Display device

Abstract

The display device of the embodiment includes: a substrate; a driving transistor disposed on the substrate; a first insulating layer disposed on the driving transistor; a cathode electrode disposed on the first insulating layer; an organic layer including a light-emitting layer disposed on the cathode electrode; an anode electrode covering the organic layer; a second insulating layer disposed on the first insulating layer and having an opening overlapping with the cathode electrode; and a partition disposed on the second insulating layer. The anode electrode is electrically connected to the driving transistor via a first contact hole provided in the first and second insulating layers.

Description

[0001] This application claims priority based on Japanese patent application No. 2020-195811 (filing date: November 26, 2020), all the contents of which are incorporated herein by reference. Technical Field

[0002] The present invention relates to a display device. Background Art

[0003] In recent years, display devices using organic light emitting diodes (OLEDs) as display elements have been put into practical use. The display element has an organic layer between an anode electrode (pixel electrode) and a cathode electrode (common electrode). The organic layer includes a functional layer in addition to a light emitting layer.

[0004] The functional layers include, for example, electron injection layers, which are made of alkali metals (or alkali metal compounds) such as lithium fluoride and calcium and are easily degraded by moisture, etc. Such deterioration is a major cause of dark spots.

[0005] In a display device, a common structure is to configure an anode electrode on the array substrate side where a driving transistor is formed and a cathode electrode on the opposing substrate side. However, in such a structure, the electron injection layer is easily affected by moisture, etc., and there is a concern that environmental tolerance may be reduced. Summary of the invention

[0006] An object of the present invention is to provide a display device capable of achieving high environmental resistance.

[0007] A display device according to an embodiment includes: a substrate; a driving transistor disposed on the substrate; a first insulating layer disposed on the driving transistor; a cathode electrode disposed on the first insulating layer; an organic layer including a light-emitting layer disposed on the cathode electrode; an anode electrode covering the organic layer; a second insulating layer disposed on the first insulating layer and having an opening overlapping with the cathode electrode; and a partition disposed on the second insulating layer. The anode electrode is electrically connected to the driving transistor via a first contact hole provided in the first insulating layer and the second insulating layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a diagram showing an example of the structure of the display device according to the first embodiment.

[0009] Figure 2 A diagram for explaining the outline of a display device.

[0010] Figure 3 A diagram for explaining the structure of a display element.

[0011] Figure 4 It is a schematic plan view of pixels.

[0012] Figure 5 This is a diagram for explaining the cathode electrode.

[0013] Figure 6 It is a figure which shows the cross section which does not include the opening part formed in the cathode electrode.

[0014] Figure 7 It is a diagram for explaining a modification example of the partition wall.

[0015] Figure 8 It is a diagram for explaining a modification example of the partition wall.

[0016] Fig. 9 It is a diagram for explaining a modification example of the partition wall.

[0017] Fig.10 It is a diagram for explaining a modification example of the partition wall.

[0018] Fig.11 It is a diagram for explaining a modification example of the partition wall.

[0019] Fig.12 It is a diagram for explaining a modification example of the partition wall.

[0020] Fig.13 It is a diagram for explaining a modification example of the partition wall.

[0021] Fig.14 This is a diagram for explaining a covering member that covers the end portion of the cathode electrode.

[0022] Fig.15 This is a diagram for explaining a covering member that covers a contact hole.

[0023] Fig.16 The figure shows a cathode electrode divided into stripes.

[0024] Fig.17 A diagram showing a contact hole provided in an insulating layer overlapping with a display region.

[0025] Fig.18 This is a diagram showing an example of an organic layer and an anode electrode formed by another method.

[0026] Fig.19 It is a diagram further showing an example of an organic layer and an anode electrode formed by another method.

[0027] Fig. 20 This is a diagram showing an example of the layout of sub-pixels included in a pixel according to the second embodiment.

[0028] Fig.21 This is a diagram showing another example of the layout of sub-pixels included in a pixel.

[0029] Fig. 22 It is along Fig. 20 A schematic cross-sectional view of the display device taken along line CC′.

[0030] Fig.23 This is a diagram showing an example of a structure in which the arrangement of the cathode electrode and the anode electrode is replaced.

[0031] Description of Reference Numerals

[0032] DSP…display device; DA…display area, SA…peripheral area; PX…pixel; SP1, SP2, SP3…sub-pixel; CD, CD1, CD2, CD3…cathode electrode; AD, AD1, AD2, AD3…anode electrode; OR, OR1, OR2, OR3…organic layer; FL…power supply line; C…connecting electrode; CH1, CH2, CH3…contact hole; 10…array substrate (base material); 11, 12…insulating layer (first and second insulating layers); 13…partition wall; 20…display element; 501, 502…covering member, 601…groove. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0034] In addition, the disclosure is only an example, and the forms that can be easily thought of by those skilled in the art with respect to appropriate changes that maintain the main purpose of the invention are of course included in the scope of the present invention. In addition, the drawings schematically show the width, thickness, shape, etc. of each part compared with the actual form in order to make the description clearer, but it is only an example and does not limit the interpretation of the present invention. In addition, in this specification and each figure, the same reference numerals are given to the constituent elements that perform the same or similar functions as the constituent elements described in the previous figures, and repeated detailed descriptions are sometimes appropriately omitted.

