JP2009146815A - Sheet switch - Google Patents

Sheet switch Download PDF

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Publication number
JP2009146815A
JP2009146815A JP2007324813A JP2007324813A JP2009146815A JP 2009146815 A JP2009146815 A JP 2009146815A JP 2007324813 A JP2007324813 A JP 2007324813A JP 2007324813 A JP2007324813 A JP 2007324813A JP 2009146815 A JP2009146815 A JP 2009146815A
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JP
Japan
Prior art keywords
light
sheet
light guide
contact member
movable contact
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2007324813A
Other languages
Japanese (ja)
Inventor
Tadashi Imamura
正 今村
Original Assignee
Hosiden Corp
ホシデン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hosiden Corp, ホシデン株式会社 filed Critical Hosiden Corp
Priority to JP2007324813A priority Critical patent/JP2009146815A/en
Publication of JP2009146815A publication Critical patent/JP2009146815A/en
Application status is Pending legal-status Critical

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Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin sheet switch having a uniform and stable quantity of light to be reflected to the outside. <P>SOLUTION: The sheet switch 10 includes a substrate 1 on which a fixed contact 2 is provided, a domed movable contact member 4 arranged to cover the fixed contact 2 and formed to contact the fixed contact 2 when receiving downward thrust, a light emitting element 6 provided on the substrate 1, a light guide sheet 5 provided to cover the movable contact member 4 for guiding light reflected from the light emitting element 6, and a plurality of light reflecting parts 7 with a predetermined thickness which are arranged between the light guide sheet 5 and the movable contact member 4 to form a space S partially between the light guide sheet 5 and the movable contact member 4, for reflecting the light guided by the light guided sheet 5. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sheet switch having a lighting function.

  The sheet switch includes a substrate on which a fixed contact is provided, and a dome-shaped movable contact member that is disposed so as to cover the upper side of the fixed contact and is configured to contact the fixed contact by receiving a pressing force from above. It is prepared for. When an illumination function is added to such a sheet switch, a light-emitting element is provided on the substrate, and a light guide sheet that guides light emitted from the light-emitting element is placed on the dome-shaped movable contact member via the adhesive sheet. The light guide sheet is attached to the substrate and the dome-shaped movable contact member. As a result, the light guided through the light guide sheet is reflected at the interface between the light guide sheet, the substrate and the adhesive sheet, and the sheet switch shines.

  In addition, the sheet switch described in Patent Document 1 includes a reflection unit for reflecting light guided to the light guide sheet between the adhesive sheet and the light guide sheet above the movable contact member. The reflective portion is formed of a reflective sheet material or a reflective coating film having a high reflectance such as white or silver. Thereby, the light guided through the light guide sheet shines greatly above the movable contact member due to the reflective action of the reflective sheet material or the reflective coating film.

JP 2007-87749 A

  Since the sheet switch having the illumination function described in Patent Document 1 includes an adhesive sheet for adhering the light guide sheet to the lower substrate and the movable contact member, only the thickness of the adhesive sheet (for example, 50 μm) is provided. There is a problem that the sheet switch becomes thick.

Moreover, the sheet switch of the structure which provided the projection-like light reflection part instead of the reflection part formed with the above reflective sheets and reflective coating films can also be assumed. FIG. 4A is a cross-sectional view of such a sheet switch 30. As shown in the figure, the sheet switch 30 is configured by mounting various components on a substrate 31 on which a fixed contact 32 and a circuit pattern 33 are provided. Specifically, a dome-shaped movable contact member 34 provided in contact with the circuit pattern 33 is disposed so as to cover the upper side of the fixed contact 32. The substrate 31 in a state where the movable contact member 34 is provided is provided with an adhesive sheet 35 so as to cover the substrate 31 and the movable contact member 34, and further provided on the substrate 31 so as to cover the adhesive sheet 35. A light guide sheet 36 that guides light emitted from the light emitting element 37 is provided. In addition, a plurality of light reflecting portions 38 that reflect light guided to the light guide sheet 36 are partially provided on the surface of the light guide sheet 36 facing the adhesive sheet 35 above the movable contact member 34. It has been. That is, above the movable contact member 34, the light guide sheet 36 to which a plurality of light reflecting portions 38 are added is disposed via the adhesive sheet 35 therebetween. In addition, each light reflecting portion 38 has a predetermined thickness and is provided between the light guide sheet 36 and the adhesive sheet 35, so that the light reflector 38 is partially provided between the light guide sheet 36 and the adhesive sheet 35. A space S is formed.
As described above, in the sheet switch 30 shown in FIG. 4A, the light propagating through the light guide sheet 36 has a plurality of light reflecting portions 38 at the central portion C of the sheet switch 30 as indicated by broken line arrows. However, since there is no member in contact with the light guide sheet 36 in the peripheral portion P or the like, total reflection is repeatedly propagated inside.

