Touch sensor and position detection device

Abstract

The invention relates to a touch sensor and a position detection device. An electronic device (10) is provided with: a differential amplifier (30) that differentially amplifies and outputs a positive-side signal and a negative-side signal selectively output from a plurality of electrodes (20) included in a touch sensor (14); and a conductive member (56) that is formed of a conductive material or contains a conductive material, and that is disposed so as to partially overlap with a sensor region (R) formed by the touch sensor (14) in plan view. The conductive member (56) is disposed such that an end point (62) closest to the outside in the arrangement direction is positioned on any one of the plurality of electrodes (20).

Description

[0001] This application is a divisional application of the application with the application number 202080042156.X and the invention title "Electronic device", which was filed on December 7, 2021. Technical Field

[0002] The present invention relates to an electronic device, a touch sensor, and a position detection device. Background Art

[0003] In Patent Document 1, a position detection device of a so-called "differential amplification method" is disclosed, which differentially amplifies and outputs a signal between a positive-side electrode and a negative-side electrode of a touch sensor. By obtaining the difference between signals from two mutually parallel electrodes, an effect of canceling common-mode noise generated in the same direction can be obtained.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Laid-Open No. 8-095701 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] Inside an electronic device, in addition to a touch sensor, there is also a component made of a conductive material or containing a conductive material (hereinafter referred to as a conductive component). By generating electromagnetic interference with this conductive component, common-mode noise may be mixed into the detection signal of the touch sensor. Usually, this conductive component has a smaller size than the sensor area formed by the touch sensor and is arranged so as to partially overlap the sensor area when viewed from above. Therefore, the magnitude of the noise contained in the detection signal may vary depending on the position within the sensor area.

[0009] However, in the differential amplification method as in Patent Document 1, when the magnitudes of the noise mixed into the signal of the positive-side electrode and the signal of the negative-side electrode are different, the canceling effect of the common-mode noise cannot be obtained, and the influence of the noise becomes greater due to amplification.

[0010] An object of the present invention is to provide an electronic device that can consider the relationship with a conductive component that may be a noise generation source and further exert the canceling effect of the differential amplification method on noise.

[0011] Means for Solving the Problems

[0012] The electronic device in the first invention includes: a touch sensor configured to include a plurality of electrodes that are separated from each other along the arrangement direction and arranged in a planar shape; a differential amplifier that differentially amplifies and outputs the difference between the positive-side signal and the negative-side signal selectively output from the plurality of electrodes; a position detection unit that detects a touch position within a sensor region formed by the touch sensor based on an output signal from the differential amplifier; and a conductive member that is made of a conductive material or includes a conductive material and is arranged so as to partially overlap the sensor region in a top view, and the conductive member is arranged such that the outermost end point in the arrangement direction is located on any one of the plurality of electrodes.

[0013] The touch sensor in the second invention is a sensor used together with a display panel that drives a plurality of pixels by applying a driving voltage to matrix-shaped signal lines arranged in a row direction and a column direction and can display an image or video within a display region. The touch sensor is arranged so as to at least partially overlap the display region in a top view and is configured to include a plurality of electrodes arranged in a rectangular shape. The plurality of electrodes include: a plurality of first electrodes that extend in a first direction and are arranged separately from each other along a direction orthogonal to the first direction; and a plurality of second electrodes that extend in a second direction intersecting the first direction and are arranged separately from each other along a direction orthogonal to the second direction, and at least one of the first direction and the second direction is inclined with respect to both the row direction and the column direction.

[0014] The position detection device in the third invention includes: the touch sensor in the second invention; and a position detection unit that detects a touch position within a sensor region formed by the touch sensor based on a detection signal from the touch sensor.

[0015] Advantages of the Invention

[0016] According to the first invention, it is possible to consider the relationship with the conductive member that may be a noise generation source and further exert the noise cancellation effect of the differential amplification method.

[0017] According to the second and third inventions, it is possible to suppress the mixing of common-mode noise caused by electronic interference with the display panel into the detection signal of the touch sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a circuit structure diagram related to the position detection function of the electronic device in the first embodiment of the present invention.

[0019] Figure 2 is Figure 1 an exploded perspective view of the electronic device shown.

[0020] Figure 3 is a diagram showing Figure 2 the relative positional relationship among the main substrate, the display panel, and the touch sensor shown.

[0021] Figure 4 is Figure 3 an enlarged view of part A of

[0022] Figure 5 is Figure 3 an enlarged view of part B of

[0023] Figure 6A is a diagram showing Figure 4 another structure of the heat dissipation plate of

[0024] Figure 6B is a diagram showing Figure 4 another structure of the heat dissipation plate of

[0025] Figure 7 is a diagram showing a comparative example corresponding to Figure 4

[0026] Figure 8 is a diagram showing the effect achieved by the configuration relationship of Figure 4

[0027] Figure 9 is the circuit structure diagram related to the position detection function of the electronic device in the second embodiment of the present invention.

