JP6208314B2 - Touch panel and display device - Google Patents

Description

  The present invention relates to a touch panel and a display device, and more particularly, to a projected capacitive touch panel and a display device including the same.

  A touch panel that detects a touch by a human finger or the like on a touch screen and specifies the position coordinates of the touched position is an excellent user interface.

  The projected capacitive method, which is one of the capacitive methods, uses a detection circuit to detect a slight change that the capacitance of a human finger gives to the touch sensor provided in the touch screen. The position coordinates in the touch screen are calculated. Touch detection is possible even when the front side of the touch screen in which the touch sensor is built is covered with a protective plate such as a glass plate having a thickness of about several millimeters.

  Since the protective plate can be disposed on the front surface, it has excellent ruggedness, can detect touch even when wearing gloves, and has a long life because there are no moving parts.

  The protective plate of the projected capacitive touch panel is made of a transparent resin substrate such as acrylic or polycarbonate, a glass substrate, or the like. And, when the outer size of the touch surface for inputting position information with a pointer such as a finger is made larger than the sensor surface for detecting the capacitance and the sensor surface is overhanged and covered, the design is improved. In addition to providing excellent products, it also excels in sealing when combined with a display device casing.

  For this reason, it can be used in places where rain, seawater, drinks, chemicals, etc., which cannot be used with conventional touch panels such as resistive film systems, can be detected with high sensitivity even when wearing gloves. On the other hand, there is a need for a touch panel that operates stably without erroneous detection even when moisture adheres.

  As an optimal touch panel for a waterproof specification device, for example, Patent Document 1 discloses a configuration that emphasizes waterproofness applicable to a mobile communication terminal or the like.

JP 2009-276821 A

  The touch panel disclosed in Patent Document 1 covers the opening of the housing with a protective panel and is waterproof. However, a predetermined space is provided between the protective panel and the detection unit of the display device in the housing. The touch panel is touched with a finger or the like, the protective panel is bent, and the position where the capacitance changes due to the change in the predetermined interval is detected to identify the touched position.

  As described above, the touch panel disclosed in Patent Document 1 is configured on the assumption that the protective panel is bent, and has a problem in terms of robustness.

  In addition, a surface-type capacitive coupling touch panel, which is one of the capacitive methods, is a touch panel that has been used conventionally, and a sensor electrode is formed on a glass substrate surface with a transparent wiring material such as indium tin oxide (ITO). It has a formed structure.

  For this reason, even if moisture adheres to the sensor surface, if the adhered moisture is not grounded via a finger or the like, it is not detected as a touch and is not erroneously detected. This is because the sensor electrode of the touch panel is formed on the entire glass surface and becomes a single sensor on the entire display surface, so that a substance having a very high relative dielectric constant such as water (relative dielectric constant of about 80) is present on the sensor surface. Even if it adheres, the electric potential which couple | bonds through water becomes the same electric potential. Therefore, the change in capacity due to water adhesion as viewed from the detection circuit side is very small relative to the change in capacity at the time of input by fingers or the like, and as a result, it is not detected as an input.

  However, since it has a configuration in which the wiring for applying an electric field uniformly to the sensor surface is formed around the touch panel substrate using silver wiring, etc., it is inferior in robustness and design compared to the projected capacitance method In addition, there is a problem that, in principle, simultaneous multipoint detection and detection through gloves cannot be performed, so that the usage is limited.

  On the other hand, the projected capacitive touch panel employs a configuration having a plurality of sensor electrodes arranged on the panel surface, and a self-capacitance method for measuring the capacitance of a plurality of sensor electrodes in units of sensor electrodes, or one sensor electrode. Various capacitance detection means have been developed, such as a mutual capacitance method in which an AC signal is input from the other sensor electrode and the capacitance is detected from the other sensor electrode, and has the feature that simultaneous multipoint detection and detection through gloves are possible.

  However, since it has a high-sensitivity detection circuit that can generally detect the capacitance of the indicator through the protective panel, it is a detection method that generates a potential difference between the sensor electrode to be measured and the surrounding wiring. In the touch panel, there is a capacitance change that occurs when a substance having a very high relative dielectric constant such as water (relative dielectric constant of about 80) adheres to the sensor region, and a capacitance change that occurs when an indicator such as a finger touches. There is a problem of misdetection that even if a water droplet or the like adheres without being distinguished, it is recognized as a touch.

