Abstract:
The present invention provides an input device that gives users more flexibility and convenience by allowing them to move the input device in a three-dimensional (3D) space without requiring any flat surface. According to one embodiment of the invention, an input device is provided. The input device comprises a motion detection sensor that generates (3D) motion data associated with (3D) movement of the input device. The device wirelessly transmits the motion data to a computer to cause the computer to derive a distance and direction of the movement of the input device in a two-dimensional plane based on the motion data. The computer then moves a cursor to a corresponding position based on the distance and direction derived. The input device also generates control signals in response to a user&#39;s command to cause the computer to perform a corresponding cursor action, e.g., a double click operation.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The invention relates generally to input devices, and more particularly to contactless input devices.  
         [0002]     Input devices are used to feed data into computers or handheld devices, etc. Computer mice and trackballs are all examples of input devices. A computer mouse is a widely-used input device that controls the movement of the cursor on a display. A trackball is a mouse lying on its back and is popular for portable computers. At present, most conventional input devices suffer from drawbacks. For example, with a conventional mouse, wired or wireless, a user has to operate it on a flat surface, such as a mouse pad. This limits the choices available to the users. For instance, if a user wants to use it during a presentation or a lecture, he or she would have to go to the place where the mouse is located to use it, or control a wireless mouse on a flat surface. This can cause much inconvenience for the user while standing in the middle of the room, giving the presentation or lecture.  
         [0003]     Therefore, there is a need to provide an improved input device that gives users more flexibility and convenience than that offered by conventional input devices.  
       SUMMARY OF THE INVENTION  
       [0004]     The present invention provides an input device that gives users more flexibility and convenience by allowing the users to move the input device in a three-dimensional (3D) space without requiring any flat surface.  
         [0005]     In accordance with one embodiment of the invention, an input device is provided. The input device comprises a motion detection sensor that generates 3D motion data associated with 3D movement of the input device. The device wirelessly transmits the motion data to a computer to cause the computer to derive a distance and direction of the movement of the input device in a two-dimensional plane based on the motion data. The computer then moves a cursor to a corresponding position based on the distance and direction derived. The input device also generates control signals in response to a user&#39;s command to cause the computer to perform a corresponding cursor action, including a left click operation, a right click operation, a double click operation, and a click and drag operation.  
         [0006]     In another embodiment of the invention, the motion data of the input device on first and second axes are used to derive a corresponding position of a cursor, while the motion data on a third axis are used as a basis to perform a corresponding cursor action.  
         [0007]     In this way, the invention provides users with more flexibility and convenience than that offered by conventional input devices.  
         [0008]     Other objects and attainments together with a fuller understanding of the invention will become apparent and appreciated by referring to the following description and claims taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The invention is explained in further detail, and by way of example, with reference to the accompanying drawings wherein:  
         [0010]      FIG. 1  shows an input device connected to a computer according to a first embodiment of the invention;  
         [0011]      FIG. 2  shows an exemplary external design of input device according to the first embodiment of the invention;  
         [0012]      FIG. 3  is a flowchart diagram illustrating a process performed by a computer according to the first embodiment of the invention;  
         [0013]      FIG. 4  shows an input device connected to a computer according to a second embodiment of the invention;  
         [0014]      FIG. 5  shows an exemplary external design of input device according to the second embodiment of the invention; and  
         [0015]      FIG. 6  is a flowchart diagram illustrating a process performed by a computer according to the second embodiment of the invention. 
     
    
       [0016]     Throughout the drawings, the same reference numerals indicate similar or corresponding features or functions.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]      FIG. 1  shows an input device  20  connected to a computer  30  according to a first embodiment of the invention. As illustrated, input device  20  includes a three-dimensional (3D) motion detection sensor  22 , left and right control buttons  24  and  25 , a control circuit  26 , and a communication interface  28 . Computer  30  includes a processor  32 , a memory  34 , a storage device  36 , and a communication interface  38 . For simplicity, other conventional elements are not shown in  FIG. 1 .  
         [0018]     In operation, a user moves input device  20  to point and click, in a 3D space (e.g., in the air), icons on computer  30 . Motion detection sensor  22  detects the 3D motion and communicates the 3D motion data and a sampling rate to computer  30  for moving the cursor on the computer, via a communication interface  28 , such as Bluetooth, Zigbee, IEEE 802.11, infrared. The sampling rate may be a predetermined value set by a manufacturer. From the motion data and the sampling rate received from input device  20 , processor  32  calculates the corresponding 3D coordinates on the x, y and z axes and moves the cursor to a corresponding position on a display of the computer based on the calculated coordinates, or performs a corresponding cursor action.  
         [0019]     Control circuit  26  of input device  20  provides one of two control signals to computer  30  via interface  28  upon receiving a user provided external input via control buttons  24  and  25 . The two control signals represent left and right clicking operations respectively. For example, the user may press left control button  24  to cause control circuit  26  to generate a first control signal for computer  30  to perform an operation corresponding to a left clicking on a conventional mouse.  
         [0020]     In a specific embodiment of the invention, motion detection sensor  22  detects the 3D motion by measuring the acceleration of the movement along the x, y and z axes. As an example, the piezoresistive-type tri-axial accelerating sensor commercially available from Hitachi Metals, Ltd., Tokyo, Japan, may be used as motion detection sensor  22 . This accelerating sensor in the form of an IC chip has the ability to simultaneously detect acceleration in the three axial directions (x, y and z). The senor is highly sensitive and shock resistant and is a very small and thin semiconductor type  3  axial accelerating sensor. More information about this accelerating sensor is available on the following website http://www.hitachimetals.co.jp/e/prod/prod06/p06 — 10.html, the disclosures of which is hereby incorporated by reference.  
