Viewing Angle Controlled Touch Panel Device and Display Device

Abstract

The touch panel and the electrically controllable viewing angle device are combined and integrated so that they share some of their components. [Solution] The viewing angle control touch panel device includes one lower viewing angle control electrode on the upper surface of a lower transparent substrate, a plurality of lower touch panel electrodes on the upper surface of the lower transparent substrate, a plurality of upper touch panel electrodes on the lower surface of an upper transparent substrate, and a plurality of electrophoretic elements disposed between the lower surface of the upper transparent substrate and the upper surface of the lower transparent substrate, each containing electrophoretic particles and a dispersant. The plurality of lower touch panel electrodes are located above the lower viewing angle control electrode, and at least a portion of each lower touch panel electrode overlaps with the lower viewing angle control electrode in a plan view. Each electrophoretic element is sandwiched between one of the plurality of upper touch panel electrodes and the lower viewing angle control electrode.

Description

Technical Field

[0001] The present disclosure relates to a viewing angle control touch panel device and a display device.

Background Art

[0002] As electronic devices equipped with a display device having an input function, that is, a touch panel, smartphones and tablet terminals are widely available in the world. These are used in various scenes as tools for sharing information with many people.

[0003] There are various types of touch panels, such as a capacitive type, a resistive film type, an optical type, an ultrasonic type, and an electromagnetic induction type. Among them, the capacitive type is widely adopted in smartphones and tablet terminals. The touch panel is applied to various types of display devices, such as a liquid crystal display device and an organic EL (Electro Luminescence) display device. In recent years, an on-cell technology in which wiring of a touch panel is directly formed immediately above a sealing film of an organic EL (Electro Luminescence) element sealed with an inorganic film or an organic film has been used because of the advantage of making the display device thinner.

[0004] In addition, in public places such as parks, inside trains, and ATMs, display devices having a function of restricting the viewing angle so that the content displayed to others cannot be secretly viewed from the viewpoint of personal information protection are available. In particular, display devices that can switch between a wide viewing angle and a narrow viewing angle have attracted attention.

[0005] A plurality of methods for actively controlling a wide viewing angle and a narrow viewing angle are known. For example, one method uses a louver and PNLC (Polymer-Network Liquid Crystal). Another known method uses electrophoretic ink having a relatively short switching response time between a wide viewing angle and a narrow viewing angle. Display devices of any of these methods include two electrodes and are controlled by utilizing an electric field generated between both electrodes.

[0006] For example, organic EL display devices equipped with both touch panel functionality and viewing angle control capabilities are thinner and more multi-functional than conventional devices, making them potentially suitable for a wide range of applications. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] U.S. Patent Application Publication No. 2019 / 0102007 [Patent Document 2] U.S. Patent Application Publication No. 2019 / 0155440 [Patent Document 3] U.S. Patent Application Publication No. 2019 / 0146604 [Overview of the project] [Problems that the invention aims to solve]

[0008] Capacitive touch panels (touch sensors) detect the touch position by measuring the change in capacitance caused by finger contact on the device surface. Capacitance changes due to the capacitance generated between the finger and the electrode.

[0009] When electrodes are placed between the touch panel and the display surface, an electric field is formed between the touch panel and its electrodes, while no electric field is formed on the display surface. As a result, capacitance does not occur between the finger and the touch sensor electrodes. Therefore, the capacitive method cannot detect touch movements. In other words, if a structure with an active viewing angle control function, which controls the viewing angle (direction of transmitted light rays) using the electric field between electrodes, is formed directly on top of the touch panel, it is fundamentally difficult to achieve both functions simultaneously.

[0010] On the other hand, a configuration in which a touch panel is stacked on top of an active viewing angle control device (active louver) does not cause the above problem. However, stacking the viewing angle control device and the touch panel separately increases the overall thickness of the device. [Means for solving the problem]

[0011] One aspect of the present disclosure is a field of view control touch panel device comprising: an upper transparent substrate; a lower transparent substrate; a lower field of view control electrode on the upper surface of the lower transparent substrate; a plurality of lower touch panel electrodes on the upper surface of the lower transparent substrate; a plurality of upper touch panel electrodes on the lower surface of the upper transparent substrate; and a plurality of electrophoretic elements disposed between the lower surface of the upper transparent substrate and the upper surface of the lower transparent substrate, each containing electrophoretic particles and a dispersant, wherein the plurality of lower touch panel electrodes are located above the lower field of view control electrode, at least a portion of each of the plurality of lower touch panel electrodes overlaps with the lower field of view control electrode in a plan view, and each of the plurality of electrophoretic elements is sandwiched between one of the plurality of upper touch panel electrodes and the lower field of view control electrode.

[0012] One aspect of the present disclosure is a display device comprising an OLED display panel, a viewing angle control touch panel device disposed on the OLED display panel, and a controller, wherein the viewing angle control touch panel device comprises a plurality of upper viewing angle control electrodes, a plurality of first touch panel electrodes and a plurality of second touch panels disposed on a thin film encapsulation structure of the OLED display panel without a substrate, and a plurality of electrophoretic elements comprising electrophoretic particles and a dispersant, disposed in the stacking direction between the plurality of upper viewing angle control electrodes and a group of touch panel electrodes consisting of the plurality of first touch panel electrodes and the plurality of second touch panel electrodes. The controller includes the following: the controller controls the potential of the plurality of upper field of view control electrodes, the potential control includes alternating sensing periods and non-sensing periods, during the sensing period the potential of the plurality of first touch panel electrodes and the plurality of second touch panel electrodes is controlled to perform touch sensing, and during the non-sensing period the field of view is controlled by controlling the state of electrophoretic particles in the plurality of electrophoretic elements with respect to the electric field between the plurality of upper field of view control electrodes and the plurality of first and second touch panel electrodes, the non-sensing period is longer than the sensing period.

Advantages of the Invention

[0013] According to one aspect of the present disclosure, a touch panel and a viewing angle control device capable of electrically controlling the viewing angle can be integrally combined so that they share some of the components.

Brief Description of the Drawings

[0014] [Figure 1] A configuration example of a display device in an embodiment of this specification is schematically shown. [Figure 2] It is a cross-sectional view schematically showing the structure of a viewing angle control touch panel. [Figure 3] It is a perspective view schematically showing the structure of a viewing angle control touch panel. [Figure 4] An example of a wiring layout of a viewing angle control touch panel is shown. [Figure 5A] The cross-sectional structure at the V-V cutting line in FIG. 4 in a narrow viewing angle state is schematically shown. [Figure 5B] The cross-sectional structure at the V-V cutting line in FIG. 4 in a wide viewing angle state is schematically shown. [Figure 6A] The cross-sectional structure at the VI-VI cutting line in FIG. 4 in a narrow viewing angle state is schematically shown. [Figure 6B] The cross-sectional structure at the VI-VI cutting line in FIG. 4 in a wide viewing angle state is schematically shown. [Figure 7A] The cross-sectional structure at the V-V cutting line in FIG. 4 in a wide viewing angle state is schematically shown. [Figure 7B] The cross-sectional structure at the VI-VI cutting line in FIG. 4 in a wide viewing angle state is schematically shown. [Figure 8A] Another structural example of a viewing angle control touch panel is shown. [Figure 8B] Examples of different shapes of electrophoretic elements are shown. [Figure 9] A configuration example of a touch panel electrode group in which a plurality of continuous touch panel electrodes are bundled is shown. [Figure 10]Shows the relationship between the distance between the upper touch panel electrode and the lower touch panel electrode and the distance between the upper touch panel electrode and the lower viewing angle control electrode. [Figure 11] It is a timing chart showing an example of the time change of the potentials of the upper touch panel electrode (X electrode), the lower touch panel electrode (Y electrode), and the lower viewing angle control electrode (C electrode) in the narrow viewing angle mode. [Figure 12] Shows the details of the drive pulses for touch sensing. [Figure 13] It is a timing chart showing an example of the time change of the potentials of the upper touch panel electrode (X electrode), the lower touch panel electrode (Y electrode), and the lower viewing angle control electrode (C electrode) in the wide viewing angle mode. [Figure 14] It is a timing chart showing an example of the time change of the potentials of the upper touch panel electrode (X electrode), the lower touch panel electrode (Y electrode), and the lower viewing angle control electrode (C electrode) in the wide viewing angle mode. [Figure 15A] Shows a configuration example and operation of the receiving circuit of the X electrode included in the touch sensor IC. [Figure 15B] Shows a configuration example and operation of the receiving circuit of the X electrode included in the touch sensor IC. [Figure 15C] Shows a configuration example and operation of the receiving circuit of the X electrode included in the touch sensor IC. [Figure 16] It is a timing chart showing an example of the time change of the potentials of the upper touch panel electrode (X electrode), the lower touch panel electrode (Y electrode), and the lower viewing angle control electrode (C electrode) in the narrow viewing angle mode. [Figure 17] It is a timing chart showing an example of the time change of the potentials of the upper touch panel electrode (X electrode), the lower touch panel electrode (Y electrode), and the lower viewing angle control electrode (C electrode) in the wide viewing angle mode. [Figure 18A] Shows a manufacturing method of the display device. [Figure 18B] Shows a manufacturing method of the display device. [Figure 18C] Shows a manufacturing method of the display device. [Figure 18D]This document describes a method for manufacturing a display device. [Figure 18E] This document describes a method for manufacturing a display device. [Figure 18F] This document describes a method for manufacturing a display device. [Figure 18G] This document describes a method for manufacturing a display device. [Figure 18H] This document describes a method for manufacturing a display device. [Figure 19] An example of an electrophoretic element layout is shown. [Figure 20] A schematic example of the structure of a display device in one embodiment of this specification is shown below. [Figure 21] An example of the electrode layout for the field of view control touch panel 7 is shown. [Figure 22] This timing chart shows an example of the time variation of the potentials of the upper louver electrode, transmitting electrode (TP-Tx), and receiving electrode (TP-Rx) in narrow field mode. [Figure 23] This timing chart shows an example of the time variation of the potentials of the upper louver electrode, transmitting electrode (TP-Tx), and receiving electrode (TP-Rx) in wide-field mode. [Figure 24] This is a cross-sectional view showing other structural examples of the transmitting electrode pattern and the receiving electrode pattern. [Figure 25] Plan views of other structural examples of transmitting and receiving electrode patterns are shown. [Figure 26] A flowchart illustrating an example of a manufacturing method for a display device that includes a viewing angle control touch panel directly above a thin-film encapsulation structure is shown. [Modes for carrying out the invention]

