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  1. #41  
    Quote Originally Posted by Drakej View Post
    Forget fingers and eyes. I want my screen to be able to take a genetic sampling from blood. You know, cut your finger a little (it censored p r i c k....) your finger and rub some blood on the screen. How soon until we see this app????
    I hear it is in production. It is called the Palm Audrey 2. I've heard the phone will get an insatiable appetite for blood, and start making us feed our friends to it.
  2. #42  
    Quote Originally Posted by TIWizard View Post
    (jbg, might want to explain how the screen works in....a less technical way? :P)
    Wow, I thought the rubber sheet thing was pretty good. I was really proud of myself there for a minute. Guess I missed the mark.

    Let's try it this way: you know those executive desk toys that are an assortment of pins that you can press your hand or face into and you get sort of an image in the pins? I mean this thing:

    Okay, now imagine that this is what the Pre screen is like. If you touch it with your finger, you depress multiple pins. Because multiple pins are depressed, you can imagine where the finger is pretty precisely, even though the pins are spaced apart. But you haven't a prayer of figuring out what the fingerprint looks like. This is more or less the way the Pre's screen works, except it is doing it electrically instead of mechanically.
    Palm III-->Handspring Visor-->Sony Clie PEG-NR70-->no PDA -->Palm Treo 755p-->Palm Pre-->HP Veer
  3. ssrjazz's Avatar
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    #43  
    Mythbusters showed that thumbprint scanners aren't really all that secure anyway and can be easily fooled.
  4. #44  
    Quote Originally Posted by caferacer View Post
    There once was an old program like that for the Palm VII I think....

    You places your thumb on the screen, and it scanned it.

    Except it was fake, and if you held the directional button down while scanning it would 'pass' you. Twas fun screwing with friends with that app.

    But seriously, no it's not possible.
    Called Thumbscan. I've got it on my Treo. Definitely good for a laugh once in a while.
    Bob Meyer
    I'm out of my mind. But feel free to leave a message.
  5. #45  
    Touchscreens will not do that, period. Good thought though. Older style touchscreens (like the older Palm's.. resistive I think it's called?) simply sense pressure. They don't "see" your finger, nor have enough sensitivity to sense individual ridges in your fingertip.

    This part I may be incorrect about, but I *think* I understand correctly. Someone PLEASE chime in if I am wrong (I hate giving bad info). Screens like ours (captive I believe it's called) have dots and lines. If you look at an angle, you can see them. When you put your finger on the screen, the dots sense heat/pressure. So many dots/lines need to sense the heat to complete a "circuit" and allow the phone to recognize where you are pressing (why stylus's don't work unless you get the huge ones to connect dots/lines with a single press). Just from personal testing, I believe 4 dots need to be connected, but that's just from purely unscientific curiosity type testing. There is simply no way for the screen to know about all the little ridges in your finger, or anything in between the dots and lines that are being connected for that matter. Sensing a rough guesstimate of the SIZE of your finger, maybe, but that is about it.
  6. #46  
    Quote Originally Posted by Centro85 View Post
    Touchscreens will not do that, period. Good thought though. Older style touchscreens (like the older Palm's.. resistive I think it's called?) simply sense pressure. They don't "see" your finger, nor have enough sensitivity to sense individual ridges in your fingertip.

