JP2012022427A - Capacitance-type input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitance-type input device that can suppress erroneous detection and detect an approach of a conductor more precisely.SOLUTION: A capacitance-type input device includes: multiple electrodes y that are formed on a transmission plate 4, arranged in a direction Y, and extend in a second direction crossing the direction Y; an IC chip 8 that detects the approaching position of a finger Fg in the direction Y with a capacitance change between each of the electrodes y and the finger Fg that is approaching the transmission plate 4 from one side of a direction Z that is normal to the transmission plate 4; a flexible circuit board 7 that is formed on an edge of the transmission plate 4 with its front side surface 7a facing one side of the direction Z and with its back side surface 7b facing the other side of the direction Z; and first wires that span the transmission plate 4 and the flexible circuit board 7 to connect the IC chip 8 with the electrodes y. A conductive layer 73 is formed on the front side surface 7a of the flexible circuit board 7, and a wire layer 74 that is structured with part of the first wires is formed on the back side surface 7b of the flexible circuit board 7.

Description

  The present invention relates to a capacitive input device.

  FIG. 14 is a cross-sectional view of an essential part showing an example of a conventional input device. FIG. 15 is a plan view of an essential part of the input device as viewed from above in FIG. The input device 9A shown in these drawings constitutes a so-called touch panel by being superimposed on the liquid crystal display panel 9B. This touch panel is used, for example, as a display unit and an operation unit of the mobile phone 9C. The mobile phone 9C has a transparent cover c1 that constitutes a part of the housing. The input device 9A is joined to the transparent cover c1 by a transparent adhesive c2. A liquid crystal display panel 9B is disposed below the input device 9A in FIG. The description regarding such an input device 9A is, for example, in Patent Document 1.

  The input device 9A includes transparent substrates 91 and 92, a plurality of detection electrodes 93 and 94, a plurality of wirings 95 and 96, flexible substrates 97 and 98, and an IC chip 99. The transparent substrates 91 and 92 are arranged in parallel to each other. The detection electrode 93 is formed on the transparent substrate 91. All the detection electrodes 93 extend along the direction X and are arranged in parallel to each other. The detection electrode 94 is formed on the transparent substrate 92. The detection electrodes 94 extend along the direction Y and are arranged in parallel to each other. The flexible substrates 97 and 98 are provided at the ends of the transparent substrates 91 and 92, respectively. The wiring 95 is formed over the transparent substrate 91 and the flexible substrate 97 and is connected to the detection electrode 93 separately. The wiring 96 is formed across the transparent substrate 92 and the flexible substrate 98 and is connected to the detection electrode 94 separately. The IC chip 99 is individually connected to the detection electrodes 93 and 94 via wirings 95 and 96.

  When the user of the mobile phone 9C operates the mobile phone 9C, the finger Fg (conductor) is brought close to or in contact with the transparent cover c1, so that the finger Fg and the detection electrodes 93 and 94 are statically moved. Electric capacity is generated. The IC chip 99 has a value corresponding to a change in capacitance between the detection electrodes 93 and 94 and the finger Fg (the detection value of capacitance change, hereinafter referred to as “detection value” as appropriate). ”). FIG. 16 is a graph showing the detected value of the capacitance change between the finger Fg and the detection electrode 93 when the finger Fg approaches or comes into contact with the transparent cover c1. By specifying the detection electrode 93 whose detection value has increased, the approach position of the finger Fg in the direction Y can be detected. The same approach as that for detecting the approach position of the finger Fg in the direction Y is performed on the detection electrode 94 to detect the approach position of the finger Fg in the direction X. In this way, the input device 9A detects the approach position of the finger Fg on the XY plane. Note that a region that overlaps the detection electrodes 93 and 94 in the direction Z perpendicular to the transparent substrates 91 and 92 (a region surrounded by a dotted line in FIG. 15) is a detection region r1 that detects the approach of the finger Fg.

  In such an input device 9A, the detection values for the detection electrodes 93 and 94 may change even when the finger Fg is not approaching the transparent cover c1. The main cause of such a change in the detected value is external noise due to other components mounted on the mobile phone 9C.

In addition, the detection value when the same conductor is brought close to or in contact with the detection region r1 of the transparent cover c1 in the same posture may vary for each of the detection electrodes 93 and 94. The main cause of such variation in the detection value is that the parasitic capacitance that can be generated between the wirings 95 and 96 connected to the detection electrodes 93 and 94 and the other wirings and electrodes is different for each of the detection electrodes 93 and 94. There are things.

  Considering the influence of external noise and parasitic capacitance as described above, a predetermined threshold is set for the detection value for each of the detection electrodes 93 and 94, and for example, whether or not the finger Fg has approached the transparent cover c1 is determined. , Depending on whether or not the threshold value is exceeded. For example, the IC chip 99 outputs a signal related to the approach position of the finger Fg to the outside only when the detection values of the detection electrodes 93 and 94 exceed a predetermined threshold value. Here, by setting the threshold value to a value larger than the detection value due to external noise or the like, erroneous detection due to the influence of external noise or the like is prevented. On the other hand, if the threshold value is set to a very large value, it is difficult to detect the approach of the finger Fg itself. Therefore, it is necessary to keep the threshold value small enough to appropriately detect the approach of the finger Fg.

  However, when the finger Fg approaches an area other than the detection area r1, the detection value may change. In particular, in the flexible boards 97 and 98 in which the wirings 95 and 96 and the like tend to be dense, the change in the detected value tends to increase due to the influence of the parasitic capacitance generated between the wirings. There was a risk of unintentional false detection.

JP 2008-33777 A

  The present invention has been conceived under the circumstances described above, and provides a capacitance-type input device capable of suppressing erroneous detection and more accurately detecting the approach of a conductor. Is the subject.

