JP2006210174A - Operation key unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent warpage of a circuit board, damage in electronic parts and peeling off of the electronic parts from the circuit boards caused by depressing operations of the operation keys. <P>SOLUTION: An operation key unit 31 is provided with an operation key 4 that is energized outward from inside of a cabinet 2, and a switching pattern 11b formed on a surface 11a of the circuit board 11 arranged inside the cabinet 2 opposing to the operation key 4, while the operation key 4 is equipped with a key body 15 that is exposed outward from the cabinet 2, a conductive part 23 that has conductivity and is deployed in the opposing face 15b side of the key body 15 opposing to the switching pattern 11b, and that is conducted with the switching pattern 11b to let the switching pattern 11b be conductive when the key body 15 is depressed toward inside of the cabinet 2, and an elastic body 17 that is elastically deformable and arranged between the key body 15 and the conductive part 23. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to various electronic devices such as a mobile phone, a simple mobile phone (PHS (registered trademark)), a PDA (Personal Digital Assistants), a digital camera, a digital video camera, a personal computer, etc., a fan, a dryer, an electric toothbrush, etc. The present invention relates to an operation key unit used for electrical equipment.

  Conventionally, various electronic devices such as mobile phones, simple mobile phones, PDAs, digital cameras, digital video cameras, and personal computers, and electric devices such as electric fans, dryers, and electric toothbrushes are provided from the outside to the inside. An operation key unit that is pressed down is widely used (see, for example, Patent Document 1). This type of operation key unit includes an operation key that can be pressed from the outside to the inside of the housing, a switch pattern formed on the surface of the circuit board facing the operation key, and a click dome that covers the switch pattern. And has.

In this operation key unit, when the operation key exposed outward is pressed toward the circuit board, the click dome (made of a metal material) protruding from the circuit board is elastically deformed, so that the switch pattern of the circuit board is changed. It is configured to conduct.
Further, for example, as shown in FIG. 6, a projection 57 that protrudes toward the click dome 55 is provided at the tip of the main body 53 of the operation key 51, and the pressure for pressing the operation key 51 is concentrated on a part of the click dome 55. As described above, there is also an operation key unit having a configuration in which the click dome 55 is elastically deformed by the projection 57. In the case of this configuration, even if the operation key 51 is pressed with a small force, the force that presses the click dome 55 concentrates on the tip of the projection 57, so that the click dome 55 is easily and reliably elastically deformed. Thus, the switch pattern 61 of the circuit board 59 can be made conductive.
JP-A-7-58815

However, in the conventional operation key unit, although the click dome 55 can be pressed with a small force, the pressure for pressing the operation key 51 is concentrated on a part of the circuit board 59 via the protrusion 57 and the click dome 55. There is a problem that the circuit board 59 is bent, an electronic component mounted on the circuit board 59 is damaged, or an electronic component mounted on the circuit board 59 is peeled off from the circuit board 59 due to the bending of the circuit board 59. In addition, since the click dome 55 is attached to the circuit board 59, if the contact state between the click dome 55 or the click dome 55 and the switch pattern 61 is defective, it is necessary to repair the circuit on the circuit board 59. There is also a problem that the repair work becomes troublesome.
The present invention has been made in view of the above-described circumstances, and when the operation key is pressed, the switch pattern is reliably turned on, and the circuit board is warped, the electronic component is damaged, and the operation key is pressed. An object of the present invention is to provide an operation key unit that can prevent peeling of electronic components from a circuit board, and to provide an operation key unit that can be easily repaired.

In order to solve the above problems, the present invention proposes the following means.
An operation key unit according to the present invention is formed on the surface of an operation key that is urged outward from the inside of the housing and a circuit board that is disposed inside the housing so as to face the operation key. A switch body, and the operation key is disposed on the key body exposed to the outside of the housing, and on the opposing surface side of the key body having conductivity and facing the switch pattern, the key body A conductive part that contacts the switch pattern when the switch is pushed down toward the inside of the housing and makes the switch pattern conductive, and an elastically deformable elastic body that is disposed between the key body and the conductive part It is characterized by providing.
In the operation key unit according to the present invention, the elastic body is formed by forming a thin metal plate into a substantially convex shape that protrudes from the opposing surface of the key body toward the conducting portion.

Furthermore, in the operation key unit according to the present invention, the elastic body has a front end wall portion having a flat surface to which the conducting portion is attached, and a side wall portion extending from the opposing surface of the key body toward the periphery of the front end wall portion. And a curved wall portion having a convex curved surface formed between the side wall portion and the tip wall portion.
In the operation key unit according to the present invention, the operation key includes a support portion that extends from the facing surface of the key body toward the circuit board, and the tip of the support portion is the tip of the conduction portion from the facing surface. It is characterized by being located closer to the key body than the position.