[0028] Figure 10 is Figure 9 an exploded perspective view of the electronic device shown.

[0029] Figure 11 is a diagram showing Figure 10 the structure of the driving circuit included in the display panel of

[0030] Figure 12A is a schematic diagram related to the line inversion driving method.

[0031] Figure 12B is a schematic diagram related to the line inversion driving method.

[0032] Figure 13 is Figure 9 an enlarged partial view of the first electrode shown.

[0033] Figure 14 is Figure 9 and Figure 10 a top view of the touch sensor shown.

[0034] Figure 15A is for explaining by Figure 14 ​​A diagram showing a comparative example when illustrating the first effect achieved by the touch sensor.

[0035] Figure 15B This is when explaining Figure 14 A diagram showing an embodiment when illustrating the first effect achieved by the touch sensor.

[0036] Figure 16A This is when explaining Figure 14 A diagram showing a comparative example when illustrating the second effect achieved by the touch sensor.

[0037] Figure 16B This is when explaining Figure 14 A diagram showing an embodiment when illustrating the second effect achieved by the touch sensor. Detailed implementation manners

[0038] Hereinafter, preferred embodiments of the electronic device, touch sensor, and position detection device in the present invention will be given, and explanations will be made while referring to the appended Figure 1 It should be noted that the present invention is not limited to the following embodiments and variations, and can of course be freely changed without departing from the gist of the present invention. Alternatively, the respective structures can be arbitrarily combined within the range where no technical contradiction occurs.

[0039] [First Embodiment]

[0040] Hereinafter, explanations will be made while referring to Figures 1 - 8 the electronic device in the first embodiment of the present invention.

[0041] <Circuit Structure of Electronic Device 10>

[0042] Figure 1 This is a circuit structure diagram related to the position detection function of the electronic device 10 in the first embodiment of the present invention. The electronic device 10 is constituted by, for example, a flat panel terminal, a smart phone, or a personal computer. A user can write drawings and characters on the electronic device 10 by holding the electronic pen 12 and moving it while bringing the tip into contact with the touch surface of the electronic device 10. The electronic pen 12 is, for example, a stylus of the active electrostatic method (AES) or the electromagnetic induction method (EMR).

[0043] Specifically, the electronic device 10 is configured to include a touch sensor 14 that detects the approach of a conductive body such as the electronic pen 12 or the user's finger, an integrated circuit (IC: Integrated Circuit; hereinafter, touch IC 16) for controlling the touch sensor 14, and a host processor 18 electrically connected to the touch IC 16.

[0044] The touch sensor 14 is overlapped and arranged on the display panel 44 ( Figure 2) capacitive touch sensor. The touch sensor 14 can be a mutual capacitance type sensor or a self-capacitance type sensor. The touch sensor 14 is configured to include a plurality of electrodes 20 that are separated from each other along the arrangement direction and are arranged in a planar manner. The material of the electrode 20 can be indium tin oxide (ITO), or can be a metal such as copper, silver, or gold.

[0045] The linear or strip-shaped electrode 20 includes a first electrode 21 for detecting the position (X coordinate) in the X direction and a second electrode 22 for detecting the position (Y coordinate) in the Y direction. The first electrode 21 and the second electrode 22 are insulated from each other by being sandwiched by an insulating substrate (not shown) made of glass or resin. The plurality of first electrodes 21 are arranged to extend in the Y direction, and are separated from each other along the X direction and arranged at equal intervals. The plurality of second electrodes 22 are arranged to extend in the X direction, and are separated from each other along the Y direction and arranged at equal intervals. That is, the X direction and the Y direction shown in this figure correspond to the X axis and the Y axis of the "sensor coordinate system" defined within the sensor area As formed in the touch sensor 14. In this first embodiment, the sensor coordinate system is consistent with the "display coordinate system" defined within the display area formed in the display panel 44 ( Figure 2 ).

[0046] The touch IC 16 is configured to include an X selection circuit 24, a Y selection circuit 26, a switch 28, a differential amplifier 30, a band-pass filter (hereinafter referred to as the BP filter 32), a detection circuit 34, an AD converter 36, and a microprocessor unit (hereinafter referred to as the MCU 38).

[0047] The X selection circuit 24 is a multiplexer connected to the plurality of first electrodes 21 respectively. The X selection circuit 24 selects two electrodes from the plurality of first electrodes 21 according to an instruction signal from the MCU 38, and outputs two types of signals (X positive side signal and X negative side signal) from each electrode simultaneously. The Y selection circuit 26 is a multiplexer connected to the plurality of second electrodes 22 respectively. The Y selection circuit 26 selects two electrodes from the plurality of second electrodes 22 according to an instruction signal from the MCU 38, and outputs two types of signals (Y positive side signal and Y negative side signal) from each electrode simultaneously.

