JP2012238129A - Capacitance type input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitance type input device capable of inexpensively preventing hindrance to detection caused by intervenient air between a control panel and a capacitive sensor sheet, by bringing them closer to each other.SOLUTION: A capacitance type input device includes: an optically transparent front panel 11 approached by the finger of a user; a capacitive sensor sheet 12 for detecting a change in capacitance between a finger having approached the front panel 11 and a X detection electrode or a Y detection electrode; and a light guide 22 installed at a rear face side, which is the other side of an opposed face opposing to the front panel 11 of the capacitive sensor sheet 12. At least rear face peripheral part of the capacitive sensor sheet 12 and the light guide 22 are adhered with compressible elastic bonding agent 25 to be modularized. The capacitive sensor sheet 12 is closely in contact with the front panel 11 with the compressible elastic bonding agent 25, resulting in no fear that air flows into a gap between the front panel 11 and capacitive sensor sheet 12 to cause deterioration in detection sensitivity.

Description

  The present invention relates to a capacitance-type input device used for home appliances, information communication devices, and the like.

  A recent information communication device 1 is configured as shown in FIG. 6, for example, and includes a capacitance-type input device 10 that is simple and easy to handle and can be reduced in thickness for operation. As shown in FIG. 7, this type of capacitive input device 10 includes a front panel 11 approaching a user's finger, which is a conductor, and a finger approaching the front panel 11 and a detection electrode of a pattern layer. A capacitance sensor sheet 12 for detecting a change in capacitance between the light sensor 22 and a light guide 22 installed on the back surface side of the capacitance sensor sheet 12 opposite to the front surface facing the front panel 11. It is prepared for.

  The front panel 11 and the capacitance sensor sheet 12 are each provided with light transparency, and the capacitance sensor sheet 12 is adhered to the back surface of the front panel 11 via a flexible transparent adhesive sheet 30. The capacitance sensor sheet 12 is formed by laminating a conductive pattern layer on a light-transmitting base material layer having insulation, for example, and this pattern layer is formed by a plurality of detection electrodes having light transmittance. A routing line connected to the plurality of detection electrodes is connected to the control device (see Patent Documents 1, 2, and 3).

  When the capacitance sensor sheet 12 is separated from the front panel 11, the finger detection sensitivity decreases. Therefore, it is preferable that the capacitance sensor sheet 12 be as close as possible to the back surface side of the front panel 11 from the viewpoint of ensuring finger detection sensitivity. The light guide 22 guides the light beam incident from the light source 23 to the inside and irradiates it in the direction of the capacitance sensor sheet 12 to illuminate the front panel 11 and the capacitance sensor sheet 12.

JP 2009-187854 A JP 2009-259692 A JP 2008-310556 A

  The conventional capacitance type input device 10 is configured as described above, and the capacitance sensor sheet 12 needs to be in close contact with the back surface side of the front panel 11 without a gap. However, the close contact without any gap is not easy because of the handling property of the thin and flexible adhesive sheet 30 and the positional relationship with the peripheral components of the information communication device 1, and so on. Therefore, the front panel 11, the capacitance sensor sheet 12, and the adhesive There are cases in which gaps are irregularly formed between the sheets 30 and air flows into the gaps, leading to a decrease in detection sensitivity or an unsightly air pocket.

  In particular, when the adhesive sheet 30 is used, once the adhesive sheet 30 is adhered, it is easy to remove air flowing between the front panel 11 and the adhesive sheet 30 or between the capacitance sensor sheet 12 and the adhesive sheet 30. Not a thing. As a method for preventing the inflow of air, a method is conceivable in which a vacuum environment is formed by a vacuum pump or the like, and the capacitance sensor sheet 12 is adhered to the front panel 11 with the adhesive sheet 30 in this vacuum environment. However, when this method is employed, a new problem arises in that large-scale facilities are required and the cost increases. Further, when the capacitance sensor sheet 12 and the light guide 22 are in contact with each other, unnecessary light scattering (light leakage) may be caused at the contact point.

  The present invention has been made in view of the above. By bringing the operation panel and the capacitance sensor sheet close to each other, it is possible to suppress at low cost that air is interposed between the operation panel and the detection trouble. An object of the present invention is to provide a capacitive input device.

