Abstract:
A computer input method is described which comprises providing a plurality of light emitting and receiving devices for detecting one or more touches on a first area of a computer keyboard, coarsely scanning the first area using the plurality of light emitting and receiving devices when no contact on the first area being detected, and densely scanning a second area using a subset of the plurality of light emitting and receiving devices when one or more contact on the first area being detected, the second area being smaller than and situated within the first area.

Description:
BACKGROUND 
     The present invention relates generally to human input devices for computing systems, and, more particularly, to a computer keyboard and mouse combo device. 
     One of the most popular ways to position a cursor on a computer display is to use a mouse, which functions by detecting two dimensional motions relative to its supporting surface. Physically, a mouse comprises an object held under one of a user&#39;s hands, with one or more buttons. Clicking or hovering (stopping movement while the cursor is within the bounds of an area) can select files, programs or actions from a list of names, or (in graphical interfaces) through small images called “icons” and other elements. For example, a text file might be represented by a picture of a paper notebook, and clicking while the cursor hovers over this icon may cause a text editing program to open the file in a window. 
     While conventional mice or touchpad can be highly accurate and capable pointing devices for computers, being a separate device they have some short-comings, such as every time when a computer user wants to move a cursor, he or she has to move his or her hand away from the keyboard and to the mouse, and move the mouse as a physical object. It is not only less efficient but also may cause injury to the hand over an extended period of time of use. 
     On the other hand, a conventional keyboard can only detect pressing of a key thereof, but cannot detect mere touches on the keys. Here, the “touch” refers to a surface of the keyboard being contacted by an object regardless if the key is pressed or not. If the conventional keyboard is a tactile one, the key pressing is a result of the key being depressed. If the conventional keyboard is a surface one, such as Touch Cover in Microsoft Surface, the key pressing is a result of a force being applied on the key. As long as the key remains depressed in tactile keyboard or forced upon in surface keyboard, the key is pressed. 
     As such, what is desired is a computer input device that can perform both keyboard and mouse functions without relying on moving any additional object other than a user&#39;s fingers. 
     SUMMARY 
     A computer input method is described which comprises providing a plurality of light emitting and receiving devices for detecting one or more touches on a first area of a computer keyboard, coarsely scanning the first area using the plurality of light emitting and receiving devices when no contact on the first area being detected, and densely scanning a second area using a subset of the plurality of light emitting and receiving devices when one or more contact on the first area being detected, the second area being smaller than and situated within the first area. 
     The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  illustrates an optical touch sensing system positioned to detect touches on the surface of a keyboard. 
         FIG. 2  illustrates layout arrangement of a keyboard-and-mouse combo device according to an embodiment of the present disclosure. 
         FIG. 3  is a flow-chart diagram illustrating an exemplary operation of a keyboard-and-mouse combo device according to an embodiment of the present disclosure. 
         FIG. 4  illustrates how diagonal scanning can improve accuracy of the touch sensing system shown in  FIG. 2 . 
         FIG. 5  illustrates a scheme of skipping activations of every other light emitting device during a cycle of scanning. 
         FIG. 6  illustrates a scheme of tracking time duration of no-touch on the touch sensing system of  FIG. 2 . 
         FIG. 7  illustrates various options of coarse scanning. 
         FIG. 8  illustrates various options of dense scanning 
     
    
    
     The drawings accompanying and forming part of this specification are included to depict certain aspects of the invention. A clearer conception of the invention, and of the components and operation of systems provided with the invention, will become more readily apparent by referring to the exemplary, and therefore non-limiting, embodiments illustrated in the drawings, wherein like reference numbers (if they occur in more than one view) designate the same elements. The invention may be better understood by reference to one or more of these drawings in combination with the description presented herein. 
     DESCRIPTION 
     The present invention relates to a computer input device utilizing a touch sensing device and a conventional keyboard to provide both keyboard and mouse functions for the computer. The conventional keyboard generally refers to those tactile keyboards with permanent keys. On-screen keyboards are not conventional keyboard at least for the reason that the keys are not permanent. Embodiments of the present invention will be described hereinafter with reference to the attached drawings. 
       FIG. 1  illustrates an optical touch sensing system positioned to detect touches on the surface of a keyboard  100 . The keyboard  100  is a conventional tactile keyboard with a plurality of tactile keys  105 . The optical touch sensing system includes a light emitter  112  and light receiver  118 . The light emitted from the lighter emitter  112  travels above the surface of the keyboard keys  105  to reach the lighter receiver  118 . However when fingers  124  or any other object touches the surface of the keys  105 , the light can be blocked from reaching the light receiver  118 . As a result, the touch can be detected. 
