Patent Application
20140001021
1. Field of the Invention
This invention relates to a press key, more particularly to a single press key capable of executing different commands.
2. Description of the Related Art
A conventional press key includes a base plate, a circuit board disposed on the base plate, a keycap disposed on the circuit board, and a rubber dome constantly providing an elastic restoring force and disposed between the keycap and the circuit board. The circuit board includes a switch for triggering a key signal. The rubber dome includes a pressing unit protruding downward and able to press the switch. While the rubber dome is elastically deformed, the pressing unit contacts and presses the switch of the circuit board so as to generate the key signal.
With the innovation of electronic products (such as, laptop, desktop computer and so on), the electronic products are required to have more functions, and thus the number of the press keys on the electronic products is increased. Excessive press keys occupy relatively large space, and result in an increased keyboard area on the electronic products.
Moreover, the current design trend is toward becoming thinner, lighter, smaller, and more portable. Thus, each of the press keys should be designed to have a smaller pressing area in accordance with the miniaturization of the electronic products. However, it is inconvenient for a user to press the press keys with smaller pressing areas. For example, the user may fail to precisely press the desired press keys or may mispress multiple press keys simultaneously.
Hence, there is a requirement to integrate multiple functions into a single press key. A multi-orientation press key has been proposed in Taiwanese Patent No. 1329331 to execute different commands. In this patent, two different positions on the multi-orientation press key can be pressed to turn on two different switches so as to generate different key signals. However, in order to provide two different pressing positions on the multi-orientation press key, the multi-orientation press key should have a relatively large pressing area. As such, the aim of reducing areas of press keys in the keyboard of the electronic product cannot be desirably achieved. Besides, because the user is accustomed to fast pressing a press key, the pressing of the multi-orientation press key does not conform with the typing habit of the user. Therefore, the multi-orientation press key is unfavorable for the miniaturization of the electronic products and for the fast typing.
Therefore, an object of the present invention is to provide a press key that can overcome the aforesaid drawbacks associated with the prior art.
Accordingly, a press key according to this invention comprises:
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments of the invention, with reference to the accompanying drawings, in which:
Before the present invention is described in greater detail with reference to the accompanying preferred embodiments, it should be noted herein that like elements are denoted by the same reference numerals throughout the disclosure.
Referring to
The circuit board 2 is disposed on the base plate 1 and includes first and second switches 21 and 22, a deformable upper layer 23, a lower layer 24, and a spacer unit 25 to space apart the upper and lower layers 23, 24.
The first and second switches 21, 22 are spaced apart from each other. The first switch 21 has an upper contact 211 disposed on a bottom surface of the upper layer 23, and a lower contact 212 disposed on a top surface of the lower layer 24. The lower contact 212 is spaced apart from the upper contact 211 and is aligned with the upper contact 211 along a direction shown by an arrow A. The second switch 22 has an upper contact 221 disposed on the bottom surface of the upper layer 23, and a lower contact 222 disposed on the top surface of the lower layer 24. The lower contact 222 is spaced apart from the upper contact 221 and is aligned with the upper contact 221 along the direction shown by the arrow A.
With the flexible deformation of the upper layer 23, the upper contact 211 of the first switch 21 can be brought into contact with the lower contact 212 of the first switch 21, and the upper contact 221 of the second switch 22 can be brought into contact with the lower contact 222 of the second switch 22. Alternatively, the first and second switches 21, 22 maybe replaced by other types of contact switches or sensitive switches (for example, capacitance switches).
The insulating film 3 is disposed on the circuit board 2, and is constituted by a mylar film. In other preferred embodiment, the insulating film 3 may be made of other insulation plastic materials.
The pressing unit 4 includes a keycap 41 disposed on the circuit board 2, an elastic element 42 disposed between the keycap 41 and the circuit board 2, and a scissors-type linkage assembly 43 disposed between the keycap 41 and the base plate 1 to surround the elastic element 42. The keycap 41 is normally in a raised position (see
As best shown in
In other embodiments, the scissors-type linkage assembly 43 may be replaced by other modified structures as long as the modified structures can stably guide the keycap 41 to move upward and downward with respect to the base plate 1.
The first and second trigger members 5 and 6 are spaced apart from each other, and are connected to the pressing unit 4 so as to be able to move toward and contact the circuit board 2, thereby turning on the first and second switches 21 and 22, respectively.
It should be noted that a distance between the first trigger member 5 and the first switch 21 is shorter than a distance between the second trigger member 6 and the second switch 22.
When an external force is applied to the keycap 41 to move the keycap 41 to the first pressed position (FIG. 3), the first trigger member 5 moves downwardly to contact the upper layer 23 so as to deform a first portion of the upper layer 23 that is at a position corresponding to the first trigger member 5. Accordingly, the upper contact 211 of the first switch 21 is brought into contact with the lower contact 212 of the first switch 21 by the first trigger member 5 to turn on the first switch 21, thereby generating a first key signal. At this moment, the second trigger member 6 is spaced apart from the second switch 22.
When a greater external force is applied to the keycap 41 to move the keycap 41 to the second pressed position (
Accordingly, the press key of this invention can produce two different key signals by applying different amounts of force to move the keycap 41 to different positions. That is to say, in this invention, a single press key can be used to execute two different commands. In this embodiment, the first trigger member 5 is a protrusion extending downwardly from an inner surface of a top side of the inverted bowl-shaped body of the elastic member 42, and is formed in one-piece with the elastic element 42. Alternatively, the first trigger member 5 may be an independent element connected to the elastic element 42.
The second trigger member 6 is a protrusion extending downwardly from a lower side of the keycap 41, and is formed in one-piece with the keycap 41. Alternatively, the second trigger member 6 may be an independent element connected to the keycap 41.
In other embodiments, the circuit board 2 is a signal layer (not shown), and each of the first and second switches 21 and 22 has two spaced apart contacts (not shown) on the signal layer of the circuit board 2. Each of the first and second trigger members 5 and 6 has a conductive bottom end (not shown). When the first trigger member 5 moves to the first switch 21, the two spaced apart contacts are electrically connected through the first trigger member 5, thereby turning on the first switch 21. The second switch 22 can also be turned on in a similar manner.
While the present invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements.