FIG. 4B is a cross-sectional view showing a state in which the pressing force from above is applied to the central portion C in such a sheet switch 30. When a pressing force from above is applied to the central portion C of the sheet switch 30, the movable contact member 34 comes into contact with the fixed contact 32 on the substrate 31, and the fixed contact 32 and the circuit pattern 33 cause the movable contact member 34 to move. Through. In this state, the light guide sheet 36, the adhesive sheet 35, and the dome-shaped movable contact member 34 are integrally pushed down, so that the light guide sheet 36 and the adhesive sheet 35 are located at the peripheral portion P of the sheet switch 30. Contact. Thus, when the light guide sheet 36 and the adhesive sheet 35 come into contact with each other, the light guide sheet 36 at the contact portion does not cause total reflection of light propagating through the inside, and the light guide sheet 36 and the adhesive sheet Light goes out toward 35, and light reflection occurs on the surface of the pressure-sensitive adhesive sheet 35 as indicated by a broken-line arrow. That is, when a pressing force from above is applied to the sheet switch 30, strong reflected light from the peripheral portion P in addition to the central portion C is newly seen from the outside of the sheet switch 30.
In particular, when a white tape having a high reflectance is used as the pressure-sensitive adhesive sheet, the degree of light reflection is large between the portion where the light guide sheet 36 and the pressure-sensitive adhesive sheet 35 are in close contact with each other and the portion where the light guide sheet 36 is not in close contact. There arises a problem that unevenness occurs.

  Further, in such a sheet switch, when the adhesive sheet is of a type that is bonded by applying heat or pressure, problems such as deformation or alteration due to heat or pressure may occur in surrounding parts. .

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a thin sheet switch in which the amount of light reflected to the outside is uniform and stable.

The characteristic configuration of the seat switch according to the present invention for achieving the above object includes a substrate on which a fixed contact is provided,
A dome-shaped movable contact member which is arranged so as to cover the upper side of the fixed contact and is configured to contact the fixed contact under a pressing force from above;
A light emitting device provided on the substrate;
A light guide sheet that is provided so as to cover the upper side of the movable contact member and guides light emitted from the light emitting element;
The light guide sheet has a predetermined thickness and is provided between the light guide sheet and the movable contact member to partially form a space between the light guide sheet and the movable contact member. And a plurality of light reflecting portions for reflecting the light guided to the surface.

  According to the said characteristic structure, adhesion | attachment with a light guide sheet and the movable contact member below it is performed by the light reflection part. As a result, the pressure-sensitive adhesive sheet provided in the conventional sheet switch becomes unnecessary, and the sheet switch can be made thinner by the amount of the pressure-sensitive adhesive sheet. In addition, because the adhesive sheet is unnecessary, the surrounding parts have been affected by heat and pressure, such as deformation and alteration, which has been a problem when using adhesive sheets of the type that are bonded by applying heat or pressure. There is also an advantage that it does not occur.

Further, when a pressing force is applied to the sheet switch from above, the light guide sheet and the movable contact member are movable even in a portion where a space is formed between the light guide sheet and the movable contact member before the pressing force is applied. The contact member may come into contact. In the conventional sheet switch, since the light guide sheet and the pressure-sensitive adhesive sheet come into contact with each other in such a case, there is a problem that reflected light on the surface of the pressure-sensitive adhesive sheet in the contacted portion suddenly appears greatly.
However, in this feature configuration, since the adhesive sheet itself does not exist, a material having low reflectance is used for the movable contact member that comes into contact with the light guide sheet when a pressing force is applied to the sheet switch from above. If used, strong reflected light will not be seen even if the light guide sheet and the movable contact member come into contact with each other. Thus, conventionally, since the pressure-sensitive adhesive sheet comes into contact with the light guide sheet, there is a large unevenness in the degree of light reflection between the portion where the light guide sheet and the pressure-sensitive adhesive sheet are in close contact with each other and the portion where the light guide sheet is not in close contact. However, such a problem does not occur in the seat switch having this characteristic configuration.
Therefore, according to this characteristic configuration, it is possible to provide a thin sheet switch in which the amount of light reflected to the outside is uniform and stable.

