JP6824827B2 - Touch panel system and electronic devices - Google Patents

Description

The present invention relates to a touch panel system and an electronic device including the touch panel system.

Conventionally, electronic devices such as smartphones and tablets equipped with a touch panel system capable of input operations with a finger or a pen have become widespread. Further, as a touch panel method, a capacitance method that detects a touch by a change in the capacitance on the touch surface is often used.

Such a touch panel system usually has a structure in which a touch panel is laminated on the upper part (front surface) of the display device. Therefore, the sensor provided on the touch panel is susceptible to not only noise such as a clock generated in the display device but also other external noise. Such noise leads to a decrease in the detection sensitivity of the touch operation.

For example, the touch panel system described in Patent Document 1 includes a subtracting unit that calculates a difference between signals of sense lines adjacent to each other, and performs a process of subtracting the noise. Such a noise canceling method is sometimes called a differential reading method.

Further, in recent years, in order to increase the size of the display screen without changing the size of the main body of the electronic device, it has been requested to make the frame area existing around the display screen as small as possible.

Here, in general, a touch sensor in a capacitive touch panel includes a plurality of sense lines and a plurality of drive lines orthogonal to the plurality of sense lines, and wiring is performed from the plurality of sense lines and drive lines. Pulled out. When all the wirings of the plurality of sense lines are pulled out from the same side of the touch sensor, the wiring area of the wirings becomes wide. Therefore, it is difficult to narrow the frame area.

Japanese Unexamined Patent Publication No. 2013-92872 (published on May 16, 2013) Japanese Unexamined Patent Publication No. 2012-185751 (published on September 27, 2012) Japanese Unexamined Patent Publication No. 2015-118537 (published on June 25, 2015) Japanese Unexamined Patent Publication No. 2015-148942 (published on August 20, 2015)

In the touch panel system described in Patent Document 1, how to pull out the wiring is not assumed, and when the wiring is pulled out from a different side of the touch sensor in order to narrow the frame area, the wiring path (the length of the wiring). ) Can be very different. There is a problem that the effect of noise removal can be reduced by the influence of such wiring.

Further, as an example of a touch panel that draws out wiring from different sides of the touch sensor, Patent Document 2 describes that the wiring of a plurality of sense lines in the upper half of the touch sensor is pulled out from one side of the touch sensor and a plurality of wires in the lower half. A touch panel having a structure in which the wiring of the sense line is pulled out from the other side is described. Further, Patent Document 3 and Patent Document 4 describe a touch panel having a structure in which wiring is alternately drawn from the left and right sides of the touch sensor. When the wiring is pulled out in this way, it is easy to narrow the frame area.

However, the touch panels described in Patent Documents 2 to 4 are not assumed to perform noise cancellation by the above-mentioned differential reading method, and even if the noise cancellation is performed, the touch panel system described in Patent Document 1 is the same. Have a problem.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a touch panel system and an electronic device capable of suppressing a decrease in the effect of noise removal when the frame area is narrowed. With the goal.

In order to solve the above problems, the touch panel system according to one aspect of the present invention includes M first sense lines, N second sense lines, and (M and N are plural) L lines arranged on the touch panel. K differential input amplification circuits that amplify the difference in signals from the two-sided wiring sense line (L is an integer of 1 or more) and (K is an integer that satisfies (M + N + L) = (2K + 1)), and the above M lines. M first wiring corresponding to the first sense line, L double-sided wiring corresponding to the L double-sided wiring, and N second wiring corresponding to the N second sense line. A switching circuit having (M + L + N) input terminals to which wirings are connected and (2 × K) output terminals corresponding to the K differential input amplification circuits is provided, and the Mth number is provided. One wiring is connected to the input terminals arranged from the first to the Mth, the both side wirings of the L wires are connected to the input terminals arranged from the (M + 1) th to the (M + L) th, and the second of the N wires is connected. It is characterized in that the wiring is connected to the input terminals arranged from the (M + L + 1) th to the (M + L + N) th.

Further, in order to solve the above-mentioned problems, the electronic device according to one aspect of the present invention is characterized by including the touch panel system described above.

According to one aspect of the present invention, it is possible to provide a touch panel system and an electronic device capable of suppressing a decrease in the effect of noise removal when the frame area is narrowed.

(A) is a schematic diagram showing a basic configuration of a touch panel system according to the first embodiment of the present invention, and (b) is a schematic diagram for explaining a signal flow from the touch panel. (A) is a diagram schematically showing the wiring structure of the touch panel system, and (b) is an enlarged view of a main part in a state where the switch is switched so as to select an input terminal opposite to that of (a). is there. It is a flowchart which shows the noise canceling process which is the basic process of the said touch panel system. It is a top view for demonstrating the reduction of the frame area in the said touch panel system. It is a figure which shows typically the wiring structure of the touch panel system in Embodiment 2 of this invention, (b) is an enlarged view of the main part in the state which a switch is switched to select an input terminal opposite to (a). Is. It is a figure which shows typically the wiring structure of the touch panel system in Embodiment 3 of this invention, (b) is the enlarged view of the main part in the state which a switch is switched to select an input terminal opposite to (a). Is. It is a schematic diagram which shows schematic structure of the touch panel system which has the noise canceling function of the conventional differential reading system. It is a schematic diagram which shows typically an example of the wiring structure of the conventional touch panel system. (A) is a diagram schematically showing a wiring structure when wiring is pulled out from one side of a touch panel in a conventional touch panel system, and (b) is a diagram in which a switch selects a terminal opposite to that of (a). It is an enlarged view of the main part in the state of being switched to. (A) is a diagram schematically showing a wiring structure when wiring is pulled out from both sides of a touch panel in a conventional touch panel system, and (b) is a diagram in which a switch selects a terminal opposite to that of (a). It is an enlarged view of the main part in the state of being switched to. Difference signal This is a difference map of the central part of the touch panel calculated using the processed signal.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, for convenience of explanation, the directions of up, down, left, and right are defined and described as follows. That is, in the in-plane direction on the paper of the drawing, the side on which the drawing number is written is "upper", the opposite side is "lower", the left side when viewing the drawing is "left", and the right side is "right". To do. In addition, the direction of the reader side perpendicular to the paper surface is defined as "front" (or "front side"), and the opposite side is defined as "rear" (or "back side"). That is, for example, the upward direction in the following description is not limited to spatially upward (upper in the vertical direction) unless otherwise specified, and the same applies to other directions.

[Embodiment 1]
In order to facilitate the understanding of the touch panel system according to the embodiment of the present invention, first, the conventional touch panel system and its problems will be described in more detail with reference to FIGS. 7 to 11. The basic configuration, which may be omitted in the description of the touch panel system of the present embodiment to be described later, can be understood by appropriately referring to the description of the conventional touch panel system described below. ..

<Conventional touch panel system>
FIG. 7 is a schematic view schematically showing the structure of the touch panel system 100 having the noise canceling function of the conventional differential reading method. As shown in FIG. 7, the touch panel system 100 includes a display device 110 and a touch panel controller 130, and a plurality of wires drawn from the touch panel 120 included in the display device 110 are connected to the touch panel controller 130.

The touch panel 120 includes a projection type capacitance type sensor unit 121. The sensor unit 121 includes a plurality of sense lines 123 (8 in FIG. 7) and a plurality of drive lines 125 (5 in FIG. 7) orthogonal to the sense line 123. The sense line 123 and the drive line 125 are formed by linear electrodes. The sense line 123 and the drive line 125 are insulated from each other and capacitively coupled. An electric potential is applied to the drive line 125 at regular intervals during the operation of the touch panel system 100.

In the following, a sense sequence consisting of eight sense lines 123 will be described separately as sequences (1) to (8).

