JP2009117222A - Movable contact body, and switch using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a movable contact body and a switch using the movable contact capable of obtaining light click feeling and operating at suitable touch regarding the movable contact body used for operations of various electronic devices and the switch using the same movable contact. <P>SOLUTION: A base sheet 21 is made of a TPU resin film, the approximately dome-shaped movable contact 3 opened downward is adhesively retained by an adhesive layer 2 formed on the whole lower surface of the base sheet 21, and the movable contact body 17 is formed by firmly fixing a cylindrical pushing protuberance 24 made of a TPU resin of hardness lower than the hardness of the base sheet 21 at an upper surface position of the base sheet 21 corresponding to an approximately dome-shaped top section of the movable contact 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a movable contact body used for an operation panel of various electronic devices, and a switch using the same.

  In recent years, various electronic devices have been realized by arranging a substantially dome-shaped movable contact on the lower surface of the base sheet because it is preferable to realize a small and thin size and to obtain a light click feeling during operation. In many cases, a movable contact body is arranged on the upper surface of a wiring board having a fixed contact, and a switch is configured by the movable contact and the fixed contact.

  A conventional movable contact body and switch used in such an electronic device will be described with reference to FIGS. FIG. 4 is a cross-sectional view of a conventional movable contact body, and FIG. 5 is a cross-sectional view of the switch in the mounted state.

  In FIG. 4, 1 is a base sheet made of a polyethylene terephthalate (hereinafter referred to as PET) resin film having an adhesive layer 2 on the lower surface and formed in a predetermined shape, and 3 is an elastic metal formed in a substantially dome shape with an opening on the lower surface. The movable contact 3 is a thin plate, and a plurality of movable contacts 3 are adhered to the upper surface of the substantially dome shape by the adhesive layer 2 of the base sheet 1 and held at a predetermined position.

  Reference numeral 4 denotes a cylindrical pressing protrusion made of PET resin fixed to the upper surface of the base sheet 1 and fixed to the position corresponding to the substantially dome-shaped apex portion of each movable contact 3 with an adhesive 5.

  As the adhesive 5, an ultraviolet curable adhesive made of urethane acrylate is used in order to firmly fix the pressing protrusion 4 made of PET resin to the base sheet 1 made of PET resin. Resin layers 1 </ b> A and 4 </ b> A made of an ester resin are provided on the fixing surfaces of both pressing protrusions 4 to constitute a movable contact body 7.

  The movable contact body 7 configured in this way is protected by the adhesive layer 2 on the lower surface of the base sheet 1 in order to protect the lower surface of the movable contact 3 and prevent foreign matter from adhering to the adhesive layer 2 on the lower surface of the base sheet 1. As shown in FIG. 4, the entire bottom surface of the base sheet 1 is covered with the separator 6, and the movable contact 3 is formed between the base sheet 1 and the separator 6. It is made into the form inserted | pinched between, and conveyance and storage are made.

  When the movable contact body 7 is used, the separator 6 is peeled off, and as shown in FIG. 5, a plurality of pairs of fixed contacts with a central fixed contact 8A and an outer fixed contact 8B as a pair at positions corresponding to the movable contacts 3 are provided. The contact 8 is attached to the wiring board 10 having the upper surface disposed on the adhesive layer 2 on the lower surface of the base sheet 1 and used.

  In the use state, the movable contact 3 is placed on the outer fixed contact 8B so that the substantially dome-shaped apex faces the center fixed contact 8A, and the movable contact 3 is paired with the pair of movable contacts 3. The fixed contact 8 constitutes one switch. As a whole, the operation panel switch includes a plurality of switches. In addition, 13 shown with the broken line in FIG. 5 is the operation button of the electronic device arrange | positioned in the position corresponding to the upper direction of the press protrusion 4 on the base sheet 1. FIG.

  In the above configuration, when the operation button 13 is pressed with a finger or the like, the operation button 13 is lowered downward, a pressing force is applied to the columnar pressing protrusion 4 in contact with the operation button 13, and the base sheet 1 is moved. The pressing force is applied to the substantially dome-shaped apex portion of the movable contact 3 through.

