Tag Archives: 3d

Fluorescent microsphere mist displays

A few 3D mist displays have been demonstrated over the last decade. I’ve seen a couple at trade shows and have been impressed. To date, they use mists or curtains of tiny water droplets to make a 3D space onto which to project an image, so you get a walk-through 3D life-sized display. Like this:


or check out: http://ixfocus.com/top-10-best-3d-water-projections-ever/

Two years ago, I suggested using a forehead-mounted mist projector:


so you could have a 3D image made right in front of you anywhere.

This week, a holographic display has been doing the rounds on Twitter, called Gatebox:


It looks OK but mist displays might be better solution for everyday use because they can be made a lot bigger more cheaply. However, nobody really wants water mist causing electrical problems in their PCs or making their notebook paper soggy. You can use smoke as a mist substitute but then you have a cloud of smoke around you. So…

Suppose instead of using water droplets and walking around veiled in fog or smoke or accompanied by electrical crackling and dead PCs, that the mist was not made of water droplets but tiny dry and obviously non-toxic particles such as fluorescent micro-spheres that are invisible to the naked eye and transparent to visible light so you can’t see the mist at all, and it won’t make stuff damp. Instead of projecting visible light, the particles are made of fluorescent material, so that they are illuminated by a UV projector and fluoresce with the right colour to make the visible display. There are plenty of fluorescent materials that could be made into tiny particles, even nano-particles, and made into an invisible mist that produces a bright and high-resolution display. Even if non-toxic is too big an ask, or the fluorescent material is too expensive to waste, a large box that keeps them contained and recycles them for the next display could still be bigger, better, brighter and cheaper than a large holographic display.

Remember, you saw it here first. My 101st invention of 2016.

25th anniversary of stick interface for 3D world play,

I don’t have the exact date when I thought this up so it might be a week or two out, but late 1991 certainly, so I thought I’d celebrate its 25th anniversary by blogging the idea again.

The idea was a simple stick with simple reflectors on it that could easily be tracked using an infrared beam and detector(s). Most tools and especially tools for making crafts or drawing can be approximated by a stick, and we all have a lifetime of experience in manipulating sticks, so they would be the perfect interface, and cost almost nothing to make. Here’s a pretty picture:

Stick 2.0

Stick 2.0

You can easily imagine how you could use such a stick to carve out a wall or a roof or a piece of furniture in your 3D world, or to play any kind of sports. Nintendo built a complex wand device to do this expensively, but really a simple stick can do most of that too.

Forehead 3D mist projector

Another simple idea. I was watching the 1920s period drama Downton Abbey and Lady Mary was wearing a headband with a large jewel in it. I had an idea based on linking mist projection systems to headbands. I couldn’t find a pic of Lady Mary’s band on Google but many other designs would work just as well and the one from ASOS would be just as feasible. The idea is that a forehead band (I’m sure there is a proper fashion name for them) would have a central ‘jewel’ which is actually just an ornamental IT capsule containing a misting device and a projector as well as the obvious power supply, comms, processing, direction detectors etc. A 3D image would be projected onto water mist emitted from the reservoir in the device. A simple illustration might help:

forehead projector


Many fashion items make comebacks and a lot of 1920s things seem to be in fashion again now. This could be a nice electronic update to a very old fashion concept. With a bit more miniaturisation, smart bindis would also be feasible. It could be used with direction sensing to enable augmented reality use, or simply to display the same image regardless of gaze direction. Unlike visor based augmented reality, others would be able to see the same scene visualised for the wearer.

The future of sticks

With the current IT patents fiasco, it’s only a matter of time before someone tries to patent sticks. So, just for the record, prior art exists, right up to using them for highly sophisticated 3d interfaces. I published my ideas on the future use of sticks as computer interfaces in 1991, but made no attempt to patent them. Sticks belong to everyone and all I did was to add a few pretty obvious electronics updates, so I’d hate for any company to try to steal this market, which should be left open to all. So doing my bit to protect the right to use sticks for everyone during the patents grabs, here is my original, and if need be I have the original signed paper version to prove prior art:


shows the 1991 version I wrote while in BT, and it has been updated slightly a few times since.

Check the paper for some simple graphics if your imagination needs provoking, but here is a quick summary of the main points. 

Sticks are one of the most primitive tools. Humans have been using sticks for hundreds of thousands of years, so we are pretty good at it. Sticks are used for many very different purposes. Stick a few bristles on the end and you have a brush, make the end or edge hard and sharp and you have a chisel, an axe, a knife, a sword or scalpel, make it glow a bit and it becomes a light sabre. Hollow it out and you have a blowpipe, add a few bits to that and you have a gun. Hammers, sports rackets or clubs, many everyday objects can be approximated as a modified stick. Stick manipulation skills can be used as a base for many others.

Now let’s bring sticks into the realm of pads, and in particular 3D interfacing. Some pads already let you draw on them using small pointy sticks. It really isn’t very hard to extend that to 3d drawing. All you need is to be able to track both ends of a stick. Put a ball on each end of the stick, use a couple of LEDs and a receiver to spot where the reflections come from, and you’re there. The wii, xbox and playstation all have some basic 3d tracking and gesture recognition now, so it just needs slight adaptation to make it almost universally applicable.

There are lots of possible variations in the means of tracking the ends of a stick. You could use complex systems with gyros and dead-reckoning systems, but more easily and cheaply, you can use simple LEDs to illuminate the ends, and use quadrant photodiodes to triangulate them. Alternatively, raster scanning a light beam (from a laser or LED) with the direction encoded on the beam allows much greater precision – this sort of system is used in some missile guidance systems. Using multiple receivers or transmitters adds more precision still. If the balls at the end of the stick are striped, then the magnitude of the reflection will vary sinusoidally as the stick rotates, allowing the twist of the stick to be measured as well as orientation and location. Extra reflectors could be added to let the stick produce a curve. Two or more sticks could be used in combination to create planar or dynamic data. All this so far just uses a simple stick with reflectors. Adding electronics or smart materials to the stick, changing the colour of the ends to vary reflected spectrum or making them flash or pulse gives still further scope for extra data. You could go the whole hog, but then you’ve got a Wii remote.

All this allows a simple stick to be used as the basis for an extensive sculpting and drawing tool-kit  As 3d printers and virtual worlds become more important in everyday life, we will soon need lots of 3d interfacing, and I feel sure that stick-based tools will dominate.

We understand sticks. Let’s try to keep patents away from them.