Patent Publication Number: US-2002011689-A1

Title: Method for manufacturing a keypad

Description:
BACKGROUND OF THE INVENTION  
       [0001] This application incorporates by reference Taiwanese application Ser. No. 89112236, Filed Jun. 21, 2000.  
       [0002] 1. Field of the Invention  
       [0003] The invention relates in general to a method for manufacturing a keypad, and more particularly to a method for manufacturing a keypad with the keys capable of showing the three-dimensional characters.  
       [0004] 2. Description of the Related Art  
       [0005] With the rapid development of the computer and communication technologies, people nowadays living in the global village can communicate easily and conveniently by making a phone call or surfing the net through the computer system or communication system whenever they want, wherever they are. Keypad is an indispensable component of every input device, which has a number of keys represented Arabic numerals (0˜9), Roman numerals (I˜X), English alphabets (A˜Z), various symbols (#, *, +, / . . . ). letters or patterns illustrated some functions. It is easy to record the names, telephone numbers, dates and time schedule or make an operation as a calculator by utilizing the keypad. The keypad can match switches or membranes for using or combine with the conducted rubber for indirectly using to enhance the functions thereof.  
       [0006] The traditional method for manufacturing a keypad illuminated, either the color of the character is darker or lighter than the key body, is to print a character on the top or bottom surface of the key body. The ROC Patent Publication No. 285345 discloses that a character is printed on the bottom of the transparent key by opaque printing ink. Besides, the ROC Patent Publication No. 311229 discloses that the printing ink and paint are first printed on the surface of the transparent key and the light-permeable parts thereof are then scraped. Therefore, the illuminated keypad made by the conventional method does not have the keys capable of showing the three-dimensional characters.  
       SUMMARY OF THE INVENTION  
       [0007] It is therefore an object of the invention to provide a method for manufacturing a keypad, where the key of the keypad has a three-dimensional character. Combined with an illuminant, the transparent key can show the three-dimensional character clearly and distinguishably utilizing the color contrast relation with light.  
       [0008] The invention achieves the above-identified objects by providing a method for manufacturing a keypad, where the key of the keypad has a key body and a three-dimensional character; the manufacturing process includes the female mold corresponding to the key is first made. The first male mold having the three-dimensional character and a second male mold corresponding to the key are then made. The female mold is combined with the first male mold and injected with a first material to form the key body, wherein the reserved space corresponding to the three-dimensional character is within the key body. The second male mold is combined with the female mold having the key body. The second material is then injected into the first reserved space to form the three-dimensional character, wherein the color contrast between the textures of the key body and three-dimensional character enables to display the three-dimensional character shown in the key body.  
       [0009] The invention achieves the above-identified objects by providing another method for manufacturing a keypad, where the key of the keypad has a key body and a three-dimensional character; the manufacturing process includes the first female mold corresponding to the key and the first male mold having three-dimensional character is first made. The first female mold is combined with the first male mold. The first material is injected into the room between the first female mold and the first male mold to form key body, wherein the reserved space corresponding to the three-dimensional character is within the key body. The second male mold and the second female mold corresponding to the three-dimensional character are then made and combined together. The second material is injected into the room between the second male mold and the second female mold to form three-dimensional character. The three-dimensional character is then embedded in the key body to form the key having three-dimensional character. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0010] Other objects, features, and advantages of the invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The description is made with reference to the accompanying drawings in which:  
     [0011]FIG. 1 shows a top view of a keypad according to the preferred embodiment of the invention;  
     [0012]FIG. 2 illustrates a flow chart of a method for manufacturing the keypad of FIG. 1;  
     [0013]FIG. 3A shows a female mold of manufacturing the keypad of FIG. 1;  
     [0014]FIG. 3B shows the first male mold of manufacturing keys with three-dimensional characters of the keypad of FIG. 1;  
     [0015]FIG. 3C shows the second male mold of manufacturing keys with three-dimensional characters of the keypad of FIG. 1;  
     [0016] FIGS.  4 A- 4 D show cross-sectional views of the manufacturing process of the keypad of FIG. 1;  
     [0017]FIG. 4E shows a cross-sectional view of a key structure, which the top of the three-dimensional character connects, the bottom of the cavity;  
     [0018]FIGS. 5A, 5B,  5 D and  5 E shows cross-sectional views of another manufacturing process of the keypad of FIG. 1;  
     [0019]FIG. 5C illustrates a cross-sectional view of the key structure with the reserved space of FIG. 5B;  
     [0020]FIG. 5F shows a first male mold of manufacturing a keypad capable of disposed LED;  
     [0021]FIG. 5G shows a second male mold for manufacturing a keypad capable of disposed LED;  
     [0022]FIG. 6A shows another structural diagram of keys with three-dimensional characters of the keypad of FIG. 1;  
     [0023]FIG. 6B shows a second male mold of manufacturing keys with three-dimensional characters of the keypad of FIG. 6A;  
     [0024] FIGS.  6 C- 6 D shows cross-sectional view of parts of the manufacturing process for making the keypad of FIG. 6A;  
     [0025]FIG. 6E shows a cross-sectional view of the key structure, which the reserved space is filled with the second material of FIG. 6C;  
     [0026]FIG. 7 illustrates a flow chart of another method for manufacturing the keypad of FIG. 1;  
     [0027]FIG. 8A shows a structural cross-sectional view of the second female mold of manufacturing three-dimensional characters;  
     [0028]FIG. 8B shows a structural cross-sectional view of the second male mold of manufacturing three-dimensional characters; and  
     [0029] FIGS.  8 C- 8 F shows another cross-sectional view of parts of the manufacturing process for making the keypad of FIG. 7. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0030] In the following preferred embodiment of the invention, the number (0˜9) keys, # key and * key of the keypad are taken for example. The keys of letters, symbols, numerals or function keys can be also placed instead for applying in different appliances so that the disclosure will be thorough and complete without departing the spirit and scope of this invention.  