The touch panel controller 130 includes a switch 131, a subtraction unit 132, and storage units 133a to 133d in this order from the input side. The switch 131 switches signals input to the subtraction unit 132 from the plurality of sense lines 123. More specifically, the switch 131 has two terminals on the upper and lower sides, and one terminal is selected. FIG. 7 shows a state in which the switch 131 selects the lower terminal.

The subtraction unit 132 performs the difference signal processing of the signals of the sequences (1) to (8) selected by the switch 131. That is, the subtraction unit 132 performs the difference signal processing between the adjacent sense lines 123. For example, as shown in FIG. 7, when the lower terminal is selected by the switch 131, the subtraction unit 132 has an array (8) -array (7), an array (6) -array (5), and an array (4). )-Array (3) and array (2) -array (1) are processed for each difference signal. On the other hand, although not shown, when the upper terminal is selected by the switch 131, the subtraction unit 132 has the array (7) -array (6), the array (5) -array (4), and the array (3)-. Each difference signal processing of the array (2) is performed.

The storage units 133a to 133d store signals (difference processing signals) that have been differentially processed by the subtraction unit 132 when one of the terminals is selected by the switch 131. When the other terminal is selected by the switch 131, the difference processing signal is directly output without passing through the storage units 133a to 133d.

The touch panel system 100 can remove various types of noise by performing such difference signal processing.

Here, as an actual wiring structure of the touch panel system 100, wiring is routed from the touch panel 120 to the touch panel controller 130. Therefore, a problem may occur due to the routing of the wiring. This problem will be described below based on the drawings.

FIG. 8 is a schematic diagram schematically showing an example of the wiring structure of the conventional touch panel system 100. As shown in FIG. 8, the touch panel system 100 has a structure in which the touch panel controller 130 is arranged below the display device 110. Then, all the wiring of the sense line 123 is pulled out from the right side, and the wiring is connected to the touch panel controller 130 by being routed around the frame area A101 between the outer edge of the display device 110 and the touch panel 120. In addition, what will be described below is a wiring routing structure in which the touch panel controller 130 is arranged on the back side of the touch panel 120, and the wiring is curved via a flexible cable or the like and extends from the front side to the back side. But the same is true.

In this case, a large area for wiring the wiring in the frame area A101 is required, and in order to arrange the touch panel 120 in the central portion of the display device 110, it is necessary to provide the frame area A102 in the portion without wiring. Therefore, there is a problem that it is difficult to narrow the frame areas A101 and A102, and it is difficult to further increase the area of the touch panel 120, that is, the display screen area A100.

Therefore, in order to solve this problem, for example, when wiring is pulled out from the two left and right sides of the touch panel 120, areas for routing the wiring can be provided on both sides of the touch panel 120, and the frame areas A101 and A102 are narrowed. can do.

However, the present inventors have found that if the frame regions A101 and A102 are narrowed in this way, a new problem arises in which the effect of noise removal by the difference signal processing may be reduced. This problem will be described with reference to FIGS. 9 and 10.

FIG. 9A is a diagram schematically showing a wiring structure when wiring is pulled out from one side (right side of the figure) of the touch panel 120 in the conventional touch panel system 100, and FIG. 9B is a diagram schematically showing a wiring structure when the switch 131 is (b). It is an enlarged view of the main part in the state which was switched to select the terminal opposite to a). In addition, in order to make it easy to see the wiring routing structure, the switch 131 is shown so as to be located in the lower right direction of the touch panel 120. This also applies to the following description herein.

As shown in FIG. 9A, the touch panel 120 includes 20 sense lines SL0 to SL19 as sense lines 123. The touch panel 120 is connected to the switch 131 by the sense wiring SW0 to SW19 corresponding to each of the sense lines SL0 to SL19. FIG. 9A shows a state in which the switch 131 selects the upper terminal.

The sense wirings SW0 to SW19 are connected to the switch 131 in order from top to bottom, and the subsense wiring SXW is further connected under the sense wiring SW19. The subsense wiring SXW is connected to a subsense line having a reference potential (not shown) for detecting noise.

Further, the subtraction unit 132 includes 10 differential amplifiers 1321 to 1330. The differential amplifier 1321 performs the difference signal processing between the sense line SL0 and the sense line SL1 in the state of FIG. 9A, and in the state of FIG. 9B, the sense line SL1 and the sense line SL2 Performs differential signal processing between and. The differential amplifiers 1322 to 1329 also perform the difference signal processing of the adjacent sense lines in the same manner. The differential amplifier 1330 performs difference signal processing between the sense line SL18 and the sense line SL19 in the state of FIG. 9A, and the sense line SL19 and the subsense line in the state of FIG. 9B. Performs differential signal processing between and.

Various types of noise can be removed by using such a touch panel system 100. On the other hand, in the case of such a wiring structure, the area of the frame area A101 (see FIG. 8) becomes large.

Therefore, it is conceivable to adopt a wiring structure in which wiring is drawn out from the left and right (both sides) of the touch panel 120. FIG. 10A is a diagram schematically showing a wiring structure when wiring is pulled out from both sides of the touch panel 120 in the conventional touch panel system 100, and FIG. 10B is a diagram in which the switch 131 is the reverse of (a). It is an enlarged view of the main part in the state which was switched to select the terminal of.

The sense wirings SW0 to SW9 corresponding to each of the ten sense lines SL0 to SL9 arranged on the upper half of the touch panel 120 are pulled out from the right side of the touch panel 120 and connected to the switch 131. Further, the sense wirings SW10 to SW19 corresponding to each of the ten sense lines SL10 to SL19 arranged in the lower half of the touch panel 120 are pulled out from the left side of the touch panel 120, routed, and connected to the switch 131. ..

By pulling out the wiring in this way, the size of the frame areas A101 and A102 can be halved as compared with the case of FIG.

Here, attention is paid to the sense line SL9 and the sense line SL10 that are adjacent to each other in the central portion of the touch panel 120. The sense wiring SW9 of the sense line SL9 is pulled out to the right side, and the sense wiring SW10 of the sense line SL10 is pulled out to the left side.

In the state of FIG. 10A, the differential amplifier 1325 processes the difference signal between the sense line SL8 and the sense line SL9, and the differential amplifier 1326 performs the difference signal processing between the sense line SL10 and the sense line SL11. Performs differential signal processing. In this case, since the difference in the wiring path between the sense line SL8 and the sense line SL9 and the difference in the wiring path between the sense line SL10 and the sense line SL11 are small, there is no particular problem in removing noise by the difference signal processing.

On the other hand, in the state of FIG. 10B in which the switch 131 selects the lower terminal, the differential amplifier 1325 performs the difference signal processing between the sense line SL9 and the sense line SL10. Here, the difference in the wiring path between the sense line SL9 and the sense line SL10 is large. Therefore, the effect of noise removal by the difference signal processing may be reduced due to such a difference in the wiring path (the influence of the wiring).

FIG. 11 is a difference map (capacity distribution data) of the central portion of the touch panel 120 calculated using the signal for which the difference signal has been processed. As shown in FIG. 11, a noise signal due to a difference in wiring paths is generated in the central portion of the touch panel 120. That is, due to the influence of wiring, the subtraction of the central portion of the touch panel 120 cannot be performed accurately (the effect of noise cancellation becomes small), and noise remains. Therefore, the detection of the touch signal is hindered.

As described above, the conventional touch panel system 100 has a problem that if the frame areas A101 and A102 are narrowed, the effect of noise removal by the difference signal processing may be reduced.

<Touch panel system of this embodiment>
An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

In the present embodiment, a touch panel system including a capacitance type touch panel will be described as an example of the touch panel system of the present invention.

The touch panel system of the present invention is not necessarily limited to this. One aspect of the present invention can be applied to a touch panel system that removes noise by differential signal processing, and the operating principle of the touch panel (sensor operating method) is not particularly limited. For example, it can be applied to a touch panel system including a touch panel having a plurality of touch detection lines, such as a resistive film method, an infrared method, an ultrasonic method, or an electromagnetic induction coupling method. Further, the type of display device is not limited.