  The capacitive input device provided by the present invention includes a substrate and a plurality of first elements formed on the substrate and extending along a second direction parallel to the first direction and intersecting the first direction. With respect to the detection electrode and a conductor approaching the substrate from one of the third directions perpendicular to the substrate, a change in capacitance generated between the conductor and each first detection electrode causes the change in the first direction. Control means for detecting the approach position of the conductor, a first main surface provided at an end of the substrate and directed to one side in the third direction, and a second directed to the other side in the third direction A flexible substrate having a main surface; and a plurality of first wirings formed across the substrate and the flexible substrate for connecting the control means and each of the plurality of first detection electrodes, The first flexible substrate A conductive layer made of a conductive material is formed on the surface, and a wiring layer including a part of the plurality of first wirings is formed on the second main surface of the flexible substrate. Yes.

  In a preferred embodiment of the present invention, a plurality of second detection electrodes arranged in parallel along the second direction and extending along the first direction, the control means, and each of the plurality of second detection electrodes, And a plurality of second wirings for connecting the two.

  In a preferred embodiment of the present invention, the wiring layer includes a part of the plurality of second wirings.

  In a preferred embodiment of the present invention, the substrate has a planar first surface facing one side of the third direction, and the plurality of first detection electrodes and the plurality of the plurality of first detection electrodes are disposed on the first surface. All of the second detection electrodes are formed.

  In a preferred embodiment of the present invention, each of the first detection electrodes includes a plurality of first electrode elements arranged along the second direction, and each of the second detection electrodes is in the first direction. A plurality of second electrode elements arranged along the first wiring line, wherein the first wiring is electrically connected to any one of the plurality of first electrode elements, and is adjacent to the first and second electrode elements. A plurality of first connection wirings formed on the first surface extending from a gap between the first end and the end of the substrate; and a plurality of first connection wires formed on the second main surface of the flexible substrate. A plurality of second connection wirings corresponding to each of the connection wirings, and cross wirings forming the conductive layer and intersecting the plurality of second connection wirings, the corresponding first and The second connection wiring is such that the second main surface of the flexible substrate is the base. Of which is connected in a state overlapping the first surface, said second contact wirings each other included in the same said first wiring is connected via the cross wiring and through holes in the flexible substrate.

  In a preferred embodiment of the present invention, the first wiring connects two first electrode elements adjacent to each other along the second direction among the plurality of first electrode elements, and these A first connection wiring formed in a gap sandwiched between the two first electrode elements, and any one of the plurality of first connection wirings includes the two first electrode elements or the first first wiring Connect to the connection wiring.

  In a preferred embodiment of the present invention, the second wiring is a second connection wiring that connects two second electrode elements sandwiching the first connection wiring among the plurality of second electrode elements. And the second connection wiring is disposed so as to surround one of the plurality of first electrode elements to which the first connection wiring is connected.

  In a preferred embodiment of the present invention, the conductive layer includes a mesh-shaped shield portion connected to the ground.

  In a preferred embodiment of the present invention, a shield layer made of a conductive material is formed on the second surface on the other side in the third direction of the substrate, and the shield portion is connected to the shield layer. Has been.

  In a preferred embodiment of the present invention, the flexible substrate has a bifurcated structure having a wiring connection portion including a part of the wiring layer and a shield connection portion connected to the shield portion at an end portion on a connection side with the substrate. The second main surface of the wiring connection portion is superimposed on the first surface of the substrate, whereby the first wiring or the second wiring is interposed between the substrate and the flexible substrate. Are connected, and the shield layer and the shield portion are connected to each other by overlapping the first main surface of the shield connection portion on the second surface of the substrate.

  In a preferred embodiment of the present invention, the conductive layer is formed in a region overlapping the wiring layer when viewed in the third direction.

  In a preferred embodiment of the present invention, a transparent cover is further provided opposite to the substrate on one side in the third direction.

  In a preferred embodiment of the present invention, a light transmission layer formed in a gap sandwiched between the first and second electrode elements adjacent to each other, the plurality of first electrode elements, and the plurality of second electrodes An electrode element and a coating layer covering the light transmission layer are further provided.

  In a preferred embodiment of the present invention, the refractive index of the material constituting the light transmission layer is different from the refractive index of the material constituting the coating layer.

  In a preferred embodiment of the present invention, the material constituting the light transmission layer is made of the same material as the material constituting the first electrode element or the second electrode element.

  In a preferred embodiment of the present invention, the light transmission layer includes a plurality of line elements spaced apart from each other.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

It is principal part sectional drawing of the input device concerning 1st Embodiment of this invention. It is a principal part top view which follows the II-II line | wire of FIG. FIG. 3 is a plan view of a principal part showing a partial configuration of the input device shown in FIG. 2. FIG. 3 is a plan view of a principal part showing a partial configuration of the input device shown in FIG. 2. FIG. 3 is an enlarged plan view of a main part showing a partial configuration of the input device shown in FIG. 2. It is principal part sectional drawing which shows the modification of the input device concerning 1st Embodiment of this invention. (A) is a graph which shows the detected value of the electrostatic capacitance change for every electrode y, (b) is a table | surface which shows the numerical value and ratio of the said detected value. It is a principal part top view of the input device concerning 2nd Embodiment of this invention. It is a principal part top view which shows the structure of a part of input device shown in FIG. It is a principal part top view which shows the structure of a part of input device shown in FIG. It is the elements on larger scale of the area | region XI of FIG. It is principal part sectional drawing which follows the XII-XII line | wire of FIG. It is a principal part top view of the input device concerning 3rd Embodiment of this invention. It is principal part sectional drawing of the conventional input device. It is a principal part top view of the input device shown in FIG. It is a histogram which shows the detected value of the electrostatic capacitance change for every detection electrode of the conventional input device.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a main part of the input device according to the present embodiment. FIG. 2 is a plan view of an essential part taken along line II-II in FIG. The input device A10 shown in these drawings includes a plurality of electrodes x, a plurality of electrodes y, a plurality of wirings 31, a plurality of wirings 32, a transmission plate 4, a shield layer 5, a transparent adhesive 61, a transparent cover 62, a flexible A substrate 7 and an IC chip 8 are provided. FIG. 3 is a plan view of a principal part mainly showing the electrode y in FIG. FIG. 4 is a plan view of a principal part mainly showing the electrode x in FIG. FIG. 5 is an enlarged plan view of a main part mainly showing the flexible substrate 7 in FIG.

