KR20040044750A - Dome switch for mobile phone - Google Patents

Abstract

PURPOSE: A dome switch of a cellular phone is provided to form plural projections on an inner side of the dome switch, and to make deep grooves toward projection head portions of the projections from projection bottom portions of the projections, thereby contacting the dome switch with a contact terminal of a PCB by a small operating force of a keypad. CONSTITUTION: Plural projections(210) have deep grooves formed toward head portions of the projections(210) from bottom portions of the projections(210). When a keypad(100) is operated, an outer portion of a dome switch(200) has a reduced contact surface contacted with the keypad(100). In case a peripheral portion of the dome switch(200) is pressed by the keypad(100), an elastic transformation amount of the peripheral portion gets bigger. The dome switch(200) is contacted with a contact terminal(310) of a PCB(300) by elastically transforming a central portion and the peripheral portion of the dome switch(200).

Description

Dome switch of mobile phone {DOME SWITCH FOR MOBILE PHONE}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a metal dome switch applied to a key input device of a communication device such as a mobile phone, and more particularly, to the dust or contact of the contact part of the dome switch. The present invention relates to a dome switch that prevents a poor contact due to light or is easy to operate.

In general, a communication device such as a mobile phone is configured with a key input device for inputting information and operating a device, and the key input device turns on / off contacts of a circuit on a circuit board according to a trend of light weight, miniaturization, and thickness of the communication device. A structure has been developed for placing a metal dome switch to be turned off and mounting a keypad on the dome switch.

As an example of the conventional key input device, an elliptical dome switch 2 made of a conductive metal is formed at a lower portion of the keypad 1 made of rubber (rubber) or the like as shown in FIGS. Under the dome switch, a circuit board 3 constituting a circuit of a communication device such as a mobile phone is formed.

An end of the dome switch 2 is connected to a circuit portion (not shown) of the circuit board 2, and a dome switch is pushed as the keypad 2 is pushed as shown in FIG. 2. The center portion of the circuit board 2 is lowered to be in contact with a contact terminal (not shown) of the circuit board 2 so as to function as a key switch.

However, since the dome switch configured as described above is composed of a smooth curved surface at the center portion of the circuit board contact terminal, when the foreign matter 4 such as dust is attached to the contact portion as shown in FIG. There is a disadvantage that a defect occurs.

In addition, the dome switch configured as described above has a drawback in that the inner and outer surfaces of the dome switch have a continuous curved shape, so that the center portion thereof is elastically deformed to the position where the circuit board is mounted.

In addition, the dome switch configured as described above has a continuous curved surface inside and outside of the dome switch, and thus the peripheral portion of the dome switch is not easily elastically deformed to the position where the circuit board is mounted, so that the contact terminal of the circuit board is not shown. By forming a wide, the central portion is plastically deformed, if there is a poor contact, there is a disadvantage that it is difficult to contact the contact by pressing the peripheral portion.

The present invention to solve the above problems of the prior art, by providing a plurality of projections on the inner surface of the dome switch, to provide a dome switch to disperse the risk due to foreign matter stacked.

The present invention, in order to solve the above problems of the prior art, by forming a plurality of projections on the inner surface of the dome switch and forming a deep groove toward the projection head from the bottom of the projection, the dome switch by the small operating force of the keypad An object of the present invention is to provide a dome switch in contact with a contact terminal of a circuit board.

1 is a schematic cross-sectional view of a keypad and a dome switch according to the prior art.

Figure 2 is an operation of the keypad and the dome switch according to the prior art.

Figure 3 is a state diagram of poor contact of the dome switch in Figure 2;

4 is a cross-sectional view of one embodiment according to the present invention.

Figure 5 is an operation of one embodiment according to the present invention.

Explanation of symbols on the main parts of the drawings

100: key pad

200: dome switch 210: protrusion

300: circuit board 310: contact terminal

The present invention provides a dome switch of a mobile phone contacting a contact terminal of a circuit board by operation of a keypad, wherein a plurality of protrusions contacting the contact terminal are formed on an inner surface of the dome switch. It is about.

In another aspect, the present invention relates to a dome switch of a mobile phone, wherein the protrusion is hollow by forming a deep groove from the bottom of the protrusion toward the head of the protrusion. It is also.