The configuration of the touch panel system 1a of the present embodiment will be described with reference to FIG. FIG. 1A is a schematic diagram showing a basic configuration of a touch panel system 1a according to the present embodiment, and FIG. 1B is a schematic diagram for explaining a signal flow from the touch panel 3.

As shown in FIG. 1A, the touch panel system 1a includes a display device 2, a touch panel 3, and a touch panel controller 4, and has a function of removing noise by processing a difference signal. The touch panel controller 4 includes a control unit 30, a drive line drive unit 20, and a detection circuit 10. The detection circuit 10 includes a phase switching unit (switching circuit) 11, a subtraction unit 12, a signal selection unit 13, an A / D conversion unit 14, a decoding processing unit 15, and a touch position detection unit 16. Further, the touch panel system 1a is designed to drive the drive line DrL in parallel. This parallel drive will be described later.

(Display device)
The display device 2 includes a display screen (display unit) (not shown). On the display screen, various icons for operation, character information according to the operation instruction of the user, and the like are displayed. The display device 2 is composed of, for example, a liquid crystal display, a plasma display, an organic EL display, a field emission display (FED), or the like. These displays are often used in everyday electronic devices, and form a highly versatile touch panel system 1a. The display device 2 may have any configuration and is not particularly limited.

(Touch panel)
The touch panel 3 is a projection type capacitance type touch panel in which a user inputs various operation instructions by touching (pressing) the surface of the touch panel 3 with a finger or a pen. The touch panel 3 is laminated on the front surface (upper portion) of the display device 2 so as to cover the display screen.

Here, a specific configuration of the touch panel 3 will be described with reference to FIG. 1 (b). In FIG. 1B, for convenience of explanation, the central portion of the touch panel 3 is enlarged and shown as a part of the touch panel 3. As shown in FIG. 1B, the touch panel 3 includes a sensor unit 3a and detects a touch operation by the user. This touch operation includes a double-click operation, a slide operation, a single-click operation, a drag operation, and the like.

The sensor unit 3a includes a plurality of sense lines SL and a plurality of drive lines DrL intersecting each sense line SL. In this embodiment, the sense line SL is 20 lines and the drive line DrL is 28 lines. The sense line SL and the drive line DrL are each insulated from each other and capacitively coupled. A plurality of sense lines SL (20 lines in this embodiment) are provided in parallel with each other and at equal intervals. A plurality of drive lines (28 in this embodiment) are also provided in parallel with each other and at equal intervals.

Here, the plurality of sense lines SL (10 in the present embodiment) on the upper side of the drawing in the sensor unit 3a of the present embodiment are collectively referred to as the first sense line group SLG1, and the plurality of sense lines SL on the lower side (10 in the present embodiment). In this embodiment, 10 lines) are collectively referred to as a second sense line group SLG2. The sensor unit 3a further provides one bilateral wiring sense line provided in parallel with the sense line SL (extending in the same direction) between the first sense line group SLG1 and the second sense line group SLG2. I have. As will be described in detail later, the two-sided wiring sense line is connected to the wiring at both ends in the longitudinal direction, and can be more specifically referred to as a double routing Sense line. .. For the sake of brevity, the bilateral wiring sense lines will be referred to as bilateral sense lines DRSL in the description and drawings herein.

A plurality of double-sided sense lines DRSL may be provided.

In other words, the touch panel 3 includes 10 first sense line SLFs constituting the first sense line group SLG1, at least one bilateral sense line DRSL, and 10 lines constituting the second sense line group SLG2. The second sense line SLS and is arranged. In the touch panel 3, the sense line SL and the sense lines on both sides DRSL provided in the horizontal direction and the drive line DrL provided in the vertical direction are arranged in a two-dimensional matrix.

Both side sense lines DRSL are provided on the same plane as the above 20 sense lines SL. The two-sided sense line DRSL may use, for example, one of the plurality of sense lines SL included in the sensor unit 3a as the two-sided sense line DRSL, and has the same function as the sense line SL. The double-sided sense lines DRSL may be provided on substantially the same plane as the above 20 sense lines SL. The two-sided sense line DRSL may be arranged so that the noise generated by the two-sided sense line DRSL and the noise generated by the sense line SL adjacent to the both-side sense line DRSL have the same noise.

The sense line SL, the bilateral sense line DRSL, and the drive line DrL each consist of linear electrodes. The sense line SL, the double-sided sense line DRSL, and the drive line DrL may be composed of electrodes arranged in a straight line, and the electrode shape may be a known shape. That is, the electrode shape is not particularly limited.

One end of each sense line SL and the phase switching unit 11 of the touch panel controller 4 are connected to each other by wiring. This wiring will be referred to as a sense wiring SW below. A bundle of sense wiring SWs connected to a plurality of first sense line SLFs constituting the first sense line group SLG1 is referred to as a first sense wiring group SLG1. Further, a bundle of sense wiring SWs connected to a plurality of second sense lines SLS constituting the second sense line group SLG2 is referred to as a second sense wiring group SWG2.

In the present embodiment, the first sense wiring group SWG1 and the second sense wiring group SWG2 each include 10 wirings. That is, the first sense wiring group SWG1 is composed of 10 first sense wiring (first wiring) SWFs corresponding to 10 first sense line SLFs, and the second sense wiring group SWG2 has 10 lines. It is composed of 10 second sense wiring (second wiring) SWS corresponding to each of the second sense line SLS.

The first sense wiring group SWG1 is pulled out from the right side of the sensor unit 3a as the first direction and is connected to the phase switching unit 11. The second sense wiring group SWG2 is pulled out from the left side of the sensor unit 3a as the second direction opposite to the first direction, is routed, and is connected to the phase switching unit 11. In other words, the first sense line SLF is pulled out from the touch panel 3 along the first direction and connected to the first sense wiring SWF, and the second sense line SLF is opposite to the first direction. It is pulled out from the touch panel 3 along the second direction and connected to the second sense wiring SWS.

Further, the wiring is pulled out from both sides of the sense line DRSL on both sides, and the two wirings merge and are connected to the phase switching unit 11 of the touch panel controller 4. The wiring of the two-sided sense line DRSL (both-sided wiring DRW) will be described in detail later.

It should be noted that various sense lines SL, both-sided sense lines DRSL, and each wiring may be connected so as to be energized, and the specific mode of connection such as the position of the connection portion is not particularly limited. ..

The signal detected by the sensor unit 3a is output to the phase switching unit 11 via each sense wiring SW and both-side wiring DRW. That is, the signal corresponding to the touch operation detected by the sensor unit 3a is output to the phase switching unit 11.

The sense line SL, drive line DrL, and bilateral sense line DRSL can all be formed from a transparent wiring material such as ITO (Indium Thin Oxide). It can be said that the sense line SL, the drive line DrL, and the double-sided sense line DRSL are sensor electrodes in the touch panel 3.

The drive line DrL is provided on a transparent substrate or a transparent film (not shown). Further, the driveline DrL is covered with an insulating layer (not shown). A sense line SL and a sense line DRSL on both sides are provided on this insulating layer. In this way, the sense line SL or the sense line DRSL on both sides and the drive line DrL are insulated from each other via an insulating layer and are capacitively coupled. The sense line SL and the bilateral sense line DRSL are covered with a protective layer (not shown). That is, in the touch panel 3, the protective layer is arranged on the frontmost side (user side).

The number, length, width, spacing, etc. of the sense line SL, the sense lines DRSL on both sides, and the drive line DrL can be arbitrarily set depending on the application of the touch panel system 1a, the size of the touch panel 3, and the like.

