# Need help finding this...



## okenigi (Jun 17, 2013)

I have a project of making something like a batman spotlight sign but instead of batman logo projected into the sky, it will be my restaurant logo instead projected to the wall. I have no idea how to do that or what r the things i need to make my project happen. Please help me. Thank you in advance.


----------



## jspeybro (Jul 4, 2013)

You typicaly need a lot of light, which is then projected in a small area. The logo will take a part of the projected light away to form the logo on tha wall.
Easiest way of making such a projector is to use a high power LED with an aspheric lens or a short focal length lens wich is slightly defocussed to give a nice and evenly distributed light circle.
If you print the logo on a transparant plastic layer, you can then put it in front of your lens. 
I don't know if a single LED will be powerfull enough for your application. The most powerfull LEDs out there are 100W LED arrays, but these are difficult to focus. Its better to look at the Cree XML or SST-90 LEDs.
THere are some nice examples of setups with different (sets of) lenses on the forum.

If LED is not sufficient, it gets a bit more complicated. You'll need an HID bulp or something similar to increase the light output, but this also creates heat so you'll need to take care of that where you want to place the logo (or make the logo in a heat resistant material).

I have fresnel lenses I can offer if you're interested.

Johan


----------



## Ken_McE (Jul 11, 2013)

There are existing devices that may fill your need. There are projectors used in schools that are a square box with a light in it and an arm hanging over the box. You lay your transparency on the box and it is displayed up on the wall. 

There are newer devices that you plug into a computer and then it projects whatever is on the computer up on a wall.

You might take an old movie projector and adapt it to only show your logo.

All of these devices have high powered bulbs and work better in the dark. Do you have a smooth reflective surface to light up with your machine?


----------



## SemiMan (Jul 14, 2013)

Lots of off the shelf units to do this. Likely cheaper in the long run.

Semiman

Sent from my Nexus 4 using Tapatalk 4 Beta


----------

