Countertop Video Projector?

bcorrigan78 asks: "After reading the recent Slashdot post regarding Microsoft's perfect home, I got to wondering if there was a way to build or buy a counter-top projector like the one pictured in the article here. It looks like it might be some kind of laser scanning low-res projector? Anyone seen anything like this?"

Comments

Now I have to go die in the desert

[orthogonal]

Oh God!

I looked up!

Owwwwww!

Right into the laser!

I'm blind! I'm blind! I'm blind!

(Now I must give my water to the desert! No mechanical eyes for me!)

maybe from the bottom up

[Naikrovek]

i think it would be better if it shined from the bottom up - as a previous poster insinuated, looking up into a laser (or other bright light) could be not only painful but dangerous.

Mounting something inside a counter shining up onto a peice of darkly smoked or ground (underside only) glass would be sexier too, I'd say. And probably easier to work on and easier to set up.

But to answer your question, no, i don't know of anything that could do this.

Re:maybe from the bottom up

[jafuser]

If this is being done on a counter, you would lose the storage space within.

Re:maybe from the bottom up

[Lars T.]

Yeah, you are right, placing something like a bright lamp over a table is obviously a bad idea.

Build your own projector.

[More Karma Than God]

Here's some links to previous Slashdot articles.

Homebrew Projectors

Light Sources

Enjoy!

It can be done very cheaply.

[gmiller123456]

You can use an old overhead projector with one of the LCD designed for use on a projector. Get a TV tuner for the computer and you've also got a large screen projection TV. I've also heard of people using a Fresnel lense to project the image of a monitor or TV, but you'll probably end up with a very dim image.

Re:It can be done very cheaply.

[merlin_jim]

I've used a fresnel lens. A couple notes:

Use a small CRT. 13" or so. Not only are these cheap (used), they're what the fresnel is designed for. The bigger the screen is compared to the fresnel, the less distinct it'll be.

Turn brightness all the way up, right up to the edge of getting pixel bleed

Don't project more than a couple feet... beyond that it's too dim to be daylight readable...

I use this in my MAME arcade machine... 13" lcd projecting onto smoked glass. It works pretty good, especially with the arcade machine not having any direct light on it (it's in a corner of my living room, approximately 5 feet away from the sliding glass doors along the same wall) For the smoked glass, I started with snow frosting you can find in art stores around christmas time, but moved to acrylic sanded with 240 grit sandpaper. The higher the grit the better resolution you get...

Would probably be fairly easy to build...

[cr0sh]

Actually, by far the best way to do a "countertop video display" is a recessed LCD - get an old laptop, extend the wires to the LCD, mount the CPU out of the way somewhere (in the cabinet, or on the rear wall - just make sure you can get to it), and put the LCD in a hole cut in the countertop. Rabbet the edge of the hole with a router so you can recess a piece of glass or similar material over the LCD. Add gasket material to seal out moisture (clear or custom-colored silicone would probably be best). Want to make it truely sweet? Add "pointer" capability - put pressure sensitive resistive strain gauges at the corners of the recess, and in the middle of the edges, prior to gluing the glass down. Run wires from these to the computer (think voltage divider connected to A/D converter - you could probably hack something up that connects to the serial port). Now, when you press on the glass, resistance of the strain gauges change, indicating where your finger is (because each has a different pressure registered). Custom software would have to be written to convert these eight values into X/Y coordinates (probably some simple averaging routine, along with a noise reduction algorithm). Finally, add code to detect single and double taps for selection use, then interface all of that with your GUI or text display.

But, if what you *really* want is a projector...

First, think about the color of the surface you are projecting on - notice that in the image you provided, the surface was dark, and the image was *very* bright. In fact, just from the picture I think it was too bright, it would probably dazzle you to actually use it in real life. A projector may or may not work well on such a surface, unless the image it was projecting had mostly light colors (whitish). Otherwise, you would want your surface to be something lighter (like a tan or grey color) - which may mean changing your countertop.

