JP2017129863A - Display device with built-in touch panel function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device with a built-in touch panel function capable of avoiding increase in thickness, the number of processes, and component cost and deterioration in display quality.SOLUTION: A display device 1 with a built-in touch panel function comprises an array substrate 2, a wiring layer 5, an organic light-emitting layer 9, a sealing layer 12, a sensor electrode 16a, and a circuit board 18. The wiring layer 5 is formed on the array substrate 2. The organic light-emitting layer 9 is formed on the array substrate 2. The sealing layer 12 is formed on the organic light-emitting layer 9. The sensor electrode 16a is formed on a side opposite to the array substrate 2 of the sealing layer 12, and electrically connected to the wiring layer 5. The circuit board 18 is connected to the wiring layer 5.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a display device with a built-in touch panel function.

  In general, an organic electroluminescence (EL) display device forms a display screen by a plurality of display pixels arranged in a plurality of rows and a plurality of columns.

  Each display pixel includes an organic EL element that is a self-light-emitting element and a pixel circuit that supplies a drive current to the organic EL element. A display operation of the display pixel is performed by controlling the light emission luminance of the organic EL element.

  The display device may include a touch panel function that detects a change in capacity caused by touching the display screen. When a human finger approaches the display screen, the display device having the touch panel function determines the position of the finger on the display screen based on a change in capacitance between the finger and the sensor electrode formed on the display screen. To detect.

Japanese Patent No. 5161165

  A conventional display device with a built-in touch panel function is configured by attaching a touch panel in which matrix-like electrodes are formed on an upper surface of a display device. Hereinafter, this method is referred to as an external method. In the external method, the thickness and weight of the touch panel are added to the thickness of the display device, and the thickness and weight of the entire display device may increase. In addition, in the external attachment method, the display device and the touch panel are bonded to each other, which increases the number of processes and increases the member cost. Furthermore, in the external method, since an additional glass substrate is required, the reflection of surface incident light increases, and the display quality may deteriorate.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a display device with a built-in touch panel function capable of avoiding an increase in thickness, weight, process, and member cost and a decrease in display quality.

  A display device with a built-in touch panel function according to one embodiment of the present invention includes an array substrate, a wiring layer, an organic light emitting layer, a sealing layer, a sensor electrode, and a circuit substrate. The wiring layer is formed on the array substrate. The organic light emitting layer is formed on the array substrate. The sealing layer is formed on the organic light emitting layer. The sensor electrode is formed on the opposite side of the sealing layer from the array substrate, and is electrically connected to the wiring layer. The circuit board is connected to the wiring layer.

FIG. 3 is a cross-sectional view illustrating an example of an outline of a display device according to the embodiment. The top view which shows an example of the lower surface side of the opposing board | substrate which concerns on this embodiment. The top view which shows the 1st example of the upper surface side of the opposing board | substrate which concerns on this embodiment. The top view which shows the 2nd example of the upper surface side of the opposing board | substrate which concerns on this embodiment. The perspective view which shows an example of the typical structure of the display apparatus which concerns on this embodiment. The perspective view which shows an example of the typical structure of the conventional organic electroluminescent display apparatus. FIG. 3 is a plan view illustrating an example of a pixel on a counter substrate according to the present embodiment. The top view which shows an example of a sensor electrode. The perspective view which shows an example of a typical structure of a counter substrate, an array substrate, and a flexible printed circuit board. The figure which shows an example of the relationship between the display timing of the display part of the display apparatus which concerns on this embodiment, and the touch detection timing of a touchscreen part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same or substantially the same functions and components are denoted by the same reference numerals, and will be described as necessary.

  FIG. 1 is a cross-sectional view illustrating an example of an outline of a display device 1 according to the present embodiment.

  The display device 1 is an in-cell type organic EL display device having a built-in touch panel function capable of inputting information from a screen. The display device 1 may be another display device having a built-in touch panel function and having a sealing layer, for example, a display device including an organic light emitting diode (OLED), or a liquid crystal display device. The upper side in FIG. 1 is the surface side (outside) of the display device 1, and the lower side is the back side (inside) of the display device 1.