[0035] In addition, in the accompanying drawings, as needed, mutually orthogonal X-axis, Y-axis and Z-axis are recorded to facilitate understanding. The direction along the X-axis is called the first direction X, the direction along the Y-axis is called the second direction Y, and the direction along the Z-axis is called the third direction Z. The surface defined by the X-axis and the Y-axis is called the X-Y plane, and the surface defined by the X-axis and the Y-axis is called the X-Z plane. The situation of observing the X-Y plane is called a plan view. In addition, in the present embodiment, the third direction Z is defined as up, and the direction on the opposite side of the third direction Z is defined as down. In the case of the so-called "second component above the first component" and "second component below the first component", the second component can be connected to the first component or can be separated from the first component.

[0036] The display device DSP of the present embodiment is an organic electroluminescent display device including an organic light emitting diode (OLED) as a display element, and is mounted in a television, a personal computer, a portable terminal, a mobile phone, and the like.

[0037] (First embodiment)

[0038] First, the first embodiment will be described. Figure 1 1 is a diagram showing an example of the structure of the display device DSP of the present embodiment. The display device DSP has a display area DA for displaying images and a peripheral area SA outside the display area DA on an insulating array substrate (substrate) 10. The array substrate 10 can be glass or a flexible resin film.

[0039] The display area DA includes a plurality of pixels PX arranged in a matrix in the first direction X and the second direction Y. As shown in FIG.

[0040] Here, a configuration example of a pixel PX is briefly described. The pixel PX includes a pixel circuit 1 and a display element 20. The pixel circuit 1 includes a pixel switch 2, a drive transistor 3, and a capacitor 4. The pixel switch 2 and the drive transistor 3 are switch elements composed of, for example, thin film transistors (TFT).

[0041] Regarding the pixel switch 2, the gate electrode is connected to the scanning line GL, the source electrode is connected to the signal line SL, and the drain electrode is connected to the electrode constituting one side of the capacitor 4 and the gate electrode of the driving transistor 3. Regarding the driving transistor 3, the source electrode is connected to the electrode constituting the other side of the capacitor 4 and the power supply line PL, and the drain electrode is connected to the anode electrode of the display element 20. The cathode electrode of the display element 20 is connected to the power supply line FL. In addition, the structure of the pixel circuit 1 is not limited to the example shown in the figure.

[0042] The display element 20 is an organic light emitting diode (OLED) as a light emitting element. In this embodiment, it is assumed that each of the plurality of pixels PX includes, for example, a display element 20 that emits light corresponding to the same wavelength. In this case, it is assumed that the display element 20 is configured to emit, for example, white light. In addition, the structure of the display element 20 will be described later.

[0043] According to such a display device DSP, the above-mentioned pixel circuit 1 (driving transistor 3 ) drives the pixel PX (display element 20 ), thereby being able to display an image in the display area DA.

[0044] Next, refer to Figure 2 The display device DSP of this embodiment is briefly described. The display device DSP of this embodiment is an organic electroluminescent display device as described above. In such a display device DSP, by supplying a driving current to an organic layer provided between an anode electrode (anode) and a cathode electrode (cathode), a light-emitting layer included in the organic layer can emit light. The anode electrode, the cathode electrode, and the organic layer constitute the above-mentioned display element 20. In addition, as Figure 2 As shown, the organic layer includes functional layers such as an electron injection layer, an electron transport layer, and a hole input layer in addition to the light-emitting layer, but the organic layer may also have a structure including other functional layers.

[0045] here, Figure 2 The left side of shows the positional relationship between the anode electrode, cathode electrode and organic layer of a conventional organic electroluminescent display device. Figure 2 As shown on the left side of FIG. 1 , in a conventional organic electroluminescent display device, an anode electrode, an organic layer, and a cathode electrode are sequentially arranged on an array substrate. In addition, an opposing substrate is arranged at a position opposite to the array substrate across the anode electrode, the organic layer, and the cathode electrode. The opposing substrate has light transmittance, and the light emitted from the display element 20 due to the light emission of the light emitting layer is recognized across the opposing substrate.

[0046] In addition, for example, an alkali metal or the like that is easily deteriorated by moisture or the like is used for the electron injection layer included in the organic layer. In a conventional organic electroluminescent display device, the electron injection layer is formed on the cathode electrode side. In addition, the material (electron transport material) that forms the electron transport layer disposed at a position in contact with the electron injection layer is generally highly active. Therefore, if Figure 2 If the anode electrode is arranged on the array substrate side and the cathode electrode is arranged on the opposing substrate side as shown on the left side of FIG. , the electron injection layer formed on the cathode electrode side is easily affected by moisture, etc., and the environmental tolerance is reduced.

[0047] Therefore, in the display device DSP (organic electroluminescent display device) of this embodiment, if Figure 2As shown on the right side of , a structure is adopted in which a cathode electrode is arranged on the array substrate side and an anode electrode is arranged on the opposing substrate side.

[0048] In the present embodiment, for convenience, the description is given assuming that a counter substrate is provided, but the counter substrate may be omitted, or a polarizing plate or the like may be provided instead of the counter substrate.

[0049] Below, refer to Figure 3 The structure of the display element 20 of this embodiment is described. In the display device DSP, the above-mentioned pixel circuit 1 is arranged on the array substrate 10. Figure 3 In FIG. 1 , only the driving transistor 3 included in the pixel circuit 1 is shown in a simplified manner.

[0050] The insulating layer 11 is disposed on the array substrate 10 so as to cover the driving transistor 3. The insulating layer 11 corresponds to a base layer of the display element 20, and is, for example, an organic insulating layer.