     In embodiments, the light emitter  112  is a light emitting diode (LED) capable of emitting infra-red light; and the light receiver  118  is also a LED capable of receiving infra-red light. 
       FIG. 2  illustrates layout arrangement of a keyboard-and-mouse combo device according to an embodiment of the present disclosure. A plurality of LED emitters X 212 [0:20] and a plurality of LED receivers X 218 [0:20] are disposed along a top edge and a bottom edge, respectively, of the keyboard keys  105 . A plurality of LED emitters Y 212 [0:5] and a plurality of LED receivers Y 218 [0:5] are disposed along a left edge and a right edge, respective, of the keyboard keys  105 . When unblocked, light emitted from the LED emitters X 212 [0:20] can be received by the LED receivers X 218 [0:20], and light emitted from the LED emitters Y 212 [0:5] can be received by the LED receivers Y 218 [0:5]. When an object, such as a finger, comes into contact with the surface area  220  of the keys  105 , certain light beams in both the X direction and Y direction will be blocked, hence the touch coordinates can be detected. 
     As shown in  FIG. 2 , the LED emitters X 212 [5:15] and the corresponding LED receivers X 218 [5:15] are placed more closer to each other, therefore, the surface area  230  covered by these emitter-and-receiver pairs has high resolution in detecting the touch on the surface of the keys  105 . In other embodiments, the high resolution area  230  may be shifted to either left or right from the center of the keyboard  105 . There may even be two of such high resolution area  230  arrange, one on the left and the other on the right of the keyboard  105 . 
     As shown in  FIG. 2 , an orthogonal light beam  242  and a diagonal light beam  245  are emitted from the LED emitter Y 212 [ 2 ], and received by the LED receivers Y 218 [ 2 ] and Y 218 [ 5 ], respective. Combining the orthogonal and diagonal detections may also enhance detection resolution. Apparently, the orthogonal and diagonal detection and combination can also be applied to the X direction. 
       FIG. 3  is a flow-chart diagram illustrating an exemplary operation of a keyboard-and-mouse combo device according to an embodiment of the present disclosure. In the beginning, the keyboard-and-mouse combo device coarsely scan the larger area  220  as shown in  FIG. 2  by sequentially activating the LED emitter-and-receiving pairs in step  310 . In one embodiment, the coarse scanning is represented by detecting only orthogonal light beams, such as light beam  242  in  FIG. 2 . In another embodiment, the coarse scanning is represented by activating every other LED emitter-and-receiver pair, particularly in the high resolution area  230  in  FIG. 2 . For instance, after activating LED emitter X 212 [ 5 ] and LED receiver X 218 [ 5 ], LED emitter X 212 [ 7 ] and LED receiver X 218 [ 7 ] are subsequently activated. In other embodiments, the coarse scanning is represented by slowing down the scanning pace, i.e., the time interval between two sequential LED activations is relatively longer than normal. 
     Referring to  FIG. 3  again, the scanning detects if there is one or more touches on the keyboard surface  105  in step  320 . If a touch is detected, the keyboard-and-mouse combo device will start to densely scan the high resolution area  230  as shown in  FIG. 2  in step  330 . In one embodiment, the dense scanning is represented by sequentially activating every LED emitter-and-receiver pairs corresponding to the high resolution area  230 . In another embodiment, the dense scanning is represented by combining both orthogonal and diagonal light beams in detection. In other embodiments, the scanning pace may be faster than normal. 
     In embodiments, while densely scanning the high resolution area  230 , the keyboard-and-mouse combo device still performs coarse scanning on the area  220  that is outside of the high resolution area  230 . While dense scanning may result in higher resolution and more dynamic touch coordinate detection, it would be desirable to reduce power consumption by the keyboard-and-mouse combo device whenever possible. Therefore, in step  340 , when the keyboard  105  experiences no touch for a predetermined period of time, the operation will be directed back to coarse scanning. Otherwise the operation remains in dense scanning. In embodiments, the predetermined period of time is adjustable by a computer user, just like the time to enter a screen saver of a computer display is adjustable by a computer user. 