         [0021]      FIG. 2  shows an exemplary external design of input device  20  according to the first embodiment of the invention. As shown in  FIG. 2 , input device  20  includes a housing  40  that contains the electronics parts of the device (such as a 3D motion detection sensor IC chip), left and right control buttons  24  and  25 , and a band  42  for mounting input device  20  on the user&#39;s finger. By mounting it on the finger, the user can simply move the finger in a 3D space to point to icons on the computer display and press one of the control buttons for causing corresponding click operation to be performed.  
         [0022]      FIG. 3  is a flowchart diagram illustrating a process  50  performed by computer  30 , according to the first embodiment of the invention. In  FIG. 3 , computer  30  receives the 3D motion data (such as the acceleration data of the movement in the x, y and z directions) and the sampling rate from input device  20  (step  52 ). Based on the information received, processor  32  calculates the corresponding coordinates on the x and y axes for each sampling point using the starting point of the movement as the origin to derive the distance and direction of the input device movement (step  56 ). At this step, each sampling point is in turn used as a reference point for calculating the coordinates of the following sampling point. Processor  32  then moves the cursor along the x and y axes to a corresponding position on the display (step  58 ). Calculation of the distance of the input device movement is continuously performed based on the incoming 3D motion data until processor  32  detects receipt of a control signal (step  62 ). If a control signal is received, it indicates that a control button is pressed. Therefore, a corresponding function is performed (step  68 ). Thereafter, the same process is repeated.  
         [0023]      FIG. 4  shows an input device  80  connected to a computer  30  according to a second embodiment of the invention. Input device  80  is similar to input device  20  in  FIG. 1 , except that it does not include the two control buttons. In this embodiment, the 3D motion data received by computer  30  are used in a different way. Specfically, the movement on the x and y axes are used for deriving the distance and direction of the cursor movement, while the movement on z axis is a determining factor in detecting cursor actions, e.g., click and drag operations, as will be explained in detailed in connection with  FIG. 6 .  
         [0024]      FIG. 5  shows an exemplary external design of input device  80  according to the second embodiment of the invention. As shown in  FIG. 5 , input device  80  includes a stem  84  having a recess  86 , and a 3D motion detection sensor IC chip  88  mounted on stem  84 . The user can simply hold stem  84  at recess  86  with an index finger so as to fix the relative position of input device  80  with respect to the user&#39;s hand. Alternatively, a pointing object may be attached to stem  84  in place of recess  86  as a reference point for use to fix the relative position of input device  80  with respect to the user&#39;s hand. Then the user can freely move input device  80  in a 3D space to point to icons on the computer display. To perform click operations, the user would need to move stem  84  toward a plane perpendicular to the longitudinal direction of the stem, as will be further explained in connection with  FIG. 6 .  
         [0025]      FIG. 6  is a flowchart diagram illustrating a process  100  performed by computer  30  according to the second embodiment of the invention. In  FIG. 6 , computer  30  receives the 3D motion data and the sampling rate from input device  20  (step  102 ), and derives the distance and direction of the input device movement based on the information received (step  106 ), in the same manner as steps  52  and  56  respectively in  FIG. 3 .  
         [0026]     A determination is made as to whether the movement along the z axis is greater than a predetermined absolute value z min  (e.g., 3 cm) (step  112 ). If the determination is negative, it indicates that cursor action is not intended. Hence computer  30  moves the cursor along the x and y axes to a corresponding position in a usual manner, based on the movement of the input device on the x and y axes.  
         [0027]     On the other hand, if the determinaiton is positive at step  112 , it indicates that a cursor action is intended. To distinguish which of the cursor actions, i.e., left click, right click or drag operation, is intended, another determination is made as to whether the movement of the input device along either the x or y axis is greater than the absolute value x min  (e.g., 3 cm) or y min  (e.g., 3 cm), respectively (step  122 ). If neither is the case, it indicates that the input device move along the z-axis only. Thus, the action is interpreted as a simple click, and computer  30  will perform a left click operation (step  126 ).  
         [0028]     On the other hand, if, at step  122 , either the x-axial distance is greater than x min  or the y-axial distance is greater than y min , or both, it indicates that other cursor action is likely to be intended. Then, a determination is made as to whether the time interval between z-axial distance&gt;z min  and x-axial distance&gt;x min  or y-axial distance&gt;y min  is less than t min  (e.g., 200 ms)(step  132 ). If the determination is negative, it indicates that the input device did not move far enough along the x and y axes. Thus, the action is interpreted as a right click, and computer  30  will perform a right click operation (step  136 ). If the determination is positive at step  132 , it indicates that two sequential actions are intended, i.e., a click action followed by a drag action. Thus, computer  30  will perform a dragging operation (step  142 ). In such case, the distances of the input device along the x and y axes are used to determine the drag distance on the display.  
         [0029]     In the above, the invention has been described in connection with a computer. Other computing devices, such as handheld devices, may also be used instead of the computer.  
         [0030]     While the invention has been described in conjunction with specific embodiments, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and scope of the appended claims.