[0015] The embodiments will be described below with reference to the attached drawings. The embodiments are merely examples for realizing the present invention and do not limit the technical scope of the present invention. Common components in each figure are denoted by the same reference numerals. For the sake of clarity, the dimensions and shapes of the illustrated objects may be exaggerated in some cases.

[0016] Capacitive touch panels (touch sensors) detect the touch position by measuring the change in capacitance caused by finger contact on the device surface. Capacitance changes due to the capacitance generated between the finger and the electrode.

[0017] When electrodes are placed between the touch panel and the display surface, an electric field is formed between the touch panel and its electrodes, while no electric field is formed on the display surface. As a result, capacitance does not occur between the finger and the touch sensor electrodes. Therefore, the capacitive method cannot detect touch movements. In other words, if a structure with an active viewing angle control function, which controls the viewing angle (direction of transmitted light rays) using the electric field between electrodes, is formed directly on top of the touch panel, it is fundamentally difficult to achieve both functions simultaneously.

[0018] On the other hand, a configuration in which a touch panel is stacked on top of an active viewing angle control device (active louver) does not cause the above problem. However, stacking the viewing angle control device and the touch panel separately increases the overall thickness of the device.

[0019] A field-of-view control touch panel according to one embodiment of this specification includes a lower field-of-view control electrode and a plurality of lower touch panel electrodes on the upper surface of a lower transparent substrate, and a plurality of upper touch panel electrodes on the lower surface of an upper transparent substrate. The upper touch panel electrodes are electrodes common to both touch sensing and field-of-view control. Each electrophoretic element is sandwiched between the upper touch panel electrodes and the lower field-of-view control electrodes. A plurality of electrophoretic elements are present between the lower surface of the upper transparent substrate and the upper surface of the lower transparent substrate. This configuration allows for the integration of the field-of-view control device and the touch panel (touch sensor), thereby reducing the thickness of the device. <Embodiment 1>

[0020] Figure 1 schematically shows an example of the configuration of a display device in one embodiment of this specification. The display device includes a display panel 5 and a viewing angle control touch panel 1 positioned in front of the display panel. The viewing angle control touch panel 1 and the display panel 5 are bonded together by an adhesive layer 31, for example, made of resin. The adhesive layer 31 between the viewing angle control touch panel 1 and the display panel 5 may be provided only in the peripheral areas of both.

[0021] The type of display panel 5 is arbitrary. Display panel 5 may be any type of display panel, such as an OLED (Organic Light Emitting Diode) display panel, a liquid crystal display panel, or a micro-LED panel. Figure 1 shows an OLED display panel as an example.

[0022] The display panel 5 includes an OLED element layer 52 on a TFT (Thin Film Transistor) substrate 51, and a thin-film encapsulation structure 53 covers the OLED element layer 52 and the TFT layer beneath it. The OLED element layer 52 includes an OLED element array consisting of a plurality of OLED elements (light-emitting elements) arranged in plane, and each OLED element is a pixel that emits light of a specific color. For example, all OLED elements may emit white light, and the OLED element layer 52 may include OLED elements that emit red, green, and blue light.

[0023] The TFT layer includes a pixel circuit array consisting of multiple pixel circuits that control the light emission of each OLED element. Each pixel circuit includes a drive TFT that controls the light emission current to the OLED element and multiple switch TFTs. Each pixel circuit operates according to a control signal and supplies the light emission current indicated by the data signal to the OLED element from the power line via the drive TFT. The signals and power to the pixel circuits are supplied, for example, from a controller (not shown in Figure 1) via an FPC (Flexible Printed Circuits) 54.

[0024] The side of the display panel 5 from which the user views the image, that is, the side from which the light rays of the image travel, is called the front or top side of the display device, and the opposite side is called the rear or bottom side. Furthermore, the direction perpendicular to the main surface of the display panel 5 and the viewing angle control touch panel 1 is called the Z-axis direction, and the two perpendicular directions within the main surface are called the X-axis direction and the Y-axis direction, respectively. The Z-axis direction is the stacking direction of the display panel 5 and the viewing angle control touch panel 1.

[0025] The viewing angle control touch panel 1 has the function of a touch sensor and also has the function of an active louver (ALV) that controls the direction of light rays passing through from the display panel 5. Functional layers for the touch sensor and light ray direction control are sandwiched between two glass substrates 111 and 112. The control signal for the viewing angle control touch panel 1 is provided, for example, via an FPC 154 from a controller (not shown in Figure 1).

[0026] The field of view control touch panel 1 can switch between a wide field of view state and a narrow field of view state to switch the range over which the image on the display panel 5 is transmitted. The state (mode) in which the range of the direction of emission from the field of view control touch panel 1 is wide is called the wide field of view state (wide field of view mode), and the state (mode) in which the range of the direction of emission is narrow is called the narrow field of view state (narrow field of view mode). Figure 1 shows the field of view control touch panel 1 in the narrow field of view state.

[0027] A circular polarizing plate 32 is placed on the front glass substrate 112 of the viewing angle control touch panel 1, and a cover glass 33 is placed on top of it. An indicator, such as a finger, touches the surface of the cover glass 33, and the viewing angle control touch panel 1 detects the touch position. The circular polarizing plate 32 reduces reflected light from the reflective electrode (e.g., anode electrode) of the OLED element. Note that the circular polarizing plate 32 and the cover glass 33 may be omitted.

[0028] Figure 2 is a schematic cross-sectional view showing the structure of the viewing angle control touch panel 1, and Figure 3 is a perspective view. Figure 2 shows the viewing angle control touch panel 1 in a wide field of view state, and Figure 3 shows the viewing angle control touch panel 1 in a narrow field of view state.

[0029] The field of view control touch panel 1 changes the dispersion state of colored electrophoretic particles (colored charged particles) 140 in the dispersion medium 141 between the upper and lower substrates 111 and 112, thereby changing the range of the direction of light emission transmitted through the region between the upper and lower substrates 111 and 112. Specifically, in the wide field of view state shown in Figure 2, the electrophoretic particles 140 are clustered near one electrode, in this case the lower field of view control electrode 126. In the narrow field of view state shown in Figure 3, the electrophoretic particles 140 are dispersed within the electrophoretic element 114.

