JP2016081651A - Key switch structure and portable terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a key switch structure which achieves water cut-off performance and is simple and small.SOLUTION: A key switch structure includes: a housing; a substrate disposed within the housing; a key switch circuit pattern directly formed at the housing and configured to contact with a circuit formed on the substrate; a dome switch disposed on the key switch circuit pattern; a water cut-off sheet covering the dome switch; and a key top partially exposed to the outside of the housing and configured to press the dome switch. The structure provides a key switch structure which achieves water cut-off performance and is simple and small.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a key switch structure and a portable terminal device.

  Conventionally, a so-called side key is known which is disposed on a side surface of a casing of a mobile phone or the like. In such a side key, the key top is exposed on the outside of the housing, and by operating the exposed portion, the circuit provided on the substrate disposed inside the housing is connected or disconnected. It can be done. In this way, various proposals that can intermittently connect a circuit arranged inside the housing are also known (see, for example, Patent Document 1).

Japanese Utility Model Publication No. 63-18728

By the way, the side key in a portable terminal device such as a cellular phone is required to be water-tight. The proposal disclosed in Patent Document 1 is provided with water-stopping properties, but due to its structure, it is difficult to adopt it for a recent thinned mobile terminal device. Conventionally, in addition to Patent Document 1, there is known a structure in which a dome switch is provided on a substrate disposed in a casing, and this dome switch is pressed by operating a key top (button component). However, in the conventional structure, another member must be interposed between the dome switch and the key top, and a water-stop structure that ensures water-stop between the other member and the housing must be constructed. There was a problem that the number of parts increased and the structure increased in size.

  In one aspect, an object of the key switch structure and the portable terminal device disclosed in the present specification is to provide a simple and small key switch structure having water-stopping properties.

  The key switch structure disclosed in this specification includes a case, a substrate disposed in the case, a key switch circuit pattern formed directly on the case and in contact with a circuit formed on the substrate. A dome switch disposed on the key switch circuit pattern, a waterproof sheet that covers the dome switch, a key top that is partially exposed to the outside of the housing and that depresses the dome switch. Prepare.

Further, the mobile terminal device disclosed in the present specification is a mobile terminal device in which a substrate is disposed inside a housing, and is directly formed on the housing and is brought into contact with a circuit formed on the substrate. A key switch circuit pattern, a dome switch disposed on the key switch circuit pattern, a water-stop sheet covering the dome switch,
A key switch structure having a part exposed to the outside of the housing and a key top for pressing down the dome switch.

  According to the key switch structure and the portable terminal device disclosed in this specification, a simple and small key switch structure having water-stopping property can be provided.

FIG. 1 is a perspective view of a portable terminal device according to an embodiment. 2 is a cross-sectional view of the portable terminal device according to the embodiment, taken along line AA in FIG. FIG. 3A is a plan view of a power button provided in the mobile terminal device of the embodiment, and FIG. 3B is a front view of the power button provided in the mobile terminal device of the embodiment. 4A is an explanatory view of the key switch structure with the power button removed, viewed from the X direction in FIG. 2, and FIG. 4B is a cross-sectional view taken along the line BB in FIG. 4A. . FIG. 5 is an explanatory diagram showing a conduction state of the key switch structure of the embodiment. FIG. 6A is a plan view of a volume button provided in the portable terminal device of the embodiment, and FIG. 6B is a front view of the volume button provided in the portable terminal device of the embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, in the drawings, the dimensions, ratios, and the like of each part may not be shown so as to completely match the actual ones. Further, depending on the drawings, components that are actually present may be omitted for convenience of explanation, or dimensions may be exaggerated from the actual drawing.

(Embodiment)
The mobile terminal device 1 of the embodiment will be described with reference to FIGS. 1 to 6. FIG. 1 is a perspective view of a portable terminal device 1 according to the embodiment. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1 of the mobile terminal device 1 according to the embodiment. 3A is a plan view of the power button 21 provided in the mobile terminal device 1 of the embodiment, and FIG. 3B is a front view of the power button 21 provided in the mobile terminal device 1 of the embodiment. 4A is an explanatory view of the key switch structure 20 with the power button 21 removed, as viewed from the X direction in FIG. 2, and FIG. 4B is a cross-sectional view taken along line BB in FIG. 4A. It is. FIG. 5 is an explanatory diagram showing a conduction state of the key switch structure of the embodiment. 6A is a plan view of the volume button 31 provided in the mobile terminal device 1 of the embodiment, and FIG. 6B is a front view of the volume button 31 provided in the mobile terminal device 1 of the embodiment.

