Patent Publication Number: US-9905380-B2

Title: Magnetic type keyboard and magnetic key thereof

Description:
FIELD OF THE INVENTION 
     The present invention relates to a magnetic type keyboard and a magnetic key, and more particularly to a magnetic type keyboard and a magnetic key using a lateral or horizontal magnetic force to return a keycap to its original position. 
     BACKGROUND OF THE INVENTION 
     As known, computers such as desktop computer (e.g., personal computers) or notebook computers become essential tools in our daily lives. Moreover, keyboards are important input devices of computers. Via the keyboards, users can input characters or perform control operations. Generally, a keyboard comprises plural keys. These keys are located at specified positions. Moreover, many electronic devices or electrical operation devices are equipped with keys that are used as operation interfaces of performing various designated functions. 
     For allowing users to perform the input and control operations, the keys of the keyboard are specially designed. That is, in response to a single depressing action, the key is returned to its original position and a triggering signal is generated in response to the depressing action. As for the conventional keyboards, the keys are classified according to the types of the switches in the keys. For example, the keys are classified into some types, including mechanical keys, membrane keys, conductive rubber keys and contactless electrostatic capacitive keys. The use lives, tactile feels and fabricating cost for different types of keys are usually different. 
     With increasing development of science and technology, the trends of designing electronic devices are toward light weightiness and slimness. That is, the thickness of the key of the electronic device is gradually reduced. However, for providing the position-returning function, the overall volume of the conventional key is still large. Moreover, the conventional key has some drawbacks such as the stuck key problem, the impaired tactile feel or the high fabricating cost. For solving these drawbacks, a magnetic type keyboard with magnetic keys is introduced into the market. The magnetic keys can be applied to the slim-type electronic devices. Moreover, the magnetic keys can provide special depressing feels to users. For example, the associated technologies are disclosed in Chinese utility model patent Nos. CN103065846 and CN204204708. 
     The structure features and position-returning principles of the magnetic key of the conventional magnetic type keyboard will be described as follows. At least two magnets are located at two opposite sides of an outer periphery of a keycap, and at least two magnets are formed on a keyboard frame at the positions corresponding to the magnets on the outer periphery of the keycap in the vertical direction. Since the magnets on the outer periphery of the keycap and the magnets on the keyboard frame are magnetically attracted by each other in the vertical direction, the keycap can be returned to its original position after the keycap is depressed. The magnetic attraction force generated by these magnets is in parallel with the direction of depressing the keycap. Moreover, the magnetic attraction between two magnets can be replaced by the magnetic attraction between a magnet and a paramagnetic material. 
     Since the keycap of the key is depressed in the vertical direction, it is necessary to reserve a proper space between the keycap and the keyboard base so as to accommodate the depressed keycap. As mentioned above, the magnetic key of the conventional magnetic type keyboard is equipped with magnets on the outer periphery of the keycap magnets on the keyboard frame along the direction of depressing the keycap. Moreover, the buffering space for accommodating the depressed keycap is required. In other words, the overall thickness and volume of the key structure are very large. The large thickness and volume of the key structure are detrimental to the slimness of the keyboard or the electronic device. 
     SUMMARY OF THE INVENTION 
     For overcoming the drawbacks of the conventional technologies, the present invention provides a magnetic type keyboard and a magnetic key. The magnetic key uses a lateral or horizontal magnetic force to return a keycap to its original position. Since the thickness and volume of the magnetic key are effectively reduced, the magnetic type keyboard and the magnetic key can meet the slimness requirement. 
     In accordance with an aspect of the present invention, there is provided a magnetic type keyboard. The magnetic type keyboard includes plural magnetic keys. Each magnetic key includes a keycap, a base plate, a membrane circuit member, a frame, a first magnetic element, a second magnetic element, and a third magnetic element. The keycap can be depressed. The membrane circuit member is disposed over the base plate. The frame is disposed over the base plate and the membrane circuit member. The frame includes a first concave structure, a second concave structure and an opening. The keycap is movably inserted in the opening. The frame has an accommodation space. The first magnetic element is disposed on the base plate and received within the first concave structure. The second magnetic element is disposed on the base plate and received within the second concave structure. The third magnetic element is disposed under the keycap and accommodated within the accommodation space. In response to a first magnetic force between the third magnetic element and the first magnetic element and a second magnetic force between the third magnetic element and the second magnetic element, the keycap is driven to be protruded out of the opening. 