[0030] The viewing angle control touch panel 1 includes an upper glass substrate 112 and a lower glass substrate 111. The lower surface of the lower glass substrate 111 faces the display panel 5 shown in Figure 1, and its upper surface faces the lower surface of the upper glass substrate 112. The upper glass substrate 112 and the lower glass substrate 111 are transparent substrates and may be made of a material other than glass. For example, they may be made of PET (Poly Ethylene Terephthalate), PC (Poly Carbonate), or PEN (Poly Ethylene Naphthalate). The upper glass substrate 112 and the lower glass substrate 111 are, respectively, inflexible or flexible insulators.

[0031] The field of view control touch panel 1 further includes a plurality of upper touch panel electrodes 121, a plurality of lower touch panel electrodes 123, and one lower field of view control electrode 126. The upper touch panel electrodes 121 and lower touch panel electrodes 123 may be formed from, for example, a transparent conductor such as ITO or ZnO, or a light-shielding metal such as Mo or Al. The lower field of view control electrode 126 may be formed from a transparent conductor such as ITO or ZnO. Figure 2 shows an example of a mutually capacitive field of view control touch panel 1. Other projected capacitive methods, such as self-capacitive touch detection, may also be used.

[0032] Multiple upper touch panel electrodes 121 (upper touch panel electrode pattern) are located on the lower surface of the upper glass substrate 112. Each upper touch panel electrode 121 extends in the X-axis direction on the upper glass substrate 112 and is spaced apart from one another in the Y-axis direction. Each upper touch panel electrode 121 is, for example, a single strip-shaped conductor. The upper touch panel electrodes 121 may also be called X electrodes.

[0033] The upper touch panel electrodes 121 each face the electrophoretic elements 114 and do not face the transparent region (light-transmitting region) 115 between them. The upper touch panel electrodes 121 also serve as upper viewing angle control electrodes, allowing the device to be made thinner. An insulating film 131 exists between the electrophoretic elements 114 and the upper touch panel electrodes 121. The material of the insulating film 131 is arbitrary, but for example, it is formed from silicon nitride or silicon oxide.

[0034] The signal between the upper touch panel electrode 121 and the FPC 154 is transmitted via an ACF (Anisotropic Conducting Film) 156 that is in contact with the lower surface of the upper glass substrate 112 and the upper surface of the lower glass substrate 111.

[0035] Multiple lower touch panel electrodes 123 (lower touch panel electrode pattern) are located on the upper surface of the lower glass substrate 111. The layer of the electrophoretic element 114 is located between the upper touch panel electrode pattern and the lower touch panel electrode pattern. Each lower touch panel electrode 123 extends in the Y-axis direction on the lower glass substrate 111 and is spaced apart from each other in the X-axis direction. Each lower touch panel electrode 123 is, for example, a single strip-shaped conductor. The lower touch panel electrodes 123 may also be called Y electrodes.

[0036] The upper touch panel electrodes 121 and the lower touch panel electrodes 123 are arranged in a matrix. The touch position of an indicator (e.g., a finger) is detected by the change in capacitance between the upper touch panel electrodes 121 and the lower touch panel electrodes 123.

[0037] An insulating film 132 exists between the electrophoretic element 114 and the lower touch panel electrode 123. The material of the insulating film 132 covering the lower touch panel electrode 123 is arbitrary, but for example, it is formed from silicon nitride or silicon oxide.

[0038] The lower viewing angle control electrode 126 is located on the upper surface of the lower glass substrate 111. The lower viewing angle control electrode 126 is located between the layer of the lower touch panel electrode 123 and the upper surface of the lower glass substrate 111. At least a portion of the lower touch panel electrode 123 overlaps with the lower viewing angle control electrode 126 in a plan view. An insulating film 133 exists between the lower viewing angle control electrode 126 and the lower touch panel electrode 123. The material of the insulating film 133 covering the lower viewing angle control electrode 126 is arbitrary, but for example, it is formed from silicon nitride or silicon oxide.

[0039] The lower field of view control electrode 126 is a single sheet-like electrode that faces all electrophoretic elements 114 and all upper touch panel electrodes 121. In other words, the lower field of view control electrode 126 is a common lower field of view control electrode for all electrophoretic elements 114. The state of the electrophoretic elements 114 is switched between a light-shielding state and a light-transmitting state by the voltage (electric field) between the upper touch panel electrode 121 and the lower field of view control electrode 126. In a plan view, the lower field of view control electrode 126 covers the field of view control region, that is, the region where the light-shielding state and the light-transmitting state switch. The area of ​​the lower field of view control electrode 126 is greater than or equal to the area of ​​the field of view control region.

[0040] Furthermore, multiple lower field of view control electrodes 126 may be present, each facing one or more electrophoretic elements 114 and one or more upper touch panel electrodes 121, and controlling their states. By having one lower field of view control electrode 126 be a common electrode for multiple electrophoretic elements 114, a more uniform electric field can be formed for the electrophoretic elements 114, enabling more uniform in-plane field of view control.

[0041] The viewing angle control touch panel 1 includes a viewing angle control layer between the upper glass substrate 112 and the lower glass substrate 111. The viewing angle control layer is composed of a plurality of electrophoretic elements 114 and transparent regions 115. The transparent regions 115 are light-transmitting regions. The electrophoretic elements 114 and the transparent regions 115 each extend in the X-axis direction and are arranged alternately in the Y-axis direction.

[0042] In the XY plane, the multiple electrophoretic elements 114 have a stripe pattern extending in the X-axis direction and arranged in the Y-axis direction. The transparent regions 115 between the electrophoretic elements 114 also have a stripe pattern extending in the X-axis direction and arranged in the Y-axis direction. The transparent regions 115 are formed of, for example, a translucent and photosensitive resin. The height of the transparent regions 115 is selected according to the viewing angle characteristics required for the viewing angle control touch panel, in accordance with the transmission region and the pitch of the electrophoretic elements, which will be described later. For example, it is 10 μm to 500 μm.

[0043] The electrophoretic elements 114 may be separated from each other or may be part of a continuous region. For example, each electrophoretic element may be a strip extending in the X-axis direction or the Y-axis direction within the grid-like region. In this configuration, the transparent regions may be columnar in shape, separated from each other.

[0044] Each electrophoretic element 114 contains electrophoretic particles 140 and a dispersion medium 141 (electrophoretic element material) housed in a space formed between transparent regions 115. In other words, the transparent regions 115 and the electrophoretic elements 114 have a ridge-groove relationship within the transparent resin. The electrophoretic particles 140 are colored, for example, black. The dispersion medium 141 is made of a colorless, transparent liquid material, for example. The pitch and width of the electrophoretic elements are selected according to the viewing angle characteristics required for the viewing angle control touch panel. In doing so, the pixel layout of the display is also taken into consideration when selecting the elements to suppress moiré patterns caused by the relationship between the wiring pitch of the viewing angle control touch panel and the pixel pitch of the display. For example, the width of each electrophoretic element 114 is 3 μm to 100 μm, and its pitch is 3 μm to 1000 μm.

[0045] Each electrophoretic element 114 is sandwiched between one upper touch panel electrode 121 and one lower field of view control electrode 126. In the configuration examples shown in Figures 2 and 3, different electrophoretic elements 114 are sandwiched between different upper touch panel electrodes and a common lower field of view control electrode 126.

[0046] In the examples shown in Figures 2 and 3, the electrophoretic element material, consisting of electrophoretic particles 140 and dispersion medium 141, does not come into contact with the electrodes, with insulating films 131 and 132 present between them. In other words, the insulating films 131 and 132 are exposed to and in direct contact with the electrophoretic element material. Note that these insulating films 131 and 132 may be omitted.

[0047] In other configurations, multiple consecutive electrophoretic elements may be sandwiched between one upper touch panel electrode 121 and one lower field of view control electrode. That is, multiple electrophoretic elements may face one upper touch panel electrode and one lower field of view control electrode in the Z-axis direction. Multiple electrophoretic elements are controlled by the electric field between a pair of electrodes.

[0048] The viewing angle control layer (active louver) has a large film thickness to achieve its function, which allows for a reduction in the capacitance between the touch panel electrodes 121 and 123, thereby improving touch sensor sensitivity. Therefore, even if the space between the upper touch panel electrodes 121 and the lower touch panel electrodes 123 is reduced, the impact on touch operation is minimal. This allows for the placement of a larger number of touch panel electrodes, suppressing jitter (fluctuation).

