Abstract:
Disclosed is a scroll key integrally formed with a function selecting switch that selects one of at least two functions. The scroll key comprises a circuit board having a circuit provided for a predetermined function, a vertical rotation switch mounted on the circuit board with a rotation axis thereof being substantially parallel with the circuit board, first and second tact switches mounted on the circuit board in alignment with the rotation axis of the vertical rotation switch, a rotation knob rotating between the vertical rotation switch and the first tact switch in substantially perpendicular relation to the circuit board to rotate the vertical rotation switch and press the first tact switch, and a button mounted on the circuit board to press the second tact switch. Accordingly, a small-sized scroll key can be implemented and assembling of the scroll key is improved.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit under 35 U.S.C. §119(a) of Korean Patent Application No. 2004-16023, entitled “SCROLL KEY HAVING A FUNCTION SELECTING SWITCH” filed Mar. 10, 2004, in the Korean Intellectual Property Office, the entire contents of which are expressly incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a scroll key for performing a scroll function, such as scrolling through menus in portable electronic devices. More particularly, the present invention relates to a scroll key integrally comprising therein a function selecting switch that can scroll menus and also select a function to, for example, scroll other menus.  
         [0004]     2. Description of the Related Art  
         [0005]     Portable electronic devices, such as camcorders, usually comprise a scroll key capable of performing both a scroll function and an enter function. The scroll function is for moving a cursor, on a display screen, for selecting one of various functions of menus displayed on the display screen, and the enter function is for confirming a specific menu choice that the cursor indicates. A function selecting switch may be further adapted to select one from two predetermined functions.  FIG. 1  shows an exemplary switch assembly having the scroll key and the function selecting switch.  
         [0006]     Referring to  FIG. 1 , a conventional switch assembly  1  having a scroll key comprises a circuit board  3  on which a predetermined circuit is formed, a scroll key switch  10  having both the scroll function and the enter function, a tact switch  20 , which is the function selecting switch for conversion of functions to scroll, and a button  21  for pressing the tact switch  20 .  
         [0007]     The scroll key switch  10  comprises a rotation knob  11  rotating about an axis  12  that can be pressed toward the axis  12  by a certain distance, and a body part  13  supporting the rotation of the rotation knob  11 , thereby performing the scroll function. The body part  13  also performs the enter function when the rotation knob  11  is pressed toward the axis  12 . The scroll key switch  10  is mounted on the circuit board  3  in such a manner that the rotation axis  12  is perpendicular to the circuit board  3 , and such that the rotation knob  11  can rotate parallel with the circuit board  3 .  
         [0008]     The tact switch  20  is fixed onto the circuit board  3 , and is typically disposed below the scroll key switch  10 . The button  21  is used to press the tact switch  20 , and is fixed separately on an outer part, such as a casing  40 , of a part where the switch assembly  1  is mounted, such that one end of the button  21  can press the tact switch  20 . A connector  30  is used to connect the switch assembly  1  to a controller (not shown) of the portable electronic device, such as the camcorder.  
         [0009]     Operation of the above-structured switch assembly having the scroll key will be described hereinbelow.  
         [0010]     For the purpose of this discussion, the switch assembly  1  having the scroll key is assumed to be used as a manual focusing key and a menu selection key. The manual focusing key manually controls the focus of a lens in the camcorder, and the menu selection key selects the menu on the screen displayed on the display panel.  
         [0011]     When a user wants manual control of focus of the camcorder lens, the user can press button  21 . The controller perceives the scroll key switch  10  to be the manual focusing key, and the user can then focus the lens by rotating clockwise and counter-clockwise the rotation knob  11  of the scroll key switch  10 .  
         [0012]     If the user wants to select a specific menu in the menu screen displayed on the display panel, the user re-presses button  21 . The controller then perceives the scroll key switch  10  to be the menu selection key for moving the cursor. By rotating the rotation knob  11  of the scroll key switch  10 , the cursor for selecting the menu is moved from one menu to another menu. The moving direction of the cursor is determined by the rotating direction of the rotation knob  11 . After placing the cursor on a desired menu by rotating the rotation knob  11 , if the user presses the rotation knob  11 , the enter function is performed to confirm selection of the desired menu. The button  21  is used for selecting a desired function, and the scroll key switch  10  is used for performing the scroll function with respect to the selected function.  
         [0013]     In the conventional switch assembly  1  having the scroll key, however, the rotation knob  11  of the scroll key switch  10  is mounted parallel with the circuit board  3 . The button  21  for pressing the tact switch  20  is mounted on a separate part. Therefore, miniaturization of the portable electronic device becomes difficult. Furthermore, the separately mounted button  21  for the tact switch  20  is not space-effective, making assembly of the conventional switch assembly more difficult.  
