JP5489919B2 - Sensor plate and method of manufacturing sensor plate - Google Patents

Description

  The present invention relates to a sensor plate and a method for manufacturing the sensor plate.

  2. Description of the Related Art Conventionally, an input device that detects an input operation on an electronic device or the like using a change in capacitance is known. As an input device that detects a change in capacitance, for example, an input device that includes a sensor plate for detecting the position of an input body that performs an input operation is known. As an example of such a sensor plate, Patent Document 1 discloses an insert sheet in which a base sheet on which an electrode serving as a sensor for detecting a change in capacitance is formed is integrated with a molding resin by insert molding. It is disclosed.

JP 2009-238661 A

In the input device described in Patent Document 1, since the wiring for connecting the insert sheet to the detection circuit that detects a change in capacitance is drawn out from a part of the base sheet in a band shape, the wiring drawn out in the band shape It is difficult to reduce the size of the input device.
The inventors of the present invention considered providing a through hole in the molding resin instead of drawing the wiring in a strip shape and drawing the wiring through the through hole. However, the inventors have found the following problems in producing a sensor plate in which a through hole for drawing out a wiring is provided in a molding resin. That is, if a through hole is provided in the molding resin and the insert sheet is exposed in the through hole, the surface of the base sheet may be deformed by the sink of the molding resin, which may impair the appearance of the sensor plate. .

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a sensor plate that is small in size and excellent in aesthetics, and a method for manufacturing the sensor plate.

In order to solve the above problems, the present invention proposes the following means.
The sensor plate of the present invention is a sensor plate used in an input device that detects a position where the input body comes into contact with the input body when the input body comes into contact with the substrate, which is formed into a thin plate or a film, and the substrate is thick. The input part formed on one side of the both sides in the thickness direction of the substrate formed so as to be raised or depressed in the vertical direction, and overlapped with the input unit when viewed from the thickness direction of the substrate, A detection electrode disposed on the other surface in the thickness direction of the substrate; a relay electrode provided on the other surface and electrically connected to the detection electrode; the detection electrode and the relay electrode A rigid member made of a resin that is fixed to the entire other surface of the substrate and seals the detection electrode and the relay electrode and reinforces the substrate, and sandwiches the rigid member Relay power Characterized in that it comprises a transmitting and receiving electrode for transmitting and receiving inductive radio signal to the relay electrode has oppositely disposed electrode surface and.

  Further, it is preferable that the rigid member at a position overlapping the relay electrode when viewed from the thickness direction of the substrate is thinner than the rigid member at another position.

  Moreover, it is preferable that the rigid member is formed with a support portion for supporting the transmission / reception electrode.

  The sensor plate manufacturing method of the present invention is a sensor plate manufacturing method used in an input device that detects a position where the input body is in contact with the input body when the input body is in contact with the substrate. A sensor sheet forming step of forming a sensor sheet by stacking a detection electrode and a relay electrode electrically connected to the detection electrode on one surface in the vertical direction; and at least the sensor sheet is plastically deformed A three-dimensional forming step of forming the sensor sheet so that the substrate is raised or depressed in the thickness direction at a position where the detection electrode is disposed; and after the three-dimensional forming step, an entire surface of one surface of the sensor sheet A liquid resin is injected into the substrate, and the detection electrode and the relay electrode are sealed between the sensor sheet and the resin, and conform to the shape of the substrate. The resin is cured to form a rigid member, characterized in that it comprises a sealing step of integrally molded with said substrate and said rigid member.

  In addition, after the sealing step, in the cured resin, the surface opposite to the surface in contact with the sensor sheet is overlapped with the relay electrode when viewed from the thickness direction of the sensor sheet with respect to the relay electrode. It is preferable to further include a transmitting / receiving electrode mounting step for mounting a transmitting / receiving electrode for transmitting / receiving the induction radio signal.

  In the sealing step, it is preferable that the thickness of the rigid member at a position overlapping the relay electrode as viewed from the thickness direction of the sensor sheet is smaller than the thickness of the rigid member at other positions.

  According to the sensor plate and the manufacturing method thereof of the present invention, the rigid member is provided on the entire surface of one side of the substrate, and the relay electrode can transmit and receive signals to and from an external circuit via the rigid member. Therefore, it is possible to provide a sensor plate that is small and excellent in aesthetics.