According to the present invention, when the key body is pushed down from the outer side of the housing to the inside, and when the key body is further pushed down from a state where the conduction part is in contact with the switch pattern, the key body is interposed between the key body and the conduction part. Since the arranged elastic body absorbs the force that elastically deforms and pushes down the key body, it is possible to suppress the circuit board from being pressed by an excessive force. Therefore, it is possible to prevent the circuit board from warping due to the force of pressing the circuit board by the key body, damage to the electronic component mounted on the circuit board, and peeling of the electronic component from the circuit board.
In addition, when a defect occurs in the elastic body or the conductive portion, only the operation key needs to be replaced, so that the operation key unit can be repaired easily.

1 to 5 show one embodiment according to the present invention, and the embodiment described here is a case where the present invention is applied to a mobile phone. As shown in FIG. 1, a mobile phone 1 according to this embodiment includes a housing 2 formed in a substantially rectangular plate shape in plan view, and a plurality of operation keys 4 such as numeric keys, a call key, and an end key. And a display unit 5 for displaying various kinds of information, a microphone unit for a call, and a speaker unit (not shown). The operation keys 4 of the operation unit 3 and the display surface of the display unit 5 are exposed outward from one main surface 2 a of the housing 2.
The microphone part and the speaker part are respectively arranged at both ends 2b and 2c in the longitudinal direction of the casing 2 in the casing 2, and the speaker part is a sound emitting port formed at one end of the main surface 2a. Sounds and the like are emitted through 7a. The microphone unit collects sound and the like through a sound collection port 7 b formed at the other end of the main surface 2 a of the housing 2. Note that an antenna 9 for performing wireless communication with the base station is provided at one end 2b in the longitudinal direction of the housing 2 provided with the speaker unit.

  As shown in FIG. 2, a circuit board 11 that electrically connects the display unit 5, the antenna 9, the microphone unit, the speaker unit, and the like is disposed inside the housing 2. On the surface 11 a of the circuit board 11, electronic components (not shown) for controlling various functions such as a call function, a display function, and an input operation function of the mobile phone 1 are mounted. Two electrode portions (switch patterns) 11b for contacting the conductive portion are formed. A substantially sheet-like rubber sheet 13 that is elastically deformable is disposed on the surface 11 a of the circuit board 11. The rubber sheet 13 is provided with an operation key 4 disposed to face the electrode portion 11 b of the circuit board 11.

The operation key 4 includes a key main body 15 formed integrally with the rubber sheet 13, an elastically deformable elastic body 17 provided at a substantially central portion of a back surface (opposing surface) 15 b of the key main body 15, and an elastic body 17. A support portion 19 provided on the back surface 15b of the key body 15 located around the periphery, a substantially columnar protrusion portion 21 provided at the tip of the elastic body 17, and a protrusion portion so as to face the two electrode portions 11b. And a conducting portion 23 disposed at the tip of the head 21.
The key body 15 is biased in a direction away from the surface 11a of the circuit board 11 by the elastic force of the rubber sheet 13, and has a predetermined gap between the key body 15 and the circuit board 11 in a state where no external force is received. Has been placed. The key body 15 is inserted through an opening 2d formed in the housing 2 such that the surface 15a is exposed outward from the main surface 2a of the housing 2. The key body 15 can be brought close to the surface 11a of the circuit board 11 by elastically deforming the peripheral portion 13a thereof.

As shown in FIG. 3, the elastic body 17 is formed by forming a thin plate made of a metal material such as stainless steel into a substantially convex shape protruding from the back surface 15 b of the key body 15, and a tip wall portion to which the protrusion 21 is attached. 25, a side wall portion 27 extending from the back surface 15b of the key body 15 toward the peripheral edge of the front end wall portion 25, and a curved wall having a convex curved surface 29a disposed between the front end wall portion 25 and the side wall portion 27. Part 29.
The distal end wall portion 25 has a flat surface 25a facing the surface 11a of the circuit board 11, and the protrusion 21 is attached to the flat surface 25a. The curved wall portion 29 is formed over the entire periphery of the tip wall portion 25. Since the curved wall portion 29 has a smaller curvature than the distal end wall portion 25 and the side wall portion 27 extending substantially linearly, the curved wall portion 29 can be easily deformed. This is done by deforming the part 29.