    This part I may be incorrect about, but I *think* I understand correctly. Someone PLEASE chime in if I am wrong (I hate giving bad info). Screens like ours (captive I believe it's called) have dots and lines. If you look at an angle, you can see them. When you put your finger on the screen, the dots sense heat/pressure. So many dots/lines need to sense the heat to complete a "circuit" and allow the phone to recognize where you are pressing (why stylus's don't work unless you get the huge ones to connect dots/lines with a single press). Just from personal testing, I believe 4 dots need to be connected, but that's just from purely unscientific curiosity type testing. There is simply no way for the screen to know about all the little ridges in your finger, or anything in between the dots and lines that are being connected for that matter. Sensing a rough guesstimate of the SIZE of your finger, maybe, but that is about it.
    That's nearly correct, except it's called "capacitive" and it has nothing at all to do with heat. It's an electrical signal. I confess I'm not totally sure what the dots and lines are, but they are capacitive sensors of some sort (the pins in my analogy above).
    Palm III-->Handspring Visor-->Sony Clie PEG-NR70-->no PDA -->Palm Treo 755p-->Palm Pre-->HP Veer
  7. Shadnic's Avatar
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    #47  
    Quote Originally Posted by Centro85 View Post
    This part I may be incorrect about, but I *think* I understand correctly. Someone PLEASE chime in if I am wrong (I hate giving bad info). Screens like ours (captive I believe it's called) have dots and lines. If you look at an angle, you can see them. When you put your finger on the screen, the dots sense heat/pressure. So many dots/lines need to sense the heat to complete a "circuit" and allow the phone to recognize where you are pressing (why stylus's don't work unless you get the huge ones to connect dots/lines with a single press). Just from personal testing, I believe 4 dots need to be connected, but that's just from purely unscientific curiosity type testing. There is simply no way for the screen to know about all the little ridges in your finger, or anything in between the dots and lines that are being connected for that matter. Sensing a rough guesstimate of the SIZE of your finger, maybe, but that is about it.
    A lot of that is wrong...it's not just about hitting enough dots. Try taking like a plastic water bottle and trying to move your screen around the with lid. Did it work? No, but it's still bigger than your finger. Capacitive touch screens (as someone explained fairly well in the last page) work with the elecricity in our fingers to measure where we're touching the screen. Pressure does not matter (unless the screen is not very sensitive), and size does not matter (that's not what she said ).
  8. #48  
    Use the camera for facial recognition.
  9. #49  
    Surface area does matter as a function of the conductivity of the object being used to touch the sensor. Try stacking pennys edgewise and writing on a (protected) screen, you need 3 or 4 pennys to get a response.
  10. #50  
    Quote Originally Posted by jbg7474 View Post
    Wow, I thought the rubber sheet thing was pretty good. I was really proud of myself there for a minute. Guess I missed the mark.
    I was talking about the first part. I didn't see the rubber sheet thing

    /offtopic
    Sprint Palm Pre - WebOS 2.1 > Sprint HTC Arrive
  11. #51  
    Quote Originally Posted by Centro85 View Post
    Touchscreens will not do that, period. Good thought though. Older style touchscreens (like the older Palm's.. resistive I think it's called?) simply sense pressure.
    it actually doesn't- a resistive screen responds to pressure, but doesn't sense the pressure from your touch. the pressure causes two electrical layers to contact causing a change in v gradient, which is sensed.


    Screens like ours (captive I believe it's called) have dots and lines. If you look at an angle, you can see them. When you put your finger on the screen, the dots sense heat/pressure. So many dots/lines need to sense the heat to complete a "circuit" and allow the phone to recognize where you are pressing (why stylus's don't work unless you get the huge ones to connect dots/lines with a single press).
    *capacitive* screens sense neither hear, nor pressure. pressure isn't required at all. the 'dots' are probably capacitive sensors? the screen works by sensing a change in capacitance when you touch the screen- this is why none capacitive materials don't work on the screen- even if it's the same temp as your finger and applies pressure. it's also why when you're less conducting- like when your skin is dry or has a callous on the tip, it doesn't work so well.


    Just from personal testing, I believe 4 dots need to be connected, but that's just from purely unscientific curiosity type testing.
    i'm not sure what you're saying about 'connecting.' each point in the grid of the sensors of the pre has capacitance measured by itself. otherwise multitouch wouldn't be possible.
  12. #52  
    Quote Originally Posted by TIWizard View Post
    I was talking about the first part. I didn't see the rubber sheet thing

    /offtopic
    'sokay--I actually like my pins analogy better (though it doesn't seem to be resonating).
    Palm III-->Handspring Visor-->Sony Clie PEG-NR70-->no PDA -->Palm Treo 755p-->Palm Pre-->HP Veer
  13. #53  
    Whenever you want to know something, hit Wikipedia.