[0051] The insulating layer 12 is disposed on the insulating layer 11. The insulating layer 12 is, for example, an organic insulating layer. The insulating layer 12 is formed so as to divide the display element 20 or the pixels PX provided with the display element 20, and is sometimes called a rib, for example.

[0052] The display element 20 includes a cathode electrode CD, an organic layer OR, and an anode electrode AD. In the present embodiment, as described above, the cathode electrode CD is disposed on the array substrate 10 side, and the anode electrode AD is disposed on the counter substrate side (not shown).

[0053] The cathode electrode CD is an electrode commonly configured for a plurality of display elements 20 or a plurality of pixels PX provided in each of the plurality of display elements 20, and may be referred to as a common electrode, etc. The anode electrode AD is an electrode configured for each display element 20 or each pixel PX provided in the display element 20, and may be referred to as a pixel electrode, etc.

[0054] The cathode electrode CD is disposed on the insulating layer 11, and a portion thereof is covered by the insulating layer 12. The cathode electrode CD is electrically connected to a power supply line FL disposed in the peripheral area SA outside the display area DA, for example. Figure 3 As shown, the cathode electrode CD is connected to the power supply line FL via a contact hole CH1 formed in the insulating layer 11 overlapping the peripheral area SA. The power supply line FL is a wiring (auxiliary wiring) for supplying a common voltage to the cathode electrode CD.

[0055] In addition, the cathode electrode CD is a transparent electrode formed of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). In addition, the cathode electrode CD may also be a metal electrode formed of a metal material such as silver or aluminum. In addition, the cathode electrode CD may also be a laminate of a transparent electrode and a metal electrode. The cathode electrode CD may be, for example, a laminate in which a transparent electrode, a metal electrode, and a transparent electrode are laminated in sequence, or may be a laminate of three or more layers.

[0056] The insulating layer 12 has an opening OP overlapping with the cathode electrode CD in each pixel PX. The organic layer OR is disposed on the insulating layer 12 and is in contact with the cathode electrode CD via the opening OP. Figure 3 Although not shown, the organic layer OR includes a light-emitting layer and a functional layer as described above.

[0057] The anode electrode AD is formed so as to cover the organic layer OR. The anode electrode AD is, for example, a transparent electrode formed of a transparent conductive material such as ITO or IZO. In addition, the anode electrode AD may be an electrode formed of a metal thin enough to allow light to pass through, or an electrode formed by laminating the metal and the transparent conductive material, in addition to the transparent conductive material. In addition, the anode electrode AD may also be covered by a transparent protective film (including at least one of an inorganic insulating film and an organic insulating film).

[0058] Here, in this embodiment, the anode electrode AD disposed on the counter substrate side is electrically connected to the driving transistor 3 so that the display device DSP is driven by the design of the array substrate 10 (TFT array) similar to that of a general organic electroluminescent display device.

[0059] Specifically, a contact hole CH2 is formed to penetrate the insulating layers 11 and 12 to expose the driving transistor 3, and a connection electrode C is arranged on the contact hole CH2. The connection electrode C is formed on the insulating layer 12 along the periphery of the pixel PX from the contact hole CH2, and is connected to the end of the anode electrode AD. With such a structure, the anode electrode AD can be connected to the driving transistor 3 via the connection electrode C and the contact hole CH2. In addition, with respect to the contact hole CH2, the contact hole CH2 can be formed in the insulating layers 11 and 12 by different processes for each insulating layer, or the contact hole CH2 can be formed by penetrating the insulating layers 11 and 12 in one process after the insulating layers 11 and 12 are formed.

[0060] In the present embodiment, it is preferable that the anode electrode AD is in contact with (connected to) the connection electrode C, but the organic layer OR is not in contact with (not connected to) the connection electrode C.

[0061] In addition, Figure 3In the example shown, the anode electrode AD is connected to the driving transistor 3 via the connection electrode C and the contact hole CH2 , but the connection electrode C may be omitted as long as the anode electrode AD can be connected to the driving transistor 3 via the contact hole CH2 .

[0062] In addition, in this embodiment, a partition wall 13 is arranged at a position corresponding to the boundary between pixels PX on the connection electrode C (or the insulating layer 12). The partition wall 13 has an inverted tapered shape. Figure 3 The side surface of the partition wall 13 may be a plane inclined relative to the third direction Z, or may be a curved surface. In addition, the partition wall 13 may also be composed of a plurality of parts whose width gradually decreases from the top toward the bottom.

[0063] Furthermore, the partition wall 13 is formed so as to overlap with the insulating layer 12 in a plan view and divide the pixel PX. The above-mentioned organic layer OR is formed, for example, by anisotropic or directional vacuum deposition. When an organic material for forming the organic layer OR is, for example, deposited on the entire display area DA in a state where the partition wall 13 is arranged, the organic layer OR is hardly formed on the side surface of the partition wall 13 because the partition wall 13 has an inverted tapered shape. Thus, the organic layer OR can be formed so as to be partitioned by the partition wall 13 for each pixel PX.

[0064] In addition, the anode electrode AD is formed by a vacuum deposition method that is less directional or isotropic than the vacuum deposition method of the organic layer OR. In this case, the anode electrode AD covers the side and upper surfaces of the partition wall 13 and the insulating layer 12 under the eaves formed by the inverted taper of the partition wall 13, and the anode electrode AD is connected to the connection electrode C. Figure 3 Although not shown, when the organic layer OR and the anode electrode AD are formed as described above, the upper surface of the partition wall 13 is covered with the organic layer OR and the anode electrode AD.

