Patent Publication Number: US-2003223186-A1

Title: Notebook computer with low-noise keyboard

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The invention relates to a notebook computer; in particular, a notebook computer with a low-noise keyboard.  
       [0003] 2. Description of the Related Art  
       [0004] Heat dissipation is an important factor in the performance of a notebook computer. The trend towards increased processing speeds has led to an increase in the need for efficient heat dissipation. For instance, the size of the fan can be enlarged so as to enhance the heat dissipation. However, as the size of the fan becomes larger, the noise generated by the fan also increases.  
       [0005]FIG. 1 a  shows a normal notebook computer  100 . The notebook computer  100  comprises a main portion  1  and a display portion  2 . A keyboard  3  is disposed on the main portion  1 , and a fan  16  is disposed in the main portion  1 . The keyboard  3  comprises a plurality of key caps  11 .  
       [0006]FIG. 1 b  is an exploded schematic view showing the keyboard  3 , and FIG. 1 c  is a cross section showing a key assembly of the keyboard  3 . The keyboard  3  comprises a plurality of key caps  11 , a plurality of lift assemblies  12 , an elastic member  13 , a circuit membrane  14 , and a base plate  15 . It is noted that only one key cap  11  and only one lift assembly  12  are shown in FIG. 1 b . In addition, to clarify the structure of the key cap  11  and the lift assembly  12 , their size is slightly magnified.  
       [0007] The base plate  15  is disposed in the main portion  1 , and comprises a plurality of supports  151  and a plurality of hooks  152 .  
       [0008] The circuit membrane  14  is disposed in the main portion  1 , and comprises a plurality of through holes  141 .  
       [0009] The elastic member  13  is disposed in the main portion  1 , and is integrally formed by rubber. The elastic member  13  comprises a body  130 , a plurality of dome-shaped components  131 , a plurality of connecting portions  133 , and a plurality of through holes  132 . The connecting portions  133  connect the dome-shaped components  131 .  
       [0010] The lift assemblies  12  are disposed on the main portion  1 , and each of the lift assemblies  12  comprises a first moving member  121  and a second moving member  122  respectively. The second moving member  122  and the first moving member  121  are pivoted together. In addition, the key caps  11  are disposed on the corresponding lift assemblies  12  respectively.  
       [0011] Furthermore, referring to FIG. 1 b , during the assembly of the keyboard  3 , the elastic member  13  and the circuit membrane  14  are disposed on the base plate  15  so that the supports  151  and the hooks  152  pass through the through holes  141 ,  132 . The lift assemblies  12  are disposed between the base plate  15  and the key caps  11  so that the key caps  11  can move upwardly and downwardly. The first moving member  121  engages with the hooks  152  at the second end  1212 , and engages with the key cap  11  at the first end  1211 . The second moving member  122  engages with the key cap  11  at the first end  1221 , and engages with the supports  151  at the second end  1222 .  
       [0012] When the keyboard  3  is operated, the user presses down the key cap  11  so as to depress the dome-shaped component  131 . Thus, the dome-shaped component  131  is deformed so as to be in contact with the circuit membrane  14 . As a result, the circuit membrane  14  sends a responding signal.  
       [0013] As stated above, there is no special concern about noise when the keyboard is designed. Specifically, the relationship between the fan and the keyboard is not properly studied.  
       [0014] The operation of the keyboard, however, may affect the volume of the noise generated by the fan. Specifically, when the base plate  15  of the keyboard  3  is manufactured, through holes  153  are formed near the supports  151  and the hooks  152  so that the air flow generated by the fan  16  located beneath the base plate  15  can flow to outside the notebook computer  1  through the base plate  15 . Furthermore, as shown in FIG. 1 d , an area P of the base plate  15  is located under the lift assembly  12 , and the through holes  153  are partially located in the area P. It is noted that the area P in FIG. 1 d  simply shows a situation in which the lift assembly  12  is totally laid on the base plate, but does not show the lift assembly  12  inclined relative to the base plate  15 . However, the difference between these two situations does not affect the following description.  
       [0015] Based on the conventional design, since the through holes  153  are located in the area P on the base plate  12 , the movement of the lift assembly  12  may interfere with air flow through the through holes  153  of the base plate  15  when the key cap  11  is operated. As a result, since the key cap  11  may interfere with the air flow passed through the base plate  15 , additional noise is generated when the keyboard  3  is operated.  
       SUMMARY OF THE INVENTION  
       [0016] In order to address the disadvantages of the aforementioned notebook computer, the invention provides a notebook computer with a low-noise keyboard.  
       [0017] Another purpose of this invention is to provide a notebook computer with a reduced number of through holes while maintaining the air flow generated by its fan.  
       [0018] Still another purpose of this invention is to provide a low-noise keyboard that does not interfere with the air flow when it is operated.  
       [0019] Accordingly, the invention provides a notebook computer with a low-noise keyboard. The notebook computer comprises a housing, a base plate and a plurality of lift assemblies. The base plate, having a first area and a second area surrounding the first area, is disposed in the housing. The lift assemblies are disposed on the base plate. The first area is located under the plurality of lift assemblies, and the base plate defines a plurality of through holes located in the second area.  
