The present invention relates to a keyboard and particularly to a thin keyboard with connection arms to bridge keycaps to reduce keyboard thickness.
There are numerous types of input devices for computer systems, such as optical disk drives, mouse, keyboards and the like. Among them keyboards are most commonly used. A conventional keyboard, such as one disclosed in R.O.C. patent Nos. 445471, 1220213 and M346861, generally includes a keycap, a circuit board triggered by the keycap to generate a command signal, a baseboard located at one side of the circuit board, and a driven mechanism with two ends connecting to the keycap and baseboard. In the aforesaid keyboard structure, the keycap receives a force to move against the circuit board. The driven mechanism is depressed downwards to press and set on a circuit switch on the circuit board to generate a corresponding control signal. When the keycap does not receive the force and not move towards the circuit board, the driven mechanism provides a return elastic force to push the keycap away from the circuit board at a selected elevation relative to the circuit board in a regular condition. Although the keyboard thus formed can achieve the object of entering commands, the driven mechanism is formed at a certain height that is added to the height of the keyboard. There days requirements of computer design heavily focus on thin and lightweight. Take a notebook computer for instance, the thickness of the keyboard module is the major factor affecting the total thickness of the notebook computer. Almost all computer makers have devoted a great deal of efforts and investments trying to make the keyboard structure thinner.
To overcome the aforesaid problem, other types of keyboard designs have been proposed. For instance, R.O.C. patent M434979 discloses a keycap formed in a V-shaped structure by coupling a first support member and a second support member to overcome the thickness problem created by the X-shaped structure of the conventional driven mechanism. R.O.C. patent M419973 discloses an extensible lift structure between the keycap and circuit board to substitute the conventional driven mechanism to facilitate miniaturization. R.O.C. patent M426075 proposes a keycap surrounded by a first support member and a second support member to substitute the conventional driven mechanism to reduce total keyboard thickness. Eventually, all the aforesaid techniques merely try to change the implementation approach of the driven mechanism. They still have substantial thickness, and the structures are quite complex and assembly is difficult.
The primary object of the present invention is to provide a thin keyboard with connection arms to bridge keycaps to overcome the thickness problem of the conventional keyboards caused by the driven mechanism that makes thinning impossible.
To achieve the foregoing object the present invention provides a thin keyboard which includes at least one circuit board and a plurality of keycap assembly located on the circuit board and movable vertically to press the circuit board to generate keyboard command signals. The keycap assembly includes a plurality of first keycaps and second keycaps abutting each other. The abutting first keycap and second keycap are interposed by a plurality of connection arms. Each connection arm includes at least one first connecting section connecting to the first keycap, at least one second connecting section connecting to the second keycap and an elastic section which bridges the first connecting section and second connecting section and contains at least one stress reversion spot.
In one embodiment the thin keyboard further includes a frame which has at least one housing zone to hold the keycap assembly. The first keycap or second keycap and the abutting the frame are bridged by the connection arm. The keycap assembly is held in the housing zone and arranged in a horizontal or vertical manner. The keycap assembly includes a support rib located between the neighboring housing zones. More specifically, the frame and support rib include a retaining portion abutting the circumference of the first keycap and second keycap to form a retaining zone. The retaining portion is located correspondingly to a side corner position of the first keycap and second keycap, or correspondingly to a lateral side of the first keycap and second keycap where no connection arm is located.
In another embodiment the first keycap and second keycap have a depressible first upper surface and a lower surface. The lower surface has a contact portion extended towards the circuit board.
In yet another embodiment the first keycap and second keycap and the circuit board are interposed by a movement zone. The movement zone contains an elastic support member to aid movements of the first keycap and second keycap relative to the circuit board. More specifically, the elastic support member includes a trigger portion depressible by the first keycap or second keycap to connect the circuit board to generate the keyboard command signals. The elastic support member can be located in the center or one of four corners of the first keycap and second keycap.
In yet another embodiment the frame includes a support arm between the first keycap and second keycap to connect to the elastic section to provide ancillary support.
In yet another embodiment the connection arm bridges opposing lateral sides of the first keycap and second keycap.
In yet another embodiment the first keycap and second keycap include a depressible first upper surface, a second upper surface formed at an elevation difference against the first upper surface, and a lower surface facing the circuit board. The connection arm bridges opposing lateral sides of the second upper surface of the first keycap and second keycap.
Through the aforesaid structure, compared with the conventional keyboards, the invention provides features as follow:
1. Total keyboard thickness can be reduced. The invention has a connection arm located between the first keycap and second keycap to provide a return force after the first and second keycaps are depressed to replace the conventional driven mechanism, hence the problem of thickness constraint caused by the driven mechanism can be overcome, and the keyboard can be made thinner.
2. Assembly of the keyboard is simpler. Through the connection arm provided by the invention, assembly can be accomplished without inter-latching of multiple structures, hence the keyboard can be assembled easier.
3. Simplified keyboard structure. Compared with the conventional keyboard relied on a baseboard and a driven mechanism that require a lot of related assembly structures, the thinner keyboard of the invention does not have driven mechanism, hence there is also no related assembly work on the baseboard. As a result, assembly operation of the thin keyboard is simpler.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
Please referring to
It is to be noted that the thin keyboard mentioned herein can be assembled in many ways, only one type of assembly process is taken as an example for discussion in this invention, but not the limitation of the invention. Fabrication and assembly process of the invention is elaborated as follow:
a). circuit board fabrication step: provide the circuit board 1 including a plurality of command portions 11 to generate keyboard command signals;
b). keycap fabrication step: fabricate a frame 5 and a plurality of first keycaps 2 and second keycaps 3 located in the frame 5 via an integrated injection process. The frame 5 and first keycaps 2 and second keycaps 3 are bridged by a material injection strip 51 formed during the injection process. More specifically, the abutting first keycap 2 and second keycap 3 are interposed by the connection arms 4. Each connection arm 4 has at least one first connecting section 41 connecting to the first keycap 2 and one second connecting section 42 connecting to the second keycap 3. The first connecting section 41 and second connecting section 42 are bridged by the elastic section 43 which contains at least one stress reversion spot A; and
c). keycap and circuit board assembly step: assemble the frame 5 and circuit board 1, with the first keycaps 2 and second keycaps 3 on the frame 5 aligned with the command portions 11 of the circuit board 1; then sever the material injection strip 51 between the frame 5 and first keycaps 2 or second keycaps 3 via a preset equipment (not shown in the drawings) to finish fabrication of the thin keyboard of the invention.
For assembly of the thin keyboard, place the circuit board 1 in a keyboard housing 6, then assemble the frame 5 and keyboard housing 6. Referring to
The connection arm 4, aside from the embodiment previously discussed, can also be changed as desired according to user's keystroke feel or intended elastic return degree. The connection arm 4 has at least one stress reversion spot A.
Please referring to
Please referring to
Please referring to
Please referring to
As a conclusion, the simple assembly thin keyboard of the invention mainly employs the connection arm between the first and second keycaps to substitute the conventional driven mechanism to generate the same effect, hence the thickness of the keyboard can be reduced. Without the height constraint of the driven mechanism, the keyboard can be made thinner and lighter in weight, and also can be adaptable to other products with design requirements of thin and lightweight.
While the preferred embodiments of the invention have been set forth for the purpose of disclosure, they are not the limitations of the invention, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.