       FIG. 4  illustrates how diagonal scanning can improve accuracy of the touch sensing system shown in  FIG. 2 . For illustration purpose, two light emitters  412 ,  415 , and two light receivers  422 ,  425  of the touch sensing system is shown in  FIG. 4 . Light beams  432  and  435  are orthogonal light beams between the light emitters  412 ,  415  and the light receivers  422 ,  425 , respectively. Light beam  438  is a diagonal light beam between the light emitter  415  and the light receiver  422 . A touching object  445  has an edge situated somewhere between the orthogonal light beams  432  and  435 , and blocks the diagonal beam  438 . 
     As shown in  FIG. 4 , if a scanning utilizing only the orthogonal light beams  432  and  435 , the location of the edge of the object  445  can only be recognized as corresponding to either the light beam  432  or the light beam  435 , and not locations in between the orthogonal light beams  432  and  435 . If a scanning utilizing both the orthogonal and the diagonal light beams  432 ,  435  and  438 , the location of the touching object  445  as shown in  FIG. 4  can be recognized with the assistance of the diagonal light beam  438 . Therefore, adding diagonal light beam detection can increase accuracy of the touch sensing system without physically increase the density of light emitter-receiver pairs. However, the location of the touching object  445  has to be calculated from the distance between the light emitter-receiver pair and the pitch of the activated light receivers. 
       FIG. 5  illustrates a scheme of skipping activations of every other light emitting device during a cycle of scanning. Light emitters E 1 , E 2 , . . . E 5  are sequentially placed in a line. A pulse generator (not shown) periodically generates a pulse with a time interval (T). The pulse is sequentially supplied to light emitters E 1 , E 3  and E 5 , and light emitter E 2  and E 4  are skipped. If the pulse interval time is fixed, the scanning cycle time can be reduced by half for skipping every other light emitter. On the other time, the scanning cycle time instead can be fixed, while the pulse interval time is increased, so that power consumption by the touch sensing system can be reduced. However, by skipping activation of every other light emitting device during a scanning cycle, the accuracy of the touch sensing system will be reduced. Therefore, such scanning method should only be used when no touch have been detected. 
       FIG. 6  illustrates a scheme of tracking time duration of no-touch on the touch sensing system of  FIG. 2 . During a particular scanning cycle between time t 0  to time t 1 , a light receiver Ri detects emitted light being blocked at time t 0 . Then if no light receiver detects any emitted light being blocked during an immediately subsequent scanning cycle after time t 1 , a timer (not shown) will be triggered at the end of the immediately subsequent scanning cycle. In embodiments, the timer has a predetermined count-down value (T), and after the timer counts to zero, the touch sensing system will be automatically switched from dense scanning to coarse scanning for lowering power consumption, as there is no need for detection accuracy during the no touch period. Such count-down value (T) can be exemplarily set at 10 seconds and can be reset by a user to another value. Apparently, a count-up timer can function in the same way as a count-down timer. In other embodiments, the timer can be replaced with a cycle counter. Because the time duration of each scanning cycle is known, counting scanning cycles has the same effect as the aforementioned timer. 
     Referring to  FIG. 6  again, if a blocked emitted light is detected by a light receiver Rj at time ti, the touch sensing system will be immediately switched to dense scanning mode if it previously operates in coarse scanning mode. 
       FIG. 7  illustrates various options of coarse scanning  310 . One option is to utilize only orthogonal light beams for touch detection in item  712 , so that fewer number of light receivers will be activated, and the diagonal light beam calculations will be put to rest. Another option, shown in item  722 , is to skip activating every other light emitters for a scanning cycle as illustrated in  FIG. 5 . Yet, another option, shown in item  732 , is to reduce the scanning frequency, i.e., every scanning cycle takes longer time. The above options for coarse scanning can be used individually or in combination. 
       FIG. 8  illustrates various options of dense scanning  330 . One option is to utilize both orthogonal and diagonal light beams for touch detection in item  812 , so that the touch detection can be more accurate. Another option, shown in item  822 , is to use every light emitter during a scanning cycle. Yet, another option, shown in item  832 , is to increase the scanning frequency, i.e., making every scanning cycle take shorter time. The above options for dense scanning can be used individually or in combination. 
     The above illustration provides many different embodiments or embodiments for implementing different features of the invention. Specific embodiments of components and processes are described to help clarify the invention. These are, of course, merely embodiments and are not intended to limit the invention from that described in the claims. 
     Although the invention is illustrated and described herein as embodied in one or more specific examples, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention, as set forth in the following claims.