[0048] The switch 28 is connected to the output sides of the X selection circuit 24 and the Y selection circuit 26 respectively. The switch 28 selectively outputs either the positive side signal or the negative side signal according to an instruction signal from the MCU 38. The differential amplifier 30 amplifies the difference between the positive side signal and the negative side signal selectively output from the plurality of electrodes 20 through the switch 28 and outputs it.

[0049] The BP filter 32 is a filter circuit that passes a prescribed frequency band width centered on the frequency corresponding to the output signal from the electronic pen 12. The detection circuit 34 is a circuit that generates a detection signal based on the output signal that has passed through the BP filter 32. The AD converter 36 is a signal converter that converts an analog signal into a digital signal.

[0050] The MCU 38 is a device that can process the digital signal output from the AD converter 36 to detect the touch position within the sensor area As. The MCU 38 reads and executes a position detection program from a memory (not shown), thereby exercising a "pen detection function" for detecting the state of the electronic pen 12 and a "touch detection function" for detecting touches by the user's finger or the like.

[0051] The pen detection function includes, for example, the scanning function of the touch sensor 14 (global scanning or sector scanning), the reception and analysis function of the downlink signal, the estimation function of the state of the electronic pen 12 (e.g., position, posture, pen pressure), and the generation and transmission function of the uplink signal including instructions for the electronic pen 12. In addition, the touch detection function includes, for example, the scanning function of the touch sensor 14, the creation function of the detection map (two-dimensional distribution of detection levels) within the sensor area As, and the area classification function on the detection map (e.g., classification of finger, palm, etc.).

[0052] The host processor 18 is composed of a processing and arithmetic device including a CPU (Central Processing Unit), an MPU (Micro-Processing Unit), and a GPU (Graphics Processing Unit). The host processor 18 can execute various functions including the generation of digital ink, the production of image signals, and the control of data transmission and reception by reading and executing a program stored in a memory (not shown).

[0053] <Device Structure of the Electronic Device 10>

[0054] Figure 2 is Figure 1 the exploded perspective view of the electronic device 10 shown. Figure 3 is a view showing Figure 2A diagram showing the relative positional relationship among the main substrate 42, the display panel 44, and the touch sensor 14. The electronic device 10 is constituted by sequentially overlapping a back cover 40, a main substrate 42, a display panel 44, a touch sensor 14, and a front cover 46 from the back side. In the example of this figure, the touch sensor 14 is an "externally mounted type" sensor mounted on the display panel 44 from the outside, but instead, it can be a sensor of "built-in type" (if further classified, it is an on-cell type or an in-cell type) integrally formed with the display panel 44.

[0055] The back cover 40 and the front cover 46 are members constituting a housing for accommodating electronic components within the electronic device 10. In the front cover 46, a highly transparent protective panel 48 is provided so as to cover the entire surface of an opening formed in its main surface.

[0056] The display panel 44 is constituted by, for example, a liquid crystal panel, an organic EL (Electro Luminescence) panel, an electronic paper, or the like. The display panel 44 drives a plurality of pixels by applying a driving voltage to matrix-shaped signal lines arranged in the row direction and the column direction, thereby displaying an image or video within a display area.

[0057] The main substrate 42 is a substrate constituting a circuit for operating the electronic device 10. As Figure 3 shown, on the main substrate 42, in addition to the above-described touch IC 16 and host processor 18, a connector 50 and various electronic components 52 are also arranged. The connector 50 is configured to be able to electrically connect a flexible printed circuit board (hereinafter, FPC board 54) provided at an end portion of the touch sensor 14 and the touch IC 16. As examples of the electronic components 52, a driving IC of the display panel 44, a memory, a wireless communication module, a power supply circuit, an electronic component (for example, a coil), or the like can be cited.

[0058] Electronic components including a processor sometimes have a degraded processing performance or malfunction due to an increase in the internal temperature or the ambient temperature. In order to suppress this phenomenon, a heat sink or a heat conduction path for discharging heat generated inside the device is sometimes provided in the electronic device 10. In the example of this figure, a heat sink 56 (conductive member) containing a conductive material such as aluminum (Al) or copper (Cu) is mounted on the host processor 18 and the electronic components 52.

[0059] <Configuration of the heat sink 56>

[0060] Figure 4 is Figure 3Enlarged view of part A, showing the relative positional relationship between the touch sensor 14 and the heat dissipation plate 56. In the following description, regarding the plurality of first electrodes 21, identification numbers are sequentially assigned from the left side as #1, #2, #3, #4 for distinction. In addition, for the convenience of illustration, only the first electrodes 21 among the plurality of electrodes 20 constituting the touch sensor 14 are shown, and the second electrodes 22 are omitted.

