JP6752844B2 - Organic EL display device - Google Patents

Description

The present invention relates to an organic EL display device.

As one of the display devices, an organic EL display device using an organic EL material (EL: Electro-Luminescence) as a light emitting substance can be mentioned. This organic EL display device may have a touch panel. For example, Patent Document 1 below discloses a method of bonding two glass panel materials. In Patent Document 1 below, a display element such as an LCD element or an EL element is provided on a glass substrate in one of the glass panel materials. Further, in the other glass panel material, a touch panel is provided on the glass substrate.

Japanese Unexamined Patent Publication No. 2012-136622

In Patent Document 1, the display element and the touch panel are provided on different glass substrates, and the glass substrates are integrated with each other. In this case, the number of parts of the final product is increased as compared with the product without the touch panel.

An object of the present invention is to provide an organic EL display device capable of exhibiting a touch panel function while reducing the number of parts.

The organic EL display device according to one aspect of the present invention has a substrate having main surfaces extending along a first direction and a second direction intersecting with each other, and is located on the substrate and extends along the first direction. The first electrode layer and the second electrode layer, the first organic EL layer located on the first electrode layer, the second organic EL layer located on the second electrode layer, and the position on the first organic EL layer. A third electrode layer extending along the second direction and a fourth electrode layer located on the second organic EL layer and extending along the second direction are provided with the first electrode layer. The second electrode layer is opposed to each other in the first direction and is separated from each other. The first electrode layer also functions as a first touch electrode, and the second electrode layer is different from the first touch electrode. It also functions as a different second touch electrode.

According to this organic EL display device, the first electrode layer also functions as a first touch electrode, and the second electrode layer also functions as a second touch electrode different from the first touch electrode. Therefore, the touch panel function can be exhibited without attaching the substrate on which the touch panel is formed to the organic EL display device. Therefore, the touch panel function can be exhibited while reducing the number of parts. In addition, the first electrode layer and the second electrode layer face each other in the first direction and are separated from each other. Therefore, the sensing region in the first direction can be separated into two. As a result, the number of sensing regions can be increased. Here, the first electrode layer and the second electrode layer may be located on a straight line extending along the first direction.

The organic EL display device may further include an insulating film that fills the gap between the first electrode layer and the second electrode layer in the first direction. In this case, since the first electrode layer and the second electrode layer can be reliably insulated, the yield can be improved.

The organic EL display device is located on an insulating film and further includes a partition wall separating the first organic EL layer and the second organic EL layer, and the width of the partition wall along the first direction is along the first direction. It may be longer than the width of the gap. In this case, it is possible to prevent the gap between the first electrode layer and the second electrode layer from affecting the display of the organic EL display device.

The organic EL display device further includes a drive circuit connected to the first electrode layer, the second electrode layer, the third electrode layer, and the fourth electrode layer, and the drive circuit is the first at the first timing. A signal for controlling the light emission of each of the 1 organic EL layer and the 2nd organic EL layer is transmitted to the 1st electrode layer, the 2nd electrode layer, the 3rd electrode layer, and the 4th electrode layer, and the second timing In, the presence or absence of an object in contact with the surface opposite to the main surface of the substrate may be detected via the first electrode layer and the second electrode layer. In this case, light emission control of each organic EL layer and detection of an object in contact with the substrate can be realized by a single drive circuit. As a result, the number of parts can be further reduced. Here, the drive circuit may detect the presence or absence of a change in the capacitances of the first electrode layer and the second electrode layer at the second timing.

According to the present invention, it is possible to provide an organic EL display device capable of exhibiting a touch panel function while reducing the number of parts.

FIG. 1 is a schematic plan view of the organic EL display device according to the present embodiment. FIG. 2 is a schematic cross-sectional view taken along the line AA of FIG. FIG. 3 is a flowchart for explaining a driving method of the organic EL display device. FIG. 4 is a schematic perspective view of the organic EL display device according to the modified example.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals will be used for the same elements or elements having the same function, and duplicate description will be omitted.

First, the configuration of the organic EL display device according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic plan view of the organic EL display device according to the present embodiment. FIG. 2 is a schematic cross-sectional view taken along the line AA of FIG.

