region which is a main component, a composite oxide semiconductor having a structure that is mixed. Note that in this specification, for example, the first region indicates that the atomic 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. It is assumed that the concentration of In is higher than that in the second region.

Note that IGZO is a common name and sometimes refers to one compound of In, Ga, Zn, and O. As a typical example, 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 an arbitrary number) A crystalline compound may be mentioned.

  The crystalline compound has a single crystal structure, a polycrystalline structure, or a CAAC structure. The CAAC structure is a crystal structure in which a plurality of IGZO nanocrystals have c-axis orientation and are connected without being oriented in the ab plane.

  On the other hand, CAC-OS relates to a material structure of an oxide semiconductor. CAC-OS refers to a region that is observed in the form of nanoparticles mainly composed of Ga in a material structure including In, Ga, Zn, and O, and nanoparticles that are partially composed mainly of In. The region observed in a shape is a configuration in which the regions are randomly dispersed in a mosaic shape. Therefore, in the CAC-OS, the crystal structure is a secondary element.

  Note that the CAC-OS does not include a stacked structure of two or more kinds of films having different compositions. For example, a structure composed of two layers of a film mainly containing In and a film mainly containing Ga is not included.

Incidentally, a region _{GaO X3} is the main _component, In _{X2 Zn} Y2 _{O Z2,} or the region _{InO X1} is the main component, it may be difficult to observe a clear boundary.

  Instead of gallium, selected from aluminum, yttrium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, etc. In the case where one or a plurality of types are included, the CAC-OS includes a region that is observed in a part of a nanoparticle mainly including the metal element as a main component and a nanoparticle mainly including In as a main component. The region observed in the form of particles refers to a configuration in which each region is randomly dispersed in a mosaic shape.

  The CAC-OS can be formed by a sputtering method under a condition that the substrate is not intentionally heated, for example. In the case where the CAC-OS is formed by a sputtering method, any one or more selected from an inert gas (typically argon), an oxygen gas, and a nitrogen gas may be used as a deposition gas. Good. Further, the flow rate ratio of the oxygen gas to the total flow rate of the deposition gas during the deposition is preferably as low as possible. For example, the flow rate ratio of the oxygen gas is 0% or more and less than 30%, preferably 0% or more and 10% or less.

  The CAC-OS is characterized in that no clear peak is observed when measured using a θ / 2θ scan by the Out-of-plane method, which is one of the X-ray diffraction (XRD) measurement methods. Have That is, it can be seen from X-ray diffraction that no orientation in the ab plane direction and c-axis direction of the measurement region is observed.

  In addition, in the CAC-OS, an electron beam diffraction pattern obtained by irradiating an electron beam with a probe diameter of 1 nm (also referred to as a nanobeam electron beam) has a ring-like region having a high luminance and a plurality of bright regions in the ring region. A point is observed. Therefore, it can be seen from the electron beam diffraction pattern that the crystal structure of the CAC-OS has an nc (nano-crystal) structure having no orientation in the planar direction and the cross-sectional direction.

Further, for example, in a CAC-OS in an In—Ga—Zn oxide, a region in which GaO _X3 is a main component is obtained by EDX mapping obtained by using energy dispersive X-ray spectroscopy (EDX). It can be confirmed that a region in which In _X2 Zn _Y2 O _Z2 or InO _X1 is a main component is unevenly distributed and mixed.

The CAC-OS has a structure different from that of the IGZO compound in which the metal element is uniformly distributed, and has a property different from that of the IGZO compound. That is, in the CAC-OS, a region in which GaO _X3 or the like is a main component and a region in which In _X2 Zn _Y2 O _Z2 or InO _X1 is a main component are phase-separated from each other, and a region in which each element is a main component. Has a mosaic structure.

Here, the region containing In _X2 Zn _Y2 O _Z2 or InO _X1 as a main component is a region having higher conductivity than a region containing GaO _X3 or the like as a main component. _That, In _{X2 Zn} Y2 _{O Z2,} or _{InO X1} is a region which is a main component, by carriers flow, expressed the conductivity of the oxide semiconductor. Therefore, a region containing In _X2 Zn _Y2 O _Z2 or InO _X1 as a main component is distributed in a cloud shape in an oxide semiconductor, so that a transistor using the oxide semiconductor achieves high field-effect mobility. it can.

On the other hand, areas such as _{GaO X3} is the main _component, In _{X2 Zn} Y2 _{O Z2,} or _{InO X1} is compared to region which is a main component, has a high area insulation. In other words, a region containing GaO _X3 or the like as a main component is distributed in an oxide semiconductor, so that a transistor using the oxide semiconductor can suppress a leakage current and realize a favorable switching operation.

Therefore, when CAC-OS is used for a semiconductor element such as a transistor, conductivity caused by In _X2 Zn _Y2 O _Z2 or InO _X1 and insulation caused by GaO _X3 or the like act complementarily. Thus, both a high on-current and a low off-current can be realized.

  In addition, a semiconductor element using a CAC-OS has high reliability. Therefore, the CAC-OS is optimally used for various semiconductor devices including a display.

  Alternatively, silicon may be used for the semiconductor layer in which the channel region of the transistor is formed. Although amorphous silicon may be used as silicon, it is particularly preferable to use silicon having crystallinity. For example, microcrystalline silicon, polycrystalline silicon, single crystal silicon, or the like is preferably used. In particular, polycrystalline silicon can be formed at a lower temperature than single crystal silicon, and has higher field effect mobility and higher reliability than amorphous silicon. By applying such a polycrystalline semiconductor to a pixel, the aperture ratio of the pixel can be improved. In addition, even in the case of an extremely high-definition display portion, the gate driver circuit and the source driver circuit can be formed over the same substrate as the pixel, and the number of components included in the electronic device can be reduced. .