(Touch panel controller)
The touch panel controller 4 controls the drive line drive unit 20 that drives the drive line DrL, the detection circuit 10 that reads the signal (data) input from the sensor unit 3a to detect the touch position, and controls each unit in an integrated manner. It is provided with a unit 30.

Since the touch panel system 1a includes a capacitance type sensor, the touch panel controller 4 detects the capacitance generated by the touch panel 3. Specifically, the touch panel controller 4 detects a change in capacitance between the sense line SL and the drive line DrL, and a change in capacitance between the sense line DRSL and the drive line DrL on both sides.

(Drive line drive unit)
The drive line drive unit 20 drives the drive line DrL in parallel based on the signal from the control unit 30. Since the specific configuration of the parallel drive and the processing of the detected capacitance signal are known methods, detailed description thereof will be omitted for convenience of explanation, but the decoding processing unit 15 will be generally described. It will be described later together with.

(Detection circuit)
The detection circuit 10 includes a phase switching unit 11, a subtraction unit 12, a signal selection unit 13, an A / D conversion unit 14, a decoding processing unit 15, and a touch position detection unit 16 in this order from the input side.

{Phase switching part}
As shown in FIG. 1B, the phase switching unit (switching circuit) 11 includes an input terminal group 11a, a switch 11b, and an output terminal group 11c in this order from the input side. The input terminal group 11a and the output terminal group 11c each have a plurality of terminals corresponding to individual signal flows. The input terminal group 11a has at least the same number of input terminals Imp as the total of the sense line SL and the sense lines DRSL on both sides of the touch panel 3. The output terminal group 11c has at least a number of output terminals Out corresponding to a plurality of differential amplifiers 12a described later.

The switch 11b switches the signal input to the subtraction unit 12 from the sense line SL and the double-sided sense line DRSL. More specifically, the switch 11b has one of two adjacent input terminals Imp (arranged at the top and bottom of the figure) having one end connected to one output terminal Out and the other end corresponding to the output terminal Out. It is designed to be selected and connected.

Assuming that the state in which the switch 11b selects the upper input terminal Imp is the first phase and the state in which the lower input terminal Imp is selected is the second phase, the phase switching unit 11 performs the first phase and the first phase. It is possible to switch between two phases. The signal switching by the switch 11b will be described in detail later together with the description of the noise processing of the touch panel system 1a.

The first sense wiring group SWG1, the second sense wiring group SWG2, and the bilateral wiring DRW (two-path wiring) are connected to the input terminal group 11a of the phase switching unit 11, respectively. Here, the first sense wiring group SWG1 is pulled out from the right side of the touch panel 3 and is collectively connected to the input terminal group 11a so that the first sense wiring SWFs are adjacent to each other. Further, the second sense wiring group SWG2 is pulled out from the left side of the touch panel 3, is routed around the touch panel 3, and is connected to the input terminal group 11a together so that the second sense wiring SWSs are adjacent to each other. There is.

Then, the wiring DRWs on both sides are connected to the input terminal group 11a between the first sense wiring group SWG1 and the second sense wiring group SWG2. Here, the double-sided wiring DRW is pulled out from both ends of the double-sided sense line DRSL, and the two wirings merge and are connected to the input terminal group 11a. Specifically, the bilateral wiring DRW is (i) drawn from the right side of the bilateral sense line DRSL (pulled out from the touch panel 3 along the first direction), and extends along the first sense wiring SWF. It is pulled out from the left side of the double-sided wiring (first route wiring) DRW1 and (ii) both-sided sense line DRSL (pulled out from the touch panel 3 along the second direction), and is drawn around the touch panel 3. 2 Sense wiring Includes a second side wiring (second path wiring) DRW2 extending along the SWS.

The double-sided wiring DRW includes a wiring merging portion 40 in which the first double-sided wiring DRW1 and the second double-sided wiring DRW2 merge in the middle. One double-sided wiring DRW (third double-sided wiring DRW3 (see FIG. 2)) formed by the wiring merging portion 40 is connected to the input terminal group 11a of the phase switching portion 11. The specific configuration of the wiring confluence 40 is not particularly limited.

The subtraction unit 12, the signal selection unit 13, the A / D conversion unit 14, the decoding processing unit 15, and the touch position detection unit 16 will be described below, but known techniques are applied to the arithmetic processing performed by each of these units. Therefore, detailed description will be omitted for convenience of description.

{Subtraction part}
As shown in FIG. 1B, the subtraction unit 12 includes a plurality of (10 in this embodiment) differential amplifiers (differential input amplifier circuits) 12a. Here, the output signals from the sense line SL and the sense lines DRSL on both sides of the touch panel 3 are analog signals and linear sum signals obtained by driving the drive lines DrL in parallel.

The differential amplifier 12a is an analog linear sum signal selected by the switch 11b of the phase switching unit 11 and output from the adjacent sense line SL or output from the adjacent sense line SL and both side sense line DRSL. It is an operational amplifier that amplifies the difference between.

That is, the subtraction unit 12 receives the signal from the sensor unit 3a and calculates the difference signal value between the lines adjacent to each other, which have a higher noise correlation. The signal subtracted by the subtraction unit 12 is output to the signal selection unit 13.

The differential amplifier 12a may be a fully differential amplifier capable of rail-to-rail operation. In this case, the fully differential amplifier can operate in the voltage range from the power supply voltage (Vdd) to GND, and the output signal from the subtraction unit 12 does not have the problem of output saturation.

{Signal selection unit}
As shown in FIG. 1B, the signal selection unit 13 includes a plurality of storage units 13a. The storage unit 13a stores a signal (difference processing signal) that has been differentially processed by the subtraction unit 12 when one of the terminals is selected by the switch 11b. The difference processing signal stored in the storage unit 13a is output to the A / D conversion unit 14. When the other terminal is selected by the switch 11b, the difference processing signal does not pass through the storage unit 13a.

The signal selection unit 13 has a function as a so-called sample hold circuit and a function as a multiplexer, and each signal received from the subtraction unit 12 is transmitted to the A / D conversion unit 14 at an appropriate timing. ing.

{A / D converter}
The A / D conversion unit 14 performs subtraction processing by the subtraction unit 12, and converts the analog signal received via the signal selection unit 13 into a digital signal.

{Decoding processing unit}
The decoding processing unit 15 decodes the digital signal obtained by converting the difference value of the capacitance calculated by the subtraction unit 12 by the A / D conversion unit 14. A known configuration can be applied to the parallel drive of the drive line DrL in the touch panel system 1a and the decoding in the decoding processing unit 15. The outline is as follows. In the following, for convenience of explanation, the sense line SL and the double-sided sense line DRSL will be described without distinction.

The decoding processing unit 15 calculates the inner product of the code sequence that drives the drive line DL in parallel and the difference distribution of the capacitance values in the sense line SL direction. In the decoding processing unit 15, the difference distribution of the capacitance value in the sense line SL direction is multiplied by N and calculated as the main component of the inner product value after decoding. N is the code length of the code sequence.

Therefore, the dot product value Is an estimated value of the difference distribution of the capacitance values in the sense line SL direction, so that the signal strength of the capacitance values can be read out by N times (code length multiple). As a result, the drive time of the drive line DrL is shortened to 1 / N in the case of the drive system in which the drive line DrL is sequentially driven. That is, the number of times the drive line DrL is driven can be reduced. Therefore, the power saving of the touch panel system 1a becomes possible.

{Touch position detector}
The process executed by the touch position detection unit 16 may be the same as the process performed by a known touch panel controller. The touch position detection unit 16 creates a difference map showing the difference distribution of the signals of each sense line SL based on the difference of the signals of the sense lines SL adjacent to each other from which the noise signal is removed. By recognizing touch information (touch size, position, etc.) based on this difference map, it is possible to recognize touch information in addition to the presence or absence of touch operation.