  In order to suppress such erroneous detection of the touch panel, it is desirable to use a capacitance detection means that makes the sensor surface have the same potential so that the capacitance change due to moisture adhesion in the sensor surface is minimized. However, when water droplets or the like adhere across the sensor region and the peripheral region where the sensor is not formed, the electrostatic capacity coupled to the frame of the image display module and the device housing is connected via the protection panel and the water droplets. Since it appears as an electrostatic capacity on the sensor of the touch panel, there is a problem that even if the capacity detection means is devised, it cannot be distinguished from a change in capacity due to an indicator such as a finger, resulting in erroneous detection of the touch panel.

  The present invention has been made in order to solve the above-described problems, and has a robust touch panel that suppresses false detection even when water droplets or the like adhere to it, and has a touch panel suitable for waterproof specifications. It is an object to provide a display device.

  An aspect of the touch panel according to the present invention includes a touch screen substrate on which a plurality of capacitance detection wirings are disposed, a transparent substrate that is disposed so as to overlap with the touch screen substrate, and whose indicator is in contact with one main surface thereof. , Detecting a change in capacitance between the indicator and the plurality of capacitance detection wires when the indicator contacts the transparent substrate, and the indicator on the transparent substrate is detected. A capacitance detection circuit for detecting a contact position, wherein the transparent substrate has an additional electrode in a region that does not overlap a sensor effective region of the touch screen substrate, and the capacitance detection circuit includes the plurality of electrostatic capacitance detection circuits. Among the capacitance detection wirings, an AC signal is supplied to the additional electrode so that a potential difference between the capacitance detection wiring not used for detecting a change in capacitance due to contact with the indicator and the additional electrode is minimized. give.

  According to the touch panel of the present invention, the transparent electrode has an additional electrode in a region that does not overlap the sensor effective region of the touch screen substrate, and the capacitance detection circuit is an indicator among the plurality of capacitance detection wires. An AC signal is applied to the additional electrode so that the potential difference between the capacitance detection wiring not used for detecting the capacitance change due to contact with the additional electrode and the additional electrode is minimized. The capacitance detection circuit does not detect a change in capacitance on the touch panel when attached across the peripheral area, can suppress erroneous detection, and can provide a touch panel suitable for waterproof specification. . Since the indicator contacts the transparent substrate, a touch panel with improved robustness can be provided.

It is a figure which shows the whole structure of the display apparatus provided with the touchscreen of embodiment which concerns on this invention. It is sectional drawing of the display apparatus provided with the touchscreen of embodiment which concerns on this invention. It is a figure which shows typically the structure of the display apparatus provided with the touchscreen of embodiment which concerns on this invention. It is a fragmentary sectional view of a display provided with a touch panel of an embodiment concerning the present invention. It is a figure explaining the method to specify the position coordinate of the indicator in the touchscreen of embodiment which concerns on this invention. It is a fragmentary sectional view of the display apparatus provided with the touch panel which does not apply this invention. It is a figure explaining the method of specifying the position coordinate of the indicator in the touch panel which does not apply this invention. It is a figure which shows typically the structure of the display apparatus provided with the touchscreen of the modification 1 of embodiment which concerns on this invention. It is sectional drawing of the display apparatus provided with the touch panel of the modification 1 of embodiment which concerns on this invention. It is sectional drawing of the display apparatus provided with the touchscreen of the modification 2 of embodiment which concerns on this invention. It is sectional drawing of the display apparatus provided with the touchscreen of the modification 3 of embodiment which concerns on this invention. It is sectional drawing of the display apparatus provided with the touchscreen of the modification 4 of embodiment which concerns on this invention.

<Embodiment>
<Device configuration>
FIG. 1 is a plan view showing an overall configuration of a display device DP1 including a touch panel TP1 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA in FIG.

  As shown in FIG. 1 and FIG. 2, the touch panel TP1 has a transparent electrode such as ITO (indium tin oxide) on a transparent substrate 101 (hereinafter referred to as a touch screen substrate) made of glass, PET (polyethylene terephthalate), or the like. The transparent substrate 201 covers the touch screen 100 on which the touch panel detection sensor wiring 102 (capacitance detection wiring) formed in a wiring shape capable of effectively transmitting light with a material, ultra-fine metal wiring, or the like is formed. It has a configuration. In FIG. 2, the touch panel detection sensor wiring 102 is shown only in one direction, but the touch panel detection sensor wiring 102 is also arranged in a direction orthogonal thereto. This arrangement is not shown, and both arrangements are insulated by an insulating film, but the insulating film is also not shown.

  In FIG. 1, an area where the touch panel detection sensor wiring 102 is formed is surrounded by a broken line, and the area is referred to as a touch sensor area SR.

