Touch sensor and position detection device

Abstract

To provide a touch sensor and a position detection apparatus capable of suppressing mixing of common mode noise in a detection signal, which is caused by electronic interference with a display panel.SOLUTION: A touch sensor 102 includes a plurality of electrodes 110 arranged in a rectangular shape so as to partially overlap a display region in plan view. The electrodes 110 includes: a plurality of linear or band-like first electrodes 111 extending in a Q direction (first direction) and separated from each other in an orthogonal direction with respect to the Q direction; and a plurality of linear or band-like second electrodes 112 extending in a P direction (second direction) intersecting with the Q direction and separated from each other in an orthogonal direction with respect to the P direction. At least one of the P and Q directions is inclined with respect to both an X-direction (row direction) and a Y-direction (column direction) of a display panel (130).SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a touch sensor and a position detection device. [Background technology]

[0002] Patent Document 1 discloses a position detection device that uses a so-called "differential amplification method," which amplifies and outputs the difference between the signal from the positive electrode and the signal from the negative electrode of a touch sensor. By taking the difference between the signals from two parallel electrodes, it is possible to cancel out common mode noise that occurs in the same direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-095701 Summary of the Invention [Problem to be solved by the invention]

[0004] In addition to the touch sensor, electronic devices also contain components made of or including conductive materials (hereinafter referred to as conductive components). Electromagnetic interference with these conductive components can cause common-mode noise to be mixed into the detection signal of the touch sensor. Typically, these conductive components are smaller than the sensor area of ​​the touch sensor and are positioned so as to partially overlap the sensor area in a plan view. Therefore, the magnitude of noise contained in the detection signal may vary depending on the position within the sensor area.

[0005] However, in a differential amplification method such as that described in Patent Document 1, if the magnitude of the noise mixed into the signal from the positive electrode and the signal from the negative electrode differs, the effect of canceling out the common-mode noise cannot be obtained, and the effect of the noise becomes even greater due to amplification.

[0006] An object of the present invention is to provide an electronic device that can effectively cancel out noise using a differential amplification method, while taking into consideration the relationship with conductive parts that can be sources of noise. [Means for solving the problem]

[0007] The electronic device of the first invention comprises a touch sensor including a plurality of electrodes arranged in a plane along an arrangement direction and spaced apart from each other, a differential amplifier that amplifies and outputs the difference between a positive signal and a negative signal selectively output from the plurality of electrodes, a position detection unit that detects a touch position within a sensor area formed by the touch sensor based on the output signal from the differential amplifier, and a conductive component made of or including a conductive material and arranged so as to partially overlap the sensor area in a planar view, wherein the conductive component is arranged so that its outermost end point in the arrangement direction is located on any one of the plurality of electrodes.

[0008] The touch sensor of the second invention is a sensor used in conjunction with a display panel that can display an image or video within a display area by applying a driving voltage to a matrix of signal lines arranged in row and column directions to drive a plurality of pixels, and is configured to include a plurality of electrodes arranged in a rectangular shape so as to at least partially overlap the display area in a planar view, the plurality of electrodes including a plurality of first electrodes having a linear or strip-like outer shape extending in a first direction and arranged at a distance from each other along a direction perpendicular to the first direction, and a plurality of second electrodes having a linear or strip-like outer shape extending in a second direction intersecting the first direction and arranged at a distance from each other along a direction perpendicular 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.

[0009] A position detection device according to a third aspect of the present invention includes the touch sensor according to the second aspect of the present invention, and a position detection section that detects a touch position within a sensor area defined by the touch sensor based on a detection signal from the touch sensor. [Effects of the Invention]