[0061] Figure 4 The dashed line shown in the lower top view corresponds to the contour line 60 of the rectangular heat dissipation plate 56. If the outermost point in the X direction on the contour line 60 is set as the "endpoint 62", then the endpoint 62 is located on the first electrode 21 of "#2". Hereinafter, the first electrode 21 overlapping with the position of the endpoint 62 is referred to as the "end-side electrode 64". In this case, the first electrode 21 of "#1" is located outside the end-side electrode 64, while the first electrodes 21 of "#3, #4" are located inside the end-side electrode 64.

[0062] Figure 4 The upper coordinate diagram shows the correspondence between the X coordinate (unit: mm) and the overlapping area S (unit: mm 2 )). This "overlapping area S" corresponds to the area of the overlapping part between each first electrode 21 and the heat dissipation plate 56. As understood from this coordinate diagram, the overlapping area S at "#1" becomes the minimum value (=0), and the overlapping areas at "#3, #4" become the maximum values. Here, note that the overlapping area S at "#2" is a value between the maximum value and the minimum value (that is, the intermediate value).

[0063] Figure 5 is Figure 3 Enlarged view of part B, showing the relative positional relationship between the first electrode 21, the second electrode 22, and the heat dissipation plate 56 in the vicinity of the endpoint 62. For the convenience of illustration, only one first electrode 21 and one second electrode 22 are shown.

[0064] The heat dissipation plate 56 is arranged such that its long side is parallel to the X direction and its short side is parallel to the Y direction. In this case, the endpoint 62 is the outermost point in the X direction on the contour line 60 and is also the outermost point in the Y direction. And this endpoint 62 is located on the intersection area 68 where one electrode (that is, the end-side electrode 64) among the plurality of first electrodes 21 and one electrode (that is, the end-side electrode 66) among the plurality of second electrodes 22 intersect.

[0065] It should be noted that the arrangement or shape of the heat dissipation plate 56 is not limited to Figure 4 and Figure 5 shown in the example. For example, as Figure 6AAs shown, the heat dissipation plate 56 can also be arranged in a state inclined with respect to the sensor area As of the touch sensor 14. In addition, as Figure 6B shown, the contour line 60 of the heat dissipation plate 56 may include not only a linear component but also a curved component.

[0066] <Functions and Effects of the Electronic Device 10>

[0067] The electronic device 10 in the first embodiment is configured as described above. Next, regarding the functions and effects of the electronic device 10, while referring to Figure 7 and Figure 8 it will be described.

[0068] Figure 7 is a diagram showing a comparative example corresponding to Figure 4 as an example, and shows the relative positional relationship between the touch sensor 14 and the heat dissipation plate 56. As understood from the Figure 7 top view from below, the end point 62 on the contour line 60 is located in the gap between the first electrodes 21 of "#2, #3". In this case, as Figure 7 shown in the coordinate diagram on the upper side, the overlapping area S at "#1, #2" becomes the minimum value (=0), and the overlapping area S at "#3, #4" becomes the maximum value. Here, note that the overlapping area S changes rapidly in the interval of "#1, #2".

[0069] Figure 8 is a diagram showing the effects achieved by the Figure 4 configuration relationship. The horizontal axis of the coordinate diagram represents the X coordinate (unit: mm), and the vertical axis of the coordinate diagram represents the detection value obtained by the MCU 38 (unit: none). Here, it is assumed that the electronic pen 12 is in a "hover state" where it is not in contact with the touch surface ( Figure 2 the protection panel 48) of the electronic device 10.

[0070] As understood from the comparative example (dashed coordinate diagram), peaks of the detection value are generated at the positions at both ends of the heat dissipation plate 56, respectively. It is considered that the reason is that: since Figure 7 the overlapping area S shown changes rapidly in the interval of "#2, #3", a difference is generated in the magnitude of the common-mode noise in which the signals of the positive-side electrode and the negative-side electrode are mixed, and this difference is amplified by the differential amplifier 30 ( Figure 1 ).

[0071] On the other hand, as understood from the example (solid coordinate diagram), the height of the peaks generated at the positions at both ends of the heat dissipation plate 56 is significantly suppressed. It is considered that the reason is that: through Figure 4The overlapping area S shown takes the middle value in the interval of "#2". The sharp change in the overlapping area S is mitigated compared to the case of the comparative example, and the difference in the magnitude of the above-mentioned common-mode noise becomes relatively smaller.

[0072] In particular, by arranging the heat dissipation plate 56 such that the length of the contour line 60 overlapping with the end-side electrode 64 ( Figure 4 the portion indicated by the thick dashed line below) is 10 mm or more, the above-mentioned mitigation effect of the change appears more significantly. In addition, the end point 62 is preferably located at a position close to the center line of the end-side electrodes 64 and 66 (for example, within the range of ±W / 4 from the center line if the width of the end-side electrodes 64 and 66 is defined as W).