As shown in FIGS. 1 and 2, the organic EL display device 1 according to the present embodiment is a passive matrix type display device. The organic EL display device 1 includes a substrate 2, a display unit 3, wiring units 4 to 7, an integrated circuit 8, and an FPC 9 (flexible printed circuit board).

The substrate 2 is an element substrate provided with a display unit 3 and wiring units 4 to 7. The substrate 2 is, for example, a glass substrate or a flexible substrate (for example, a plastic substrate) and has translucency. The main surface 2a of the substrate 2 has, for example, a substantially rectangular shape. A protective film or the like exhibiting translucency and insulation may be formed on the main surface 2a. From the viewpoint of the accuracy of touch sensing via the substrate 2, the thickness of the protective film is, for example, 10 nm or more and 100 nm or less. In the following, the short side direction of the main surface 2a is the direction X (first direction), and the long side direction of the main surface 2a is the direction Y (second direction). The directions X and Y intersect each other. Further, the direction orthogonal to the directions X and Y is defined as the direction Z. The direction Z corresponds to the thickness direction of the substrate 2.

The display unit 3 is a portion that generates light when a current is supplied, and is provided on the main surface 2a of the substrate 2. The display unit 3 has a plurality of organic EL elements 11 arranged in a matrix, an insulating film 12, and a plurality of partition walls 13. In the present embodiment, the organic EL element 11 connected to the wiring portion 4 is referred to as an organic EL element 11a, and the organic EL element 11 connected to the wiring portion 5 is referred to as an organic EL element 11b. The term "connection" as used herein includes not only physical connection but also electrical connection and functional connection.

The organic EL element 11a has an anode layer (first electrode layer) 21, an organic EL layer (first organic EL layer) 22, and a cathode layer (third electrode layer) 23. In the present embodiment, the anode layer 21, the organic EL layer 22, and the cathode layer 23 are laminated in order from the substrate 2 side.

The anode layer 21 is a transparent conductive layer located on the main surface 2a of the substrate 2 and extending along the direction X. In FIG. 1, a part of the anode layer 21 is shown by a broken line. The anode layer 21 is located, for example, on the wiring portion 4 side of the center of the substrate 2 in the direction X. The plurality of anode layers 21 are arranged at intervals along the direction Y on the wiring portion 4 side from the center of the substrate 2 in the direction X. The distance between the anode layers 21 adjacent to each other along the direction Y is, for example, 10 μm or more and 30 μm or less. As the material constituting the anode layer 21, for example, a conductive material exhibiting translucency such as ITO (indium tin oxide) and IZO (zinc oxide) is used. The thickness of the anode layer 21 is, for example, 50 nm or more and 300 nm or less. The anode layer 21 is formed by patterning a transparent conductive film formed on the main surface 2a by a PVD method (physical vapor deposition method) such as a vacuum deposition method or a sputtering method.

The organic EL layer 22 is located on the anode layer 21 and includes at least an organic light emitting layer containing a light emitting material. The organic EL layer 22 may have an electron injection layer, an electron transport layer, a hole transport layer, a hole injection layer, and the like in addition to the organic light emitting layer. The light emitting material may be a low molecular weight organic compound or a high molecular weight organic compound. As the light emitting material, a fluorescent material may be used, or a phosphorescent material may be used. The electron injection layer, the electron transport layer, the hole transport layer, and the hole injection layer each contain an organic material. For example, the hole transport layer contains α-NPD, which is a low molecular weight organic compound exhibiting hole transportability, and the electron transport layer contains Alq ₃ , which is a low molecular weight organic compound exhibiting electron transportability. The thickness of the organic EL layer 22 is, for example, 100 nm or more and 300 nm or less. The organic EL layer 22 is formed by, for example, the PVD method.

The cathode layer 23 is a conductive layer located on the organic EL layer 22 and extending along the direction Y. The cathode layer 23 is located, for example, on the wiring portion 4 side of the center of the substrate 2 in the direction X. The plurality of cathode layers 23 are arranged at intervals along the direction X on the wiring portion 4 side from the center of the substrate 2 in the direction X. The distance between the cathode layers 23 adjacent to each other along the direction X is, for example, 10 μm or more and 30 μm or less. The material (conductive material) constituting the cathode layer 23 is, for example, a metal such as aluminum or silver. The conductive material may contain an alkaline earth metal (magnesium, calcium, etc.), or may contain a translucent material such as IZO (indium zinc oxide) and ITO (indium tin oxide). Good. The conductive material may include a plurality of conductive materials. The thickness of the cathode layer 23 is, for example, 50 nm or more and 300 nm or less. The cathode layer 23 is formed by, for example, the PVD method.