  Another characteristic configuration of the sheet switch according to the present invention is that the light reflecting portion is formed by kneading an adhesive into a reflective agent.

  According to the above characteristic configuration, the light reflecting portion itself functions as an adhesive. Therefore, when assembling the sheet switch, it is not necessary to separately prepare an adhesive, and a process of applying the adhesive is not required. .

  Another characteristic configuration of the sheet switch according to the present invention is that the light reflecting portion is formed by attaching an adhesive to the surface of the reflecting agent.

  According to the above characteristic configuration, since the sheet switch is assembled after the adhesive is attached to the surface of the reflective agent, the reflective agent need not be special, and various types of reflective agents can be used. .

  Another characteristic configuration of the sheet switch according to the present invention is that the reflective agent includes a white pigment.

  According to the above characteristic configuration, since the white pigment having high reflectance is used, the sheet switch can emit light strongly.

  Another characteristic configuration of the sheet switch according to the present invention is that the thickness of the light reflecting portion is 10 μm to 20 μm.

  According to the above characteristic configuration, the thickness of the sheet switch can be reduced as compared with the case where an adhesive sheet is used for bonding.

Hereinafter, a seat switch according to the present invention will be described with reference to the drawings.
FIG. 1A is a cross-sectional view of a seat switch 10 according to the present invention, and FIG. 1B is a cross-sectional view illustrating a state in which a pressing force is applied from above the seat switch 10.
As shown in FIG. 1, the sheet switch 10 is configured by mounting various components on a substrate 1 on which a fixed contact 2 and a circuit pattern 3 are provided. Specifically, a dome-shaped movable contact member 4 provided in contact with the circuit pattern 3 is disposed so as to cover the upper side of the fixed contact 2. A light guide sheet 5 is provided on the substrate 1 in a state where the movable contact member 4 is provided so as to cover the substrate 1 and the movable contact member 4. Further, above the movable contact member 4, a plurality of light reflecting portions 7 that reflect light guided to the light guide sheet 5 are partially provided on a surface of the light guide sheet 5 facing the movable contact member 4. Is provided.

  The movable contact member 4 is formed of an elastically deformable metal or conductive film member. Specifically, the movable contact member 4 is a dome-shaped member having a circular periphery, and the peripheral portion is fixed in a state of being electrically connected to the circuit pattern 3. Further, the dome-shaped top of the movable contact member 4 is arranged to be directly above the fixed contact 2. Therefore, when a pressing force is applied to the movable contact member 4 from above, the movable contact member 4 is deformed so as to be crushed as shown in FIG. . When the pressing force disappears, the movable contact member 4 is restored to the original position and separated from the fixed contact 2.

  The light guide sheet 5 is made of a transparent sheet-like member that can transmit light with high transmittance and can be deformed. A light emitting element 6 configured using a light emitting diode or the like is provided at an arbitrary position on the substrate 1, and light emitted from the light emitting element 6 is guided into the light guide sheet 5. The light guided to the inside of the light guide sheet 5 is theoretically propagated without leaking to the outside of the light guide sheet 5 as long as it is totally reflected on both the front and back surfaces of the light guide sheet 5.

  Each light reflecting portion 7 is a bulk-like member formed including a material having a high reflectance, and is bonded to the light guide sheet 5. Therefore, in the portion where the light reflecting portion 7 is bonded to the light guide sheet 5, total reflection of light propagating through the light guide sheet 5 does not occur, and light leaks from the light guide sheet 5 to the light reflecting portion 7. As a result, as indicated by broken line arrows in the figure, the light leaking from the light guide sheet 5 is reflected on the surface of the light reflecting portion 7 and is observed from the outside of the sheet switch 10. That is, the sheet switch 10 having an illumination function is obtained. For example, each light reflecting portion 7 is formed in a bulk shape by kneading an adhesive into a reflective agent containing a white pigment having a high reflectance. As described above, since the adhesive is kneaded into the light reflecting portion 7, the light reflecting portion 7 adheres well to both the light guide sheet 5 and the movable contact member 4. Various types of adhesives such as acrylic, silicone, urethane, and natural rubber can be used.