  The input device A10 is for detecting the approach of a finger Fg, which is a conductor, from one side (upward in FIG. 1) in the direction Z perpendicular to the transmission plate 4 by a change in capacitance. The input device A10 is superposed on the liquid crystal display panel B to constitute a so-called electrostatic capacitance type touch panel.

  2 to 4, a region surrounded by a dotted line is a detection region r1. The detection area r1 is an area for detecting the approach of the finger Fg by causing the finger Fg to approach the input device A10. On the other hand, in these drawings, a frame-shaped region surrounding the detection region r1 in the transmission plate 4 is a non-detection region r2. The boundaries between the detection area r1 and the non-detection area r2 are edge r3, r4 and edge r5, r6. The end edges r3 and r4 are along the direction X, and are located below and above in FIG. The edges r5 and r6 are along the direction Y, and are located on the left and right sides of FIG.

  The transmission plate 4 is transparent and has a flat plate shape. The transmission plate 4 is made of, for example, a single layer resin body of a transparent resin such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or polycarbonate (PC), or two kinds of materials selected from transparent resins represented by these. It is made of a laminated resin body or glass.

  The plurality of electrodes x and the plurality of electrodes y are all formed on the surface 4 a (upper side in FIG. 1) of the transmission plate 4.

  The plurality of electrodes y each extend along the direction X and are arranged in parallel along the direction Y. The plurality of electrodes y are arranged along the direction Y at a pitch of 5 mm, for example. The electrodes y1, y2,... Are sequentially formed from the electrode y arranged on the lower side of FIGS. Any number of electrodes y may be formed, but in the present embodiment, 14 electrodes y are formed. The electrode y is for detecting the approach position of the finger Fg in the direction Y, and corresponds to an example of the first detection electrode in the present invention. The electrode y is obtained by patterning a thin film made of a transparent conductive material such as ITO or IZO.

  As shown in FIGS. 2 and 3, each electrode y includes a plurality of electrode elements 11 arranged along the direction X. The electrode element 11 has a substantially rhombus shape. The shape of the electrode element 11 is not limited to a rhombus shape, and may be a round shape, a polygonal shape, or other shapes.

  The plurality of electrodes x each extend along the direction Y and are arranged in parallel along the direction X. The plurality of electrodes x are arranged along the direction X at a pitch of 5 mm, for example. In order from the electrode y arranged on the left side of FIG. 2 and FIG. Any number of electrodes x may be formed, but in the present embodiment, ten electrodes x are formed. The electrode x is for detecting the approach position of the finger Fg in the direction X, and corresponds to an example of a second detection electrode in the present invention. The electrode x is obtained by patterning a thin film made of a transparent conductive material such as ITO or IZO.

  As shown in FIGS. 2 and 4, each of the electrodes x includes a plurality of electrode elements 21 arranged along the direction Y. The electrode element 21 has a substantially rhombus shape. The shape of the electrode element 21 is not limited to a rhombus shape, and may be a round shape, a polygonal shape, or other shapes. As shown in FIG. 2, a gap s <b> 1 sandwiched between the electrode element 11 and the electrode element 21 is formed on the surface 4 a of the transmission plate 4.

  The shield layer 5 is formed on the back surface 4b (the lower side in FIG. 1) of the transmission plate 4. The shield layer 5 is made of a transparent conductive material such as ITO or IZO. The shield layer 5 is covered with, for example, a rear protective layer (not shown). The shield layer 5 plays a role of blocking external noise.

  The flexible substrate 7 is provided at the end 4c (the lower side in FIG. 2) in the direction Y of the transmission plate 4. The flexible substrate 7 is made of, for example, an insulating material such as polyimide, and has a flat plate shape that is substantially T-shaped in plan view. A conductive layer 73 made of a conductive material is formed on the front surface 7a (upper side in FIG. 1) of the flexible substrate 7, and a wiring layer 74 is formed on the back surface 7b (lower side in FIG. 1) of the flexible substrate 7. Is formed. Details of the conductive layer 73 and the wiring layer 74 will be described later. In FIG. 2, the conductive layer 73 is not shown.

  As shown in FIGS. 1, 2, and 5, the flexible substrate 7 is formed in a bifurcated shape having a wiring connection portion 71 and a shield connection portion 72 at the end portion on the connection side with the transmission plate 4. The wiring connection part 71 is a part for connecting the wirings 31 and the wirings 32 described later. The shield connection part 72 is a part for connecting the shield layer 5 and a shield part 731 described later.

  A plurality of through holes 75 (see FIGS. 1 and 5) are formed at appropriate positions of the flexible substrate 7. Each through-hole 75 is filled with a low-resistance metal material such as Cu for connecting the front surface 7 a side and the back surface 7 b side of the flexible substrate 7.

  As shown in FIG. 2, FIG. 3, or FIG. 5, the plurality of wirings 31 are formed across the transmission plate 4 and the flexible substrate 7. The wiring 31 is connected to the electrode y separately. The wiring 31 includes wirings 311 to 315 formed on the surface 4 a of the transmission plate 4 and wirings 316 to 318 (see FIG. 5) formed on the flexible substrate 7.

  The wiring 311 is connected to the electrode element 11 arranged on the leftmost side or the rightmost side in FIG. Each of the wirings 311 connected to the electrode element 11 arranged on the leftmost side extends from the connected electrode element 11 toward the edge r5, and further extends downward in the figure along the direction Y. On the other hand, all the wirings 311 connected to the electrode element 11 arranged on the rightmost side extend from the connected electrode element 11 toward the edge r6, and further extend downward in the figure along the direction Y. Yes.

  The wiring 312 is connected to the electrode element 11 included in the electrode y14 disposed on the uppermost side in FIG. Each wiring 312 extends from the two electrode elements 11 adjacent in the direction X toward the edge r4 and reaches the non-detection region r2. Thereby, the electrode elements 11 included in the electrode y14 are electrically connected.

  The wiring 313 electrically connects two electrode elements 11 adjacent in the direction X among the electrode elements 11 included in the electrodes y1 to y13. The wiring 313 is formed in a gap sandwiched between these two electrode elements 11. The wiring 313 corresponds to an example of a first connection wiring according to the present invention.