[0010] According to the first aspect of the present invention, it is possible to further exert the effect of canceling out noise by the differential amplification method while taking into consideration the relationship with conductive parts that may be sources of noise. According to the second and third aspects of the present invention, it is possible to prevent common mode noise caused by electronic interference with the display panel from being mixed into the detection signal of the touch sensor. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a circuit configuration diagram relating to a position detection function of an electronic device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an exploded perspective view of the electronic device shown in FIG. [Figure 3] 3 is a diagram showing the relative positional relationship between the main substrate, the display panel, and the touch sensor shown in FIG. 2. FIG. [Figure 4] FIG. 4 is an enlarged view of part A in FIG. 3. [Figure 5] FIG. 4 is an enlarged view of part B in FIG. 3. [Figure 6A] 5 is a diagram showing another configuration of the heat sink of FIG. 4. FIG. [Figure 6B] 5 is a diagram showing another configuration of the heat sink of FIG. 4. FIG. [Figure 7] FIG. 5 is a diagram showing a comparative example corresponding to FIG. 4. [Figure 8] 5 is a diagram illustrating the effect of the arrangement relationship in FIG. 4. FIG. [Figure 9] FIG. 10 is a circuit configuration diagram relating to a position detection function of an electronic device according to a second embodiment of the present invention. [Figure 10] FIG. 10 is an exploded perspective view of the electronic device shown in FIG. [Figure 11] 11 is a diagram showing the structure of a drive circuit included in the display panel of FIG. [Figure 12A] FIG. 1 is a schematic diagram relating to a line inversion driving method. [Figure 12B] FIG. 1 is a schematic diagram relating to a line inversion driving method. [Figure 13]FIG. 10 is a partially enlarged view of the first electrode shown in FIG. [Figure 14] FIG. 11 is a plan view of the touch sensor shown in FIGS. 9 and 10. [Figure 15A] FIG. 15 is a diagram showing a comparative example for explaining a first effect of the touch sensor of FIG. [Figure 15B] 15A and 15B are diagrams illustrating an example for explaining a first effect of the touch sensor of FIG. 14. FIG. [Figure 16A] FIG. 15 is a diagram showing a comparative example for explaining a second effect of the touch sensor of FIG. [Figure 16B] 15A and 15B are diagrams illustrating an example for explaining a second effect of the touch sensor of FIG. 14. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, preferred embodiments of the electronic device, touch sensor, and position detection device of the present invention will be described with reference to the accompanying drawings. Note that the present invention is not limited to the following embodiments and modifications, and can be freely modified without departing from the spirit of the present invention. Alternatively, the respective configurations may be arbitrarily combined within the scope of no technical contradiction.

[0013] [First embodiment] An electronic device according to a first embodiment of the present invention will be described below with reference to FIGS.

[0014] <Circuit configuration of electronic device 10> FIG. 1 is a circuit configuration diagram relating to the position detection function of an electronic device 10 according to a first embodiment of the present invention. The electronic device 10 may be, for example, a tablet terminal, a smartphone, or a personal computer. A user can write pictures or characters on the electronic device 10 by holding an electronic pen 12 and moving the pen tip against the touch surface of the electronic device 10 while pressing it against the touch surface. The electronic pen 12 is, for example, an active electrostatic (AES) or electromagnetic induction (EMR) stylus.

[0015] Specifically, the electronic device 10 includes a touch sensor 14 that detects the approach of a conductive object such as an electronic pen 12 or a 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.

[0016] The touch sensor 14 is a capacitance sensor that is disposed over the display panel 44 (FIG. 2). The touch sensor 14 may be a mutual capacitance sensor or a self-capacitance sensor. The touch sensor 14 is configured to include a plurality of electrodes 20 that are arranged in a plane and spaced apart from each other along the arrangement direction. The material of the electrodes 20 may be indium tin oxide (ITO) or a metal such as copper, silver, or gold.

[0017] The linear or strip-shaped electrode 20 includes a first electrode 21 for detecting a position in the X direction (X coordinate) and a second electrode 22 for detecting a position in the Y direction (Y coordinate). The first electrode 21 and the second electrode 22 are insulated from each other by an insulating substrate (not shown) made of glass or resin. The first electrodes 21 extend in the Y direction and are spaced apart from each other at equal intervals along the X direction. The second electrodes 22 extend in the X direction and are spaced apart from each other at equal intervals along the Y direction. That is, the X and Y directions shown in this figure correspond to the X and Y axes of a "sensor coordinate system" defined within the sensor area As formed by the touch sensor 14. In this first embodiment, the sensor coordinate system coincides with a "display coordinate system" defined within the display area formed by the display panel 44 (FIG. 2).

[0018] The touch IC 16 includes 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 a BP filter 32), a detection circuit 34, an AD converter 36, and a microcontroller unit (hereinafter referred to as an MCU 38).

[0019] The X selection circuits 24 are multiplexers connected to the plurality of first electrodes 21, respectively. The X selection circuits 24 select two electrodes from the plurality of first electrodes 21 in response to a command signal from the MCU 38, and simultaneously output two types of signals (an X positive signal and an X negative signal) from each electrode. The Y selection circuits 26 are multiplexers connected to the plurality of second electrodes 22, respectively. The Y selection circuits 26 select two electrodes from the plurality of second electrodes 22 in response to a command signal from the MCU 38, and simultaneously output two types of signals (a Y positive signal and a Y negative signal) from each electrode.