The organic EL element 11b has the same configuration as the organic EL element 11a. Specifically, the organic EL element 11b has an anode layer (second electrode layer) 31, an organic EL layer (second organic EL layer) 32, and a cathode layer (fourth electrode layer) 33.

The anode layer 31 is a transparent conductive layer formed at the same time as the anode layer 21, is located on the main surface 2a of the substrate 2, and extends along the direction X. In FIG. 1, a part of the anode layer 31 is shown by a broken line. The anode layer 31 is located, for example, on the wiring portion 5 side of the center of the substrate 2 in the direction X. The plurality of anode layers 31 are arranged at intervals along the direction Y on the wiring portion 5 side from the center of the substrate 2 in the direction X. The distance between the anode layers 31 adjacent to each other along the direction Y is, for example, 10 μm or more and 30 μm or less.

The anode layer 21 and the anode layer 31 are not arranged with each other along the direction Y. The anode layers 31 face each other and are separated from each other in the direction X with respect to the corresponding anode layers 21. Therefore, the anode layer 21 and the anode layer 31 facing each other in the direction X are located on one straight line extending along the direction X. In the present embodiment, the central axes of the anode layers 21 and 31 along the direction X overlap each other and are located on the straight line. A gap S is provided between the anode layer 21 and the anode layer 31 in the direction X. Specifically, a gap S is provided between the center-side end of the anode layer 21 in the direction X and the center-side end of the anode layer 31 in the direction X. Due to the presence of the gap S, the anode layers 21 and 31 are electrically separated. The width W of the gap S along the direction X is, for example, 10 μm or more and 30 μm or less. The length of the anode layer 31 along the direction X may be substantially the same as or different from the length of the anode layer 21 along the direction X. The length (width) of the anode layer 31 along the direction Y is substantially the same as the length (width) of the anode layer 21 along the direction Y. In addition, "substantially the same" in the present embodiment is a concept that does not only indicate exactly the same, but also includes some errors (for example, about several% at the maximum).

The organic EL layer 32 is a layer formed at the same time as the organic EL layer 22, and is located on the anode layer 31. Therefore, the organic EL layer 32 has the same layer structure as the organic EL layer 22. The cathode layer 33 is a conductive layer formed at the same time as the cathode layer 23, is located on the organic EL layer 32, and extends along the direction Y. The cathode layer 33 is located, for example, on the wiring portion 5 side of the center of the substrate 2 in the direction X. The plurality of cathode layers 33 are arranged at intervals along the direction X on the wiring portion 5 side from the center of the substrate 2 in the direction X. The distance between the cathode layers 33 adjacent to each other along the direction X is, for example, 10 μm or more and 30 μm or less. The distance between the adjacent cathode layers 23 and 33 along the direction X is also, for example, 10 μm or more and 30 μm or less.

The insulating film 12 is an insulating member that prevents an undesired (unintended) short circuit of each organic EL element 11 provided in the display unit 3. The insulating film 12 may be, for example, an inorganic insulating film such as a silicon oxide film or a silicon nitride film, or an organic insulating film such as a polyimide resin film, a cycloolefin resin film, or an acrylic resin film. The thickness of the insulating film 12 is, for example, 50 nm or more and 3000 nm (3 μm) or less. The insulating film 12 is provided so as to fill the gap S between the anode layers 21 and 31. Therefore, the insulating film 12 is provided after the formation of the anode layers 21 and 31 and before the formation of the organic EL layers 22 and 32.

