Abstract:
A D/A integrated pressure key for a keyboard is disclosed. A digital signal output first when a pressure is applied on the single key, and then an analog signal output while applying a bigger pressure over the same key. The magnitude of the analog signal output is positively related to the magnitude of the pressure applied on the integrated pressure key.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to a pressure key used in a keyboard, especially a digital/analog integrated pressure key which is capable of being able to output a digital signal first, and then output an analog signal while maintaining the digital signal on. 
         [0003]    2. Description of Related Art 
         [0004]    FIG. 1 is a prior art 
         [0005]    FIG. 1 is a two-pressure-key system disclosed in US2010/0148999 which is used in a keyboard for outputting a digital signal and an analog signal. It discloses an analog key 202 and a digital key 203. In operation, depressing the analog key cap 202 shall cause an analog signal output 220, and depressing digital key cap 203 shall cause a digital or on/off output 222. The analog key provides a variable output, and the digital key provides a momentary-on output. A plastic base 212 supports the key structure. A flexible PCB (printed circuit board) 210 is provided on top of the base 212. The PCB 210 includes circuit traces or connections that provide for electrical signals to be generated and communicated when keys are depressed. Circuit connection 236 is used to provide digital output 222, and circuit connection pads 230 and 231 are used to provide the analog output 220. The next layer is flexible insulator 208, such as a flexible PCB without circuit connections. The next layer is another flexible PCB206 that includes circuit traces or connections that work in conjunction with the connections on PCB 210 to provide for electrical signals to be generated and communicated when keys are depressed. 
         [0006]    A relatively thin flexible layer 204 is provided above PCB 206. A flexible dome 215 is provided for analog key cap 202, and flexible dome 213 is provided for digital key cap 203. For the digital key, an actuator 214 is provided underneath the dome 213 that causes circuit trace 234 to be engaged with circuit trace 236 when the digital key cap 203 is depressed. When circuit trace 234 touches the circuit trace 236, a digital output 222 is provided. For the analog key, a conductive and flexible half-dome 216 is provided that flexes when depressed. The capacitance associated between circuit pad 231 and circuit pad 230 varies when analog key cap 202 is depressed. Essentially pad 231 and pad 230 are the two plates of a capacitor. The variable capacitance between these two plates is measured from signal trace 232 by sending this trace to capacitance reading circuitry. 
         [0007]    The separate key system is not an easy controlling device for a game player. A favorable controlling device for outputting a digital signal and an analog signal device needs to be devised. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a prior art. 
           [0009]      FIG. 2  is a first rubber dome button according to the present invention. 
           [0010]      FIG. 3  is a first embodiment according to the present invention. 
           [0011]      FIG. 4  shows digital signal output according to the present invention 
           [0012]      FIGS. 5˜7  show analog signal output according to the present invention 
           [0013]      FIGS. 8A˜8B  show the timing of digital signal and analog signal according to the present invention 
           [0014]      FIGS. 9A˜9B  show a modified circuit base according to the present invention 
           [0015]      FIGS. 10A˜10C  show top views of different rubber dome button according to the present invention 
           [0016]      FIGS. 10D˜10F  show section views of the rubber dome button of  FIGS. 10A˜10C . 
           [0017]      FIG. 11  is a second rubber dome button according to the present invention. 
           [0018]      FIGS. 2A˜12B  are section views of the second rubber dome button according to the present invention. 
           [0019]      FIG. 13  is a third rubber dome button according to the present invention 
           [0020]      FIG. 14  shows digital signal output for the third rubber dome button 
           [0021]      FIG. 15  show analog signal output according to the present invention 
           [0022]      FIGS. 16A˜16B  show a plastic cap is configured on a top of the rubber dome button 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    This invention discloses a D/A integrated pressure key which is able to output a digital signal and analog signal in the course of depressing the single pressure key to the bottom. 
         [0024]      FIG. 2  is a first rubber dome button according to the present invention. 
         [0025]      FIG. 2  shows a rubber dome button  500  which can be used in the present invention, has a base rubber ring  51  on a bottom; a dome  52  is configured on a top of the base rubber ring  51 ; a central button  53  is configured on a top center of the dome  52 ; a downward central bump  55  is configured under a bottom center of the rubber button  53 . A central recess  54  can be made in the top center of the rubber button  53 . 
