Abstract:
A keyboard where a light beam is reflected off a finger to detect a keyboard key location sent to a PC or other device that can be used in bright sunlight and total darkness. The keyboard has a planar top surface with no openings or bacteria harbors.

Description:
CROSS-REFERENCES TO RELATED APPLICATION 
     This application is a continuation-in-part (CIP)application of the patent application having U.S. Ser. No. 13/183,605 filed on Jul. 15, 2011. The complete contents of the above-identified patent application being herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a standalone input device or keyboard with a planar top surface with no openings or cracks to a personal computer (PC), control panels for operating equipment, and data input in rugged environments where an internal light beam is emitted out through an optical opening into bright sunlight ambient or total darkness, when a finger is present the finger encompasses the opening blocking out the ambient influence on a detector, the emitter is turned on reflecting the emitted unabated beam off the finger to a detector indicating a finger is present. 
     2. Description of the Prior Art 
     Optical keyboards some use techniques to reduce the ambient effect on finger detection but when used in bright sunlight where bright sunlight saturates the photodiodes nothing stops this saturation unless under an awning or the like, and in total darkness where the user cannot see the key indicia, or lack a planer top surface to be easily cleaned in industrial, atomic and medical environments, some of which that try follow hereto. 
     U.S. Pat. No. 6,175,679 Veligdan et al shows a keyboard with stacked waveguides to detect a finger. 
     U.S. Pat. No. 4,629,884 Bergstom with a radiation propagating prism to detect a finger. 
     U.S. Pat. No. 4,701,747 Isterwood shows a keyboard that has a light beam from a LED that reflects the light beam to a photodiode when a finger is present with a noise and ambient electronic rejection technique. 
     U.S. Pat. Nos. 5,378,069, 5,577,848, 5,605,406, 5,707,160, 5,785,439, Bowen shows keyboards that detects an users finger by blocking an X and Y optical beam. 
     SUMMARY OF THE INVENTION 
     The invention being a keyboard where a light beam is reflected off a finger to detect a keyboard key location and can be used in bright sunlight and total darkness with no openings or cracks in the keyboard top surface to harbor bacteria. 
     It is therefor the primary objective of this invention in environments where an internal light beam is emitted out through a opening into an ambient where in high ambient when a finger is present the finger encompasses the opening blocking out the ambient influence on a detector and reflecting the unabated beam from the finger to a detector indicating a finger is present. This small opening is about the size of the finger print area of a users finger, or about ten mm in diameter. 
     A further object of the invention is to have a LED of different wave length to the finger detection emitter and photo detection diode to emit a visible light beam to show the key indicia in dark environments to direct the user to a key location. 
     A further object of this invention is to have keyboard top surface to be a planar one piece top surface with no opening or cracks, for atomic contaminates, medical contaminates or fluids or other contaminates that cannot be easily cleaned, this is very advantageous because the size of nuclear molecules are so small even the smallest crack or even a decal on the top surface can harbor nuclear contaminates or bacteria. 
     A further object of this invention is to have calibration where the dark count from the photo detector is stored and finger detection scanning is not started until this calibration level or derivative thereof is reached. 
     A further object of this invention is to detect changing ambient light to automatically change the output intensity of the key indicia LED output so the key indicia is always readable by the user. 
     A further object of this invention to have the threshold of the photo detector variable to ambient changing lighting to scan for a finger prior reaching the calibration level. 