Once that issue is out of the way, all you have to do is build the projector (easier said than done, BTW). A simple projector is nothing more than an image source, and a convex (magnifying) lens. Simple "project-a-picture" projectors found at arts/crafts supply stores use this system. It works OK, but isn't the best (see numerous examples online and on ebay about 100 inch TV plans) - but may work well for your application. If you really want to do this right, look up information and discussion about "triplet projection lenses" - these are lens systems that are designed for projection, and tend to have everything set up to make the image projected clear and undistorted. Unfortunately, you will tend to find new triplet assemblies to be rather pricey - which is where surplus comes in. There are people out there building such projectors (for TV projection mainly) - the projectors thus built tend to be big, but in a theater-type setting, it doesn't matter as much (other than asthetics). But this is because the builders are trying to get a huge picture, and so need a lens with a large focal length, which increases the size of the projector (unless you are adept with mirrors and folding the light path - which is outside the scope of most builders). However, since you would be projecting a much shorter distance, you can get away with a smaller lens, and hence a smaller enclosure for the projector you build.

Here are a couple of sites to get you started:

Alan's DIY Projector

Apogee, Inc.

The first one is a guy who sells triplet lenses on eBay, but provides the plans and such for free. The second is a source I found for surplus lenses, and they have a few low focal length lenses that might fit the bill for what you are wanting to do. It also might be possible to build your own custom triplet assembly from lenses picked out of an Edmund Scientific catalog, but it will be pricey.

For an LCD, to keep the size down, use something like a smaller 5 or 6 inch LCD - these can be found surplus, or you can use something like that used for "in-dash" auto video systems. You will have to disassemble the LCD in order to add a bright backlight system (which is a whole discussion in and of itself - look at the sites off of Alan's links and you will see what has been tried, and how well it works - don't forget about heat issues and the LCD, too!). Hook up a VGA to TV converter, stick to a low-res display with larger fonts, and you are set.

Mouse pointer issues can be a problem here, but I would suggest a variation on what I described first, except instead of a clear glass inset in the counter, get a white or light color porcelain (ok, I I think I mangled that word) cutting "board", make the rabbets wider to hold the board better, and install a stainless steel "splash guard" around the seam, and seal it. Project down onto this. It can act as a "screen", and serve as a useful cutting board for cooking (ok, I am thinking "kitchen computer" here - where it seems the picture you provided was aimed at). Otherwise, inset a light panel of similar countertop or desk material instead.

I hope this helps - sometimes I wonder why I am not paid for this...

Why not just throw out your counter space?

[splattertrousers]

If you are projecting a recipe on the counter, then you can no longer use the counter. Don't tell me you'll be able to read the recipe if it's being projected onto clumps of flour, a box of eggs, a jar of sugar, a head of lettuce and a bottle of beer.

Perhaps a much easier and usable solution would be to put an LCD in the wall behind said counter, or in the door of the cabinet above said counter.

Of course, it wouldn't be very Microsoft-y, but you could hire someone to come into your kitchen from time to time, kick you out for a few minutes and remove the entire contents, requiring you to spend the rest of the day re-installing your kitchen. It would be great fun for people who don't like to cook (kind of like how Windows is great fun for people who don't actually want to use their computers to do work).

(Hmm... I wonder why I felt like bashing Microsoft so much this morning. Maybe the eggs I put in my lettuce-and-beer-cookies last night were bad.)

Do You Really Want This?

[nathanh]

I don't know about anyone else, but I know that when I'm cooking the entire bench space is covered in cutting boards and bowls and ingredients and so on. A top-down projector onto the bench space would be unreadable because the "screen" isn't flat anymore! I thought the idea looked pretty stupid when I read the "Microsoft House of the Future" article. I can't imagine why you'd want one!?

Prototype system from about 1990

[adam arndt]

Can any of you recall a prototype system which I have a hazy memory of seeing in a doco about user interface design around 1990-1992?

It featured a pretty amazing system I have never heard or seen anything of since. It went like this:

Computer and ceiling-mounted vid shoots on to white table top with standard windowing desktop image.

User moves arm and hands to "click" (touch) and "drag" (move finger) the icons. An image processing system via a camera (also in roof) does the differencing between the projected image and the captured image of the desk to get arm, finger movements.

They dude also "pulled up" a "virtual keyboard" and typed away. This was the image of a keyboard.

It got pretty out of hand when he put a real book on the desktop, then used two fingers to "select" a paragraph of text (system shaded a rectangle over the real book page!) and then he "dragged" this off into a virtual document!

It was a mock-up, but they asserted that the controlled arrangement of being able to difference the images would allow this kind of OCR and other interface stuff with current technology (early 90's).

It's pretty hysterical to watch.

Anyone heard of this?