Touch panel device and image display device having the same

Abstract

The touch sensor panel has a plurality of sensors. The protective plate protects the touch sensor panel. The touch sensor panel and the protective plate are bonded together by a transparent adhesive material. The moisture-proof sealing material has a moisture permeability lower than that of the transparent adhesive material. The flexible wiring substrate is used to connect the plurality of sensors to an external circuit. At least a portion of the area of ​​the transparent adhesive material that is not in contact with the protective plate or the touch sensor panel is covered by the moisture-proof sealing material.

Description

[0001] This application is a divisional application based on a Chinese patent application with an application date of February 2, 2018, application number 201810108026.6, and invention name “Touch panel device and image display device having the touch panel device”. Technical Field

[0002] The present invention relates to a capacitive touch panel device and an image display device including the touch panel device. Background Art

[0003] Touch panel devices that detect touches made by a finger or other indicator and determine coordinates representing the touched position (touch coordinates) are widely used in various information processing devices. In particular, touch panel devices formed by installing a touch panel on a screen of a display device are becoming popular as new user interfaces for information processing devices.

[0004] In the projected electrostatic capacitance method, which is one of the electrostatic capacitance methods, the detection circuit detects the slight change in the electrostatic capacitance of a human finger on the touch sensor provided in the touch panel. Then, the position coordinates in the touch panel are calculated based on the detection result. According to this method, touch detection can be performed even when the front surface side of the touch panel with a built-in touch sensor is covered by a protective plate such as a glass plate with a thickness of about several mm.

[0005] The projected electrostatic capacitance touch panel device has the following advantages: excellent robustness because the protective plate can be arranged on the front surface; touch detection can be performed even when wearing gloves; and long life because there is no movable part. The protective plate of the projected electrostatic capacitance touch panel device is composed of a transparent resin substrate such as acrylic or polycarbonate or a glass substrate. When the following structure is used, that is, by setting the outer dimensions of the touch surface where the position information is input by an indicator such as a finger to be larger than the sensor surface for detecting electrostatic capacitance, so that the touch surface is suspended above the sensor surface and covers the sensor surface, a product with excellent appearance design can be provided (see patent document 1).

[0006] For such touch panel devices, since the surface operated by a finger or other indicator is made of glass, it is durable and is often used under conditions where high dielectric materials such as rain, seawater, beverages, and medicines are attached. In addition to being strong and capable of high-sensitivity detection even when wearing gloves, the performance required of projected capacitive touch panel devices is also required to be stable and not to cause false detection even when moisture is attached.

[0007] For example, Patent Document 2 discloses a touch panel device that suppresses erroneous detection even when water droplets or the like are attached.

[0008] Patent Document 1: Japanese Patent Application Publication No. 2016-224728

[0009] Patent Document 2: Japanese Patent Application Publication No. 2013-222283

[0010] In the structure of a projected capacitive touch panel device, the touch panel substrate with a built-in touch sensor and the protective plate are often bonded together by a transparent adhesive material (Optical Clear Adhesive (usually, sometimes referred to as OCA)). As the transparent adhesive material, acrylic resin is usually used, with a relative dielectric constant of about 3 to 6 and a moisture permeability of 50 to 300 g / m 2 · Materials for about 24 hours.

[0011] The relative dielectric constant of transparent adhesive material changes with temperature, and sometimes even decreases by 40% compared to room temperature in low temperature (-30°C) or high temperature (70°C) environments. In addition, the relative dielectric constant of transparent adhesive material sometimes changes due to moisture absorption. Such changes in relative dielectric constant become the cause of changes in electrostatic capacitance measured by the touch sensor.

[0012] In addition, the moisture absorbed by the transparent adhesive material enters from the part that is not covered by the protective glass (protective plate) or the touch sensor panel and is exposed to the outside air (air). Therefore, the influence is manifested as a change starting from the peripheral part of the transparent adhesive material, and the relative dielectric constant has a distribution within the surface of the transparent adhesive material. Therefore, the change in the relative dielectric constant of the transparent adhesive material not only affects the self-capacitance and mutual capacitance (Mutual capacitance) of the touch area of ​​the touch panel, but also easily affects the peripheral part of the touch panel surface. Therefore, the lead-out wiring of the touch sensor panel that is wired along the periphery of the touch sensor is also affected by this.