  When the force becomes larger than the pressing force at which the movable contact 3 is elastically reversed, the substantially dome-shaped portion of the movable contact 3 is elastically reversed in the direction in which it swells downward with a click feeling, and the lower surface of the substantially dome-shaped apex portion is The pair of fixed contacts 8 is brought into an electrically conductive state via the movable contact 3 by contacting the opposed central fixed contact 8A.

  Further, when the pressing force applied to the operation button 13 is released, the pressing force applied to the movable contact 3 via the pressing protrusion 4 on the lower surface and the base sheet 1 is reduced, and the force is elastically reversed by the movable contact 3. When the reversal return force of the substantially domed portion is reduced, the movable contact 3 returns to the original domed shape of the original bottom opening with a click feeling, and is separated from the center fixed contact 8A and shown in FIG. The pair of fixed contacts 8 returns to an electrically disconnected state.

  Further, the pressing protrusion 4 is arranged so that the substantially dome-shaped apex portion of the movable contact 3 is always pressed even when the operation button 13 is pressed at a position deviated from the center. The click feeling generated when the movable contact 3 is reversed / returned is stabilized to obtain a good operation feeling.

  In general, PET is used as the material for the base sheet 1 and the pressing protrusion 4 of the movable contact body 7. This PET uses a relatively hard material having a breaking strength of 200 MPa to 260 MPa and a breaking elongation of 80% to 140%.

  FIG. 3 is a characteristic diagram of operation feeling in the difference between the material forming the base sheet and the pressing protrusion. The vertical axis represents the pressing force to the operation button 13, and the horizontal axis represents the moving distance of the movable contact 3 caused by the pressing force. This characteristic is referred to as a click feeling characteristic.

  As a method of evaluating this click feeling by a measured value, the pressing force (P1) at the highest point immediately before elastic reversal at the time of pressing and the maximum when the movable contact hits the lower substrate when the movable contact is in a state of elastic reversal. The difference (D) from the lower point pressing force (P2) is generally expressed as a click rate (D × P1 × 100%).

  In the figure, a characteristic X indicated by a broken line is a click feeling characteristic of a conventional example in which the material forming the base sheet and the pressing protrusion is PET. This characteristic X has a strong force to maintain the original state because the PET used for the base sheet 1 and the pressing protrusion 4 is a relatively hard material, and this force causes the pressing force when the movable contact 3 is further pushed from the elastic inversion state. On the other hand, since Xb becomes large, the click rate becomes small. As a result, the click feeling of the movable contact 3 is lowered.

  In order to prevent the click feeling from being lowered, a relatively thin base sheet 1 having a thickness of about 25 μm to 75 μm is used. If it is made thinner than this, it becomes difficult to make it thin because it may cause damage at the time of application to the wiring board 7 and the click feeling is limited.

As prior art document information related to the invention of this application, for example, Patent Document 1 and Patent Document 2 are known.
JP 2004-193047 A JP 2002-216582 A

  However, in the above-described conventional movable contact body 7 and the switch using the same, during the operation, a pressing operation is performed through the base sheet 1 made of a relatively hard PET resin film and the pressing protrusion 4, and the base on the upper surface of the movable contact 3. Since a force for deforming the sheet 1 and the pressing protrusion 4 is also required, there is a problem that the click feeling (hereinafter also referred to as a click feeling) that is lighter than that when the movable contact 3 is directly operated is reduced accordingly.

  The present invention solves such a conventional problem, and an object thereof is to provide a movable contact body that can provide a light click feeling and can be operated with a good feel, and a switch using the same. And

  In order to achieve the above object, the present invention has the following configuration.

  According to the first aspect of the present invention, the base sheet is formed of a thermoplastic polyurethane (hereinafter referred to as TPU) resin, and the pressing protrusion is formed of a material having a hardness lower than that of the base sheet. Since there is flexibility compared to PET and these deformation forces can be made small, it is possible to obtain a movable contact body that can suppress a decrease in the click feeling during pressing operation to the movable contact and can obtain a crisp and light click feeling. Has the effect of being able to

  According to a second aspect of the present invention, in the first aspect of the invention, the base sheet is made light transmissive, and an EL element is further provided between the base sheet and the movable contact, and the base sheet is made light transmissive. In this case, the operation button 13 can be illuminated by light emission of the EL element, and even when the EL element is formed on the lower surface of the base sheet, the base sheet is made of TPU and the pressing protrusion is made of a material less than the hardness of the base sheet. By forming, it has the effect | action that a light click feeling is obtained and the movable contact body which can be operated by favorable feeling can be obtained.