[0073] It should be noted that the conductive component, in addition to the above-mentioned heat dissipation plate 56 and heat conduction path, may also be various electronic components 52 arranged on the main substrate 42 ( Figure 3 ), or a module independent of the main substrate 42 (for example, a battery pack). In particular, considering that the possibility of electromagnetic interference with the touch sensor 14 increases as the contour line 60 becomes longer, the conductive component is preferably a component with a relatively large occupied area, such as the heat dissipation plate 56, the heat conduction path, or the battery pack.

[0074] As described above, the electronic device 10 includes: a touch sensor 14 configured to include a plurality of electrodes 20 that are separated from each other along the arrangement direction and are arranged in a planar manner; a differential amplifier 30 that amplifies and outputs the difference between the positive-side signal and the negative-side signal selectively output from the plurality of electrodes 20; an MCU 38 (position detection unit) that detects the touch position within the sensor area As formed by the touch sensor 14 based on the output signal from the differential amplifier 30; and a conductive component (here, the heat dissipation plate 56), which is a component made of or including a conductive material and is arranged so as to partially overlap the sensor area As in a top view. And the heat dissipation plate 56 is arranged such that the outermost end point 62 in the arrangement direction is located on any one of the plurality of electrodes 20.

[0075] In this way, since the outermost end point 62 in the arrangement direction is configured to be located on any one of the plurality of electrodes 20, it is possible to mitigate the situation where the overlapping area S, which is the area of the overlapping portion between each first electrode 21 and the heat dissipation plate 56, changes sharply along the arrangement direction, and it is possible to reduce the difference in the magnitude of the common-mode noise mixed into the signals of the positive-side electrode and the negative-side electrode. Thereby, considering the relationship with the heat dissipation plate 56 that may be a noise generation source and further exerting the noise cancellation effect of the differential amplification method.

[0076] Alternatively, it may be that multiple electrodes 20 include multiple first electrodes 21 arranged separately from each other along the X direction (the first direction) and multiple second electrodes 22 arranged separately from each other along the Y direction (the second direction) that intersects the X direction. The heat dissipation plate 56 is arranged such that the end point 62 is located on the intersection region 68 where any one of the multiple first electrodes 21 and the multiple second electrodes 22 (the end-side electrodes 64, 66) intersects. Thus, the above-described noise cancellation effect is exerted simultaneously with respect to both the first electrode 21 and the second electrode 22.

[0077] [Second Embodiment]

[0078] Next, regarding the electronic device 100 in the second embodiment, an explanation will be given while referring Figures 9 - 16B thereto. Note that, regarding the same structures or functions as those in the first embodiment, the same reference numerals may be used and their descriptions may be omitted.

[0079] <Device Structure of Electronic Device 100>

[0080] Figure 9 This is a circuit structure diagram related to the position detection function of the electronic device 100 in the second embodiment of the present invention. The electronic device 100 is the same as in the case of the first embodiment ( Figure 1 the electronic device 10), and is constituted by, for example, a flat panel terminal, a smart phone, or a personal computer.

[0081] Specifically, the electronic device 100 is configured to include a touch sensor 102 having a structure different from that in the case of the first embodiment ( Figure 1 the touch sensor 14), a touch IC 104 for controlling the touch sensor 102, and a host processor 18 electrically connected to the touch IC 104. Here, the touch sensor 102 and the touch IC 104 correspond to the position detection device 106 that detects the touch position of the electronic device 100.

[0082] The touch sensor 102 is a capacitive type (specifically, a mutual capacitance type or a self-capacitance type) sensor that is overlapped and arranged on the display panel 130 ( Figure 10 ). The touch sensor 102 is configured to include multiple electrodes 110 that are arranged separately from each other along the arrangement direction and are arranged in a planar manner. The material of the electrodes 110 may be indium tin oxide (ITO), but is assumed to be a metal such as copper, silver, or gold here.

[0083] The P direction and the Q direction shown in this figure correspond to the P axis and the Q axis of the "sensor coordinate system" defined within the sensor region As formed in the touch sensor 102. In this second embodiment, it is noted that the sensor coordinate system does not coincide with the "display coordinate system" defined within the display region formed in the display panel 130 ( Figure 10 [[ID=

[0084] The electrode 110 includes a first electrode 111 for detecting the position in the P direction (the second direction) and a second electrode 112 for detecting the position in the Q direction (the first direction). A plurality of first electrodes 111 are arranged to extend in the Q direction, and are separated from each other and arranged at equal intervals along the orthogonal direction of the Q direction (that is, the P direction). A plurality of second electrodes 112 are arranged to extend in the P direction, and are separated from each other and arranged at equal intervals along the orthogonal direction of the P direction (that is, the Q direction).

[0085] The touch IC 104 is configured to include a P selection circuit 114, a Q selection circuit 116, a switch 118, a BP filter 32, a detection circuit 34, an AD converter 36, and an MCU 120. It should be noted that a differential amplifier 30 ( Figure 1 ) can also be provided in the touch IC 104 in the same circuit structure as that of the first embodiment.