[0013] In particular, in a high-sensitivity touch panel device that supports the use of gloves, etc., since the electrostatic capacitance formed by the indicator is very small, the influence caused by the change in the relative dielectric constant of the transparent adhesive material becomes relatively large. In the touch panel device disclosed in Patent Document 1, the change in electrostatic capacitance coupling between the touch sensor and the metal frame of the display device and other conductive bodies when a substance with a very high relative dielectric constant (relative dielectric constant of about 80) such as water is attached to the protective glass is suppressed, thereby suppressing false detection of the touch panel.

[0014] However, as a means of suppressing the change in electrostatic capacitance coupling, a protective glass having a black frame printed with a conductive electrode and a circuit for driving the conductive electrode are required, which increases the cost of components. In addition, the influence of moisture absorption of the transparent adhesive is not particularly considered. Summary of the invention

[0015] The present invention is proposed to solve the above-mentioned problems, and its purpose is to provide a touch panel device that has high sensitivity and supports glove operation even when a protective plate is provided, and is suitable for use under high temperature and high humidity conditions, and an image display device having the touch panel device. In addition, its purpose is to provide a touch panel device and an image display device having the touch panel device that meet the following conditions, that is, by using a thick protective plate or a metal frame in the image display module, etc., the touch panel device has robustness and can suppress false detection even when water droplets are attached.

[0016] The touch panel device of the present invention comprises: a touch sensor panel, which is composed of a plurality of sensors; a protective plate, which protects the touch sensor panel; a transparent adhesive material, which bonds the touch sensor panel and the protective plate; a moisture-proof sealing material, which has a lower moisture permeability than the transparent adhesive material; and a flexible wiring substrate, which is used to connect the plurality of sensors to an external circuit. At least a portion of the area of ​​the transparent adhesive material that is not in contact with the protective plate or the touch sensor panel is covered by the moisture-proof sealing material.

[0017] Effects of the Invention

[0018] According to the present invention, at least a portion of the transparent adhesive material that is not in close contact with the protection plate and the touch sensor panel is covered with the moisture-proof sealing material, thereby preventing erroneous detection during touch coordinate detection of the capacitive touch panel device in a high humidity environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a plan view schematically showing the structure of the touch panel device according to the first embodiment.

[0020] Figure 2 is a diagram schematically showing the structure of an image display device according to Embodiment 1, and is similar to Figure 1 The corresponding cross-sectional view between AA in .

[0021] Figure 3 This is an enlarged cross-sectional view of the touch panel device according to Embodiment 1.

[0022] Figure 41 and 1 are graphs (a) showing the measurement results of the mutual capacitance of the touch panel device of the comparative example, and (b) showing the measurement results of the mutual capacitance of the touch panel device of the example of the first embodiment.

[0023] Figure 5 This is a plan view schematically showing the structure of a touch panel device according to the second embodiment.

[0024] Figure 6 is a diagram schematically showing the structure of an image display device according to Embodiment 2, and is similar to Figure 5 The corresponding cross-sectional views between BB in .

[0025] Figure 7 (a) is an enlarged cross-sectional view showing a state where water adheres to the touch panel device according to the first embodiment, and (b) is an enlarged cross-sectional view showing a state where water adheres to the touch panel device according to the second embodiment.

[0026] Figure 8 Graphs showing parasitic capacitances generated by the adhesion of water in touch panel devices of Examples 1 and 2 corresponding to Embodiments 1 and 2, respectively, normalized by self-capacitances generated by simulated fingers.

[0027] Description of the label

[0028] 1 Touch sensor panel

[0029] 2 Protection board

[0030] 3. Transparent adhesive material (OCA)

[0031] 4 Moisture-proof sealing material

[0032] 5Flexible printed circuit board (FPC)

[0033] 6Metal frame

[0034] 7 Indicator

[0035] 8. Water

[0036] 11Sensor Area

[0037] 12 Space

[0038] 14 Lead-out wiring area

[0039] 201, 202 touch panel device

[0040] 101 X Sensor

[0041] 102 Y sensor

[0042] 300 Image Display Module

[0043] 310 display area

[0044] 501, 502 image display device DETAILED DESCRIPTION

[0045] The embodiments of the present invention are described below with reference to the accompanying drawings. The following description shows preferred embodiments of the present invention, and the scope of the present invention is not limited to the following embodiments. In the following description, the same reference numerals indicate substantially the same contents.