  The invention according to claim 3 is a switch comprising a movable contact body according to claim 1 and a base sheet attached to the substrate so that the movable contact faces the fixed contact of the substrate. A click feeling can be obtained, and a switch that can be operated with a good feel can be realized.

  As described above, according to the present invention, a light click feeling can be obtained, and an advantageous effect that a movable contact body that can be operated with a good feel and a switch using the movable contact body can be realized. .

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

  In addition, the same code | symbol is attached | subjected to the part of the structure same as the structure demonstrated in the term of background art, and detailed description is simplified.

(Embodiment)
FIG. 1 is a sectional view of a movable contact body according to an embodiment of the present invention, and FIG. 2 is a sectional view of a switch in the same mounting state.

  In the figure, reference numeral 21 denotes a base sheet made of a TPU resin film. The base sheet 21 has an adhesive layer 2 on the entire lower surface, and the adhesive layer 2 allows a movable contact 3 made of an elastic metal thin plate such as stainless steel to be positioned at a predetermined position. Adhesive is held on.

  The movable contact 3 is formed in a substantially dome shape with an opening on the lower surface, and is elastically reversed with a click feeling by a predetermined pressing force, and is substantially a dome shape with the click feeling by releasing the pressing force. It is a self-reset type that elastically recovers.

  Then, at the upper surface position of the base sheet 21 corresponding to the substantially dome-shaped apex portion of the movable contact 3 that is adhered and held by the adhesive layer 2 of the base sheet 21, for example, a TPU resin or silicone resin that is softer than the base sheet 21 is used. A pressing protrusion 24 formed by being punched into a cylindrical shape is fixed.

  In the movable contact body 17 of the present embodiment, the base sheet 21 made of a TPU resin film has a thickness of 5 μm to 100 μm, more preferably around 50 μm, for example, using JIS 605 made by Seadam Co., Ltd. having a hardness of 96 according to JIS standards. Yes. The pressing protrusion 24 is made of a TPU resin having a hardness of about 90 or a silicone resin having a hardness of about 85, which is a material having a thickness of about 100 μm to 250 μm and less than the hardness of the base sheet 21.

  As described above, the base sheet 21 and the pressing protrusion 24 of the present invention are formed of a TPU resin having a breaking strength of 2 MPa to 10 MPa and a breaking elongation of 300% to 1000%, which is more flexible than conventional PET or the like. .

  Then, the pressing protrusion 24 is fixed to the upper surface of the base sheet 21 by an ultraviolet curable adhesive 5 made of urethane acrylate, so that the movable contact body 17 is configured.

  In the movable contact body 17 configured in this manner, the separator 6 made of an insulating film subjected to a peeling process is bonded to the lower surface of the base sheet 21 by the adhesive layer 2 so as to sandwich the movable contact 3 as in the conventional case. The entire lower surface of the base sheet 21 is covered, whereby oxidation of the surface of the movable contact 3 during transportation and storage, adhesion of foreign matter, and prevention of mixing are made.

  When the movable contact body 17 is used, the separator 6 on the lower surface is peeled off as in the prior art, and the fixed contact 8 having a pair of the central fixed contact 8A and the outer fixed contact 8B on the upper surface is movable as shown in FIG. A plurality of pairs of wiring boards 10 corresponding to the positions of the contacts 3 are attached to the lower surface of the base sheet 21 by the adhesive layer 2 and put into use.

  In this state, each movable contact 3 has an outer peripheral lower end placed on the corresponding outer fixed contact 8B to be in an electrically conductive state, and a substantially dome-shaped apex portion faces the corresponding central fixed contact 8A, In a use state in which the movable contact body 17 that is configured as one switch by the combination of the pair of fixed contacts 8 and the one movable contact 3 and is adhered and held on the plurality of movable contacts 3 is attached to the wiring board 10. And an operation panel switch having a plurality of switches.

  Then, the lower surface is brought into contact with the pressing protrusion 24 on the upper surface of the base sheet 21 of the operation panel switch, and the operation button 13 indicated by a broken line is arranged above the pressing protrusion 24 to be incorporated in the electronic apparatus.