         [0026]      FIG. 3  is a first embodiment according to the present invention. A circuit base  600  is configured on a bottom of the rubber dome button  500 . The circuit base  600  has a top substrate  61  and a bottom substrate  62 ; a top electrode  631  is configured under a bottom surface of the top substrate  61 ; a bottom electrode  632 , aligned with the top electrode  631 , is configured on a top surface of the bottom substrate  62 ; a gap  633  is configured between the top electrode  631  and the bottom contact  632 ; a pressure sensor ring  64 , configured between the top substrate  61  and the bottom substrate  63 , is configured concentrically with the top electrode  631 . The top substrate  61  is flexible; when the top substrate  61  is depressed to cause the top electrode  631  contacting the bottom electrode  632 , a digital signal shall output; and when the top substrate  61  is depressed against the pressure sensor ring  64 , an analog signal shall output. A hard spacer ring  65 , aligned with the base rubber ring  51 , is configured concentrically with the top electrode  631 , and is configured between the top substrate  61  and the bottom substrate  62  to function as a pressure-resistant block against the pressure from the base rubber ring  51  when a pressure is applied on the rubber dome button  500 . 
         [0027]    With the rubber dome button  500  configured on a top surface of the circuit base  600 , when the rubber button  53  is restorably depressed, the downward central bump  55  is restorably depressed to apply a first pressure on the top substrate  61  against the top electrode  631 ; and a downward crack bump ring  56  is formed temporarily and configured concentrically with the downward central bump  55  when the central button  53  is depressed to a degree; wherein a bottom tip of the downward crack bump ring  56  initially having a position above a bottom tip of the downward central bump  55 ; the downward crack bump ring  56  is able to apply a second pressure on the top substrate  61  against the pressure sensor ring  64  when the central button  53  is depressed further. 
         [0028]      FIG. 4  shows digital signal output according to the present invention 
         [0029]      FIG. 4  shows when the downward central bump  55  applies a first pressure on the top substrate  61  against the top electrode  631  to cause the top electrode  631  contacting the bottom electrode  632 , a digital signal shall output. At this moment, no pressure is applied against the pressure sensor ring  64 , no analog signal shall output. 
         [0030]      FIGS. 5˜7  show analog signal output according to the present invention 
         [0031]      FIG. 5  shows after the first pressure is applied, and if the central button  53  is depressed further, the downward crack bump ring  56  shall apply a second pressure on the top substrate  61  against the pressure sensor ring  64  to cause an analog signal to output.  FIG. 6  shows that a stronger analog signal outputs, the magnitude of the analog signal output is positively related to the magnitude of the pressure applied against the pressure sensor ring  64 . The pressure comes from the depressed downward crack bump ring  56 .  FIG. 7  shows that an even stronger analog signal outputs which is positively related to an even bigger pressure applied against the pressure sensor ring  64 . 
         [0032]      FIGS. 8A˜8B  show the timing of digital signal and analog signal according to the present invention 
         [0033]      FIG. 8A  shows Analog Signal versus Timing. The Analog Signal is arranged on the Y-coordinate with scales of Conductance, and the Timing is arranged on the X-coordinate with scales F 3 , F 4 , F 5 , F 6 , and F 7  each corresponding to a status of  FIG. 3 ,  FIG. 4 ,  FIG. 5 ,  FIG. 6  and  FIG. 7 . 
         [0034]      FIG. 8B  shows Digital Signal versus Timing. The Digital Signal is arranged on the Y-coordinate with scales of 1 and 0 which represents on and off respectively, and the Timing is arranged on the X-coordinate with scales F 3 ˜F 7  each corresponding to a status of  FIG. 3˜FIG .  7 . 
         [0035]    The analog signal occurs at F 5 , F 6 , and F 7 . Please refer to a status of  FIG. 5  for timing F 5 . Please refer to a status of  FIG. 6  for timing F 6 . Please refer to a status of  FIG. 7  for timing F 7 . At timing F 3 , neither digital signal or analog signal outputs. At timing F 4 , a digital signal  1  outputs. At timing F 5 , an analog signal occurs while the digital signal  1  continues. At timing F 6 , a bigger analog signal occurs while the digital signal  1  continues. At timing F 7 , an even bigger analog signal occurs while the digital signal  1  continues. 
         [0036]      FIGS. 9A˜9B  show a modified circuit base according to the present invention  FIG. 9A  shows gaps  61 G are formed in the top substrate  61 ; gaps  61  are configured in a position above the spacer ring  65 , and are configured along an inner side of the spacer ring  65 . The gap  61 G is provided to release a centripetal tension while the downward central bump  55  and/or the downward crack bump ring  56  is depressed against the top substrate  61  so that the downward crack bump ring  56  can be fully depressed against the top substrate  61 .  FIG. 9B  shows a top view of the top substrate  61 , where the configuration of gaps  61 G, the inner portion  612 , and the outer portion  613  are shown. Four quarter gaps are shown in  FIG. 9B  for an example, less number or more number of the gaps can be optionally adopted. The four quarter arc gaps  61 G of  FIG. 9B  are formed in the top substrate  61 , and are configured in a position above the spacer ring  65 , and are configured along an inner side of the spacer ring  65 . 