[0046] (Implementation Method 1)

[0047] Figure 1 It is a plan view showing the structure of a projection-type touch panel device 201 according to the first embodiment. Figure 2 is a diagram schematically showing the structure of the image display device 501 according to the first embodiment, which is similar to the Figure 1 The cross-sectional view of the touch panel device 201 shown in FIG. 2 is a portion (between AA) indicated by a single-dot chain line. Figure 1 As shown, the projection type touch panel device 201 includes a touch sensor panel 1, a protective plate 2, a transparent adhesive material 3, a moisture-proof sealing material 4, and a flexible printed circuit (FPC) substrate.

[0048] 5. The touch sensor panel 1 comprises: a sensor area 11 which is touched by a pointer; and

[0049] The lead wiring area 14 is used to connect multiple sensors to the FPC 5. The multiple sensors are connected to the external circuit through the FPC 5. Figure 2 As shown, the touch panel device 201 is installed on the image display module 300. The image display module has a display area 310 covered by the touch panel device 201. Figure 2 As shown, there may be a gap between the touch panel device 201 and the display area 310 .

[0050] also, Figure 2 The image display device 501 is schematically recorded, and illustrations of touch panel controller substrate (external circuit), image display module (liquid crystal display device in this embodiment), host equipment and cable-type structural elements that are actually necessary but unnecessary in the following description are omitted.

[0051] The touch sensor panel 1 includes, as sensors for detecting touch, a plurality of X sensors 101 (sensors for detecting coordinates in the X direction) extending in the vertical direction and arranged in the horizontal direction, and a plurality of Y sensors 102 (sensors for detecting coordinates in the Y direction) extending in the horizontal direction and arranged in the vertical direction. That is, the plurality of X sensors 101 and the plurality of Y sensors 102 are arranged to be orthogonal to each other. Figure 1 In order to simplify the diagram, five X sensors and four Y sensors are shown as the sensor structure. In each sensor, due to the influence of the common electrode of the liquid crystal display module to which the touch sensor panel 1 is attached, etc., there is a parasitic self-capacitance between the sensor and the image display module 300. In addition, there is a mutual capacitance between the X sensor and the Y sensor.

[0052] Each sensor of the touch sensor panel 1 is connected to a lead wire provided at the periphery of the touch area of ​​the touch sensor panel 1 (lead wire area 14). The lead wire is wired along the periphery of the touch sensor panel 1 and is connected to a terminal portion 105 surrounded by a dotted line in the figure. A shield wire 106 is provided between the Y sensor lead wire 103 and the X sensor lead wire 107, and the shield wire 106 is used to shield the influence of the parasitic capacitance between the electrodes between the X sensor and the Y sensor. In addition, a shield wire 104 is provided between the Y sensor lead wire 103 and the periphery of the touch sensor panel, and the shield wire 104 is used to shield the influence of the parasitic capacitance between the Y sensor and other nearby electrodes. The terminal portion 105 is connected to a touch panel controller (not shown) via the FPC 5 indicated by a dotted line.

[0053] The touch panel controller is configured to have a built-in circuit for measuring electrostatic capacitance, measure the self-capacitance or mutual capacitance of each sensor, and detect changes in electrostatic capacitance caused by contact between a finger or other indicator and the protection plate.

[0054] The touch panel controller also includes means for determining the position of the indicator using a built-in calculation circuit based on the detection result and transmitting touch information indicating the presence or absence of touch and coordinates of the indicator to a host device (not shown).

[0055] The X sensor 101 and the Y sensor 102 are usually electrodes formed by placing a transparent conductive film (ITO: Indium Tin Oxide) or a metal ultra-fine wiring of a few micrometers in width on a glass substrate or a film substrate so that the transmittance is greater than or equal to 80%. An interlayer film is provided between the X sensor 101 and the Y sensor 102. In order to protect the X sensor 101 and the Y sensor 102, they are covered with a thin protective film.

