JP2008152954A - Membrane switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a membrane switch capable of preventing malfunction of a switch, without controlling the elongation of the sheet member of the membrane switch facing to the panel member, when the ambient temperature rises. <P>SOLUTION: The switch comprises a membrane switch (12), having a pair of sheet members (12a, 12b) disposed respectively opposite to a pair of electrodes (12c, 12d); a panel member (10) whose coefficient of thermal expansion is different from that of the sheet members (12a, 12b); and a separation member (11), provided in between the sheet member (12a) facing the panel member (10) and the panel member (10) for separating the sheet member (12a) facing to the panel member (10) and the panel member (10) so that they can move relatively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a membrane switch.

  The membrane switch is a switch composed of a pair of sheets with a pair of contact electrodes facing each other. Such membrane switches are used for various applications such as panel switches and pressure sensitive switches for vehicle seats.

  Here, in order to improve the visibility of the display of the panel switch and improve the design, a panel made of an electroluminescent element capable of displaying characters or figures by self-emission is attached to the membrane switch, with electroluminescence Membrane switches are widely known. Such a membrane switch with electroluminescence is used as a panel switch for a vehicle, for example, and an input operation is performed on a device mounted on the vehicle.

  One of the pair of sheets constituting the membrane switch is attached to a panel made of an electroluminescence element (see, for example, Patent Document 1).

JP 2006-147505 A

  5 and 6 are cross-sectional views of a conventional membrane switch with electroluminescence in the stacking direction. First, a description will be given with reference to FIG. The membrane switch with electroluminescence is configured by laminating a membrane switch 18 and a panel 19 made of an electroluminescence element. The membrane switch 18 includes a pair of resin sheets 18a and 18b. A pair of contact electrodes 18c and 18d are provided on the surfaces of the pair of sheets 18a and 18b, respectively. The pair of sheets 18a and 18b are arranged with a spacer interposed therebetween so that the pair of contact electrodes 18c and 18d face each other. A predetermined gap is formed between the pair of electrodes 18c and 18d arranged to face each other. Of the pair of sheets 18 a and 18 b constituting the membrane switch 18, the sheet 18 b facing the panel 19 is attached to the panel 19 and integrated with the panel 19.

  Next, a description will be given with reference to FIG. When the ambient temperature rises, both the pair of sheets 18 a and 18 b constituting the membrane switch 18 tend to extend. However, the panel 19 restricts the stretching of the sheet 18 b attached to the panel 19. On the other hand, the other sheet 18a not attached to the panel 19 expands due to an increase in ambient temperature. Then, as shown in FIG. 6, the expanded sheet 18a is curved toward the sheet 18b attached to the panel 19, whereby a pair of contact electrodes 18c provided on the sheets 18a and 18b, respectively. The switch 18d may come into contact with the switch, causing a malfunction of the switch.

  In particular, in the panel switch for vehicles, since the environmental temperature range is wide, there existed a subject that there was a large possibility of malfunctioning.

  The present invention includes a membrane switch having a pair of sheet members each provided with electrodes and arranged so that the electrodes face each other, a panel member having a coefficient of thermal expansion different from that of the sheet members, and the pair of sheet members A separation member provided between the sheet member facing the panel member and the panel member for separating the sheet member facing the panel member and the panel member in a relatively movable manner. It is characterized by providing.

  According to such a configuration, the sheet member facing the panel member and the panel member of the pair of sheet members constituting the membrane switch are relatively movable, so even if the ambient temperature rises, the panel member faces The stretching of the sheet member to be performed is not restricted, and the malfunction of the switch can be prevented.

  In the switch according to the present invention, it is preferable that the separation member is a particle having a diameter of 0.01 mm to 0.1 mm.

  According to this configuration, smooth relative movement between the sheet member facing the panel member and the panel member can be realized by using fine particles.

  In the switch of the present invention, it is preferable that the separation member is ceramic particles.

  In the switch according to the present invention, it is preferable that the panel member is a panel member made of an electroluminescence element.

  In particular, when a panel made of an electroluminescent element is used in combination with a membrane switch, the above problem often occurred. However, according to the configuration of the present invention, the panel made of an electroluminescent element and the membrane switch are relatively Therefore, the above-mentioned problem does not occur.

  The switch according to the present invention further includes a housing that houses a laminate of the membrane switch, the separation member, and the panel member, and the laminate is provided on a wall surface of the housing facing an outer edge of the laminate. It is preferable that the elastic member is pressed in a direction perpendicular to the stacking direction and fixed in the housing.

  According to such a configuration, the laminated body of the membrane switch, the separating member, and the panel member can be positioned and fixed in the housing. Even if the ambient temperature rises and the sheet member of the membrane switch expands thermally, the expansion can be absorbed by the elastic member.

  According to the present invention, even if the ambient temperature rises, the stretching of the sheet member facing the panel member is not restricted, and the malfunction of the switch can be prevented.

  Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  FIG. 1 is a front view of the vehicle panel switch according to the present embodiment. FIG. 2 is a cross-sectional view taken along line AA in FIG. For convenience of explanation, description will be given first with reference to FIG.

  The vehicle panel switch according to the present embodiment includes a panel 10 made of an electroluminescence element, a separation member 11 made of ceramic particles, a membrane switch 12, and a housing 13 that houses these and is assembled to an instrument panel of the vehicle, Consists of A laminated body of the panel 10, the separating member 11, and the membrane switch 12 is housed in the housing 13 in close contact in the laminating direction. An opening 14 is provided on the wall surface of the housing 13 facing the end surface in the stacking direction of the laminate, and the surface of the panel 10 can be visually recognized from the outside through the opening 14.

  FIG. 3 is an enlarged view of a portion B in FIG. Hereinafter, a description will be given with reference to FIG. The panel 10 is composed of an electroluminescence element in which an organic EL layer and an electrode made of indium oxide (ITO) or the like are laminated on a substrate such as glass. The organic EL layer has a known structure, and is composed of, for example, an electron transport layer, a light emitting layer, and a hole transport layer. By applying an AC voltage or a DC voltage to the electrodes, light emission from the organic EL layer can be obtained, and the luminance of light emission changes depending on the strength of the applied voltage.

  The membrane switch 12 includes a pair of sheets 12a and 12b. A pair of contact electrodes 12c and 12d are provided on the surfaces of the pair of sheets 12a and 12b, respectively. The pair of sheets 12a and 12b are arranged with the spacer 12e sandwiched so that the pair of contact electrodes 12c and 12d face each other. A predetermined gap D is formed between the pair of electrodes 12c and 12d arranged to face each other.

  A pair of sheet | seats 12a and 12b are formed by processing resin materials, such as a polyethylene terephthalate (PET), into a film form, for example, The thermal expansion coefficient is larger than the panel 10 which consists of an electroluminescent element. For the sheets 12a and 12b, various materials can be selected according to various conditions such as heat resistance required for the membrane switch. As a material for forming the electrodes 12c and 12d of the sheets 12a and 12b, a metal foil made of a metal such as copper or silver, a conductive paste such as a silver paste, or the like is used.

  In the membrane switch 12 of the present embodiment, when a load is applied from the sheet 12a side facing the panel 10 of the pair of sheets 12a and 12b, a portion of the sheet 12a that is not in contact with the spacer 12e is deformed, and the sheet 12a The contact electrode 12c comes into contact with the electrode 12d of the other sheet 12b and becomes conductive.

  The separation member 11 is made of fine particles. The fine particles constituting the separating member 11 are laid uniformly and thinly between the sheet 12 a facing the panel 10 and the panel 10. The sheet 12a facing the panel 10 and the panel 10 are separated by the separating member 11 so as to be relatively movable. Then, even when the ambient temperature rises, the sheet 12a facing the panel 10 is freely thermally expanded without being restricted by the panel 10 from being stretched. Therefore, the malfunction of the switch is not caused.

  In the present embodiment, the diameter of the particles constituting the separation member 11 is, for example, 0.01 mm to 0.1 mm. According to such a configuration, the distance between the sheet 12a facing the panel 10 and the panel 10 can be reduced, and the panel switch can be further reduced in thickness. Further, by using fine particles having a diameter of 0.01 mm to 0.1 mm, smooth relative movement between the sheet 12a facing the panel 10 and the panel 10 can be realized. The particle diameter is preferably smaller in the range of 0.01 mm to 0.1 mm from the viewpoint of thinning the panel switch. However, the relative movement between the sheet 12a and the panel 10 and the panel switch are preferable. Various modifications can be made within a range in which a reduction in thickness can be achieved.

  In the conventional panel switch, if the membrane switch sheet in contact with the panel has a thickness greater than or equal to a predetermined value, the surface on the opposite side of the surface in contact with the panel of the sheet in contact with the panel Then, the influence of the regulation by the panel is reduced. In the present embodiment, the sheet 12a and the panel 10 are separated so as to be relatively movable by the separation member 11 made of fine particles having a diameter of 0.01 mm to 0.1 mm. It is not necessary to make it more than the value. According to the configuration of the present embodiment, it is possible to achieve both prevention of switch malfunction and thinning of the switch.

  In the present embodiment, the separation member 11 is made of ceramic particles, for example. Note that the present invention is not limited to this, and various modifications are possible. For example, the separation member 11 may be made of particles made of plastic or the like. The types of particles constituting the separating member 11 can be variously changed within a range in which the object of separating the sheet 12a facing the panel 10 and the panel 10 so as to be relatively movable can be achieved.