  A touch panel controller 901 is electrically connected to the touch panel detection sensor wiring 102 via a connection board 903 (hereinafter referred to as FPC) such as an FPC (Flexible Printed Circuit), and the touch panel controller 901 has a touch panel detection sensor. A capacitance detection circuit 902 for detecting a change in capacitance in the wiring 102 is mounted.

  The touch screen 100 can detect a change in electrostatic capacitance due to an indicator 702 such as a finger alone, but for reasons such as improved robustness and design (design) when incorporated in a system. The transparent substrate 201 (hereinafter referred to as a protective plate) is disposed so as to cover the surface (touch surface) that the indicator touches.

  FIG. 1 shows a state in which a high dielectric constant material 701 having a high relative dielectric constant such as water, salt water, and chemicals adheres to the protective plate 201, and the high dielectric constant material 701 includes the touch sensor region SR, the liquid crystal display module, and the like. The display device 401 is attached at a position corresponding to the upper part of the frame.

  As the protective plate 201, a transparent substrate such as a transparent resin substrate such as acrylic or polycarbonate is used in addition to a glass substrate, and a material having lightness and light transmittance is used. Note that the touch screen 100 and the protective plate 201 are attached to each other with a transparent adhesive material 301.

  As shown in FIG. 2, an additional electrode 202 is formed on the peripheral portion (the portion where the touch sensor region SR and the protective plate 201 do not overlap) of the main surface (back surface) opposite to the touch surface of the protective plate 201. Yes.

  The additional electrode 202 is formed of a light-shielding material in consideration of design (designability) when incorporated in the system, and the sensor lead-out wiring 103 of the touch screen 100 and the frame of the display device 401 which will be described later. By making 404 or the like invisible from the touch surface side, the design can be improved.

  In FIG. 1, the portion where the additional electrode 202 is arranged is shown with hatching. The additional electrode 202 may have a multilayer structure so that the surface on the touch surface side has a light shielding property.

  The additional electrode 202 is electrically and mechanically connected to the sensor lead wire 103 disposed on the touch screen substrate 101 by a conductive material 204 such as silver paste, and is electrically connected to the touch panel controller 901 via the FPC 903. Is done. The conductive material 204 may be provided continuously over the entire periphery of the edge of the touch screen substrate 101, or may be provided so as to come into multi-point contact with the touch screen substrate 101, or only one point. You may provide so that it may contact.

  In addition, since the additional electrode 202 is disposed on the back surface opposite to the front surface with which the indicator or the like of the protective plate 201 contacts, it becomes possible to prevent the electrode surface from being deteriorated due to something in contact with the additional electrode 202. . If the additional electrode 202 is covered with a protective film or the like, the additional electrode 202 can be disposed on the front surface of the protective plate 201.

  By adopting a configuration in which the outer shape of the protection plate 201 is larger (overhanging) than the outer shape of the display device 401, the waterproof property can be improved.

  Note that the outer shape of the protective plate 201 may be smaller than the outer shape of the display device 401 as long as the touch screen 100 can be covered.

  The touch panel controller 901 detects an electrostatic capacitance formed between the touch screen 100 and an indicator 702 such as a finger or an electrostatic stylus by an electrostatic capacitance detection circuit 902, and based on the detection result, the indicator The detection processing circuit (not shown) performs processing for calculating the presence / absence of touch and the coordinates of the touch position, and outputs the information to an external device (such as a computer).

  The touch panel TP1 is used in combination with a display device 401 constituting a GUI (Graphical User Interface) device, and is displayed on the main surface opposite to the main surface covered with the transparent substrate 201 of the touch screen 100. A device 401 is provided.

  The display device 401 is, for example, a liquid crystal display module. A TFT (thin film transistor) substrate 402a and a color filter substrate 402b are stacked, and polarizing plates 402c are attached to both main surfaces of the stacked body. It is composed. A backlight 403 is provided on the opposite side of the video display substrate 402 from the video display surface.

  In these configurations, the backlight 403 is housed in the bottomed and uncovered casing 405 so that the bottom surface is located, and the bowl-shaped frame 404 is covered from the opening side of the casing 405 so as to cover the casing 405. ing. The frame 404 has an opening corresponding to the video display surface of the video display substrate 402.

  For example, a double-sided tape 501 is attached around the opening of the frame 404 of the display device 401, and the main surface of the touch screen substrate 101 of the touch screen 100 is in contact with one adhesive surface of the double-sided tape 501. And the display device 401 are connected.

  In addition, in order to improve display visibility outdoors (the air layer is eliminated to suppress interface reflection) and to prevent condensation, the display device 401 and the touch screen 100 are connected using a transparent adhesive instead of the double-sided tape 501. It is good also as a structure.