[0056] The touch sensor panel 1 is bonded to the protective plate 2 by a transparent adhesive material 3 in a manner that does not include an air layer. In order to maintain durability, the protective plate 2 is made of glass that has been subjected to chemical strengthening treatment to improve durability and damage resistance. The material of the transparent adhesive material 3 is generally an acrylic resin, etc., with a relative dielectric constant of about 3 to 6 and a moisture permeability of 50 to 300 [g / m 2 ·24hr] about.

[0057] The transparent adhesive material 3 is attached to the touch sensor panel 1 and the protective plate 2 in a humidity-controlled environment. The surface of the transparent adhesive material 3, except for the surface in close contact with the touch sensor panel 1 and the surface in close contact with the protective plate 2, that is, the side surface of the transparent adhesive material 3 (at the Figure 1 Along the four edges of the face, Figure 2 In order to prevent the left and right sides (in the middle) from contacting with the outside air, these sides are sealed with moisture-proof sealing material 4.

[0058] The touch panel device 201 is attached to the metal frame 6 of the image display module 300 by means of a double-sided adhesive tape 9. As a modified example, in order to reduce external light reflection or improve the transmittance of the image display module, not only the protection plate 2 and the touch sensor panel 1 but also the touch panel device 201 and the image display module 300 may be attached by means of a transparent adhesive material.

[0059] The moisture permeability of the moisture-proof sealing material 4 is preferably sufficiently lower than that of the transparent adhesive material 3. The relative dielectric constant of the moisture-proof sealing material 4 is preferably smaller than that of the transparent adhesive material 3. Specifically, "HumiSeal 1B58LU" of Chase Co., Ltd., which has a polyolefin resin as a main component, is used. The moisture permeability of HumiSeal 1B58LU is 6.0 [g / m 2 ·24h], which is 1 / 10 to 1 / 50 of the moisture permeability of ordinary transparent adhesive materials and is very small. In addition, its relative dielectric constant is also sufficiently small, at 2.0.

[0060] Next, the influence of a change in the relative dielectric constant of the transparent adhesive 3 will be described. Figure 3 Schematically show Figure 2. When measuring the mutual capacitance between the X sensor 101 and the Y sensor 102, an excitation signal (rectangular wave of about 100 kHz, etc.) is applied to the Y sensor 102, while the X sensor 101 is measured by the electrostatic capacitance detection circuit (composed of an integration circuit, an amplifier, an analog-to-digital conversion circuit (A / D), etc.) not shown. In order to improve the sensitivity of touch detection, the X sensor 101 and the Y sensor 102 are arranged so that the area where they overlap each other is reduced and the area where they are arranged on the plane is increased. Therefore, between the X sensor 101 and the Y sensor 102, the power lines 10a and 10b are widened as shown in the figure. Therefore, the mutual capacitance between these sensors is affected by the dielectric just above the X sensor 101 and the Y sensor 102.

[0061] There is a transparent adhesive material 3 just above the sensor, and there is a protective plate 2 on top of the transparent adhesive material 3. Therefore, the mutual capacitance described above can be affected by the dielectrics of both the transparent adhesive material 3 and the protective plate 2. Although it is also related to their respective thicknesses, since the dielectric just above the sensor is the transparent adhesive material 3, if the relative dielectric constant of the transparent adhesive material 3 changes, the mutual capacitance between the X sensor 101 and the Y sensor 102 also changes.

[0062] Figure 3 The mutual capacitance between the X sensor 101 and the Y sensor 102 shown is also slightly affected by the shield wiring 104 connected to the ground (GND), and this influence is also affected by the change in the relative dielectric constant of the transparent adhesive material 3.

[0063] In a capacitive touch panel device, even when the indicator (not shown) is not touching, a fixed parasitic capacitance exists in each sensor. Therefore, the value measured when the indicator is not touching is used as a reference value (reference line), and the difference between the reference value and the measured value at each time is regarded as the change in electrostatic capacitance caused by the touch of the indicator, and the presence or absence of touch and the position coordinates are calculated.

[0064] In the highly sensitive touch panel device 201 that can be operated even when wearing thick gloves, it is preferable that the change in electrostatic capacitance due to other factors other than the intentional operation of the pointer be as small as possible.

[0065] In order to stabilize the operation of the highly sensitive touch panel device 201, it is preferred that the relative dielectric constant of the transparent adhesive material 3 has a small change. According to this embodiment, the moisture-proof sealing material 4 blocks the external air (see FIG. 1 ) that attempts to intrude into the transparent adhesive material 3. Figure 3 As a result, the transparent adhesive material 3 is not easily affected by the humidity of the external air. Therefore, the touch panel detection operation in a high humidity environment is stabilized.