[0020] The switches 28 are connected to the output sides of the X selection circuit 24 and the Y selection circuit 26. The switches 28 selectively output either the positive signal or the negative signal in response to a command signal from the MCU 38. The differential amplifier 30 amplifies the difference between the positive signal and the negative signal selectively output from the multiple electrodes 20 via the switches 28 and outputs the amplified difference.

[0021] The BP filter 32 is a filter circuit that passes a predetermined bandwidth centered on a frequency corresponding to the output signal from the electronic pen 12. The detection circuit 34 is a circuit that generates a detection signal from 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.

[0022] The MCU 38 is a device capable of processing the digital signal output from the AD converter 36 and detecting the touch position within the sensor area As. The MCU 38 reads and executes a position detection program from a memory (not shown) to perform a "pen detection function" that detects the state of the electronic pen 12 and a "touch detection function" that detects a touch by the user's finger or the like.

[0023] The pen detection function includes, for example, a function of scanning the touch sensor 14 (global scan or sector scan), a function of receiving and analyzing downlink signals, a function of estimating the state of the electronic pen 12 (for example, position, posture, and writing pressure), and a function of generating and transmitting uplink signals including commands to the electronic pen 12. In addition, the touch detection function includes, for example, a function of scanning the touch sensor 14, a function of creating a detection map (two-dimensional distribution of detection levels) within the sensor area As, and a function of classifying areas on the detection map (for example, classification into fingers, palm, etc.).

[0024] The host processor 18 is configured with 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 generating digital ink, creating image signals, and controlling the transmission and reception of data, by reading and executing programs stored in a memory (not shown).

[0025] <Device configuration of electronic device 10> 2 is an exploded perspective view of the electronic device 10 shown in FIG. 1. FIG. 3 is a diagram showing the relative positional relationship between the main board 42, the display panel 44, and the touch sensor 14 shown in FIG. 2. The electronic device 10 is configured by stacking, in order from the rear side, a rear cover 40, the main board 42, the display panel 44, the touch sensor 14, and a front cover 46. In the example shown in this figure, the touch sensor 14 is an "external type" sensor that is attached to the display panel 44 from the outside, but instead it may be an "internal type" sensor (further classified as an on-cell type or an in-cell type) that is configured integrally with the display panel 44.

[0026] The rear cover 40 and the front cover 46 are members that form a housing that houses electronic components within the electronic device 10. The front cover 46 is provided with a highly translucent protective panel 48 that covers the entire opening formed on its main surface.

[0027] The display panel 44 is configured by, for example, a liquid crystal panel, an organic EL (Electro Luminescence) panel, electronic paper, etc. The display panel 44 displays an image or video within a display area by applying a driving voltage to a matrix of signal lines arranged in row and column directions to drive a plurality of pixels.

[0028] The main board 42 is a board that forms an electric circuit for operating the electronic device 10. As shown in Fig. 3, in addition to the above-mentioned touch IC 16 and host processor 18, a connector 50 and various electronic components 52 are arranged on the main board 42. The connector 50 is configured to be able to electrically connect the touch IC 16 to a flexible printed circuit board (hereinafter referred to as FPC board 54) provided at the end of the touch sensor 14. Examples of the electronic components 52 include a drive IC for the display panel 44, a memory, a wireless communication module, a power supply circuit, and an electronic element (e.g., a coil).

[0029] Incidentally, electronic components, including processors, may experience a decrease in processing performance or malfunction due to an increase in internal or ambient temperature. To prevent this phenomenon, the electronic device 10 may be provided with a heat sink or a heat conduction path to dissipate heat generated within the device. In the example shown in the figure, a heat sink 56 (conductive component) containing a conductive material such as aluminum (Al) or copper (Cu) is attached to the host processor 18 and electronic components 52.

[0030] <Arrangement of heat sink 56> 4 is an enlarged view of portion A in FIG. 3, showing the relative positional relationship between the touch sensor 14 and the heat sink 56. In the following description, the multiple first electrodes 21 are identified by the identification numbers #1, #2, #3, and #4, starting from the left. For ease of illustration, only the first electrodes 21 of the multiple electrodes 20 constituting the touch sensor 14 are shown, and the second electrodes 22 are omitted.