     [0031] Referring first to FIG. 1, a top view of a keypad according to the preferred embodiment of the invention is shown. The keypad  100  includes a number of keys  110  such like the number keys 0˜9 and symbol keys #, * which are arranged in arrays with interval. The key includes the key body  111  and the three-dimensional character  112  in the key body  111 , wherein the three-dimensional character  112  is the Arabic numerals 0˜9 or the symbols #, * or the like and is a character with irregular cylinder-shaped.  
     [0032] Referring to FIG. 2, which illustrates a flow chart of a method for manufacturing the keypad according to the preferred embodiment of the invention. The step  20  is first performed, the female mold  300  corresponding to the keys  110  is made. As shown in FIG. 3A, the female mold  300  for making the key bodies  111  is designed with cavities  301  arranged in accordance with the ranking of the keys  110  in FIG. 1. In the step  21 , the first male mold  310  (as shown in FIG. 3B) having three-dimensional characters  311  and the second male mold  330  (as shown in FIG. 3C) corresponding to the keys  110  are made, wherein the three-dimensional characters  311  corresponding to the three-dimensional characters are irregular cylinder-shaped. The second male mold  330  has square platforms  331  and the injection holes  331  thereof, wherein the injection holes  331  are pierced inside the square platforms  331 . The set of the female mold  300 , first male mold  310  and second male mold  330  encompass various possibility of the quantity, size or type of the characters.  
     [0033] Referring next to FIGS.  4 A˜ 4 D, the cross-sectional views of the manufacturing process of the keypad according to the preferred embodiment of the invention is shown. The method proceeds to step  22 , the first male mold  310  is combined with the female mold  300  as shown in FIG. 4A. The step  23  is then performed, the first material is injected in the room between the female mold  300  and the first male mold  310  to form the key body  400  and the reserved space  410  of the corresponding three-dimensional character as shown in FIG. 4B. The first material is injected into the cavity  301  of the female mold  300  from the injection hole  312  of the first male mold  310 . After that, the step  24  is performed, the second male mold  330  is combined with the female mold  300  having key bodies  400  as shown in FIG. 4C, wherein the platforms  331  is tightly embedded in the second male mold  330  and joins the key bodies  400 . In the final step  25 , the second material is injected into the reserved space  410  of the key bodies  400  and the keys  430  having characters  420  made of the second material take shape as shown in FIG. 4D. The second material is injected into the female mold  300  from the injection hole  332  of the second male mold  330 .  
     [0034] The aforementioned first material is a colorless or light-colored transparent texture and the second material is a dark-colored transparent or opaque texture. The feature of the invention is utilizing the color contrast between the first and the second material to display the three-dimensional character  430  shown in the key body  400 . The first material and the second material can be plastic, silica gel or rubber. Besides, in the FIG. 4D, the three-dimensional character  420  can be completely covered inside the key body  400 . For practically implement, however, the top surface of the three-dimensional character  420  can be equal-high relative to the key body  400 . That is to say, the top of the three-dimensional character  311  of the first male mold  310  is connected to the bottom of the cavity  301  of the female mold  300  in the aforementioned manufacturing process as shown in FIG. 4E. The color of the first and the second material in contrast status can be exchanged which means the key body  400  is made of dark-colored transparent or opaque texture and the three-dimensional character  420  is made of colorless or light-colored transparent texture. Combined with an illuminant, the key  430  can show the three-dimensional character  420  clearly and distinguishably while the light goes through the transparent three-dimensional character  420 . It enables the keys  430  to be visible not only in the daytime but also in the nighttime or insufficient light conditions.  