     In accordance with another aspect of the present invention, there is provided a magnetic key. Each magnetic key includes a keycap, a base plate, a membrane circuit member, a frame, a first magnetic element, a second magnetic element, and a third magnetic element. The keycap can be depressed. The membrane circuit member is disposed over the base plate. The frame is disposed over the base plate and the membrane circuit member. The frame includes a first concave structure, a second concave structure and an opening. The keycap is movably inserted in the opening. The frame has an accommodation space. The first magnetic element is disposed on the base plate and received within the first concave structure. The second magnetic element is disposed on the base plate and received within the second concave structure. The third magnetic element is disposed under the keycap and accommodated within the accommodation space. In response to a first magnetic force between the third magnetic element and the first magnetic element and a second magnetic force between the third magnetic element and the second magnetic element, the keycap is driven to be protruded out of the opening. 
     The above objects and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic top view illustrating a magnetic type keyboard according to an embodiment of the present invention; 
         FIG. 2  is a schematic perspective view illustrating a magnetic key of the magnetic type keyboard of  FIG. 1 ; 
         FIG. 3A  is a schematic exploded view illustrating the magnetic key of  FIG. 2 ; 
         FIG. 3B  is a schematic exploded view illustrating the magnetic key of  FIG. 3A  and taken along another viewpoint; 
         FIG. 4  is a schematic cutaway view illustrating the magnetic key of  FIG. 2 ; 
         FIG. 5A  is a schematic side cross-sectional view illustrating the magnetic key of  FIG. 2 , in which the magnetic key is in a non-depressed state; 
         FIG. 5B  is a schematic side cross-sectional view illustrating the magnetic key of  FIG. 2 , in which the magnetic key is in a depressed state; and 
         FIG. 6  is a schematic side cross-sectional view illustrating a magnetic key according to another embodiment of the present invention, in which the magnetic key is in a depressed state. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for purpose of illustration and description only. In the following embodiments and drawings, the elements irrelevant to the concepts of the present invention are omitted and not shown. 
     Hereinafter, an example of a magnetic type keyboard will be illustrated with reference to  FIG. 1 .  FIG. 1  is a schematic top view illustrating a magnetic type keyboard according to an embodiment of the present invention. As shown in  FIG. 1 , the magnetic type keyboard  100  comprises plural magnetic keys  1 . These magnetic keys  1  are arranged at the designated positions according to characters or functions. The magnetic type keyboard  100  of this embodiment can be applied to a computer host or an electronic device. Via the magnetic type keyboard  100 , users can input characters or perform control operations. Moreover, the sizes and shapes of the magnetic keys  1  shown in  FIG. 1  can be identical or different according to the practical requirements. 
     In accordance with a feature of the present invention, the keycaps of these magnetic keys  1  are returned to their positions according to magnetism. Particularly, the position-returning function of the keycap is achieved according to the magnetic attraction of magnets. In this present invention, the key of the keyboard is taken as an example. It is noted that the concepts of the present invention can be applied to the equipment or device with the key having the position-returning function in response to a single depressing action. 
       FIG. 2  is a schematic perspective view illustrating a magnetic key of the magnetic type keyboard of  FIG. 1 . Please refer to  FIGS. 1 and 2 . The magnetic type keyboard  100  comprises a casing  101 . Each of the magnetic keys  1  comprises a frame  10 . Moreover, all magnetic keys  1  are installed on the casing  101 , or the frame  10  of each magnetic key  1  is considered as a part of the casing  101 . Each frame  10  has an opening  13 . Each magnetic key  1  comprises a keycap  20 . The keycap  20  can be depressed by the user. In addition, the keycap  20  is movably inserted in the corresponding opening  13 . 
     Please refer to  FIGS. 3A, 3B, 4, 5A and 5B .  FIG. 3A  is a schematic exploded view illustrating the magnetic key of  FIG. 2 .  FIG. 3B  is a schematic exploded view illustrating the magnetic key of  FIG. 3A  and taken along another viewpoint.  FIG. 4  is a schematic cutaway view illustrating the magnetic key of  FIG. 2 .  FIG. 5A  is a schematic side cross-sectional view illustrating the magnetic key of  FIG. 2 , in which the magnetic key is in a non-depressed state.  FIG. 5B  is a schematic side cross-sectional view illustrating the magnetic key of  FIG. 2 , in which the magnetic key is in a depressed state. 