[0049] Figure 4 shows an example of the wiring layout of the viewing angle control touch panel 1. The potentials of the upper touch panel electrode 121, the lower touch panel electrode 123, and the lower viewing angle control electrode 126 are controlled by the touch sensor IC 128, which is the controller. Furthermore, the touch sensor IC 128 measures the change in capacitance between the upper touch panel electrode 121 and the lower touch panel electrode 123 and detects the touch position of the indicator based on the result. The touch sensor IC 128 may be electrically connected to these electrodes 121, 123, and 126, for example, via peripheral wiring on the FPC 154 and the lower glass substrate 111 and upper glass substrate 112.

[0050] The upper touch panel electrodes 121 are X electrodes, each extending in the X-axis direction and arranged in the Y-axis direction. The width and spacing of the upper touch panel electrodes 121 may be constant or different. The lower touch panel electrodes 123 are Y electrodes, each extending in the Y-axis direction and arranged in the X-axis direction. The width and spacing of the lower touch panel electrodes 123 may be constant or different. The upper touch panel electrodes 121 may have any shape and arrangement as long as they are appropriate for touch detection and viewing angle control. Similarly, the lower touch panel electrodes 123 may have any shape and arrangement as long as they are appropriate for touch detection.

[0051] The lower field of view control electrode 126 is sheet-shaped and, in a plan view, overlaps with the upper touch panel electrode 121 and the lower touch panel electrode 123. The upper touch panel electrode 121 is also the upper field of view control electrode. The state of the electrophoretic element 114 is controlled by the electric field between each upper touch panel electrode 121 and the lower field of view control electrode 126. In the example shown in Figure 4, all the lower field of view control electrodes 126 paired with the upper touch panel electrodes 121 are common, but multiple groups of upper touch panel electrodes 121 and separated lower field of view control electrodes 126 may each form a pair.

[0052] Figures 5A and 5B schematically show the cross-sectional structure at the VV cutting line in Figure 4. Figures 6A and 6B schematically show the cross-sectional structure at the VI-VI cutting line in Figure 4. Figures 5A and 6A show the narrow field of view, while Figures 5B and 6B show the wide field of view.

[0053] In the narrow field of view shown in Figures 5A and 6A, the electrophoretic particles 140 in each electrophoretic element 114 are dispersed in the dispersion medium 141. The dispersed electrophoretic particles 140 absorb the light from the display panel 5, thereby shielding the electrophoretic element 114 from the light from the display panel 5. As a result, only light rays within a narrow emission angle range in the Y-axis direction pass through the field of view control touch panel 1.

[0054] In the narrow field of view state, the upper touch panel electrode 121 and the lower field of view control electrode 126, which sandwich each electrophoretic element 114, are maintained at the same potential. As a result, the electrophoretic particles 140 are maintained in a dispersed state within the dispersion medium 141. Details of the potential control of the lower touch panel electrode 123 and the lower field of view control electrode 126 will be described later.

[0055] Figures 5B and 6B show the wide-field-of-view control touch panel 1. The wide-field-of-view state is achieved by accumulating the electrophoretic particles 140 near one of the electrodes flanking the electrophoretic element 114, for example, near the lower field-of-view control electrode 126. Most of the area of ​​the electrophoretic element 114 is composed only of the transparent dispersion medium 141, and the electrophoretic element 114 is in a transparent state. As a result, light rays within a wide emission angle range in the Y-axis direction pass through the field-of-view control touch panel 1.

[0056] In the wide-field state, the relative potential of the lower field of view control electrode 126 with respect to the upper touch panel electrode 121 has a polarity opposite to that of the electrophoretic particles 140 (potential difference V). As a result, the electrophoretic particles 140 gather near the lower field of view control electrode 126. In the examples in Figures 5B and 6B, the electrophoretic particles 140 are negatively charged.

[0057] For example, if the electrophoretic particle 140 has a negative charge (-), a predetermined potential is applied to the lower field of view control electrode 126 and the upper touch panel electrode 121 so that the lower field of view control electrode 126 becomes the positive electrode. If the electrophoretic particle 140 has a positive charge (+), a predetermined potential is applied to the lower field of view control electrode 126 and the upper touch panel electrode 121 so that the lower field of view control electrode 126 becomes the negative electrode. The potential difference V can be, for example, around 10V to 30V.

[0058] Figures 7A and 7B show examples of a wide-field state in which the electrophoretic particles 140 gather near the upper touch panel electrode 121. Figure 7A schematically shows the cross-sectional structure at the VV section in Figure 4, and Figure 7B schematically shows the cross-sectional structure at the VI-VI section in Figure 4. The electrophoretic particles 140 are negatively charged. A predetermined potential is applied to the lower field of view control electrode 126 and the upper touch panel electrode 121 so that the lower field of view control electrode 126 becomes the negative electrode.

[0059] In the following explanation, it is assumed that the electrophoretic particle 140 has a negative charge. If the electrophoretic particle 140 has a positive charge, it can be controlled similarly by reversing the polarity of the lower field of view control electrode 126.

[0060] The sheet resistances of insulating films 131, 132, and 133 can affect touch sensing and viewing angle control. According to the inventors' research, more appropriate touch sensing and viewing angle control could be achieved when these sheet resistances were in the range of 5E6Ω / □ to 5E8Ω / □. Touch sensing malfunctions were more likely to occur when the sheet resistance was 5E5Ω / □ or less. On the other hand, when the sheet resistance was 5E12Ω / □ or more, a long time was required to switch the viewing angle. The thickness of the insulating film should be approximately 10-100 nm.

[0061] The insulating films 131, 132, and 133 covering the touch panel electrodes 121 and 123 and the lower viewing angle control electrode 126 do not have high insulating properties, and a certain degree of leakage current (soft leakage current) is generated in a high electric field. Because the insulating films prevent direct contact between the upper touch panel electrode 121 and the lower viewing angle control electrode 126 and the electrophoretic particles 140, adhesion of the electrophoretic particles 140 to the electrodes can be avoided.

[0062] Because the insulating properties are not high, the electrophoretic particles 140 can move even without applying a high voltage between the upper touch panel electrode 121 and the lower viewing angle control electrode 126, thus achieving high reliability while maintaining the fast response of the active louver. In addition, the insulating film 133 on the lower viewing angle control electrode 126 prevents the electric field between the touch panel electrodes 121 and 123 from being affected by the potential of the lower viewing angle control electrode 126, thus maintaining the sensitivity of touch sensing.

[0063] Figure 8A shows another example of the structure of the viewing angle control touch panel 1. In the example structure shown in Figure 8A, the width of the upper touch panel electrode 121 is wider than the width of the electrophoretic element 114 (light-shielding portion).

[0064] Figure 8B shows examples of different shapes of the electrophoretic element 114. The width of the region 145 where the electrophoretic particles 140 gather may be narrower than the width of other parts. In the example in Figure 8B, the width of the region at the lower field of view control electrode 126 side is narrower than the width of the region above it. When the electrophoretic particles 140 gather towards the upper touch panel electrode 121 side, the width of that region is narrower than the width of the lower region. This makes it possible to achieve a higher transmittance of the field of view control touch panel when in narrow field of view mode.

[0065] Figure 9 shows an example of a touch panel electrode group configuration, where multiple consecutive touch panel electrodes are bundled together. The dimensions and spacing of the electrophoretic elements 114 are designed from the perspective of the viewing angle characteristics required by the active louver. Generally, the dimensions are about 3 to 100 μm. On the other hand, the electrode spacing required for touch detection is about 2 to 5 mm. The number of electrodes required differs for each function. In other words, the number of electrodes in the active louver > the number of electrodes in the touch panel.

[0066] In one embodiment of this specification, the upper touch panel electrode 121 is shared between the touch sensor and the active louver. Therefore, a group of consecutive upper touch panel electrodes 121 is bundled together to form an upper touch panel electrode group, corresponding to the number of electrodes required for the touch sensor, and connected to a single connection terminal 127. The same potential is supplied to the upper touch panel electrode group, and one signal from the upper touch panel electrode group is transmitted to the touch sensor IC 128.

[0067] In the configuration example shown in Figure 9, multiple consecutive lower touch panel electrodes 123 are bundled together to form a lower touch panel electrode group, which is connected to a single connection terminal 129. The same potential is supplied to the lower touch panel electrode group, and one signal from the lower touch panel electrode group is transmitted to the touch sensor IC 128. Note that the lower touch panel electrode group may be replaced with a single strip-shaped lower touch panel electrode.

[0068] The control of the viewing angle control touch panel 1 will be described below. As mentioned above, the viewing angle control touch panel 1 has a viewing angle control function in addition to the touch panel function. Figure 10 shows the relationship between the distance 1 between the upper touch panel electrode 121 and the lower touch panel electrode 123 and the distance 2 between the upper touch panel electrode 121 and the lower viewing angle control electrode 126.