  The bottom-gate transistor described in this embodiment is preferable because the number of manufacturing steps can be reduced. At this time, since amorphous silicon is used for the semiconductor layer, it can be formed at a temperature lower than that of polycrystalline silicon. Therefore, the wiring below the semiconductor layer should be made of a material having low heat resistance as the electrode material and the substrate material. It is possible to expand the range of selection of materials. For example, a glass substrate having an extremely large area can be used. On the other hand, a top-gate transistor is preferable because an impurity region can be easily formed in a self-aligned manner and variation in electrical characteristics can be reduced. In particular, the semiconductor layer is suitable when polycrystalline silicon, single crystal silicon, or the like is used.

[Conductive layer]
In addition to the gate, source, and drain of a transistor, materials that can be used for conductive layers such as various wirings and electrodes included in the display device 10 of one embodiment of the present invention include aluminum, titanium, chromium, nickel, copper, and yttrium. , Zirconium, molybdenum, silver, tantalum, or tungsten, or an alloy containing the same as a main component. A film containing any of these materials can be used as a single layer or a stacked layer. For example, a single layer structure of an aluminum film containing silicon, a two layer structure in which an aluminum film is stacked on a titanium film, a two layer structure in which an aluminum film is stacked on a tungsten film, and a copper film on a copper-magnesium-aluminum alloy film Two-layer structure to stack, two-layer structure to stack copper film on titanium film, two-layer structure to stack copper film on tungsten film, titanium film or titanium nitride film, and aluminum film or copper film on top of it A three-layer structure for forming a titanium film or a titanium nitride film thereon, a molybdenum film or a molybdenum nitride film, and an aluminum film or a copper film stacked thereon, and a molybdenum film or There is a three-layer structure for forming a molybdenum nitride film. Note that an oxide such as indium oxide, tin oxide, or zinc oxide may be used. Further, it is preferable to use copper containing manganese because the controllability of the shape by etching is increased.

  As the light-transmitting conductive material, conductive oxide such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, or zinc oxide to which gallium is added, or graphene can be used. Alternatively, a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, or an alloy material containing the metal material can be used. Alternatively, a nitride (eg, titanium nitride) of the metal material may be used. Note that in the case where a metal material or an alloy material (or a nitride thereof) is used, it may be thin enough to have a light-transmitting property. In addition, a stacked film of the above materials can be used as a conductive layer. For example, it is preferable to use a laminated film of an alloy of silver and magnesium and indium tin oxide because the conductivity can be increased. These can also be used for conductive layers such as various wirings and electrodes constituting the display device and conductive layers (conductive layers functioning as pixel electrodes and common electrodes) included in the display element.

[Insulation layer]
Insulating materials that can be used for each insulating layer include, for example, resins such as acrylic and epoxy, resins having a siloxane bond such as silicone, silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide An inorganic insulating material such as can also be used.

  The light-emitting element is preferably provided between a pair of insulating films with low water permeability. Thereby, impurities such as water can be prevented from entering the light emitting element, and a decrease in reliability of the apparatus can be suppressed.

  Examples of the low water-permeable insulating film include a film containing nitrogen and silicon such as a silicon nitride film and a silicon nitride oxide film, and a film containing nitrogen and aluminum such as an aluminum nitride film. Alternatively, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, or the like may be used.

For example, the water vapor transmission rate of an 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, it is 1 × 10 ⁻⁷ [g / (m ² · day)] or less, and further preferably 1 × 10 ⁻⁸ [g / (m ² · day)] or less.

[Liquid crystal element]
As the liquid crystal element, for example, a liquid crystal element to which a vertical alignment (VA) mode is applied 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.

  As the liquid crystal element, liquid crystal elements to which various modes are applied can be used. For example, in addition to the VA mode, a TN (Twisted Nematic) mode, an IPS (In-Plane-Switching) mode, an IPS-VA mode, an FFS (Fringe Field Switching) mode, an ASM (Axial Symmetrical Aligned MicroB) mode A liquid crystal element to which an (Optically Compensated Birefringence) mode, an FLC (Ferroelectric Liquid Crystal) mode, an AFLC (Anti-Ferroelectric Liquid Crystal) mode, or the like can be used.

  Note that the liquid crystal element is an element that controls transmission or non-transmission of light by an optical modulation action of liquid crystal. Note that the optical modulation action of the liquid crystal is controlled by an electric field applied to the liquid crystal (including a horizontal electric field, a vertical electric field, or an oblique electric field). As the liquid crystal used in the liquid crystal element, a thermotropic liquid crystal, a low molecular liquid crystal, a polymer liquid crystal, a polymer dispersed liquid crystal (PDLC), a ferroelectric liquid crystal, an antiferroelectric liquid crystal, or the like is used. Can do. These liquid crystal materials exhibit a cholesteric phase, a smectic phase, a cubic phase, a chiral nematic phase, an isotropic phase, and the like depending on conditions.

  Further, as the liquid crystal material, either a positive type liquid crystal or a negative type liquid crystal may be used, and an optimal liquid crystal material may be used according to an applied mode or design.

  An alignment film can be provided to control the alignment of the liquid crystal. Note that in the case of employing a horizontal electric field mode, liquid crystal exhibiting a blue phase for which an alignment film is unnecessary may be used. The blue phase is one of the liquid crystal phases, and is a phase that appears immediately before the transition from the cholesteric phase to the isotropic 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 mixed with several percent by weight or more of a chiral agent is used for the liquid crystal layer in order to improve the temperature range. A liquid crystal composition containing a liquid crystal exhibiting a blue phase and a chiral agent has a short response speed and optical isotropy. In addition, a liquid crystal composition including a liquid crystal exhibiting a blue phase and a chiral agent does not require alignment treatment and has a small viewing angle dependency. In addition, since it is not necessary to provide an alignment film, a rubbing process is unnecessary, so that electrostatic breakdown caused by the rubbing process can be prevented, and defects or breakage of the liquid crystal display device during the manufacturing process can be reduced. it can.