     As shown in these drawings, the magnetic key  1  further comprises a base plate  30 , a membrane circuit member  33 , a first magnetic element  41 , a second magnetic element  42 , a third magnetic element  43 , and two positioning elements  21  and  22 . The membrane circuit member  33  is disposed over the base plate  30 . The frame  10  is disposed over the base plate  30  and the membrane circuit member  33 . The positioning elements  21  and  22  are disposed under the keycap  20 . The base plate  30  comprises a first protrusion structure  31  and a second protrusion structure  32 . The frame  10  further comprises a first concave structure  11  and a second concave structure  12 . The first concave structure  11  and the second concave structure  12  correspond to the first protrusion structure  31  and the second protrusion structure  32 , respectively. During the process of assembling the magnetic key  1 , the first concave structure  11  and the second concave structure  12  are respectively aligned with the first protrusion structure  31  and the second protrusion structure  32 , and an accommodation space  10   a  is defined by the frame  10 , the first protrusion structure  31  and the second protrusion structure  32  collaboratively. The opening  13  is in communication with the accommodation space  10   a . Moreover, the first concave structure  11  and the second concave structure  12  are on two opposite sides of the accommodation space  10   a.    
     Moreover, the first magnetic element  41  is disposed on the first protrusion structure  31  and received within the first concave structure  11 , and the second magnetic element  42  is disposed on the second protrusion structure  32  and received within the second concave structure  12 . In this embodiment, the height H 1  of the first protrusion structure  31  and the height H 2  of the second protrusion structure  32  are equal. That is, the distance between the first magnetic element  41  and the base plate  30  (or the membrane circuit member  33 ) and the distance between the second magnetic element  42  and the base plate  30  (or the membrane circuit member  33 ) are equal. In case that the sizes or thicknesses of the first magnetic element  41  and the second magnetic element  42  are identical, the magnetic influence of the first magnetic element  41  on the accommodation space  10   a  and the magnetic influence of the second magnetic element  42  on the accommodation space  10   a  are substantially identical. 
     Moreover, it is important to precisely position the distance or height. For allowing the third magnetic element  43  to effectively position the first magnetic element  41  and the second magnetic element  42 , the magnetic key  1  further comprises the two positioning elements  21  and  22 . The positioning elements  21  and  22  are fixedly embedded within recesses  201  and  202  that are formed in a bottom surface of the keycap  20 . The third magnetic element  43  is disposed under the positioning elements  21  and  22 . For example, by adjusting the thicknesses of the positioning elements  21  and  22  between the keycap  20  and the third magnetic element  43 , the magnetic influences between these magnetic elements  41 ,  42  and  43  can be correspondingly controlled. Consequently, the key  20  can be smoothly protruded out of the keycap  20  to be depressed by the user. 
     Moreover, since the keycap  20  is movably inserted in the opening  13 , the size of the keycap  20  is smaller than the size of the opening  13 . Preferably, the width W 1  of the third magnetic element  43  is equal to the distance D 1  between the first magnetic element  41  and the second magnetic element  42 . Consequently, when the keycap  20  is returned to its original position or the keycap  20  is in a non-depressed position, the purpose of effectively fixing the keycap  20  and avoiding falling down the keycap  20  can be achieved. After the positioning elements  21  and  22  and the third magnetic element  43  under the keycap  20  are placed in the accommodation space  10   a , a first magnetic force F 1  between the third magnetic element  43  and the first magnetic element  41  and a second magnetic force F 2  between the third magnetic element  43  and the second magnetic element  42  are generated. In response to the first magnetic force F 1  and the second magnetic force F 2 , the keycap  20  is driven to be protruded out of the opening  13 . 
     In an embodiment, the first magnetic element  41 , the second magnetic element  42  and the third magnetic element  43  are magnets, and the positioning elements  21  and  22  are made of a paramagnetic material. The paramagnetic material is a material that is magnetically attracted in the presence of a magnetic field of a magnet. For example, the paramagnetic material is a metallic material. Consequently, after the positioning elements  21  and  22  are fixedly embedded within the keycap  20 , the third magnetic element  43  and the positioning elements  21  and  22  are magnetically attracted by each other, and the third magnetic element  43  is fixed on the bottom surfaces of the positioning elements  21  and  22 . 
     As mentioned above, the first magnetic element  41 , the second magnetic element  42  and the third magnetic element  43  are magnets. For generating the first magnetic force F 1  and the second magnetic force F 2 , unlike poles of the first magnetic element  41 , the second magnetic element  42  and the third magnetic element  43  are arranged beside each other. For example, the south pole of the first magnetic element  41  faces the north pole of the third magnetic element  43 , and the north pole of the second magnetic element  42  faces the south pole of the third magnetic element  43 . Please refer to  FIGS. 4 and 5A . When the keycap  20  is not depressed, the third magnetic element  43  is magnetically attracted by the first magnetic element  41  and the second magnetic element  42  in response to the first magnetic force F 1  and the second magnetic force F 2 . 
