Abstract:
A touchless input device has image sensors on the side of a surface to capture the positions and movement of fingers or any visible objects working near or on the surface. Embodiments include touchless data entry keyboards, touchless pointing devices, and touchless screens. It provides better performance, finer resolution, and more clearly defined action space than infrared beam based touchless input devices. In particular, one embodiment merges the space for data entry and the space for cursor movement into one and reduces the number of devices and working space needed by users.

Description:
BACKGROUND 
     Prior Art 
     Today&#39;s touchless input devices, such as touchless keyboards and touchless touch-pad, mainly use the infrared beam detection technology. They basically detect if the infrared beams are blocked or reflected, and use the state change as input signals. 
     The major benefit of such devices for the users are that the forces on fingers can be reduced or even avoided. Such devices are especially needed by those with injured hands or arthritic fingers. 
     However, infrared beam based input devices have some technical limitations that make it difficult to be adopted by a wider user base for practical use. One limitation is that the cross sections of the infrared beams are very small. Users&#39; fingers often miss these spots and result in missed letters and less than desirable performance for many touch-typists. 
     Another issue is that when the size of the keyboard becomes large, the speed of the key response becomes too slow for a high performance keyboard. 
     The main issue with using infrared beams for pointing devices is that it is difficult to achieve the resolution for the pixel densities of today&#39;s display screen. Another issue is that the respond speed of beam action detection can hardly satisfy users&#39; desire today. 
     It is also difficult to satisfy all users with one height of the sensitive areas. The first challenge is the difficulty of controlling the shape and strength of light beams in an extended range. Another challenge is that some people would like a tactile feedback with lower height of interactive space, while some others with nerve diseases on their finger tips want a higher space to avoid touching completely. 
     SUMMARY 
     In accordance with one embodiment, an input device comprises a board with two image sensors on the side, a circuit that connects the image sensors to a microprocessor, and a circuit that enable the microprocessor to communicate with a host computer. 
     ADVANTAGES 
     By using image capture and analysis rather than infrared beam detection, advantages are as follows: each input area can be arbitrarily large within the visible region of the image sensors, that the respond speed can be controlled and improved by using faster processors, that the triggering space can be well defined and adjustable by users with identifiable structures on the board, that the resolution can be controlled by the resolution of the image sensors. Other advantages of one or more aspects will be apparent from a consideration of the drawings and ensuing description. 
    
    
     
       DRAWINGS 
       Figures 
         FIG. 1  shows an embodiment of an input device using 2 image sensors and a transparent board. 
         FIG. 2  illustrates an embodiment for performing the functions of a pointing device. 
         FIG. 3  illustrates an embodiment of a keyboard. 
         FIG. 4  illustrates an embodiment of combining a keyboard and a mouse into one unit. 
     
    
    
     REFERENCE NUMERALS 
     
         
           10 —an image sensor 
           12 —an image sensor 
           14 —a board providing a surface 
           16 —a raised structure on the surface 
           18 —a raised structure on the surface 
           20 —an area on the surface with action space for the left button of a mouse 
           22 —an area on the surface with action space for the middle button of a mouse 
           24 —an area on the surface with action space for the right button of a mouse 
           26 —an area on the surface with action space for the scrolling-up function of the wheel on a mouse 
           28 —an area on the surface with action space for the scrolling-down function of the wheel on a mouse 
           30 —entry point for a finger to move cursor on a keyboard panel 
           32 —toggle spot for switching the action spaces between data entry and cursor movement 
       