(Control unit)
The control unit 30 includes an arithmetic processing unit such as a CPU (Central Processing Unit) or a dedicated processor, and memory components such as a RAM (Random Access Memory), a ROM (Read Only Memory), and an HDD (Hard Disc Drive). It is composed of (not shown) and the like, and reads and executes various information stored in the memory component and a program for executing various controls. The control unit 30 comprehensively controls each unit of the drive line drive unit 20 and the detection circuit 10.

(Wiring structure of the touch panel system of this embodiment)
Here, the wiring structure of the touch panel system 1a will be described in more detail with reference to FIGS. 2A and 2B. FIG. 2A is a diagram schematically showing a wiring structure of the touch panel system 1a, and FIG. 2B is a main part in a state where the switch 11b is switched so as to select a terminal opposite to that of FIG. 2A. It is an enlarged view.

As shown in FIG. 2A, the touch panel 3 is a first sense line group consisting of 10 first sense line SLFs, 10 second sense line SLSs, and 10 first sense line SLFs. It has one bilateral sense line DRSL arranged between the SLG1 and the second sense line group SLG2 composed of 10 second sense lines SLS.

The 10 first sense lines SLF are designated as sense lines SL0 to sense line SL9 in order from the top of the touch panel 3, and the 10 second sense line SLSs are designated as sense lines SL10 to sense line SL19 in order from the top of the touch panel 3. And. Both side sense lines DRSL are arranged between the sense line SL9 and the sense line SL10.

Sense lines SL0 to Senselines SL9 are each drawn out from the right side of the touch panel 3 (along the first direction) and connected to 10 first sense wiring SWFs. The ten first sense wiring SWFs corresponding to each of the sense lines SL0 to SL9 are designated as sense wiring SW0 to SW9, respectively.

Further, each of the sense lines SL10 to SL19 is pulled out from the left side of the touch panel 3 (along the second direction opposite to the first direction) and connected to the ten second sense wiring SWSs. The ten second sense wiring SWS corresponding to each of the sense lines SL10 to SL19 are referred to as sense wiring SW10 to SW19, respectively.

The sense wirings SW0 to SW9 are connected to the input terminal group 11a through the path on the right side of the touch panel 3. The sense wirings SW10 to SW19 are drawn out from the left side of the touch panel 3 and are connected to the input terminal group 11a through a path longer than the sense wirings SW0 to SW9. That is, the touch panel system 1a has a configuration in which the sense wirings SW0 to SW9 and the sense wirings SW10 to SW19 have different wiring paths (wiring lengths) from the touch panel 3 to the touch panel controller 4.

The double-sided sense line DRSL is drawn out from the right side of the touch panel 3 and connected to the first double-sided wiring DRW1, and is drawn out from the left side of the touch panel 3 and connected to the second double-sided wiring DRW2. The first double-sided wiring DRW1 extends along a path along the sense wirings SW0 to SW9, and the second double-sided wiring DRW2 extends along a path along the sense wirings SW10 to SW19.

Then, the first-sided wiring DRW1 and the second-sided wiring DRW2 are merged at the wiring merging portion 40, and one third-sided wiring DRW3 after merging is connected to the input terminal Imp. That is, the double-sided wiring DRW includes a first double-sided wiring DRW1, a second double-sided wiring DRW2, and a third double-sided wiring DRW3.

The input terminals Imp to which the sense wirings SW0 to SW9, the third side wiring DRW3, and the sense wirings SW10 to SW19 are connected are designated as input terminals Imp1, Imp2, ..., Imp21, respectively, from the top of the figure. The sense wirings SW0 to SW9 are connected to the input terminals Imp1 to Imp10, the third side wiring DRW3 is connected to the input terminals Imp11, and the sense wirings SW10 to SW19 are connected to the input terminals Imp12 to Imp21, respectively.

Further, the plurality of output terminals Out connected to the input terminal Imp via the switch 11b are designated as output terminals Out1, Out2, ..., Out20 in order from the top of the figure. Then, the differential amplifier 12a that receives the signal from each output terminal Out is referred to as a differential amplifier 12a1, a differential amplifier 12a2, ..., And a differential amplifier 12a10 in order from the top of the figure.

The state of FIG. 2A in which the switch 11b selects the upper input terminal is referred to as the first phase, and the state of FIG. 2B in which the switch 11b selects the lower input terminal is the first phase. It will be referred to as two phases.

In the first phase shown in FIG. 2A, the combinations of signals input to the differential amplifiers 12a1 to 12a5 via the input terminal group 11a, the switch 11b, and the output terminal group 11c are (SL0, SL1), respectively. , (SL2, SL3), (SL4, SL5), (SL6, SL7), (SL8, SL9), and the combinations of signals input to the differential amplifiers 12a6 to 12a10 are (DRSL, SL10), (DRSL, SL10), respectively. SL11, SL12), (SL13, SL14), (SL15, SL16), (SL17, SL18).

On the other hand, in the second phase shown in FIG. 2B, the combinations of signals input to the differential amplifiers 12a1 to 12a5 via the input terminal group 11a, the switch 11b, and the output terminal group 11c are each (SL1, SL2), (SL3, SL4), (SL5, SL6), (SL7, SL8), (SL9, DRSL), and the combinations of signals input to the differential amplifiers 12a6 to 12a10 are (SL10, SL11), respectively. , (SL12, SL13), (SL14, SL15), (SL16, SL17), (SL18, SL19).

As described above, in the touch panel system 1a of the present embodiment, in both the first phase and the second phase, the first sense line SLF of the first sense line group SLG1 and the second sense line SLS of the second sense line group SLG2 Is never input to the same differential amplifier 12a.

Here, the double-sided sense line DRSL has the same configuration as the sense line SL on the touch panel 3, and the double-sided wiring DRW provides the wiring path components of both the first sense wiring group SWG1 and the second sense wiring group SWG2. Since it is configured to include, the following can be said when the sense line SL is affected by external noise. That is, the signal input to the input terminal Imp11 to which the double-sided wiring DRW is connected is input to the signal input to the adjacent input terminal Imp10 (the signal from the sense line SL9 input through the sense wiring SW9) and the input terminal Imp12. It contains the same noise component as the signal (signal from the sense line SL10 input through the sense wiring SW10).

Therefore, external noise can be removed by taking a differential between the sense line DRSL on both sides and the sense line SL9 or the sense line SL10.

From the above points, the double-sided sense line DRSL can also be referred to as a shared sense line (share sense line) shared by the first sense line SLF and the second sense line SLS in the calculation of the difference signal.

<Noise processing of the touch panel system of this embodiment>
The noise canceling process of the touch panel system 1a will be described with reference to FIG. FIG. 3 is a flowchart showing a noise canceling process which is a basic process of the touch panel system 1a of the present embodiment.

When the touch panel system 1a is activated, the drive line drive unit 20 drives the drive line DrL in parallel. When the user touches the touch panel 3, the capacity of the specific sense line SL corresponding to the touch position increases. That is, the output signal value from the sense line SL increases.

The touch panel system 1a outputs the output signals from the sense line SL and the sense line DRSL on both sides to the touch panel controller 4 while driving each drive line DrL (step 1: hereinafter abbreviated as S1). In this way, the touch panel system 1a detects the capacitance change of the sense line SL and the sense line DRSL on both sides while driving the drive line DrL, and detects the presence / absence of the touch operation and the touch position.

More specifically, noise such as a clock generated by the display device 2 and noise from other external sources are reflected on the touch panel 3. Therefore, a noise signal (noise component) is added to the original signal of the touch operation in the output signals from the sense line SL and the double-sided sense line DRSL.

Next, in the switch 11b of the phase switching unit 11, the upper input terminal Imp is selected (S2).

Then, the subtraction unit 12 calculates the following (i) to (iii) (S3).