  In the above description, the display device 401 is a liquid crystal display module as an example, but may be an organic EL display or other display devices.

  FIG. 3 is a diagram schematically showing the configuration of the touch panel TP1 and the display device DP1 according to the present embodiment, created based on the overall plan view and cross-sectional view described in FIGS.

  In FIG. 3, matrix wiring is provided in the touch sensor region SR with four X-directional wirings X0, X1, X2, and X3 and four Y-directional wirings Y0, Y1, Y2, and Y3 orthogonal to the X-directional wiring. The structure formed is shown. The touch panel detection sensor wiring 102 constitutes these X-direction wiring and Y-direction wiring.

  A sensor lead wire 103 is connected to each of the X direction wires X0 to X3 and the Y direction wires Y0 to X3, and the sensor lead wire 103 passes under the additional electrode 202 and further passes through the FPC 903 and is electrostatically connected to the touch panel controller 901. A configuration connected to the capacitance detection circuit 902 is shown. The sensor lead-out wiring 103 is hidden from the additional electrode 202 and cannot be seen from the touch surface side, but is shown for convenience in FIG.

  A wiring 905 for electrically connecting the additional electrode 202 disposed on the back surface of the protective plate 201 and the touch panel controller 901 is shown. The wiring 905 is connected to the output of the drive circuit 904 via the FPC 903. ing. The drive circuit 904 is configured by a buffer or the like, and is a circuit added according to the parasitic capacitance load of the additional electrode 202. Note that the input of the drive circuit 904 is connected to the capacitance detection circuit 902.

  The wiring 905 is connected to a part of the conductive material 204 that electrically connects the additional electrode 202 and the electrode disposed on the touch screen substrate 101, and the connection portion is shown as a connection portion 204a. Note that the connection portion 204a is hidden behind the additional electrode 202 and cannot be seen from the touch surface side, but is shown for convenience in FIG.

<Operation and effect>
Next, operations and effects of the touch panel TP1 according to the embodiment of the present invention will be described with reference to FIGS.

  4 is a cross-sectional view showing in detail a part of the edge portion of the cross-sectional view of FIG. In FIG. 4, a system main body housing 601 in which the display device DP1 is incorporated, and parasitic capacitors 801 and 805 coupled to the high dielectric constant material 701 are illustrated.

  Further, as shown in FIG. 4, in the additional electrode 202, a region facing the housing 405 and the housing 601 of the system main body in the portion facing the display device 401 is covered with the insulating layer 203.

  The parasitic capacitance 801 is a parasitic capacitance between the high dielectric constant material 701 and the touch panel detection sensor wiring 102, and the parasitic capacitance 805 is a parasitic capacitance between the high dielectric constant material 701 and the additional electrode 202.

  FIG. 5 is a diagram for explaining a method of specifying the position coordinates of the indicator using the schematic diagram of the touch panel TP1 shown in FIG. 3, and the capacitance detection in each of the X direction wirings X0 to X3. An example of the level and an example of the capacitance detection level in each of the Y-direction wirings Y0 to Y33 are shown together.

  FIG. 6 is a cross-sectional view showing the configuration of the touch panel TP10 when the additional electrode 202 shown for comparison with FIG. 4 is not provided. FIG. 7 is a diagram for explaining a problem in the case where the position coordinates of the indicator are specified in a configuration in which the additional electrode 202 is not provided, and an example of the capacitance detection level in each of the X-direction wirings X0 to X3. FIG. 6 also shows an example of the capacitance detection level in each of the Y-direction wirings Y0 to Y33.

  The touch panel TP10 shown in FIG. 6 is the same as the touch panel TP1 shown in FIG. 4 except that it does not have the additional electrode 202 on the back surface of the protective plate 201 and does not have the conductive material 204. Parasitic capacitances 801, 802, and 803 are included as parasitic capacitances coupled to the rate substance 701.

  The parasitic capacitance 802 is a parasitic capacitance between the high dielectric constant material 701 and the frame 404, and the parasitic capacitance 803 is a parasitic capacitance between the high dielectric constant material 701 and the housing 601.

  5 and 7, among the four X-direction wirings X0, X1, X2, and X3 and the four Y-direction wirings Y0, Y1, Y2, and Y3 arranged in the touch sensor region SR, It shows that the indicator 702 is touched over the protective plate at the intersection of the X-direction wiring X2 and the Y-direction wiring Y1.