It is a top view of an input device provided with a sensor plate of one embodiment of the present invention. It is sectional drawing in the AA of FIG. It is sectional drawing in the BB line of FIG. It is a bottom view of the sensor sheet in the sensor plate. It is a bottom view of the sensor plate. It is a perspective view which shows the transmission / reception electrode in the sensor plate. It is an expanded sectional view which expands and shows a part of FIG. It is a flowchart which shows the manufacturing method of the sensor plate of one Embodiment of this invention.

A sensor plate 10 and a method for manufacturing the sensor plate 10 according to an embodiment of the present invention will be described using the input device 1 including the sensor plate 10 as an example.
FIG. 1 is a plan view of an input device 1 including a sensor plate 10 according to an embodiment of the present invention. 2 is a cross-sectional view taken along line AA in FIG. 3 is a cross-sectional view taken along line BB in FIG. FIG. 4 is a bottom view of the sensor sheet 11 in the sensor plate 10. FIG. 5 is a bottom view of the sensor plate 10.
The input device 1 is for an operator of an electronic device or the like to input an operation to the electronic device or the like. As shown in FIGS. 1 and 2, the input device 1 includes a substantially plate-shaped sensor plate 10 that can contact an input body 100 made of a conductor, and a circuit board 21 connected to the sensor plate 10. Examples of the input body 100 that can be used with the input device 1 include an operator's finger and a stylus pen. Although details will be described later, the input device 1 of the present embodiment is configured so that an input operation can be suitably performed with an operator's finger.

  As shown in FIG. 3, the sensor plate 10 includes a sensor sheet 11 formed into a thin plate or a film, a rigid member 17 integrally formed with the sensor sheet 11 in the thickness direction of the sensor sheet 11, and a sensor sheet. 11 and a transmission / reception electrode 19 for electrically connecting the circuit board 21 to the circuit board 21. In the following description, the sensor sheet 11 side is on the upper side and the rigid member 17 side is on the lower side.

As shown in FIGS. 1 to 4, the sensor sheet 11 includes a substrate 12, an input unit 13 provided on the upper surface of the substrate 12, and a detection electrode 15 and a relay electrode 16 provided on the lower surface of the substrate 12. . Although not shown, a decoration layer in which letters or designs are formed by a coating film, resin, or the like can be appropriately provided on the upper surface of the sensor sheet 11.
The substrate 12 is made of a thermoplastic resin formed into a thin plate or film. As a material constituting the substrate 12, a material having a high dielectric constant is preferable. For example, polyester resin, polypropylene resin, vinyl chloride resin, polyethylene resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polycarbonate resin, nylon resin, vinylon resin, acetate resin, polyethylene resin, polyamide resin, polyacrylic resin Polyvinyl chloride resin, polyvinyl alcohol, polyethylene naphthalate, polyacryl, polyvinylidene fluoride, polyarylate, styrene elastomer, polyester elastomer and other thin plates, sheets, or films can be used as the material of the substrate 12. .

  As shown in FIG. 1, the input unit 13 is disposed to face the first input unit 13 </ b> A provided substantially in the center when the substrate 12 is viewed from the thickness direction, with the first input unit 13 </ b> A interposed therebetween. A second input unit 13B and a third input unit 13C are provided.

As shown in FIGS. 1 and 2, the first input portion 13 </ b> A is formed in a hollow shape that is depressed downward from the upper surface of the substrate 12, and has a contour shape when viewed from the thickness direction of the sensor sheet 11. It is formed in a circle. The first input section 13A is divided into four sector-shaped input areas 14 having a central angle of 90 °.
The second input portion 13B is formed so as to protrude upward from the substrate 12. The contour shape of the second input portion 13B when viewed from the thickness direction of the sensor sheet 11 is an oval shape whose major axis is curved along the outer periphery of the first input portion 13A.
The third input portion 13 </ b> C is formed to be depressed below the substrate 12. The contour shape of the second input portion 13B when viewed from the thickness direction of the sensor sheet 11 is symmetrical to the second input portion 13B across the first input portion 13A, and is formed on the outer periphery of the first input portion 13A. It has an oval shape with a major axis curved along the axis.