  The mobile terminal device 1 has a housing in which a front case 3 and a rear case 4 are combined. Referring to FIG. 2, in the mobile terminal device 1 of the present embodiment, a substrate 5 is disposed in a rear case 4 formed in a concave shape. A battery held in a battery holder 7 is built in the rear case 4. And the front case 3 with which the screen part 6 was assembled | attached is formed, and the external shape of the portable terminal device 1 is formed. In the mobile terminal device of the present embodiment, the front case 3 is fitted inside the rear case 4, but the assembled form of the rear case 4 and the front case 3 is not limited to this. In addition, a seal member 9 is provided around the front case 3 to ensure water-stopping between the front case 3 and the rear case 4.

  The mobile terminal device 1 in this embodiment includes a key switch structure 20 and a key switch structure 30. The key switch structure 20 and the key switch structure 30 form a side key provided on the side surface of the casing included in the mobile terminal device 1. The mobile terminal device 1 in the present embodiment is a mobile phone, which is a so-called smartphone, but has a key switch structure similar to that of the present embodiment as a side key of another mobile terminal device, for example, a tablet-type information processing device. It can also be adopted.

  The key switch structure 20 included in the mobile terminal device 1 relates to the power button 21, and the key switch structure 30 relates to the volume button 31. The power button 21 and the volume button 31 are examples of key tops, and the key switch structure is not limited to these switches. Referring to FIGS. 3A and 3B, a contact portion 21a formed in a concave shape is provided in the central portion, and a flange portion 21b is provided on each side portion. The top part of the dome switch 22 which will be described in detail later is located at the contact part 21a. The power button 21 is disposed such that a part thereof, specifically, the side opposite to the side where the contact portion 21 a is provided is exposed from the insertion hole 4 a provided in the rear case 4. Specifically, the power button 21 is disposed between the front case 3 and the rear case 4 in a state of being biased to the outside of the rear case 4 by the elasticity of the dome switch 22 described in detail later. At this time, since the collar portion is engaged with the periphery of the insertion hole 4a, the power button 21 does not fall out of the insertion hole 4a. Since the key switch structure 20 and the key switch structure 20 have the same basic configuration, the configuration of the key switch structure 20 will be mainly described below. In addition, the functions assigned to the key switch structure may be assigned not only to turning on / off the power supply and increasing / decreasing the volume, but also to other functions.

  Referring to FIGS. 2, 4A, 4B, and 5, the front case 3 has a first through hole 3a and a second through hole 3b. An internal pattern 24 is formed around the first through hole 3a. An outer peripheral pattern 25 is formed around the second through hole 3b. Both the internal pattern 24 and the outer peripheral pattern 25 are directly formed on the front case 3 forming a part of the housing. Both the internal pattern 24 and the outer peripheral pattern 25 are provided so as to be in contact with a circuit formed on the substrate 5.

  The first through hole 3a communicates the inside and outside of the housing, more specifically, the inside and outside of the front case 3. The internal pattern 24 formed around the first through hole 3a is gold plating formed by LDS (Laser Direct Structure) processing. That is, the internal pattern 24 is formed by applying gold plating directly to the surface of the front case 3 by LDS. Similarly, the second through hole 3b also communicates the inside and outside of the housing, more specifically, the inside and outside of the front case 3. The internal pattern 24 formed around the second through hole 3a is gold plating formed by LDS (Laser Direct Structure) processing. That is, the internal pattern 24 is formed by applying gold plating directly to the surface of the front case 3 by LDS.

  The outer peripheral pattern 25 is provided around the inner pattern 24 at a distance from the inner pattern 24. That is, the outer peripheral pattern 25 and the internal pattern 24 are in an insulated state. The internal pattern 24 is a portion where the central portion of the dome switch 22 comes into contact with or separates from the dome switch 22 described later. On the other hand, the outer peripheral pattern 25 is a portion where the outer peripheral portion of the dome switch 22 is grounded. As shown in FIG. 5, the internal pattern 24 and the outer peripheral pattern 25 having such a relationship become conductive when the dome switch 22 is pressed and the center of the dome switch 22 contacts the internal pattern 24.