[0086] The P selection circuit 114 is a multiplexer connected to the plurality of first electrodes 111 respectively. The P selection circuit 114 selects one electrode from the plurality of first electrodes 111 according to an instruction signal from the MCU 120, and sequentially outputs a P signal from the selected electrode. The Q selection circuit 116 is a multiplexer connected to the plurality of second electrodes 112 respectively. The Q selection circuit 116 selects one electrode from the plurality of second electrodes 112 according to an instruction signal from the MCU 120, and sequentially outputs a Q signal from the selected electrode.

[0087] The switch 118 is connected to the output sides of the P selection circuit 114 and the Q selection circuit 116 respectively. The switch 118 selectively outputs either one of the signals according to an instruction signal from the MCU 120.

[0088] The MCU 120 is a device capable of processing the digital signal output from the AD converter 36 to detect the touch position in the sensor area As. The MCU 120 calculates the position in the sensor coordinate system by using the above-described pen detection function or touch detection function, and transforms it into the position in the display coordinate system (X-Y coordinate value) by performing coordinate transformation on the obtained P-Q coordinate values. This coordinate transformation is uniquely determined according to the relative positional relationship between the touch sensor 102 and the display panel 130. When both the sensor coordinate system and the display coordinate system are orthogonal coordinate systems, this coordinate transformation is a two-dimensional affine transformation that rotates by an angle θ [rad] (where 0 < θ < π / 2) around a fixed point.

[0089] <Device Structure of the Electronic Device 100>

[0090] Figure 10 is Figure 9Exploded perspective view of the electronic device 100 shown. The electronic device 100 is constructed in the same manner as the electronic device 10 in the first embodiment ( Figure 2 By sequentially overlapping the back cover 40, the main substrate 42, the display panel 130, the touch sensor 102, and the front cover 46 from the back side. Similar to the first embodiment, the touch sensor 102 can be an externally mounted sensor or an in-cell type (on-cell type or in-cell type) sensor.

[0091] The display panel 130 is composed of, for example, a liquid crystal panel, an organic EL panel, an electronic paper, etc. The display panel 130 drives a plurality of pixels 134 by applying a driving voltage to a matrix-shaped signal line arranged in the row direction and the column direction, thereby displaying an image or video in the display area.

[0092] Figure 11 It is a diagram showing Figure 10 The structure of the driving circuit 132 included in the display panel 130. The driving circuit 132 is configured to include a matrix-shaped signal line arranged in the row direction and the column direction and a plurality of pixels 134 corresponding to the intersection of the matrix. The matrix-shaped signal line is composed of a plurality of source signal lines 136 extending in the Y direction and arranged at equal intervals in the X direction and a plurality of gate signal lines 138 extending in the X direction and arranged at equal intervals in the Y direction.

[0093] Each pixel 134 is configured to include a thin film transistor (Thin Film Transistor; hereinafter, TFT 140) and a pixel electrode 142. A source signal line 136 corresponding to the pixel 134 is connected to the source terminal of the TFT 140. A gate signal line 138 corresponding to the pixel 134 is connected to the gate terminal of the TFT 140. A pixel electrode 142 corresponding to the pixel 134 is connected to the drain terminal of the TFT 140.

[0094] The driving circuit 132 performs display driving of the display panel 130 by the "frame inversion method" of applying an AC driving voltage to the matrix-shaped signal line. For example, in Figure 12A In the "row line inversion method", the driving circuit 132 applies a driving voltage to the plurality of gate signal lines 138 in an alternating positive and negative manner. On the other hand, in Figure 12B In the "column line inversion method", the driving circuit 132 applies a driving voltage to the plurality of source signal lines 136 in an alternating positive and negative manner.

[0095] <Structure of the touch sensor 102>

[0096] Figure 13 It is Figure 9Partial enlarged view of the first electrode 111 shown. Each first electrode 111 is composed of metal fine wires 152 and 154 of a mesh structure formed by arranging meshes 150 of the same shape without gaps in the Q direction. One metal fine wire 152 is arranged to extend along the P direction, and the other metal fine wire 154 is arranged to extend along a direction intersecting the P direction (the intersection angle is 2θ). As can be understood from this figure, by being surrounded by two adjacent metal fine wires 152 and 154 each, a rhombus-shaped mesh 150 with an interior angle of 2θ [rad] is formed. It should be noted that the shape of the mesh 150 may also be other quadrilaterals other than the above rhombus, or may also be a polygon (so-called polygon) including triangles, hexagons, etc.

[0097] In addition, although not shown in the figure, each second electrode 112 ( Figure 9 ) is composed of metal fine wires 152 and 154 of a mesh structure formed by arranging meshes 150 of the same shape without gaps in the P direction. That is to say, the second electrode 112 has substantially the same shape as the first electrode 111 and is arranged along a direction different from that of the first electrode 111.