  The raised or depressed shape in each input portion 13 is formed by transferring a predetermined mold shape to the sensor sheet 11 by vacuum formation or pressure formation.

  Each input unit 13 is formed in a different shape so that each input unit 13 can be identified by tactile sensation when an input operation is performed with an operator's finger. Therefore, the operator can determine the position of the input unit 13 and the direction in which the finger should be moved in each input unit 13 through a tactile sense. Accordingly, even when the operator uses the input device 1 with a finger, for example, in a dark place, or when the operator cannot directly see the input device 1, the operator preferably applies to each input unit 13. Input operation can be performed.

As shown in FIGS. 2 and 4, the detection electrode 15 is for detecting a change in capacitance between the input body 100 and each input unit 13 as viewed from the thickness direction of the substrate 12. A pattern is formed on the lower surface of the substrate 12 so as to overlap.
On the back side of the first input portion 13A, four first detection electrodes 15A (first detection electrodes 15A-1 to 15A-1 to 15th) arranged in the inner region of each input region 14 when viewed from the thickness direction of the sensor plate 10. One detection electrode 15A-4) is formed.
On the back side of the second input portion 13B, a plurality of second detection electrodes 15B (in the present embodiment, the second detection electrodes 15B-1 to 15B-1 to the second detection electrode 15B) are arranged apart from each other along the long axis direction of the second input portion 13B. A total of seven detection electrodes 15B-7 are formed.
On the back side of the third input portion 13C, a plurality of third detection electrodes 15C (in the present embodiment, the third detection electrodes 15C-1 to 15C-1 to the third detection electrode 15B) are arranged apart from each other along the long axis direction of the second input portion 13B. A total of seven detection electrodes 15C-7 are formed.
As the material of each detection electrode 15, a metal foil or paste such as copper, silver, or gold, or a conductive paint can be employed.

  As shown in FIG. 4, the relay electrode 16 is electrically connected to the detection electrode 15 by a wiring pattern, and is provided in the same number as each detection electrode 15. Three relay electrodes 16 are provided side by side at a position away from the detection electrode 15 on the lower surface of the substrate 12. Each relay electrode 16 is formed in a thin film shape having a quadrangular outline when viewed from the thickness direction of the substrate 12. The relay electrode 16 and the wiring are integrally formed with the detection electrode 15 using the same material as the detection electrode 15.

  As a method for forming the detection electrode 15, the relay electrode 16, and the wiring connecting the detection electrode 15 and the relay electrode 16, a printing method such as a gravure printing method, a screen printing method, an offset printing method, or the like is appropriately selected and used. it can.

  As shown in FIGS. 2 and 3, the rigid member 17 is a substantially plate-like member integrally provided on the lower surface of the sensor sheet 11 by an insert molding method described later. The rigid member 17 has higher rigidity than the sensor sheet 11 and can maintain the three-dimensional shape of the sensor sheet 11. The rigid member 17 is formed thicker than the sensor sheet 11 except for a position overlapping the relay electrode 16 when viewed from the thickness direction of the sensor plate 10.

As shown in FIGS. 3 and 5, the rigid member 17 at a position overlapping the relay electrode 16 when viewed from the thickness direction of the sensor plate 10 is a guided radio signal between the relay electrode 16 and a transmission / reception electrode 19 described later. It is formed to a thickness that can transmit and receive. Note that the thickness of the rigid member 17 at a position overlapping the relay electrode 16 when viewed from the thickness direction of the sensor plate 10 may be thinner or thicker than the thickness of the sensor sheet 11. May be the same.
Further, the rigid member 17 is formed with a cylindrical support portion 18 that surrounds the relay electrodes 16 that are arranged in three when viewed from the thickness direction of the sensor plate 10. The support portion 18 is formed with a substantially rectangular parallelepiped space into which the transmission / reception electrode 19 can be inserted. Thereby, the support part 18 can support the transmission / reception electrode 19 inserted in the inside of the support part 18.

  The rigid member 17 is made of a thermoplastic resin. For example, a polyolefin resin such as polyethylene or polypropylene, a polystyrene resin, a polyvinyl chloride resin, a poly (meth) acrylate resin, an acrylic resin, a polyacetal resin, polyethylene terephthalate, or polybutylene. A polyester resin such as terephthalate, a polyamide resin, a polycarbonate resin, a polyphenylene sulfide resin, a polyimide resin, an ABS resin, or the like can be used alone or in combination of two or more.