The protrusion 21 is bonded to the tip wall 25 of the elastic body 17 and is preferably formed from a hard material that does not deform. This is because the curved wall 29 is surely elastically deformed without deforming the tip wall 25. The conducting portion 23 is made of a conductive material, and makes the two electrode portions 11b conductive with each other by contacting the two electrode portions 11b.
As shown in FIG. 2, the support portion 19 is formed in a substantially columnar shape and is bonded to the back surface 15 b of the key body 15. In a state where the key body 15 does not receive external force, the tip of the support portion 19 is located closer to the key body than the tip position of the conducting portion 23 with respect to the back surface 15b of the key body 15. That is, the height dimension of the support portion 19 with respect to the back surface 15 b of the key body 15 is smaller than the sum of the height dimensions of the elastic body 17, the protrusion portion 21, and the conduction portion 23.
The operation key unit 31 for performing the pressing operation is configured by the operation key 4 and the electrode portion 11b of the circuit board 11 configured as described above.

In the operation key unit 31 described above, when the key main body 15 is pressed, the peripheral portion 13a of the key main body 15 is elastically deformed, and as shown in FIG. 4, the conductive portion 23 straddles the two electrode portions 11b. The two electrodes 11b are brought into electrical contact with each other.
Thereafter, when the key body 15 is pushed down by applying further force from this contact state, the elastic body 17 is elastically deformed. That is, as shown in FIG. 5, the curved wall portion 29 disposed between the distal end wall portion 25 and the side wall portion 27 of the elastic body 17 is elastically deformed, and the distal end of the elastic body 17 is the key body 15. It will be dented to the back surface 15b side. This elastic deformation is instantaneously performed because the elastic body 17 is made of a thin metal plate.

In this elastic deformation, as shown in FIG. 4, the tip of the support portion 19 comes close to the surface 11 a of the circuit board 11, and the tip position of the conduction portion 23 with respect to the key body 15 and the support portion. The tip end position of the support portion 19 comes into contact with the surface 11 a of the circuit board 11 together with the conduction portion 23.
In this state, since the tip of the support portion 19 also presses the circuit board 11 in addition to the tip of the conduction portion 23, the force pressing the circuit board 11 by the key body 15 causes the tip of the conduction portion 23 and the support portion 19. Will be distributed to both ends. That is, it is preferable that the area of the tip of the support portion 19 that contacts the surface of the circuit board 11 is large.

As described above, according to the operation key unit 31, even if the key body 15 is further pushed down from the state in which the conducting portion 23 is in contact with the two electrode portions 11b, the elastic body 17 is elastically deformed to push down the key body 15 Therefore, it is possible to suppress the circuit board 11 from being pressed with an excessive force. Further, by providing the support portion 19, the force that presses the circuit board 11 by the key body 15 is distributed to both the front end of the conduction portion 23 and the front end of the support portion 19. It is possible to prevent the pressure from being concentrated on a part of the circuit board 11.
From the above, it is possible to prevent warping of the circuit board 11 due to the force pressing the circuit board 11 by the key body 15, damage of various electronic components mounted on the circuit board 11, and peeling of the electronic components from the circuit board 11. Can do.

In addition, when a failure occurs in the elastic body 17 or the conductive portion 23, it is only necessary to replace the operation key 4 formed on the rubber sheet 13 without replacing the circuit board 11 on which a large number of electronic components are mounted. The repair work of the operation key unit 31 can be easily performed. In addition, the defect of the elastic body 17 has shown that the elastic deformation of the elastic body 17 becomes inadequate, for example. Moreover, the defect of the conduction | electrical_connection part 23 has shown that the conduction | electrical_connection between the two electrode parts 11b becomes inadequate even if it contacts, for example.
Further, only the curved wall portion 29 of the elastic body 17 can be locally elastically deformed, and since this elastic deformation is instantaneously performed, a good click feeling can be obtained when the key body 15 is pushed down. Can do.

Further, since the protruding portion 21 made of a hard material is provided between the elastic body 17 and the conducting portion 23, when the key body 15 is further pushed down from the state where the conducting portion 23 is in contact with the electrode portion 11b, The curved wall portion 29 adjacent to the tip wall portion 25 can be reliably elastically deformed without deforming the tip wall portion 25.
Furthermore, by disposing the protrusion 21 between the elastic body 17 and the conductive portion 23, the distance between the surface 11a of the circuit board 11 and the opening 2d of the housing 2 is changed by the design of the mobile phone 1 or the like. However, the clearance between the conductive portion 23 and the electrode portion 11b can be changed as appropriate by changing only the length dimension of the protruding portion 21. For this reason, the key body 15, the elastic body 17, and the support portion 19 formed integrally with the rubber sheet 13 can be used for general purposes, and the manufacturing cost of the mobile phone 1 can be reduced.