[0031] The dashed line shown in the plan view at the bottom of Figure 4 corresponds to the contour line 60 of the rectangular heat sink 56. If the point on this contour line 60 that is located farthest out in the X direction is defined as an "end point 62," this end point 62 is located on the first electrode 21 of "#2." Hereinafter, the first electrode 21 that overlaps the position of the end point 62 will be referred to as the "end electrode 64." In this case, the first electrode 21 of "#1" is located outside the end electrode 64, while the first electrodes 21 of "#3, #4" are located inside the end electrode 64.

[0032] The graph at the top of Figure 4 shows the relationship between the X coordinate (unit: mm) and the overlap area S (unit: mm 2 ) shows the correspondence between the overlapping areas S. This "overlapping area S" corresponds to the area of ​​the overlapping portion between each first electrode 21 and heat sink 56. As can be seen from this graph, the overlapping area S at "#1" is the minimum value (=0), and the overlapping area at "#3, #4" is the maximum value. Note that the overlapping area S at "#2" is a value between the maximum and minimum values ​​(i.e., an intermediate value).

[0033] 5 is an enlarged view of part B in FIG. 3, and shows the relative positional relationship between the first electrode 21, the second electrode 22, and the heat sink 56 in the vicinity of the end point 62. For convenience of illustration, only one first electrode 21 and one second electrode 22 are shown.

[0034] The heat sink 56 is disposed so that its long sides are parallel to the X direction and its short sides are parallel to the Y direction. In this case, the end point 62 is the outermost point of the contour 60 in the X direction and also the outermost point in the Y direction. The end point 62 is located on an intersection region 68 where one of the plurality of first electrodes 21 (i.e., end electrode 64) and one of the plurality of second electrodes 22 (i.e., end electrode 66) intersect.

[0035] The arrangement or shape of the heat sink 56 is not limited to the examples shown in Figures 4 and 5. For example, as shown in Figure 6A, the heat sink 56 may be arranged in a state inclined with respect to the sensor area As of the touch sensor 14. Furthermore, as shown in Figure 6B, the contour line 60 of the heat sink 56 may include not only straight line components but also curved line components.

[0036] <Actions and effects of electronic device 10> The electronic device 10 according to the first embodiment is configured as described above. Next, the functions and effects of the electronic device 10 will be described with reference to FIGS.

[0037] FIG. 7 is a diagram showing a comparative example corresponding to FIG. 4 of the embodiment, and shows the relative positional relationship between the touch sensor 14 and the heat sink 56. As can be seen from the plan view in the lower part of FIG. 7, an 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 shown in the graph in the upper part of FIG. 7, the overlapping area S between "#1, #2" is the minimum value (=0), and the overlapping area S between "#3, #4" is the maximum value. Note that the overlapping area S changes abruptly in the section between "#1, #2."

[0038] Figure 8 is a diagram showing the effect of the arrangement relationship in Figure 4. The horizontal axis of the graph indicates the X coordinate (unit: mm), and the vertical axis of the graph indicates the detection value (unit: no) acquired by MCU 38. Here, it is assumed that electronic pen 12 is in a "hover state" where it is not in contact with the touch surface of electronic device 10 (protective panel 48 in Figure 2).

[0039] As can be seen from the comparative example (graph indicated by the dashed line), peaks of the detection value occur at both ends of the heat sink 56. The reason for this is thought to be that the overlapping area S shown in Fig. 7 changes suddenly in the section "#2, #3," which causes a difference in the magnitude of the common-mode noise mixed into the signal from the positive electrode and the signal from the negative electrode, and this difference is amplified by the differential amplifier 30 (Fig. 1).

[0040] On the other hand, as can be seen from the example (solid line graph), the height of the peaks occurring at both ends of the heat sink 56 is significantly suppressed. The reason for this is thought to be that the overlapping area S shown in Fig. 4 takes an intermediate value in the section "#2", which alleviates the sudden change in the overlapping area S compared to the comparative example, and the difference in the magnitude of the common mode noise described above becomes relatively smaller.

[0041] In particular, the effect of mitigating the above-mentioned changes is more pronounced by positioning the heat sink 56 so that the length of the contour line 60 overlapping the end electrode 64 (the portion indicated by the thick dashed line at the bottom of FIG. 4) is 10 mm or more. Also, it is preferable that the end point 62 is located close to the center line of the end electrodes 64, 66 (for example, within a range of ±W / 4 from the center line, where W is the width of the end electrodes 64, 66).