FIG. 6 is a perspective view showing the transmission / reception electrode 19 in the sensor plate 10. FIG. 7 is an enlarged cross-sectional view showing an enlarged portion indicated by a symbol X in FIG.
As shown in FIG. 6, the transmitting / receiving electrode 19 is formed by integrally forming three rectangular parallelepiped conductive rubbers 19a with an insulator 19b interposed therebetween.
As shown in FIG. 3 and FIG. 7, one side of each conductive rubber 19 a of the transmission / reception electrodes 19 is arranged to face each relay electrode 16 arranged side by side. Further, the surface opposite to the one surface of the conductive rubber 19 a disposed to face each relay electrode 16 is in contact with a later-described land 22 on the circuit board 21.
Thereby, in the transmission / reception electrode 19, the surface facing each relay electrode 16 becomes the first electrode surface 20a for transmitting and receiving the induction radio signal to the relay electrode 16, and the surface opposite to the first electrode surface 20a is the circuit. The second electrode surface 20b for inputting / outputting a drive signal to be described later to the substrate 21 is configured.

As shown in FIGS. 2 and 7, the circuit board 21 includes a plurality of lands 22 for connection to the respective transmission / reception electrodes 19, and a detection circuit chip 23 connected to each of the lands 22.
The detection circuit chip 23 transmits and receives a high-frequency drive signal to and from each detection electrode 15 (see FIG. 4), thereby changing the capacitance between the input body 100 (see FIG. 2) and each detection electrode 15. A detection circuit for detecting is provided. The detection circuit chip 23 generates a high-frequency drive signal, and transmits this drive signal to the detection electrode 15 through the land 22, the transmission / reception electrode 19, the relay electrode 16, and the wiring. Further, the detection circuit chip 23 is configured such that the drive signal transmitted to the detection electrode 15 is input as a detection signal, and the electrostatic capacitance in the detection electrode 15 is based on the generated drive signal and the input detection signal. A change in capacity is detected.

Next, a method for manufacturing the sensor plate 10 will be described.
FIG. 8 is a flowchart showing a method for manufacturing the sensor plate 10.
The sensor plate 10 is manufactured using an insert molding method.
First, the detection electrode 15, the wiring, and the relay electrode 16 are patterned on the lower surface of the substrate 12 to form the sensor sheet 11 (sensor sheet forming step S1 shown in FIG. 8).
Next, the sensor sheet 11 is heated to soften the substrate 12, and the sensor sheet 11 is plastically deformed by forming a vacuum or compressed air, and the raised or depressed input unit 13 is formed at the position where the detection electrode 15 is disposed. (3D forming step S2 shown in FIG. 8).
Next, the rigid member 17 is integrally formed on the lower surface of the sensor sheet 11 using a molding die having an upper mold along the three-dimensional shape on the upper surface of the sensor sheet 11 and a lower mold along the three-dimensional shape on the lower surface of the rigid member 17. (Seal process S3 shown in FIG. 8).

  In the sealing step S3, first, the sensor sheet 11 is attached to the upper mold, the upper mold and the lower mold are combined to close the mold, and a space is formed between the sensor sheet 11 and the lower mold. At this time, there is a space between the entire lower surface of the sensor sheet 11 and the lower mold. Next, a liquid molding resin is injected between the sensor sheet 11 and the lower mold, and the injected molding resin is cooled and solidified. Then, the molding resin comes into close contact with the entire lower surface of the sensor sheet 11 and becomes the rigid member 17 to which the mold shape of the lower mold is transferred. At this time, the rigid member 17 covers the entire lower surface of the sensor sheet 11 including the relay electrode 16.

When liquid molding resin is poured into a mold by insert molding and cooled and solidified, the volume of the molding resin shrinks due to cooling. On the other hand, the volume of the sensor sheet 11 does not change because the sensor sheet 11 is disposed in the mold in a solid state from the beginning. For this reason, the compressive force in the surface direction of the sensor sheet 11 is applied to the sensor sheet 11 by the shrinkage force of the molding resin. Therefore, if there is a portion where the molding resin is not injected on the lower surface of the sensor sheet 11, the portion is likely to be distorted.
In the present embodiment, since the molding resin is injected over the entire lower surface of the sensor sheet 11, the compressive force applied to the sensor sheet 11 after insert molding is dispersed, and the amount of distortion can be reduced. Thereby, it can be set as the sensor plate 10 excellent in aesthetics.
This ends the sealing step S3.