  Next, the configuration of the operation switch unit 15 will be described with reference to FIG. FIG. 1 is a front view of a vehicle panel switch according to this embodiment. An operation switch unit 15 is printed on the surface of the panel 10. The operation switch unit 15 can be visually recognized from the outside through the opening 14 provided in the housing 13. A pair of electrodes 12c and 12d provided on the pair of sheets 12a and 12b constituting the membrane switch 12 are arranged on the back side of the printing surface of the operation switch unit 15 so as to correspond to the operation switch unit 15. Yes. When the operator presses the operation switch unit 15, the sheet 12 a disposed on the back side of the printing surface of the operation switch unit 15 and facing the panel 10 of the membrane switch 12 is deformed, and the contact of the sheet 12 a. The electrode 12c comes into contact with the contact electrode 12d of the other sheet 12b and becomes conductive.

  4 is a cross-sectional view taken along the line CC of FIG. As described above, the laminated body of the panel 10, the separating member 11, and the membrane switch 12 is accommodated in the housing 13. An elastic member 17 is provided on a wall surface 16 of the housing 13 facing the outer edge of the laminate. The laminated body is pressed and fixed in the housing 13 by the elastic member 17 in a direction perpendicular to the laminating direction. According to such a configuration, even when the ambient temperature rises and the pair of sheets 12 a and 12 b constituting the membrane switch 12 is thermally expanded, the expansion can be absorbed by the elastic member 17.

  In the present embodiment, the shape of the elastic member 17 is, for example, a semi-cylindrical shape, but is not limited to this, and various changes can be made. For example, the shape of the elastic member 17 may be a columnar shape, a rectangular parallelepiped shape or a cubic shape, and various changes within a range in which the purpose of absorbing the thermal expansion of the sheets 12a and 12b can be achieved. Is possible.

  In the present embodiment, a plurality of elastic members 17 are provided on the wall surface 16 of the housing 13 facing the outer edge of the laminate. Of the outer edges of the laminate, two adjacent outer edges are in contact with a plurality of elastic members 17 provided on the wall surface 16 of the housing 13, and these elastic members 17 cause a direction perpendicular to the stacking direction. It is pressed. Of the outer edges of the laminate, the other two adjacent outer edges are in contact with the wall surface of the housing 13 on which the plurality of elastic members 17 are not provided.

  The configuration of the present embodiment is merely an example, and it is needless to say that various modifications can be made. For example, instead of the plurality of elastic members 17, a sheet made of one elastic material is attached to the wall surface 16, the elastic material sheet is brought into contact with the outer edge of the laminate, and the outer edge of the laminate is covered with the elastic material sheet. It may be an aspect of being. According to such an aspect, the fine particles constituting the separation member 11 can be reliably sealed.

  In the present embodiment, the panel 10 made of electroluminescence elements has been mainly described as being laminated on the membrane switch 12 via the separating member 11, but the present invention is not limited to this, and various modifications are possible. For example, a plate-like panel member for pressing the membrane switch 12 may be stacked on the membrane switch 12, and various panel members may be stacked on the membrane switch 12.

  In the present embodiment, the example in which the present invention is applied to a vehicle panel switch has been mainly described. However, the present invention is not limited to this, and various modifications can be made. For example, the present invention may be applied to a panel switch of a liquid crystal monitor, or the present invention may be applied to a panel switch such as a home appliance. The present invention is particularly effective when applied to a panel switch used in an environment where the change in ambient temperature is large.

It is a front view of the panel switch which concerns on embodiment of this invention. It is a figure which shows the AA sectional view of the panel switch which concerns on embodiment of this invention. It is an enlarged view of B part which is the principal part of the panel switch which concerns on embodiment of this invention. It is a figure which shows the CC line cross section of the panel switch which concerns on embodiment of this invention. It is a figure which shows the cross section of the lamination direction of the conventional panel switch. In the conventional panel switch, it is a figure showing the deformation | transformation by the thermal expansion of the sheet | seat which comprises a membrane switch, when atmospheric temperature rises.

Explanation of symbols

  10 Panel, 11 Separating member, 12 Membrane switch, 12a, 12b Sheet, 12c, 12d Electrode, 12e Spacer, 13 Housing, 14 Opening part, 15 Switch part for operation, 16 Wall surface, 17 Elastic member, 18 Membrane switch, 18a, 18b sheet, 18c, 18d electrode, 18e spacer, 19 panel.

Claims (5)

Membrane switches each having an electrode and having a pair of sheet members arranged so that the electrodes face each other;
A panel member having a different coefficient of thermal expansion from the sheet member;
Of the pair of sheet members, the sheet member facing the panel member and the panel member are provided, and the sheet member facing the panel member and the panel member are separated so as to be relatively movable. And a separating member. The switch according to claim 1,
The switch is characterized in that the separation member is a particle having a diameter of 0.01 mm to 0.1 mm. The switch according to claim 1 or 2,
The switch, wherein the separation member is ceramic particles. The switch according to any one of claims 1 to 3,
The panel member is a panel member made of an electroluminescence element. The switch according to any one of claims 1 to 4,
A housing that houses a laminate of the membrane switch, the separation member, and the panel member;
The switch is characterized in that the laminated body is pressed in a direction perpendicular to the laminating direction by an elastic member provided on a wall surface of the housing facing an outer edge of the laminated body and fixed in the housing.

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