  The wiring 314 is connected to the electrode element 11 included in the electrode y13 arranged second from the top in FIG. Each wiring 314 is connected to one of the two electrode elements 11 connected to the wiring 313 that is arranged on the left side. Each wiring 314 extends from the electrode element 11 toward the edge r4 and reaches the non-detection region r2. The wiring 314 is disposed so as to surround the electrode element 11 included in the electrode y14 and does not have an intersection with the wiring 312. By the wiring 313 and the wiring 314, the electrode elements 11 included in the electrode y13 are electrically connected.

  The wiring 315 is connected to the electrode element 11 included in the electrodes y1 to y12. The wiring 315 is also connected to the two electrode elements 11 connected to the wiring 313 that are arranged on the left side. Each wiring 315 extends downward from the electrode element 11 so as to sew a gap s1 sandwiched between the electrode element 11 and the electrode element 21, and reaches the end 4c of the transmission plate 4 across the edge r3. Yes. The wiring 315 corresponds to an example of the first connection wiring of the present invention. The wirings 311 to 315 described above are made of a transparent conductive material such as ITO or IZO. The width of each wiring 311 to 315 is, for example, 30 to 100 μm.

  The wirings 316 and 317 are formed on the back surface 7 b of the flexible substrate 7. In FIG. 5, the wirings 316 and 317 are represented by dotted lines. The wiring 316 is connected to the wiring 311 separately. The wiring 317 is connected to the wiring 315 separately. Here, the wiring 311 and the wiring 316, and the wiring 315 and the wiring 317 are connected in a state where the back surface 7 b of the flexible substrate 7 overlaps the front surface 4 a of the transmission plate 4. The wiring 317 corresponds to an example of the second connection wiring of the present invention.

  The wiring 318 is formed on the surface 7 a of the flexible substrate 7. The wiring 318 intersects with the wirings 316 and 317 formed on the back surface 7b and the flexible substrate 7 interposed therebetween. In the flexible substrate 7, the wirings 316 and 317 that are electrically connected to the electrode element 11 included in the same electrode y are connected through the wiring 318 and the through hole 75. Thereby, the electrode elements 11 included in the same electrode y (limited to the electrodes y1 to y12) are electrically connected. The wiring 318 corresponds to an example of the cross wiring of the present invention. Further, the wiring 318 constitutes a conductive layer 73. The wirings 316 to 318 described above are made of a low resistance metal material such as Cu. The width of each wiring 316 to 318 is, for example, 30 to 100 μm.

  As shown in FIG. 2, FIG. 4, or FIG. 5, the plurality of wirings 32 are also formed across the transmission plate 4 and the flexible substrate 7 in the same manner as the wirings 31. The wiring 32 is connected to the electrode x separately. The wiring 32 includes wirings 321 to 323 formed on the surface 4 a of the transmission plate 4 and wiring 324 formed on the flexible substrate 7.

  The wiring 321 makes the two electrode elements 21 adjacent in the direction Y conductive. The wiring 321 is formed in a gap sandwiched between these two electrode elements 21. The wiring 322 also connects the two electrode elements 21 adjacent in the direction Y to each other. The wiring 322 is disposed so as to surround one of the two electrode elements 11 connected to the wiring 313 in order to avoid crossing the wiring 313. By being connected to the wiring 321 and the wiring 322, the electrode elements 21 included in the same electrode x are electrically connected. The wiring 322 corresponds to an example of the second connection wiring in the present invention. As shown in FIG. 4, the wiring 323 extends downward from the lowermost electrode element 21 among the electrode elements 21 included in the electrode x, and crosses the edge r <b> 3 to the end of the transmission plate 4. 4c has been reached. The wirings 321 to 323 described above are made of a transparent conductive material such as ITO or IZO. The width of each of the wirings 321 to 323 is, for example, 30 to 100 μm.

  The wiring 324 is formed on the back surface 7 b of the flexible substrate 7. In FIG. 5, the wiring 324 is represented by a dotted line. The wiring 324 is connected to the wiring 323 separately. The wiring 323 and the wiring 324 are connected in a state where the back surface 7 b of the flexible substrate 7 overlaps the front surface 4 a of the transmission plate 4. The wiring 324 is made of a low resistance metal material such as Cu. The width of the wiring 324 is, for example, 30 to 100 μm.

  The wiring layer 74 formed on the back surface 7b of the flexible substrate 7 includes the wirings 316, 317, and 324 described above. The wiring layer 74 is obtained by patterning a thin film made of a low resistance metal material such as Cu.

  The conductive layer 73 formed on the surface 7a of the flexible substrate 7 is obtained by patterning a thin film made of a low-resistance metal material such as Cu, and includes the wiring 318 and the shield portion 731 described above. Consists of. The shield portion 731 has a mesh shape, and is formed, for example, as a pattern having a constant mesh width and a constant repetition pitch. When the input device A10 is incorporated in a predetermined device, the shield portion 731 is connected to the ground. The shield portion 731 is formed so as to cover the wiring layer 74 outside the region where the wiring 318 is formed. Thereby, the conductive layer 73 is formed in a region overlapping the wiring layer 74 in the direction Z.

  The shield portion 731 is also formed up to the end of the shield connection portion 72 that is one of the two forks of the flexible substrate 7. As can be seen from FIGS. 1 and 5, the front surface 7 a of the shield connection portion 72 is superimposed on the back surface 4 b of the transmission plate 4. Thereby, the shield layer 5 formed on the back surface 4 b of the transmission plate 4 and the shield part 731 formed on the front surface 7 a of the flexible substrate 7 are connected. The conductive layer 73 and the wiring layer 74 are covered with a coating layer (not shown) made of an insulating material such as polyimide, for example, except for connection portions such as the wirings 31 and 32.

  The IC chip 8 is mounted on the back surface 7b of the flexible substrate 7, for example. The IC chip 8 is connected to the electrode y via the wiring 31 (wirings 311 to 318). The IC chip 8 is also connected to the electrode x via the wiring 32 (wirings 321 to 324). The IC chip 8 can always and independently measure the detection value for each electrode y. The IC chip 8 can also measure the detection value for each electrode x independently and always.

