Abstract:
A method for forming a photoelectric switch is disclosed. The method includes providing a granular mold having a first slot and a second slot; filling the first and the second slots with a light-filtering molding material; respectively positioning a transmitter component and a receiver component into the light-filtering molding material(s) in the first and the second slots; and solidifying the light-filtering molding material to fix the transmitter component and the receiver component in the granular mold.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a method for forming a photoelectric component, and more specifically, to a method for forming a photoelectric switch.  
         [0003]     2. Description of the Prior Art  
         [0004]     Please refer to  FIG. 1  and  FIG. 2 .  FIG. 1  is a diagram of individual components of a conventional photoelectric switch  10 .  FIG. 2  is a diagram of the components shown in  FIG. 1  being assembled. As shown in  FIG. 1 , the photoelectric switch  10  comprises a plastic shell  12 , a transmitter component  14  and a receiver component  16 . The transmitter component  14  comprises a transmitting unit  18 , a pair of conducting wires  15   a ,  15   b  and a plastic shell  21 . The receiver component  16  comprises a receiving unit  19 , a pair of conducting wires  17   a ,  17   b  and a plastic shell  22 . The photoelectric switch  10  shown in  FIG. 2  is formed by manually placing the transmitter component  14  and the receiver component  16  into the plastic shell  12 . However, a large amount of time and labor is necessary for the above-mentioned manual assembling process. In addition, the size of the photoelectric switch  10  must not be too small because the above-mentioned assembling process is manually performed. In other words, if the size of the transmitter component  14 , the receiver component  16  or the plastic shell  12  is too small, the assembling process may not be easily carried out manually. Another feature is that the plastic shell  12  of the conventional photoelectric switch  10  is further utilized for providing a masking function of preventing the photoelectric switch  10  from being affected by external light. For this reason, the plastic shell  12  is usually black and cannot be changed to other light colors.  
       SUMMARY OF THE INVENTION  
       [0005]     One of the objectives of the claimed invention is therefore to provide a method for forming a photoelectric switch, in order to solve the above-mentioned problem.  
         [0006]     According to the claimed invention, a method for forming a photoelectric switch is disclosed. The method comprises providing a granular mold having a first slot and a second slot; filling the first and the second slots with a light-filtering molding material(s); respectively positioning a transmitter component and a receiver component into the light-filtering molding material(s) in the first and the second slots; and solidifying the light-filtering molding material to fix the transmitter component and the receiver component in the granular mold.  
         [0007]     The transmitter component and receiver component of the photoelectric switch according to the claimed invention do not have their own shells and are both fixed in a shell of the photoelectric switch by an automatic forming process. Therefore, from the method for forming a photoelectric switch according to the present invention, the forming process of the photoelectric switch can be simplified, and a large amount of photoelectric switches can be automatically produced by the present invention method. The costs of labor and time and the cost of shell material(s) can be significantly reduced. Additionally, the size of the photoelectric switch formed by the automatic assembling process can become smaller. Moreover, the function of filtering out visible light in the photoelectric switch of this invention is provided by the light-filtering molding material (comprising a light-filtering agent), and not by the shell of the photoelectric switch. In this way, by an appropriate selection of a light-filtering agent, the color of the shell of the photoelectric switch according to the present invention is not limited to black.  
         [0008]     These and other objectives 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 that is illustrated in the various figures and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a diagram of individual components of a conventional photoelectric switch.  
         [0010]      FIG. 2  is a diagram of the components shown in  FIG. 1  being assembled.  
         [0011]      FIG. 3  is a diagram of necessary components for forming a photoelectric switch according to the present invention.  
         [0012]      FIG. 4  is an enlarged diagram of a granular mold, a transmitting unit and a receiving unit shown in  FIG. 3 .  
         [0013]      FIG. 5  is a flowchart of forming a photoelectric switch according to the present invention.  
         [0014]      FIG. 6  is a diagram describing a conducting wire frame positioned in a granular mold strip shown in  FIG. 3 .  
         [0015]      FIG. 7  is a diagram of the semi-finished product generated according to a method of the present invention.  