       SUMMARY OF THE INVENTION  
       [0014]     An aspect of the present invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a scroll key having a function selecting switch, which is miniaturized by integrating a rotation knob and a tact switch, in which the rotation knob rotates perpendicularly to a circuit board and the tact switch is in alignment with the rotation knob to select functions.  
         [0015]     Another aspect of the present invention is to provide a scroll key having a function selecting switch, which is space-effective as a portable electronic device and easy to assemble.  
         [0016]     In order to achieve the above-described aspects of the present invention, there is provided a scroll key having a function selecting switch, comprising a circuit board having a circuit provided for a predetermined function, a vertical rotation switch mounted on the circuit board with a rotation axis thereof being substantially parallel with the circuit board, and first and second tact switches mounted on the circuit board in alignment with the rotation axis of the vertical rotation switch. The scroll key according to an embodiment of the present invention further comprises a rotation knob rotatably disposed between the vertical rotation switch and the first tact switch substantially in perpendicular relation to the circuit board to rotate the vertical rotation switch and press the first tact switch, and a button mounted on the circuit board to press the second tact switch. The button has at one side a guide part fixed on the circuit board to guide the rotation and vertical movement of the rotation knob. The guide part of the button is fixed by fusing on the circuit board by using a fixing projection formed at a lower part thereof.  
         [0017]     In order to achieve another aspect of the present invention, there is provided a scroll key having a function selecting switch, comprising a base board, a flexible printed circuit (FPC) placed on the base board and having a circuit of a special function, a vertical rotation switch mounted on the FPC in a manner that a rotation axis thereof is parallel with the base board, a rotation knob of which one end is mounted on the rotation axis of the vertical rotation switch to rotate the vertical rotation switch, and a rotation shaft that protrudes at the opposite end, and a first tact switch mounted on the FPC to be disposed under the rotation shaft of the rotation knob. The scroll key according to another embodiment of the present invention further comprises a holder mounted on the FPC to support the rotation of the rotation shaft above the first tact switch and enable the rotation shaft to press the first tact switch, a second tact switch mounted on the FPC to be aligned with the first tact switch, and a button mounted on the FPC to press the second tact switch.  
         [0018]     The button according to an embodiment of the present invention comprises a fixing part fixed between the holder and the rotation knob on the FPC and a press part extended from the fixing part to press the second tact switch. The holder and the fixing part of the button are fixed on the base board in a manner that fixing projections respectively formed at lower parts thereof penetrate the FPC and the base board and are fused. The vertical rotation switch has a polygonal hole in the center, and the rotation knob has a rotation shaft at one end corresponding to the hole. The hole of the vertical rotation switch has a hexagonal shape.  
         [0019]     The second tact switch according to an embodiment of the present invention is used as the function selecting switch for selecting one from at least two predetermined functions, and the vertical rotation switch performs a scroll function as selected by the second tact switch. The first tact switch performs an enter function for confirming one of menus scrolled by the vertical switch. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
       [0020]     The above aspect and other features of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawing Figures, wherein;  
         [0021]      FIG. 1  shows a conventional switch assembly in which a scroll key comprises a function selecting switch;  
         [0022]      FIG. 2  is a perspective view of a scroll key having a function selecting switch according to an embodiment of the present invention;  
         [0023]      FIG. 3  is an exploded perspective view of the scroll key having the function selecting switch of  FIG. 2 ;  
         [0024]      FIG. 4  is a view of a rotation knob of the scroll key having the function selecting switch of  FIG. 2 ;  
         [0025]      FIG. 5  is a perspective view of a scroll key having a function selecting switch according to another embodiment of the present invention; and  
         [0026]      FIG. 6  is a partial perspective view showing the scroll key of  FIG. 5  having the function selecting switch being mounted in a portable electronic device. 
     
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
       [0027]     Exemplary embodiments of the present invention will now be described in detail with reference to the annexed drawings. In the drawings, the same or similar elements are denoted by the same reference numerals throughout the drawings. In the following description, a detailed description of known functions and configurations incorporated herein have been omitted for conciseness and clarity.  
         [0028]      FIG. 2  is a perspective view of a scroll key having a function selecting switch according to an embodiment of the present invention, and  FIG. 3  is an exploded perspective view of the scroll key having the function selecting switch of  FIG. 2 . Referring to  FIGS. 2 and 3 , the scroll key  100  having a function selecting switch according to an embodiment of the present invention comprises a base board  110 , a flexible printed circuit (FPC)  120 , a vertical rotation switch  130 , a rotation knob  140  for rotating the vertical rotation switch  130 , a first tact switch  150  pressed by the rotation knob  140 , a holder  160  supporting the rotation of the rotation knob  140 , a second tact switch  170  for selecting functions, and a button  180  for pressing the second tact switch  170 .  