  The transparent cover 62 is disposed opposite to the transmission plate 4 on one side in the direction Z (upper side in FIG. 1). The transparent cover 62 is joined to the transmission plate 4 via, for example, a transparent adhesive 61. As the transparent adhesive 61, a material that can transmit light well and can insulate the electrode y and the electrode x from each other (for example, an optical pressure-sensitive adhesive) may be used.

  The liquid crystal display panel B includes, for example, a transparent substrate and a TFT substrate facing each other, and a liquid crystal layer sandwiched between them, and has a function of displaying an operation menu screen, an image, and the like for use in operating a mobile phone, for example. . The image displayed on the liquid crystal display panel B is visible through the input device A10. The display surface of the liquid crystal display panel B is disposed so as to overlap the electrodes x and y when viewed in the direction Z.

  The input device A10 and the liquid crystal display panel B are incorporated in a mobile phone or the like and used, for example, as follows.

  On the liquid crystal display panel B, for example, an operation menu screen including icons imitating buttons for exercising various functions of the mobile phone is displayed. When the user does not perform any operation, there is almost no capacitance between the electrodes x and y and the finger Fg. Next, the user brings the finger Fg closer to the surface 62a of the transparent cover 62 from one side in the direction Z by touching an icon corresponding to the function to be selected. Then, the distance between the electrodes x and y and the finger Fg is reduced. Thereby, the electrostatic capacitance between the finger Fg and each electrode x and y changes. Of the plurality of electrodes x and y, the smaller the distance from the finger Fg, the larger the capacitance. The IC chip 8 measures this change in capacitance as a detection value for each of the electrodes x and y. Then, the IC chip 8 detects the approach position of the finger Fg in the direction Y by specifying the electrode y with the increased detection value, and specifies the electrode x with the increased detection value, thereby identifying the finger Fg in the direction X. The approach position of is detected. Through the above procedure, the approach position of the finger Fg in the XY plane can be detected, and the icon that the user is trying to touch can be detected. The mobile phone exhibits a function corresponding to this icon.

  Next, the operation of the input device A10 will be described.

  According to the input device A10, in the flexible substrate 7, on the back surface 7b, the wiring layer 74 configured to include the wirings 316, 317, and 324 is formed, while on the front surface 7a, the conductive layer 73 is formed. . For this reason, when the finger Fg approaches, for example, the flexible substrate 7 other than the detection region r1 from one side in the direction Z, the conductive layer 73 is interposed between the wiring layer 74 and the finger Fg. The conductive layer 73 functions as a shield for the wiring layer 74 (wirings 316, 317, and 324), and suppresses a large change in the detection value for each of the electrodes x and y due to the approach of the finger Fg to the flexible substrate 7. can do. Therefore, according to the above configuration having the wiring layer 74, the approach of the finger Fg in the detection region r1 can be detected more accurately.

  The conductive layer 73 includes a wiring 318 and a mesh-shaped shield portion 731, and the shield portion 731 is formed so as to cover the wiring layer 74 in a region other than the formation region of the wiring 318. Since the shield portion 731 generates a parasitic capacitance with the wiring layer 74, for example, when a film-like shield different from the present embodiment is formed, the parasitic capacitance with the wiring layer 74 increases, which is preferable. Absent. On the other hand, in this embodiment, by making the shield part 731 into a mesh shape having an appropriate mesh density, the parasitic capacitance between the shield part 731 and the wiring layer 74 is reduced while ensuring the shielding performance. Can do. This is suitable for more accurately detecting the approach of the finger Fg in the detection region r1. An example of the mesh density of the shield portion 731 is that the mesh width is about 0.05 to 0.2 mm and the repetition pitch is about 0.8 to 1.5 mm.

  The conductive layer 73 (the wiring 318 and the shield portion 731) is formed in a region overlapping the wiring layer 74 when viewed in the direction Z. For this reason, it can suppress more appropriately that an unjust change appears in a detection value by the approach of the finger | toe Fg with respect to the flexible substrate 7. FIG.

  In the input device A <b> 10, for each wiring 31 for connecting each of the electrodes y <b> 1 to y <b> 12 of the electrode y and the IC chip 8, a plurality of wirings 316 and 317 that are electrically connected to the electrode element 11 are formed on the back surface 7 b of the flexible substrate 7. Is formed. The wirings 316 and 317 included in the same wiring 31 are connected to each other through a wiring 318 formed on the surface 7 a of the flexible substrate 7 and a through hole 75. That is, the intersections of the plurality of wirings 316, 317, and 318 constituting the wiring 31 are concentrated on the flexible substrate 7, and the wirings 316, 317 and the wiring 318 intersect with the flexible substrate 7 therebetween. Yes. Therefore, by ensuring the thickness (interlayer gap) of the flexible substrate 7 appropriately, the parasitic capacitance between the intersections of the wirings 316, 317, and 318 can be reduced. This is suitable for more accurately detecting the approach of the finger Fg in the detection region r1.

  In the input device A <b> 10, two electrode elements 11 adjacent in the direction X are connected by a wiring 313. Therefore, it is possible to make the electrode elements 11 included in the same electrode y (limited to the electrodes y1 to y12) conductive only by connecting the wiring 315 reaching the non-detection region r2 to one of these two electrode elements 11. it can. Thereby, the number of wirings 315 extending from the gap s1 between the electrode element 11 and the electrode element 21 to the non-detection region r2 can be reduced. By reducing the number of wirings 315 reaching the non-detection region r2, the number of intersecting portions of the wirings 316, 317, and 318 in the flexible substrate 7 can be reduced. Thereby, the parasitic capacitance between the wirings 316, 317, and 318 can be reduced. This is suitable for more accurately detecting the approach of the finger Fg in the detection region r1.

  In this embodiment, the shield layer 5 formed on the back surface 4b of the transmission plate 4 is connected to the shield part 731 on the flexible substrate 7, and the shield part 731 is connected to the ground. According to this configuration, the external noise can be appropriately blocked by the shield layer 5.