  In addition, each light reflecting portion 7 has a predetermined thickness and is provided between the light guide sheet 5 and the movable contact member 4, and thereby, between the light guide sheet 5 and the movable contact member 4. A space S is partially formed. In the present embodiment, the thickness d of the light reflecting portion 7 is 10 μm to 20 μm.

  As shown in FIG. 1B, when a pressing force from above is applied to the central portion C of the sheet switch 10, the movable contact member 4 comes into contact with the fixed contact 2 on the substrate 1, and the fixed contact 2 and The circuit pattern 3 is electrically connected via the movable contact member 4. In this state, since the light guide sheet 5 and the movable contact member 4 are integrally pushed down, the light guide sheet 5 and the movable contact member 4 are in contact with each other at the peripheral portion P of the sheet switch 10. Thus, when the light guide sheet 5 and the movable contact member 4 come into contact with each other, the light guide sheet 5 at the contact portion does not cause total reflection of light propagating through the inside, and is movable from the light guide sheet 5. Light goes out toward the contact member 4, and light reflection occurs on the surface of the movable contact member 4. That is, when a pressing force from above is applied to the sheet switch 10, reflected light from the peripheral portion P in addition to the central portion C may be newly seen from the outside of the sheet switch 10.

  However, in the sheet switch 10 according to the present invention, the movable contact member 4 that comes into contact with the light guide sheet 5 when a pressing force is applied from above is a material having a low reflectance. Therefore, even if the light guide sheet 5 and the movable contact member 4 are in contact with each other, strong reflected light from the contact portion is not seen. Thus, conventionally, since the white adhesive sheet having a high reflectivity as shown in FIG. 4 is in contact with the light guide sheet 5, the portion where the light guide sheet 5 and the adhesive sheet are in close contact with each other, Although there has been a problem that a large unevenness in the degree of light reflection occurs between the parts that are not in close contact with each other, such a problem does not occur in the sheet switch 10 according to the present invention.

FIG. 2 is a diagram illustrating an arrangement state of the plurality of light reflecting portions 7 on the light guide sheet 5. As shown in FIG. 2, the plurality of light reflecting portions 7 are collectively provided in the central portion C of the sheet switch 10. The interval between the plurality of light reflecting portions 7: m is about 0.5 mm. The diameter: φ of the light reflecting portion 7 at the portion in contact with the light guide sheet 5 is about 0.3 mm. The amount of light reflected by the light reflecting portion 7 is proportional to the diameter of the light reflecting portion 7 in contact with the light guide sheet 5, so that the diameter of the light reflecting portion 7 is increased in order to increase the amount of reflected light. do it. Further, in order to adjust the total amount of light reflected by the plurality of light reflecting portions 7, the number of the light reflecting portions 7 may be changed.
Therefore, for example, when the sheet switch 10 is desired to be brightly illuminated, at least one of increasing the diameter: φ of each light reflecting portion 7 and increasing the number of light reflecting portions 7 may be performed.

<Another embodiment>
<1>
In the above embodiment, an example in which the light reflecting portion 7 is formed by kneading an adhesive into a reflective agent containing a white pigment has been described. However, the configuration of the light reflecting portion 7 may be modified. For example, the light reflecting portion 7 is formed by adhering to the surface of the reflecting agent containing a white pigment by printing or applying an adhesive or the like, so that the light reflecting portion 7 becomes the light guide sheet 5 and the movable contact member 4. It can be configured to adhere well to both.
Further, the reflective agent is not limited to a white pigment, and can be appropriately changed as long as the material has a high reflectance.
Furthermore, in the said embodiment, although the thickness of the light reflection part 7: d, the space | interval between several light reflection parts 7: m, and the diameter of the light reflection part 7: The value of φ was illustrated, those numerical values are It can be changed as appropriate.

<2>
When manufacturing a sheet switch module including a plurality of the above-described sheet switches, the light reflecting portion may be provided in a portion other than the sheet switch. FIG. 3 is a top view of the sheet switch module 100 including a plurality of sheet switches. In the sheet switch module 100, the two light emitting elements 6 are configured to emit light toward a plurality of arranged sheet switches 10. That is, the light emitting element 6 is shared by a plurality of sheet switches 10. Therefore, in each sheet switch 10, the light emitted from the light emitting element 6 is reflected by each light reflecting portion 7 as described in the above embodiment. Also in the sheet switch module 100, the light guide sheet 5 and the movable contact member (not shown) below the light guide sheet 5 are bonded by the bonding function of the light reflecting portion 7 as in the above embodiment.