[0069] In this structure, the spacing 1 between the upper touch panel electrode 121 and the lower touch panel electrode 123 and the spacing 2 between the upper touch panel electrode 121 and the lower viewing angle control electrode 126 are of different sizes. Specifically, spacing 2 is larger than spacing 1.

[0070] If the touch sensing period (the period during which voltage is applied to the touch panel electrodes 121 and 123) is long, the electric fields of the touch panel electrodes 121 and 123 will be different from those between the upper touch panel electrode 121 and the lower field of view control electrode 126. This difference in the movement of the electrophoretic particles 140 may result in a difference between the area on the lower touch panel electrode 123 and the area on the lower field of view control electrode 126. This difference in the movement of the electrophoretic particles 140 may be visible as unevenness.

[0071] One embodiment of this specification includes a sensing period for touch detection and a non-sensing period within a single frame period. During the sensing period, the touch sensor IC 128 provides signals for touch detection to the upper touch panel electrode 121, the lower touch panel electrode 123, and the lower viewing angle control electrode 126. During the non-sensing period, the touch sensor IC 128 provides signals for viewing angle control to the upper touch panel electrode 121, the lower touch panel electrode 123, and the lower viewing angle control electrode 126.

[0072] One embodiment of this specification sets a non-sensing period longer than the sensing period. This makes it possible to suppress the influence of the electric field between the touch panel electrodes on the electrophoretic particles 140 (visual occurrence of unevenness) during touch sensing.

[0073] Here, we will explain capacitive touch sensors. There are two types of capacitive sensors: self-capacitance detection and mutual-capacitance detection. A self-capacitance detection touch sensor has multiple X electrodes and multiple Y electrodes. The X and Y electrodes are arranged in a matrix, and the X and Y electrodes are separated by an insulator. The self-capacitance detection method drives the X and Y electrodes independently to detect changes in the capacitance value of each electrode. When an object approaches an electrode, the capacitance of that electrode increases. The self-capacitance method detects the position of the object by detecting the X and Y electrodes whose capacitance has increased.

[0074] A mutual capacitance touch panel has a transmitting electrode (e.g., Y electrode) as a driving electrode and a receiving electrode (e.g., X electrode) as a detection electrode. The driving electrode and detection electrode are arranged in a matrix, and are separated by an insulator. Capacitance (intersection capacitance) is formed at each intersection of the driving electrode and detection electrode. If an indicator is present near the intersection capacitance, a portion of the electric field at the intersection moves to the indicator. As a result, the intersection capacitance decreases. The mutual capacitance method detects the position of the indicator by detecting at which intersection and to what extent the change in mutual capacitance occurred. The mutual capacitance method will be explained below as an example.

[0075] Figure 11 is a timing chart showing an example of the time evolution of the potentials of the upper touch panel electrode 121 (X electrode), the lower touch panel electrode 123 (Y electrode), and the lower field of view control electrode 126 (C electrode) in narrow field of view mode. In the example in Figure 11, there are N Y electrodes (where N is a natural number).

[0076] The upper touch panel electrode 121 is the X electrode, which is the receiving electrode (TP-Rx) of the touch sensor and also the control electrode (ALV) of the viewing angle control device. The lower touch panel electrode 123 is the Y electrode, which is the transmitting electrode (TP-Tx) of the touch sensor. The lower viewing angle control electrode 126 is the C electrode, which is the control electrode (ALV (Active Louver)) of the viewing angle control device. Note that the upper touch panel electrode 121 may be the transmitting electrode and the lower touch panel electrode 123 may be the receiving electrode.

[0077] In the example shown in Figure 11, the frame frequency is assumed to be 60 fps. One frame duration is divided into a sensing period and a non-sensing period (ALV operation period). In the example shown in Figure 11, the non-sensing period follows the sensing period. This order can also be reversed. The sensing period is 2.6 ms, and the non-sensing period is 14 ms. The sensing period and non-sensing period alternate across consecutive frames.

[0078] The Y electrode is divided into multiple Y electrode groups, and each Y electrode group consists of bundled Y electrodes. All Y electrodes in each Y electrode group are connected to the same connector. Here, we assume that the number of Y electrodes constituting all Y electrode groups is the same (for example, 100). Similarly, the X electrode is divided into multiple X electrode groups, and each X electrode group consists of bundled X electrodes.

[0079] During the sensing period, the touch sensor IC128 applies a constant potential, in this case 0V, to all X electrodes. Note that 0V may be the system ground potential. Furthermore, the touch sensor IC128 sequentially selects the Y electrode group and applies a drive pulse 311 to each. The potential of the drive pulse is +5V. The potential of the unselected Y electrode, i.e., the Y electrode that is not being applied a drive pulse, is 0V. The same drive pulse 311 is applied to the Y electrodes of the same Y electrode group. The touch sensor IC128 applies the same potential, in this case 0V, to the lower field of view control electrode 126 (C electrode) as to the X electrodes.

[0080] During the non-sensing period, the touch sensor IC 128 applies a constant potential, in this case 0V, to all X electrodes. Furthermore, the touch sensor IC 128 applies 0V to all Y electrode groups (Y electrodes). Since the supply of drive pulses to the Y electrodes during the sensing period has ended, all Y electrodes are maintained at 0V during the transition from the sensing period to the non-sensing period. The touch sensor IC 128 applies the same potential, in this case 0V, to the lower field of view control electrode 126 (C electrode) as to the X electrodes. Throughout the sensing and non-sensing periods, the lower field of view control electrode 126 (C electrode) is maintained at 0V.

[0081] Throughout the entire period, the same potential is applied to the X electrode, which is the upper touch panel electrode 121, and the C electrode, which is the lower viewing angle control electrode 126. As a result, the electrophoretic particles 140 are dispersed within the electrophoretic element 114, and light from the display panel 5 is blocked. In other words, the viewing angle control touch panel 1 is in a narrow field of view state.

[0082] Figure 12 shows details of the drive pulse 311 for touch sensing. The drive pulse 311 is a burst signal consisting of multiple consecutive pulses. In the example shown in Figure 12, the duration of the burst signal is 80-150 μs, and its frequency is 150-200 kHz. As mentioned above, the sensing period is 2.6 ms. Note that the duration and frequency of the burst signal are arbitrary.

[0083] Figure 13 is a timing chart showing an example of the time evolution of the potentials of the upper touch panel electrode 121 (X electrode), the lower touch panel electrode 123 (Y electrode), and the lower field of view control electrode 126 (C electrode) in wide field of view mode. Compared to the timing chart explained with reference to Figure 11, the potential evolution of the X electrode (upper touch panel electrode 121) is different. Specifically, the potential of the X electrode during the non-sensing period is -20V. The potential of the X electrode during the sensing period is 0V, which is the same as in the narrow field of view state, and the time evolution of the potentials (signals) of the other electrodes is also the same as in the narrow field of view state.

[0084] During the non-sensing period, -20V is applied to the X electrode, which is the upper touch panel electrode 121, and 0V is applied to the C electrode, which is the lower field of view control electrode 126. As a result, the negatively charged electrophoretic particles 140 gather in the area closer to the lower field of view control electrode 126. In other words, the field of view control touch panel 1 is in a wide field of view state.

[0085] Figure 14 is a timing chart showing an example of the time evolution of the potentials of the upper touch panel electrode 121 (X electrode), the lower touch panel electrode 123 (Y electrode), and the lower field of view control electrode 126 (C electrode) in wide field of view mode. Compared to the timing chart explained with reference to Figure 13, the potential of the X electrode (upper touch panel electrode 121) during the sensing period is different. Specifically, the same -20V as during the non-sensing period is applied to the X electrode. From the viewpoint of touch sensing, a potential of 0V is preferable to -20V for the X electrode during the sensing period, but in the example shown in Figure 14, the X electrode can be maintained at a constant potential.

[0086] In the example described with reference to Figures 11 to 14, the potential of the lower viewing angle control electrode 126 is constant. This facilitates the control of the active louvers.

[0087] In the control described with reference to Figures 11 to 14, one frame period is divided into a sensing period and a non-sensing period, with the non-sensing period being longer than the sensing period. Furthermore, the non-sensing period per frame is 84%, and the sensing period is 16%. This makes it possible to suppress the influence of the electric field between the touch panel electrodes on the electrophoretic particles 140 (visual occurrence of unevenness) during touch sensing.

[0088] Note that the duty cycle values ​​for the non-sensing period and the sensing period are not limited to the examples above.