  As the liquid crystal element, a transmissive liquid crystal element, a reflective liquid crystal element, a transflective 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.

In the case of using a transmissive or transflective liquid crystal element, two polarizing plates are provided so as to sandwich a pair of substrates. A backlight is provided outside the polarizing plate. The backlight may be a direct type backlight or an edge light type backlight. It is preferable to use a direct-type backlight including an LED (Light Emitting Diode) because local dimming is facilitated and contrast can be increased. An edge light type backlight is preferably used because the thickness of the module including the backlight can be reduced.
Therefore, it is preferable.

  In the case of using a reflective liquid crystal element, a polarizing plate is provided on the display surface side. Separately from this, it is preferable to arrange a light diffusing plate on the display surface side because the visibility can be improved.

  In the case of using a reflective or transflective liquid crystal element, a front light may be provided outside the polarizing plate. As the front light, an edge light type front light is preferably used. It is preferable to use a front light including an LED (Light Emitting Diode) because power consumption can be reduced.

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

  Light emitting elements include a top emission type, a bottom emission type, and a dual emission type. A conductive film that transmits visible light is used for the electrode from which light is extracted. In addition, a conductive film that reflects visible light is preferably used for the electrode from which light is not extracted.

  The EL layer has at least a light emitting layer. The EL layer is a layer other than the light-emitting layer, such as a substance having a high hole injection property, a substance having a high hole transport property, a hole blocking material, a substance having a high electron transport property, a substance having a high electron injection property, or a bipolar property. A layer including a substance (a substance having a high electron transporting property and a high hole transporting property) and the like may be further included.

  In the EL layer, either a low molecular compound or a high molecular compound can be used, and an inorganic compound may be included. The layers constituting the EL layer can be formed by a method such as a vapor deposition method (including a vacuum vapor deposition method), a transfer method, a printing method, an ink jet method, or a coating method.

  When a voltage higher than the threshold 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 from the cathode side. The injected electrons and holes are recombined in the EL layer, and the light-emitting substance contained in the EL layer emits light.

  In the case where a white light-emitting element is used as the light-emitting element, the EL layer preferably includes two or more light-emitting substances. For example, white light emission can be obtained by selecting a light emitting material so that light emission of each of two or more light emitting materials has a complementary color relationship. For example, a luminescent material that emits light such as R (red), G (green), B (blue), Y (yellow), and O (orange), or spectral components of two or more colors of R, G, and B It is preferable that 2 or more are included among the luminescent substances which show light emission containing. In addition, it is preferable to apply a light-emitting element whose emission spectrum from the light-emitting element has two or more peaks within a wavelength range of visible light (for example, 350 nm to 750 nm). The emission spectrum of the material having a peak in the yellow wavelength region is preferably a material having spectral components in the green and red wavelength regions.

  The EL layer preferably has a structure in which a light-emitting layer including a light-emitting material that emits one color and a light-emitting layer including a light-emitting material that emits another color are stacked. For example, the plurality of light emitting layers in the EL layer may be stacked in contact with each other, or may be stacked through a region not including any light emitting material. For example, a configuration in which a region containing the same material (for example, a host material or an assist material) as the fluorescent light emitting layer or the phosphorescent light emitting layer and not including any light emitting material is provided between the fluorescent light emitting layer and the phosphorescent light emitting layer. It is good. This facilitates the production of the light emitting element and reduces the driving voltage.

  The light-emitting element may be a single element having one EL layer or a tandem element in which a plurality of EL layers are stacked with a charge generation layer interposed therebetween.

  The conductive film that transmits visible light can be formed using, for example, indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide to which gallium is added, or the like. In addition, a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, an alloy containing these metal materials, or a nitride of these metal materials (for example, Titanium nitride) can also be used by forming it thin enough to have translucency. In addition, a stacked film of the above materials can be used as a conductive layer. For example, it is preferable to use a stacked film of an alloy of silver and magnesium and indium tin oxide because the conductivity can be increased. Further, graphene or the like may be used.

  As the conductive film that reflects visible light, for example, a metal material such as aluminum, gold, platinum, silver, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium, or an alloy including these metal materials is used. Can do. In addition, lanthanum, neodymium, germanium, or the like may be added to the metal material or alloy. Alternatively, titanium, nickel, or neodymium and an alloy containing aluminum (aluminum alloy) may be used. Alternatively, an alloy containing copper, palladium, magnesium, and silver may be used. An alloy containing silver and copper is preferable because of its high heat resistance. Furthermore, oxidation can be suppressed by stacking a metal film or a metal oxide film in contact with the aluminum film or the aluminum alloy film. Examples of materials for such metal films and metal oxide films include titanium and titanium oxide. Alternatively, the conductive film that transmits visible light and a film made of a metal material may be stacked. 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.

  The electrodes may be formed using a vapor deposition method or a sputtering method, respectively. In addition, it can be formed using a discharge method such as an inkjet method, a printing method such as a screen printing method, or a plating method.

  Note that the above-described light-emitting layer, a substance having a high hole-injecting property, a substance having a high hole-transporting property, a substance having a high electron-transporting property, a substance having a high electron-injecting property, a bipolar substance, and the like You may have inorganic compounds, such as a dot, and high molecular compounds (an oligomer, a dendrimer, a polymer, etc.). For example, a quantum dot can be used for a light emitting layer to function 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, or the like can be used. Alternatively, a material including an element group of Group 12 and Group 16, Group 13 and Group 15, or Group 14 and Group 16 may be used. Alternatively, a quantum dot material containing an element such as cadmium, selenium, zinc, sulfur, phosphorus, indium, tellurium, lead, gallium, arsenic, or aluminum may be used.

[Adhesive layer]
As the adhesive layer, various curable adhesives such as an ultraviolet curable photocurable adhesive, a reactive curable adhesive, a thermosetting adhesive, and an anaerobic adhesive can be used. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenol resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, EVA (ethylene vinyl acetate) resins, and the like. . In particular, a material with low moisture permeability such as an epoxy resin is preferable. Alternatively, a two-component mixed resin may be used. Further, an adhesive sheet or the like may be used.