In the present invention, in order to solve the above-described problem, a static electricity detecting device detects a change in capacitance between a light-transmitting operation panel approaching a conductor and a conductor approaching the operation panel and the detection electrode of the pattern layer. A capacitance sensor sheet, and a backup material provided on the non-facing surface opposite to the facing surface facing the operation panel of the capacitance sensor sheet,
At least the non-facing surface periphery of the capacitance sensor sheet and the backup material are bonded with a compressible and deformable elastic adhesive to make a module, and the capacitance sensor sheet is brought closer to the operation panel with the elastic adhesive. It is characterized by.

The capacitance sensor sheet includes an insulating base material layer facing the back surface of the operation panel and a pattern layer in which at least a plurality of detection electrodes are arranged on the base material layer. Flexibility can be imparted to enable bending according to the back surface shape of the operation panel.
In addition, light transmittance is imparted to the base material layer and the plurality of detection electrodes of the capacitance sensor sheet, a gap is formed between the capacitance sensor sheet and the backup material, and the backup material is separated from the light source. It is possible to make a light guide that irradiates the capacitive sensor with the light beam.

Moreover, an elastic adhesive material can also be formed by sticking a double-sided adhesive layer to both sides of a foamed sponge.
It is also possible to form the elastic adhesive by sticking the double-sided adhesive layers to both sides of the elastic rubber.
Furthermore, it is also possible to form the elastic adhesive by sticking the double-sided pressure-sensitive adhesive layers to both sides of the foamed resin film.

  Here, the capacitance sensor sheet in the claims is a type in which a plurality of X detection electrodes and Y detection electrodes of the pattern layer are arranged on either the front or back surface of the base material layer, on the surface of the base material layer. A type in which a plurality of X detection electrodes in the pattern layer are arranged, a plurality of Y detection electrodes in the pattern layer are arranged on the back surface of the base material layer, and a plurality of X detection electrodes in the pattern layer are arranged in the first base material layer There is a type in which a plurality of Y detection electrodes of the pattern layer are arranged on the second base material layer, but it is not particularly limited.

  The backup material may be any structure that can support the capacitance sensor sheet, and includes at least a plate-shaped or frame-shaped support plate, a light guide, and the like. In addition, the elastic adhesive is not particularly limited, and is formed into a frame shape, a thin linear shape, a paper piece shape, or the like as necessary. The type and number of light sources can be increased or decreased as necessary.

  According to the present invention, if the capacitance sensor sheet and the backup material are bonded by an elastic adhesive to form a module, and the capacitance sensor sheet of this modularized module product is brought close to the operation panel, A capacitive input device can be obtained. Since the elastic adhesive presses the capacitance sensor sheet toward the operation panel, the operation panel and the capacitance sensor sheet come close to each other, and the capacitance sensor sheet comes into close contact with the operation panel without any gap, or a slight gap is left. And will face each other. Therefore, it is possible to suppress air from flowing in between the operation panel and the capacitance sensor sheet, thereby preventing air from being accumulated.

  According to the present invention, by bringing the operation panel and the capacitance sensor sheet close to each other, there is an effect that it is possible to suppress at low cost that air is interposed between the operation panel and the detection trouble. In addition, the presence of air can be suppressed without using a large facility.

  According to the invention described in claim 2, even if the back surface of the operation panel is curved or irregularities are formed on the back surface, the capacitance sensor sheet can be flexibly adapted to the back surface of the operation panel. Can be approached. Therefore, it is possible to prevent a large gap from being generated between the operation panel and the capacitance sensor sheet.

  According to the invention described in claim 3, it is possible to ensure the convenience of operation of the capacitance sensor sheet by illuminating the detection electrode and the operation panel of the capacitance sensor sheet, and to improve the design and decoration. Can do. Also, if an air gap is defined by interposing an elastic adhesive between the capacitance sensor sheet and the light guide, light scattering and light leakage associated with the contact between the capacitance sensor sheet and the light guide can be prevented. It becomes possible to appropriately irradiate light from the light guide in the direction of the capacitance sensor.

  Further, according to the invention described in claim 4, it is easy to assemble the capacitance sensor sheet and the backup material, and it can be easily bonded without individually applying an adhesive or the like to the capacitance sensor sheet or the backup material. Can be modularized. In addition, the foamed sponge of elastic adhesive is excellent in elasticity and compressibility and absorbs some dimensional errors, so a capacitance sensor sheet is suitable for the operation panel without special consideration for dimensional accuracy with the surroundings. It becomes possible to approach.