The present invention also relates to a dome switch of a mobile phone, wherein the head of the projection has a spherical shape.

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the drawings. Figure 4 shows a cross-sectional view of one embodiment according to the present invention, Figure 5 shows an operation of one embodiment according to the present invention.

Referring to Figure 4, one embodiment according to the present invention has a projection (210). A plurality of protrusions 210 are adjacent to and protruded from the inner surface of the dome switch 200.

Referring to FIG. 4, the plurality of protrusions 210 form a hollow shape by forming a deep groove toward the head of the protrusion 210 from the bottom of the protrusion 210. Therefore, the outer side of the dome switch 200 in contact with the keypad 100 is reduced in contact area when in contact with the keypad 100. On the other hand, the head of the protrusion 210 is formed in a spherical shape so that the contact with the contact terminal 310 of the circuit board 300 is easily made.

Hereinafter, the operation of the above-described embodiment will be described.

Referring to FIG. 4, since the plurality of protrusions 210 are formed with deep grooves from the bottom of the protrusion 210 toward the head of the protrusion 210, an outer portion of the dome switch 200 when the keypad 100 is operated. The contact area in contact with the keypad 100 is reduced. Accordingly, when the keypad 100 is pressed with the same force, the inner surface of the dome switch has a larger elastic deformation amount than in the conventional art, so that the contact terminal 310 of the circuit board 300 is easily contacted.

Meanwhile, referring to FIG. 5, a plurality of protrusions 210 have deep grooves formed from the bottom of the protrusion 210 toward the head of the protrusion 210 so that the outer portion of the dome switch 200 when the keypad 100 is operated. The contact area in contact with the keypad 100 is reduced, and thus, even when the keypad 100 is pressed at an angle, the peripheral part of the dome switch 200 is pressed even when the keypad 100 is pressed against the periphery of the dome switch 200. Since the elastic deformation amount is larger than that of the related art, contact between the peripheral portion of the dome switch 200 and the contact terminal 310 of the circuit board 300 is easily performed.

In addition, as described above, according to the present invention, the dome switch 200 may be brought into contact with the contact terminal 310 of the circuit board 300 by elastically deforming the central and peripheral portions of the dome switch 200. The foreign matter may be stacked to disperse the risk of poor contact with the contact terminal 310 of the circuit board 300.

In the above-described embodiment, the plurality of protrusions may have a hollow shape in which grooves are formed from the bottom of the protrusion toward the head. However, in another embodiment, the plurality of protrusions may not be hollow. .

In the above embodiment, the heads of the plurality of protrusions are spherical in shape, but in other embodiments, the heads of the plurality of protrusions may be in other shapes such as flat.

The dome switch according to the present invention has an advantage of dispersing the risk due to foreign matter stacking by forming a plurality of protrusions on the inner surface of the dome switch.

In addition, the dome switch according to the present invention forms a plurality of protrusions on the inner surface of the dome switch and forms a deep groove from the bottom of the protrusion toward the protrusion head, so that the dome switch is connected to the contact terminal of the circuit board even by the small operating force of the keypad. There is also an advantage in contact with.

In addition, the dome switch according to the present invention forms a plurality of protrusions on the inner surface of the dome switch and toward the protrusion head from the bottom of the protrusion By forming the deep grooves, even when the keypad is obliquely pressed to press the peripheral portion of the dome switch, the elastic deformation of the peripheral portion of the dome switch is larger than that of the prior art, so that the peripheral portion of the dome switch is brought into contact with the contact terminal of the circuit board. There is also an advantage that is easily made.

Claims (3)

In the dome switch of a mobile phone contacting the contact terminal of the circuit board by the operation of the keypad, The dome switch of the mobile phone, characterized in that a plurality of projections are formed on the inner surface of the dome switch in contact with the contact terminal. The method of claim 1, The projection is a dome switch of the mobile phone, characterized in that the hollow (hollow) form by forming a deep groove toward the head of the projection from the bottom of the projection. The method of claim 2, Dome switch of the mobile phone, characterized in that the head portion of the protrusion has a spherical shape.