Patent Publication Number: US-7714245-B2

Title: Keyswitch with balance member

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the invention 
   The present invention relates generally to a keyswitch, and more particularly, to a keyswitch with a balance member. 
   2. Description of the prior art 
   Generally, the keyswitch used in computer keyboard is constructed of a keycap, a substrate, and a scissors-like support disposed therebetween to support the keycap moving vertically opposite to the substrate. Moreover, when the keycap is moved downward to the substrate, it can trigger a switch disposed on the substrate. Said support has been fully disclosed in certain patent applications, as discussed in Taiwan Patent Number 319,438, entitled “Keyswitch with scissors-like support”. The above-mentioned structure is mainly suitable for square keyswitch. However, a balance member is needed for a longer keyswitch or a keyswitch with special shape (such as multiple key or functional keyswitch “space”, “shift”, or “enter”) to prevent said keyswitch tilt when a user presses on the edge of said keyswitch. 
   In the prior art, such as Taiwan Patent Number 346,213, entitled “Improved structure of multiple key”, and Taiwan Patent Number 411,004, entitled “Improved structure of balance member of multiple key”, the above-mentioned balance member is designed as U shape to perform said functionality. Please refer to  FIG. 1A , which illustrates the keycap and the balance member of the prior art. As shown in  FIG. 1A , the balance member  52  is engaged with the fixing portion  504  of the bottom surface  502  of the keycap  50 . 
   However, in practice, the keycap of the multiple key may be designed as a trapezium, a triangle or other polygon. Please refer to  FIG. 1B , which shows the keycap and the balance member in the prior art. As shown in  FIG. 1B , the appearance of the keycap  70  is substantially a trapezium. Accordingly, the conventional U-shaped balance member  72  can not cover the whole keycap  70 . Moreover, when an user presses on the edge (e.g. the portion marked with the dotted circle may tilt as mentioned above) of said keycap  70 , the keycap  70  may tilt, and the balance member  72  may even fail to drive the movement of the keycap  70  and further fail to trigger the switch disposed on the substrate. 
   SUMMARY OF THE INVENTION 
   Accordingly, a scope of the present invention is to provide a keyswitch comprising a balance member. Particularly, the balance member of the invention can be designed to fit the shape of keycap of the keyswitch to drive the movement of the keycap more completely than the conventional balance member does. 
   According to the first preferred embodiment, the keyswitch of the invention includes a keycap and a balance member. A bottom surface is defined on the keycap, and the bottom surface has at least a mounting portion. The balance member has an axle defining a first end and a second end opposite to the first end. The axle is folded with a first angle and elongated from the first end to form a first side, and the axle is folded with a second angle and elongated from the second end to form a second side. Additionally, the axle is mounted in the at least one mounting portion. Particularly, the second angle is between 30 degree and 60 degree. 
   Another scope of the present invention is to provide a keyboard comprises a plurality of keyswitches, and at least one of the keyswitches comprises a balance member. 
   According to the second preferred embodiment, the keyboard comprises a substrate, a plurality of switch, a plurality of support, a plurality of keycap and a balance member. The switches are disposed on the substrate, and each of the supports corresponds to one of the plurality of switches. Each of the supports has an upper engagement portion and a lower engagement portion. Each of the keycaps corresponds to one of the switches and one of the supports, and a bottom surface is defined on each of the keycaps. Moreover, at least one of the bottom surfaces has at least a mounting portion. The balance member has an axle defining a first end and a second end opposite to the first end. The axle is folded with a first angle and elongated from the first end to form a first side, and the axle is folded with a second angle and elongated from the second end to form a second side. Furthermore, the axle is mounted in the at least one mounting portion. Particularly, the second angle is between 30 degree and 60 degree. 
   Additionally, each of the supports is mounted to the bottom surface by the upper engagement portion and is mounted to the substrate by the lower engagement portion, so as to support the corresponded keycap moving vertically opposite to the substrate. Moreover, each of the switches is selectively turned on in response to the movement of the keycap. 
   The objective of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment, which is illustrated in the various figures and drawings. 