         [0037]      FIGS. 10A˜10C  show top views of different rubber dome button according to the present invention 
         [0038]    Top view of different designs for the rubber dome button  500  are shown in  FIGS. 10A˜10C .  FIG. 10A  shows that a recess  54  is configured on a top center of the central button  53 .  FIG. 10B  shows that a flat surface is made on a top surface of the central button  532 . 
         [0039]      FIG. 10C  shows that an upward central bump  542  is configured on a top center of the central button  53 . 
         [0040]      FIGS. 10D˜10F  show section views of the rubber dome button of  FIGS. 10A˜10C .  FIG. 10D  shows that a recess  54  is configured on a top center of the central button  53 .  FIG. 10E  shows that a flat surface is made on a top surface of the central button  532 .  FIG. 10F  shows that an upward central bump  542  is configured on a top center of the central button  53 . 
         [0041]      FIG. 11  is a second rubber dome button according to the present invention. 
         [0042]      FIG. 11  shows that a second rubber button  73  is devised according to the present invention. The second rubber button  73  has a base rubber ring  731  on a bottom; a circular wall  732  is configured on a top of the base rubber ring  731 ; a downward central bump  75  is configured under a bottom center of the rubber button  73 ; a downward bump ring  76  is configured under the bottom of the button  73 , and is configured concentrically with the downward central bump  75 ; and a bottom tip  751  of the downward central bump  75  is configured in a position below a bottom tip  761  of the downward bump ring  76 , please refer to the difference H between tip  751  and tip  761 . The downward central bump  75  can be restorably deformed to apply a first pressure on the top substrate  61  against the top electrode  631 ; the downward bump ring  76  is configured concentrically with the downward central bump  75 ; and the downward bump ring  76  is able to apply a second pressure on the top substrate  61  against the pressure sensor ring  64 . 
         [0043]      FIGS. 12A˜12B  are section views of the second rubber dome button according to the present invention. 
         [0044]      FIG. 12A  shows a vertical section view of the second rubber dome button  73  according to the present invention. The downward central bump  75  is configured in the bottom center and the downward bump ring  76  is concentrically arranged with reference to the downward central bump  75 .  FIG. 12B  shows a horizontal section view along line BB′ of the second rubber dome button  73  to show that the downward bump ring  76  is arranged to surround the downward central bump  75 . 
         [0045]      FIG. 13  is a third rubber dome button according to the present invention 
         [0046]      FIG. 13  shows that a third rubber button  83  is devised. The third rubber button  83  has a base rubber ring  831  on a bottom; a circular wall  832  is configured on a top of the base rubber ring  831 ; a downward central bump  85  has a fatter waist  851  which has a width W or a section area in middle latitude larger than a width or a top surface area of the electrode  631 . The downward central bump  85  is configured under a bottom center of the rubber button  83 . The downward central bump  85  is able to be restorably depressed to apply a first pressure on the top substrate  61  against the top electrode  631 . 
         [0047]      FIG. 14  shows digital signal output for the third rubber dome button 
         [0048]      FIG. 14  shows when the downward central bump  85  applies a first pressure on the top substrate  61  against the top electrode  631  to cause the top electrode  631  contacting the bottom electrode  632 , a digital signal shall output. At this moment, only a little sag in the center of the top substrate  61 , no pressure is transmitted against the pressure sensor ring  64 , and therefore no analog signal shall output. 
         [0049]      FIG. 15  show analog signal output according to the present invention 
         [0050]      FIG. 15  shows after the first pressure is applied on the top substrate  61 , to depress the central button  53  further, the elastic bulky chunk of the fat downward central bump  85  causes a bigger sag of the top substrate  61 . The bigger sag shall apply a second pressure on the top substrate  61  against the pressure sensor ring  64  to cause an analog signal to output. In other words, the downward central bump  85  is able to apply an inclined pressure  634  on the top substrate  61  against the pressure sensor ring  64  after the rubber button  83  is depressed further. The second pressure is at least partially generated by the central sag of the top substrate  61 , and the central sag is caused by a pressure of the bulky chunk of the downward central bump  85 . 
         [0051]      FIGS. 16A˜16B  show a plastic cap is configured on a top of the rubber dome button 
         [0052]      FIG. 16A  shows a plastic cap  87 , like the one seen on a key board, is configured on a top of the rubber dome button  500  adapted for being depressed by a user&#39;s hand.  FIG. 16B  shows a status that the plastic cap  87  is depressed. 
         [0053]    While several embodiments have been described by way of example, it will be apparent to those skilled in the art that various modifications may be configured without departing from the spirit of the present invention. Such modifications are all within the scope of the present invention, as defined by the appended claims.