[0066] exist Figure 3 In the description of the mutual capacitance between the X sensor 101 and the Y sensor 102, the Y sensor lead wire 103 and the shield wire 104 which are wired along the periphery of the touch sensor panel 1 may also be affected by the transparent adhesive material 3 just above the wires.

[0067] In addition, if it is assumed that the moisture-proof sealing material 4 ( Figure 3 ), then the transparent adhesive material 3 from the arrow ( Figure 3 ) direction, that is, the side surface is exposed to the outside air. As a result, moisture contained in the outside air is absorbed into the transparent adhesive material 3. As a result, the touch panel detection operation in a high humidity environment becomes unstable.

[0068] [Compare]

[0069] Figure 4 The results of measuring the mutual capacitance of the touch panel device after a high temperature and high humidity test (temperature 60°C, relative humidity 90%, period 500 hours) are shown. Specifically, Figure 4 (a) is a diagram of a comparative example without the moisture-proof sealing material 4, Figure 4 (b) is a diagram of an example of the present embodiment 1. In the comparative example and the example, the touch sensor panel 1 is composed of 27 X sensors (with Figure 4 X0 to X26 in the image) and 16 Y sensors (corresponding to Figure 4 The Y0 to Y15 correspond to each other) and are cross-constructed in a matrix shape.

[0070] according to Figure 4 (a) It can be seen that the mutual capacitance value of the touch panel device of the comparative example has a large non-uniformity within the surface, and in particular, the four corners have a significantly large mutual capacitance. According to the measurement results, the relative dielectric constant of the transparent adhesive material 3 after the high temperature and high humidity test is not uniform within the surface, and has the largest relative dielectric constant at the four corners. This uneven distribution is believed to be due to the four sides ( Figure 1 In this case, the four corners absorb the most moisture and the center absorbs the least moisture, and as a result, it is considered that the mutual capacitance value is attenuated toward the center.

[0071] On the other hand, according to Figure 4 (b) It can be seen that the mutual capacitance value of the touch panel device of the embodiment has a relatively small change in the plane, and the decrease in the center is also smaller than that in the four corners. This is considered to be because the four sides ( Figure 1The upper, lower, left and right edges in the adhesive are isolated from the outside air, thereby suppressing the absorption of moisture into the transparent adhesive material 3.

[0072] In the comparative example, Figure 1 The mutual capacitance within the surface of the sensor area 11 represented by the dotted line in FIG. Figure 4 (a) The effect of moisture absorption shown in the figure. When the effect is of a size that cannot be ignored relative to the electrostatic capacitance detection range (dynamic range) of the touch panel controller, the capacitance change caused by the touch operation produces an error, and as a result, the error of the calculated coordinates increases. In addition, in the case of a larger effect, the change caused by the touch cannot be captured by the detection circuit because the detection circuit exceeds the range, so the touch cannot be detected.

[0073] On the contrary, when the transparent adhesive material 3 that has fully absorbed water is exposed to a dry environment, the amount of water absorbed sometimes decreases from the periphery, and the result is as follows: Figure 4 The mutual capacitance distribution of (a) is reversed, that is, the capacitance value is high in the center and low in the periphery. In this case, the mutual capacitance within the sensor area 11 is affected by dryness. This affects the capacitance detection operation of the touch panel device 201.

[0074] According to the above comparison results, in the touch panel device 201 of the present embodiment, moisture absorption of the transparent adhesive material 3 is prevented by isolating the outside air with the moisture-proof sealing material 4. As a result, the change in the relative dielectric constant of the transparent adhesive material 3 in the high temperature and high humidity environment is suppressed. Therefore, the change in the self-capacitance of each sensor (X sensor 101 and Y sensor 102) of the touch sensor panel 1 and the change in the mutual capacitance between the sensors caused by the influence of the transparent adhesive material 3 are reduced. Therefore, the touch coordinate detection operation of the touch panel in the high temperature and high humidity environment can be stabilized.

