Abstract:
A multi-function touchpad has a first button located at substantially a center of the touchpad and a second button at substantially an edge of the touchpad. When the first button is pressed, if the second button is also pressed, the touchpad triggers the function in response to the first button and ignores the pressing of the second button.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention is related generally to a touchpad and, more particularly, to a multi-function touchpad.  
       BACKGROUND OF THE INVENTION  
       [0002]     Touchpad has been widely used in various electronic products to replace the conventional input apparatus due to its simple construction, light weight and low-cost. Currently, there are two types of touchpads, one for one-dimensional mode and the other for two-dimensional mode.  FIGS. 1 and 2  show two typical sensors  100  for two-dimensional touchpad, which have a plurality of horizontal traces  102  and vertical traces  104  arranged in a matrix manner. When a finger touches on the two-dimensional touchpad  100 , the traces  102  and  104  at the touched position will produce a signal to provide the information of the coordinate of the touched position for a host connected with the two-dimensional touchpad  100 . When a finger moves on the two-dimensional touchpad  100 , the host could determine the moving direction according to the coordinate difference in the movement and respond to this operation.  
         [0003]     However, when a user intends to slide his finger in horizontal or vertical direction, a two-dimensional touchpad may not determine the operation precisely. As shown in  FIG. 3  for example, when a user intends to scroll a scroll bar on a window rightward, his finger  106  will move from left to right on the two-dimensional touchpad  105 , while during the movement, the finger  106  might deviate upward or downward and thus cause an upward or a downward scrolling along with the rightward scrolling.  
         [0004]     On the other hand, U.S. Pat. Publication No. 2004/0252109 discloses a one-dimensional touchpad sensor, which may produce a corresponding response, such as up/down, left/right, and add/subtract, by sensing the movement of a finger as rotating clockwise or counterclockwise on the touchpad. Thus an irregular rotating degree will not affect the judgment to the operation. Though this one-dimensional touchpad is capable of determining the direction as plus or minus exactly, it cannot provide multiple functions such as handwriting recognition, as a two-dimensional touchpad does. If any extra function is required, an extra button or other input device has to be added and thus increases the cost of the hardware.  
         [0005]      FIGS. 4 and 5  are the front and rear views of an input apparatus  108  currently used on ipod, which employs a one-dimensional sensor  110  as disclosed in U.S. Pat. Publication No. 2004/0252109. When a finger rotates clockwise or counterclockwise on the circular sensor  110 , it is capable of scrolling the list or to adjust the volume. There are further buttons  112  and  114  at the top, bottom, left, right, and center positions of the sensor  110  to provide extra functions, such as start/stop, forward/backward, list and enter. Since the sensor  110  has a circular shape, the central button  112  is alone and could not be as a whole with the sensor  110  in hardware. As shown in  FIG. 6 , if the sensor  110  is made of a complete circular body, when the center button  112  is pressed, the sensor  110  will have a concave due to the pressure of the finger, and if the pressed position has a departure from the center position, there is a good possibility that the button  114  is pressed by mistake, and thus causes a wrong response.  
         [0006]     Thus, it is desired a multi-function touchpad supporting one-dimensional and two-dimensional operational modes and integrated with buttons as a whole.  
       SUMMARY OF THE INVENTION  
       [0007]     Accordingly, an object of the present invention is to provide a multi-function touchpad which is capable of supporting one-dimensional and two-dimensional operational modes and integrated with buttons as a monocoque.  