[0042] The conductive component may be the heat sink 56 or the heat conduction path described above, or may be any of various electronic components 52 arranged on the main board 42 (FIG. 3), or may be a module (e.g., a battery pack) separate from the main board 42. In particular, considering that the longer the contour line 60, the higher the possibility of causing electromagnetic interference with the touch sensor 14, the conductive component is preferably a component with a relatively large occupation area, such as the heat sink 56, the heat conduction path, or the battery pack.

[0043] As described above, electronic device 10 includes touch sensor 14 including a plurality of electrodes 20 spaced apart from one another and arranged in a plane along the arrangement direction, differential amplifier 30 amplifying and outputting the difference between positive and negative signals selectively output from the plurality of electrodes 20, MCU 38 (position detection unit) detecting a touch position within sensor area As formed by touch sensor 14 based on the output signal from differential amplifier 30, and a conductive component (heat sink 56 in this case) made of or including a conductive material and arranged so as to partially overlap sensor area As in a planar view. Heat sink 56 is arranged so that its outermost end point 62 in the arrangement direction is located on any one of the plurality of electrodes 20.

[0044] In this way, since the outermost end point 62 in the arrangement direction is configured to be located on any one of the multiple electrodes 20, it is possible to mitigate sudden changes in the overlapping area S, which is the area of ​​the overlapping portion between each first electrode 21 and heat sink 56, along the arrangement direction, and it is possible to reduce the difference in the magnitude of common mode noise mixed into the signal of the positive electrode and the signal of the negative electrode. This allows for a better noise cancellation effect using differential amplification, while taking into account the relationship with heat sink 56, which may be a noise source.

[0045] The plurality of electrodes 20 may include a plurality of first electrodes 21 arranged at a distance from one another along the X direction (first direction) and a plurality of second electrodes 22 arranged at a distance from one another along the Y direction (second direction) intersecting the X direction, and the heat sink 56 may be arranged so that its end point 62 is located on an intersection region 68 where one electrode (end electrodes 64, 66) of the plurality of first electrodes 21 intersects with one electrode of the plurality of second electrodes 22. This allows the above-mentioned noise cancellation effect to be exerted simultaneously on both the first electrodes 21 and the second electrodes 22.

[0046] [Second embodiment] Next, the electronic device 100 in the second embodiment will be described with reference to Figures 9 to 16B. Note that the same reference numerals are used for configurations or functions that are the same as those in the first embodiment, and descriptions thereof may be omitted.

[0047] <Device configuration of electronic device 100> 9 is a circuit configuration diagram relating to the position detection function of the electronic device 100 according to the second embodiment of the present invention. As in the first embodiment (electronic device 10 in FIG. 1), the electronic device 100 is configured as, for example, a tablet terminal, a smartphone, or a personal computer.

[0048] Specifically, the electronic device 100 includes a touch sensor 102 having a different configuration from that of the first embodiment (touch sensor 14 in FIG. 1), 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 a position detection device 106 that detects a touch position on the electronic device 100.

[0049] The touch sensor 102 is a capacitance type (specifically, a mutual capacitance type or a self-capacitance type) sensor that is arranged over the display panel 130 (FIG. 10). The touch sensor 102 is configured to include a plurality of electrodes 110 that are arranged in a plane and spaced apart from each other along the arrangement direction. The material of the electrodes 110 may be indium tin oxide (ITO), but in this example it is assumed to be a metal such as copper, silver, or gold.

[0050] The P and Q directions shown in this figure correspond to the P and Q axes of the "sensor coordinate system" defined within the sensor area As formed by the touch sensor 102. Note that in this second embodiment, the sensor coordinate system does not coincide with the "display coordinate system" defined within the display area formed by the display panel 130 (FIG. 10).

[0051] The electrode 110 includes a first electrode 111 for detecting a position in the P direction (second direction) and a second electrode 112 for detecting a position in the Q direction (first direction). The first electrodes 111 are provided to extend in the Q direction and are spaced apart at equal intervals along a direction orthogonal to the Q direction (i.e., the P direction). The second electrodes 112 are provided to extend in the P direction and are spaced apart at equal intervals along the direction orthogonal to the P direction (i.e., the Q direction).

[0052] The touch IC 104 includes 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. The touch IC 104 may be provided with a differential amplifier 30 (FIG. 1) similar to the circuit configuration of the first embodiment.