The partition wall 13 is an element separator that separates each cathode layer 23 and each cathode layer 33 in the display unit 3, and exhibits insulating properties. The partition wall 13 is located on the insulating film 12 and extends along the direction Y, and has an inverted tapered cross section. In the present embodiment, the width of the partition wall 13 along the direction X is, for example, 10 μm or more and 30 μm or less, which is longer than the width W of the gap S between the anode layers 21 and 31. In this case, the distance between the adjacent organic EL layers 22 and 32 along the direction X is along the distance between the adjacent organic EL layers 22 along the direction X, and along the direction X between the adjacent organic EL layers 32. Can be the same as the interval. Therefore, it is possible to prevent the gap S from affecting the display of the organic EL display device 1. As a specific example, by forming the gap S, it is possible to prevent the screen in the display unit 3 from being visually recognized as if it is divided into two in the direction X. The partition wall 13 is provided after the formation of the insulating film 12 and before the formation of the organic EL layers 22 and 32. Therefore, by forming the organic EL layers 22, 32 and the cathode layers 23, 33 by the PVD method after the partition wall 13, the organic EL layers 22, 32 and the cathode layers 23, 33 are formed into a desired shape by the partition wall 13. It is patterned. The partition wall 13 contains, for example, a negative type photosensitive resin.

The display unit 3 also functions as a touch panel unit that detects a conductive object (for example, a finger or the like) that comes into contact with the substrate 2. When the display unit 3 functions as a touch panel unit, each of the anode layers 21 and 31 functions as a touch electrode. That is, the anode layer 21 also functions as a first touch electrode, and the anode layer 31 also functions as a second touch electrode different from the first touch electrode. The display unit 3 is set with a plurality of first sensing regions T1 located on the wiring unit 4 side in the direction X and a plurality of second sensing regions T2 located on the wiring unit 5 side in the direction X. Each first sensing region T1 is arranged along the direction Y and includes a plurality of anode layers 21. Each first sensing region T1 includes, for example, one or more and 256 or less anode layers 21. Each second sensing region T2 is arranged along the direction Y and includes a plurality of anode layers 31. Each second sensing region T2 includes, for example, one or more and 256 or less anode layers 31. As described above, the anode layers 21 and 31 are electrically separated. Therefore, the first sensing region T1 and the second sensing region T2 function as independent touch sensing regions.

Each of the first sensing region T1 and the second sensing region T2 may be one, or may be divided into, for example, two or more and 100 or less. The numbers of the first sensing region T1 and the second sensing region T2 may be the same or different from each other. At least one of the first sensing region T1 and the second sensing region T2 may be variable. For example, at least one of the first sensing region T1 and the second sensing region T2 may be changed to a number or size corresponding to the image displayed by the display unit 3.

Each of the wiring portions 4 to 7 is a portion including a plurality of routing wirings. The wiring unit 4 includes a routing wiring that connects the anode layer 21 of the organic EL element 11a and the integrated circuit 8. The wiring unit 5 includes a routing wiring that connects the anode layer 31 of the organic EL element 11b and the integrated circuit 8. The wiring unit 6 includes a routing wiring that connects the cathode layers 23 and 33 of the organic EL element 11 and the integrated circuit 8. The wiring unit 7 includes a routing wiring that connects the integrated circuit 8 and the FPC 9. Each routing wiring in the wiring portions 4 to 7 includes, for example, a molybdenum alloy layer, an aluminum alloy layer, and a molybdenum alloy layer that are laminated in order. The routing wirings in the wiring portions 4 to 7 may be formed at the same time, or may be formed at different timings. At least a part of the routing wiring may be covered with a barrier film.

The integrated circuit 8 is a drive circuit that controls light emission and non-light emission of each organic EL element 11, and is a drive circuit that processes detection of objects located in the first sensing region T1 and the second sensing region T2. The integrated circuit 8 is mounted on the main surface 2a of the substrate 2 in a region different from the display unit 3, and is connected to the anode layers 21 and 31 and the cathode layers 23 and 33. The integrated circuit 8 is, for example, an IC chip or the like.

The FPC 9 is a wiring that connects the organic EL display device 1 and an external device, and is connected to the integrated circuit 8 via the routing wiring of the wiring unit 7. The FPC 9 is formed using, for example, a flexible plastic substrate. The external device connected to the FPC 9 is, for example, a power supply and a current control circuit.

Next, an example of the driving method of the organic EL display device 1 according to the present embodiment will be described with reference to FIG. FIG. 3 is a flowchart for explaining a driving method of the organic EL display device 1.