[0089] The behavior of electrophoretic particles is explained below. Given an applied electric field E and application time t, the distance s traveled by the electrophoretic particle is expressed by the following equation. s=v·t(v: speed) v=μ·E (μ: mobility)

[0090] The mobility of spherical electrophoretic particles can be described as follows: μ = q / (6π·η·α) q: Charge amount η: viscosity of the solvent α: Particle size

[0091] From the above, the distance s that the electrophoretic particles travel can be expressed as follows. s = v·t = qEt / (6πηα)

[0092] In other words, for electrophoretic particles with the same charge, the stronger the electric field or the longer the voltage application time, the greater the amount of electrophoretic particle movement. As described above, by setting the non-sensing period to be longer than the sensing period in the alternating sensing and non-sensing periods, the amount of electrophoretic particle movement is increased, suppressing the occurrence of unevenness.

[0093] Electrophoretic particles 140 have difficulty keeping up with short-term voltage changes, and also move less easily when the electric field strength is weak. The electrophoretic particles 140 gradually move during the voltage application period between the upper touch panel electrode 121 (X electrode) and the lower field of view control electrode (C electrode) 126. Over multiple frame periods, the electrophoretic particles change from a dispersed state to an aggregated state or from an aggregated state to a dispersed state. Considering this property, a driving method with a short touch sensing period can achieve more appropriate field of view switching without affecting touch sensing.

[0094] The sensing period and non-sensing period do not necessarily have to be constant. Having constant sensing and non-sensing periods facilitates touch sensing and field of view control.

[0095] Figures 15A to 15C show examples of the configuration and operation of the receiving circuit for the X electrode (upper touch panel electrode 121) included in the touch sensor IC 128. Figures 15A to 15C correspond to the operation described with reference to Figures 11 and 13. Figure 15A shows the state during sensing. Figure 15B shows the state when not sensing in narrow field of view mode. Figure 15C shows the state when not sensing in wide field of view mode.

[0096] Next, an example of self-capacitance type touch sensing will be described. Figure 16 is a timing chart showing an example of the time change of the potential of the upper touch panel electrode 121 (X electrode), the lower touch panel electrode 123 (Y electrode), and the lower field of view angle control electrode 126 (C electrode) in narrow field of view mode. The X electrodes are bundled in groups of 100, and the Y electrodes are bundled in groups of 100.

[0097] Similar to the timing chart in the narrow field of view mode of the mutual capacitance method shown in Figure 11, the touch sensor IC 128 divides one frame period into a sensing period and a non-sensing period. The non-sensing period is longer than the sensing period.

[0098] The sensing period includes a preparation period of a predetermined length from its start. During the preparation period provided within the sensing period, the touch sensor IC128 sets all X and Y electrodes to a high-impedance state. This avoids crosstalk and residual signals from the previous scan.

[0099] Next, the touch sensor IC128 sequentially selects either the X electrode group or the Y electrode group and applies a sensing pulse voltage 321 (+5V in Figure 16) to measure the capacitance. The sensing pulse voltage 321 is, for example, a burst signal. At this time, the touch sensor IC128 maintains the unselected X and Y electrodes in a high impedance state. By making the unselected X and Y electrodes high impedance, unnecessary current flowing through parasitic capacitance can be reduced. During the sensing period, the touch sensor IC128 applies 0V (or system ground) to the C electrode.

[0100] During the non-sensing period, the touch sensor IC128 provides 0V (or system ground) to all X, Y, and C electrodes. Since the X and C electrodes are at the same potential, the electrophoretic particles 140 are in a dispersed state. In other words, the field of view control touch panel 1 is in a narrow field of view state.

[0101] Figure 17 is a timing chart showing an example of the time evolution of the potentials of the upper touch panel electrode 121 (X electrode), the lower touch panel electrode 123 (Y electrode), and the lower field of view control electrode 126 (C electrode) in wide field mode. Compared to the timing chart in narrow field mode shown in Figure 16, the potential of the X electrode during the non-sensing period is different. Specifically, during the non-sensing period, the potential of the X electrode is +20V. Since the potential of the lower field of view control electrode 126 (C electrode) is constant at 0V, a force is applied to the negatively charged electrophoretic particles 140 to aggregate toward the X electrode during the non-sensing period.

[0102] Furthermore, the explanation of the relationship between the sensing period, non-sensing period, and 1-frame period described for the mutual-capacitance method is also applicable to the self-capacitance method.

[0103] As described above, one embodiment of this specification shares a portion of the electrodes (upper touch panel electrode 121) of the field of view control device and the touch sensor. This makes it possible to reduce the thickness of the field of view control device (active louver). Furthermore, since the behavior of the electrophoretic particles 140 is controlled by the lower field of view control electrode 126 (C electrode), which has a large surface area, a more uniform electric field can be formed, enabling uniform in-plane operation of the field of view control device.

[0104] One embodiment of this specification employs a time-sequential system with a short touch-sensing period to reduce the influence of the electric field on the electrophoretic particles 140 during the touch-sensing period, and suppresses the occurrence of unevenness in the electrophoretic particles 140 when switching the field of view characteristics by applying an electric field for field of view control during a sufficiently long non-sensing period. In one embodiment of this specification, when switching between wide and narrow fields of view, only the upper touch panel electrode 121 has its potential changed for field of view control. This simplifies the control.

[0105] The following describes an example of a manufacturing method for a display device including a viewing angle control touch panel 1. The following manufacturing method is just one example, and the display device may be manufactured by any other method.

[0106] Referring to Figure 18A, the manufacturing method involves forming a metal film 301 on the upper glass substrate 112, and then forming an insulating film 302 on top of that.

[0107] Next, referring to Figure 18B, the manufacturing method involves simultaneously patterning the metal film 301 and the insulating film 302 by resist coating, exposure, development, and etching. This forms the patterns for the upper touch panel electrode 121 and the insulating film 131 on the upper glass substrate 112.

[0108] Next, referring to Figure 18C, the manufacturing method involves applying a photosensitive permanent film 303 to the upper glass substrate 112 so as to cover the upper touch panel electrode 121 and the insulating film 131, and then performing pre-baking.

[0109] Next, referring to Figure 18D, the manufacturing method involves exposing and developing the photosensitive permanent film 303 using the upper touch panel electrode 121 as a mask to form a transparent region (light-transmitting region) 115. This step completes the upper substrate. Note that the transparent region 115 may also be formed using nanoimprint technology instead of photolithography technology.

[0110] Next, referring to Figure 18E, the lower viewing angle control electrode 126, insulating film 133, lower touch panel electrode 123, and insulating film 132 are formed on the lower glass substrate 111. This completes the lower substrate.

[0111] This step involves, for example, forming a metal film on the lower viewing angle control electrode 126 and an insulating film thereon, and then forming the lower viewing angle control electrode 126 and the insulating film 133 by resist coating, exposure, development, and etching. Furthermore, this step involves forming a metal film on the lower touch panel electrode 123 and an insulating film thereon, and then forming the pattern of the lower touch panel electrode 123 and the insulating film 132 by resist coating, exposure, development, and etching.

[0112] Next, referring to Figure 18F, the manufacturing method involves heating and pressing the upper and lower substrates together to form the viewing angle control touch panel 1. During this process, the terminals of the upper substrate and the terminals of the lower substrate are electrically connected using an anisotropic conductive film (ACF) or the like. Next, referring to Figure 18G, the manufacturing method involves injecting electrophoretic element material into the space between the transparent regions 115. Next, referring to Figure 18H, the viewing angle control touch panel 1 and the display panel 5 are bonded together.

[0113] Next, an example of the layout of the electrophoretic elements 114 will be described. Figure 19 shows an example of the layout of the electrophoretic elements 114. In this layout, the electrophoretic elements 114 are columnar and arranged in a staggered pattern. More specifically, each row of electrophoretic elements, consisting of electrophoretic elements 114 arranged in the X-axis direction and separated from each other, is positioned below the upper touch panel electrode. Each electrophoretic element 114 is controlled by the upper touch panel electrode 121 and the lower field of view control electrode 126.