     [0035] Referring to FIG. 5A˜ 5 E, the cross-sectional views of another manufacturing process of the keypad according to the embodiment of the invention are shown. As stated-above, in the step  21 , the first male mold  510  (as shown in FIG. 5F) having three-dimensional characters  511  and seats  512  and the second male mold  530  (as shown in FIG. 5G) having square platforms  531 ,  533  and injection holes  532  are made. The size of the square platform  533  is slightly smaller than that of the seat  512 . The method proceeds to step  22 , the first male mold  510  is combined with the female mold  300  as shown in FIG. 5A. The step  23  is then performed, the first material is injected into the room between the female mold  300  and the first male mold  510  to form the key body  521  and the reserved space  520  as shown in FIG. 5B. The first material is injected into the cavity  301  of the female mold  300  from the injection hole  512  of the first male mold  510 . The reserved space  520  further includes the space A corresponding to the three-dimensional characters  511  and the space B corresponding to the square platform  512  as shown in FIG. 5C. The step  24  is performed, the second male mold  530  is combined with the female mold  300  having key bodies  521  and the square platform  533  is tightly wedged in the space B as shown in FIG. 5D. The set of the female mold  300 , first male mold  510  and second male mold  530  encompass various possibility of the quantity, size or type of the characters. In the step  25 , the second material is injected into the space A of the key body  521  from the injection hole  532  and the key  560  having character  540  made of the second material takes shape as shown in FIG. 5E. The space B is used for disposed the Light Emitting Diode (LED) which provides the light source to display the three-dimensional characters.  
     [0036] Furthermore, the width of the reserved space  410  (i.e. the width of the three-dimensional character  112 ) is merely 1 mm. In order to prevent the second material from failing to be injected into the reserved space  410  and form the three-dimensional character, there is another design of the key structure to overcome the manufacture bottleneck. As shown in FIG. 6A, the key  600  includes a three-dimensional character  601  and a base  602 , wherein the shape of the base is not restricted in the round shape.  
     [0037] Referring to FIGS.  6 C˜ 6 E, the cross-sectional views of the manufacturing process of the keypad of FIG. 6A are shown. As stated-above, in the step  21 , the first male mold  310  and the second male mold  630  (as shown in FIG. 6B) having square platforms  631  are made, wherein the square platform  631  further includes a round cavity  632  and an injection hole. The size of the round cavity  632  is slightly smaller than that of the cavity  301 . The method proceeds to the aforementioned step  22  and step  23 , the female mold  300  with the key body  400  and reserved space  410  is formed. The step  24  is then performed, the second male mold  630  is combined with the female mold  300  having key bodies  400  as shown in FIG. 6C. In the final step  25 , the second material is injected into the reserved space  410  of the key body  400  and the key  560  having a character  640  and a base  641  takes shape as shown in FIG. 6D. The second material is injected into the female mold  300  from the injection hole  633  of the second male mold  630 .  
     [0038] As shown in FIG. 6E, in actually relative size, the second material can be filled into the reserved space  410  gradually through the cavity  632 . With the design of the cavity  632 , it can prevent the second material from failing to be injected into the reserved space  410  due to the inaccurate aiming of the injection hole  633 .  
     [0039] Referring to FIG. 7, a flow chart of another method for manufacturing the keypad according the preferred embodiment of the invention is illustrated. Take the keypad structure of FIG. 1 for example, the procedure of manufacture is as follows: in step  70 , the first female mold  300   a  (the same as the female mold  300 ). The step  71  is performed, the first male mold  310  (as shown in FIG. 4A) with three-dimensional characters  311  is made. In step  72 , the first male mold  310  is combined with the first female mold  300   a.  In step  73 , the first material is injected into the room between the first female mold  300   a  and the first male mold  310  to form the key body  400  and the reserved space  410  as shown in FIG. 4B.  
     [0040] The step  74  is performed, the second female mold  800  and the second male mold  810  corresponding to the three-dimensional characters are made. As shown in FIGS. 8A and 8B, the second female mold  800  includes the cavities  801  capable of containing three-dimensional characters  112  while the second male mold  810  includes the injection holes  802  arranged in accordance with the corresponding keys. The step  75  is then performed, the second female mold  800  is combined with the second male mold  810  as shown in FIG. 8D. In step  76 , the second material is injected into the room between the second female mold  800  and the second male mold  810  to form the three-dimensional characters  812  as shown in  8 E. The second material is injected into the cavity  801  from the injection holes  802  of the male mold  810 . In the final step  77 , the three-dimensional character  812  is embedded in the key body  400  by hand or machines to form the key  820  as shown in FIG. 8F. The first material can be the aforementioned plastic, silica gel or rubber. The second material is solid plastic that the three-dimensional character  812  can be embedded in the key body  400  without damage.  
     [0041] The method of manufacturing a keypad according to the invention overcomes the bottleneck of the conventional techniques. It can directly inject the three-dimensional character into the transparent key body by utilizing the brand-new shaping equipment or embed the three-dimensional character in the transparent key body by hand or machines to produce the illuminated key with three-dimensional character which is bright and dazzling. All the molds for It enables the key thereof to be visible not only in the daytime but also in the nighttime or insufficient light conditions and enhances the attractiveness and practicability of the product with a keypad such like the communication devices, terminal equipment or other appliances.  
     [0042] While the invention has been described by way of example and in terms of the preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment. To the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.