Speed and cost of switching LCD segment

LCD is slow.

Which kind of hits on a project I'm currently developing at work.

Using a video recognition system to look through an object of rotating wires being cabled with a silicone grease dispenser high pressure pump that files the cavity in the center.

Using optical targeting systems work 75%, but we're trying for a

100% target acquisition to determine, if, the high pressure pump system needs to replenish the silicone as it's being consumed by the water blocked cabled product that is being grouped, with out waste.

You can imagine the cost of materials and profit margin which drives to development of these devices.

It's been 25 years since I've gotten into a project like this, the last time I used camera's in this fashion was with a Z80 computer based system using a B&W camera with high res to perform a line inspection of those large squeeze bottles of the "Hershey Chocolate" bottles to determine if the label was correctly applied on the bottle and reject it, if not. Because the bottle and Label are both the same color and the only variations were the image of data on the label itself, in Silver, made for a tricky out come. But it was successful. And this was done in the computer language "FORTH".

Of course, with today's technology, this project is being done in Windows using delphi as the front end. All is coming along just fine. We're planing on using a mini Windows XP panel screen to operate this when completed.

So, if you are a computer jock, I guess you could use a LCD web cam to look at the watch and then acquire your information! :) OCR

Have a good day..

On a sunny day (Sun, 01 Nov 2009 11:53:51 -0500) it happened Jamie wrote in :

Of course?

LCD webcam? Most webcams are CMOS, you must have ment CCD.

My digital watch changes segments so slow that you would get less then a 1 Baud bitrate. OK, with seven segments 7 Baud?

Just beware of that blue windows screen. hehe

e e

The kinds of LCD used in battery powered watches are slow, gonna take a tenth of a second or so. Other types of modulator are faster (even moving-mirrors, but especially quantum dots...) but aren't ready for low-cost consumer items.

It's possible to parallel a few dozen segments, of course; a tenth second for a 32-bit parallel port, readout by a low-resolution camera...

Didn't the Timex gizmos use a photovoltaic cell? You can power an LED with a cradle that beams light into a PV cell... and maybe use IRDA protocols.

Can the watch draw power from the cradle? Maybe via a pair of contacts, or perhaps some inductive transfer scheme. If so, it doesn't have to rely in the little lithium cell, and watch power isn't a factor either.

Mike

This probably has the info you need on power vs speed.

e

eLCDsegments, which are read by the cradle.

There is a second limiting issue, if you want to use some CMOS camera to read the data, and if it does say 30 fps, then Niquist tells you you cannot flip segments faster then 15 x per second else you get aliasing.

Say you have 4 digits, seven segments each, that makes 28 segments, at 15 changes per segment per second, makes 420 bits / second max, you need to be a bit lower, so say 300 Bd is the maximum you can ever do that way.. You could use photo transistors with lenses looking at each segment to up speed, but that would be really complicated mechanicaly. But I think it is a fun idea. Maybe a faster CMOS sensor? Those do exist.

ode

theLCDsegments, which are read by the cradle.

But Claude Shannon said there's more to achieve.

Let's Say you could use a Bandwidth of 10Hz per Segment (mainly limited by the LC Material). Each Segment should give a S/N of 100Db at this low rate. This means roughly 150 Bits/s/segment =3D 150*28 =3D 4200 Bits/s

Probably better transmitting data using the LCD backlight.

--
Adrian C

On a sunny day (Mon, 2 Nov 2009 07:39:31 -0800 (PST)) it happened untergangsprophet wrote in :

That is true, parly switching a segmant would give more values then a 0/1 value. But I am not sure how 'analog' you can drive a watch segment.

On a sunny day (Mon, 02 Nov 2009 15:56:53 +0000) it happened Adrian C wrote in :

Very clever! :-)

A very nice idea indeed!!