When the sealing step S <b> 3 is completed, the integrally molded product of the sensor sheet 11 and the rigid member 17 is taken out from the mold, and the transmission / reception electrode 19 is inserted into the support portion 18. As a result, the transmission / reception electrode 19 is arranged to face the relay electrode 16 at a position overlapping the relay electrode 16 when viewed from the thickness direction of the substrate 12 (transmission / reception electrode mounting step S4 shown in FIG. 8).
Thereafter, the circuit board 21 is attached to the sensor plate 10 so that the second electrode surface 19b of the transmission / reception electrode 19 and the land 22 of the circuit board 21 are in contact with each other, and the manufacturing process of the input device 1 is completed.

Next, the operation when the input device 1 is used will be described focusing on the action of the sensor plate 10.
In the input device 1, as shown in FIG. 3, the sensor plate 10 and the circuit board 21 are electrically connected via the transmission / reception electrode 19. At this time, a section between the detection circuit chip 23 on the circuit board 21 and the transmission / reception electrode 19 and a section from the relay electrode 16 to the detection electrode 15 is a wired section, and a signal is transmitted between the transmission / reception electrode 19 and the relay electrode 16 by an induced radio signal. The wireless zone Z (see FIG. 7) is transmitted and received.
The detection circuit chip 23 repeatedly outputs a drive signal to each detection electrode 15. Further, the detection circuit chip 23 repeatedly detects the capacitance at each detection electrode 15.

  As shown in FIG. 2, when the operator of the input device 1 brings the input body 100 into contact with the input unit 13, the input body 100 comes close to the detection electrode 15, thereby causing a gap between the detection electrode 15 and the input body 100. A capacitor is formed with the substrate 12 sandwiched therebetween. The electrostatic capacitance between the detection electrode 15 and the input body 100 increases as the distance of the input body 100 to the detection electrode 15 decreases. This change in capacitance is input to the detection circuit chip 23 as a change in detection signal via the wireless section Z (see FIG. 7) between the transmission / reception electrode 19 and the relay electrode 16. Thereby, the detection circuit chip 23 discriminates the detection electrode 15 in which the input body 100 is close, and outputs data indicating to which detection electrode 15 the input body 100 is close.

Data output from the detection circuit chip 23 of the input device 1 is input to an electronic device connected to the input device 1, for example. The electronic device determines what operation input has been made to the input unit 13 of the sensor plate 10 based on the data output from the detection circuit chip 23, and performs a predetermined operation based on the determination result.
Thus, even in the wireless zone Z in which the relay electrode 16 and the transmission / reception electrode 19 are not in contact with each other, the input device 1 according to this embodiment can detect an input operation by the input body 100.

  As described above, according to the sensor plate 10 and the method of manufacturing the sensor plate 10 of the present embodiment, the rigid member 17 is provided on the entire surface of one surface of the substrate 12, and the relay electrode 16 is the rigid member 17. Therefore, the sensor sheet 11 can be prevented from being deformed by sink marks of the rigid member 17, and the sensor plate 10 is small and excellent in aesthetics. be able to.

  As mentioned above, although embodiment and Example of this invention were explained in full detail with reference to drawings, the concrete structure is not restricted to this Embodiment and Example, The design change of the range which does not deviate from the summary of this invention Etc. are also included.

  For example, a transparent electrode film can be adopted as a material for the detection electrode 15, the wiring, and the relay electrode 16. As a material for the transparent electrode film, for example, a light-transmitting conductive polymer SEPLEGYDA (registered trademark) made of Shin-Etsu Polymer or a transparent conductive film made of ITO (Indium Tin Oxide) may be employed. it can. For example, when the substrate 12 and the decorative layer are made of a light-transmitting material, the detection electrode 15, the wiring, and the relay electrode 16 can be made difficult to see.

  In addition, the material of the detection electrode 15, the wiring, and the relay electrode 16 may be other than a metal material. For example, a carbon electrode or the like may be employed as the detection electrode 15, the wiring, and the relay electrode 16.