[0053] The P selection circuit 114 is a multiplexer connected to each of the plurality of first electrodes 111. The P selection circuit 114 selects one electrode from the plurality of first electrodes 111 in response to a command signal from the MCU 120, and sequentially outputs P signals from the selected electrode. The Q selection circuit 116 is a multiplexer connected to each of the plurality of second electrodes 112. The Q selection circuit 116 selects one electrode from the plurality of second electrodes 112 in response to a command signal from the MCU 120, and sequentially outputs Q signals from the selected electrode.

[0054] The switch 118 is connected to the output side of each of the P selection circuit 114 and the Q selection circuit 116. In response to a command signal from the MCU 120, the switch 118 selectively outputs one of the signals.

[0055] The MCU 120 is a device capable of processing the digital signal output from the AD converter 36 and detecting the touch position within the sensor area As. The MCU 120 calculates the position in the sensor coordinate system using the pen detection function or touch detection function described above, and converts the obtained PQ coordinate values ​​into positions (XY coordinate values) in the display coordinate system by performing coordinate transformation. This coordinate transformation is uniquely determined depending on the relative positional relationship between the touch sensor 102 and the display panel 130. When the sensor coordinate system and the display coordinate system are both Cartesian 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.

[0056] <Device configuration of electronic device 100> Fig. 10 is an exploded perspective view of the electronic device 100 shown in Fig. 9. As in the first embodiment (electronic device 10 in Fig. 2), this electronic device 100 is configured by stacking, from the rear side, a rear cover 40, a main board 42, a display panel 130, a touch sensor 102, and a front cover 46. As in the first embodiment, the touch sensor 102 may be an external sensor or a built-in sensor (on-cell type or in-cell type).

[0057] The display panel 130 is configured by, for example, a liquid crystal panel, an organic EL panel, electronic paper, etc. The display panel 130 displays an image or video within a display area by applying a driving voltage to a matrix of signal lines arranged in row and column directions to drive a plurality of pixels 134.

[0058] Fig. 11 is a diagram showing the structure of a drive circuit 132 included in the display panel 130 of Fig. 10. This drive circuit 132 is configured to include a matrix of signal lines arranged in the row and column directions, and a plurality of pixels 134 corresponding to the intersections of the matrix. The matrix of signal lines is made up 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.

[0059] Each pixel 134 includes a thin film transistor (hereinafter referred to as TFT 140) and a pixel electrode 142. A source terminal of the TFT 140 is connected to a source signal line 136 corresponding to the pixel 134. A gate terminal of the TFT 140 is connected to a gate signal line 138 corresponding to the pixel 134. A drain terminal of the TFT 140 is connected to a pixel electrode 142 corresponding to the pixel 134.

[0060] The drive circuit 132 drives the display panel 130 by a "frame inversion method" that applies an AC drive voltage to a matrix of signal lines. For example, in the "row line inversion method" of FIG. 12A, the drive circuit 132 applies drive voltages to a plurality of gate signal lines 138 in a staggered manner with the positive and negative polarities reversed. On the other hand, in the "column line inversion method" of FIG. 12B, the drive circuit 132 applies drive voltages to a plurality of source signal lines 136 in a staggered manner with the positive and negative polarities reversed.

[0061] <Configuration of touch sensor 102> 13 is a partially enlarged view of the first electrode 111 shown in FIG. 9. Each first electrode 111 is made of thin metal wires 152, 154 in a mesh structure in which meshes 150 of the same shape are arranged without gaps in the Q direction. One thin metal wire 152 is arranged to extend along the P direction, and the other thin metal wire 154 is arranged to extend along a direction intersecting the P direction (the intersection angle is 2θ). As can be seen from this figure, a diamond-shaped mesh 150 with one of its interior angles being 2θ [rad] is formed by being surrounded by two adjacent thin metal wires 152, 154. The shape of the mesh 150 may be a quadrangle other than the above-mentioned diamond, or may be a polygon (so-called polygon) including a triangle or hexagon.

[0062] Although not shown, each second electrode 112 (FIG. 9) is made of thin metal wires 152, 154 having a mesh structure in which meshes 150 of the same shape are arranged without gaps in the direction P. In other words, the second electrodes 112 have basically the same shape as the first electrodes 111, but are arranged along a different direction from the first electrodes 111.