  5 and 7, the high dielectric constant material 701 such as water is passed through the protective plate from the vicinity of the intersection of the X-direction wiring X0 and the Y-direction wiring Y1 and from the vicinity of the intersection of the X-direction wiring X0 and the Y-direction wiring Y2. It shows that the sensor wiring 102 for touch panel detection is attached so as to straddle the region outside.

  5 and 7, when the high dielectric constant material 701 is not attached, the X-direction wiring X2 and the Y-direction are caused by the capacitance coupled between the indicator 702 and the touch panel detection sensor wiring 102. When the capacitance detection level of the wiring Y1 (when there is no input by the indicator as a base line and the difference from the base line) is equal to or higher than a predetermined touch threshold value, the touch panel controller 901 detects that and the instruction in the touch screen Body position coordinates are identified.

  In this operation, the reason why erroneous detection occurs when a water droplet or the like adheres will be described with reference to FIG.

  In the configuration without the additional electrode 202 as shown in FIG. 6, when the high dielectric constant material 701 adheres to the protective plate 201, the high dielectric constant material 701 is attached to the frame region of the housing 405 of the display device 401 or the housing of the system main body. Since it extends to the upper region of the body 601, the touch panel controller 901 detects the electrostatic capacitance of the touch panel detection sensor wiring 102 (X-direction wiring X2) in which the high dielectric constant material 701 exists, and at the same time, the parasitic capacitance 801. , 802 and 803 are also detected. As a result, as shown in FIG. 7, the capacitance detection level exceeds the touch threshold value in the X direction wirings X0 and X2 and the Y direction wirings Y1 and Y2, and the vicinity of the intersection of the X direction wiring X0 and the Y direction wiring Y1 and It is recognized that the vicinity of the intersection of the X-direction wiring X0 and the Y-direction wiring Y2 is touched, leading to erroneous detection.

  On the other hand, in the touch panel TP1 according to the present invention, erroneous detection can be suppressed even when water droplets adhere. The reason for this will be described with reference to FIGS.

  The touch panel controller 901 shown in FIG. 3 receives the detection signal detected by the touch panel detection sensor wiring 102 by the high-capacitance capacitance detection circuit 902 having a low capacitance so as not to affect the detection signal. The capacitance detection circuit 902 includes a touch panel detection sensor wiring 102 not used for detection, a touch panel detection sensor wiring 102 used for detection, and an additional electrode 202 formed on the back surface of the protection plate 201. An AC signal is applied via the drive circuit 904 so that the potential difference between the two is minimized.

  The drive circuit 904 includes a buffer circuit having a low circuit delay, a high slew rate, and a low impedance output.

  By adopting such a configuration, the potential difference between the additional electrode 202 and the touch-panel detection sensor wiring 102 being detected is reduced, and the parasitic capacitance 802 and the high dielectric constant between the high dielectric constant material 701 and the housing 405 are reduced. When the parasitic capacitance 803 between the rate substance 701 and the housing 601 is substantially eliminated, the capacitance detection levels of the X-direction wiring X0 and the Y-direction wiring Y2 do not exceed the touch threshold value, and water droplets adhere However, false detection can be suppressed.

  The additional electrode 202 is covered with the insulating layer 203 except for the connection portion 204a that is electrically connected to the touch panel controller 901. The additional electrode 202 is provided on the touch panel controller 901 by contact with the housing 601 or the housing 405 due to twisting or the like. In addition, it is possible to prevent a problem from occurring in the output circuit of the drive circuit 904.

  As described above, in the touch panel TP1 according to the present invention, the additional electrode 202 is formed on the back surface of the protective plate 201 in a portion where the touch sensor region SR of the touch screen 100 and the protective plate 201 do not overlap with each other. The drive circuit is electrically connected to the capacitance detection circuit 902 so that the potential difference between the touch panel detection sensor wiring 102 and the additional electrode 202 whose capacitance is to be detected by the capacitance detection circuit 902 is minimized. An AC signal is applied from 904 to the additional electrode 202. Thereby, even when a high dielectric constant material 701 such as water adheres to the touch surface of the touch panel TP1, erroneous detection can be suppressed, and a highly robust touch panel and display device can be realized.

  As shown in FIG. 2, the sensor lead-out wiring 103 and the additional electrode 202 are all covered with the transparent adhesive material 301 except for the terminal portion connected by the FPC.

  Sensitive detection due to the use of protective plate 201 with increased thickness to increase robustness, and the use of polycarbonate which is a material that is hard to break but has a lower dielectric constant than glass (dielectric constant about 3) and through gloves When the circuit is used, the parasitic capacitance value of the sensor lead-out wiring 103, the parasitic capacitance balance between adjacent wirings, and the like greatly affect the touch panel performance.