As shown in FIG. 3, first, an image is displayed on the display unit 3 (step ST1). In step ST1, the integrated circuit 8 transmits a signal for controlling light emission and non-light emission of each organic EL element 11. In the present embodiment, signals for controlling the light emission of the organic EL layer 22 and the organic EL layer 32 are transmitted to the anode layers 21 and 31 and the cathode layers 23 and 33, respectively. As a result, each organic EL element 11 emits light or does not emit light, and an image is displayed on the display unit 3. In step ST1, the image displayed on the display unit 3 may change. That is, in step ST1, the moving image may be displayed on the display unit 3.

Next, touch sensing is performed on the display unit 3 (step ST2). In step ST2, the integrated circuit 8 detects the presence or absence of an object in contact with the surface of the substrate 2 opposite to the main surface 2a via the anode layers 21 and 31. In the present embodiment, the integrated circuit 8 detects the presence or absence of a change in the capacitance of the anode layers 21 and 31. The integrated circuit 8 performs a function according to the location of the anode layers 21 and 31 that have detected the change in capacitance.

The steps ST1 and ST2 are sequentially performed at arbitrary timings in a predetermined period (for example, 1 second). For example, when one second is divided into 60 frames, step ST1 is performed in the first 40 frames (first timing), and step ST2 is performed in the remaining 20 frames (second timing). The period of the first and second timings and the like can be arbitrarily set.

According to the organic EL display device 1 according to the present embodiment described above, the anode layer 21 also functions as a first touch electrode, and the anode layer 31 may also serve as a second touch electrode different from the first touch electrode. Function. Therefore, the touch panel function can be exhibited without attaching the substrate on which the touch panel is formed to the organic EL display device 1. Therefore, the touch panel function can be exhibited while reducing the number of parts. In addition, the anode layers 21 and 31 face each other in direction X and are separated from each other. Therefore, the sensing region in the direction X can be separated into two. As a result, the number of sensing regions can be increased as compared with the case where the anode layers 21 and 31 are not divided. Here, in the present embodiment, the anode layers 21 and 31 are located on a straight line extending along the direction X. More specifically, the central axes of the anode layers 21 and 31 along the direction X overlap each other.

In the present embodiment, the organic EL display device 1 includes an insulating film 12 that fills the gap S between the anode layers 21 and 31 in the direction X. Therefore, since the anode layers 21 and 31 can be reliably insulated, the yield of the organic EL display device 1 can be improved.

In the present embodiment, the organic EL display device 1 includes a partition wall 13 located on the insulating film 12 and separating the adjacent organic EL layers 22 and 32 in the direction X, and the width of the partition wall 13 along the direction X is the direction. It may be longer than the width W of the gap S along X. In this case, it is possible to prevent the gap S between the anode layers 21 and 31 from affecting the display of the organic EL display device 1.

In the present embodiment, the organic EL display device 1 includes an integrated circuit 8 which is a drive circuit connected to the anode layers 21 and 31 and the cathode layers 23 and 33, and the integrated circuit 8 is organic at the first timing. Signals for controlling the light emission of the EL layers 22 and 32 are transmitted to the anode layers 21 and 31 and the cathode layers 23 and 33, and come into contact with the surface of the substrate 2 opposite to the main surface 2a at the second timing. The presence or absence of an object may be detected via the anode layers 21 and 31. In this case, the light emission control of the organic EL layers 22 and 32 and the detection of the first and second sensing regions T1 and T2 can be realized by a single drive circuit. As a result, the number of parts can be further reduced. Here, the integrated circuit 8 may detect the presence or absence of a change in the capacitances of the anode layers 21 and 31 at the second timing.

The organic EL display device according to the present invention is not limited to the above-described embodiment, and various other modifications are possible. FIG. 4 is a schematic perspective view of the organic EL display device according to the modified example. The organic EL display device 1A shown in FIG. 4 includes the configuration of the organic EL display device 1 of the above embodiment and the sealing substrate 50. The sealing substrate 50 is provided so as to face the substrate 2, and is, for example, a glass substrate, a ceramics substrate, a metal substrate, a plastic substrate, or the like. The sealing substrate 50 may exhibit flexibility or may exhibit translucency. The substrate 2 and the sealing substrate 50 are sealed with, for example, an ultraviolet curable resin or the like. At this time, the space between the substrate 2 and the sealing substrate 50 may be filled with a filler containing a desiccant. Alternatively, a desiccant may be provided in the above space. Further, the integrated circuit and the like exposed from the sealing substrate 50 are covered with the protective resin 60. The protective resin 60 is, for example, various curable resins.