         [0016]      FIG. 8  is a diagram of the photoelectric switch according to the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0017]     Please refer to  FIG. 3  and  FIG. 4 .  FIG. 3  is a diagram of necessary components for forming a photoelectric switch according to the present invention.  FIG. 4  is an enlarged diagram of a granular mold  46 , a transmitting unit  43  and a receiving unit  45  shown in  FIG. 3 . As shown in  FIG. 3 , there are conducting wire frames  32  and  34 , a granular mold strip  36  and a holder  38 . The conducting wire frame  32  comprises a plurality of transmitting units  43  which are already die-bonded and wire-bonded, a plurality of pairs of conducting wires  42   a  and  42   b , and two support bars  50   a  and  50   b . Each pair of conducting wires  42   a  and  42   b  is coupled to a corresponding transmitting unit  43 . A transmitter component  55  is composed of a transmitting unit  43  and a corresponding pair of conducting wires  42   a ,  42   b . In addition, by the positioning function provided by the support bars  50   a  and  50   b  (to be detailed in the following), a distance between each transmitting unit  43  and each pair of conducting wires  42   a ,  42   b  can be fixed.  
         [0018]     The conducting wire frame  34  comprises a plurality of receiving units  45  which are already die-bonded and wire-bonded, a plurality of pairs of conducting wires  44   a  and  44   b , and two support bars  50   c  and  50   d . Each pair of conducting wires  44   a  and  44   b  is coupled to a corresponding receiving unit  45 . A receiver component  56  is composed of a receiving unit  45  and a corresponding pair of conducting wires  44   a ,  44   b . Similarly, by the positioning function provided by the support bars  50   c  and  50   d  (to be detailed in the following), a distance between each receiving unit  45  and each pair of conducting wires  44   a ,  44   b  can be fixed.  
         [0019]     As shown in  FIG. 3 , the granular mold strip  36  comprises a plurality of granular molds  46  and a plurality of brackets  37   a ,  37   b ,  37   c ,  37   d ,  39   a ,  39   b , and  39   c . The holder  38  is utilized for positioning the above-mentioned granular mold strip  36 . Each granular mold  46  comprises two slots  47   a  and  47   b  as shown in  FIG. 4 . It should be noted that in the present embodiment, each granular mold  46  is a plastic one; however, forming the granular mold  46  by other materials is also applicable and is covered by the present invention.  
         [0020]     Please refer to  FIG. 5 .  FIG. 5  is a flowchart of forming a photoelectric switch according to the present invention. An operation of forming a photoelectric switch comprises the following steps:  
         [0021]     Step  200 : Start.  
         [0022]     Step  202 : Position the granular mold strip  36  into the holder  38 .  
         [0023]     Step  204 : Provide a light-filtering molding material and fill the plurality of granular molds  46  of the granular mold strip  36  with the light-filtering molding material.  
         [0024]     Step  206 : Position the conducting wire frames  32 ,  34  in the granular mold strip  36 .  
         [0025]     Step  208 : Heat the light-filtering molding material in the granular molds  46  to speed up solidification of the light-filtering molding material.  
         [0026]     Step  210 : Take the conducting wire frames  32 ,  34  and the solidified light-filtering molding material from the granular mold strip  36  as a semi-finished product.  
         [0027]     Step  212 : Remove the support bars  50   a ,  50   b ,  50   c , and  50   d  from the semi-finished product to form the desired photoelectric switch.  
         [0028]     Step  214 : End.  
         [0029]     A detailed operation flow of the method for forming a photoelectric switch according to the present invention is described as follows. After starting the flow (step  200 ), the granular mold strip  36  is positioned into the holder  38  (step  202 ). Next, the granular molds  46  of the granular mold strip  36  are filled with the light-filtering molding material (step  204 ). In the present embodiment, the light-filtering molding material is a fluid and comprises an epoxy resin and a light-filtering agent to filter out visible light, in order to prevent the transmitting unit  43  and the receiving unit  45  from being affected by visible light. Afterwards, the conducting wire frame  34  is positioned into the granular mold strip  36  filled with the light-filtering molding material. Please refer to  FIG. 6 .  FIG. 6  is a diagram describing the conducting wire frame  34  positioned in the granular mold strip  36 . As shown in  FIG. 4 , each pair of conducting wires  44   a ,  44   b  of the conducting wire frame  34  is partially put into a corresponding slot  47   b  and each receiving unit  45  is entirely put into the corresponding slot  47   b , where the corresponding slot  47   b  is filled with the light-filtering molding material. The conducting wire frame  32  is then positioned in the granular mold strip  36 . In the same manner, as shown in  FIG. 4 , each pair of conducting wires  42   a ,  42   b  of the conducting wire frame  32  is partially put into a corresponding slot  47   a  and each transmitting unit  43  is entirely put into the corresponding slot  47   a , where the corresponding slot  47   a  is filled with the light-filtering molding material (step  206 ). Please note that the support bars  50   a ,  50   b ,  50   c ,  50   d  and the brackets  37   a ,  37   b ,  37   c ,  37   d ,  39   a ,  39   b ,  39   c  are utilized in co-ordination for ensuring that the transmitter components  43  of the conducting wire frame  32  and the receiver components  45  of the conducting wire frame  34  can be appropriately positioned into the corresponding granular molds  46  of the granular mold strip  36 . The support bars  50   a ,  50   b ,  50   c ,  50   d  and the brackets  37   a ,  37   b ,  37   c ,  37   d  are utilized for ensuring each transmitter component  43  and each receiver component  45  are positioned in a corresponding granular mold  46  at an appropriate depth. Please note that the order of inserting the conducting wire frame  32  and the conducting wire frame  34  can be changed.  