  In the above-described embodiment, as an example of the shape of the relay electrode 16, an example in which the contour shape when viewed from the thickness direction is a quadrangle is illustrated, but the shape of the relay electrode 16 is not limited thereto. . For example, the relay electrode 16 may have a polygonal shape, a circular shape, an annular shape, or the like. In addition, in order to increase the facing area between the relay electrode 16 and the transmission / reception electrode 19, the shape of each of the relay electrode 16 and the transmission / reception electrode 19 can be an appropriate shape.

  Moreover, although the example in which the support portion 18 is formed in a cylindrical shape is shown in the above-described embodiment, the shape of the support portion 18 is not limited to the cylindrical shape. For example, the support portion 18 may be configured to support the transmission / reception electrode 19 by surrounding the transmission / reception electrode 19 with a plurality of protrusions, or may have a pair of plate shapes sandwiching the side surface of the transmission / reception electrode 19.

DESCRIPTION OF SYMBOLS 1 Input device 10 Sensor plate 11 Sensor sheet 12 Substrate 13 Input part 13A First input part 13B Second input part 13C Third input part 14 Input region 15 Detection electrode 15A First detection electrode 15B Second detection electrode 15C Third detection electrode 16 Relay electrode 17 Rigid member 18 Support part 19 Transmission / reception electrode 20a First electrode surface 20b Second electrode surface 21 Circuit board 22 Land 23 Detection circuit chip S1 Sensor sheet formation step S2 Three-dimensional molding step S3 Sealing step S4 Transmission / reception electrode attachment step 100 input body

Claims (6)

A sensor plate used in an input device that detects a position where the input body is in contact with the input body,
A substrate formed into a thin plate or film; and
An input unit formed on one side of both sides of the substrate in the thickness direction, wherein the substrate is formed to be raised or depressed in the thickness direction;
A detection electrode disposed on the other surface of both sides of the substrate in the thickness direction so as to overlap the input unit as viewed from the thickness direction of the substrate;
A relay electrode provided on the other surface and electrically connected to the detection electrode;
A rigid member made of a resin that is fixed to the entire surface of the other surface of the substrate, sandwiching the detection electrode and the relay electrode, and that seals the detection electrode and the relay electrode and reinforces the substrate; ,
A transmission / reception electrode having an electrode surface disposed opposite to the relay electrode with the rigid member interposed therebetween, and transmitting / receiving an induction radio signal to / from the relay electrode;
A sensor plate comprising:   2. The sensor plate according to claim 1, wherein the rigid member at a position overlapping the relay electrode when viewed from the thickness direction of the substrate is thinner than the rigid member at another position.   The sensor plate according to claim 1, wherein the rigid member is provided with a support portion that supports the transmission / reception electrode. A method of manufacturing a sensor plate used in an input device that detects a position where the input body is in contact with the input body,
A sensor sheet forming step of forming a sensor sheet by laminating a detection electrode and a relay electrode electrically connected to the detection electrode on one surface in the thickness direction of the substrate formed in a sheet shape;
A three-dimensional forming step of forming the sensor sheet so that the substrate is raised or depressed in the thickness direction at least at the position where the detection electrode is disposed by plastically deforming the sensor sheet;
After the three-dimensional molding step, a liquid resin is injected over the entire surface of one side of the sensor sheet, the detection electrode and the relay electrode are sealed between the sensor sheet and the resin, and the substrate A sealing step in which the resin is cured to a shape along the shape to form a rigid member, and the rigid member and the substrate are integrally formed;
A method for manufacturing a sensor plate, comprising:   After the sealing step, the cured resin is guided to the relay electrode at a position overlapping the relay electrode when viewed from the thickness direction of the sensor sheet on the surface opposite to the surface in contact with the sensor sheet. The method of manufacturing a sensor plate according to claim 4, further comprising a transmission / reception electrode attachment step of attaching a transmission / reception electrode for transmitting / receiving a radio signal.   In the sealing step, the thickness of the rigid member at a position overlapping the relay electrode when viewed from the thickness direction of the sensor sheet is made thinner than the thickness of the rigid member at another position. Item 6. The method for producing a sensor plate according to Item 4 or 5.

Images