  The input device A10 shown in FIG. 1 shows an example in which the flexible substrate 7 is incorporated into a device in a state in which the flexible substrate 7 extends straight. However, for example, as shown in FIG. 6, the flexible substrate 7 is bent. May be incorporated into the device. Also in the case illustrated in FIG. 6, it is possible to suppress a large change in the detection value for each of the electrodes x and y due to the approach of the finger Fg to the flexible substrate 7 (for example, the approach of the finger Fg from the upper side or the left side in FIG. 6). be able to.

  FIG. 7 shows a comparative test performed to verify the shielding effect of the shield part 731 in the input device A10.

  As an example, the input device A10 of the present embodiment having the shield portion 731 on the surface 7a of the flexible substrate 7 was prepared, and an input device having no shield portion 731 on the surface 7a of the flexible substrate 7 was prepared as a comparative example. The thickness (interlayer gap) of the flexible substrate 7 was 25 μm, the mesh width of the shield portion 731 was 0.06 mm, and the repetition pitch was 1.41 mm. In these input devices, the detection value of the electrode y when the surface 7a side of the flexible substrate 7 was pressed with a probe as a conductor was measured. FIG. 7A is a graph showing the detection values D1 and D2 for the electrode y with and without the shield part 731. FIG. FIG. 7B shows the numerical values of the detection values D1, D2 and the detection value ratio (D1 / D2) for each electrode y with and without the shield portion 731. FIG.

  As shown in FIG. 7, when the shield portion 731 is provided, the detected value for the electrode y is reduced by about 48% on average compared to the case where the shield portion 731 is not provided, and the conductor is placed on the surface of the flexible substrate 7. It can be seen that the detected value D1 is greatly reduced when approaching 7a. Therefore, erroneous detection can be suppressed when the conductor approaches the flexible substrate 7. For example, when a threshold value is provided at a detection value of 80, a false detection is made if there is no shield part 731, but no false detection is made if there is a shield part 731.

  Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a main part plan view of the input device according to the present embodiment. FIG. 9 is a plan view of a principal part mainly showing the electrode y of FIG. FIG. 10 is a plan view of a principal part mainly showing the electrode x of FIG. FIG. 11 is a partially enlarged view of a region XI in FIG. FIG. 12 is a cross-sectional view of a principal part taken along line XII-XII in FIG. 8 to 12, the same or similar elements as those in the above embodiment are denoted by the same reference numerals as those in the above embodiment, and description thereof will be omitted as appropriate.

  The input device A20 of this embodiment includes a plurality of electrodes x, a plurality of electrodes y, a plurality of wirings 31, 32, a transmission plate 4, and a light transmission layer 53 (see FIGS. 8, 11, and 12, FIGS. 9, 10). ), A coating layer 55 (see FIG. 12, omitted in FIGS. 8 to 11), a flexible substrate 7, and an IC chip (see FIG. 2, not shown in the present embodiment).

  The input device A20 has fewer electrodes x and y than the input device A10. In the input device A20, the number of electrodes x is 8, and the number of electrodes y is 12. In the flexible substrate 7, a conductive layer including a mesh-shaped shield portion is formed on the front surface 7a, and a wiring layer is formed on the back surface 7b (see FIGS. 1 and 5; not shown in the present embodiment). . Since the specific configurations of the electrode x, the electrode y, the wirings 31 and 32, the transmission plate 4, and the flexible substrate 7 are the same as those of the input device A10, description thereof is omitted.

  As clearly shown in FIGS. 11 and 12, the light transmission layer 53 is formed on the surface 4 a of the transmission plate 4. The light transmission layer 53 is formed in a gap s 1 sandwiched between the electrode element 11 and the electrode element 21. The light transmission layer 53 is provided in order to improve visibility. The light incident on the light transmission layer 53 from the transmission plate 4 travels toward the coating layer 55 through the light transmission layer 53. The refractive index of the material constituting the light transmission layer 53 is different from the refractive index of the material constituting the coating layer 55. The refractive index of the material constituting the light transmission layer 53 is preferably approximately the same as the refractive index of the material constituting the electrode elements 11 and 21. In the present embodiment, the light transmission layer 53 is made of the same material as the material (for example, ITO, IZO) constituting the electrode element 11 or the electrode element 21. Therefore, the light transmission layer 53 and the electrode elements 11 and 21 have the same refractive index. In this case, the light transmission layer 53 is formed simultaneously with the formation of the electrode elements 11 and 21 on the surface 4 a of the transmission plate 4. When the light transmissive layer 53 is made of the same material as that of the electrode element 11 and the electrode element 21, it can be said that the light transmissive layer 53 is made of a conductive material. In such a case where the light transmission layer 53 is made of a conductive material, the light transmission layer 53 and the electrode elements 11 and 21 adjacent to the light transmission layer 53 need to be electrically insulated. Therefore, the light transmission layer 53 and the electrode elements 11 and 21 adjacent to the light transmission layer 53 are arranged with a gap therebetween.

  As clearly shown in FIGS. 11 and 12, in the present embodiment, the light transmission layer 53 includes a plurality of line elements 53a and 53b. Each of the line elements 53 a and 53 b has a shape extending in a direction along the edge of the electrode element 11 or the electrode element 21. The plurality of line elements 53a and 53b are arranged in parallel with each other through a gap. The line element 53a is disposed with a gap from the electrode element 11. The line element 53b is disposed with a gap from the electrode element 21.

  As clearly shown in FIGS. 11 and 12, the coating layer 55 covers the electrodes x and y and the light transmission layer 53. The coating layer 55 functions to suppress deterioration of visibility due to reflection of extraneous light or to adhere a transparent cover (not shown). The coating layer 55 is made of a transparent insulating material that transmits light. Examples of such a material include an ultraviolet curable resin. The refractive index of the coating layer 55 is, for example, about 1.5. In addition, the refractive index of the material which comprises the electrodes x and y (electrode elements 11 and 21) is about 2.0, for example. Moreover, the refractive index of the material which comprises the permeation | transmission board 4 is about 1.5, for example.

  Next, the operation of the input device A20 will be described.