(I) The difference between the adjacent sense lines SL of the first sense line group SLG1 is calculated. Specifically, each difference signal processing of the sense line SL0-sense line SL1, the sense line SL2-sense line SL3, the sense line SL4-sense line SL5, the sense line SL6-sense line SL7, and the sense line SL8-sense line SL9. The differential amplifiers 12a1 to 12a5 perform the above, respectively.

(Ii) The difference between the bilateral sense line DRSL and the bilateral sense line DRSL of the second sense line group SLG2 and the adjacent sense line SL10 is calculated. Specifically, the differential amplifier 12a6 processes the difference signal of the two-sided sense line DRSL-sense line SL10.

(Iii) The difference between the remaining sense lines SL11 to the sense lines SL19 of the second sense line group SLG2 and the adjacent sense lines SL is calculated. Specifically, the differential amplifiers 12a7 to perform the difference signal processing of the sense line SL11-sense line SL12, the sense line SL13-sense line SL14, the sense line SL15-sense line SL16, and the sense line SL17-sense line SL18, respectively. The differential amplifier 12a10 performs this.

The difference signal calculated by the subtraction unit 12 in S3 is stored in the storage unit 13a (S4).

Next, the switch 11b in which the upper input terminal Imp is selected is switched so as to select the lower terminal (S5). Then, the subtraction unit 12 processes in the same manner as in S3. That is, the subtraction unit 12 calculates the following (i) to (iii) (S6).

(I) In the first sense line group SLG1, the difference between the sense lines SL1 to the sense lines SL8 other than the sense lines SL9 adjacent to the sense lines DRSL on both sides is calculated. Specifically, the differential amplifiers 12a1 to perform the difference signal processing of the sense line SL1-sense line SL2, the sense line SL3-sense line SL4, the sense line SL5-sense line SL6, and the sense line SL7-sense line SL8, respectively. The differential amplifier 12a4 performs this.

(Ii) The difference between the two-sided sense line DRSL and the adjacent sense line SL9 in the first sense line group SLG1 and the two-sided sense line DRSL is calculated. Specifically, the differential amplifier 12a5 processes the difference signal between the sense line SL9 and the double-sided sense line DRSL.

(Iii) The difference between the adjacent sense lines SL of the second sense line group SLG2 is calculated. Specifically, each difference signal processing of the sense line SL10-sense line SL11, the sense line SL12-sense line SL13, the sense line SL14-sense line SL15, the sense line SL16-sense line SL17, and the sense line SL18-sense line SL19. The differential amplifier 12a6 to the differential amplifier 12a10 perform the above, respectively.

Next, the signal selection unit 13 transmits the difference signal calculated by the subtraction unit 12 in S6 and the difference signal calculated by the subtraction unit 12 in S3 and stored in the storage unit 13a to the A / D conversion unit 14. Transmit to convert each signal into a digital signal. Then, the decoding processing unit 15 decodes the A / D-converted signal to obtain an estimated value of the difference distribution of the capacitance values in the sense line SL direction (S7).

The decoding processing unit 15 transmits the processed data to the touch position detection unit 16 (S8). The touch position detection unit 16 creates a difference map showing the difference distribution of the signals of each sense line SL based on the received data. Touch information (touch size, position, etc.) can be recognized based on this difference map.

<Advantages of the touch panel system of this embodiment>
The advantages of the touch panel system 1a of the present embodiment will be described below with reference to FIG. FIG. 4 is a plan view for explaining the reduction of the frame area in the touch panel system 1a.

As shown in FIG. 4, the touch panel 3 is laminated on the front surface of the display device 2 and arranged so that the left and right frame areas A2 of the touch panel 3 are evenly arranged. From the right side of the touch panel 3, the first sense wiring group SWG1 connected to the first sense line group SLG1 is pulled out, and the first double-sided wiring DRW1 connected to both side sense lines DRSL is pulled out. Further, from the left side of the touch panel 3, the second sense wiring group SWG2 connected to the second sense line group SLG2 is pulled out, and the second side wiring DRW2 connected to the both side sense line DRSL is pulled out.

As described above, in the touch panel system 1a, since the wiring is pulled out from the left and right sides of the touch panel 3, the area required for routing the wiring can be narrowed. Therefore, the left and right frame areas A2 of the touch panel 3 can be narrowed to increase the display screen area A1 of the touch panel 3.

Further, in the touch panel system 1a, in the wiring path in the frame area A2, the first double-sided wiring DRW1 passes through the side closer to the touch panel 3 than the first sense wiring group SWG1, and the second double-sided wiring DRW2 is the second sense wiring. It passes through the side farther from the touch panel 3 than the group SWG2. As a result, the plurality of wires drawn from the touch panel 3 can be aligned and passed through the frame area A2 without intersecting each other.

Here, by calculating the difference between the signals from the adjacent sense lines SL, it is possible to remove (cancel) various types of noise reflected on the touch panel 3. However, when the wiring paths are significantly different, the effect of noise removal can be reduced due to the influence of the wiring.

Therefore, in the touch panel system 1a, the wiring from the sense lines DRSL on both sides is connected to the input terminal group 11a by merging the first side wiring DRW1 and the second side wiring DRW2 at the wiring merging portion 40 in the middle of the wiring. (See (a) in FIG. 2). Therefore, the bilateral wiring DRW is configured to include the wiring path components of both the first sense wiring group SWG1 and the second sense wiring group SWG2.

Therefore, when the difference between the signal from the sense line DRSL on both sides and the signal from the first sense line SLF and the second sense line SLS adjacent to the sense line DRSL on both sides is calculated, the touch panel 3 is determined by the difference in the wiring path. It is possible to suppress the phenomenon that the effect of noise removal in the central portion of the above is reduced.

Therefore, the touch panel system 1a can suppress the reduction of the effect of noise removal while narrowing the frame area A2 (frame area).

The touch panel system 1a of the present embodiment can be applied to various touch panel type electronic devices. Examples of electronic devices include televisions, personal computers, mobile phones, digital cameras, portable game machines, electronic photo frames, personal digital assistants (PDAs), electronic books, home appliances (microscopes, washing machines, etc.), Ticket vending machines, ATMs (Automated Teller Machines), car navigation systems, etc. can be mentioned. As a result, it is possible to provide an electronic device capable of suppressing a decrease in the effect of noise removal when the frame area is narrowed.

<Other configurations>
The configuration described above can be expressed in a more generalized manner as follows.

The touch panel 3 has M first sense lines SLF, N second sense lines SLS (plural M and N), and L both side sense lines DRSL (L is an integer of 1 or more). ing. Let K be the number of differential amplifiers 12a included in the subtraction unit 12. Here, K is an integer that satisfies (M + N + L) = (2K + 1).

The M first sense wiring SWFs corresponding to each of the M first sense lines SLF are connected to the first to Mth input terminals Imp (input terminals Imp1 to ImpM) arranged in the phase switching unit 11. To. The L double-sided wiring DRWs corresponding to each of the L double-sided sense lines DRSL are the M + 1st to M + Lth input terminals Imp (input terminals Imp (M + 1) to Imp (M + L)) arranged in the phase switching unit 11. Connected to. Then, the N second sense wiring SWSs corresponding to each of the N second sense lines SLS are arranged in the phase switching unit 11 from the M + L + 1st to the M + L + Nth input terminals Imp (input terminals Imp (M + L + 1) to It is connected to Imp (M + L + N)).

The phase switching unit 11 includes (2 × K) output terminals Out corresponding to the K differential amplifiers 12a. The input terminal Imp connected to the output terminal Out is switched by the switch 11b of the phase switching unit 11. As a result, the subtraction unit 12 calculates the difference between the signals of the adjacent sense line SL and the bilateral sense line DRSL of the touch panel 3.

