Abstract:
A remote control facilitates the visual indication of the position of an instrument on a touchpad by an external display device. The remote control includes a touchpad that produces a signal responsive to being touched by an instrument, a decoder that decodes the signal and that provides a position signal indicating instrument position on the touchpad, and a transmitter that transmits a coded signal to an external display device. The coded signal facilitates a visual indication of the instrument touchpad position by the external display device.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     Remote controls are well known for controlling distant equipment. Such equipment may include everything from vacuum cleaners to a television receiver.  
         [0002]     If the equipment to be controlled has a display for showing menus or other selectable subject matter, remote controls generally will control an on screen cursor or highlighting with direction keys that move the cursor in a pure X or Y direction. Generally, four such keys are required for left, right, up, and down cursor movement.  
         [0003]     While these prior art arrangements have been somewhat successful, they are cumbersome to use. Also, when time is of the essence, moving a cursor in a first direction and then in a second direction can be time consuming. Moving a cursor directly from point “A” to point “B” is impossible. The present invention addresses these issues.  
       SUMMARY OF THE INVENTION  
       [0004]     In one embodiment of the invention, a remote control comprises a touchpad that produces a signal responsive to being touched by an instrument. The remote control further comprises a decoder that decodes the signal and that provides a position signal indicating instrument position on the touchpad. The remote control further comprises a transmitter that transmits a coded signal to an external display device. The coded signal facilitates a visual indication of the instrument touchpad position by the external display device. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0005]      FIG. 1  is a plan view of a remote control according to one embodiment of the present invention;  
         [0006]      FIG. 2  is a simplified block diagram of a remote control according to an embodiment of the present invention;  
         [0007]      FIG. 3  is a plan view illustrating the use of a remote control according to an embodiment of the present invention; and  
         [0008]      FIG. 4  is a plan view of a display which may be controlled by the remote control of  FIG. 3  according to an embodiment of the present invention. 
     
    
     DESCRIPTION OF THE INVENTION  
       [0009]     In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings, which form a part hereof. The detailed description and drawings illustrate a specific exemplary embodiments by which the invention may be practiced. This embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is understood that other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the present invention. The following detailed description is therefore not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.  
         [0010]      FIG. 1  illustrates a remote control  10  according to an embodiment of the present invention. The remote control  10  includes a housing  12  which houses internal circuitry of the remote control  10 . The remote control also includes a keypad  14  including a plurality of keys  16 . The remote control  10  still further includes, and according to this embodiment of the invention, a touchpad  18  and selection keys  20  and  22 .  
         [0011]     The keypad  14  is provided to function in a manner as well known in the art. Each key of the keypad  14  corresponds to a different function to be commanded of the external equipment to be controlled by the remote control  10 . Preferably, the external equipment includes a display device for displaying menus and other selectable subject matter. When a key of the keypad  14  is depressed, a transmitter within the remote control  10  transmits a coded signal to the distant equipment which receives the coded signal, decodes the coded signal, and actuates the function corresponding to the key depressed. The transmitter of the remote control  10  may be, for example, an infra-red transmitter which utilizes an infra-red LED  24  as a transmission element.  
         [0012]     The touchpad  18  may be provided to the remote control  10  to enable movement of a cursor on the distant equipment display. The touchpad  18  may be of a type well known in the art for moving a cursor along a straight line or other line as determined by the movement of an instrument being placed on or brought into close proximity with the touchpad  18 . The selection keys  20  and  22  may be employed for selecting menu items which correspond to given locations on the touchpad.  
         [0013]     By virtue of the touchpad  18 , according to this embodiment, a cursor may be moved from a first position to a second position on the display screen without having to be moved in a first discreet direction and then in a second discreet direction. Hence, a cursor may be moved along a straight or otherwise continuous path from a first point to a second point by moving an instrument, such as a human finger, along the touchpad  18 .  
         [0014]      FIG. 2  shows a simplified block diagram of the remote control  10  of  FIG. 1 . As will be noted in  FIG. 2 , the keypad  14  and touchpad  18  are coupled to a microprocessor  30 . The microprocessor  30  is coupled to a transmitter  32  which may be, as previously explained, an infra-red transmitter. However, as will be appreciated by those skilled in the art, the transmitter  32  may alternatively be a radio frequency (RF) transmitter.  
         [0015]     The microprocessor  30  may be programmed to provide functionality of a key decoder  34 , a transmitter coder  36 , a touchpad X-Y decoder  38 , and a transmitter touchpad coder  40 .  
         [0016]     The key decoder  34  determines which one of the keys  16  is being depressed. Once the key decoder  34  determines which key is depressed, the transmitter coder  36  then generates a unique pulse code corresponding to the particular depressed key. The generated pulse code signal is then provided to the transmitter  32  which transmits the coded signal to the external device to be controlled.  
         [0017]     Infra-red (IR) signals for use with remote controls are well known. IR remote controls may transmit pulses of IR light to a receiver of the equipment to be controlled. Light emitting diodes may be utilized to transmit the IR light in a frequency range of, for example, 30 kHz-40 Khz. These frequencies are chosen so that other light sources would not interfere with the ability to correctly receive the coded transmitted signals. The coded signals are transmitted in some type of binary code. The binary signal may vary in length for both time and bit length.  