[0075] In the first embodiment, the touch sensor panel 1 including the X sensors 101 and the Y sensors 102 arranged in a matrix is ​​described. However, the same effect can be obtained in a segment type touch panel including a plurality of touch electrodes arranged on the touch panel surface.

[0076] In addition, it is most preferred that the moisture-proof sealing material 4 is placed on the side of the transparent adhesive material 3 that would be exposed to the outside air if there is no moisture-proof sealing material 4 ( Figure 1 However, even if the moisture-proof sealing material 4 is omitted, a certain degree of effect can be obtained in places where the area in contact with the outside air is small, such as the gap between the FPC 5 and the protective plate 2.

[0077] Furthermore, when the influence of parasitic capacitance between the lead wires (the Y sensor lead wires 103 and the X sensor lead wires 107) and the shield wires (the shield wires 104 and 106) or between the lead wires (the Y sensor lead wires 103 and the X sensor lead wires 107) and the metal frame 6 is large, only the side surfaces of the moisture-proof sealing material 4 along the lead wires (the Y sensor lead wires 103 and the X sensor lead wires 107) having large influence may be sealed. According to such a structure, the cost-effectiveness ratio may be increased.

[0078] That is, by covering at least a portion of the area of ​​the moisture-proof sealing material 4 that is not in contact with the protection plate 2 or the touch sensor panel 1 with the moisture-proof sealing material 4 , it is expected that the coordinate detection operation of the touch panel device 201 in a high-temperature and high-humidity environment will be stabilized.

[0079] In the example of the present embodiment, at the touch sensor panel 1, a silicon dioxide film (SiO2) with a film thickness of 1 micrometer is used as an interlayer film between the X sensor 101 and the Y sensor 102, and a protective insulating film for protecting the X sensor 101 and the Y sensor 102. When the interlayer film and the protective insulating film are thin as described above, the influence of the change in the dielectric constant of the transparent adhesive material 3 is large. Therefore, in this case, the effect obtained by suppressing the change in the relative dielectric constant of the transparent adhesive material 3 by setting the moisture-proof sealing material 4 is particularly large. In addition, in recent years, in order to improve the electrostatic breakdown resistance of the touch sensor panel 1, the protective insulating film is sometimes set slightly thicker, but if the film thickness is less than or equal to 2 micrometers, a relatively large effect can be obtained. That is, if the distance from the sensor electrode surface of the touch sensor panel 1 (the surface of the X sensor 101 or the Y sensor 102) to the transparent adhesive material 3 is less than or equal to 2 micrometers, a relatively large effect can be obtained.

[0080] On the other hand, when the touch sensor panel 1 is formed by bonding a glass plate on which the X sensors 101 are formed and a glass plate on which the Y sensors 102 are formed, that is, when the touch sensor panel 1 is formed of two glass plates, since the glass plates are located right above the sensors, the influence of the change in the dielectric constant of the transparent adhesive 3 is slightly small, and the above-mentioned effect can be obtained to a certain extent.

[0081] (Implementation Method 2)

[0082] Figure 5 It is a plan view showing the structure of a touch panel device 202 according to the second embodiment. Figure 6 is a diagram schematically showing the structure of the image display device 502 according to the first embodiment, which is similar to the Figure 5The touch panel device 202 shown in FIG. 1 is a cross-sectional view corresponding to the portion (between BB) indicated by the single-dot chain line in the figure. Figure 1 The position and size of the transparent adhesive material 3 are selected so as to cover the sensor area 11 indicated by the dotted line and not cover a part of the lead wiring area 14. Therefore, the sensor area 11 in the touch sensor panel 1 is covered by the transparent adhesive material 3 directly above, and a space 12 not covered by the transparent adhesive material 3 is provided above a part of the lead wiring area 14. Except for this point, the structure of the image display device 502 of this embodiment is the same as that of the image display device 501 of embodiment 1.

[0083] Figure 7 (a) and Figure 7 (b) schematically shows the water 8 adhering to the touch panel device 201 ( Figure 2 ) and the touch panel device 202 ( Figure 6 ). In addition, these figures also show an equivalent circuit of parasitic capacitance associated with the metal frame 6 of the image display module 300 (not shown) when a touch is made by the indicator 7. In addition, the same is true when a high dielectric material such as salt water, beverages, or medicines is attached instead of water 8.