  Further, the resin may contain a desiccant. For example, a substance that adsorbs moisture by chemical adsorption, such as an alkaline earth metal oxide (such as calcium oxide or barium oxide), can be used. Alternatively, a substance that adsorbs moisture by physical adsorption, such as zeolite or silica gel, may be used. The inclusion of a desiccant is preferable because impurities such as moisture can be prevented from entering the element and the reliability of the display panel is improved.

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

(Connection layer)
As the connection layer, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), or the like can be used.

(Colored layer)
Examples of materials that can be used for the colored layer include metal materials, resin materials, resin materials containing pigments or dyes, and the like.

[Light shielding layer]
Examples of the material that can be used for the light-shielding layer include carbon black, titanium black, metal, metal oxide, and composite oxide containing a solid solution of a plurality of metal oxides. The light shielding layer may be a film containing a resin material or a thin film of an inorganic material such as a metal. Alternatively, a stacked film of a film containing a material for the colored layer can be used for the light shielding layer. For example, a stacked structure of a film including a material used for a colored layer that transmits light of a certain color and a film including a material used for a colored layer that transmits light of another color can be used. It is preferable to use a common material for the coloring layer and the light shielding layer because the device can be shared and the process can be simplified.

  The above is the description of each component of the display panel 100.

<Example of production method>
Here, an example of a method for manufacturing the display panel 100 using a flexible substrate will be described.

  Here, a layer including a display element, a circuit, a wiring, an electrode, an optical member such as a coloring layer or a light shielding layer, and an insulating layer is collectively referred to as an element layer. For example, the element layer includes a display element, and may include an element such as a wiring that is electrically connected to the display element, a transistor used for a pixel, or a circuit in addition to the display element.

  Here, a member that supports the element layer and has flexibility when the display element is completed (the manufacturing process is completed) is referred to as a substrate. For example, the substrate includes a very thin film having a thickness of 10 nm to 300 μm.

  As a method for forming an element layer over a flexible substrate having an insulating surface, there are typically two methods described below. One is a method of forming an element layer directly on a substrate. The other is a method in which an element layer is formed on a support base different from the substrate, then the element layer and the support base are peeled off, and the element layer is transferred to the substrate. Although not described in detail here, in addition to the two methods described above, a method of providing flexibility by forming an element layer on a non-flexible substrate and thinning the substrate by polishing or the like. There is also.

  In the case where the material constituting the substrate has heat resistance against the heat applied to the element layer forming step, it is preferable to form the element layer directly on the substrate because the process is simplified. At this time, it is preferable to form the element layer in a state in which the substrate is fixed to the supporting base material, because it is easy to carry the device inside and between devices.

  In the case of using a method in which the element layer is formed on the supporting base material and then transferred to the substrate, a peeling layer and an insulating layer are first stacked on the supporting base material, and the element layer is formed on the insulating layer. Then, it peels between a support base material and an element layer, and transfers an element layer to a board | substrate. At this time, a material that causes peeling in the interface between the supporting substrate and the peeling layer, the interface between the peeling layer and the insulating layer, or the peeling layer may be selected. In this method, by using a material having high heat resistance for the support substrate and the release layer, the upper limit of the temperature required for forming the element layer can be increased, and an element layer having a more reliable element is formed. This is preferable because it is possible.

  For example, a layer containing a refractory metal material such as tungsten and a layer containing an oxide of the metal material are stacked as the separation layer, and silicon oxide, silicon nitride, or silicon oxynitride is used as the insulating layer over the separation layer. It is preferable to use a layer in which a plurality of silicon nitride oxides or the like are stacked. Note that in this specification, oxynitride refers to a material having a higher oxygen content than nitrogen as its composition, and nitride oxide refers to a material having a higher nitrogen content than oxygen as its composition. Point to.

  Examples of methods for peeling the element layer and the supporting substrate include applying a mechanical force, etching the peeling layer, or infiltrating a liquid into the peeling interface. Or you may peel by heating or cooling using the difference of the thermal expansion of two layers which form a peeling interface.

  In the case where peeling is possible at the interface between the support base and the insulating layer, the peeling layer may not be provided.

  For example, glass can be used as the supporting substrate, and an organic resin such as polyimide can be used as the insulating layer. At this time, a part of the organic resin is locally heated using a laser beam or the like, or a part of the organic resin is physically cut or penetrated by a sharp member, etc. Peeling may be performed at the interface between the glass and the organic resin.

  Alternatively, peeling may be performed at the interface between the heat generation layer and the insulating layer by providing a heat generation layer between the support base and the insulating layer made of an organic resin and heating the heat generation layer. As the heat generating layer, various materials such as a material that generates heat when an electric current flows, a material that generates heat by absorbing light, and a material that generates heat by applying a magnetic field can be used. For example, the heat generating layer can be selected from semiconductors, metals, and insulators.

  Note that in the above-described method, the insulating layer formed of an organic resin can be used as a substrate after peeling.

  The above is the description of the method for manufacturing the flexible display panel 100.

  This embodiment can be implemented in appropriate combination with at least part of the other embodiments described in this specification.

(Embodiment 3)
In this embodiment, an electronic device and a lighting device according to one embodiment of the present invention will be described with reference to drawings.

  An electronic device or a lighting device can be manufactured using the display device 10 of one embodiment of the present invention. A highly reliable electronic device or lighting device can be manufactured using the display device 10 of one embodiment of the present invention. In addition, an electronic device or a lighting device with reduced power consumption can be manufactured using the display device 10 of one embodiment of the present invention.