In the above embodiment, the order of steps ST1 and ST2 is not limited. After step ST2 is carried out, step ST1 may be carried out. Further, at least one of steps ST1 and ST2 may be performed a plurality of times in one second. For example, when one second is divided into 60 frames, step ST1 may be performed in the first 20 frames, step ST2 may be performed in the following 10 frames, and step ST1 may be performed again in the remaining 30 frames.

In the above embodiment, the main surface of the substrate has a substantially rectangular shape, but the present invention is not limited to this. The main surface of the substrate may have a polygonal shape or a substantially circular shape. Further, in the above embodiment, the width of the partition wall along the direction X is longer than, but not limited to, the width of the gap between the two anode layers facing each other in the direction X. The width of the partition wall along the direction X may be equal to or less than the width of the gap between the two anode layers.

In the above embodiment, the anode layer 21, the organic EL layer 22, and the cathode layer 23 are laminated in order from the substrate 2 side, but the present invention is not limited to this. For example, the cathode layer 23, the organic EL layer 22, and the anode layer 21 may be laminated in this order from the substrate 2 side. Therefore, the first and second electrode layers may be a cathode layer, and the third and fourth electrode layers may be an anode layer. In this case, each cathode layer also functions as a touch electrode.

1 ... Organic EL display device, 2 ... Substrate, 2a ... Main surface, 3 ... Display unit, 4 to 7 ... Wiring unit, 8 ... Integrated circuit (drive circuit), 9 ... FPC, 11, 11a, 11b ... Organic EL element , 12 ... Insulating film, 13 ... Partition, 21 ... Anode layer (first electrode layer), 22 ... Organic EL layer (first organic EL layer), 23 ... Cathode layer (third electrode layer), 31 ... Anode layer ( 2nd electrode layer), 32 ... Organic EL layer (2nd organic EL layer), 33 ... Cathode layer (4th electrode layer), S ... Gap, W ... Width.

Claims (6)

A substrate having a main surface extending along a first direction and a second direction intersecting each other,
A first electrode layer and a second electrode layer located on the substrate and extending along the first direction,
The first organic EL layer located on the first electrode layer and
The second organic EL layer located on the second electrode layer and
A third electrode layer located on the first organic EL layer and extending along the second direction,
A fourth electrode layer located on the second organic EL layer and extending along the second direction,
With
The first electrode layer and the second electrode layer face each other in the first direction and are separated from each other.
The first electrode layer also functions as a first touch electrode and
The second electrode layer is an organic EL display device that also functions as a second touch electrode different from the first touch electrode. The organic EL display device according to claim 1, wherein the first electrode layer and the second electrode layer are located on a straight line extending along the first direction. The organic EL display device according to claim 1 or 2, further comprising an insulating film that fills a gap between the first electrode layer and the second electrode layer in the first direction. Further provided with a partition wall located on the insulating film and separating the first organic EL layer and the second organic EL layer.
The organic EL display device according to claim 3, wherein the width of the partition wall along the first direction is longer than the width of the gap along the first direction. A drive circuit connected to the first electrode layer, the second electrode layer, the third electrode layer, and the fourth electrode layer is further provided.
The drive circuit
At the first timing, the signals for controlling the light emission of the first organic EL layer and the second organic EL layer are transmitted to the first electrode layer, the second electrode layer, the third electrode layer, and the above. Send to the 4th electrode layer,
Any of claims 1 to 4, wherein at the second timing, the presence or absence of an object in contact with the surface of the substrate opposite to the main surface is detected via the first electrode layer and the second electrode layer. The organic EL display device according to item 1. The organic EL display device according to claim 5, wherein at the second timing, the presence or absence of a change in the capacitance between the first electrode layer and the second electrode layer is detected.

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