  In the present invention, the sensor lead-out wiring 103 and the additional electrode 202 are all covered with a transparent adhesive material 301 (dielectric constant of about 3 to 5), which is a material having a higher dielectric constant than air (dielectric constant of about 1), and added from the touch panel controller 901. An AC signal is applied from the drive circuit 904 to the additional electrode 202 to the additional electrode 202 so that the potential difference between the electrode 202 and the touch-panel detection sensor wiring 102 being detected is minimized.

  Thereby, the parasitic capacitance of the sensor lead-out wiring 103 can be minimized, and the parasitic capacitance balance between adjacent wirings of the sensor lead-out wiring 103 can be minimized, and a highly sensitive touch panel and display device can be obtained.

  Further, since the additional electrode 202 covers the upper side of the sensor lead-out wiring 103, it is possible to prevent a decrease in position coordinate accuracy and false detection due to noise from disturbances, etc., and to reduce the parasitic capacitance of the sensor lead-out wiring 103 and to reduce the wiring length difference. The capacity difference due to can be reduced.

<Modification 1>
FIG. 8 is a plan view schematically showing a configuration of a display device DP2 provided with the touch panel TP2 of the first modification of the embodiment according to the present invention, and FIG. 9 is a part of the edge portion as in FIG. FIG. 5 is a cross-sectional view showing in detail, the same components as those of the touch panel TP1 and the display device DP1 shown in FIGS.

  As shown in FIGS. 8 and 9, in the touch panel TP <b> 2, the edge of the touch screen substrate 101 where the sensor lead-out wiring 103 is not provided is made of the same material as the sensor lead-out wiring 103 and has the same manufacturing process. 103b is formed. In FIG. 8, the sensor lead-out wiring 103 and the electrode 103b are hidden by the additional electrode 202 and are not visible from the touch surface side, but are shown for convenience.

  As shown in FIG. 9, the additional electrode 202 formed on the protective plate 201 and the electrode 103b are connected by capacitive coupling through the transparent adhesive material 301, and are conductive materials such as the touch panel TP1. The configuration 204 is not used.

  For this reason, the touch panel controller 901 and the additional electrode 202 are coupled by capacitive coupling. However, by omitting the formation of the conductive material 204, the cost in the manufacturing process can be reduced. Formation defects do not occur, and the reliability of electrical connection can be improved.

<Modification 2>
FIG. 10 is a cross-sectional view illustrating a configuration of a display device DP3 including a touch panel TP3 according to a second modification of the embodiment of the present invention, which is the same as the touch panel TP1 and the display device DP1 illustrated in FIGS. The same reference numerals are given to the configurations, and duplicate descriptions are omitted.

  As shown in FIG. 10, in the touch panel TP3, a touch panel detection sensor wiring is also formed on the back surface of the protective plate 201, and this wiring is used as the touch panel detection sensor wiring 102b. Further, the touch panel detection sensor wiring formed on the touch screen substrate 101 is referred to as touch panel detection sensor wiring 102a.

  By forming the touch panel detection sensor wiring 102b on the protective plate 201, the protective plate 201 also serves as a touch screen substrate.

  Here, when the touch screen substrate 101 is referred to as a first touch screen substrate and the protective plate 201 is referred to as a second touch screen substrate, the touch panel detection sensor wiring 102a on the first touch screen substrate and the second touch screen are referred to as the second touch screen substrate. Since the touch panel detection sensor wiring 102b on the substrate is bonded with the transparent adhesive material 301, the connection between the wirings is compared to the case where all the touch panel detection sensor wiring is formed on one touch screen substrate. Capacity can be reduced.

  Note that the touch panel detection sensor wiring 102 a of the first touch screen substrate and the touch panel detection sensor wiring 102 b of the second touch screen substrate are both electrically connected to the outside by the sensor lead-out wiring 103. The FPC 903 connected to the touch panel controller 901 is connected to the touch panel detection sensor wiring 102a of the first touch screen substrate and the touch panel detection sensor wiring 102b of the second touch screen substrate via the sensor lead wiring 103, respectively. ing.

  Although the additional electrode 202 is provided on the back surface of the protection plate 201, it is not provided in the formation region of the sensor lead-out wiring 103 on the back surface of the protection plate 201. Thereby, the protection plate 201 does not interfere with the function of the sensor lead-out wiring 103.

<Modification 3>
FIG. 11 is a cross-sectional view showing a configuration of a display device DP4 provided with a touch panel TP4 of a third modification of the embodiment according to the present invention, which is the same as the touch panel TP1 and the display device DP1 shown in FIGS. The same reference numerals are given to the configurations, and duplicate descriptions are omitted.