1 is a partial cross-sectional explanatory view schematically showing an embodiment of a capacitive input device according to the present invention. It is a plane explanatory view showing typically the capacitance sensor sheet in the embodiment of the capacitance type input device according to the present invention. It is a section explanatory view showing typically the capacitance sensor sheet in the embodiment of the capacitance type input device concerning the present invention. It is a plane explanatory view showing typically the elastic adhesive material in the embodiment of the capacitive input device according to the present invention. It is explanatory drawing which shows typically the elastic adhesive material in embodiment of the electrostatic capacitance type input device which concerns on this invention. It is perspective explanatory drawing which shows an information communication apparatus typically. It is a fragmentary sectional view showing typically the conventional capacitance type input device.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A capacitive input device 10 according to the present embodiment includes a front panel 11 approaching a user's finger as shown in FIGS. A flexible capacitance sensor sheet 12 for detecting a change in capacitance between a finger approaching the front panel 11 and the X detection electrode 16 or the Y detection electrode 19, and the capacitance sensor sheet 12 And a light guide 22 facing the back side opposite to the facing surface facing the front panel 11 of the front panel 11, and the capacitive sensor sheet 12 and the light guide 22 are bonded by an elastic adhesive 25 to form a module. I have to.

  As shown in FIG. 1, the front panel 11 is formed, for example, on a transparent flat plate having optical transparency, and is built into the housing of the information communication device 1 so that the user's finger is pressed against the surface. On the back surface of the front panel 11, a light-transmitting decorative layer and a light-shielding layer that partially shields light rays are selectively laminated. The front panel 11 is formed as a flat plate, or a light-transmitting curved plate or the like as necessary, and a necessary number of concave portions and convex portions are provided on the back surface.

  As shown in FIGS. 1 to 3, the capacitance sensor sheet 12 includes first and second base material layers 13 and 13 </ b> A that face each other, and a practical area excluding the peripheral portion of the first base material layer 13. The conductive X pattern layer 15 is laminated and formed, and the conductive Y pattern layer 18 is laminated and formed in the practical area excluding the peripheral portion of the second base material layer 13A. It is adhesively fixed and faces the back surface of the front panel 11.

  The first and second base material layers 13 and 13A are formed in a planar rectangular shape by, for example, polyethylene terephthalate having excellent heat resistance and strength, a transparent film made of polycarbonate, and the like, and are provided with insulating properties and flexibility. The first base material layer 13 is positioned below and opposes the second base material layer 13A, and an elongated tail portion 14 is formed to protrude from the rear periphery, and this tail portion 14 is attached to and detached from a control device (not shown). Connect freely.

  The X pattern layer 15 is formed by including a plurality of X detection electrodes 16 arranged in the X direction and lead lines 17 for the plurality of X detection electrodes 16. The plurality of X detection electrodes 16 are arranged in a row in the surface Y direction of the first base material layer 13 and arranged in the X direction at a predetermined interval. Most of the plurality of X detection electrodes 16 are formed in a thin film having a substantially diamond pattern in a plan view, and the remaining X detection electrodes 16 positioned at the ends of the rows are formed in a thin film having a substantially half diamond pattern in a plan view.

  Among the plurality of X detection electrodes 16 arranged in the Y direction, a conductive thin and low resistance lead line 17 is electrically overlapped and connected to the peripheral edge of the surface of the terminal X detection electrode 16. 17 extends from the tail portion 14 of the first base material layer 13 and is electrically connected to the control device.

  Such an X pattern layer 15 is obtained by screen-printing a plurality of X detection electrodes 16 on the surface of the first base material layer 13 with a light-transmitting conductive ink (for example, a conductive polymer), and drying and curing. Formed transparently, a silver paste or the like is screen-printed on the surface of the first base material layer 13 and dried and cured to form a plurality of lead lines 17.

  The Y pattern layer 18 includes a plurality of Y detection electrodes 19 arranged in the Y direction, and lead lines 20 for the plurality of Y detection electrodes 19. The plurality of Y detection electrodes 19 are connected in a row in the surface X direction of the second base material layer 13A and arranged in the Y direction at a predetermined interval. Most of the plurality of Y detection electrodes 19 are formed in a thin film having a substantially diamond pattern in plan view, and the remaining Y detection electrodes 19 located at the ends of the columns are formed in a thin film having a substantially half diamond pattern in plan view.

  Of the plurality of Y detection electrodes 19 arranged in the X direction, a conductive thin and low resistance lead line 20 is electrically overlapped and connected to the peripheral edge of the surface of the terminal Y detection electrode 19. Extends from the peripheral edge of the second base material layer 13A to the rear peripheral edge of the first base material layer 13 through a through hole, and extends to the tail portion 14 of the first base material layer 13 to form a control device. Conductive connection is established.