[0084] exist Figure 7 , a capacitance is formed between the indicator 7 (finger) and the X sensor 101a of the touch sensor panel 1. Since the protective plate 2 and the transparent adhesive material 3 are present between the indicator 7 and the X sensor 101a of the touch sensor panel 1, the formed capacitance is a capacitance corresponding to the series connection of the capacitance 701a formed by the protective plate 2 and the capacitance 701b formed by the transparent adhesive material 3.

[0085] This capacitance varies depending on the width of the X sensor 101a, the state of the indicator 7 (contact area with the protective plate 2, presence or absence of gloves, etc.), the thickness and relative dielectric constant of the protective plate 2 and the transparent adhesive material 3, but is generally less than about 1 pF. In particular, in the case of operation with thick gloves such as work gloves, this value is further reduced to about 1 / 3. The capacitance change caused by the difference between the presence of the indicator 7 and the absence of the indicator 7 is used to determine the presence or absence of touch and calculate the finger position in the touch area.

[0086] exist Figure 7 7 shows the human body capacitance 702 of the indicator 7. The human body capacitance 702 also depends on the volume of the body, but is generally about 40 to 100 pF, which is 10 times or more of the capacitance between the indicator 7 and the X sensor 101a and is sufficiently large. Therefore, the indicator 7 can be regarded as being substantially grounded to the ground (GND).

[0087] exist Figure 7 , the X sensor 101b is the sensor located at the outermost periphery among the plurality of X sensors 101. Due to the capacitive coupling via the water 8 having a high dielectric constant (about 80), the self-capacitance of the X sensor 101b when the water 8 is attached to the outer periphery of the protection plate 2 is proportional to the following electrostatic capacitance, that is, the electrostatic capacitance corresponding to the series connection of the capacitors 801a, 801b, 801c, 801d and 801e in the figure. In addition, the capacitor 801a is the capacitance between the outermost peripheral X sensor 101b and the protection plate 2, the capacitors 801b and 801c are the capacitances between the protection plate 2 and the water 8, the capacitor 801d is the capacitance between the protection plate 2 and the touch sensor panel 1, and the capacitor 801e is the capacitance between the transparent adhesive material 3 and the metal frame 6.

[0088] If the capacitance between the outermost X sensor 101b and the metal frame 6 formed when the water 8 with a high dielectric constant (about 80) is attached exceeds the threshold value for determining the presence or absence of the touch of the indicator 7, it is impossible to distinguish the influence caused by the water 8 from the touch of the indicator 7 (finger). Therefore, this becomes a cause of false detection. In the case of a high-sensitivity touch panel that supports glove operation, the threshold for determining the presence or absence of the touch of the indicator 7 is set to be smaller, so the influence caused by the attachment of water 8 becomes particularly large.

[0089] In the touch panel device 201 (embodiment 1), a transparent adhesive material 3 (relative dielectric constant of about 3 to 6) is provided directly above the area overlapping the metal frame 6 in the touch sensor panel 1. On the other hand, in the touch panel device 202 (embodiment 2), the transparent adhesive material 3 is not provided above the corresponding area, but a space 12 is provided. Since the space 12 is composed of air with a relative dielectric constant of 1, the capacitance 801d in the case of embodiment 2 becomes smaller. Therefore, the parasitic capacitance between the outermost X sensor 101b and the metal frame 6 formed by the influence of the adhesion of the water 8 is reduced due to the presence of the space 12.

[0090] Figure 8 In the touch panels of Examples 1 and 2 corresponding to Embodiment 1 and Embodiment 2, respectively, the parasitic capacitance value between the outermost peripheral X sensor 101 b and the metal frame 6 of the image display module 300 is plotted by relative contrast based on the self-capacitance value corresponding to the sensitivity of an artificial finger when water 8 is attached to the outer periphery of the protection plate 2 (the attached area is twice the size of a circle with a diameter of 7 mm). Figure 8The value 13a is the self-capacitance value when a simulated finger (a brass rod in contact with a circle with a diameter of 7 mm) is arranged as an indicator 7 in a touch panel device composed of a 0.7 mm thick glass protective plate 2 (relative dielectric constant 5.8), a 0.5 mm thick touch sensor panel 1 (relative dielectric constant 5.8), and a 0.2 mm thick transparent adhesive material 3 (relative dielectric constant 5.8).