     Please refer to  FIG. 5B . While a depressing force F 0  exerted on the keycap  20  overcomes the first magnetic force F 1  and the second magnetic force F 2 , the third magnetic element  43  is moved relative to the first magnetic element  41  and the second magnetic element  42 . Consequently, the keycap  20  is moved toward the base plate  30  or the accommodation space  10   a  is shrunken. For moving the third magnetic element  43  downwardly, the width of the accommodation space  10   a  is larger than or equal to the width W 1  of the third magnetic element  43 . In this embodiment, an electrically-conductive structure  431  is formed on a bottom surface of the third magnetic element  43 . For example, the bottom surface of the third magnetic element  43  is coated with a thin layer of electrically conductive material. As the keycap  20  is depressed by the user and moved toward the base plate  30 , the electrically-conductive structure  431  is contacted with the membrane circuit member  33 . Consequently, the membrane circuit member  33  is electrically conducted to generate a triggering signal. According to the triggering signal, a corresponding input operation or control operation is performed. 
     As mentioned above, the height H 1  of the first protrusion structure  31  (or the height of the second protrusion structure  32 ) and the movable depths of the keycap  20  and the third magnetic element  43  within the accommodation space  10   a  are specially designed according to the influence ranges of the first magnetic force F 1  and the second magnetic force F 2 . As shown in  FIG. 5B , the magnetic key is in the depressed state. Even if the third magnetic element  43  is separated from the first magnetic element  41  and the second magnetic element  42  to a certain extent, the first magnetic element  41  and the second magnetic element  42  also provide the attraction forces to pull back the third magnetic element  43 . That is, when the depressing force F 0  is eliminated, the keycap  20  is driven to be moved away from the base plate  30  in response to the first magnetic force F 1  and the second magnetic force F 2 . Consequently, the magnetic key is returned to the non-depressed state of  FIG. 5A . 
     In some other embodiments, the first magnetic element  41 , the second magnetic element  42  and the third magnetic element  43  that are formed of magnets are thinner or the height H 1  of the first protrusion structure  31  (or the height of the second protrusion structure  32 ) is larger. Consequently, while the keycap  20  is depressed, the contact attraction between the third magnetic element  43  and the first magnetic element  41  and the contact attraction between the third magnetic element  43  and the second magnetic element  42  may be released completely. Similarly, in this design, the influence ranges of the first magnetic force F 1  and the second magnetic force F 2  should be taken into consideration. Consequently, the third magnetic element  43  can be pulled back to the original position where the keycap  20  is not depressed. 
     In accordance with a feature of the present invention, the third magnetic element  43  is magnetically returned to the original position by the first magnetic element  41  and the second magnetic element  42  according to the lateral or horizontal magnetic forces. Please refer to  FIGS. 5A and 5B . When the keycap  20  is not depressed, the first magnetic force F 1  and the second magnetic force F 2  are perpendicular to the normal direction of the base plate  30 . While the keycap  20  is depressed and moved, the first magnetic force F 1  and the second magnetic force F 2  are inclined with respect to the normal direction of the base plate  30 . In other words, the way of magnetically returning the keycap to its original position according to the present invention is not implemented through the magnetic attraction between two vertically stack units along the vertical direction. Consequently, the drawbacks of the conventional technologies (e.g., the increased thickness and volume of the magnetic key) can be effectively solved. 
     It is noted that numerous modifications and alterations may be made while retaining the teachings of the invention. For example, in another embodiment, the base plate  30  is a flat plate without the first protrusion structure  31  and the second protrusion structure  32 . Under this circumstance, the first magnetic element  41  and the second magnetic element  42  are directly fixed on the flat base plate by a hot melt process. For providing sufficient capacity of the accommodation space  10   a , the first magnetic element and the second magnetic element should be high enough. That is, the height of the first magnetic element and the height of the second magnetic element are larger than the thickness of the third magnetic element  43  in order to facilitate returning the keycap to its original position. 
     As mentioned above, the function of returning the keycap to its original position is achieved according to magnetic attraction. The magnetic attraction is generated between the magnets. Alternatively, the magnetic attraction between a magnet and a paramagnetic material is also feasible. For example, the paramagnetic material is a metallic material. 
