Pinpoint Precision Stylus how does it work?

Discussion in 'General Electronics Chat' started by ajrenzetti, Mar 21, 2014.

  1. ajrenzetti

    Thread Starter Member

    Dec 20, 2010
    40
    0
    I'm thinking of creating my own version of the stylus made by the joy factory. Here's a link to the stylus: http://www.thejoyfactory.com/product/bcu201

    The description says the stylus generates an electromagnetic field around the tip, which fools the capacitive touch screen into thinking a finger of larger diameter is touching it, which allows for a smaller tip than usual.

    Does anyone know how its doing this? Im guessing there's a winding further up the stylus thats connected to a small signal generator that generates the same frequency as a human finger. Im not completely sure if this is accurate though, since the em field seems like it might be coming from the tip itself and not the winding.

    any info would be very helpful, thanks
     
  2. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    what is the frequency of a human finger? 45 years in electronics and rf, and I have never heard of that.
     
  3. joeyd999

    AAC Fanatic!

    Jun 6, 2011
    2,679
    2,738
    It very much depends upon what that finger is doing...
     
  4. joeyd999

    AAC Fanatic!

    Jun 6, 2011
    2,679
    2,738
    Even more amazing, in my book, is the Samsung S-Pen available on the Note tablets. It works nearly an inch off the surface, and is powered inductively by the tablet.

    Here's a rundown of how it works.
     
  5. ajrenzetti

    Thread Starter Member

    Dec 20, 2010
    40
    0
    its crazy, i know. ive never heard of a stylus that can work on any capacitive touchscreens with such a small tip. i was researching how it might work and stumbled upon this document: http://www.google.com/patents/US20100053113

    not quite sure if this is how it works, but i hope its a little more simple than that.

    also, when i checked the frequency of my fingertip, the meter read around 60hz
     
  6. ajrenzetti

    Thread Starter Member

    Dec 20, 2010
    40
    0
    this is how most active stylus's work. the stylus im referring to, however, does not require software to use, and can be used on any capacitive touch screen.
     
  7. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,798
    1,103
    Perhaps I'm missing something but I don't see the point (pardon the pun ;)). If the tablet is fooled into thinking a fat finger is on the screen then it will behave the same whether you use this magic stylus or a fat finger. What do you gain?
     
  8. ajrenzetti

    Thread Starter Member

    Dec 20, 2010
    40
    0
    you gain the ability to do things that require more precision, such as sketching. Have you ever tried to sketch a picture on a capacitive touch screen? even with a passive stylus it is incredibly difficult to do so. with this, you have a much smaller tip and have more accuracy with sketching.
     
  9. ajrenzetti

    Thread Starter Member

    Dec 20, 2010
    40
    0
    so does anyone have any idea how this thing is working? i want to at least get general details on how it might work before i go on experimenting with different prototypes.
     
Loading...