[0063] Fig. 14 is a plan view of the touch sensor 102 shown in Fig. 9 and Fig. 10. The touch sensor 102 further includes a bezel area Ab and an aggregated area Aa in addition to the rectangular sensor area As described above.

[0064] The bezel area Ab is a frame-shaped area surrounding the entire periphery of the sensor area As. In the bezel area Ab, lead lines 156 are wired, each of which is provided at one end of a plurality of electrodes 110. These lead lines 156 are signal lines for electrically connecting the touch sensor 102 and the touch IC 104 (in the example of FIG. 9, the P selection circuit 114 and the Q selection circuit 116). The dotted areas in the bezel area Ab correspond to the locations where the lead lines 156 of the first electrodes 111 are wired. On the other hand, the vertically hatched areas in the bezel area Ab correspond to the locations where the lead lines 156 of the second electrodes 112 are wired.

[0065] The aggregation area Aa is a strip-shaped area corresponding to the FPC board 54 (FIG. 10). In the aggregation area Aa, a plurality of lead wires 156 are wired so as to be parallel and spaced apart from each other. In the example shown in the figure, the aggregation area Aa is provided in the lower left corner of the sensor area As, but it may instead be provided in another location (for example, the center of the long side or the center of the short side).

[0066] <First effect> The electronic device 100 according to the second embodiment is configured as described above. Next, the functions and effects of the electronic device 100 will be described with reference to FIGS. 1A to 16B.

[0067] 15A and 15B are diagrams showing the first effect of the touch sensor 102 of Fig. 14. Specifically, Fig. 15A shows a "comparison example," and Fig. 15B shows an "embodiment." For convenience of illustration, the first electrode 21 (111), the second electrode 22 (112), the source signal line 136, and the gate signal line 138 are shown one by one.

[0068] 15A assumes the case where 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 electrodes 21 and the source signal lines 136 tend to be parallel to each other. This causes electromagnetic interference with the source signal lines 136, which makes it easier for common mode noise to be mixed into the detection signal of the touch sensor 14. Note that the same tendency as above is also seen in the relationship between the second electrodes 22 and the gate signal lines 138.

[0069] 15B assumes the case where the touch sensor 102 of the second embodiment is used, that is, the case where the X direction does not coincide with the P direction and the Y direction does not coincide with the Q direction. In this case, the first electrode 111 and the source signal line 136 are always in a "twisted position" relationship, which makes it difficult for electromagnetic interference with the source signal line 136 to occur and suppresses the inclusion of common mode noise in the detection signal of the touch sensor 14. Note that the same tendency as above is also seen in the relationship between the second electrode 112 and the gate signal line 138.

[0070] As described above, the touch sensor 102 is a sensor used in conjunction with a display panel 130 that can display an image or video within a display area by applying a drive voltage to a matrix of signal lines (source signal lines 136, gate signal lines 138) arranged in the X direction (row direction) and the Y direction (column direction) to drive a plurality of pixels 134. The touch sensor 102 is configured to include a plurality of rectangular electrodes 110 that are arranged so as to at least partially overlap the display area in a plan view. The plurality of electrodes 110 includes a plurality of first electrodes 111 that extend in a Q direction (first direction) and are spaced apart from each other along a direction perpendicular to the Q direction, and a plurality of second electrodes 112 that extend in a P direction (second direction) that intersects the Q direction and are spaced apart from each other along the direction perpendicular to the Q direction, with at least one of the P direction and the Q direction being inclined with respect to both the X direction and the Y direction.

[0071] In this way, 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, so that a "twist position" relationship can always be maintained between the electrode 110 and the matrix-shaped signal lines, and common mode noise caused by electronic interference with the display panel 130 can be prevented from being mixed into the detection signal of the touch sensor 102.

[0072] In particular, when the display panel 130 displays an image or video for each frame using a "row inversion method" (see FIG. 12A) in which drive voltages are applied alternately and with positive and negative polarities inverted to the gate signal lines 138 extending in the X direction, it is preferable that the P direction and the Q direction are inclined relative to the X direction. By periodically changing the sign of the drive voltage to the gate signal lines 138 spatially and temporally, the generation of common-mode noise is further suppressed.

[0073] Similarly, when the display panel 130 displays an image or video for each frame using a "column line inversion method" (see FIG. 12B) in which drive voltages are applied alternately and with positive and negative polarities inverted to the source signal lines 136 extending in the Y direction, it is preferable that the P direction and the Q direction are each inclined with respect to the Y direction. By periodically changing the sign of the drive voltage to the source signal lines 136 spatially and temporally, the generation of common-mode noise is further suppressed.