  By applying the display device 10 of one embodiment of the present invention, for example, in a place where the illuminance of outside light is sufficiently high, such as a sunny field, a mode (first mode) for displaying an image using reflected light is provided. By using the electronic device, a clear image can be displayed. In addition, for example, in a place where the illuminance of outside light is extremely low, such as at night or in a dark room, a vivid image or a smooth video is displayed by using a mode (second mode) that displays an image using light emission. An electronic device can be provided. In addition, for example, when the illuminance of outside light is relatively low, such as under room lighting or in the morning or evening hours, or when the chromaticity of the outside light is not white, both reflected light and light emission are used. By using the mode for displaying an image (third mode), it is possible to provide an electronic device that displays an image that makes you feel as if you are watching a painting. The display device 10 of one embodiment of the present invention can automatically switch to the display in the first mode, for example, when the display in the second mode continues for a long time. Therefore, it is possible to provide an electronic device that suppresses deterioration of a light-emitting element (such as an organic EL) that performs display in the second mode and avoids or reduces the problem of image sticking.

  Examples of the electronic device according to one embodiment of the present invention include a television device, a desktop or notebook personal computer, a monitor for a computer, a digital camera, a digital video camera, a digital photo frame, a mobile phone, and a portable game Large game machines such as a game machine, a portable information terminal, a sound reproduction device, and a pachinko machine.

  The electronic device or the lighting device according to one embodiment of the present invention can be incorporated along an inner wall or an outer wall of a house or a building, or a curved surface of an interior or exterior of an automobile.

  The electronic device according to one embodiment of the present invention may include a secondary battery, and it is preferable that the secondary battery can be charged using non-contact power transmission.

  Secondary batteries include, for example, lithium ion secondary batteries such as lithium polymer batteries (lithium ion polymer batteries) using gel electrolyte, nickel metal hydride batteries, nickel-cadmium batteries, organic radical batteries, lead storage batteries, air secondary batteries, nickel A zinc battery, a silver zinc battery, etc. are mentioned.

  The electronic device according to one embodiment of the present invention may include an antenna. By receiving a signal with an antenna, video, information, and the like can be displayed on the display unit. In the case where the electronic device has an antenna and a secondary battery, the antenna may be used for non-contact power transmission.

  An electronic device according to one embodiment of the present invention includes a sensor (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, and current. , Voltage, power, radiation, flow rate, humidity, gradient, vibration, odor (or odor), or infrared measurement function).

  The electronic device according to one embodiment of the present invention can have a variety of functions. For example, a function for displaying various information (still images, moving images, text images, etc.) on the display unit, a touch panel function, a function for displaying a calendar, date or time, a function for executing various software (programs), and wireless communication It can have a function, a function of reading a program or data recorded in a recording medium, and the like.

  Furthermore, in an electronic apparatus having a plurality of display units, one display unit mainly displays image information, and another one display unit mainly displays character information, or the plurality of display units consider parallax. By displaying an image, it is possible to have a function of displaying a three-dimensional image. Furthermore, in an electronic device having an image receiving unit, a function for photographing a still image or a moving image, a function for automatically or manually correcting the photographed image, and a function for saving the photographed image in a recording medium (externally or incorporated in the electronic device) A function of displaying the photographed image on the display portion can be provided. Note that the functions of the electronic device according to one embodiment of the present invention are not limited thereto, and the electronic device can have various functions.

  FIGS. 13A to 13E illustrate an example of an electronic device including the curved display portion 7000. FIG. The display portion 7000 is provided with a curved display surface, and can perform display along the curved display surface. Note that the display portion 7000 may have flexibility.

  The display portion 7000 is manufactured using the display device 10 or the like of one embodiment of the present invention. According to one embodiment of the present invention, an electronic device with reduced power consumption, a curved display portion, and high reliability can be provided.

  An example of a cellular phone is shown in FIGS. A cellular phone 7100 illustrated in FIG. 13A and a cellular phone 7110 illustrated in FIG. 13B each include a housing 7101, a display portion 7000, operation buttons 7103, an external connection port 7104, a speaker 7105, a microphone 7106, and the like. . A cellular phone 7110 illustrated in FIG. 13B further includes a camera 7107.

  Each mobile phone includes a touch sensor in the display unit 7000. All operations such as making a call or inputting characters can be performed by touching the display portion 7000 with a finger or a stylus.

  Further, by operating the operation button 7103, the power ON / OFF operation and the type of image displayed on the display portion 7000 can be switched. For example, the mail creation screen can be switched to the main menu screen.

  Further, by providing a detection device such as a gyro sensor or an acceleration sensor inside the mobile phone, the orientation of the mobile phone (vertical or horizontal) is determined, and the screen display orientation of the display unit 7000 is automatically switched. Can be. The screen display direction can also be switched by touching the display portion 7000, operating the operation buttons 7103, or inputting voice using the microphone 7106.

  FIG. 13C and FIG. 13D each show an example of a portable information terminal. A portable information terminal 7200 illustrated in FIG. 13C and a portable information terminal 7210 illustrated in FIG. 13D each include a housing 7201 and a display portion 7000. Furthermore, an operation button, an external connection port, a speaker, a microphone, an antenna, a camera, a battery, or the like may be included. The display unit 7000 includes a touch sensor. The portable information terminal can be operated by touching the display portion 7000 with a finger or a stylus.

  The portable information terminal exemplified in this embodiment has one or a plurality of functions selected from, for example, a telephone, a notebook, an information browsing device, or the like. Specifically, each can be used as a smartphone. The portable information terminal exemplified in this embodiment can execute various applications such as mobile phone, e-mail, text browsing and creation, music playback, Internet communication, and computer games.

  The portable information terminal 7200 and the portable information terminal 7210 can display characters, image information, and the like on a plurality of surfaces. For example, as shown in FIGS. 13C and 13D, three operation buttons 7202 can be displayed on one surface, and information 7203 indicated by a rectangle can be displayed on the other surface. FIG. 13C illustrates an example in which information is displayed on the upper side of the portable information terminal, and FIG. 13D illustrates an example in which information is displayed on the side of the portable information terminal. Further, information may be displayed on three or more surfaces of the portable information terminal.