         [0018]     There are generally three different ways that these signals may be coded. This coding is usually based on varying the length of the pulses, varying the length of the spaces between the pulses, or altering the order between spaces or pulses. Accordingly, one form of code produces pulse-width-coded signals wherein the length of the pulses is varied to code the information. For example, if the pulse width is short, it corresponds to a logical 0. If, however, the pulse width is long, it corresponds to a logical 1. Another form of coding provides space-coded signals where the length of the spaces between the pulses is varied to code the information. In this case, if the space width is short, it may correspond to a logical 0. However, if the space width is long, for example, it corresponds to a logical 1. A last form of coding provides shift-coded signals where the order of the pulse space is varied to code the information. In this case, if the space width is short and the pulse width is long, for example, the signal corresponds to a logical 1. However, if the space is long and the pulse is short, the signal may correspond to a logical 0.  
         [0019]     The coded signals are sent according to a known protocol. This protocol may include, for example, information such as the address to the equipment that is using the remote and the command that the equipment must follow. The address is very important because, without it, the signal would be processed by another IR receiver in the area. When a button on the remote is pushed, it sends a string of signals. The first piece of information in the string is called the header. The header usually contains a burst of highs that alerts all of the IR receivers in the area to the string of data being sent. Following the burst of highs is the address to the specific equipment to receive the next piece of data, the command. As long as the button is held down (depressed) the command will continue to repeat over and over. When the button is released, a string of code called the stop is transmitted. As one may guess, the stop tells the equipment to stop its executing the commanded function.  
         [0020]     The touchpad  18  may be of the type which utilizes capacitive position sensing technology. Capacitive position sensing works by sensing an electrical phenomenon called capacitance. Whenever two electrically conductive objects come near to each other without touching, their electric fields interact to form capacitance. The surface of the touchpad  18  may be a grid of conductive metal wires covered by an insulator. The human finger is also an electrical conductor. When the finger is placed on the touchpad, a tiny capacitance forms between the finger and the metal wires in the touchpad. The insulator keeps the finger from actually touching the wires and may be textured to help the finger move smoothly across the surface of the touchpad.  
         [0021]     Electronics, known in the art, can measure the amount of capacitance in each of the wires. When the capacitance increases, the touchpad can tell when the finger is touching it. By determining which wires have the most capacitance, the touchpad can also locate where the finger is on the touchpad to a high degree of accuracy. The sensing electronics may be the touchpad X-Y decoder  38  of the microprocessor  30  or alternatively, may be in an application specific integrated circuit of the touchpad  18 . The application specific integrated circuit or the touchpad X-Y decoder  38  may compute the position of the finger on the touchpad along with the speed in which the finger is moving. The position signal thus produced by the transmitter touchpad coder  40  is thus a coded signal indicative of the position of the finger on the touchpad. The touchpad, touchpad X-Y decoder  38 , and the transmitter touchpad coder  40  may continuously generate position indicative signals as long as the finger or other instrument is moving across the touchpad. The signals thus produced are transmitted by the transmitter  32  for receipt by the distant equipment to be controlled. The signals may be utilized for moving a cursor on a display for performing, for example, menu selection or menu scrolling.  
         [0022]     In view of the foregoing, it can be seen that a position dependent signal may be continuously produced as long as an instrument, such as a finger, is moved along the touchpad  18 . This may be utilized for moving a cursor from a first point to a second point without having to move the cursor in discrete X and Y directions.  
         [0023]      FIG. 3  shows a remote control  50  according to an embodiment of the present invention in use. The remote control includes a housing  52 , a touchpad  54 , a menu selection switch  56 , and an infra-red transmitting element  58 . Here it may be seen that the thumb of a hand is used to swipe the touchpad  54  in the direction of an arrow  60 . In a manner as previously described with respect to  FIG. 2 , the remote control  50  will transmit a continuously changing position dependent coded signal corresponding to, at any one time, the instantaneous position of the thumb on the touchpad  54 .  
         [0024]     As may be seen in  FIG. 4 , a display  70  includes a plurality of selectable menu options, as, for example, menu options  72 ,  74 ,  76 ,  78 , and  80  as well as other menu options not specifically numerated. As will be noted in  FIG. 4 , highlighting on the display  70  is moved from a menu option  76  directly to a menu option  78  along arrow  90  which corresponds to arrow  60  of  FIG. 3 . Hence, menu selection directly from menu option  76  to menu option  78  is rendered possible by employment of the touchpad  54  on the remote control  50  of  FIG. 3 . This is in direct contrast to the discrete X  92  and Y  94  cursor or highlighting of movement previously required by the prior art.  
         [0025]     When the menu option  78  is highlighted by the thumb being over it&#39;s corresponding position on the thumb pad, the selection switch  56  may be depressed to facilitate selection of menu option  78 . Other menu options may be selected in a similar manner.  
         [0026]     While capacitive position sensing touchpads have been generally described herein, other forms of touchpads may also be utilized without departing from the present invention. For example, touchpads utilizing membrane switch technology or resistive sensor technology, may be alternatively employed without departing from the present invention.  
         [0027]     Although the present invention has been described in considerable detail with reference to certain preferred embodiments, other embodiments are possible. Therefore, the spirit or scope of the appended claims should not be limited to the description of the embodiments contained therein. It is intended that the invention resides in the claims.