  As shown in FIG. 11, in the touch panel TP4, the touch screen substrate 101 is used instead of the protective plate 201, and the peripheral portion (sensor effective region and touch screen substrate 101) of the main surface (back surface) opposite to the touch surface is used. An additional electrode 202 is formed on a portion where the electrode does not overlap. For this reason, the touch screen substrate 101 is configured to have the same thickness as the protective plate 201.

  The additional electrode 202 is directly connected to the FPC 903 in the same manner as the sensor lead-out wiring 103, and the conductive material 204 is unnecessary, but the sensor lead-out wiring 103 (not shown) is also formed on the back surface of the touch screen substrate 101. Therefore, the additional electrode 202 is not formed in the region where the sensor lead-out wiring 103 is formed.

  A sensor effective area is provided on the back surface of the touch screen substrate 101, and touch panel detection sensor wirings 102 are formed in a matrix to form the touch screen 100.

  The touch screen substrate 101 is mounted on the display device 401 so that the back surface is on the display device 401 side, and the touch screen 100 and the display device 401 are attached by a double-sided tape 501 attached around the opening of the frame 404 of the display device 401. Are connected to each other.

  By using the touch screen substrate 101 in place of the protective plate 201 and the indicator touching the touch screen substrate 101, there is no need to provide the protective plate 201, the number of components can be reduced, and cost reduction can be promoted. At the same time, the touch panel can be made thinner and lighter.

<Modification 4>
FIG. 12 is a cross-sectional view showing a configuration of a display device DP5 including a touch panel TP5 according to a fourth modification of the embodiment of the present invention, which is the same as the touch panel TP1 and the display device DP1 shown in FIGS. The same reference numerals are given to the configurations, and duplicate descriptions are omitted.

  As shown in FIG. 12, in the touch panel TP5, the touch panel detection sensor wirings 102 are formed in a matrix on the color filter substrate 402d, and the color filter substrate 402d also serves as a touch screen substrate.

  A polarizing plate 402c is attached on the color filter substrate 402d to constitute an image display substrate 402.

  The touch sensor area where the touch panel detection sensor wiring 102 is disposed is provided so as to face the opening of the frame 404. A protective plate 201 is provided so as to cover the display device 401, and the display device 401 and the protective plate 201 are attached by a transparent adhesive material 301.

  An additional electrode 202 is formed on the periphery of the back surface of the protective plate 201. The additional electrode 202 is an upper surface plate 404a that defines an opening of the frame 404 of the display device 401 with a conductive material 204 such as silver paste. It is electrically and mechanically connected to the potential fixing wiring 103a provided above. The potential fixing wiring 103a is provided from the upper surface plate 404a to the back side of the upper surface plate 404a. An FPC 903 is disposed on the inner surface of the side plate 404b of the frame 404. Each wiring of the FPC 903 is connected to the touch panel detection sensor wiring 102 provided on the color filter substrate 402d, and the side plate 404b It is also connected to a potential fixing wiring 103a provided on the inner surface.

  By using the color filter substrate 402d as a touch screen substrate, the touch screen substrate becomes unnecessary, the number of components can be reduced, cost reduction can be promoted, and the touch panel can be made thinner and lighter.

  It should be noted that the present invention can be freely combined with the embodiments and modifications within the scope of the invention, and the embodiments and modifications can be appropriately modified and omitted.

  DESCRIPTION OF SYMBOLS 100 Touchscreen, 102 Touchscreen detection sensor wiring, 103 Sensor lead-out wiring, 201 Protection board, 202 Additional electrode, 401 Display device, 402 Image display board, 901 Touchscreen controller.

Claims (15)