  Examples of information include SNS (social networking service) notifications, indications indicating incoming e-mails and telephone calls, titles or sender names of e-mails, date / time, time, battery level, antenna There is the strength of reception. Alternatively, an operation button, an icon, or the like may be displayed instead of the information at a position where the information is displayed.

  For example, the user of the portable information terminal 7200 can check the display (here, information 7203) in a state where the portable information terminal 7200 is stored in the chest pocket of clothes.

  Specifically, the telephone number or name of the caller of the incoming call is displayed at a position where it can be observed from above portable information terminal 7200. The user can check the display and determine whether to receive a call without taking out the portable information terminal 7200 from the pocket.

  FIG. 13E illustrates an example of a television device. In the television device 7300, a display portion 7000 is incorporated in a housing 7301. Here, a structure in which the housing 7301 is supported by a stand 7303 is shown.

  The television device 7300 illustrated in FIG. 13E can be operated with an operation switch included in the housing 7301 or a separate remote controller 7311. Alternatively, the display unit 7000 may be provided with a touch sensor, and may be operated by touching the display unit 7000 with a finger or the like. The remote controller 7311 may include a display unit that displays information output from the remote controller 7311. Channels and volume can be operated with operation keys or a touch panel included in the remote controller 7311, and an image displayed on the display portion 7000 can be operated.

  Note that the television device 7300 is provided with a receiver, a modem, and the like. The receiver can receive a general television broadcast. In addition, by connecting to a wired or wireless communication network via a modem, information communication is performed in one direction (from the sender to the receiver) or in two directions (between the sender and the receiver or between the receivers). It is also possible.

  FIG. 13F illustrates an example of a lighting device having a curved light-emitting portion.

  A light-emitting portion included in the lighting device illustrated in FIG. 13F is manufactured using the display device 10 or the like of one embodiment of the present invention. According to one embodiment of the present invention, a highly reliable lighting device with low power consumption, a curved light-emitting portion, and high reliability can be provided.

  A light emitting portion 7411 included in the lighting device 7400 illustrated in FIG. 13F has a structure in which two light emitting portions curved in a convex shape are arranged symmetrically. Therefore, all directions can be illuminated with the lighting device 7400 as the center.

  In addition, the light-emitting portion included in the lighting device 7400 may have flexibility. The light emitting portion 7411 may be fixed by a member such as a plastic member or a movable frame, and the light emitting surface of the light emitting portion 7411 may be freely bent according to the application.

  The lighting device 7400 includes a base portion 7401 including an operation switch 7403 and a light emitting portion 7411 supported by the base portion 7401.

  Note that although the lighting device in which the light emitting unit is supported by the base is illustrated here, the housing including the light emitting unit may be fixed to the ceiling or used so as to be suspended from the ceiling. Since the light emitting surface can be curved and used, the light emitting surface can be curved concavely to illuminate a specific area, or the light emitting surface can be curved convexly to illuminate the entire room.

  FIGS. 14A to 14I illustrate an example of a portable information terminal including a display portion 7001 which is flexible and can be bent.

  The display portion 7001 is manufactured using the display device 10 or the like of one embodiment of the present invention. For example, a display device that can be bent with a curvature radius of 0.01 mm to 150 mm can be applied. The display portion 7001 may include a touch sensor, and the portable information terminal can be operated by touching the display portion 7001 with a finger or the like. According to one embodiment of the present invention, a highly reliable electronic device including a flexible display portion can be provided.

  14A and 14B are perspective views illustrating an example of a portable information terminal. A portable information terminal 7500 includes a housing 7501, a display portion 7001, a drawer member 7502, operation buttons 7503, and the like.

  A portable information terminal 7500 includes a flexible display portion 7001 wound in a roll shape in a housing 7501. The display portion 7001 can be pulled out using the pull-out member 7502.

  In addition, the portable information terminal 7500 can receive a video signal by a built-in control unit, and can display the received video on the display unit 7001. In addition, the portable information terminal 7500 has a built-in battery. Further, a terminal portion for connecting a connector to the housing 7501 may be provided, and a video signal and power may be directly supplied from the outside by wire.

  Further, operation buttons 7503 can be used to perform power ON / OFF operations, switching of displayed images, and the like. 14A and 14B illustrate an example in which the operation button 7503 is arranged on the side surface of the portable information terminal 7500, but the present invention is not limited to this, and the same surface (the same as the display surface of the portable information terminal 7500). It may be arranged on the front surface) or on the back surface.

  FIG. 14B illustrates the portable information terminal 7500 with the display portion 7001 pulled out. In this state, an image can be displayed on the display portion 7001. A configuration in which the portable information terminal 7500 performs different display in the state of FIG. 14A in which part of the display portion 7001 is wound in a roll shape and the state of FIG. 14B in which the display portion 7001 is pulled out is performed. It is good. For example, in the state of FIG. 14A, power consumption of the portable information terminal 7500 can be reduced by hiding a portion of the display portion 7001 wound in a roll shape.

  Note that a reinforcing frame may be provided on a side portion of the display portion 7001 in order to fix the display surface of the display portion 7001 so that the display surface is flat when the display portion 7001 is pulled out.

  In addition to this configuration, a speaker may be provided in the housing 7501 so that sound is output by an audio signal received together with the video signal.

  FIGS. 14C to 14E illustrate an example of a foldable portable information terminal. In FIG. 14C, the mobile information terminal is in the expanded state, in FIG. 14D, in the middle of changing from one of the expanded state or the folded state to the other, in FIG. 14E, the portable information terminal in the folded state 7600 is shown. The portable information terminal 7600 is excellent in portability in the folded state, and in the expanded state, the portable information terminal 7600 is excellent in listability due to a seamless wide display area.

  The display portion 7001 is supported by three housings 7601 connected by hinges 7602. By bending between the two housings 7601 through the hinge 7602, the portable information terminal 7600 can be reversibly deformed from a developed state to a folded state.