In the above embodiment, the conducting portion 23 is attached to the tip of the elastic body 17 via the protrusion 21. However, the present invention is not limited to this, and the conducting portion 23 is attached to at least the tip of the elastic body 17. It only has to be. That is, the conduction part 23 may be directly attached to the flat surface 25a of the elastic body 17, for example.
In addition, the curved wall portion 29 is formed over the entire periphery of the tip wall portion 25, but the present invention is not limited to this, and it is sufficient that at least the side wall portion 27 is formed to support the tip wall portion 25. .
Moreover, although the elastic body 17 was formed from the metal thin plate, it is not restricted to this, It should just be formed from the material which can be elastically deformed at least. In other words, the elastic body 17 may be formed of an elastically deformable resin material.

Further, the key body 15 is biased outward from the casing 2 by the peripheral edge 13a of the key body. However, the present invention is not limited to this, and at least the key body 15 is biased outward from the interior of the casing 2. It only has to be done. That is, for example, an elastic member that can be elastically deformed may be attached to the tip of the support portion 19 and the key body 15 may be urged by the elastic member. In this configuration, when the key body 15 is released from being pressed, the elastic member is elastically restored, so that the key body 15 is urged toward the outer side of the housing 2.
In the case of this configuration, since the plurality of operation keys 4 can be independently formed without integrally providing the plurality of operation keys 4 on one rubber sheet 13, the elastic body 17 and the conductive portion 23 are provided. When a failure occurs, only the individual operation keys 4 need to be replaced, so that the repair work of the operation key unit 31 can be performed more easily.

Moreover, although the key main body 15, the elastic body 17, and the support part 19 were formed from separate members, the present invention is not limited thereto, and may be formed integrally with the rubber sheet 13, for example.
Furthermore, although the operation key unit 31 is provided in the mobile phone 1 including the single housing 2, the operation key unit 31 is not limited thereto, and may be provided in a mobile phone in which the two housings are connected to be superposed. However, it may be provided in various electronic devices such as PDAs, digital cameras, digital video cameras, and personal computers, and various electric devices such as electric fans, dryers, and electric toothbrushes.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

It is a perspective view which shows the mobile telephone carrying the operation key unit which concerns on one Embodiment of this invention. FIG. 2 is an enlarged cross-sectional view showing an operation key unit in the mobile phone of FIG. 1. FIG. 2 is an enlarged cross-sectional view showing an elastic body of an operation key unit in the mobile phone of FIG. 1. FIG. 2 is an enlarged cross-sectional view showing a state where an operation key of an operation key unit is pressed down in the mobile phone of FIG. 1. FIG. 2 is an enlarged cross-sectional view showing an elastic body in a state where an operation key of an operation key unit is pushed down in the mobile phone of FIG. 1. It is an expanded sectional view which shows an example of the conventional operation key unit.

Explanation of symbols

2 Housing 4 Operation key 11 Circuit board 11a Surface 11b Electrode part (switch pattern)
15 Key body 15b Back side (opposite side)
17 Elastic body 19 Support portion 23 Conducting portion 25 Tip wall portion 25a Flat surface 27 Side wall portion 29 Curved wall portion 29a Curved surface

Claims (4)

An operation key urged outward from the inside of the housing, and a switch pattern formed on the surface of the circuit board disposed inside the housing so as to face the operation key,
The operation key is disposed on a key body exposed to the outside of the casing, and on an opposing surface side of the key body having conductivity and facing the switch pattern, and the key body is disposed inside the casing. A conductive portion that makes contact with the switch pattern when the switch pattern is pushed down, and an elastically deformable elastic body that is disposed between the key body and the conductive portion. Operation key unit to perform.   2. The operation key unit according to claim 1, wherein the elastic body is formed by forming a metal thin plate into a substantially convex shape that protrudes from a facing surface of the key body toward the conductive portion.   The elastic body has a tip wall portion having a flat surface to which the conducting portion is attached, a side wall portion extending from the opposing surface of the key body toward the periphery of the tip wall portion, and between the side wall portion and the tip wall portion. The operation key unit according to claim 1, further comprising a curved wall portion formed and having a convex curved surface. The operation key includes a support portion that extends from the opposing surface of the key body toward the circuit board,
4. The operation key unit according to claim 1, wherein a tip end of the support portion is positioned closer to a key body side than a tip end position of the conduction portion from the facing surface. 5.

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