         [0008]     In a multi-function touchpad according to the present invention, a touch-sense apparatus is capable of supporting one-dimensional and two-dimensional operational modes such that the touchpad can be operated under the one-dimensional or the two-dimensional operational modes, a first button located at substantially the center of the touchpad, and at least one second button located at substantially the edge of the touchpad. When the first button is sensed to be pressed, and the at least one second button is also sensed to be pressed, the touchpad triggers the function in response to the first button and ignores the pressed one or ones of the at least one second button. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0009]     These and other objects, features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings, in which:  
         [0010]      FIGS. 1 and 2  show two typical sensors for two-dimensional touchpad;  
         [0011]      FIG. 3  shows a diagram of a finger moving on a two-dimensional touchpad;  
         [0012]      FIGS. 4 and 5  are the front and rear views of an input apparatus currently used on iPod;  
         [0013]      FIG. 6  shows a cross-sectional view of the input apparatus shown in  FIG. 5  when its center button is pressed;  
         [0014]      FIG. 7  shows a block diagram of a first embodiment according to the present invention;  
         [0015]      FIG. 8  shows a front view of a touch-sense apparatus according to the present invention;  
         [0016]      FIG. 9  shows an operational illustration of a touch-sense apparatus according to the present invention in one-dimensional operational mode;  
         [0017]      FIG. 10  shows a block diagram of a second embodiment according to the present invention;  
         [0018]      FIG. 11  is a rear view of the sensor of a touchpad according to the present invention;  
         [0019]      FIG. 12  shows a timing diagram for the buttons shown in  FIG. 11 ; and  
         [0020]      FIGS. 13 and 14  show the front and rear views of a sensor in another embodiment according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]      FIG. 7  is a block diagram of a touch-sense apparatus  200  capable of supporting one-dimensional and the two-dimensional operational modes, and  FIG. 8  is an operation illustration. When a finger  214  touches the panel  212  of the touchpad, in the touch-sense apparatus  200 , a sensor  202  detects the position of the finger  214  on the panel  212  and thereby produces a two-dimensional signal Sd to a two-dimensional coordinate processor  204  to generate a two-dimensional coordinate (x,y). Under the two-dimensional operational modes, the two-dimensional coordinate (x,y) is directly sent to a host  206 , and thus the host  206  obtains the current position of the finger  214 . When the finger  214  further moves on the panel  212 , the two-dimensional coordinate processor  204  sends the coordinate difference to the host  206 , such that a corresponding response is generated in response to the movement of the finger  214 . Under the one-dimensional operational mode, the two-dimensional coordinate (x,y) is transferred to a coordinate transformer  208  to transfer to a one-dimensional signal Ss, and a one-dimensional coordinate processor  210  generates a one-dimensional coordinate θ according to the one-dimensional signal Ss to the host  206 . In this embodiment, the one-dimensional coordinate θ is the angle between the finger  214  and the centerline  215 . As shown in  FIG. 9 , when the finger  214  further moves on the panel  212 , the one-dimensional coordinate θ is changed accordingly, and the one-dimensional coordinate processor  210  sends the coordinate difference to the host  206 , such that it can determine the movement of the finger  214  as clockwise or counterclockwise and generate a corresponding response. The touchpad of the present invention supports the one-dimensional and the two-dimensional operational modes, and thus has the advantages of both therefrom. Users can choose the one-dimensional or the two-dimensional operational mode according to their needs.  
         [0022]     The control method for mode switch can be achieved by defining the position of the finger  214  on the panel  212  as the one-dimensional or the two-dimensional operational mode. For example, as shown in  FIG. 8 , the panel  212  is defined with an exterior region  216  and an interior region  218 . When the finger  214  falls on a position within the exterior region  216 , the touch-sense apparatus  200  enters the one-dimensional operational mode. When the finger  214  falls on a position within the interior region  218 , the touch-sense apparatus  200  enters the two-dimensional operational mode. In this embodiment, because the exterior region  216  and the interior region  218  are concentric circles, the center of the circle can be set as the original point ( 0 , 0 ) of a coordinate system. If the coordinate of the finger  214  on the panel  212  is (x,y), the distance between the finger  214  and the center of the circle (0,0) can be obtained according to the radius equation
 
 R=√{square root over (x 2 +y 2 )}   [Eq-1]
 
 Furthermore, if the radius of the interior region  218  is r, it is then determined that, when R is greater than r, the finger  214  falls in the exterior region  216 , and when R is less than r, the finger  214  falls in the interior region  218 . In some other embodiments, the panel  212  is defined with two or more regions. In yet some other embodiments, the shapes of the defined regions on the panel  212  are irregular. The shape of the panel  212  is not limited to circle, and other geometric shapes such as rectangular, triangle and other irregular shapes are also applicable. 