  Further, in the sheet switch module 100 described here, a plurality of the light reflecting portions 7 are also provided in the gap portion Y between the outer end X of the sheet switch module 100 and the plurality of sheet switches 10. Therefore, also in the outer end X and the gap Y of the sheet switch module 100, the light guide sheet 5 and the substrate (not shown) below the light guide sheet 5 are bonded by the bonding function of the light reflecting section 7. The sheet switch module 100 is mounted on an electric device such as a cellular phone and used for a push button switch portion of the electric device. The outer end X and the gap Y are formed by a housing of the electric device. It is the part that is obscured. Therefore, even if the light propagating inside the light guide sheet 5 is reflected by the light reflecting portion 7 provided at the outer end X and the gap portion Y, the reflected light is not seen outside the electric device. .

  As described above, the light guide sheet 5 and the lower substrate and the movable contact member are bonded to each other at a plurality of positions in a wide range of the sheet switch module 100, so that the light guide sheet 5 and the lower substrate are provided. In addition, adhesion to the movable contact member becomes strong.

  INDUSTRIAL APPLICABILITY The present invention can be used for a sheet switch that provides a lighting function to a push button switch provided in an electric device such as a mobile phone.

Cross section of sheet switch The figure explaining the arrangement state of a plurality of light reflection parts to a light guide sheet Top view of the seat switch module Sectional view of a conventional sheet switch

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Fixed contact 4 Movable contact member 5 Light guide sheet 6 Light emitting element 7 Light reflection part 10 Sheet switch S Space

Claims (5)

  1. A substrate provided with fixed contacts;
    A dome-shaped movable contact member which is arranged so as to cover the upper side of the fixed contact and is configured to contact the fixed contact under a pressing force from above;
    A light emitting device provided on the substrate;
    A light guide sheet that is provided so as to cover the upper side of the movable contact member and guides light emitted from the light emitting element;
    The light guide sheet has a predetermined thickness and is provided between the light guide sheet and the movable contact member to partially form a space between the light guide sheet and the movable contact member. A sheet switch comprising a plurality of light reflecting portions for reflecting light guided to the surface.
  2.   The sheet switch according to claim 1, wherein the light reflecting portion is formed by kneading an adhesive into a reflecting agent.
  3.   The sheet switch according to claim 1, wherein the light reflecting portion is formed by attaching an adhesive to a surface of a reflecting agent.
  4.   The sheet switch according to claim 2, wherein the reflective agent includes a white pigment.
  5.   The thickness of the said light reflection part is 10 micrometers-20 micrometers, The sheet switch as described in any one of Claims 1-4.
JP2007324813A 2007-12-17 2007-12-17 Sheet switch Pending JP2009146815A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2007324813A JP2009146815A (en) 2007-12-17 2007-12-17 Sheet switch

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2007324813A JP2009146815A (en) 2007-12-17 2007-12-17 Sheet switch

Publications (1)

Publication Number Publication Date
JP2009146815A true JP2009146815A (en) 2009-07-02

Family

ID=40917173

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2007324813A Pending JP2009146815A (en) 2007-12-17 2007-12-17 Sheet switch

Country Status (1)

Country Link
JP (1) JP2009146815A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2355118A1 (en) * 2010-01-29 2011-08-10 Research In Motion Limited Dome overlay assembly for a keyboard and method of constructing a dome overlay structure for a mobile device keyboard
US8258418B2 (en) 2010-01-29 2012-09-04 Research In Motion Limited Keyboard dome overlay structure
CN108335935A (en) * 2018-03-29 2018-07-27 联想(北京)有限公司 Back lighting device, keyboard and electronic equipment

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2355118A1 (en) * 2010-01-29 2011-08-10 Research In Motion Limited Dome overlay assembly for a keyboard and method of constructing a dome overlay structure for a mobile device keyboard
US8258418B2 (en) 2010-01-29 2012-09-04 Research In Motion Limited Keyboard dome overlay structure
CN108335935A (en) * 2018-03-29 2018-07-27 联想(北京)有限公司 Back lighting device, keyboard and electronic equipment

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