     A further object of the invention is to have no finger detection moving parts facilitating long operational life. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other objects, aspects and advantages will be better understood from the following detailed description of the invention with reference to the drawings, in which: 
         FIG. 1  shows a finger placed on a key location with printed or molded key indicia of a keyboard with one piece plastic top housing having an emitted light beam reflected off a finger to a detector when a finger is present in accordance with the teachings of this invention; 
         FIG. 1A  shows a finger placed on a key location of a keyboard with plastic top housing with an insert with key indicia printed or molded having an emitted light beam reflected off a finger to a detector when a finger is present in accordance with the teachings of this invention; 
         FIG. 2  shows a finger placed on a key location of a keyboard with a metal housing having an emitted light beam reflected off a finger to a detector when a finger is present in accordance with the teachings of this invention; 
         FIG. 3  shows a top view of a keyboard with a plastic housing with a plurality of key location openings for light beam finger detection in accordance with the teachings of this invention; 
         FIG. 4  shows a front view of the keyboard in  FIG. 3  in accordance with the teachings of this invention; 
         FIG. 5  is a flow chart showing the program in the microprocessor for controlling the keyboard in accordance with the teachings of this invention; 
         FIG. 6  is a schematic illustrating the microprocessor section of the keyboard in accordance with the teachings of this invention; 
         FIG. 7  is a schematic illustrating the emitter output section of the keyboard in accordance with the teachings of this invention; 
         FIG. 8  is a schematic illustrating the detector input section of the keyboard in accordance with the teachings of this invention; 
         FIG. 9  shows a finger placed on a key location with printed or molded key indicia of a keyboard with plastic top housing having and optional overlay where an emitted light beam reflected off a finger to a detector when a finger is present in accordance with the teachings of this invention; and 
         FIG. 10  is a flow chart showing the program in the microprocessor for two ambient detection for controlling the keyboard in accordance with the teachings of this invention; 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings,  FIG. 1  shows a keyboard  100  with a one piece planar top cover  106  forming the upper housing of keyboard  100  with an operators finger  128  placed over an opening  108  to block ambient light from influencing the output of emitter  118  and reflecting the output beam  126  to photo detector  114  via reflected beam  104 . Center LED emitter  116  outputs a beam shown by arrows  110  and  102  to illuminate the key indicia printed on top cover  106  so a user in low light ambient can see key indicia. Lower housing  112  covers printed wiring board  122  that provide connection circuitry for emitter  118 , photo detector  114  and LED emitter  116 . Output emitter  118  and detector  114  are generally of the 800 to 950 wave length in the inferred (IR) region and LED emitter  116  is in the visible wave length for the colors that a user may specify for there preference maybe red, yellow, green or other color. Opening  108  is shown dotted to show it is only an optical opening area that could be formed from a printed ink surround and is not a physical opening or hole, it is just an area. Top cover  106  is generally thought of as a substantially thin transparent or some degree of translucency in nature but could be of a IR transparent material and reduced in thickness at opening  108  location to allow visible emittance from LED emitter  116  to show or highlight key indicia. Having a one piece top cover  106  is very advantageous because the size of nuclear molecules are so small even the smallest crack can hide nuclear contaminates, and as with medical molecules there can be no crack or holes because when cleaning with cleaners that kill bacteria, even though the bacteria is dead it is still there in the crack or hole. 
       FIG. 1A  is of similar structure of  FIG. 1  with like item numbers being the same in both FIG&#39;S, keyboard  100   a  is shown with key indicia insert  106   a  has printed or molded key locational text is located in indicia recess  120  and allows top cover  124  to be of a clear material or of an opaque material with hole  108   a  to allow emitted beams to reflect off the finger or the relationship of the finger touching key indicia insert  106   a . Hole  108   a  would not be needed in top cover  124  if the material of top cover  124  is clear, transparent, or translucent. Embossed square  107  giving tactile locational feel for a users finger  128  is a very slightly raised square and could be only one to five mils high that protrudes up from planar surface of key insert  106   a  or could be molded into the keyboard in  FIG. 1  keyboard  100  top surface and made small enough as not to hold or harbor bacteria or other molecular contaminants, these areas are not needed for most users but can be added for a user preference when needed. 