  The display device 1 has a configuration in which the array substrate 2 and the counter substrate 3 are bonded together. In the present embodiment, the counter substrate 3 is a counter color filter (CF) substrate. In this embodiment, the array substrate 2 to the electron injection layer 10 in FIG. 1 is the display unit (organic EL driving unit) 1A, and the color layer 14 to the sensor electrode 16b is the touch panel unit 1B.

  On the array substrate 2, a wiring layer 4 and a wiring layer 5 are formed. Furthermore, although not shown, a thin film transistor (Thin Film Transistor: TFT) for driving an organic EL, a capacitor wiring, a capacitor element, various types Wiring and the like are formed. As the array substrate 2, for example, a transparent substrate such as glass is used. In the present embodiment, the wiring layer 4 is formed in the vicinity of the display area, and the wiring layer 5 is formed in the frame area. The wiring layer 5 is an OLB (Outer Lead Bonding) pad.

  A flat layer 6 is formed on the array substrate 2 on which the wiring layer 4 is formed.

  A transparent electrode 7 is formed on the flat layer 6. The transparent electrode 7 is electrically connected to the wiring layer 4 below the flat layer 6. The transparent electrode 7 is formed by patterning. Instead of the transparent electrode 7, a transparent electrode and a reflective electrode layer may be formed.

  A passivation layer 8 is formed on the flat layer 6 on which the transparent electrode 7 is formed and on the array substrate 2 between the wiring layer 4 and the wiring layer 5.

  An EL layer 9 is formed on the passivation layer 8 formed on the flat layer 6. The EL layer 9 is electrically connected to the transparent electrode 7 under the passivation layer 8. The EL layer 9 is formed by patterning.

  On the EL layer 9, an electron injection layer (EIL) 10 is formed. A part of the electron injection layer 10 is electrically connected to a part of the wiring layer 4.

  A cathode 11 is formed on the electron injection layer 10.

  On the cathode 11, on the passivation layer 8 formed on the array substrate 2 between the wiring layer 4 and the wiring layer 5, and on a part of the wiring layer 5, a sealing layer (barrier layer) is formed. ) 12 is formed. The sealing layer 12 covers and protects various elements and layers formed on the array substrate 2.

  A filling layer 13 is formed on the sealing layer 12. On the filling layer 13, the counter substrate 3 is bonded.

  For example, a transparent substrate such as glass is used as the counter substrate 3.

  Under the counter substrate 3, a color layer 14 including a red layer 14R, a green layer 14G, a blue layer 14B, and the like, and a black matrix (BM) 15 formed between the color layers 14 in a plan view. It is formed.

  Under the black matrix 15, a sensor electrode 16a for a touch panel function is formed.

  A sensor electrode 16 b is formed on the counter substrate 3.

  The sensor electrodes 16a and 16b are formed by patterning, for example. In the present embodiment, the sensor electrode 16a overlaps the black matrix 15 in the direction in which the array substrate 2 and the counter substrate 3 face each other, and therefore may be transparent or may not be transparent. The sensor electrode 16b is a transparent electrode.

  In the present embodiment, the contact 17 is formed at a predetermined position of the sealing layer 12. The contact 17 establishes conduction between the sensor electrode 16 a formed on the counter substrate 3 and the wiring layer 5 patterned on the array substrate 2. As a result, power supply and control signal transmission between the sensor electrode 16a and a flexible printed circuit board (FPC) 18 electrically connected to the contact 17 at the end on the upper surface side of the array substrate 2 are performed. Transmission / reception and transmission / reception of touch panel signals are realized.

  The contact 17 is formed, for example, by applying pressure to a predetermined position of the sealing layer 12 and connecting at least one metal pearl included in the predetermined position of the sealing layer 12 in the thickness direction. . As the metal pearl, for example, a gold plated pearl is used.

  For example, the contact 17 may be formed by removing a predetermined position of the sealing layer 12 by a technique such as etching and forming a conductor at the predetermined position where the sealing layer 12 is removed.

  For example, the contact 17 may be formed by making a hole in the sealing layer 12 and patterning a metal electrode in the hole.