[0065] In addition, although Figure 3 Although omitted in the figure, a counter substrate (insulating substrate) is bonded onto the anode electrode AD and the partition wall 13 , for example, via an adhesive or the like.

[0066] then, Figure 4 Here, the positional relationship of the above-mentioned opening OP, organic layer OR, anode electrode AD and connection electrode C in the plan view will be mainly described.

[0067] exist Figure 4In the figure, a frame 101 indicates an end of the opening OP (ie, a pixel opening), a frame 102 indicates an end of the organic layer OR (organic film end), and a frame 103 indicates an end of the anode electrode AD (anode end).

[0068] In this embodiment, the connection electrode C (contact wiring) is arranged to surround the opening OP and the organic layer OR (i.e., along the periphery of the pixel PX), and overlaps with the anode electrode AD and the contact hole CH2. Thus, the anode electrode AD is electrically connected to the driving transistor 3 arranged on the array substrate 10 via the connection electrode C and the contact hole CH2.

[0069] exist Figure 4 In the description, it is assumed that the connection electrode C is arranged along the outer periphery of the pixel PX. However, if the pixel PX is divided into a rectangular shape, the connection electrode C may be formed in a shape along at least one side of the pixel PX.

[0070] In addition, Figure 4 The middle contact hole CH2 is formed near the center of one side of the pixel PX, but the contact hole CH2 may be formed at, for example, a corner of the pixel PX as long as it is formed for each pixel PX.

[0071] Next, refer to Figure 5 The cathode electrode CD will be described. Figure 5 represents the cathode electrode CD in a plan view.

[0072] Since the cathode electrode CD is an electrode commonly arranged for a plurality of pixels PX (display element 20) as described above, it is formed uniformly throughout a plurality of pixels PX arranged in the display area DA. However, in the present embodiment, since the cathode electrode CD is arranged on the array substrate 10 side, Figure 5 As shown, an opening 201 for connecting the anode electrode AD to the driving transistor 3 is formed in the cathode electrode CD. In this embodiment, such an opening 201 is formed for each pixel PX, and a contact hole CH2 is formed to pass through the opening 201.

[0073] Furthermore, the cathode electrode CD is also formed at a position overlapping with the peripheral area SA, and is connected to the power supply line FL via a plurality of contact holes CH1 formed in the insulating layer 11 overlapping with the peripheral area SA.

[0074] exist Figure 5 In the description, it is assumed that the cathode electrode CD is connected to the power supply line FL via the plurality of contact holes CH1 , but the number and positions of the contact holes CH1 may be changed as appropriate.

[0075] In addition, the above Figure 3 Indicates that along Figure 5The cross section of the line AA' shown in FIG. 1 (including the cross section of the opening 201 formed in the cathode electrode CD). Figure 5 In the cross section of the line BB′ shown in FIG. 1 (excluding the cross section of the opening 201 formed in the cathode electrode CD), as shown in FIG. Figure 6 As shown, the contact hole CH2 is not formed, and the detailed description is omitted.

[0076] In addition, Figure 5 In the figure, a rectangular shape is shown as the shape of the opening 201 formed in the cathode electrode CD, but the shape of the opening 201 is not limited, and it may be a circular shape, for example. In addition, as long as the cathode electrode CD is arranged at a position overlapping with the opening OP of the insulating layer 12, and the contact hole CH2 can be formed, the size of the opening 201 is not limited. For example, when a light-transmitting substrate such as transparent polyimide is used as the array substrate 10, the transmittance of the display device DSP as a whole can be improved (i.e., transparent) by increasing the size of the opening 201. In this case, for example, the transmittance can be further improved by meshing the cathode electrode CD (formed by mesh wiring, etc.).

[0077] As described above, in this embodiment, the cathode electrode CD is arranged on the insulating layer 11 on the array substrate 10 (substrate), and the anode electrode AD is formed in a manner that covers the organic layer OR arranged on the cathode electrode CD. The anode electrode AD is electrically connected to the driving transistor 3 that drives the pixel PX via the contact hole CH2 (first contact hole) provided in the insulating layers 11 and 12 (first and second insulating layers).

[0078] Here, when the anode electrode AD is arranged on the array substrate 10 side and the cathode electrode CD is arranged on the opposite substrate side as in a conventional organic electroluminescent display device, the environmental tolerance becomes low. However, when the structure is simply made into a structure in which the cathode electrode CD is arranged on the array substrate 10 side and the anode electrode AD is arranged on the opposite substrate side, it is necessary to reverse the direction of the current flowing through the organic layer OR, so the design of the TFT array (array substrate 10) must be greatly changed, and there is a concern that a large cost will be incurred.

[0079] In contrast, in the present embodiment, since the anode electrode AD arranged on the opposing substrate side is connected to the driving transistor 3 via the contact hole CH2, even if the direction of the current flowing into the organic layer OR is opposite, the driving of each pixel PX (display element 20) can be achieved by the design of the TFT array used in a conventional organic electroluminescent display device.

[0080] Furthermore, in the present embodiment, the partition wall 13 is disposed at the boundary of two adjacent pixels PX (the first and second pixels) on the insulating layer 12 (or the connecting electrode C). With such a structure, for example, by vapor-depositing a suitable material for forming the organic layer OR and the anode electrode AD over a plurality of pixels PX, the display element 20 (the organic layer OR and the anode electrode AD) included in each pixel PX can be appropriately partitioned (divided) without using a fine mask or the like.