From the L double-sided sense lines DRSL, a first double-sided wiring DRW1 extending along the path of the first sense wiring SWF and a second double-sided wiring DRW2 extending along the path of the second sense wiring SWS are drawn out, respectively. ing. The first-sided wiring DRW1 and the second-sided wiring DRW2 of the respective two-sided sense lines DRSL are merged at the wiring merging portion 40 in the middle of the wiring path, and then input terminals Imp (input terminals Imp (M + 1) to Imp (M + L). )) Is connected.

(Modification example)
(A) The first-sided wiring DRW1 and the second-sided wiring DRW2 may be directly connected to the input terminal group 11a as separate wirings without merging. In this case, for example, the input terminal Imp11 in FIG. 2A has a first input terminal corresponding to the first double-sided wiring DRW1 and a second input terminal corresponding to the second double-sided wiring DRW2. It is sufficient that the second input terminal and the differential amplifier 12a6 are connected in the first phase, and the first input terminal and the differential amplifier 12a5 are connected in the second phase. It is clear that such a configuration also falls within the scope of the present invention.

(B) The wiring structure shown in FIG. 2A is an example. For example, the sense lines SL10 to Senseline SL19 as the second senseline group SLG2 in the touch panel 3 are opposite to the input terminal group 11a, respectively. They may be connected in order. Specifically, the wiring may be routed so that the sense line SL19 to the sense line SL10 are connected to the input terminal Imp12 to the input terminal Imp21 in this order.

(C) The drive line drive unit 20 may drive a plurality of drive lines DrL in sequence instead of driving them in parallel. In this case, the detection circuit 10 does not have to include the decoding processing unit 15.

[Embodiment 2]
Other embodiments of the present invention will be described below with reference to FIG. The configuration other than that described in the present embodiment is the same as that in the first embodiment. Further, for convenience of explanation, the members having the same functions as the members shown in the drawings of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the touch panel system 1a of the first embodiment, both side sense lines DRSL are arranged between the first sense line group SLG1 and the second sense line group SLG2 in the touch panel 3. On the other hand, the touch panel system 1b of the present embodiment is different in that both side sense lines DRSL are arranged below the second sense line group SLG2, that is, at a position adjacent to the sense line SL19.

The wiring structure of the touch panel system 1b of the present embodiment will be described with reference to FIGS. 5A and 5B. FIG. 5A is a diagram schematically showing a wiring structure of the touch panel system 1b, and FIG. 5B is a main part in a state where the switch 11b is switched so as to select a terminal opposite to that of FIG. 5A. It is an enlarged view.

The touch panel 3 of the touch panel system 1b is arranged adjacent to the second sense line group SLG2 consisting of 10 first sense line SLF, 10 second sense line SLS, and 10 second sense line SLS. It has only one double-sided sense line DRSL.

That is, on the touch panel 3, in order from the top in the drawing, the sense line SL0 to the sense line SL9 (first sense line group SLG1), the sense line SL10 to the sense line SL19 (second sense line group SLG2), and both side sense lines DRSL. Is placed.

Also in this case, the double-sided sense line DRSL is drawn out from the right side of the touch panel 3 and connected to the first double-sided wiring DRW1, and is also drawn out from the left side of the touch panel 3 and connected to the second double-sided wiring DRW2. The first double-sided wiring DRW1 extends along a path along the sense wirings SW0 to SW9, and the second double-sided wiring DRW2 extends along a path along the sense wirings SW10 to SW19.

Then, the first-sided wiring DRW1 and the second-sided wiring DRW2 are merged at the wiring merging portion 40, and one third-sided wiring DRW3 after merging is connected to the input terminal group 11a.

The plurality of input terminals Imp are designated as input terminals Imp1, Imp2, ..., Imp21 in order from the top of the figure. The sense wirings SW0 to SW9 are connected to the input terminals Imp1 to Imp10, the third side wiring DRW3 is connected to the input terminals Imp11, and the sense wirings SW10 to SW19 are connected to the input terminals Imp12 to Imp21, respectively.

The double-sided wiring DRW is configured to include both wiring path components of the first sense wiring group SWG1 (sense wiring SW0 to SW9) and the second sense wiring group SWG2 (sense wiring SW10 to SW19).

Therefore, when the subtraction unit 12 executes the difference signal processing, the difference between the signal from the double-sided sense line DRSL and the signal from the second sense line SLS (sense line SL19) adjacent to the double-sided sense line DRSL, and the double-sided sense. When the difference between the signal from the line DRSL and the signal from the first sense line SLS (sense line SL9) is calculated, it is possible to suppress the phenomenon that the noise removal effect is reduced due to the difference in the wiring path. be able to.

Therefore, it is possible to suppress the reduction of the noise removal effect while narrowing the frame area.

Further, since the sense lines DRSL on both sides are provided at the end of the touch panel 3, the effective touch area can be further expanded.

[Embodiment 3]
Another embodiment of the present invention will be described below with reference to FIG. The configurations other than those described in the present embodiment are the same as those in the first and second embodiments. Further, for convenience of explanation, members having the same functions as the members shown in the drawings of the first and second embodiments are designated by the same reference numerals, and the description thereof will be omitted.

In the touch panel system 1b of the second embodiment, of the plurality of sense lines SL arranged on the touch panel 3, the upper half is the first sense line group SLG1 and the lower half is the second sense line group SLG2. On the other hand, in the touch panel system 1c of the present embodiment, among the plurality of sense lines SL arranged on the touch panel 3, a set of even-numbered sense line SLs counted from the top is designated as the first sense line group SLG1. The difference is that the set of odd-numbered sense lines SL is the second sense line group SLG2.

The wiring structure of the touch panel system 1c of the present embodiment will be described with reference to FIGS. 6A and 6B. FIG. 6A is a diagram schematically showing a wiring structure of the touch panel system 1c, and FIG. 6B is a main part in a state where the switch 11b is switched so as to select a terminal opposite to that of FIG. 6A. It is an enlarged view.

The touch panel 3 of the touch panel system 1c has ten first sense lines SLF, ten second sense lines SLS, and one double-sided sense line DRSL. The first sense line group SLG1 composed of the ten first sense lines SLF is a set of even numbered sense lines SL from the top of the touch panel 3, specifically, sense lines SL0, sense lines SL2, ... , Includes Senseline SL18. The second sense line group SLG2 composed of 10 second sense lines SLS is a set of odd-numbered sense lines SL from the top of the touch panel 3, specifically, sense lines SL1, sense lines SL3, and so on. -Includes the sense line SL19. Both side sense lines DRSL are arranged adjacent to the sense line SL19.

The first sense wiring group SWG1 composed of ten first sense wiring SWFs corresponding to the first sense line group SLG1 is pulled out from the right side of the touch panel 3. Specifically, the ten first sense wiring SWFs are the sense wiring SW0, the sense wiring SW2, ..., And the sense wiring SW18, respectively. Further, the second sense wiring group SWG2 composed of ten second sense wiring SWS corresponding to the second sense line group SLG2 is pulled out from the left side of the touch panel 3. Specifically, the ten second sense wiring SWSs are the sense wiring SW1, the sense wiring SW3, ..., And the sense wiring SW19, respectively.

The double-sided sense line DRSL is drawn out from the right side of the touch panel 3 and connected to the first double-sided wiring DRW1, and is drawn out from the left side of the touch panel 3 and connected to the second double-sided wiring DRW2. The first double-sided wiring DRW1 extends along a path along the first sense wiring group SWG1, and the second double-sided wiring DRW2 extends along a path along the second sense wiring group SWG2. Then, the first-sided wiring DRW1 and the second-sided wiring DRW2 are merged at the wiring merging portion 40, and one third-sided wiring DRW3 after merging is connected to the input terminal group 11a.

