Keypad assembly and electronic device using the same

A keypad assembly includes a support member, a key switch, a keycap, and a resilient member. The key switch is fixed on the support member and includes a triggering portion. The keycap is located opposite to the triggering portion. The resilient member includes a rotation portion and a resilient support portion connected to the rotation portion. The rotation portion is rotatably connected to the keycap and the support member. The resilient support portion is elastically deformed via resisting the support member when the key switch is not triggered, and provides an elastic restoring force to the rotation portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to four co-pending U.S. patent application Ser. Nos. 12/913,006, 12/913,016, 12/915,280, 12/915,284, all entitled “KEYPAD ASSEMBLY AND ELECTRONIC DEVICE USING THE SAME”, and the inventor is Bin Dai. Such applications have the same assignee as the instant application and are concurrently filed herewith. The disclosures of the above-identified applications are incorporated herein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to data input, and particularly, to a keypad assembly used in an electronic device.

2. Description of the Related Art

Electronic devices often provide a keypad on a panel thereof, thus allowing control input for a power source or other component to be entered by the user.

A keypad assembly is located on a housing of an electronic device. The housing defines a mounting port in a rear surface of the housing. The keypad assembly includes a keycap and a key switch. The keycap is received in the mounting port, and includes a protrusion arranged at a bottom of the keycap. The key switch includes a triggering portion and a contact point. The triggering portion is a convex resilient sheet. The protrusion resists a top of the triggering portion. When the keycap is depressed, the triggering portion is elastically deformed and electrically connects to the contact point. When the keycap is released, the triggering portion returns to its relaxed state. However, a clearance can occur between the protrusion and the triggering portion, due to manufacturing tolerance or assembly error. The keycap slides in the mounting port without any resistance because of the clearance, such that the contact response of the keypad assembly is lowered.

Therefore, there is room for improvement within the art.

DETAILED DESCRIPTION

Referring toFIGS. 1 and 2, an embodiment of an electronic device100includes a housing101and a keypad assembly103located on the housing101. In the illustrated embodiment, the keypad assembly103is a menu button and the housing101is an outer case of the electronic device100. The housing101defines a mounting port102in the housing101. In the illustrated embodiment, the mounting port102is a through hole.

The keypad assembly103includes a keycap10, a fixing bracket20, a support member30, a key switch50, a resilient member60, and a fixing member70. The keycap10is partially received in the mounting port102. The fixing bracket20is fixed on an inner surface of the housing101adjacent to the mounting port102. The support member30is fixed to the fixing bracket20and located opposite to the mounting port102. The key switch50is fixed on the support member30. The resilient member60rotatably interconnects the keycap10and the fixing member70. The fixing member70is fixed to the support member30.

The keycap10includes a contact portion11, a limiting portion13and two connecting portions15. The contact portion11is substantially oblong and slidably received in the mounting port102. The limiting portion13is arranged at a side of the contact portion11. The limiting portion13is larger than the mounting port102, such that the contact portion11is retained within the mounting port102. The two connecting portions15are located at opposite ends of an outer surface of the limiting portion13. In the illustrated embodiment, each connecting portion15defines a pivotal hole151in the center of the corresponding connecting portion15and a gap152communicating with the pivotal hole151.

The fixing bracket20includes a first fixing portion21, two second fixing portions23, and a third fixing portion25. The first fixing portion21is substantially rectangular and fixed in an inner side of the housing101. The two second fixing portions23extend from opposite ends of the first fixing portion21, and are fixed to opposite ends of the third fixing portion25. The first fixing portion21, the second fixing portions23and the third fixing portion25cooperatively form a substantially closed bracket. In this embodiment, the first fixing portion21is fixed on an inner side of the housing101by welding. The third fixing portion25is used to fix other components (not shown) of the electronic device100.

The support member30includes a main body31and a support portion32located at the center of one side of the main body31. The main body31defines two through holes312in opposite ends of the main body31. The main body31is fixed on the second fixing portion23of the fixing bracket20via a plurality of threaded fasteners (not shown) received in the through holes312.

The key switch50is fixed on the support portion32of the support member30, and includes a triggering portion51. The limiting portion13of the keycap10contacts the triggering portion51to trigger the key switch50. In this embodiment, the key switch50is fixed on the support member30by welding.

The resilient member60includes a rotation portion61and a resilient support portion62. The rotation portion61and the resilient support portion62are substantially U-shaped, and each having two arms (not labeled). Opposite ends of the rotation portion61are connected to opposite ends of the resilient support portion62, such that the rotation portion61and the resilient support portion62cooperatively form a looped structure. The rotation portion61is larger than the resilient support portion62. In the illustrated embodiment, the resilient support portion62and the rotation portion61are not coplanar. The resilient member60is of an elastic wire.

The fixing member70includes a fixing portion71, two first hooks72, and two second hooks73. The two second hooks73are arranged on the fixing portion71. In another embodiment, the resilient member60is made from an elastic material.

Referring toFIGS. 2 and 3, during assembly of the keypad assembly103, a middle portion of the rotation portion61of the resilient member60is latched with the second hooks73of the fixing member70. Two of the arms of the resilient member60are latched in the first hooks72of the resilient member70. Opposite ends of the rotation portion61are received in the pivotal holes151of the keycap10via the gaps152, such that the rotation member60can be rotated relative to the keycap10. The first fixing portion21of the fixing bracket20is fixed on an inner side of the housing101. The opposite ends of the main body31of the support member30are connected to the two second fixing portions23of the fixing bracket20. The contact portion11of the keycap10is received in the mounting port102of the housing101. The key switch50is fixed on a side of the support member30.

When depressed, the keycap10slides toward the triggering portion51of the key switch50until the key switch50is triggered. When the keycap10is released, the triggering portion51of the key switch50returns to a relaxed state and resists the keycap10. The rotation portion61of the resilient member60rotates relative to the fixing member70at an angle, such that the resilient support portion62is elastically deformed via resisting the support member30and provides an elastic restoring force to the rotation portion61. Thus, the limiting portion13of the keycap10tightly contacts the triggering portion51of the key switch50, such that the keypad assembly103provides an acceptable resistance.

It should be pointed out that the elastic restoring force of the resilient member60is less than the biasing force provided by the keycap10, so that the key switch50is prevented from being triggered inadvertently.

It is to be understood that the fixing bracket20can also be omitted, correspondingly, whereby the support member30is fixed on an inner side of the housing101. The fixing member70can also be omitted, and the rotation portion61of the resilient member60is rotatably connected to the support member30; for example, the support member30defines a pivotal hole (not shown), and the rotation portion61passes through the pivotal hole.

Finally, while the present disclosure has been described with reference to particular embodiments, the description is illustrative of the disclosure and is not to be construed as limiting the disclosure. Therefore, various modifications can be made to the embodiments by those of ordinary skill in the art without departing from the true spirit and scope of the disclosure as defined by the appended claims.