   
     BRIEF DESCRIPTION OF THE APPENDED DRAWINGS 
       FIG. 1A  illustrates the keycap and the balance member in the prior art. 
       FIG. 1B  illustrates the keycap and the balance member in the prior art. 
       FIG. 2  illustrates the keycap and the balance member of the keyswitch of an embodiment of the invention. 
       FIG. 3  illustrates the balance member of the invention. 
       FIG. 4  illustrates the balance member of the invention. 
       FIG. 5A  illustrates that the keycap and the balance member in  FIG. 2  are configured on a substrate. 
       FIG. 5B  is a cross-section diagram illustrating the keyswitch in  FIG. 5A . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Please refer to  FIG. 2  and  FIG. 3 .  FIG. 2  illustrates the keycap and the balance member of the keyswitch of an embodiment of the invention; and  FIG. 3  further illustrates the balance member. In the embodiment, the keyswitch  1  includes a keycap  10  and a balance member  12 . A bottom surface  102  is defined on the keycap  10 , and the bottom surface  102  has two mounting portions  104 . 
   The balance member  12  has an axle  122  defining a first end and a second end opposite to the first end. The axle  122  is folded with a first angle θ 1  and elongated from the first end to form a first side  124 , and the axle  122  is folded with a second angle θ 2  and elongated from the second end to form a second side  126 . As shown in  FIG. 2 , the axle  122  is mounted in these mounting portions  104 , so that the axle  122  can rotate relatively to the keycap  10 . Particularly, the second angle θ 2  is between 30 degree and 60 degree, such as 45 degree. 
   In an embodiment, the keyswitch of the invention further includes a substrate, a switch and a support. The substrate has a first connecting member and a second connecting member. The switch is disposed on the substrate. The support can be used to support the keycap moving vertically opposite to the substrate. The support has an upper engagement portion coupled to the bottom surface, and a lower engagement portion coupled to the substrate. 
   Furthermore, the first side and the second side of the balance member are connected to the first connecting member and the second connecting member respectively. The switch is selectively turned on in response to the movement of the keycap. For example, when the keycap is pressed downward to the substrate, the switch will be turned on; and when the keycap is released from the pressed position, the switch will be turned off. 
   Please refer to  FIGS. 5A and 5B ,  FIG. 5A  illustrates that the keycap and the balance member in  FIG. 2  are configured on a substrate, and  FIG. 5B  is a cross-section diagram illustrating the keyswitch in  FIG. 5A . As shown in  FIG. 5A  and  FIG. 5B , in addition to the keycap  10  and the balance member  12 , the keyswitch  1  further comprises a substrate  14 , a switch  16 , and a support  18 . A first connecting member  140  and a second connecting member  142  are configured on the substrate  14 , and the first side  124  and the second side  126  of the balance member  12  are connected to the first connecting member  140  and the second connecting member  142  respectively. The support  18  is coupled to the bottom surface  102  of the keycap  10  by an upper engagement portion  180  and coupled to the substrate  14  by a lower engagement portion  182  for supporting the keycap  10  moving vertically opposite to the substrate  14 . When the keycap  10  moves, the switch  16  could be triggered to make the switch  16  to be turned on. 
   Please refer to  FIG. 4 , which shows the balance member of an embodiment of the invention. In the embodiment, a third end is defined on the second side  126  of the balance member  12 , and the second side  126  is folded with a third angle θ 3  and elongated from the third end to form a third side  128 . 
   Furthermore, in the embodiment, the balance member  12  is connected to the above-mentioned first connecting member and second connecting member by the first side  124  and the third side  128 , so as to cooperate with the support to support the movement of the keycap. 
   Practically, the above-mentioned first angle θ 1  is substantially equal to 90 degree, and the second angle θ 2  is substantially equal to 45 degree. However, in practice, the first angle, the second angle and the third angle can optionally be adjusted to any other suitable degree. 
   In a preferred embodiment, the invention further provides a keyboard with the above-mentioned keyswitches. The keyboard includes a substrate, a plurality of switches, a plurality of supports, a plurality of keycaps and at least a balance member. 
   The switches are disposed on the substrate, and each of the supports corresponds to one of the switches. Each support has an upper engagement portion and a lower engagement portion. Each of the keycaps corresponds to one of the switches and one of the supports, and a bottom surface is defined on the keycap. Particularly, at least one of the bottom surfaces has at least a mounting portion. 
   The balance member has an axle defining a first end and a second end opposite to the first end. The axle is folded with a first angle and elongated from the first end to form a first side, and the axle is folded with a second angle and elongated from the second end to form a second side. Moreover, the axle is mounted in the at least one mounting portion. Additionally, as mentioned above, the second angle is between 30 degree and 60 degree. 
   Furthermore, each of the supports is mounted to the bottom surface by the upper engagement portion and is mounted to the substrate by the lower engagement portion, so as to support the corresponded keycap moving vertically opposite to the substrate. Moreover, each of the switches is selectively turned on in response to the movement of the corresponded keycap. 
   In an embodiment, the substrate of the keyboard further has a first connecting member and a second connecting member opposite to the first connecting member. The first side and the second side of the balance member are connected to the first connecting member and the second connecting member respectively. Accordingly, the balance member can cooperate with the support to support the movement of the keycap. 
   In another embodiment, the substrate of the keyboard further has a first connecting member and a second connecting member opposite to the first connecting member. Furthermore, as shown in  FIG. 4 , a third end is defined on the second side of the balance member, and the second side is folded with a third angle and elongated from the third end to form a third side. The first side and the third side of the balance member are connected to the first connecting member and the second connecting member respectively. Accordingly, the balance member can cooperate with the support to support the movement of the keycap. 
   Practically, the above-mentioned first angle θ 1  is substantially equal to 90 degree, and the second angle θ 2  is substantially equal to 45 degree. However, in practice, the first angle, the second angle and the third angle can optionally be adjusted to any other suitable degree. 
   Practically, the keyswitch with the balance member of the invention can be, but not limited to multiple key, such as “space”, “shift”, “enter”, or “backspace”; or keys with irregular shape, such as “enter”. 
   To sum up, the balance member of the invention can fit keyswitches with different shape, so as to drive the movement of the keycap more completely than the conventional balance member does. 
   Although the present invention has been illustrated and described with reference to the preferred embodiment thereof, it should be understood that it is in no way limited to the details of such embodiment but is capable of numerous modifications within the scope of the appended claims.