A touch screen substrate on which a plurality of capacitance detection wirings are disposed;
A transparent substrate that is arranged to overlap with the touch screen substrate, and whose indicator is in contact with one main surface thereof;
When the indicator is in contact with the transparent substrate, a change in capacitance between the indicator and the plurality of capacitance detection wirings is detected, and the indicator contacts on the transparent substrate. A capacitance detection circuit for detecting a position;
The transparent substrate is
Having an additional electrode in a region that does not overlap the sensor effective region of the touch screen substrate;
The capacitance detection circuit is
Among the plurality of capacitance detection wires,
A touch panel that provides an AC signal to the additional electrode so that a potential difference between a capacitance detection wiring not used for detecting a change in capacitance due to contact of the indicator and the additional electrode is minimized. A touch screen substrate in which an indicator is in contact with one main surface, and a plurality of capacitance detection wirings are disposed on the other main surface opposite to the one main surface;
When the indicator contacts the touch screen substrate, a change in capacitance between the indicator and the plurality of capacitance detection wirings is detected, and the indicator on the touch screen substrate is detected. A capacitance detection circuit for detecting the contact position of
The touch screen substrate is
Having an additional electrode in a region other than the sensor effective region of the touch screen substrate;
The capacitance detection circuit is
Among the plurality of capacitance detection wires,
A touch panel that provides an AC signal to the additional electrode so that a potential difference between a capacitance detection wiring not used for detecting a change in capacitance due to contact of the indicator and the additional electrode is minimized. The additional electrode is
Arranged on the other main surface opposite to the one main surface of the transparent substrate,
The touch panel according to claim 1, wherein the plurality of capacitance detection wirings are arranged on a main surface of the touch screen substrate on a side facing the other main surface of the transparent substrate. The touch screen substrate is
A lead wire disposed on the main surface and connecting the plurality of capacitance detection wires to the outside;
The additional electrode is
The touch panel as set forth in claim 3, wherein the touch panel is disposed at a position corresponding to an upper side of the formation area of the lead wiring. The touch screen substrate is
On the main surface, further having an electrode provided facing the additional electrode,
The electrode is
The touch panel according to claim 4, wherein the touch panel is disposed excluding a region where the lead wiring is formed. The transparent substrate and the touch screen substrate are bonded via an adhesive,
The additional electrode and the electrode are electrically connected by capacitive coupling via the adhesive,
The touch panel according to claim 5.   The touch panel as set forth in claim 6, wherein the transparent substrate has a larger outer dimension than the touch screen substrate. A first touch screen substrate on which a plurality of first capacitance detection wirings are disposed;
The first touch screen substrate is disposed so as to overlap, and an indicator contacts one of the main surfaces,
A second touch screen substrate having a plurality of second capacitance detection wirings disposed on the other main surface;
Detecting a change in capacitance between the indicator and the plurality of first and second capacitance detection wirings when the indicator is in contact with the second touch screen substrate; A capacitance detection circuit that detects a contact position of the indicator on a second touch screen substrate,
The second touch screen substrate is
An additional electrode in an area other than the sensor effective area of the second touch screen substrate;
The capacitance detection circuit is
Among the plurality of first and second capacitance detection wirings,
A touch panel that provides an AC signal to the additional electrode so that a potential difference between a capacitance detection wiring not used for detecting a change in capacitance due to contact of the indicator and the additional electrode is minimized. The additional electrode is disposed on the other main surface opposite to the one main surface of the second touch screen substrate,
The plurality of first capacitance detection wirings are arranged on a main surface of the first touch screen substrate on a side facing the other main surface of the second touch screen substrate,
The touch panel according to claim 8, wherein the plurality of second capacitance detection wirings are disposed on the other main surface of the second touch screen substrate.   The touch panel according to claim 1, wherein the additional electrode is formed of a light-shielding material. The first touch screen substrate includes:
A first lead wire disposed on the main surface and connecting the plurality of first capacitance detection wires to the outside;
The second touch screen substrate is
A second lead wire disposed on the other main surface and connecting the plurality of second capacitance detection wires to the outside;
The additional electrode is
The touch panel as set forth in claim 9, wherein the touch panel is disposed excluding a region where the second lead wiring is formed. The additional electrode is
The touch panel according to claim 1, wherein the touch panel is covered with an insulating layer except for an electrical connection area with the capacitance detection circuit.   The touch panel as set forth in claim 8, wherein the second touch screen substrate has a larger outer dimension than the first touch screen substrate. A thin film transistor substrate in which a plurality of pixels are arranged in a matrix, and
A color filter substrate having a plurality of capacitance detection wirings stacked on the thin film transistor substrate and disposed on a main surface opposite to the thin film transistor substrate side;
A transparent substrate disposed above the color filter substrate and in contact with an indicator on one main surface opposite to the color filter substrate side;
When the indicator is in contact with the transparent substrate, a change in capacitance between the indicator and the plurality of capacitance detection wirings is detected, and the indicator contacts on the transparent substrate. A capacitance detection circuit for detecting a position;
The transparent substrate is
Having an additional electrode in a region not overlapping the sensor effective region of the color filter substrate;
The capacitance detection circuit is
Among the plurality of capacitance detection wires,
A display device that provides an AC signal to the additional electrode so that a potential difference between a capacitance detection wiring not used for detecting a change in capacitance due to contact of the indicator and the additional electrode is minimized.   A display device comprising the touch panel according to claim 1 on the display surface side of a display device.

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