  Similarly, the sensor electrode 16b and the flexible printed circuit board 19 are electrically connected at the end on the upper surface side of the counter substrate 3. Power supply, transmission / reception of control signals, and transmission / reception of touch panel signals are realized between the sensor electrode 16b and the flexible printed circuit board 19.

  In the frame region of the display device 1, a sealing material 27 is formed between the black matrix 15 and the sealing layer 12. The sealing material 27 prevents liquid and foreign matter from entering from the outside to the inside of the display device 1.

  In the present embodiment, the display device 1 has a capacitive touch panel function. Accordingly, the display device 1 captures a change in capacitance between the two sensor electrodes 16a and 16b. In the display device 1, the sensor electrode 16 a is formed on the lower surface side of the counter substrate 3, in other words, the surface side of the counter substrate 3 facing the array substrate 2, and the sensor electrode 16 b is formed on the upper surface side of the counter substrate 3. The A touch panel function is realized based on a change in capacitance between the two sensor electrodes 16a and 16b.

  In the present embodiment, the touch panel function sensor electrodes 16a and 16b are formed above the constant potential cathode 11, and the display transparent electrode 7 is formed below the cathode 11, so that the sensor electrode 16a, 16b and the transparent electrode 7 can be driven without being affected by each other.

  FIG. 2 is a plan view showing an example of the lower surface side of the counter substrate 3 according to the present embodiment.

  A color layer 14 is formed on the lower surface side of the counter substrate 3. In the present embodiment, the color layer 14 includes four color filters including a red layer 14R, a green layer 14G, a blue layer 12B, and a white layer 14W. However, the color layer 14 may include color filters of two colors, three colors, five colors or more. The red layer 14 </ b> R, the green layer 14 </ b> G, the blue layer 12 </ b> B, and the white layer 14 </ b> W are divided into regions by a black layer called a black matrix 15 in plan view.

  Under the black matrix 15, transparent electrodes 16a are formed in a lattice shape. The black matrix 15 and the sensor electrode 16a overlap in plan view.

  Since the black matrix 15 does not transmit light, when the sensor electrode 16a is formed under the black matrix 15, the aperture ratio does not decrease, and the sensor electrode 16a is formed without affecting light transmission in the opening. can do. Accordingly, the material of the sensor electrode 16a may be a transparent electrode, and when the sensor electrode 16a is formed under the black matrix 15, a metal material that does not transmit light may be used. By using a metal material as the material of the sensor electrode 16a, a low resistance material can be used as the material of the sensor electrode 16a. As a result, the display device 1 can have a large screen, and the sensor electrode 16a is hidden in the black matrix 15, so that the display performance does not deteriorate.

  On the other hand, a transparent electrode is used as a sensor electrode in the conventional method of attaching a touch panel. However, since the transmittance of the transparent electrode is not 100%, the light utilization efficiency is lowered according to the transmittance of the transparent electrode. The resistance value per unit area of the transparent electrode is, for example, 100Ω / □, which is higher than that of the metal material. Therefore, when the transparent electrode is used, the realizable screen size is limited.

By using a metal material for the driving sensor electrode of the sensor electrodes 16a and 16b, the load resistance can be reduced as compared with the case of using a transparent electrode.

By forming the grid-like sensor electrode 16a under the black matrix 15, the load capacity can be made smaller than when the strip-like sensor electrodes are widely arranged.

  A plurality of wirings connected to the sensor electrode 16a are bundled in a certain unit, and a lead wiring 20 is formed. The lead-out wiring 20 is drawn out to the lower frame region through the left and right frame regions outside the display region. The lead-out wiring 20 is electrically connected to the pad 171 in the lower frame region, and is connected to the wiring layer 5 formed on the array substrate 2 through the contact 17 connected to the pad 171.

  FIG. 3 is a plan view showing a first example of the upper surface side of the counter substrate 3 according to the present embodiment.

  The counter substrate 3 has a display area 21 and a frame area 22 surrounding the display area 21. On the upper surface side (the surface to be touched) of the counter substrate 3, a strip-shaped (or striped) sensor electrode 16b is formed of a transparent transparent electrode material. The connection portion 16 c at the end of the sensor electrode 16 b is electrically connected to the flexible printed circuit board 19.