     In another embodiment, the first magnetic element  41  and the second magnetic element  42  are magnets, and the third magnetic element  43  is made of a paramagnetic material. In another embodiment, the third magnetic element  43  is a magnet, and the first magnetic element  41  and the second magnetic element  42  are made of paramagnetic materials. In another embodiment, the first magnetic element  41  and the second magnetic element  42  are magnets or made of paramagnetic materials, and the third magnetic element  43  comprises plural magnets. Under this circumstance, the plural magnets are arranged in a sheet-like form and unlike poles of these magnets are arranged beside each other. In another embodiment, the third magnetic element  43  is a combination of plural magnets and a paramagnetic material. For example, a metal plate is disposed under the keycap  20  and two magnets are attached on two edges of the metal plate. 
       FIG. 6  is a schematic side cross-sectional view illustrating a magnetic key according to another embodiment of the present invention, in which the magnetic key is in a depressed state. Component parts and elements corresponding to those of the above embodiment are designated by identical numeral references, and detailed descriptions thereof are omitted. In comparison with the above embodiment, the structure of the third magnetic element  43 ′ is distinguished. Moreover, the first magnetic element  41  and the second magnetic element  42  are magnets or made of paramagnetic materials. As shown in  FIG. 6 , the third magnetic element  43 ′ comprises plural magnets  43   a ,  43   b  and  43   c . The magnet  43   c  is arranged between the magnets  43   a  and  43   b . In addition, unlike poles of these magnets  43   a ,  43   b  and  43   c  are arranged beside each other. The magnet  43   a  and the magnet  43   b  are smaller than the magnet  43   c . It is noted that the sizes or thicknesses of these magnets  43   a ,  43   b  and  43   c  may be varied according to the practical requirements. 
     Please refer to  FIG. 6  again. A first magnetic force F 1  is generated between the magnet  43   a  and the first magnetic element  41 . A second magnetic force F 2  is generated between the magnet  43   b  and the second magnetic element  42 . A third magnetic force F 3  is generated between the magnet  43   c  and the magnet  43   a . A fourth magnetic force F 4  is formed between the magnet  43   c  and the magnet  43   b . In case that a depressing force F 0  exerted on the keycap  20  overcomes these magnetic forces F 1 , F 2 , F 3  and F 4 , the keycap  20  can be moved. Since the two magnets  43   a  and  43   b  are independent of the magnet  43   c , these magnets  43   a ,  43   b  and  43   c  are not completely attracted when the magnetic key is in the depressed state. 
     Particularly, while the keycap  20  is depressed, the magnet  43   a  is deflected relative to the first magnetic element  41  and the magnet  43   c , and the magnet  43   b  is deflected relative to the second magnetic element  42  and the magnet  43   c . A top edge L 31  of the magnet  43   c  is connected with a top edge L 11  of the magnet  43   a , and another top edge L 32  of the magnet  43   c  is connected with a top edge L 21  of the magnet  43   b . Moreover, a bottom edge L 12  of the magnet  43   a  is connected with a bottom edge L 4  of the first magnetic element  41 , and a bottom edge L 22  of the magnet  43   b  is connected with a bottom edge L 5  of the second magnetic element  42 . When the depressing force F 0  is eliminated, the keycap  20  is driven to be returned to its original position in response to these magnetic forces. Consequently, the feedback of depressing the keycap  20  is enhanced. 
     Moreover, in case that a more precise machining technology is adopted, the magnetic key is only equipped with a positioning element or the magnetic key is not equipped with any positioning element. In case that only a positioning element is provided, the two positioning elements  21  and  22  in the above embodiments are replaced by a larger positioning element and the sizes and shapes of the recesses  201  and  202  are correspondingly modified. In case that no positioning element is provided, the third magnetic element  43  is directly fixed on the bottom surface of the keycap  20  and the recesses  201  and  202  are omitted. 
     From the above descriptions, the present invention provides a magnetic type keyboard and a magnetic key. Consequently, in comparison with the conventional technologies, the thickness and volume of the magnetic key are effectively reduced. That is, the magnetic type keyboard and the magnetic key can meet the slimness requirement of the applied electronic device. Moreover, the keycap is returned to the original position according to the lateral or horizontal magnetic forces. In comparison with the conventional technologies, the feedback of depressing the magnetic key of the present invention is enhanced. The magnetic type keyboard and the magnetic key can effectively solve the drawbacks of the conventional solve the drawbacks while achieving the purposes of the present invention. 
     While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all modifications and similar structures.