jr67960@tut.fi (J Rantala) (10/21/89)
(This is not really my business, but I let it go anyway. Sorry if mis-spelling english.) Sorry if You think that this is a wrong newsgroup to this article. Just a little background first. I read one article (from an unrelated newsgroup), where some person was searching a math program, which would be easy to use, "better than paper and pencil" (with drawing capabilities). I can't be absolutely sure, what that person accurately meant, but that did bring to my mind the question of input devices to a computer system. I guess there is many things which are not very easy to do with current input devices (mouse, digitab's and what ever there is), such as free-hand writing(!), _painting especially, and other such type works which require very rapid but accurate() movements. I suppose that a system which would consist of a flat screen with an extrenal (without connecting wibers) "pencil" would be rather good, if the flat screen would have hard covered front of it, so that it would be possible to put it down above the table (where Your keyboard is just now). Why(?), since then it would be possible to use it like normal book and paper/pencil...(*) Well, yes, there does exist "light pen" -like systems, but they are always restrected to have physical connection (wire) to the other parts of the system. In addition, they have a few restrictions to the addressing methods used in the main display, and they are, basically, not quick enough (as far as I know). Thus, I became interested, whether there exist any other way to catch down the position of the pen-like input device. In order to gain higher speeds and other properties, I guess, it should (please note that, I might be talking about something which does already exist, but anyway I haven't heard/seen any such) be independent of the main display, but still possible to see thrue it (since it must be directly above the main display). But then there should be some other methods to catch the position, than those various infrared beam systems, since it should be possible to cover the transparent input device by whatever, without causing any random input signals, together with great accuracy. One possibility might be, I suppose, if there would be any way to cause e.g. a delay to a bypassing current signal when there is a normal network of crossing lines, vertical and horizontal lines being separately driven (independently of each other), since then the driving of the network would be very easy (requiring only one delay port&diode per line) having only two input/output lines. The point is, then, does there exist any such electrical effect (commonly known), which can be produced via e.g. presence of external magnetic field or low level heat or other such way, so that the resulting effect to the electrical properties of that wire, made from appropriate material, would be momentarily measurable in a given position. I guess those materials used with ferroelectric/electrochromic/cathodochromic or other variative display systems might be just a little interesting. If that is not possible, I guess the other way around might be the use of (digital type) switches (color-LCD) in the place of above line, if it can be configured so that external field can switch it off and back on, using appropriate barriers. (*): The pointing device itself should have, in order to be usable, a way to give "glitches" to a program, thus the effect should be capable to handle different types of external field signals (the pen having, in addition, on/off property (it's not enough to just take it away from the panel)) in a form of different strength or so. However, that's not needed. It might be useful at least in character recognition (from free hand-text in the moment when it is written down, since if the way by which a character is written is known, it might be easier to differentiate between characters (relative to one person in a given time: some people like better to write down with ordinary pen than to use keyboards, some of them being capable to write down quicker than typewriting with a keyboard)). Thus the same input device might possibly be used in the place of keyboard. I know that there is much momenta against that, since the current way of thinking seems to be to get as far from the "old" styles of producing output (pencil, paper, etc.) as though it would be the _only "intelligent" way. In a huge number of cases it is. But still, the most natural (and productive) way to produce anything (in the case of human output in this era) is the case when the position of the human hand and the look of the eyes will match in the same place (not really, but in a brutal and violetive way it can be said); with the mouse and keyboard system, you can't always do your job with best benefit, at least since you must use many devices and step between them. What a story.. -j rantala 5[%c\2[(7 jr67960@tut.FI (INTERNET or UUCP or FUNET or BITNET or EARN) funet:jr67960@tut.FI (ELISA-post) ttkklk::tutor::jr67960 (DECnet) (%244231*) Official mail: '... sending out the message in a bottle ...'
aez@Data-IO.COM (Adam Zilinskas) (10/24/89)
In article <2300@tutor.tut.fi> jr67960@tut.fi (jr67960@tut.funet uunet!mcvax!tut!jr67960) writes: > > ... <stuff about > ... "better than paper and pencil" ... > >-j rantala There are several "touch screen systems" I know of, most are not too useful except for selecting items off menus. 1. Brute force method: I saw a piece of test instrument from Fluke that had a mechanical contact touch screen. It consisted of two closely spaced mylar sheets with a very thin gold plating forming a cross-point switch mechanism. The gold was thin enough to be relatively transparent but would cause current flow if the mylar sheets were squezed with a finger. The problems with it was that the switch contact areas were fixed locations, the gold could tarnish/damage causing "bounces", and since physical contact was required, the screen would get mucked up easily. 2. photo-beam grid. I think HP developed this but I could be wrong. Here, a grid of infra-red beams criss-cross the screeen face. Placing anything near the screen would disrupt two or more beams and you could tell approximately where to "touch" was. Best place I seen it used was in EPCOT center in Florida where the "electronic maps" had touch-menus, you needed to only go within an 1/2" to the screen to activate but people still always tried to break thier fingers getting the maps to work faster (the Bernoulli affect, harder the key is pressed, the faster the data is squirted out of the machine :-) The problems here is again the physical limits of the beam sizes make the active areas fairly large and fixed. 3. doing it with mirrors. I never saw a real machine with this just specs. Here instead of a grid of beams, a small rotating beam and sensor sits in one corner of the screen and the opposite edges are mirrors. The beam sweeps across the screen ala RADAR station and the sensor catches the return from the mirrors. Placing a finger in the screen will disrupt the beam twice, once during the direct beam at the finger, and once during the carom shot off the mirrors at the edge of the screen. The finger location is then triangluated. The problem here is first, a mechanical element is constantly moving and the computations to triangulate are typically more complex than the application. I have seen talk about systems where a headset calculates the head position to move a cursor, fancy optics "watch" eye movement and follow it on the screen, all sound cumbersome, expensive and useable only in situations like fighter jets where the user is so strapped in, little adjustments are needed. There was a thread of discussion about non-keyboard interfaces and I think the results were not conclusive, some could type 90 WPM and others scribble at that rate. Personally, I think keyboards (QWERTY, Chord or otherwise) is best for textual input (non ambigouous) while mouse/digitizer pads are best for graphical input. A better approach is to design a keyboard so that reaching for the trackball/mouse is easy so that the transistion between between keyboard (figners at home position) and mousing (move-pointer with fine eye-hand coordination) is quick. A good location may be below the space bar in the QWERTY keyboard for thunb operated trackballs. Adam Zilinskas If it does have anything to do with PLDs it isn't Data I/O's concern