  Also in the input device A20, since the conductive layer including the shield portion is formed on the surface 7a of the flexible substrate 7 as in the above-described input device A10, this conductive layer functions as a shield for the wiring layer, and the flexible substrate 7 By approaching the finger Fg, it is possible to suppress a large change from appearing in the detection value for each of the electrodes x and y. Therefore, the approach of the finger Fg in the detection region r1 can be detected more accurately.

  In the input device A20, a part of the light traveling from the transmission plate 4 side toward the coating layer 55 side is reflected at the boundary between the light transmission layer 53 and the coating layer 55. Therefore, the brightness of the region visually recognized by the light that has passed through the gap s1 without passing through the electrode elements 11 and 21 among the images and the like displayed on the liquid crystal display panel B is set as the image or the like displayed on the liquid crystal display panel B. Of these, the brightness of the region visually recognized by the light passing through the electrode elements 11 and 21 can be brought close to. Accordingly, when an image displayed on the liquid crystal display panel B is viewed, a bright region and a dark region are less likely to occur in the image. That is, when an image or the like displayed on the liquid crystal display panel B is viewed, the brightness of the image or the like becomes more uniform. Thus, the input device A20 is suitable for improving the appearance (visibility) of an image or the like displayed on the liquid crystal display panel B.

  In the input device A20, the light transmission layer 53 is made of the same material as that of the electrode elements 11 and 21. As a result, the refractive index of the material constituting the light transmission layer 53 and the refractive index of the material constituting the electrode elements 11 and 21 are the same. Therefore, according to the input device A20, the transmittance of light traveling from the transmission plate 4 side to the coating layer 55 side is determined when light passes through the light transmission layer 53 and when light passes through the electrode elements 11 and 21. , Can be almost identical. Thereby, when an image displayed on the liquid crystal display panel B is viewed, a bright region and a dark region are less likely to occur in the image. That is, when an image or the like displayed on the liquid crystal display panel B is viewed, the brightness of the image or the like becomes more uniform. Thus, the input device A20 is suitable for further improving the appearance (visibility) of an image or the like displayed on the liquid crystal display panel B.

  In the input device A20, the light transmission layer 53 includes a plurality of line elements 53a and 53b disposed with a gap therebetween. Such an input device A40 is suitable for reducing the parasitic capacitance between the electrode elements 11 and 21 adjacent to each other. The following can be considered as one of the reasons.

  The line element 53a is made of a conductive material, and is arranged with a gap from the electrode element 11. Therefore, in the input device A20, it can be said that a capacitor C1 (see FIG. 12) having the electrode element 11 and the line element 53a as an electrode pair is formed. Similarly, the line element 53b is made of a conductive material and is disposed with a gap from the electrode element 21. Therefore, in the input device A20, it can be said that a capacitor C2 (see FIG. 12) having the electrode element 21 and the line element 53b as an electrode pair is formed. In the present embodiment, the line elements 53a and 53b are further arranged with a gap therebetween. Therefore, in input device A20, it can be said that capacitor C3 (refer to Drawing 12) which uses line element 53a and line element 53b as an electrode pair is formed.

  As shown in FIG. 12, the parasitic capacitance between the electrode element 11 and the electrode element 21 adjacent to each other is a combined capacitance of capacitors C1, C2, and C3 connected in series. In this embodiment, it can be said that the capacitor C3 is further connected in series between the capacitors C1 and C2 connected in series. On the other hand, unlike the present embodiment, when the light transmission layer 53 does not include the line elements 53a and 53b arranged with a gap therebetween, that is, when the light transmission layer 53 is a single film-like member, they are adjacent to each other. The parasitic capacitance between the electrode element 11 and the electrode element 21 is a combined capacitance of only the capacitors C1 and C2 connected in series. Therefore, in this embodiment, compared with the case where the light transmission layer 53 does not include the line elements 53a and 53b arranged with a gap between each other, the electrode element 11 and the electrode element 21 are connected to the capacitor element C3 in series. The parasitic capacitance between the two can be reduced. This is suitable for more accurately detecting the approach of the finger Fg in the detection region r1.

  Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 13 is a plan view of an essential part of the input device A30 according to the present embodiment. The input device A30 includes a plurality of electrodes x, a plurality of electrodes y, a plurality of wires 31, 32, a transmission plate 4, a transparent adhesive (see FIG. 1, not shown in the present embodiment), a transparent cover (see FIG. In the embodiment, a flexible substrate 7 and an IC chip 8 are provided.

  The input device A30 has fewer electrodes x and y than the input device A10 of the first embodiment described above. In the input device A30, the number of electrodes x is 5, and the number of electrodes y is 7. In the flexible substrate 7, a conductive layer including a mesh-shaped shield portion is formed on the front surface 7a, and a wiring layer is formed on the back surface 7b (see FIGS. 1 and 5; not shown in the present embodiment). .

  The input device A30 shown in FIG. 13 is different from the above-described input device A10 in that the wiring 31 does not include the wirings 312 to 314 and the wiring 32 does not include the wiring 322. In the input device A30, the wiring 311 is connected to the electrode elements 11 disposed at the left and right ends of each electrode y. For each electrode y, the wiring 315 is connected to the remaining electrode elements 11 excluding the electrode elements 11 at both the left and right ends. Similar to the input device A10, wirings 316 to 318 and 324 are formed on the flexible substrate 7, and the wirings (wirings 316 and 317) that are electrically connected to the electrode element 11 included in the same electrode y are connected to each other. Are connected through a wiring 318 and a through hole 75. In addition, in FIG. 13, each wiring is typically shown and the connection location (through-hole 75) of wiring is shown by the black circle.

  Also in the input device A30, a conductive layer including a shield portion is formed on the surface 7a of the flexible substrate 7 as in the above-described input device A10. Therefore, this conductive layer functions as a shield for the wiring layer, and By approaching the finger Fg, it is possible to suppress a large change from appearing in the detection value for each of the electrodes x and y. Therefore, the approach of the finger Fg in the detection region r1 can be detected more accurately.

  The input device according to the present invention is not limited to the above-described embodiment. The specific configuration of each part of the input device according to the present invention can be modified in various ways.