The plurality of input terminals Imp are designated as input terminals Imp1, Imp2, ..., Imp21 in order from the top of the figure. The first sense wiring group SWG1 is connected to the input terminals Imp1 to Imp10 in order from the smallest number, the third side wiring DRW3 is connected to the input terminal Imp11, and the second sense wiring group SWG2 is connected from the smallest number. They are connected to the input terminals Imp12 to Imp21 in order.

The state of FIG. 6A in which the switch 11b selects the upper input terminal is referred to as the first phase, and the state of FIG. 6B in which the switch 11b selects the lower input terminal is the first phase. It will be referred to as two phases.

In the first phase shown in FIG. 6A, the combinations of signals input to the differential amplifiers 12a1 to 12a5 via the input terminal group 11a, the switch 11b, and the output terminal group 11c are (SL0, SL2), respectively. , (SL4, SL6), (SL8, SL10), (SL12, SL14), (SL16, SL18), and the combinations of signals input to the differential amplifiers 12a6 to 12a10 are (DRSL, SL1), (DRSL, SL1), respectively. SL3, SL5), (SL7, SL9), (SL11, SL13), (SL15, SL17).

On the other hand, in the second phase shown in FIG. 6B, the combinations of signals input to the differential amplifiers 12a1 to 12a5 via the input terminal group 11a, the switch 11b, and the output terminal group 11c are each (SL2, SL4), (SL6, SL8), (SL10, SL12), (SL14, SL16), (SL18, DRSL), and the combinations of signals input to the differential amplifiers 12a6 to 12a10 are (SL1, SL3), respectively. , (SL5, SL7), (SL9, SL11), (SL13, SL15), (SL17, SL19).

As described above, in the touch panel system 1c of the present embodiment, in both the first phase and the second phase, the first sense line SLF of the first sense line group SLG1 and the second sense line SLS of the second sense line group SLG2 Is never input to the same differential amplifier 12a. In other words, the even-numbered set of sense lines SL and the odd-numbered set of sense lines SL on the touch panel 3 are not input to the same differential amplifier 12a.

Therefore, even if the configuration is such that the sense wiring SW is alternately pulled out from both sides of the touch panel 3, the following effects are obtained. That is, when the subtraction unit 12 executes the difference signal processing, the difference between the signal from the double-sided sense line DRSL and the signal from the second sense line SLS (sense line SL19) adjacent to the double-sided sense line DRSL, and the double-sided sense. When the difference between the signal from the line DRSL and the signal from the first sense line SLS (sense line SL1) is calculated, the phenomenon that the noise removal effect is reduced due to the difference in the wiring path is suppressed. be able to.

Therefore, it is possible to suppress the reduction of the noise removal effect while narrowing the frame area.

[Summary]
In the touch panel system according to the first aspect of the present invention, the M first sense line SLF, the N second sense lines SLS, and the L bilateral wiring sense lines (both sides of M and N) arranged on the touch panel 3 are provided. It satisfies K differential input amplification circuits (differential amplifier 12a) and (K is (M + N + L) = (2K + 1)) for amplifying the difference between the signals from the sense line DRSL (L is an integer of 1 or more). Integer), M first wiring (first sense wiring SWF) corresponding to the M first sense line, L double-sided wiring DRW corresponding to the L double-sided wiring sense line, and the N It corresponds to (M + L + N) input terminals Imp to which N second wirings (second sense wiring SWS) corresponding to the second sense line of the book are connected, and the K differential input amplification circuits. A switching circuit (phase switching unit 11) having 2 × K) output terminals Out is provided, and the first wiring of the M wires is connected to the input terminals arranged from the first to the Mth, and the L wires are connected. Both side wiring DRW is connected to the input terminal arranged from the (M + 1) th to the (M + L) th, and the N second wiring is connected to the input terminal arranged from the (M + L + 1) th to the (M + L + N) th. It is characterized by that.

According to the above configuration, in the case where the first wiring and the second wiring are pulled out from the left and right sides of the touch panel in order to narrow the frame area around the touch panel, the wirings on both sides are the same as the first wiring and the second wiring. Both wiring path components can be included. In this case, when the difference between the signal from the two-sided wiring sense line and the signal from the first sense line and the second sense line are calculated respectively, the phenomenon that the noise removal effect is reduced due to the difference in the wiring path occurs. Can be suppressed.

Therefore, it is possible to provide a touch panel system capable of suppressing a decrease in the effect of noise removal when the frame area is narrowed.

In the touch panel system according to the second aspect of the present invention, in the touch panel system according to the first aspect, the first sense line is drawn out from the touch panel 3 along the first direction and connected to the first wiring, and the second sense line is formed. It is configured to be pulled out from the touch panel 3 along a second direction opposite to the first direction and connected to the second wiring.

According to the above configuration, the frame area around the touch panel can be narrowed, and the area of the touch panel can be widened.

The touch panel system according to the third aspect of the present invention is the first touch panel system according to the second aspect, wherein the bilateral wiring DRW is pulled out from the touch panel 3 along the first direction and extends along a path along the first wiring. The route wiring (first double-sided wiring DRW1) and the second route wiring (second double-sided wiring DRW2) drawn from the touch panel 3 along the second direction and extending along the path along the second wiring merge. The configuration is provided with a wiring merging portion 40 for wiring.

According to the above configuration, the bilateral wiring is configured to include both wiring path components of the first wiring and the second wiring. Therefore, when the difference between the signal from the two-sided wiring sense line and the signal from the first sense line and the second sense line are calculated respectively, the phenomenon that the noise removal effect is reduced due to the difference in the wiring path occurs. Can be suppressed.

Therefore, it is possible to provide a touch panel system capable of suppressing a decrease in the effect of noise removal while narrowing the frame area.

The electronic device according to the fourth aspect of the present invention is characterized by including the touch panel system according to any one of the first to third aspects.

According to the above configuration, it is possible to provide an electronic device provided with a touch panel system capable of suppressing a reduction in the effect of noise removal while narrowing the frame area of the display unit.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

1a to 1c Touch panel system 3 Touch panel 11 Phase switching unit (switching circuit)
11a Input terminal group 11c Output terminal group 12a Differential amplifier (differential input amplifier circuit)
40 Wiring confluence DRSL Both sides sense line (both sides wiring sense line)
DRW double-sided wiring DRW1 1st double-sided wiring (1st route wiring)
DRW2 2nd side wiring (2nd route wiring)
SLF 1st sense line SLS 2nd sense line SWF 1st sense wiring (1st wiring)
SWS 2nd sense wiring (2nd wiring)
Imp1 to Imp21 input terminal

Claims (4)

The difference between the signals from the M first sense line, the N second sense lines, and the L double-sided wiring sense lines (L is an integer of 1 or more) arranged on the touch panel. K differential input amplifier circuits to amplify (K is an integer satisfying (M + N + L) = (2K + 1)),
M first wiring corresponding to the M first sense line, L double-sided wiring corresponding to the L double-sided wiring, and N corresponding to the N second sense line. A switching circuit having (M + L + N) input terminals to which the second wiring of the above is connected and (2 × K) output terminals corresponding to the K differential input amplifier circuits is provided.
The first M wires are connected to the input terminals arranged from the 1st to the Mth, and both side wirings of the L wires are connected to the input terminals arranged from the (M + 1) th to the (M + L) th. A touch panel system characterized in that N second wires are connected to input terminals arranged from (M + L + 1) th to (M + L + N) th. The first sense line is pulled out from the touch panel along the first direction and connected to the first wiring.
The touch panel system according to claim 1, wherein the second sense line is drawn out from the touch panel along a second direction opposite to the first direction and connected to the second wiring. The bilateral wiring is drawn from the touch panel along the first direction and extends from the touch panel along the first wiring, and is drawn from the touch panel along the second direction. The touch panel system according to claim 2, further comprising a wiring merging portion where the second route wiring extending along the route along the two wirings merges. An electronic device comprising the touch panel system according to any one of claims 1 to 3.

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