  FIG. 4 is a plan view showing a second example of the upper surface side of the counter substrate 3 according to the present embodiment.

  On the upper surface side of the counter substrate 3 in FIG. 4, lattice-shaped sensor electrodes 16 b are formed so as to overlap with the black matrix 15 formed on the lower surface side of the counter substrate 3 not shown in FIG. 4. In the counter substrate 3 of FIG. 4, the light loss due to the sensor electrode 16b becomes zero, and it is possible to prevent the transmittance from decreasing due to the sensor electrode 16b.

  When the sensor electrode 16b is formed on the upper surface side of the black matrix 15, the sensor electrode 16b may be formed of a material that does not transmit light, such as a metal material.

  FIG. 5 is a perspective view illustrating an example of a schematic configuration of the display device 1 according to the present embodiment.

  As described above, the display device 1 is configured by bonding the array substrate 2 and the counter substrate 3 together. A flexible printed circuit board 19 for a touch panel function is provided on the upper surface side of the counter substrate 3. A flexible printed circuit board 18 for display and touch panel functions is provided on the upper surface side of the array substrate 2 facing the counter substrate 3. In the present embodiment, sensor electrodes 16a and 16b for touch panel functions are incorporated in the organic EL panel. Thereby, the touch panel function is built in the display device 1, and the display device 1 that does not increase in thickness and weight and does not sacrifice optical performance can be realized.

  FIG. 6 is a perspective view showing an example of a schematic configuration of a conventional organic EL display device.

  The conventional organic EL display device is configured by attaching a touch panel 24 to the upper surface side of the display device 23 in order to realize a touch panel function. A flexible printed circuit board 25 for a touch panel function is provided on the lower surface side of the touch panel 24. A flexible printed circuit board 26 for display is provided on the upper surface side of the array substrate 2.

  Thus, when the touch panel 24 is bonded to the upper surface side of the display device 23, the thickness and weight of the organic EL display device increase, and the number of steps for bonding increases. Moreover, since it is necessary to use a transparent electrode for the touch panel 24, the transmittance is lowered and the optical characteristics are lowered.

  FIG. 7 is a plan view showing an example of the pixel of the counter substrate 3 according to the present embodiment. FIG. 7 is a view of the pixel of the counter substrate 3 as viewed from the upper surface side, and is a plan view in which the black matrix 15 and the color layer 14 are overlaid with the sensor electrode 16a.

  FIG. 8 is a plan view showing an example of the sensor electrode 16a.

  The black matrix 15 and the sensor electrode 16a are patterned in a lattice pattern.

  One pixel P includes four sub-pixels arranged in a matrix. The four subpixels are a red subpixel PR, a green subpixel PG, a blue subpixel PB, and a white subpixel PW, respectively. Each sub-pixel PR, PG, PB, PW is divided by a grid-like black matrix 15.

  A sensor electrode 16 a is formed on the lower surface side of the black matrix 15. The line width W1 of the sensor electrode 16a is set to be equal to or smaller than the line width W2 of the black matrix 15 so that the aperture ratio of the pixel P does not decrease. Thereby, the display performance can be maintained without the sensor electrode 16a reducing the aperture ratio.

  FIG. 9 is a perspective view illustrating an example of a schematic configuration of the counter substrate 3, the array substrate 2, and the flexible printed circuit boards 18 and 19. In FIG. 9, the sealing layer 12 is represented by transparency.

  The sensor electrode 16b on the upper surface side of the counter substrate 3 is electrically connected to the flexible printed circuit board 19 for the touch panel function.

  The sensor electrode 16 b on the lower surface side of the counter substrate 3 is electrically connected to the wiring layer 5 on the upper surface side of the array substrate 2 via a contact 17 penetrating the sealing layer 12. The wiring layer 5 is electrically connected to the flexible printed circuit board 18 for display and touch panel functions.

  As described above, the contact 17 may be formed, for example, by connecting a conductor such as a metal pearl in the thickness direction, and by forming a hole in the sealing layer 12 and patterning a metal electrode in the hole. It may be formed.