       FIG. 2  shows a keyboard  200  with a top cover  206  forming the upper housing of keyboard  200  with an operators finger  228  placed over an opening  208  to block ambient light from influencing the output of emitter  118  and reflecting the output beam  226  to photo detector  214  via reflected beam  204 . It is not always necessary to block all the ambient from getting to photo detector  214 , if the keyboard is used in areas where there is no bright sunlight then opening  208  can be larger and let the digital signal processing (DSP) of the microprocessor  600  of  FIG. 6  differentiate the attenuation of the finger as it influences photo detector  214  to detect a finger. Center LED emitter  216  outputs a beam shown by arrows  210  and  202  to illuminate the key indicia printed on an insert in recess  220  of top cover  206  so a user in low light ambient can see key indicia. Lower housing  212  covers printed wiring board  222  that provide connection circuitry for emitter  218 , photo detector  214  and LED emitter  216 . Output emitter  218  and detector  214  are generally of the 800 to 950 wave length in the IR region and LED emitter  216  is in the visible wave length for the colors that a user may specify for there preference maybe red, yellow, green or other color. Opening  208  is shown to show it can be only an optical opening that could be formed from a printed ink surround and not a physical opening or hole depending on the material of top cover  206 . If top cover  206  is molded of a plastic like material opening  208  could be only of some degree of transparent or translucent and if top cover  206  is machined from metal or a plastic like material being opaque opening  208  can be a physical hole. Mounting recess  224  facilitates mounting keyboard  200  into another panel or the like or machine. 
       FIG. 3  shows a top view of keyboard  300  with a plastic housing and a plurality of key location openings  320  for light beam finger detection of key indicia  310 . Tactile raised area  330  at the base of the J indicia and the F indicia allows for finger detection to relate the index fingers of the left and ring hand to the key pattern, and key raised areas  340  also give finger tactile location to feel for keys and could be as small as one to five mils in height, these areas are not needed for most users but can be added for a user preference when needed. 
       FIG. 4  shows a front view of keyboard  300  of  FIG. 3  with a planar top surface  410 . 
       FIG. 5  is a flow chart showing the program in the microprocessor for controlling the keyboard where at INITIALIZE the processor starts and sets all of the output and input ports to their status and sends start up codes to a host for PS2 or USB, or if connected to a serial host then awaits instructions to start keyboard functions, or continues with PS2 or USB outputs. At IS DARK AMB USED if the keyboard is not going to be used in a dark ambient environment or in bright sunlight then goes on to SCAN FOR KEY DETECTION, if dark ambient is being used a question HAS DARK AMB BEEN STORED is ask and if needed goes to NO and does SCAN KEY MATRIX AND STORE DARK AMPLITUDE, and then goes to is DARK AMB REACHED meaning if a users finger has been placed over a key indicia location and blocked the ambient light from the detectors the amplitude of the detectors would of reached the dark ambient stored threshold and at YES the scan of the key location would start at SCAN FOR KEY DETECTION CHANGE FROM DARK and the IR emitter would be turned on to see if a reflectance was seen on the IR detector, then go to IS FINGER SENSED and if a reflectance is seen then YES and go to MATCH KEY OR OUTPUT FUNCTION and SEND CODE TO HOST and INC TO NEXT LOCATION and return, or if at IS FINGER SENSED a reflectance is not seen then INC TO NEXT LOCATION and return. If at SCAN FOR KEY DETECTION where the resulting from a NO at IS DARK AMB USED the IR emitter is turned on to see if a reflectance, as shown at the detector as an attenuation of diode output, is seen and tested at IS FINGER SENCED is YES then go to MATCH KEY OR OUTPUT FUNCTION and SEND CODE TO HOST and INC TO NEXT LOCATION and return, or if at IS FINGER SENSED a reflectance, as shown at the detector as an attenuation of diode output, is not seen then INC TO NEXT LOCATION and return. This process is continued until all keys on the keyboard are tested and then the process is started again. It should be understood by those skilled in the art that the keyboard could be any number of keys and not only the amount of keys shown in  FIG. 3 . 
       FIG. 6  is a schematic illustrating the microprocessor section of the keyboard with microprocessor  600  connected to and controlling of components like keyboard connector  604  as shown and plus it is controlling the inputs and outputs as shown that it also connected and controls the circuits in  FIG. 7  and  FIG. 8  via ports like  602 . 
       FIG. 7  is a schematic illustrating the emitter output section of the keyboard being controlled by control inputs  734  and can be for the IR emitters and the LED emitters  732  with current limiting resistor  731  and controlled by PFET  730  and NFET  733 , and being in a matrix depending on the amount of key locations the matrix could be made larger or smaller with the timing on and off being controlled by the microprocessor of  FIG.6 . 