  Such a Y pattern layer 18 is made transparent by screen-printing a plurality of Y detection electrodes 19 on the surface of the second base material layer 13A with a light-transmitting conductive ink (conductive polymer or the like), and drying and curing. Formed, a silver paste or the like is screen-printed on the surface of the second base material layer 13A, and dried and hardened to form a plurality of drawing lines 20.

  As shown in FIG. 1, the light guide 22 guides light rays (see arrows in FIG. 1) incident on the peripheral surface from a light source 23 such as an adjacent LED in the internal XY direction and irradiates the capacitive sensor sheet 12. The front panel 11 and the capacitance sensor sheet 12 are illuminated so as to function for convenience of operation.

  The light guide 22 is formed into a flat plate having a size corresponding to the capacitance sensor sheet 12 using, for example, a light guide polycarbonate resin, acrylic resin, silicone rubber, fluorine rubber, or the like. A plurality of diffusion patterns 24 for diffusing and irradiating light beams guided to the outside are arranged and printed on the opposite surface, that is, the front surface facing the back surface.

  As shown in FIGS. 1, 4, and 5, the elastic adhesive 25 includes a compression-deformable foamed sponge 26 formed on a flat plate having a substantially groove shape, for example. A double-sided adhesive layer 27 made of an adhesive tape or the like is formed by adhering to each other. Bonded with a gap in between.

  Such an elastic adhesive 25 causes the capacitance sensor sheet 12 to be in close contact with the back surface side of the front panel 11 without a gap by a relatively small elastic action, and a gap is provided between the capacitance sensor sheet 12 and the light guide 22. 28, the electrostatic capacitance sensor sheet 12 and the light guide 22 are brought into a non-contact relationship to prevent unnecessary light scattering (light leakage) due to contact.

  In the above configuration, when the capacitive input device 10 is assembled, the capacitive sensor sheet 12 and the light guide 22 are bonded together by an elastic adhesive 25 to form a module, and the capacitance of the modularized module product. If the sensor sheet 12 is brought close to the back surface of the front panel 11, the capacitive input device 10 can be assembled.

  At this time, since the double-sided adhesive layers 27 are respectively adhered to the front and back surfaces of the foamed sponge 26 of the elastic adhesive material 25, the assembly is really easy, and an adhesive or the like is particularly applied to the capacitance sensor sheet 12 or the light guide 22. Even if it is not applied, it can be easily bonded. In addition, since the elastic adhesive 25 appropriately presses the capacitance sensor sheet 12 against the back surface of the front panel 11, the capacitance sensor sheet 12 comes into close contact with the back surface of the front panel 11 without a gap. Therefore, it is possible to prevent air from flowing into a large gap between the front panel 11 and the capacitance sensor sheet 12 and to prevent an air pool that adversely affects the appearance.

  Further, since the pressing force of the elastic adhesive 25 is small, the possibility that a large pressing force acts on the front panel 11 and the capacitance sensor sheet 12 to damage the front panel 11 and the capacitance sensor sheet 12 is effectively eliminated. can do. In addition, since the capacitance sensor sheet 12 bends, even if the back surface of the front panel 11 is curved or a concave or convex portion is formed on the back surface, the capacitance depends on the shape of the back surface of the front panel 11. The sensor sheet 12 is flexible and appropriately bent and closely contacts. Therefore, it is possible to effectively prevent a large gap from being generated between the front panel 11 and the capacitance sensor sheet 12 and air from flowing into the gap.

  When the capacitance-type input device 10 is assembled and the light source 23 emits light, light rays are incident from the peripheral surface of the light guide 22 and guided in the X and Y directions. The capacitance sensor sheet 12 is irradiated with diffusion. At this time, since the gap 28 is defined between the capacitance sensor sheet 12 and the light guide 22 by the elastic adhesive 25 interposed as a spacer between the capacitance sensor sheet 12 and the light guide 22, The light beam is appropriately irradiated in the direction of the capacitance sensor sheet 12 without irregular reflection.

  The light beam applied to the capacitance sensor sheet 12 passes through the first and second base material layers 13 and 13A, the X detection electrode 16, the Y detection electrode 19, and the transparent adhesive sheet 21 of the capacitance sensor sheet 12. The X detection electrode 16, the Y detection electrode 19, and the front panel 11 of the capacitance sensor sheet 12 are illuminated respectively.