  Thereby, the sensor electrode 16a on the lower surface side of the counter substrate 3 and the flexible printed circuit board 18 on the array substrate 2 are connected, and the sensor electrode 16a on the lower surface side of the counter substrate 3 and the flexible printed circuit board 18 on the array substrate 2 are connected. Signals can be transmitted and received between them.

  FIG. 10 is a diagram illustrating an example of the relationship between the display timing of the display unit 1A and the touch detection timing of the touch panel unit 1B of the display device 1 according to the present embodiment. The horizontal axis of FIG. 10 indicates time.

  As shown in FIG. 1, the cathode 11 is formed wider than the display region 21 for driving the organic EL element. The cathode 11 is fixed at a constant potential. The display unit 1 </ b> A on the lower surface side and the touch panel unit 1 </ b> B on the upper surface side of the display device 1 are electrically disconnected by the cathode 11.

  Therefore, the touch panel unit 1B is protected by the cathode 11 from noise generated in the display unit 1A, the organic EL drive circuit, and the like.

  Similarly, the display unit 1A is protected by the cathode 11 from noise generated when the sensor electrodes 16a and 16b of the touch panel unit 1B are driven.

  Therefore, by providing the cathode 11 between the display unit 1A and the touch panel unit 1B, the display unit 1A and the touch panel unit 1B can be driven at independent timings.

  In the present embodiment described above, the array substrate 2 and the counter substrate 3 are disposed so as to face each other. Sensor electrodes 16 a and 16 b are formed on both surfaces of the counter substrate 3. The sensor electrode 16 a formed on the side facing the array substrate 2 of the sensor electrodes 16 a and 16 b is connected to the contact 17, and the contact 17 is connected to the array substrate 2 via the sealing layer 12 formed on the array substrate 2. It is electrically connected to the formed wiring layer 5.

  Therefore, in the present embodiment, a touch sensor can be built in the display device 1, a change in capacitance of the sensor electrodes 16a and 16b can be detected, a good sensing function can be realized, and touch information can be generated. it can.

  In the present embodiment, since the touch panel is not bonded to the display device, an increase in manufacturing process and member cost can be suppressed.

  In the present embodiment, a touch panel function can be provided without increasing the thickness and weight of the display device 1. The thickness and weight of the display device 1 according to the present embodiment can be set to be substantially the same thickness and weight as a conventional organic EL display device.

In the present embodiment, display quality can be improved by overlapping at least one of the sensor electrodes 16 a and 16 b with the black matrix 15.

  This embodiment is presented as an example and is not intended to limit the scope of the invention. The novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Display apparatus, 1A ... Display part, 1B ... Touch panel part, 2 ... Array substrate, 3 ... Opposite substrate, 4, 5 ... Wiring layer, 6 ... Flat layer, 7 ... Transparent electrode, 8 ... Passivation layer, 9 ... EL Layer 10, electron injection layer 11, cathode, 12 sealing layer, 13 filling layer, 14 color layer, 14 R red layer, 14 G green layer, 14 B blue layer, 15 black matrix, 16 a, 16b ... sensor electrode, 17 ... contact, 18, 19 ... flexible printed circuit board, 20 ... lead-out wiring, 21 ... display area, 22 ... frame area, P ... pixel, PR ... red sub-pixel, PG ... green sub-pixel , PB ... blue sub-pixel, PW ... white sub-pixel.

Claims (5)

  An array substrate, a wiring layer formed on the array substrate, an organic light emitting layer formed on the array substrate, a sealing layer formed on the organic light emitting layer, and the array of the sealing layers A display device with a built-in touch panel function, comprising: a sensor electrode formed on the opposite side of the substrate and electrically connected to the wiring layer; and a circuit board connected to the wiring layer.   2. The display device with a built-in touch panel function according to claim 1, wherein the sensor electrode is made of a metal material and is patterned in a lattice shape.   3. The display device with a built-in touch panel function according to claim 1 or 2, wherein the circuit board is a flexible printed circuit board.   4. The display device with a built-in touch panel function according to claim 1, wherein the sensor electrode and the wiring layer are electrically connected via a contact provided in the sealing layer. A display device with a built-in touch panel function.   3. The display device with a built-in touch panel function according to claim 2, wherein the sensor electrode is provided so that one pixel surrounds each pixel.

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