    Projected Capacitive Touch (PCT) technology is a capacitive technology which permits more accurate and flexible operation, by etching the conductive layer. An XY array is formed either by etching a single layer to form a grid pattern of electrodes, or by etching two separate, perpendicular layers of conductive material with parallel lines or tracks to form the grid (comparable to the pixel grid found in many LCD displays).

    Applying voltage to the array creates a grid of capacitors. Bringing a finger or conductive stylus close to the surface of the sensor changes the local electrostatic field. The capacitance change at every individual point on the grid can be measured to accurately determine the touch location.[6] The use of a grid permits a higher resolution than resistive technology and also allows multi-touch operation. The greater resolution of PCT allows operation without direct contact, such that the conducting layers can be coated with further protective insulating layers, and operate even under screen protectors, or behind weather and vandal-proof glass.
    Generally, touchscreens return the touch data in the form of blobs. It gives a location (x,y coordinates), size (radius), and magnitude (harder presses produce more capacitance) of the touch.

    This isn't CSI. Touchscreens can't read fingerprints any more than a camera could read a novel from taking a picture of the cover.
    Quote Originally Posted by Brain_ReCall
    I'm an Embedded Software Engineer. My idea of a Good User Interface is printf().
  14. #54  
    Well, there you go That was just what I had gotten from doing some quick research into it, glade we have people here that REALLY know whats going on.

    Multi-touch - Wikipedia, the free encyclopedia
    Multi-touch consists of a touch screen (screen, overlay, table, wall, etc.) or touchpad, as well as software that recognizes multiple simultaneous touch points, as opposed to the single touchscreen (e.g. computer touchpad, ATM), which recognizes only one touch point. This effect is achieved through a variety of means, including: heat, finger pressure, high capture rate cameras, infrared light, optic capture, tuned electromagnetic induction, ultrasonic receivers, transducer microphones, laser rangefinders, and shadow capture.[1]

    That is one of the places I got my bad info from.

    If anyone is interested, this seems like a pretty basic explanation of our screen and why thumbprint wont work. What the others have said is in there, so its probably pretty accurate.
    HowStuffWorks "Multi-touch Systems"
    Click iPhone Touch Screen for more details.
  15. #55  
    Here's an idea. Change his dial pad for his passcode screen to one big finger print.
  16. #56  
    Quote Originally Posted by pogeypetey View Post
    Hmmmm, you know what else might be cool? Having a retinal scanner. What would it take to get the touchscreen to do that?
    Use the camera! Now that would rock!!!
  17. Phenom's Avatar
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    #57  
    I don't need a fingerprint scanner. I homebrew'd my Pre to self-destruct if anyone else tries to use it without my authorization (I call it the Jack Bauer CTU Limited Edition Pre app). My wallpaper is also a picture of me holding a .50 cal handgun to the head of a kitty trying to hack into my Pre. Bad kitty!
  18. #58  
    Quote Originally Posted by Brain_ReCall View Post
    Whenever you want to know something, hit Wikipedia.
    Ooooh yeah. Wikipedia rocks:

    Bir Tawil - Wikipedia, the free encyclopedia - a piece of land not claimed by any country.

    UFO-Memorial Ängelholm - Wikipedia, the free encyclopedia - memorial to a UFO landing in Sweden

    and my favorite-

    Reality Checkpoint - Wikipedia, the free encyclopedia - a named lamp post.
  19. DSPKweb's Avatar
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    #59  
    [QUOTE=Phenom;1900086]I homebrew'd my Pre to self-destruct if anyone else tries to use it without my authorization (I call it the Jack Bauer CTU Limited Edition Pre app). QUOTE]

    That is hilarious!!!!! Does it have a digital countdown and the sound effects to let em know their screwed?
    Sanyo SCP 4500 > Samsung SCH 1900 > Sanyo SCP 5000 > Treo 755p > Palm Pre > HTC Evo
  20. #60  
    For my pda there was a picture password app. it was a picture of say a car.. The app would allow you to say touch the left headlight and right tire and it would unlock the pda for use.
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