  In such a capacitive input device 10, the user's finger is pressed against the surface of the front panel 11, and the finger is placed on the X detection electrode 16 of the selected X pattern layer 15 or the Y detection electrode 19 of the Y pattern layer 18. When approaching and facing each other, the capacitance between the fingers changes, and this change in capacitance is detected and output to the control device, which contributes to the operation of the information communication device 1.

  According to the above configuration, the capacitance sensor sheet 12 is pressed against the back surface of the front panel 11 by the elastic adhesive 25 so as to be in close contact with the gap, so that air flows into the gap between the front panel 11 and the capacitance sensor sheet 12. Therefore, the detection sensitivity can be stabilized without causing a decrease in detection sensitivity. In addition, since the foamed sponge 26 of the elastic adhesive 25 is excellent in elasticity and compressibility and can absorb some dimensional errors, the positional relationship with the peripheral components of the information communication device 1 and dimensional accuracy are not particularly considered. The capacitance sensor sheet 12 can be brought into pressure contact with the front panel 11 to be brought into close contact therewith.

  Further, since the conventional adhesive sheet 30 that is inconvenient to handle does not need to be used in close contact with the capacitance sensor sheet 12, smooth, rapid, and easy assembly work can be greatly expected. Furthermore, it is not necessary to form a vacuum environment with a vacuum pump or the like, and to close the capacitance sensor sheet 12 to the front panel 11 in a vacuum environment, so that large-scale facilities and the like can be omitted, and cost reduction can be achieved. It becomes possible.

  In the above embodiment, the elastic adhesive 25 is formed by adhering the double-sided adhesive layer 27 to both the front and back surfaces of the foamed sponge 26, but the present invention is not limited to this. For example, the elastic adhesive 25 may be formed by adhering the double-sided adhesive layers 27 on both the front and back surfaces of a thin foamed resin film.

  Further, a plurality of linear elastic adhesives 25 may be arranged and bonded between the peripheral edge of the capacitance sensor sheet 12 and the peripheral edge of the light guide 22. In addition, as long as the transmission of light is not hindered, a necessary number of elastic adhesives 25 may be bonded to a portion other than the peripheral portion of the capacitance sensor sheet 12. For example, the elastic adhesive 25 can be bonded between the X detection electrode 16 and the routing line 17, between the Y detection electrode 19 and the routing line 20, or the like. Furthermore, an elastic support material may be interposed between the capacitance sensor sheet 12 and the light guide 22 if they do not hinder the transmission of light.

  The capacitance-type input device according to the present invention can be used in the manufacturing field of audio equipment, home electric appliances including videophones, portable equipment, computer equipment, information communication equipment, automotive in-vehicle equipment, electronic equipment, and the like.

1 Information Communication Equipment 10 Capacitive Input Device 11 Front Panel (Operation Panel)
12 Capacitance sensor sheet 13 First base material layer (base material layer)
13A Second base material layer (base material layer)
15 X pattern layer (pattern layer)
16 X detection electrode (detection electrode)
18 Y pattern layer (pattern layer)
19 Y detection electrode (detection electrode)
22 Light guide (backup material)
23 Light source 25 Elastic adhesive material 26 Foam sponge 27 Double-sided adhesive layer 28 Gap

Claims (4)

A light-transmitting operation panel approaching the conductor, a capacitance sensor sheet for detecting a change in capacitance between the conductor approaching the operation panel and the detection electrode of the pattern layer, and the capacitance sensor Including a backup material provided on the non-facing surface side opposite to the facing surface facing the operation panel of the sheet,
At least the non-facing surface periphery of the capacitance sensor sheet and the backup material are bonded with a compressible and deformable elastic adhesive to make a module, and the capacitance sensor sheet is brought closer to the operation panel with the elastic adhesive. Capacitance type input device characterized by the above.   The capacitance sensor sheet includes an insulating base material layer facing the back surface of the operation panel, and a pattern layer in which at least a plurality of detection electrodes are arranged on the base material layer, and the base material layer is flexible. The capacitance-type input device according to claim 1, wherein the capacitance-type input device can be bent according to the shape of the back surface of the operation panel.   Each of the base material layer and the plurality of detection electrodes of the capacitance sensor sheet is provided with light transmittance, and a gap is formed between the capacitance sensor sheet and the backup material. The capacitance-type input device according to claim 2, wherein a light guide is used to irradiate the capacitance sensor.   The capacitive input device according to claim 1, 2, or 3, wherein the elastic adhesive is formed by adhering a double-sided adhesive layer to both sides of the foamed sponge.

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