[0081] In addition, in the present embodiment, the connection resistance can be reduced by configuring the connection electrode C at a position along the periphery of the pixel PX and connecting (contacting) the anode electrode AD to the connection electrode C. Furthermore, in the present embodiment, the organic layer OR and the anode electrode AD are formed so that the anode electrode AD is in contact with the connection electrode C and the organic layer OR is not in contact with the connection electrode C (i.e., non-contacting), so that the contact area between the anode electrode AD and the connection electrode C can be ensured, and the generation of leakage current through the organic layer OR can be suppressed.

[0082] In the present embodiment, the cathode electrode CD is connected to the power supply line FL via the contact hole CH1 (second contact hole) provided in the insulating layer 11 overlapping the peripheral area SA, so that the common voltage can be appropriately supplied to the cathode electrode CD.

[0083] The following describes a modification of this embodiment. Figure 7 to Figure 13 , a modification example of the partition wall 13 used in this embodiment is described. Figure 7 to Figure 9 and Fig.13 Only the insulating layer 12 , the partition wall 13 , the connection electrode C, and the contact hole CH2 are shown.

[0084] In this embodiment, if Figure 3 Although the partition wall 13 is described as having an inverted tapered shape as shown, the partition wall 13 may also have, for example, Figure 7 The T-shape shown in the figure. Figure 7 The partition wall 13 shown also has a shape in which the width of the upper portion is larger than the width of the lower portion, similar to the above-mentioned inverse tapered shape, and thus can appropriately partition the pixel PX (the organic layer OR and the anode electrode AD).

[0085] When the partition wall 13 having a shape symmetrical (left-right symmetrical) about the third direction Z (ie, the normal direction of the main surface of the array substrate 10 ) is adopted, the stability of the partition wall 13 can be improved.

[0086] In addition, as the partition wall 13 having a bilaterally symmetrical shape, Figure 8 The partition wall 13 has the shape shown.

[0087] On the other hand, it is also possible to use, for example Fig. 9 The partition wall 13 having an inverted L shape as shown. When such a partition wall 13 having a shape that is not symmetrical (left-right asymmetrical) with respect to the third direction Z (i.e., the normal direction of the main surface of the array substrate 10) as an axis is adopted, by arranging the partition wall 13 close to the end side of the upper surface of the insulating layer 12, for example, in the first direction X, the area of ​​the connecting electrode C formed on the insulating layer 12 in a plan view can be increased.

[0088] here, Fig.10 Is adopted Fig. 9 The schematic plan view of the pixel PX in the case of the partition wall 13 shown in FIG. Figure 4 Although it is formed along the outer periphery of the pixel PX as shown in the figure, since the contact area with the anode electrode AD can be increased, the connection resistance can be reduced.

[0089] In addition, for example, when using Fig. 9 In the case of evaporating an organic material through the partition wall 13 shown in FIG. 1 , there is a situation in which the organic material goes around the partition wall 13 and enters the space 301 formed by the upper surface of the insulating layer 12 and the partition wall 13. Fig.11 As shown in the figure, an organic layer OR is formed to cover the connection electrode C arranged on the insulating layer 12.

[0090] In this case, by, for example, Fig.12 As shown in the figure, the connection electrode C is formed on each surface (side surface 401 and lower surface 402) of the partition wall 13 connected to the space 301. Even if the connection electrode C arranged on the upper surface of the insulating layer 12 is covered by the organic layer OR, the pixel PX (display element 20) can be driven because the anode electrode AD is in contact with the connection electrode C formed on the side surface 401 of the partition wall 13. In the case where the anode electrode AD is further formed in a manner of contacting the connection electrode C formed on the lower surface 402 of the partition wall 13, the contact area between the anode electrode AD and the connection electrode C can be further increased.

[0091] In addition, as the partition wall 13 having a left-right asymmetrical shape, a partition wall having Fig.13 The partition wall 13 has a shape (trapezoidal shape) as shown.

[0092] Next, a modification example of the cathode electrode CD used in this embodiment is described. First, in this embodiment, as in Figure 5As described in , an opening 201 is formed in the cathode electrode CD for each pixel PX, and the contact hole CH2 passes through the opening 201. However, according to such a structure, since the contact hole CH2 is close to the cathode electrode CD, a strong electric field may be generated. In this case, the electrochemical reaction is promoted, and there is a concern that the cathode electrode CD may corrode or melt.

[0093] Therefore, in this embodiment, for example, Fig.14 As shown in FIG. 1 , the end (edge) of the cathode electrode CD forming the opening 201 is covered by the covering member 501 (that is, the covering member 501 covers the end of the cathode electrode CD). In this case, the covering member 501 may be formed to cover the end of the cathode electrode CD facing the contact hole CH2. Fig.15 As shown in FIG. 1 , the contact hole CH2 is covered with the cover member 502 (that is, the cover member 502 covers the inner surface of the contact hole CH2).

[0094] In this case, the covering members 501 and 502 may be formed of the same material as the insulating layer 11 (or the insulating layer 12), for example, a material having high insulating and covering properties such as silicon oxide (SiO), silicon nitride (SiN) or insulating polymer. In addition, a structure in which both the covering members 501 and 502 are formed may be used.