       FIG. 8  is a schematic illustrating the IR detector input section of the keyboard and being in a matrix depending on the amount of key locations the matrix could be made larger or smaller and with digital signal processing (DSP) techniques or absolute detection timing is controlled by the microprocessor of  FIG. 6 . Having input control  821  and analog output lines  825  where the matrix is controlled by PFETS like  820  with blocking diodes  828  and IR detectors  826  being on when NFETS  829  are selected to sense outputs analog outputs over current sense resistors  822  that the IR emitter attenuates the photo diode and this attenuation is seen over the current sense resistor  822 . 
       FIG. 9  is of similar structure of  FIGS. 1 ,  1 A and  2  with like item numbers being the same in the FIG&#39;s.  FIG. 9  shows keyboard  900  with planar top cover  106  having a planar top surface forming the upper housing of keyboard  900  with operators finger  128  placed over substantially transparent area  902  to block ambient light from influencing the output of emitter  118  and reflecting the output beam  126  to photo detector  114  via reflected beam  104 . Center LED emitter  116  outputs a beam shown by arrows  110  and  102  to illuminate the key indicia printed on top cover  106  or overlay  910  so a user in low light ambient can see key indicia. Lower housing  112  covers printed wiring board  122  that provide connection circuitry for emitter  118 , photo detector  114  and LED emitter  116 . Opening  906 , like hole  108   a  in  FIG. 1A  or opening  208   FIG. 2 , having a depth  904  can vary in depth or thickness depending on the transparency of planar top cover  106  from an equal thickness of planar top cover  106  to a through opening  906  in planar top cover  106  where it can be covered by overlay  910  to a position as shown by arrow  908  where overlay  910  is under operators finger  128  and remain planar as planar top cover  106  while covering planar top cover  106  opening  906  to keep contaminates from entering keyboard  900  where overlay  106  then forms the substantially transparent area and maintains no holes or openings in keyboard  900  planar top surface. Key indicia can be placed on planar top cover  106  and covered by overlay  910  protecting it from an operators wear and tear or placed on overlay  910 . Locations  912  show a plurality of other key locations that can be on keyboard  900  depending on an application need. 
     It should be appreciated to those skilled in the art that although the FIG&#39;s. herein shows a limited key number that more keys or less keys are only a matter of reducing the size the key matrix or increasing the size of the matrix. 
       FIG. 10  is a flow chart showing the program in the microprocessor for controlling the keyboard where at INITIALIZE the processor starts and sets all of the output and input ports to their status and sends start up codes to a host for PS2 or USB, or if connected to some other type of serial host then awaits instructions to start keyboard functions, or continues with PS2 or USB outputs. At IS DARK AMB USED if the keyboard is not going to be used in a dark ambient environment or in bright sunlight then goes on to SCAN FOR KEY DETECTION, if dark ambient is being used a question HAS DARK AMB BEEN STORED if NO the process does SCAN KEY AND STORE DARK AMPLITUDE calibration, where present key is to be stored, YES, the program continues to SCAN KEY FOR 2ND DARK AMB calibration, if the second dark ambient calibration matches first dark ambient calibration stored the program continues to SCAN FOR KEY DETECTION, if NO the program increments to the next key location and starts again. A YES at 2ND DARK AMB MATCH means a users finger has been placed over a key indicia location and blocked the ambient light for a series of at least two subsequent detections and a match or are substantially the same the process continues to SCAN FOR KEY DETECTION, or if at SCAN FOR KEY DETECTION where the resulting from a NO at IS DARK AMB USED, in either case, the IR emitter is turned on to see if a reflectance is seen on the IR detector and that it is substantially different, then go to IS FINGER SENSED and if a reflectance, substantially different, is seen then YES and go to MATCH KEY OR OUTPUT FUNCTION and SEND CODE TO HOST and INC TO NEXT LOCATION and return, or if at IS FINGER SENSED a reflectance is not seen then INC TO NEXT LOCATION and return. If at SCAN FOR KEY DETECTION there is not substantially different at NO the process increments to the next location and starts again. This process is continued until all keys on the keyboard are tested and then the process is started again. It should be understood by those skilled in the art that the keyboard could be any number of keys and not only the amount of keys shown in  FIG. 3 . 
     While the invention has been described in terms of a single preferred embodiment, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the appended claims.