 
         [0023]     The number of the fingers on the panel  212  may be also used to switch between the one-dimensional and two-dimensional operational modes. For example, when there is only one finger falling on the panel  212 , the touch-sense apparatus  200  will switch to operate under the two-dimensional operational mode, and when there are two fingers falling on the panel  212 , the touch-sense apparatus  200  will switch to operate under the one-dimensional operational mode. Otherwise, other gesture may also be used to switch between the operational modes. For example, a double click of the finger on the panel  212  is to switch the operational mode.  
         [0024]      FIG. 10  shows a block diagram of another touch-sense apparatus  200  to support one-dimensional and two-dimensional operational modes. The elements in this embodiment are the same as in  FIG. 7 , while the signal Sd produced by the sensor  202  is directly connected to the coordinate transformer  208 . When the finger  214  touches the panel  212  of the touch-sense apparatus  200 , the sensor  202  detects the position of the finger  214  to produce the two-dimensional signal Sd to both the two-dimensional coordinate processor  204  and the coordinate transformer  208 . The two-dimensional coordinate processor  204  generates the two-dimensional coordinate (x,y) to the host  206  according to the two-dimensional signal Sd, and the coordinate transformer  208  transforms the two-dimensional signal Sd to the one-dimensional signal Ss to the one-dimensional coordinate processor  210  to generate the one-dimensional coordinate θ to the host  206 . The host  206  may automatically determine which coordinate, the two-dimensional coordinate (x,y) or the one-dimensional coordinate θ, is used.  
         [0025]      FIG. 11  is a rear illustration of the sensor  202  of a touchpad according to the present invention, which has 5 buttons  2022  and  2024  on the sensor  202 . The buttons  2022  are disposed on the up, down, left and right edges of the sensor  202 , and the button  2024  is located on the center of the sensor  202 . When any one of the buttons  2022  is pressed by mistake due to the departure from the center position during pressing the center button  2024 , a software or a firmware algorithm can be used to trigger the function in response to the button  2024  and to ignore the pressing of the button  2022 .  FIG. 12  shows a timing diagram for the buttons  2022  and  2024  in  FIG. 11 , in which waveform  300  represents the signal produced by pressing the button  2024  and waveform  302  represents signal produced by pressing the button  2022 . When a user presses the center button  2024 , which will trigger the signal  300  to transit from logical low to logical high, if the pressed position deviates from the center so as to press the button  2022 , the signal  302  will be also triggered to transit from logical low to logical high. In this case, a predetermined algorithm will perform the function in response to the button  2024  because the signal  300  is triggered first, and the pressing of the button  2022  will be ignored to prevent unexpected operations.  
         [0026]     Since an algorithm is used to prevent the wrong operation due to the wrong pressing of the button  2022  resulted from the concave of the sensor  202  when the center button  2024  is pressed, the touchpad being as a whole is achieved after integrating the buttons  2022  and  2024 .  
         [0027]      FIGS. 13 and 14  show another embodiment of the button integration according to the present invention, in which  FIG. 13  shows the front view of the sensor  202  and  FIG. 14  shows the rear view of the sensor  202 . Referring to  FIGS. 13 and 14 , there are horizontal traces  102  and vertical traces  104  on the front side of the sensor  202  with the button  2024  located at the center, and  4  buttons  2022  located at the four edges of the top, down, left and right positions on the back side of the sensor  202 . In this embodiment, since the center button  2024  is located at a different surface from that of the other 4 buttons  2022 , when pressing the center button  2024 , a departure of the pressed position from the center will not trigger the button  2022  by mistake.  
         [0028]     While the present invention has been described in conjunction with preferred embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and scope thereof as set forth in the appended claims.