         [0029]     The base board  110  serves as a body for the scroll key  100  having a function selecting switch. The base board  110  is made of a sturdy material and comprises a fixing hole for connection with another device, such as a portable electronic device.  
         [0030]     The FPC  120  is a special-function circuit formed on a flexible material. The FPC  120  is assembled on the base board  110 . On the FPC  120 , the vertical rotation switch  130 , the first tact switch  150  and the second tact switch  170  are connected in line.  
         [0031]     The vertical rotation switch  130  for performing a scroll function is attached on the FPC  120  in a manner that a rotation axis thereof is substantially parallel with the surface of the FPC  120 . The vertical rotation switch  130  includes a polygonal hole  131 , preferably a hexagonal hole, in the center for connection with the rotation knob  140 . The vertical rotation switch  130  has the same structure as other general switches having the scroll function, as one skilled in the art can appreciate, and therefore a detailed description thereof will be omitted.  
         [0032]     The rotation knob  140 , as shown in  FIG. 4 , comprises a knob body  141 , and first and second rotation shafts  143  and  145  that protrude on the opposite sides of the knob body  141 . The first shaft  143  formed on one side of the rotation knob  140  is shaped corresponding to the polygonal hole  131  of the vertical rotation switch  130  for connection with the vertical rotation switch  130 . In an embodiment of the present invention, the polygonal hole  131  is preferably shaped as a hexagon, and the shaft  143  has a hexagonal cross-section corresponding to the polygonal hole  131 . The second shaft  145  on the opposite side of the rotation knob  140  has a circular section so that the rotation of the knob body  141  is supported by the holder  160 .  
         [0033]     The first tact switch  150  is mounted on the FPC  120  to be disposed under the shaft  145  of the rotation knob  140 . As the rotation knob  140  is pressed, the first tact switch  150  is pressed by the rotation knob  140 . The holder  160  supports the rotation of the second shaft  145  of the rotation knob  140  above the first tact switch  150  and also supports vertical movement of the shaft  145  as the knob body  141  of the rotation knob  140  is pressed. A fixing projection  165  is formed at a lower portion of the holder  160 . As shown in  FIG. 3 , the holder  160  comprises a leg part  161  to be fixed on the FPC  120 , a guide part  163  supporting the rotation and the vertical movement of the rotation knob  140 . The FPC  120  and the base board  110  respectively have fixing holes  121  corresponding to the fixing projection  165 . By passing the fixing projection  165  of the holder  160  through the fixing hole  121  and fusing the fixing projection  165 , the holder  160  and the FPC  120  are fixed on the base board  110  together.  
         [0034]     The second tact switch  170  is aligned with the rotation knob  140  and the first tact switch  150 , on the FPC  120 , and pressed by the button  180  fixed on the base board  110 . The button  180  comprises a button fixing part  181  to be fixed on the base board  110  and a button press part  182  extended from the top of the button fixing part  181  to press the second tact switch  170 . The button fixing part  181  is interposed between the rotation knob  140  and the leg part  161  of the holder  160  to minimize the size of the scroll key  100 . The button press part  182  comprises a touch surface  183  exposed out of a casing  101  (as shown in  FIG. 6 ) for a user to press, and a pressing projection  184  (shown in  FIG. 2 ) for pressing the second tact switch  170  as the touch surface  183  is pressed. A button fixing projection  185  is formed at a bottom portion of the button fixing part  181 , and a fixing hole  123  is formed on the FPC  120  and the base board  110  corresponding to the button fixing projection  185 . By passing the button fixing projection  185  through the fixing hole  123  formed on the FPC  120 , and the base board  110 , and fusing the button fixing projection  185 , the button  180  and the FPC  120  are fixed on the base board  110  together.  
         [0035]     According to an embodiment of the present invention as structured above, the scroll key  100  that has a function selecting switch can be easily mounted in portable electronic devices by mounting only the base board  110 . The scroll key  100  can be easily mounted because the rotation switch  130 , the first and the second tact switches  150  and  170 , and the button  180  for operating the second tact switch  170  are integrally formed on the base board  110 .  