[0095] This structure can prevent, for example, metal ions eluted from the cathode electrode CD from penetrating through the interface between the insulating layer 11 (planarizing layer) and the insulating layer 12 (rib) to connect (short-circuit) the cathode electrode CD and the anode electrode AD.

[0096] In addition, in the present embodiment, a case where the cathode electrode CD is formed over the plurality of pixels PX arranged in the display area DA is described, but the cathode electrode CD may be formed as follows, for example. Fig.16 In this case, a contact hole CH1 for connecting the cathode electrode CD to the power supply line FL may be formed for each cathode electrode CD divided into stripes.

[0097] Here, the case where the cathode electrode CD is divided into stripes is described, but the cathode electrode CD may be divided, for example, for each pixel PX or for each plurality of adjacent pixels PX.

[0098] In addition, when the cathode electrode CD is divided and formed as described above, the cathode electrode CD may be formed as follows. Fig.17 As shown in FIG. 1 , the power supply line FL is connected via a contact hole CH3 (third contact hole) provided in the insulating layer 11 overlapping the display area DA where the pixel PX is arranged. Figure 3 As shown in the figure, since the contact hole CH1 is provided in the peripheral area SA, the peripheral area SA can be reduced in size and the frame can be narrowed.

[0099] In this embodiment, a case where a common voltage is supplied to the cathode electrode CD via the power supply line FL is described, but when the cathode electrode CD is divided as described above, a structure in which a different voltage is supplied to each cathode electrode CD (ie, pixel PX) can be made.

[0100] Furthermore, in the case where the cathode electrode CD is divided and formed, for example, a structure as follows can be made, namely: the cathode electrode CD is arranged on the array substrate 10 side in a specified pixel PX (the first pixel), and the anode electrode AD is arranged on the array substrate 10 side in a pixel PX (the second pixel) different from the pixel PX.

[0101] Here, in this embodiment, the case where the pixel PX (organic layer OR and anode electrode AD) is partitioned (divided) by the partition wall 13 arranged on the insulating layer 12 is described, but the organic layer OR and anode electrode AD can also be formed by, for example, patterning using a fine mask or etching after full-surface film formation. In the case of such a structure, for example, Fig.18 In this way, the organic layer OR and the anode electrode AD are formed.

[0102] Furthermore, the organic layer OR and the anode electrode AD may also be as follows, for example. Fig.19 As shown in FIG. 1 , the insulating layer 12 is formed by providing a groove 601 in the insulating layer 12. In addition, the groove 601 has a shape in which the width of the lower part (bottom) is larger than the width of the upper part. In addition, the side surface of the groove 601 is inclined, for example, relative to the third direction Z. According to such a groove 601, when the material for forming the organic layer OR and the anode electrode AD is evaporated over a plurality of pixels PX, the organic layer OR and the anode electrode AD (that is, the pixel PX) can be isolated at the portion of the groove 601.

[0103] In addition, in the present embodiment, a case where a plurality of pixels PX are respectively provided with a display element 20 that emits light corresponding to the same wavelength is described, and a case where the display element 20 emits white light (i.e., the luminescent color is white) is assumed. In this case, for example, by providing the display device DSP with color filters colored in red, green, and blue at a position opposite to the display element 20 (a position in the direction of the opposing substrate), red, green, and blue light can be emitted from each pixel PX, so that multi-color display can be performed.

[0104] Furthermore, when the display element 20 emits ultraviolet light (that is, the luminescent color is ultraviolet light), multi-color display can be achieved by arranging a light conversion layer at a position facing the display element 20 .

[0105] (Second embodiment)

[0106] Next, the second embodiment will be described. In the following description, detailed descriptions of the same parts as the first embodiment will be omitted. Here, the parts different from the first embodiment will be mainly described.

[0107] In the first embodiment described above, a case is described where a plurality of pixels PX are respectively provided with display elements 20 that emit light corresponding to the same wavelength (i.e., a plurality of pixels PX display the same color), but the present embodiment is different from the first embodiment described above in that a plurality of pixels PX are respectively provided with sub-pixels SP1, SP2, and SP3 that display different colors. In one example, the pixel PX is provided with a sub-pixel SP1 that displays red, a sub-pixel SP2 that displays green, and a sub-pixel SP3 that displays blue. In addition, the pixel PX may also be provided with four or more sub-pixels that are provided with sub-pixels of other colors such as white in addition to the above three sub-pixels.

[0108] When the pixel PX is configured to include the sub-pixels SP1 , SP2 , and SP3 as described above, the sub-pixels SP1 , SP2 , and SP3 each include the pixel circuit 1 and the display element 20 described in the first embodiment.

[0109] here, Fig. 20 1 is a diagram showing an example of the layout of sub-pixels included in a pixel PX. Here, the description will focus on four pixels PX.

[0110] The sub-pixel SP1, the sub-pixel SP2, and the sub-pixel SP3 constituting one pixel PX are respectively formed into a substantially rectangular shape extending in the second direction Y, and are arranged in the first direction X. When focusing on two pixels PX arranged in the first direction X, the display colors of the adjacent sub-pixels are different from each other. In addition, when focusing on two pixels PX arranged in the second direction Y, the display colors of the adjacent sub-pixels are the same. In addition, the areas of the sub-pixels SP1, the sub-pixels SP2, and the sub-pixels SP3 may be the same or different from each other.