[0074] <Second effect> This touch sensor 102 provides another effect in addition to the above-described effect of suppressing common-mode noise. The second effect of the touch sensor 102 will be described below with reference to Fig. 16A and Fig. 16B. Fig. 16A shows a "comparative example" using the touch sensor 14 of the first embodiment, and Fig. 16B shows an "example" using the touch sensor 102 of the second embodiment.

[0075] For example, assume that the aggregation area Aa is located in the lower left corner of the sensor area As, and the wiring layout of the second electrodes 22, 112 closest to the upper long side is designed. For example, in the "Comparative Example" of FIG. 16A, wiring is performed so as to pass through the upper right corner, upper left corner, and lower left corner of the sensor area As, so the wiring length L1 of the specific electrode 20 is relatively long, and the electrical resistance increases accordingly. In contrast, in the "Example" of FIG. 16B, wiring is performed so as to pass through the upper right corner, lower center, and lower left corner of the sensor area As, so the wiring length L2 of the specific electrode 110 is relatively short, and the electrical resistance decreases accordingly.

[0076] In this way, when the touch sensor 102 and the MCU 120 are connected by a plurality of lead wires 156, the electrode 110 spanning two adjacent sides (i.e., the long side and the short side) of the sensor area As may be provided with the lead wire 156 at the end closer to the MCU 120. This makes it easier to shorten the wiring length of a specific electrode 110 compared to when wiring is provided along the periphery of the sensor area As.

[0077] Furthermore, in this touch sensor 102, in addition to the electrodes 110 that bridge two adjacent sides, electrodes 110 that bridge two opposing sides (i.e., both long sides or both short sides) may also be present. This increases the options for which side the lead wire 156 should be provided on. This also has the added effect of increasing the degree of freedom in designing the arrangement of the lead wire 156 compared to the touch sensor 14 of the first embodiment (FIG. 1).

[0078] [Explanation of symbols] 10,100...Electronic device, 12...Electronic pen, 14,102...Touch sensor, 16...Touch IC, 20,110...Electrode, 21,111...First electrode, 22,112...Second electrode, 30...Differential amplifier, 38...MCU (position detection unit), 44,130...Display panel, 56...Heat sink (conductive part), 60...Contour line, 62...End point, 64,66...End electrode, 68...Intersection 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...Metallic thin wire, 156...Lead line, Aa...Aggregation area, Ab...Bezel area, As...Sensor area

Claims

1. A touch sensor used together with a display panel that can display an image or video within a display area by applying a drive voltage to a matrix of signal lines arranged in row and column directions to drive a plurality of pixels, arranged to at least partially overlap the display area in a plan view, The electrode is configured to include a plurality of electrodes arranged in a rectangular shape, The plurality of electrodes are a plurality of first electrodes each having a linear or strip-like outer shape extending in a first direction and arranged at a distance from one another along a direction perpendicular to the first direction; a plurality of second electrodes each having a linear or strip-like outer shape extending in a second direction intersecting the first direction and arranged at a distance from one another along a direction perpendicular to the second direction; Including, the first direction is inclined with respect to both the row direction and the column direction, The touch sensor, wherein the second direction is inclined with respect to both the row direction and the column direction.

2. The touch sensor described in Claim 1, characterized in that the display panel displays an image or video for each frame using a line inversion method in which a driving voltage is applied alternately and with positive and negative inversion to the signal lines extending in the row direction.

3. The touch sensor described in Claim 1, characterized in that the display panel displays an image or video for each frame using a line inversion method in which a driving voltage is applied alternately and with positive and negative inversion to the signal lines extending in the column direction.

4. each of the plurality of first electrodes is made of metal thin wires having a mesh structure in which meshes of the same shape are arranged without gaps in the second direction; Each of the plurality of second electrodes is made of thin metal wires having a mesh structure in which meshes of the same shape are arranged without gaps in the first direction. The touch sensor according to claim 1 .

5. The touch sensor according to any one of claims 1 to 4, a position detection unit that detects a touch position within a sensor area defined by the touch sensor based on a detection signal from the touch sensor; A position detection device comprising:

6. 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 electrode spanning two adjacent sides of the sensor area has the lead wire provided at the end closer to the position detection unit.

6. The position detection device according to claim 5.

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