       [0020] In another preferred embodiment, the invention provides another notebook computer with a low-noise keyboard. The notebook computer comprises a housing, a base plate, a plurality of lift assemblies, and a plurality of key caps. The base plate, having a first area and a second area surrounding the first area, is disposed in the housing. The plurality of lift assemblies are disposed on the base plate, with each of the key caps disposed on the lift assembly respectively. The first area is located under the plurality of key caps, and the base plate defines a plurality of through holes located in the second area.  
       [0021] In another preferred embodiment, the invention provides a low-noise keyboard for a notebook computer. The keyboard comprises a plurality of lift assemblies and a base plate. The base plate supports the plurality of lift assemblies, and includes a first area located under the plurality of lift assemblies and a second area surrounding the first area. The base plate defines a plurality of through holes located in the second area.  
       [0022] In another preferred embodiment, the invention provides another low-noise keyboard for a notebook computer. The keyboard comprises a plurality of lift assemblies, a plurality of key caps, and a base plate. Each of the key caps is disposed on the lift assembly respectively. The base plate supports the plurality of lift assemblies, and includes a first area located under the plurality of key caps and a second area surrounding the first area. The base plate defines a plurality of through holes located in the second area. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0023] The invention is hereinafter described in detail with reference to the accompanying drawings in which:  
     [0024]FIG. 1 a  is a schematic view of a conventional notebook computer;  
     [0025]FIG. 1 b  is an exploded schematic view showing a keyboard in FIG. 1 a;    
     [0026]FIG. 1 c  is a cross section showing a key assembly of the keyboard in FIG. 1 b;    
     [0027]FIG. 1 d  is a schematic view that shows a relationship between a base plate and a lift assembly in FIG. 1 b;    
     [0028]FIG. 2 a  is a schematic view of a notebook computer as disclosed in this invention;  
     [0029]FIG. 2 b  is an exploded schematic view showing a keyboard in FIG. 2 a;    
     [0030]FIG. 2 c  is a schematic view that shows a relationship between a base plate and a lift assembly in FIG. 2 b ; and  
     [0031]FIG. 2 d  is a schematic view that shows a relationship between a base plate and a key cap in FIG. 2 b .  
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0032]FIG. 2 a  shows a notebook computer  200  as disclosed in this invention. The notebook computer  200  comprises a main portion  4  and a display portion  5 . The main portion  4  comprises a housing  8 . A keyboard  6  is disposed on the housing  8  of the main portion  4 , and a fan  7  is disposed in the housing  8  of the main portion  4 . The fan  7  generates an air flow in the housing  8  of the main portion  4 .  
     [0033] Referring to FIG. 2 b , the keyboard  6  comprises a plurality of key caps  21 , a plurality of lift assemblies  22 , an elastic member  23 , a circuit membrane  24 , and a base plate  25 . It is noted that only one key cap  21  and only one lift assembly  22  are shown in FIG. 2 b . In addition, only part of the elastic member  23 , part of the circuit membrane  24 , and part of the base plate  25  are shown in FIG. 2 b . Furthermore, since the key caps  21 , the lift assemblies  22 , the elastic member  23 , and the circuit membrane  24  as disclosed in this invention are similar to those of the conventional keyboard, their detailed description is omitted. In sum, the base plate  25  is disposed in the housing  8 , the lift assemblies  22  are disposed on the base plate  25 , and each of the key caps  21  is disposed on the corresponding lift assembly  22  respectively.  
     [0034] As shown in FIG. 2 c , the base plate  25  defines a plurality of through holes  251  for assisting in dissipating heat in the main portion  4 . In FIG. 2 c , the base plate  21  includes a first area P 1  and a second area P 2  surrounding the first area P 1 . The first area P 1  is located under and corresponding to the lift assembly  22 . The through hole  251  is located in the second area P 2 . Thus, when the lift assembly  22  moves upwardly and downwardly, it does not interfere with the air flow generated by the fan  7 . As a result, the air flow easily passes through the through hole  251 , and the noise due to interference by the keyboard is reduced.  
     [0035] It is noted that the area P 1  in FIG. 2 c  simply shows a situation in which the lift assembly  22  is totally laid on the base plate  25 , but not the lift assembly  22  inclined relative to the base plate  25 . However, the difference between these two situations does not affect the description as disclosed in this invention.  
     [0036] Furthermore, since there is only one lift assembly  22  shown in FIG. 2 c , there is only one first area P 1 . However, in practice, there are a plurality of first areas P 1  corresponding to the number of the lift assemblies  22 .  
     [0037] As stated above, whether the lift assembly  22  moves or not, the air flow generated by the fan  7  can smoothly pass through the through holes  251  so that the noise due to interference by the keyboard can be reduced. Thus, the number of the through holes can be reduced while maintaining the heat-dissipation efficiency. Specifically, since the through holes  251  are still formed on the base plate  25 , the heat in the main portion  4  can be properly dissipated with low noise.  
     [0038] Furthermore, referring to FIG. 2 d , the base plate  21  includes a third area P 3  and a fourth area P 4  surrounding the third area P 3 . The third area P 3  is located under the key cap  21 . The through hole  252  may be located in the fourth area P 4  to reduce the noise as the design concept of the through hole  251 .  
     [0039] While the invention has been particularly shown and described with reference to a preferred embodiment, it will be readily appreciated by those of ordinary skill in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. It is intended that the claims be interpreted to cover the disclosed embodiment, those alternatives which have been discussed above, and all equivalents thereto.