[0111] Fig.21: is a diagram showing another example of the layout of sub-pixels included in a pixel PX. Sub-pixels SP1 and SP2 constituting one pixel PX are arranged in the second direction Y, sub-pixels SP1 and SP3 are arranged in the first direction X, and sub-pixels SP2 and SP3 are arranged in the first direction X. Sub-pixel SP1 is formed into a substantially rectangular shape extending in the first direction X, and sub-pixels SP2 and SP3 are formed into substantially rectangular shapes extending in the second direction Y. The area of ​​sub-pixel SP2 is larger than that of sub-pixel SP1, and the area of ​​sub-pixel SP3 is larger than that of sub-pixel SP2. In addition, the area of ​​sub-pixel SP1 may be the same as that of sub-pixel SP2.

[0112] Focusing on two pixels PX arranged in the first direction X, in a region where sub-pixels SP1 and sub-pixels SP3 are alternately arranged and in a region where sub-pixels SP2 and sub-pixels SP3 are alternately arranged, the display colors of adjacent sub-pixels are different from each other.

[0113] Focusing on two pixels PX arranged in the second direction Y, in a region where sub-pixels SP1 and sub-pixels SP2 are alternately arranged, the display colors of adjacent sub-pixels are different from each other. In addition, in a region where a plurality of sub-pixels SP3 are arranged, the display colors of adjacent sub-pixels are the same.

[0114] in addition, Fig. 20 and Fig.21 The outer shape of each sub-pixel shown in the figure corresponds to, for example, the outer shape of the anode electrode AD of the display element 20 or the light emitting region (opening OP) of the display element 20. Fig. 20 and Fig.21 The shapes of the sub-pixels SP1 , SP2 , and SP3 are simplified for the purpose of explaining the layout, and do not necessarily reflect the actual shapes.

[0115] the following, Fig. 22 It is along Fig. 20 In the first embodiment described above, the display element 20 includes a cathode electrode CD, an organic layer OR and an anode electrode AD, and the organic layer OR includes a light-emitting layer that emits light of the same color (that is, all pixels PX display the same color). In the present embodiment, organic layers OR1, OR2 and OR3 including light-emitting layers that emit light of different colors are formed.

[0116] Specifically, in the region overlapping with the sub-pixel SP1, an organic layer OR1 including a light-emitting layer emitting red light is formed, for example, and the organic layer OR1 is arranged on the cathode electrode CD1 arranged on the side of the array substrate 10 and covered by the anode electrode AD1. The cathode electrode CD1, the organic layer OR1, and the anode electrode AD1 correspond to the display element 20R included in the sub-pixel SP1.

[0117] In addition, in the region overlapping with the sub-pixel SP2, for example, an organic layer OR2 including a light-emitting layer emitting green light is formed, and the organic layer OR2 is arranged on the cathode electrode CD2 arranged on the side of the array substrate 10 and covered by the anode electrode AD2. The cathode electrode CD2, the organic layer OR2, and the anode electrode AD2 correspond to the display element 20G included in the sub-pixel SP2.

[0118] Furthermore, in the region overlapping with the sub-pixel SP3, for example, an organic layer OR3 including a light-emitting layer emitting blue light is formed, and the organic layer OR3 is arranged on the cathode electrode CD3 arranged on the side of the array substrate 10 and covered by the anode electrode AD3. The cathode electrode CD3, the organic layer OR3, and the anode electrode AD3 correspond to the display element 20B included in the sub-pixel SP3.

[0119] In addition, the anode electrodes AD1, AD2 and AD3 are respectively connected to the driving transistors 3 provided for each sub-pixel SP1, SP2 and SP3 via the contact holes CH2. Since this is the same as the anode electrodes AD and the contact holes CH2 described in the first embodiment, their detailed description is omitted here.

[0120] Here, in this embodiment, it is possible to Figure 5 As shown in FIG. 1 , the cathode electrode CD is formed over a plurality of pixels PX (sub-pixels SP1, SP2, and SP3) arranged in the display area DA, but in Fig. 22 In this case, the cathode electrodes CD1, CD2 and CD3 may be connected to the power supply line FL via contact holes CH3 provided in the insulating layer 11 overlapping with the regions where the sub-pixels SP1, SP2 and SP3 are arranged.

[0121] In addition, the case where the cathode electrodes CD1, CD2, and CD3 are formed by dividing for each sub-pixel is described here, but the cathode electrode CD1 may be formed in common for a plurality of sub-pixels SP1, for example. Similarly, the cathode electrode CD2 may be formed in common for a plurality of sub-pixels SP2, and the cathode electrode CD3 may be formed in common for a plurality of sub-pixels SP3. That is, in the present embodiment, the cathode electrodes CD1, CD2, and CD3 may be provided in accordance with the luminescent color (i.e., display color) of each organic layer.

[0122] In the case of such a configuration, different voltages corresponding to display colors can be supplied to the cathode electrodes CD1 , CD2 , and CD3 .

[0123] Furthermore, in this embodiment, the cathode electrode and the anode electrode may be arranged in a different arrangement in at least one of the plurality of sub-pixels SP1, SP2, and SP3. With such a structure, for example, an optimal stacking structure can be adopted for each sub-pixel SP1, SP2, and SP3 according to the luminescent color of the organic layer.