[0114] In each row, the electrophoretic elements 114 are arranged at equal intervals. The positions of the electrophoretic elements 114 in adjacent rows are offset in the Y-axis direction. That is, in the Y-axis direction, each electrophoretic element 114 is located between adjacent electrophoretic elements 114 in two adjacent rows. This layout allows for control of the field of view in the X-axis and Y-axis directions. <Embodiment 2>

[0115] Figure 20 schematically shows an example of the structure of a display device in one embodiment of this specification. The differences from the example structure shown in Figure 1 will be mainly explained. Unless otherwise specified, the materials and sizes of each component may be the same as those of similar components described with reference to Figure 1 and other drawings. The display device includes a display panel 5 and a viewing angle control touch panel 7 located in front of the display panel. The configuration of the display panel 5 is the same as that of the display panel 5 shown in Figure 1.

[0116] The viewing angle control touch panel 7 is in direct contact with and positioned on the thin-film encapsulation structure 53. The thin-film encapsulation structure 53 is composed of multiple layers and is an encapsulation layer that protects the OLED element from oxygen and moisture. The thin-film encapsulation structure 53 may include alternately arranged inorganic material layers and organic material layers, or it may consist only of inorganic material layers or organic material layers. The inorganic material may be, for example, silicon nitride (SiNx) or aluminum oxide (Al2O3), and the organic material may be, for example, acrylic resin. The thin-film encapsulation structure 53 may consist, for example, of two silicon nitride layers and an organic material layer between them, and may further include additional inorganic material layers and / or organic material layers.

[0117] The viewing angle control touch panel 7 includes, from the bottom layer, a transmitting electrode (TP-Tx) 723, an insulating film 731, a receiving electrode (TP-Rx) 726, an insulating film 732, an electrophoretic element 714, an upper louver electrode 721, and a polyimide substrate 712. The upper louver electrode 721, the transmitting electrode 723, and the receiving electrode 726 are electrically isolated. The upper louver electrode 721 is the upper viewing angle control electrode. The positions of the transmitting electrode 723 and the receiving electrode 726 may be swapped.

[0118] The viewing angle control touch panel 7 is positioned directly on the thin-film encapsulation structure 53. In other words, the lower glass substrate 111 in the structural example shown in Figure 1 is omitted. Furthermore, compared to the structural example shown in Figure 1, the cover glass 33 is omitted, and a flexible polyimide substrate 712 is placed in place of the upper glass substrate 112.

[0119] The polyimide substrate 712 and the circular polarizer 62 are firmly bonded together by an adhesion layer 63, for example, made of resin, between them. An example of a mutually capacitive touch panel structure is described below, but a self-capacitive touch panel structure may also be employed.

[0120] Multiple electrophoretic elements 714 are arranged between the thin film encapsulation structure 53 and the polyimide substrate 712. Multiple upper louver electrodes 721 are formed between the lower surface of the polyimide substrate 712 and the electrophoretic elements 714, and each upper louver electrode 721 faces the electrophoretic elements 714 to control the dispersion state of the electrophoretic particles. An insulating film 731 is present between the electrophoretic elements 714 and the upper touch panel electrodes 721.

[0121] The state of the electrophoretic particles in the electrophoretic element 714 is controlled by the electric field between the upper louver electrode 721 and the touch panel receiving electrode (TP-Rx) 726. The receiving electrode 726 also serves as the lower viewing angle control electrode.

[0122] The field of view control touch panel 7 has a different electrode structure from the field of view control touch panel 1 shown in Figure 1. The field of view control touch panel 7 includes a plurality of transmitting electrodes 723 directly formed on the thin film sealing structure 53, an insulating film 731 covering the transmitting electrodes 723, a plurality of receiving electrodes 726 formed on the insulating film 731, and an insulating film 732 covering the insulating film 731 and the receiving electrodes 726. The transmitting electrodes 723 and the receiving electrodes 726 are electrodes of a mutual capacitive touch panel. An additional insulating film may be present between the transmitting electrodes 723 and the thin film sealing structure 53.

[0123] Figure 21 shows an example of the electrode layout of the viewing angle control touch panel 7. Figure 21 is merely one example of a layout, and other layouts may be used. The potential of the upper louver electrode 721 is controlled by the louver control unit 728 included in the controller. The potentials of the transmitting electrode 723 and the receiving electrode 726 are controlled by a touch panel control unit (not shown) included in the controller. The touch panel control unit measures the change in capacitance between these electrodes and detects the touch position of the indicator based on the result.

[0124] In the configuration example shown in Figure 21, the upper louver electrodes 721 are X electrodes, each extending in the X-axis direction and arranged in the Y-axis direction. The width and spacing of the upper louver electrodes 721 may be constant or different. The upper louver electrodes 721 may have, for example, a rectangular strip shape, but their shape is not limited.

[0125] The transmitting electrodes 723 are X electrodes, each extending in the X-axis direction and arranged in the Y-axis direction. The spacing between the transmitting electrodes 723 may be constant or varied. As shown in Figure 21, the transmitting electrodes 723 may have a shape in which a wide section having a rhombus (rectangle) shape is connected by a narrower, strip-shaped connecting section, or they may have other shapes such as rectangular strips.

[0126] The receiving electrodes 726 are Y electrodes, each extending in the Y-axis direction and arranged in the X-axis direction. The spacing between the receiving electrodes 726 may be constant or varied. As shown in Figure 21, the receiving electrodes 726 may have a shape in which a wide section having a rhombus (rectangle) shape is connected by a narrower, strip-shaped connecting section, or they may have other shapes such as rectangular strips. In the configuration example in Figure 21, the connecting sections of the transmitting electrode 723 and the receiving electrode 726 overlap in the stacking direction, while the wide sections do not overlap and are separated in the stacking direction.

[0127] Figure 22 is a timing chart showing an example of the time evolution of the potentials of the upper louver electrode 721, the transmitting electrode 723 (TP-Tx), and the receiving electrode 726 (TP-Rx) in narrow field mode. Compared with the timing chart shown in Figure 11, the time evolution of the potential of the upper louver electrode 721 is the same as the time evolution of the potential of the X electrode (TP-Rx, ALV). The time evolution of the potential of the transmitting electrode 723 (TP-Tx) is the same as the time evolution of the potential of the Y electrode (TP-Tx). The time evolution of the potential of the receiving electrode 726 (TP-Rx) is the same as the time evolution of the potential of the C electrode. As explained with reference to Figures 11 and 12, the drive pulse for touch sensing at the transmitting electrode 723 is a burst signal.

[0128] Figure 23 is a timing chart showing an example of the time variation of the potentials of the upper louver electrode 721, the transmitting electrode 723 (TP-Tx), and the receiving electrode 726 (TP-Rx) in wide-field mode. Compared to the timing chart explained with reference to Figure 22, the potential variation of the upper louver electrode 721 is different. The potential of the upper louver electrode 721 during the non-sensing period is -20V. The potential of the upper louver electrode 721 during the sensing period is 0V, which is the same as in the narrow-field state, and the time variation of the potentials (signals) of the other electrodes is also the same as in the narrow-field state.

[0129] During the non-sensing period, -20V is applied to the upper louver electrode 721, and 0V is applied to the receiving electrode 726 (TP-Rx) and transmitting electrode 723 (TP-Tx), which can function as lower field of view control electrodes. As a result, negatively charged electrophoretic particles gather in the region closer to the receiving electrode 726 (TP-Rx). In other words, the field of view control touch panel 7 is in a wide field of view state. Furthermore, by applying a positive potential, for example +20V, to the upper louver electrode 721 during the non-sensing period, negatively charged electrophoretic particles can be gathered in the region closer to the upper louver electrode 721. Figures 24 and 25 show other structural examples of the transmitting electrode pattern and receiving electrode pattern. Figure 24 is a cross-sectional view, and Figure 25 is a plan view. The differences from the structural examples described with reference to Figures 20 and 21 will be mainly explained. The viewing angle control touch panel 71 includes a plurality of transmitting electrodes 743 and a plurality of receiving electrodes 746.

[0130] The transmitting electrode 743 and the receiving electrode 746 are formed directly on the thin film sealing structure 53. More specifically, the entire area of ​​the transmitting electrode 743 and the rhombus-shaped wide portion of the receiving electrode 746 are formed directly on the thin film sealing structure 53. The connecting portion of the receiving electrode 746 is formed on the insulating film 751 that covers its wide portion, and penetrates the insulating film 751 to connect with the adjacent wide portion, thereby linking them together.

[0131] The wide portion and connecting portion of the transmitting electrode 743 are formed directly on the thin film sealing structure 53. The wide portion of the receiving electrode 746 is also formed directly on the thin film sealing structure 53. These are contained within the same metal layer. The insulating film 751 covers the wide portion and connecting portion of the transmitting electrode 743 and the wide portion of the receiving electrode 746. The transmitting electrode 743 and the wide portion of the receiving electrode 746 are physically separated, and the space between them is filled with part of the insulating film 751.