         [0030]     Afterwards, the light-filtering molding material in the granular mold strip  36  is heated to speed up the solidification thereof (step  208 ). In other words, the time for forming the photoelectric switches is reduced via this heating procedure. Additionally, after the light-filtering molding material has been solidified, the goal of fixing the transmitting units  43  and the receiving units  45  is achieved. Next, the conducting wire frames  32 ,  34  and the solidified light-filtering molding material are taken from the granular mold strip  36  as a semi-finished product (step  210 ). Please refer to  FIG. 7 .  FIG. 7  is a diagram of the semi-finished product generated according to a method of the present invention. Please note that the above-mentioned solidified light-filtering molding material forms the shells  59  of the plurality of photoelectric switches produced according to the present invention.  
         [0031]     Finally, the above-mentioned semi-finished product is delivered into a forming machine to remove the support bars  50   a ,  50   b ,  50   c ,  50   d  from the semi-finished product. The forming machine cuts the conducting wires  42   a ,  42   b ,  44   a , and  44   b  to obtain appropriate lengths of said conducting wires  42   a ,  42   b ,  44   a , and  44   b . After the support bars  50   a ,  50   b ,  50   c ,  50   d  are removed, the desired photoelectric switches are formed (step  212 ,  214 ). Please refer to  FIG. 8 .  FIG. 8  is a diagram of the photoelectric switch  60  according to the present invention. The photoelectric switch  60  comprises the transmitting unit  43 , the conducting wires  42   a ,  42   b ,  44   a ,  44   b , the receiving unit  45  shown in  FIG. 4  and the shell  59  shown in  FIG. 7 . The transmitter component  55  is composed of the transmitting unit  43  and the pair of conducting wires  42   a ,  42   b , and the receiver component  56  is composed of the receiving unit  45  and the pair of conducting wires  44   a ,  44   b . The shape of the shell  59  and is the same with that of the plastic shell  12  of the photoelectric switch  10  according to the prior art shown in  FIG. 1 .  
         [0032]     As mentioned above, the transmitter component  14  of the conventional photoelectric switch  10  has its own plastic shell  21 , and the receiver component  16  also has its own plastic shell  22 , and the transmitter component  14  and the receiver component  16  are manually installed into the plastic shell  12  of the photoelectric switch  10 . In contrast with the prior art, the transmitter component  55  of the photoelectric switch  60  of this invention does not need additional shells to cover the transmitting unit  43  and to partially cover the pair of conducting wires  42   a ,  42   b . The receiver component  56  of the photoelectric switch  60  also does not need additional shells to cover the receiving unit  45  and to partially cover the pair of conducting wires  44   a ,  44   b . The transmitter component  55  and the receiver component  56  are directly installed in the shell  59  (the shell  59  is formed by solidifying the light-filtering molding material) according to the method of the present invention, which is an automatic process. Therefore, the forming process of the photoelectric switch can be simplified, and a large amount of photoelectric switches can be automatically produced according to the method of the present invention. The costs of labor and time and the cost of shell material(s) can be significantly reduced. Additionally, the size of the photoelectric switch formed by the automatic assembling process can become smaller. Moreover, the function of filtering out visible light is provided by the light-filtering molding material (comprising a light-filtering agent), rather than by the additional external shell of the photoelectric switch. In this way, by an appropriate selection of a light-filtering agent, the color of the shell of the photoelectric switch according to the present invention is not limited to black.  
         [0033]     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.