    
     DETAILED DESCRIPTION 
     FIG.  1   
     First Embodiment 
       FIG. 1  shows the basic structure of an input device with image sensors  10  and  12  on the side of aboard  14 . The raised structures  16  and  18  at corners of board  14  within the visual field of the image sensors define the height of the region within which an object or finger can trigger input signals. If the heights of structures  16  and  18  are not equal, then the straight connection line between them sweeps horizontally and forms a ceiling surface. 
     The space formed by an area on the board surface and a ceiling surface will be referred to as the action space of the area hereafter. An object or finger can trigger input signals only within this action space. 
     By using two image sensors, the position of a visible object on the surface can be uniquely calculated. This is because the image of an object in the image sensor has a distance in pixels from the center of the image plane of the sensor. The deviation angle of the object from the center of the view field can be obtained from this distance. The position of the object can thus be obtained from the distance between the two image sensors, and the two deviation angles formed by the object with the two image centers using trigonometry. 
     The benefit of using raised structures to define the action space is that the users can change the raised structure and tailor the size and height of the action space to their special needs. 
     Board  14  is transparent here so that a display screen can be placed underneath. Board  14  can also be just a display screen. When a finger moves within an action space that overlays a certain displayed region or elements, input signals are sent to a host computer. 
     The edges of board  14  can also be raised and block the images of outside objects from entering the image sensors. This can save some processing time to improve the performance of the device. 
     Operation— FIG. 1   
     A user can use fingers or any visible object such as a stylus to operate this device to enter signals to a connected computer. The manner of operation is almost the same as a regular tablet computer except that the fingers don&#39;t have to be in contact with board  14 , as long as they enter the action space. 
     The user can tap the action space for a clicking action, slide a finger for moving the displayed image, or perform any other gestures that the host computer can associate a command with. 
     FIG.  2 —An Embodiment as a Pointing Device 
       FIG. 2  illustrates an embodiment to perform all the functions of a mouse. The viewing angle is from the top. Image sensors  10  and  12  are on the side of board  14 . Raised corners  16  and  18  define the height of the action space. On board  14 , areas  20 ,  22 ,  24 ,  26 , and  28  are designated functional areas. 
     Areas  20 ,  22 , and  24  correspond to the left, middle, and right mouse buttons. When a finger enters the action space of one of the areas, a signal of the corresponding mouse button being pressed down is sent to a host computer. When the finger leaves the action space, a signal of the button being released is sent to the host computer. 
     The area  26  and  28  correspond to the scrolling-up and scrolling-down functions of the wheel. When a finger enters the action space, a corresponding wheel-scrolling signal will be sent to the host computer. When the finger leaves the space, a signal of wheel-scrolling stopped is sent to the host computer. 
     When a finger is moving within the action space but outside of the designated functional areas, signals of cursor movement are sent to the host computer. A quick tap on this space can also be considered a left mouse button click. 
     The action space associated with the arrow shaped labels are also for controlling the cursor movement. When a finger is paced in the action space of an area with an arrow label, the cursor will move at a predetermined speed in the direction of the arrow. 
     Operation— FIG. 2   
     The operation this embodiment is almost the same as a regular touch-pad except that the fingers don&#39;t have to be in contact with board  14  when they are within the action space. 
     To trigger a mouse button event, a user moves a finger into the action space of the intended button area to trigger a button-being-pressed signal. The user moves the finger out of the action space to release the button. 
     To move a scroll bar, a user places a finger in the action space of intended wheel scrolling area. The user stops the scrolling by moving the finger out of the action space. 
     A user can move the cursor by moving a finger along the surface within the action space just like using a touch-pad, or by placing a finger in the action space of an arrow label to move the cursor in a specific direction at a specific speed. 
     Thus, this embodiment fully realizes all the functions of a mouse with the advantage of reducing the force and movement of fingers. And the action space is well defined. 
     Today&#39;s image sensors have millions of pixels in their imaging plane, providing enough resolution for most of display screens today. 
     FIG.  3 —An Embodiment as a Data Entry Device 
       FIG. 3  illustrates an embodiment as a keyboard. The viewing angle is from the top. Image sensors  10  and  12  are on the side of a board  14 . Raised corners  16  and  18  define the height of the action space. 
     There are some areas with alphanumeric labels on the board  14 . These areas are designated as key entries corresponding to the labels. When a finger or an object enters one of the action space of theses areas, a key-down signal is sent to a host computer. When the finger or object leaves the action space, a key-up signal is sent to the host computer. 