[0124] Here, for example, the sub-pixel SP3 displaying blue has a case where the driving of the display element 20B (organic layer OR3) is unstable compared to the other sub-pixels SP1 and SP2. In this case, in the sub-pixel SP3, in order to improve the environmental tolerance of the organic layer OR3, a structure in which the cathode electrode CD3 is arranged on the array substrate 10 side can be adopted. On the other hand, it can be imagined that if the cathode electrode is arranged on the array substrate 10 side, the driving efficiency (luminous efficiency) of the display element 20 decreases. Therefore, in the sub-pixels SP1 and SP2, a structure in which the anode electrodes AD1 and AD2 are arranged on the array substrate 10 side can be adopted. In addition, Fig.23 As described above, the cathode electrode CD3 is arranged on the array substrate 10 side in the sub-pixel SP3 , and the anode electrodes AD1 and AD2 are arranged on the array substrate 10 side in the sub-pixels SP1 and SP2 .

[0125] In addition, in the case of a manufacturing process in which an organic layer is formed for each luminescent color, for example, it is assumed that an organic layer OR1 emitting red light is formed first. In this case, the organic layer OR1 may be affected by external air or the like during the formation of other organic layers OR2 and OR3. In such a case, for example, environmental tolerance can be improved by arranging the cathode electrode CD1 on the array substrate 10 side in the sub-pixel SP1.

[0126] According to the above-described embodiments, a display device capable of achieving high environmental resistance can be provided.

[0127] All display devices that can be implemented by appropriately changing the design of the display devices described above as the embodiments of the present invention by a person skilled in the art belong to the scope of the present invention as long as they include the gist of the present invention.

[0128] In the scope of the present invention, those skilled in the art can think of various variations, which also belong to the scope of the present invention. For example, those skilled in the art appropriately add, delete or design changes the components of the above-mentioned embodiment to obtain a form, or add, omit or change the conditions of the process to obtain a form, as long as they have the gist of the present invention, they are also included in the scope of the present invention.

[0129] In addition, regarding other effects brought about by the forms described in the above embodiments, effects that are clear from the description of this specification or effects that can be appropriately conceived by those skilled in the art should of course be understood to be brought about by the present invention.

Claims

1. A display device having a plurality of pixels, characterized in that: have: Base material; A driving transistor is disposed on the substrate; A first insulating layer is disposed on the driving transistor; A cathode electrode, disposed on the first insulating layer; An organic layer including a light-emitting layer is disposed on the cathode electrode; an anode electrode, covering the organic layer; a second insulating layer disposed on the first insulating layer and having an opening overlapping with the cathode electrode; as well as A partition wall is arranged on the second insulating layer; The anode electrode is provided in each of the plurality of pixels, and the anode electrode is electrically connected to the driving transistor via a first contact hole provided in the first insulating layer and the second insulating layer for each of the pixels; The partition wall has an inverted tapered shape.

2. The display device according to claim 1, wherein: The partition wall has a shape in which the width of the upper portion is larger than the width of the lower portion.

3. The display device according to claim 2, wherein: The partition wall has a shape that is symmetrical about a normal direction of a main surface of the substrate.

4. The display device according to claim 2, wherein: The partition wall has a shape that is not symmetrical about the normal direction of the main surface of the substrate.

5. The display device according to claim 1, wherein: The anode electrode is connected to a connection electrode arranged at a position surrounding the organic layer in a plan view; The connection electrode is connected to the driving transistor via the first contact hole.

6. The display device according to claim 5, characterized in that The organic layer is not in contact with the connecting electrode.

7. The display device according to claim 1, wherein: The cathode electrode is connected to a wiring that supplies a voltage to the cathode electrode via a second contact hole provided in the first insulating layer overlapping a peripheral region where no pixels are arranged.

8. The display device according to claim 1, wherein: The cathode electrode is connected to a wiring that supplies a voltage to the cathode electrode via a third contact hole provided in the first insulating layer overlapping a display region where pixels are arranged.

9. The display device according to claim 1, wherein: The display device further includes an insulating member covering an end portion of the cathode electrode facing the first contact hole.

10. The display device according to claim 1, wherein: The display device further includes an insulating member covering an inner surface of the first contact hole.

11. The display device according to claim 1, wherein: In a region overlapping with the first pixel, the cathode electrode is disposed on the first insulating layer, and the anode electrode covers the organic layer; In a region overlapping with a second pixel different from the first pixel, the anode electrode is arranged on the first insulating layer, and the cathode electrode covers the organic layer.

12. The display device according to claim 11, wherein: In a region overlapping with the first pixel, a cathode electrode disposed on the first insulating layer is supplied with a first voltage; In a region overlapping with the second pixel, a second voltage is supplied to the cathode electrode covering the organic layer.

13. The display device according to claim 11 or 12, characterized in that: The organic layer arranged in the region overlapping the first pixel and the organic layer arranged in the region overlapping the second pixel each include a light emitting layer emitting light of the same color.

14. The display device according to claim 11 or 12, characterized in that: The organic layer arranged in the region overlapping the first pixel and the organic layer arranged in the region overlapping the second pixel include light emitting layers emitting light of different colors, respectively.

15. A display device having a plurality of pixels, characterized in that: have: Base material; A driving transistor is disposed on the substrate; A first insulating layer is disposed on the driving transistor; A cathode electrode, disposed on the first insulating layer; An organic layer including a light-emitting layer is disposed on the cathode electrode; an anode electrode, covering the organic layer; as well as a second insulating layer disposed on the first insulating layer and having an opening overlapping with the cathode electrode; The anode electrode is provided in each of the plurality of pixels, and the anode electrode is electrically connected to the driving transistor via a contact hole provided in the first insulating layer and the second insulating layer for each of the pixels.

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