[0098] Figure 14 is Figure 9 and Figure 10 Top view of the touch sensor 102 shown. In addition to the above-mentioned rectangular sensor area As, the touch sensor 102 also includes a border area Ab and a converging area Aa.

[0099] The border area Ab is a frame-shaped area surrounding the entire peripheral part of the sensor area As. Lead wires 156 are arranged at one end of each of the plurality of electrodes 110 in the border area Ab. The lead wire 156 is a signal wire for electrically connecting the touch sensor 102 and the touch IC 104 (in the example of Figure 9 is the P selection circuit 114 and the Q selection circuit 116). It should be noted that the part shown by dot patterns in the border area Ab corresponds to the part where the lead wire 156 of the first electrode 111 is arranged. On the other hand, the part shown by the hatching of vertical lines in the border area Ab corresponds to the part where the lead wire 156 of the second electrode 112 is arranged.

[0100] The converging area Aa is a strip-shaped area corresponding to the FPC substrate 54 ( Figure 10 ). A plurality of lead wires 156 are arranged in the converging area Aa in a separated and parallel manner. In the example of this figure, the converging area Aa is provided at the lower left corner of the sensor area As, but it may also be provided at other parts (for example, the center of the long side, the center of the short side, etc.) instead.

[0101] <The first effect>

[0102] The electronic device 100 in the second embodiment is configured as described above. Figures 1 - 16B While explaining.

[0103] Figure 15A and Figure 15B It is shown by Figure 14 FIG. 1 is a diagram of a first effect achieved by the touch sensor 102. Specifically, Figure 15A "Comparative Example" is shown. Figure 15B For the convenience of illustration, one first electrode 21 (111), one second electrode 22 (112), one source signal line 136, and one gate signal line 138 are shown.

[0104] exist Figure 15A In the figure, the touch sensor 14 of the first embodiment is used, that is, the X direction is aligned with the P direction, and the Y direction is aligned with the Q direction. In this case, the first electrode 21 and the source signal line 136 tend to be parallel to each other. Therefore, due to electromagnetic interference with the source signal line 136, common-mode noise is easily mixed into the detection signal of the touch sensor 14. It should be noted that the same tendency as described above can also be seen in the relationship between the second electrode 22 and the gate signal line 138.

[0105] exist Figure 15B In the figure, the touch sensor 102 of the second embodiment is used, that is, the X direction and the P direction do not align, and the Y direction and the Q direction do not align. In this case, the first electrode 111 and the source signal line 136 are always in a "twisted position," so electromagnetic interference with the source signal line 136 is less likely to occur, and the incorporation of common-mode noise into the detection signal of the touch sensor 14 is suppressed. It should be noted that the same tendency as described above can also be observed in the relationship between the second electrode 112 and the gate signal line 138.

[0106] As described above, the touch sensor 102 is a sensor used together with the display panel 130. The display panel 130 drives a plurality of pixels 134 by applying a driving voltage to matrix-shaped signal lines (source signal lines 136 and gate signal lines 138) arranged in the X direction (row direction) and the Y direction (column direction), and can display an image or video in the display area. The touch sensor 102 is arranged so as to at least partially overlap the display area in a top view, and is configured to include a plurality of electrodes 110 arranged in a rectangular shape. The plurality of electrodes 110 include a plurality of first electrodes 111 extending in the Q direction (first direction) and arranged separately from each other along the orthogonal direction thereof, and a plurality of second electrodes 112 extending in the P direction (second direction) intersecting the Q direction and arranged separately from each other along the orthogonal direction thereof. At least one of the P direction and the Q direction is inclined with respect to both the X direction and the Y direction.

[0107] Thus, since at least one of the Q direction in which the first electrode 111 extends and the P direction in which the second electrode 112 extends is inclined with respect to both the X direction and the Y direction, the relationship of "twisted position" can be always maintained between the electrode 110 and the matrix-shaped signal lines, and the mixing of common-mode noise caused by the electronic interference with the display panel 130 into the detection signal of the touch sensor 102 can be suppressed.

[0108] In particular, in the case where an image or video of each frame is displayed on the display panel 130 by the "row line inversion method" (refer to Figure 12A ) in which the driving voltage is alternately inverted between positive and negative with respect to the gate signal line 138 extending in the X direction, the P direction and the Q direction are preferably inclined with respect to the X direction, respectively. By making the sign of the driving voltage with respect to the gate signal line 138 change periodically with space and time, the generation of common-mode noise is further suppressed.

[0109] Similarly, in the case where an image or video of each frame is displayed on the display panel 130 by the "column line inversion method" (refer to Figure 12B ) in which the driving voltage is alternately inverted between positive and negative with respect to the source signal line 136 extending in the Y direction, the P direction and the Q direction are preferably inclined with respect to the Y direction, respectively. By making the sign of the driving voltage with respect to the source signal line 136 change periodically with space and time, the generation of common-mode noise is further suppressed.