  Although the case where the input device is used with the liquid crystal display panel B has been described in the above embodiment, the input device according to the present invention is not necessarily used with the liquid crystal display panel. The electrodes x and y are not necessarily transparent. These electrodes may be made of an opaque metal such as Cu.

  The input device according to the present invention is not limited to that used in a mobile phone. For example, it can be used in other devices using a touch panel, such as a digital camera, a personal navigation device, and an automatic deposit payment machine.

A10, A20, A30 Input device B Liquid crystal display panel y, y1 to y14 Electrode (first detection electrode)
x, x1 to x10 electrodes (second detection electrodes)
11 (First) Electrode Element 21 (Second) Electrode Element 22 Wiring Portion 31 Wiring (First Wiring)
311, 312, 314, 316 wiring 313 wiring (first connection wiring)
315 Wiring (first connection wiring)
317 Wiring (second connection wiring)
318 Wiring (cross wiring)
32 wiring (second wiring)
321, 323, 324 wiring 322 wiring (second connection wiring)
4 Transmission plate (substrate)
4a Surface (first surface)
4b Back side (second side)
4c End 5 Shield layer 53 Light transmission layer 53a, 53b Line element 55 Coating layer 61 Transparent adhesive 62 Transparent cover 62a Surface 7 Flexible substrate 7a Surface (first main surface)
7b Back surface (second main surface)
71 Wiring connection portion 72 Shield connection portion 73 Conductive layer 731 Shield portion 74 Wiring layer 75 Through hole 8 IC chip (control means)
s1 Gap r1 Detection area r2 Non-detection areas r3, r4, r5, r6 Edge Y direction (first direction)
X direction (second direction)
Z direction (3rd direction)
Fg finger (conductor)

Claims (16)

A substrate,
A plurality of first detection electrodes formed on the substrate, arranged in parallel along a first direction and extending along a second direction intersecting the first direction;
For a conductor approaching the substrate from one side in a third direction perpendicular to the substrate, a change in capacitance generated between the conductor and each first detection electrode causes the conductor in the first direction to move. Control means for detecting the approach position;
A flexible substrate provided at an end of the substrate and having a first main surface facing one side of the third direction and a second main surface facing the other side of the third direction;
A plurality of first wirings formed across the substrate and the flexible substrate, for connecting the control means and each of the plurality of first detection electrodes;
A conductive layer made of a conductive material is formed on the first main surface of the flexible substrate,
The capacitance-type input device, wherein a wiring layer including a part of the plurality of first wirings is formed on the second main surface of the flexible substrate. A plurality of second detection electrodes arranged in parallel along the second direction and extending along the first direction;
The capacitive input device according to claim 1, further comprising a plurality of second wirings for connecting the control unit and each of the plurality of second detection electrodes.   The capacitive input device according to claim 2, wherein the wiring layer includes a part of the plurality of second wirings.   The substrate has a planar first surface facing one side in the third direction, and both the plurality of first detection electrodes and the plurality of second detection electrodes are formed on the first surface. The capacitive input device according to claim 3. Each of the first detection electrodes includes a plurality of first electrode elements arranged along the second direction,
Each of the second detection electrodes includes a plurality of second electrode elements arranged along the first direction,
The first wiring is electrically connected to one of the plurality of first electrode elements, and extends from a gap sandwiched between the adjacent first and second electrode elements to the end of the substrate. A plurality of first connection lines formed on the first surface; a plurality of second connection lines formed on the second main surface of the flexible substrate and corresponding to each of the plurality of first connection lines; A cross wiring that constitutes the conductive layer and intersects the plurality of second connection wirings,
The corresponding first and second connection wirings are connected in a state where the second main surface of the flexible substrate overlaps the first surface of the substrate,
5. The capacitive input device according to claim 4, wherein the second connection wirings included in the same first wiring are connected to each other through the cross wiring and the through hole in the flexible substrate. 6. The first wiring connects two first electrode elements adjacent to each other along the second direction among the plurality of first electrode elements, and is sandwiched between the two first electrode elements. Provided with a first connection wiring formed in the gap,
6. The capacitive input device according to claim 5, wherein any one of the plurality of first connection wirings is connected to the two first electrode elements or the first connection wiring. The second wiring includes a second connection wiring that connects two second electrode elements sandwiching the first connection wiring among the plurality of second electrode elements,
The capacitive input according to claim 6, wherein the second connection wiring is disposed so as to surround one at one end of the plurality of first electrode elements to which the first connection wiring is connected. apparatus.   The capacitance type input device according to claim 1, wherein the conductive layer includes a mesh-shaped shield portion connected to a ground. A shield layer made of a conductive material is formed on the second surface on the other side in the third direction of the substrate,
The capacitive input device according to claim 8, wherein the shield part is connected to the shield layer. The flexible board has a bifurcated shape having a wiring connection part including a part of the wiring layer and a shield connection part connected to the shield part at a connection side end part with the board,
The first wiring or the second wiring is connected between the substrate and the flexible substrate by overlapping the second main surface of the wiring connection portion on the first surface of the substrate,
The capacitive input according to claim 9, wherein the shield layer and the shield portion are connected by overlapping the first main surface of the shield connection portion on the second surface of the substrate. apparatus.   The capacitive input device according to claim 1, wherein the conductive layer is formed in a region overlapping with the wiring layer when viewed in the third direction.   The capacitive input device according to claim 1, further comprising a transparent cover disposed to face the substrate on one side in the third direction. A light-transmitting layer formed in a gap sandwiched between the first and second electrode elements adjacent to each other;
The capacitive input device according to claim 5, further comprising: the plurality of first electrode elements, the plurality of second electrode elements, and a coating layer covering the light transmission layer.   The capacitive input device according to claim 13, wherein a refractive index of a material constituting the light transmission layer is different from a refractive index of a material constituting the coating layer.   The capacitive input device according to claim 13 or 14, wherein the material constituting the light transmission layer is made of the same material as that constituting the first electrode element or the second electrode element.   The capacitive input device according to claim 15, wherein the light transmission layer includes a plurality of line elements spaced apart from each other.

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