  FIGS. 14F and 14G illustrate an example of a foldable portable information terminal. FIG. 14F illustrates the portable information terminal 7650 in a state where the display portion 7001 is folded so as to be on the inside, and FIG. 14G illustrates a portable information terminal 7650 in a state where the display portion 7001 is folded on the outside. The portable information terminal 7650 includes a display portion 7001 and a non-display portion 7651. When the portable information terminal 7650 is not used, the display portion 7001 can be folded so that the display portion 7001 is on the inner side, whereby the display portion 7001 can be prevented from being stained and damaged.

  FIG. 14H illustrates an example of a portable information terminal having flexibility. A portable information terminal 7700 includes a housing 7701 and a display portion 7001. Further, a button 7703a and a button 7703b that are input means, a speaker 7704a and a speaker 7704b that are sound output means, an external connection port 7705, a microphone 7706, and the like may be provided. In addition, the portable information terminal 7700 can be equipped with a flexible battery 7709. The battery 7709 may be disposed so as to overlap with the display portion 7001, for example.

  The housing 7701, the display portion 7001, and the battery 7709 have flexibility. Therefore, it is easy to curve the portable information terminal 7700 into a desired shape and to twist the portable information terminal 7700. For example, the portable information terminal 7700 can be used by being folded so that the display portion 7001 is inside or outside. Alternatively, the portable information terminal 7700 can be used in a rolled state. In this manner, since the housing 7701 and the display portion 7001 can be freely deformed, the portable information terminal 7700 is hardly damaged even when it is dropped or an unintended external force is applied. There are advantages.

  Further, since the portable information terminal 7700 is lightweight, it can be used by holding the top of the housing 7701 with a clip or the like and hanging it, or by fixing the housing 7701 to a wall surface with a magnet or the like. Can be used conveniently.

  FIG. 14I illustrates an example of a wristwatch-type portable information terminal. A portable information terminal 7800 includes a band 7801, a display portion 7001, input / output terminals 7802, operation buttons 7803, and the like. The band 7801 has a function as a housing. Further, the portable information terminal 7800 can be equipped with a flexible battery 7805. The battery 7805 may be disposed so as to overlap with the display portion 7001 or the band 7801, for example.

  The band 7801, the display portion 7001, and the battery 7805 are flexible. Therefore, it is easy to curve the portable information terminal 7800 into a desired shape.

  The operation button 7803 can have various functions such as time setting, power on / off operation, wireless communication on / off operation, manner mode execution and release, and power saving mode execution and release. . For example, the function of the operation button 7803 can be freely set by an operating system incorporated in the portable information terminal 7800.

  In addition, an application can be started by touching an icon 7804 displayed on the display portion 7001 with a finger or the like.

  Further, the portable information terminal 7800 can execute short-range wireless communication based on a communication standard. For example, a hands-free call can be made by communicating with a headset capable of wireless communication.

  Further, the portable information terminal 7800 may have an input / output terminal 7802. In the case of having the input / output terminal 7802, data can be directly exchanged with another information terminal via a connector. Further, charging can be performed through the input / output terminal 7802. Note that the charging operation of the portable information terminal exemplified in this embodiment may be performed by non-contact power transmission without using an input / output terminal.

  FIG. 15A illustrates the appearance of an automobile 7900. FIG. 15B shows a driver's seat of an automobile 7900. The automobile 7900 includes a vehicle body 7901, wheels 7902, a windshield 7903, lights 7904, a fog lamp 7905, and the like.

  The display device 10 of one embodiment of the present invention can be used for a display portion of an automobile 7900 or the like. For example, the display device 10 of one embodiment of the present invention can be provided in the display portions 7910 to 7917 illustrated in FIG.

  The display portion 7910 and the display portion 7911 are provided on the windshield 7903 of the automobile 7900. In one embodiment of the present invention, a display device in a so-called see-through state in which the opposite side can be seen through can be obtained by manufacturing an electrode included in a display device using a light-transmitting conductive material. If the display device is in a see-through state, the field of view is not obstructed even when the automobile 7900 is driven. Thus, the display device 10 of one embodiment of the present invention can be provided on the windshield 7903 of the automobile 7900. Note that in the case where a transistor or the like is provided in the display device, a light-transmitting transistor such as an organic transistor using an organic semiconductor material or a transistor using an oxide semiconductor is preferably used.

  The display portion 7912 is provided in the pillar portion. The display portion 7913 is provided in the dashboard portion. The display portion 7914 is provided on the door portion. For example, the field of view blocked by the pillar can be complemented by displaying an image from an imaging unit provided on the vehicle body on the display unit 7912. Similarly, the display portion 7913 can complement the view blocked by the dashboard, and the display portion 7914 can supplement the view blocked by the door. That is, by projecting an image from the imaging means provided outside the automobile, the blind spot can be compensated and safety can be improved. Also, by displaying a video that complements the invisible part, it is possible to confirm the safety more naturally and without a sense of incongruity.

  The display portion 7917 is provided on the handle. The display portion 7915, the display portion 7916, or the display portion 7917 can provide various other information such as navigation information, a speedometer, a tachometer, a travel distance, an oil supply amount, a gear state, and an air conditioner setting. In addition, display items and layouts displayed on the display unit can be appropriately changed according to the user's preference. Note that the above information can also be displayed on the display portions 7910 to 7914.

  Note that the display portions 7910 to 7917 can also be used as lighting devices.

  The display unit to which the display device 10 of one embodiment of the present invention is applied may be a flat surface. In this case, the display device 10 of one embodiment of the present invention may have a curved surface and no flexibility.

  FIG. 15C and FIG. 15D each show an example of digital signage (digital signage). The digital signage includes a housing 8000, a display portion 8001, a speaker 8003, and the like. Furthermore, an LED lamp, operation keys (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, and the like can be provided.