         [0036]     Referring now to  FIG. 6 , operation of the scroll key having a function selecting switch according to an embodiment of the present invention will now be described. When the touch surface  183  of the button  180 , that is exposed out of the casing  101  of the portable electronic device is pressed, the pressing projection  184  ( FIG. 2 ) moves down, thereby pressing the second tact switch  170 . The second tact switch  170 , being pressed, transmits a predetermined signal to the controller (not shown). The rotation knob  140  can smoothly rotate due to its first and second shafts  143 ,  145  that are respectively supported by the vertical rotation switch  130  and the holder  160 . Also, since the rotation knob  140  is supported at both sides, the size of the knob body  141  of the rotation knob  140  can be selected according to the user&#39;s convenience and the size of the device. When the user presses the rotation knob  140 , the second shaft  145  that is disposed above the first tact switch  150  moves down, thereby pressing the first tact switch  150 . Accordingly, the controller perceives that the enter function has been performed.  
         [0037]     Operation of the scroll key  100  having a function selecting switch, as described above and as mounted in a camcorder and used for manual focusing and a menu selection key, will be described hereinbelow. When the user wants to manually focus the camcorder lens, the user presses the touch surface  183  of the button  180  that is exposed out of the camcorder casing  101 , as shown in  FIG. 6 . Then, the controller perceives the vertical rotation switch  130  to be the manual focusing key that focuses the camcorder lens. Therefore, by rotating the rotation knob  140  that is engaged with the rotation switch  130 , the user can focus the camcorder lens.  
         [0038]     If the user wants to select a specific menu in the menu screen displayed on the display panel, the user re-presses the touch surface  183  of the button  180 . This time, the controller perceives the vertical rotation switch  130  to be the menu selection key for moving the cursor. By rotating the rotation knob  140  engaged with the vertical rotation switch  130 , the cursor for selecting menus is moved from one menu to another menu. The moving direction of the cursor is determined by the rotating direction of the rotation knob  140 . For selection of a certain menu, the user places the cursor on a desired menu by rotating the rotation knob  140  and presses the rotation knob  140 , and therefore, the enter function is performed to confirm the selection of the menu. Thus, the touch one  183  of the button  180  is used to select one of either the manual focusing function or the menu selecting function, and the rotation knob  140  is for performing the scroll function that corresponds to the selected function.  
         [0039]      FIG. 5  is a perspective view of a scroll key having a function selecting switch according to another embodiment of the present invention. Referring to  FIG. 5 , a scroll key  200  comprises a circuit board  210 , the vertical rotation switch  130 , the rotation knob  140  for rotating the vertical rotation switch  130 , the first tact switch  150  (not shown) pressed by the rotation knob  140 , the second tact switch  170  for selecting functions, and a holder button  220  for supporting rotation of the rotation knob  140  and pressing the second tact switch  170 .  
         [0040]     The circuit board  210  is an integration of the base board  110  and the FPC  120  of the previous embodiment described above. The circuit board  210  comprises a general printed circuit board (PCB) of a sturdy material, and a special-functioned circuit formed on the PCB. On the circuit board  210 , the vertical rotation switch  130 , the first and the second tact switches  150  and  170  are mounted in-line. The holder button  220 , which is an integral form of the holder  160  and the button  180  of the previous embodiment, comprises a guide part  221  supporting the rotation and the vertical movement of the rotation knob  140 , a leg part  222  fixing the holder button  220  on the circuit board  210  so that the guide part  221  is disposed above the first tact switch  150 , and a press part  223  formed opposite to the guide part  221  to press the second tact switch  170 . The leg part  222  has a fixing projection at a lower portion thereof such that the holder button  220  can be fusedly mounted on the circuit board  210 . Also, general fastening members, such as a bolt, for fixing an electronic part on a circuit board may be used to fix the holder button  220  on the circuit board  210 . The vertical rotation switch  130 , the rotation knob  140 , the first and the second switches  150  and  170  are the same in the structure and the operation as in the previous embodiment, and therefore, they will not be described in detail.  
         [0041]     Although switches in respectively separate casings have been discussed as examples for the vertical rotation switch  130 , the first tact switch  150  and the second tact switch  170 , each switch can be received in one casing to implement the scroll key having a function selecting switch according to an embodiment of the present invention.  
         [0042]     As can be appreciated from the above description of the present invention, the rotation knob  140  rotates perpendicularly to the circuit board  210 , and the tact switches  150  and  170  for selecting a function are integrally formed with the base board  110  and aligned with the rotation knob  140 . Consequently, the scroll key having a function selecting switch can be miniaturized. Further, according to the embodiments of the present invention, due to the integral structure of the tact switches  150 ,  170  and the buttons for pressing the tact switches, the portable electronic device can be designed with a similar frame and more easily assembled and well assembled.  
         [0043]     While the invention has been shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention, as defined by the appended claims.