[0132] The connecting portion of the receiving electrode 746 is formed in the insulating film 751 and connects to the adjacent wide portion of the receiving electrode 746 through a hole in the insulating film 751. As a result, the adjacent wide portions are connected and electrically conductive. The connecting portion of the receiving electrode 746 partially overlaps with the connecting portion of the transmitting electrode 743 in the stacking direction, but the insulating film 751 is present between them, physically separating them. This structure electrically isolates the transmitting electrode 743 and the receiving electrode 746.

[0133] The insulating film 752 covers the connecting portion between the insulating film 751 and the receiving electrode 746 on it. Multiple electrophoretic elements 714 are arranged on the insulating film 752. The transmitting electrode 743 and the receiving electrode 746 may have any structure as long as they are arranged so that they do not come into contact with each other. For example, the structural relationship between the transmitting electrode 743 and the receiving electrode 746 may be the reverse of the relationship shown in the structural examples in Figures 24 and 25.

[0134] Figure 26 shows a flowchart of a manufacturing method for a display device that includes a viewing angle control touch panel directly above a thin film encapsulation structure 53, as described in the example configuration with reference to Figures 20, 21 and 24, 25, for example. As described above, there is no substrate interposed between the thin film encapsulation structure 53 and the touch panel and electrodes for viewing angle control.

[0135] The method for manufacturing the display device involves forming a transmitting electrode and a receiving electrode on a thin film encapsulation structure 53, forming an upper louver electrode and a space for injecting electrophoretic element material into a transparent insulating film on a polyimide substrate on the opposite side of the electrode pattern layer and the electrophoretic element, and then bonding them together. Subsequently, the electrophoretic element material is injected into the space. As described above, the electrophoretic element material consists of electrophoretic particles 140 and a dispersion medium 141. The method for forming the patterns of each layer can be described with reference to Figures 18A-18H.

[0136] Referring to Figure 26, the manufacturing method involves forming patterns for the transmitting electrode (TP-Tx) and the receiving electrode (TP-Rx) and an insulating film on a thin film encapsulation structure (S31). For example, one insulating film is formed between the transmitting electrode pattern and the receiving electrode pattern, and then an insulating film covering them is formed. There are no limitations on the laminated structure including the transmitting electrode, receiving electrode and one or more insulating films, as long as the functions of the touch panel and viewing angle control are not impaired.

[0137] The manufacturing method involves forming a pattern for the upper louver electrode on a polyimide substrate in a separate process (S35), and then applying a photosensitive permanent film as a transparent material on top of it and performing pre-baking (S36). The manufacturing method involves using the pattern for the upper louver electrode as a mask to expose and develop the photosensitive permanent film using photolithography to form a transparent region (light-transmitting region). This forms a transparent region between the electrophoretic elements (S37). Alternatively, the transparent region may be formed using nanoimprint technology instead of photolithography technology.

[0138] The manufacturing method involves bonding a component including a thin film encapsulation structure and an electrode pattern thereon with a component including a polyimide substrate, an upper louver electrode, and a transparent region by pressing while heating (S41). Next, the manufacturing method involves injecting electrophoretic element material into the space formed in the transparent region (S42) and attaching a circular polarizer plate to the side of the polyimide substrate opposite the transparent insulating film (S43). This completes the apparatus.

[0139] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. Those skilled in the art can easily modify, add to, or transform each element of the above embodiments within the scope of the present invention. It is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. [Explanation of Symbols]

[0140] 1. Viewing Angle Control Touch Panel 5 Display Panel 111 Upper glass substrate 112 Lower glass substrate 121 Upper touch panel electrodes 123 Lower touch panel electrodes 114 Electrophoretic elements 131, 132, 133 Insulating film 126 Lower field of view control electrode 128 Touch Sensor IC

Claims

1. A touch panel device with a field of view control, Upper transparent substrate and Lower transparent substrate and One lower viewing angle control electrode on the upper surface of the lower transparent substrate, Multiple lower touch panel electrodes on the upper surface of the lower transparent substrate, Multiple upper touch panel electrodes on the lower surface of the upper transparent substrate, A plurality of electrophoretic elements are disposed between the lower surface of the upper transparent substrate and the upper surface of the lower transparent substrate, each containing electrophoretic particles and a dispersant. Includes, The aforementioned plurality of lower touch panel electrodes are located above the lower viewing angle control electrodes. At least a portion of each of the lower touch panel electrodes of the plurality of lower touch panel electrodes overlaps with the lower viewing angle control electrode in a plan view, Each of the multiple electrophoretic elements is sandwiched between one of the multiple upper touch panel electrodes and the lower field of view control electrode. A touch panel device with a controlled viewing angle.

2. A touch panel device with a field of view control according to claim 1, Including the controller, The controller controls the potential of the plurality of upper touch panel electrodes, the plurality of lower touch panel electrodes, and the lower field of view control electrode. The potential control by the controller includes alternating sensing periods and non-sensing periods. During the sensing period, the controller controls the potentials of the plurality of upper touch panel electrodes and the plurality of lower touch panel electrodes to perform touch sensing. During the non-sensing period, the controller controls the field of view by controlling the state of electrophoretic particles in the multiple electrophoretic elements through potential control of the multiple upper touch panel electrodes and the lower field of view control electrodes. The non-sensing period is longer than the sensing period. A touch panel device with a controlled viewing angle.

3. A touch panel device with a field of view control according to claim 2, The aforementioned controller, During the sensing period and the non-sensing period, the lower field of view control electrode is maintained at a constant potential. During the non-sensing period, the potential for controlling the field of view is applied to the plurality of upper touch panel electrodes, and the same potential as the lower field of view control electrode is applied to the lower touch panel electrode. A touch panel device with a controlled viewing angle.

4. A touch panel device with a field of view control according to claim 2, The aforementioned controller, During the sensing period and the non-sensing period, the lower field of view control electrode is maintained at a constant potential. During the sensing period, the plurality of upper touch panel electrodes are maintained at a constant potential, and the plurality of lower touch panel electrodes are sequentially selected and given a drive signal. During the non-sensing period, the potential for controlling the field of view is applied to the plurality of upper touch panel electrodes, and the same potential as the lower field of view control electrode is applied to the lower touch panel electrode. A touch panel device with a controlled viewing angle.

5. A touch panel device with a field of view control according to claim 1, A first insulating film is provided between the upper touch panel electrode and the electrophoretic element material consisting of the electrophoretic particles and the dispersant. The second insulating film between the lower touch panel electrode and the electrophoretic element material, A third insulating film between the lower viewing angle control electrode and the lower touch panel electrode, It further includes, The sheet resistances of the first insulating film, the second insulating film, and the third insulating film are in the range of 5E6Ω / □ to 5E8Ω / □. A touch panel device with a controlled viewing angle.

6. A touch panel device with a field of view control according to claim 1, The lower field of view control electrode, in a plan view, faces all electrophoretic elements between the upper transparent substrate and the lower transparent substrate. A touch panel device with a controlled viewing angle.

7. Display panel and A viewing angle control touch panel device according to any one of claims 1 to 6, positioned in front of the display panel, A display device, including a display device.

8. Display panel and A viewing angle control touch panel device according to claim 2, Includes, Each frame period includes the sensing period and the non-sensing period. Display device.

9. A display device, OLED display panel and A viewing angle control touch panel device arranged on the OLED display panel, Includes the controller, The aforementioned viewing angle control touch panel device, Multiple upper field of view control electrodes, A plurality of first touch panel electrodes and a plurality of second touch panel electrodes are arranged on the thin film encapsulation structure of the OLED display panel without a substrate in between, In the stacking direction, a plurality of electrophoretic elements, each containing electrophoretic particles and a dispersant, are arranged between the plurality of upper viewing angle control electrodes and the group of touch panel electrodes consisting of the plurality of first touch panel electrodes and the plurality of second touch panel electrodes. Includes, The aforementioned controller, The potential control of the plurality of upper field of view control electrodes is performed, and the potential control includes alternating sensing periods and non-sensing periods. During the sensing period, the potentials of the plurality of first touch panel electrodes and the plurality of second touch panel electrodes are controlled to perform touch sensing. During the non-sensing period, the field of view is controlled by controlling the state of electrophoretic particles in the plurality of electrophoretic elements using the electric field between the plurality of upper field of view control electrodes and the plurality of first and second touch panel electrodes. The non-sensing period is longer than the sensing period. Display device.

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