  FIG. 15D illustrates digital signage attached to a cylindrical column.

  The display device 10 of one embodiment of the present invention can be provided in the display portion 8001 illustrated in FIGS. 15C and 15D.

  The wider the display portion 8001, the more information can be provided at one time. In addition, the wider the display portion 8001, the easier it is for people to see, and for example, the advertising effectiveness of advertisements can be enhanced.

  By applying a touch panel to the display portion 8001, not only an image or a moving image is displayed on the display portion 8001, but also a user can operate intuitively, which is preferable. Moreover, when using for the use for providing information, such as route information or traffic information, usability can be improved by intuitive operation.

  FIG. 15E illustrates a laptop personal computer, which includes a housing 8111, a display portion 8112, a keyboard 8113, a pointing device 8114, and the like.

  The display device 10 of one embodiment of the present invention can be applied to the display portion 8112.

  This embodiment can be implemented in appropriate combination with at least part of the other embodiments described in this specification.

DESCRIPTION OF SYMBOLS 10 Display apparatus 11 Control part 12 Photometry part 13 Drive part 14 Display part 15a Driver 15b Driver 20 Pixel unit 21 Pixel 21B Display element 21G Display element 21R Display element 22 Pixel 22B Display element 22G Display element 22R Display element 25 Light 31 Calculation part 32 Storage unit 40 Liquid crystal element 51 Substrate 60 Light emitting element 60a Light emitting element 61 Substrate 62 Display unit 64 Circuit 65 Wiring 72 FPC
73 IC
100 Display panel 111a Conductive layer 111b Conductive layer 112 Liquid crystal 113 Conductive layer 117 Insulating layer 121 Insulating layer 130 Polarizing plate 131 Colored layer 132 Light shielding layer 133a Oriented film 133b Oriented film 134 Colored layer 141 Adhesive layer 142 Adhesive layer 191 Conductive layer 192 EL layer 192a EL layer 193 conductive layer 193a conductive layer 193b conductive layer 201 transistor 204 connecting portion 205 transistor 206 transistor 207 connecting portion 211 insulating layer 212 insulating layer 213 insulating layer 214 insulating layer 215 insulating layer 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 connection body 251 opening 252 connection part 311 electrode 311b electrode 340 liquid crystal element 360 light emitting element 360b light emitting element 360g light emitting element 3 60r light emitting element 360w light emitting element 362 display unit 400 display device 410 pixel 451 opening 7000 display unit 7001 display unit 7100 mobile phone 7101 case 7103 operation button 7104 external connection port 7105 speaker 7106 microphone 7107 camera 7110 mobile phone 7200 mobile information terminal 7201 case Body 7202 Operation button 7203 Information 7210 Portable information terminal 7300 Television apparatus 7301 Case 7303 Stand 7311 Remote control operation device 7400 Illumination apparatus 7401 Base part 7403 Operation switch 7411 Light emitting part 7500 Portable information terminal 7501 Case 7502 Pull-out member 7503 Operation button 7600 Carrying Information terminal 7601 Case 7602 Hinge 7650 Portable information terminal 7651 Non-display portion 7700 Portable information terminal 7701 Case 7 703a button 7703b button 7704a speaker 7704b speaker 7705 external connection port 7706 microphone 7709 battery 7800 portable information terminal 7801 band 7802 input / output terminal 7803 operation button 7804 icon 7805 battery 7900 automobile 7901 vehicle body 7902 wheel 7903 windshield 7904 light 7905 fog lamp 7910 display unit 7911 Display unit 7912 Display unit 7913 Display unit 7914 Display unit 7915 Display unit 7916 Display unit 7917 Display unit 8000 Housing 8001 Display unit 8003 Speaker 8111 Housing 8112 Display unit 8113 Keyboard 8114 Pointing device

Claims (8)

A driving method of a display device having a first display element and a second display element,
The first display element has a function of emitting visible light,
The second display element has a function of reflecting visible light,
A first step of displaying first display information on the first display element in a first period;
A second step of stopping the display of the first display information on the first display element;
And a second step of displaying second display information on the second display element in the second period,
After the first step, the first display information and the second display information are compared, and when the first display information and the second display information are the same, the second step and the second display information A method for driving a display device, comprising performing step 3. A driving method of a display device having a first display element and a second display element,
The first display element has a function of emitting visible light,
The second display element has a function of reflecting visible light,
A first step of displaying first display information on the first display element in a first period;
A second step of stopping the display of the first display information on the first display element;
And a second step of displaying second display information on the second display element in the second period,
After performing the first step n times (n is an integer equal to or greater than 1), the first display information and the second display information are compared, and the first display information and the second display information are compared. If the two are the same, the second step and the third step are performed. In claim 1 or claim 2,
The display device has a drive unit,
The drive unit supplies display information supplied to the first display element and display information supplied to the second display element at different timings. In claim 1 or claim 2,
The display device has a drive unit,
The driving unit supplies a display information supplied to the first display element and a display information supplied to the second display element at the same time. A display device having a first display element, a second display element, and a control unit,
The first display element has a function of emitting visible light,
When the first display information and the second display information are the same, the control unit stops the display of the first display element, and displays the second display information on the second display element. A display device having a function of causing A display device having a first display element, a second display element, and a control unit,
The first display element has a function of emitting visible light,
The second display element has a function of reflecting visible light,
The control unit compares the first display information with the second display information when the number of times the first display information is displayed on the first display element is n times or more, and compares the first display information with the first display information. When the information and the second display information are the same, the display of the first display element is stopped, and the second display element has a function of displaying the second display information. apparatus. In claim 5 or claim 6,
The display device has a drive unit,
The drive unit has a function of supplying display information to be supplied to the first display element and display information to be supplied to the second display element at different timings. In claim 5 or claim 6,
The display device has a drive unit,
The drive unit has a function of simultaneously supplying display information supplied to the first display element and display information supplied to the second display element.

Images