     Because the height of 16 and 18 are adjustable by users, the height of the action space can be changed by users easily. 
     Operation— FIG. 3   
     A user operates this keypad by moving a finger in and then out of the action space of an area with intended label to enter the label to a connected computer. The force on fingers of pressing down a button of a regular keyboard can be avoided here. 
     FIG.  4 —Embodiment to Combine the Data Entry and Pointing Functions in One Space 
       FIG. 4  illustrates an embodiment for a combination of data entry and pointing devices. The viewing angle is from the top. Image sensors  10  and  12  are on the side of a board  14 . Raised corners  16  and  18  define the height of the action space. 
     There are some areas with labels on board  14 . The areas B 1 , B 2 , and B 3  correspond to the left, middle, and right buttons of a mouse. The areas B 4  and B 5  correspond to the scrolling-up and scrolling-down actions of the wheel. When a finger or stick enters the action spaces of these areas, corresponding signals are sent to a host computer. 
     Other areas are designated as key entries corresponding to their labels. When a finger or an object enters one of the action space of these areas, a key-down signal is sent to a host computer. When the finger or object leaves the space, a key-up signal is sent to the host computer. 
     Area  30  is a designated area for a starting point of moving the cursor. When a finger or object enters into its action space from above, and starts moving within the action space of board  14 , the image sensors and the processor will obtain and convert the data from the movement into cursor movement signals, and then send the signals to the host computer. 
     By overlaying cursor movement space with key entries, users can save some working space and the number of devices. 
     Spot  32  serves as a switch button for the action space of board  14  to work as a keyboard or a pointing device. When a visible object quickly moves in and then out of the action space of spot  32 , the action space of board  14  works as a pointing device as illustrated above. When a visible object enters and then leaves the action space of spot  32  quickly again, the action spaces of data labels toggle back to keyboard entries. 
     Operation— FIG. 4   
     A user can use this embodiment to do the work that usually require two devices, a keypad and a pointing device. A user moves a finger in and then out of the action space of the area with an intended label to enter characters into a connected computer. The user can also do the work of mouse button clicks and wheel scrolling by acting on the corresponding action space as illustrated above. 
     When a user wants to move the cursor while doing data entry, the user enters a finger from above into the action space of area  30 , and move the finger within the action space of board  14  in the direction of intended cursor movement. The cursor stops moving when the finger lifts out of the action space. 
     When a user wants to use a pointing device for a while, the user taps the action space of spot  32  and turn off the data entry functions of the device. Then the device works just like a pointing device as illustrated in  FIG. 2 . When the user wants to use the data entry function again, tapping the action space of spot  32  turns on again the data entry functions of the actions spaces of the areas with character labels. 
     ADVANTAGES 
     From the description above, a number of advantages of some embodiments of my input devices using image sensors on the side of a board become evident: 
     (a) The action space, especially the height, are visibly defined and can be modified by users to meet different users&#39; special needs. 
     (b) The resolution of pointing devices depend on the pixel densities of the image sensors, and can be fine enough for most of the display screens today. 
     (c) The key sizes for data entries can be much larger than the regular sizes of a human finger to satisfy most users&#39; desire without compromising the performance. 
     (d) Any visible objects can be used for input. More flexible than most touch screens. 
     (e) Avoiding force or strain on fingers, and reducing the movement of fingers. 
     (f) Save user some working spaces and the number of devices to work with. 
     CONCLUSION, RAMIFICATIONS, AND SCOPE 
     Accordingly, the reader will see that this type of image sensor based input devices can be used in place of traditional keyboards and mice, as well as touch screens on mobile devices. Furthermore, this type of input devices has the additional advantages in that:
         The area for finger action does not have any electronic elements or circuit board. The device can be much lighter than the traditional ones.   The electronic components are independent of the size of the board. The manufacturing cost is therefore less relevant to the total size.       

     Although the description above contains some specificity, these should not be construed as limiting the scope of the embodiments but as merely providing illustrations of some of the embodiments. For example, the image sensors don&#39;t have to be placed on one side; the image sensors don&#39;t have to face the same direction; there can be more than two image sensors to facilitate faster processing; the raised structures can be of different colors at different places; there can be more labeled areas for various functions; the action space can be predetermined and adjusted purely by software, etc. 
     Thus the scope of the embodiments should be determined by the appended claims and their legal equivalents, rather than by the examples given.