  The key switch structure 20 of this embodiment includes a dome switch 22 disposed on a key switch circuit pattern including an internal pattern 24 and an outer peripheral pattern 25. The dome switch 22 is made of metal, is formed in a dome shape, and has elasticity. When the top of the dome switch 22 is pressed down, the top is recessed and comes into contact with the internal pattern 24. When the top is released, the elasticity returns to its original shape and the contact with the internal pattern 24 is released. The outer periphery of the dome switch 22 is always in contact with the outer peripheral pattern 25. A first through hole 3 a is opened inside the dome switch 22, more specifically, inside the convex shape of the dome switch 22. When the dome switch 22 is pressed, the internal volume is reduced. At that time, if a structure for discharging the internal air is provided, the dome switch 22 can be pressed smoothly, and a stable operational feeling can be obtained. That is, the first through hole 3a functions as an air escape when the dome switch 22 is pressed. In the present embodiment, the second through hole 3b is not opened in the dome switch 22, but the second through hole 3b may be opened in the dome switch 22.

  The key switch structure 20 includes a water stop sheet 26 that covers the dome switch 22. The water-stop sheet 26 of the present embodiment is a water-stop tape having one surface as an adhesive surface. The water-stop sheet 26 extends to the outside from the outer peripheral portion of the dome switch 22, thereby performing a water-stop function around the key switch structure 20.

  A cushioning material 23 made of silicon is disposed between the dome switch 22 and the water stop sheet 26. The abutting portion 21 a of the power button 21 abuts against the cushioning material 23 via the water stop sheet 26. Thereby, the operational feeling of the power button 21 is improved.

  When such a key switch structure 20 is operated, that is, when the power button 21 is pressed, the top of the dome switch 22 contacts the internal pattern 24 as shown in FIG. 5, and the internal pattern 24 and the outer peripheral pattern 25 are in a conductive state. It becomes. As a result, a signal relating to the on / off of the power supply is issued to the circuit formed on the substrate 5.

  In the case of the key switch structure 30, the volume is increased or decreased by operating the volume button 31. Here, as shown in FIGS. 6A and 6B, the volume button 31 is provided with two contact portions 31a on the side located inside the housing. Each of the contact portions 31a is a portion corresponding to the contact portion 21a of the power button 21, and the top portion of the dome switch for increasing or decreasing the volume is disposed in this portion. The volume button 31 is provided with a flange 31 b like the power button 21 and is mounted between the front case 3 and the rear case 4 in the same manner as the power button 21.

  As described above, the key switch structure 20 and the key switch structure 30 included in the mobile terminal device 1 of the present embodiment are both constructed with a simple and small key switch structure having water-stopping properties with a small number of parts. Yes.

  Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited to the specific embodiment, and various modifications, within the scope of the gist of the present invention described in the claims, It can be changed.

DESCRIPTION OF SYMBOLS 1 Portable terminal device 3 Front case 3a 1st through hole 3b 2nd through hole 4 Rear case 5 Board | substrate 9 Seal member 20, 30 Key switch structure 21 Power button (key top)
21a Abutting part 21b collar part 22 dome switch 23 cushioning material 24 internal pattern 25 outer peripheral pattern 26 waterproof sheet 31 volume button (key top)
31a contact part 31b collar part X arrow

Claims (5)

A housing,
A substrate disposed in the housing;
The key switch circuit pattern is formed directly on the housing and brought into contact with the circuit formed on the substrate.
A dome switch disposed on the key switch circuit pattern;
A waterproof sheet covering the dome switch;
A portion of the key top that is exposed to the outside of the housing and depresses the dome switch;
Key switch structure with   2. The key switch circuit pattern according to claim 1, wherein the key switch circuit pattern includes an internal pattern in which a central portion of the dome switch is separated from and operated by the operation of the dome switch and an external pattern in contact with an outer peripheral portion of the dome switch. Key switch structure.   3. The key switch structure according to claim 1, wherein the key switch circuit pattern is provided in a through hole that communicates with the inside and outside of the housing and opens in the dome switch.   The key switch structure as described in any one of Claims 1 thru | or 3 with which the shock absorbing material was arrange | positioned between the said dome switch and the said water stop sheet | seat. A mobile terminal device in which a substrate is arranged inside a housing,
A key switch circuit pattern formed directly on the housing and in contact with a circuit formed on the substrate;
A dome switch disposed on the key switch circuit pattern;
A waterproof sheet covering the dome switch;
A portable terminal device having a key switch structure including a key top part of which is exposed to the outside of the housing and depresses the dome switch.

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