  In the operation of the movable contact body 17 incorporated in this way, first, when a pressing force is applied to the operation button 13, the pressing force is applied to the substantially dome-shaped apex portion of the movable contact 3 via the pressing protrusion 24 and the base sheet 21. When the predetermined pressing force is exceeded, the substantially dome-shaped portion of the movable contact 3 is elastically reversed to a state where it swells downward with a click feeling, and the lower surface of the substantially dome-shaped apex portion contacts the lower central fixed contact 8A. And become conductive.

  When the pressing force is released, the substantially dome-shaped portion of the movable contact 3 is elastically restored with a click feeling, and the state between the central fixed contact 8A and the outer fixed contact 8B is shown in FIG. It returns to the original state shown.

  Next, the click feeling characteristic in the difference in the material which forms a base sheet and a press protrusion using FIG. 3 is demonstrated. As described above, the characteristic X indicated by the broken line indicates that the material forming the base sheet and the pressing protrusion is a conventional example of PET, and the characteristic Y indicated by the solid line forms the pressing protrusion with the base sheet according to one embodiment of the present invention. All the materials to be used are the click feeling characteristics of TPU.

  Regarding the characteristic X of the conventional example, since the PET used for the base sheet 1 and the pressing protrusion 4 is a relatively hard material, the pressing force has a large lowest point Xb, and thus the click feeling of the movable contact 3 is lowered.

  On the other hand, since the TPU used for the base sheet 21 and the pressing protrusion 24 is a relatively soft material, the characteristic Y is the lowest when the operation button 13 is pressed and the movable contact 3 is elastically reversed and further pushed. The point Yb becomes smaller, and therefore the click rate of the movable contact 3 becomes larger. As a result, a good click feeling can be obtained. This indicates that it is possible to achieve a characteristic close to a click feeling when the movable contact 3 is a single body.

  Further, the highest point Ya and the lowest point Yb can be moved by changing the hardness and thickness of the pressing protrusion 4, and a desired click feeling can be obtained.

  As is clear from each characteristic, when the click rate of the conventional example is set to 1, the click rate of the present embodiment can be as high as about 1.2 times compared to the conventional example, and the operation feeling is better than that of the conventional example. You can see that

  As described above, according to the present embodiment, the base sheet 21 and the pressing protrusion 24 are formed of flexible TPU resin, so that a light click feeling can be obtained and a movable operation is possible with a good feel. A contact body and a switch using the contact body can be obtained.

  In the present embodiment, the movable contact body 17 makes the base sheet 21 light-transmitting, and prints on the lower surface of the base sheet 21 to transmit a light-transmitting electrode layer, a light emitter layer, a dielectric layer, a back electrode layer, and It is also possible to provide an EL element in which an insulating layer covering these is laminated. In this case, since the light emission of the EL element illuminates the operation button from below, it is possible to easily identify and operate the operation unit even when the surrounding is dark, for example.

  The movable contact body and the switch using the same according to the present invention are light and can be operated with a good click feeling, and are useful for operating various electronic devices.

Sectional drawing of the movable contact body by one embodiment of this invention Cross section of the switch Click feeling characteristic diagram of the present invention and the conventional switch Cross section of a conventional movable contact body Cross section of the switch

Explanation of symbols

2 Adhesive layer 3 Movable contact 5 Adhesive 6 Separator 21 Base sheet 24 Pressing protrusion

Claims (3)

A base sheet made of an insulating film having an adhesive layer on the lower surface, a movable contact having a substantially dome-shaped upper surface adhered to the adhesive layer of the base sheet, and the dome-shaped apex corresponding to the movable contact A pressing protrusion fixed to the upper surface position of the base sheet,
A movable contact body in which the base sheet is formed of a thermoplastic polyurethane resin, and the pressing protrusion is formed of a material having a hardness equal to or lower than the hardness of the base sheet. The movable contact body according to claim 1, wherein the base sheet is light-transmitting, and an EL element is further provided between the base sheet and the movable contact. A movable contact body according to claim 1 and a substrate having a fixed contact, and the base sheet is attached to the substrate so that the movable contact of the movable contact body faces the fixed contact of the substrate. Switch.

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