[0091] The self-capacitance value was normalized as 100%, and the parasitic capacitance value between the outermost peripheral X sensor 101b and the metal frame 6 of the image display module 300 when water 8 was attached to the outer periphery of the protection plate 2 (the attached area was twice the diameter of a circle of 7 mm) was compared between Example 1 and Example 2. Figure 8 The parasitic capacitance value in Example 1 (corresponding to the above-mentioned Embodiment 1) represented by value 13b is 56%, and the parasitic capacitance value in Example 2 (corresponding to the present Embodiment 2) represented by value 13c is 43%. This means that, compared with Embodiment 1 ( Figure 2 ) is different, such as implementation mode 2 ( Figure 6 ) as shown, in the metal frame 6 ( Figure 6 ) in the overlapping area, since the transparent adhesive material 3 is not provided directly above the touch sensor panel 1, the parasitic capacitance value is reduced by, for example, 13%.

[0092] The reduction in the parasitic capacitance value has the following effect: when the touch panel device is made more sensitive to support operation performed while wearing thick gloves, and the threshold for determining touch is lowered, the false detection rate when water 8 is attached is reduced. Figure 7 Although not described in the specification, since the transparent adhesive material 3 does not exist in the outer periphery in the second embodiment, the parasitic capacitance value between the outermost X sensor 101b and the shield wiring (shield wiring 104, 106) (GND potential in the touch sensor panel 1) due to the influence of the adhesion of water 8 is also reduced in the same manner.

[0093] Therefore, in the second embodiment, in addition to the effect of the first embodiment, an effect of reducing erroneous detection of touch coordinates when water 8 adheres to the outer peripheral portion of the protection plate 2 is obtained.

[0094] In the first and second embodiments, as the moisture-proof sealing material 4, Chase's "Hydroxysil" (water permeability 6.0 [g / m 2· 24h]), but if the portion of the transparent adhesive material 3 that can be exposed to the outside air is sealed with a material having a lower moisture permeability than the transparent adhesive material 3, an effect can be obtained. For example, "Tap" (50g / m 2 · 24h (temperature 40°C / relative humidity 90%), etc., the same effect can be expected. In addition, the moisture-proof sealing material 4 is not limited to the coating type. By pasting a polyimide film tape such as "Kapton tape" as the moisture-proof sealing material 4 in a manner that covers the four sides of the transparent adhesive material 3 so that the transparent adhesive material 3 does not come into contact with the outside air, the same effect can be expected.

[0095] Furthermore, in the above-mentioned Embodiments 1 and 2, the touch panel device and the image display module may be bonded together using a transparent adhesive material instead of the double-sided tape. In this case, the four sides ( Figure 1 Of course, in order to prevent moisture absorption from the four edges exposed to the outside air to the transparent adhesive material, the four edges can be covered with a moisture-proof sealing material with low moisture permeability.

[0096] Furthermore, the present invention can freely combine the various embodiments within the scope of the invention, and can appropriately modify or omit the various embodiments.

Claims

1. A touch panel device comprising: a touch sensor panel having a plurality of sensors; A protection plate, which protects the touch sensor panel; a transparent adhesive material for bonding the touch sensor panel and the protection plate; a sealing member that seals side surfaces of the transparent adhesive material except for surfaces in contact with the touch sensor panel and the protection plate; as well as A flexible wiring substrate for connecting the plurality of sensors to an external circuit, Among them, the touch panel device is adhered to the metal frame of the image display module, the touch sensor panel includes a lead-out wiring area, which is used to connect the multiple sensors to the flexible wiring substrate, and the transparent adhesive material does not cover the portion of the lead-out wiring area that overlaps with the metal frame to set up a space composed of air.

2. The touch panel device according to claim 1, characterized in that: The touch sensor panel also includes a sensor area, which is touched by a pointer, The transparent adhesive material covers the sensor area.

3. The touch panel device according to claim 1 or 2, characterized in that: A distance from a sensor electrode surface of the touch sensor panel to the transparent adhesive material is less than or equal to 2 micrometers.

4. An image display device comprising: The touch panel device according to any one of claims 1 to 3; and The image display module has a display area covered by the touch panel device, and the touch panel device is attached to the metal frame of the image display module through a double-sided tape or a transparent adhesive material.

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