[0110] <Second effect>

[0111] According to the touch sensor 102, an effect independent of the above-described suppression effect of common-mode noise can also be obtained. Hereinafter, the second effect achieved by the touch sensor 102 will be described with reference to Figure 16A and Figure 16B while. Figure 16AShows a "comparative example" using the touch sensor 14 of the first embodiment, and Figure 16B shows an "embodiment" using the touch sensor 102 of the second embodiment.

[0112] For example, consider a case where the converging area Aa is provided at the lower left corner of the sensor area As and the wiring layout at the second electrodes 22, 112 closest to the upper long side is designed. For example, in Figure 16A the "comparative example", the wiring is done in a way that passes through the upper right corner, upper left corner, and lower left corner of the sensor area As. Therefore, the wiring length L1 at a specific electrode 20 becomes relatively long, and the resistance will increase accordingly. In contrast, in Figure 16B the "embodiment", the wiring is done in a way that passes through the upper right corner, lower center, and lower left corner of the sensor area As. Therefore, the wiring length L2 at a specific electrode 110 becomes relatively short, and the resistance decreases accordingly.

[0113] In this way, when the touch sensor 102 and the MCU 120 are connected by a plurality of lead wires 156, the lead wires 156 can also be provided at the end on the side closer to the MCU 120 on the electrodes 110 that straddle two adjacent sides (that is, the long side and the short side) of the sensor area As. Thus, compared with the case of wiring along the periphery of the sensor area As, it is easy to shorten the wiring length at a specific electrode 110.

[0114] In addition, in this touch sensor 102, in addition to the electrodes 110 that straddle two adjacent sides, there may also be electrodes 110 that straddle two opposite sides (that is, long sides or short sides). Accordingly, the options related to on which side to provide the lead wires 156 increase. As a result, another effect can be obtained that the degree of freedom in design related to the arrangement of the lead wires 156 is higher compared to the touch sensor 14 of the first embodiment ( Figure 1 ).

[0115] [Reference Signs Explanation]

[0116] 10, 100... electronic devices, 12... electronic pen, 14, 102... touch sensors, 16... touch IC, 20, 110... electrodes, 21, 111... first electrodes, 22, 112... second electrodes, 30... differential amplifier, 38... MCU (position detection unit), 44, 130... display panels, 56... heat sink (conductive component), 60... contour line, 62... end point, 64, 66... end side electrodes, 68... crossing area, 104... touch IC (position detection unit), 106... position detection device, 134... pixel, 136... source signal line, 138... gate signal line, 150... mesh, 152, 154... metal fine wires, 156... lead wire, Aa... converging area, Ab... border area, As... sensor area.

Claims

1. A touch sensor, which is used together with a display panel. The display panel drives a plurality of pixels by applying a driving voltage to a matrix-shaped signal line arranged in a row direction and a column direction, so that an image or video can be displayed in a display area. The touch sensor is characterized in that it is arranged in a manner that at least partially overlaps with the display area when viewed from above, it is configured to include a plurality of electrodes arranged in a rectangular shape, the plurality of electrodes include: a plurality of first electrodes, which are arranged to extend in a first direction and are separated from each other along an orthogonal direction of the first direction; and a plurality of second electrodes, which are arranged to extend in a second direction intersecting with the first direction and are separated from each other along an orthogonal direction of the second direction, at least one of the first direction and the second direction is inclined with respect to both the row direction and the column direction, the first direction is orthogonal to the second direction, in the case where the display panel displays an image or video of each frame by a line inversion method in which a driving voltage is applied to the signal line extending in the row direction in an alternating positive and negative manner, the first direction and the second direction are respectively inclined with respect to the row direction, in the case where the display panel displays an image or video of each frame by a line inversion method in which a driving voltage is applied to the signal line extending in the column direction in an alternating positive and negative manner, the first direction and the second direction are respectively inclined with respect to the column direction.

2. The touch sensor according to claim 1, characterized in that each of the plurality of first electrodes is composed of a fine metal wire of a mesh structure formed by arranging meshes of the same shape without gaps in the second direction, each of the plurality of second electrodes is composed of a fine metal wire of a mesh structure formed by arranging meshes of the same shape without gaps in the first direction.

3. A position detection device, characterized in that, It includes: the touch sensor according to claim 1 or 2; and a position detection unit, which detects a touch position in a sensor area formed by the touch sensor based on a detection signal from the touch sensor.

4. The position detection device according to claim 3, characterized in that the touch sensor and the position detection unit are connected by a plurality of lead wires provided at one end of each of the plurality of electrodes, the lead wires are provided at an end on a side close to the position detection unit on electrodes across two adjacent sides of the sensor area.

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