Raspberry Pi Transparent Displays openFrameworks

Client MTID, Employer CMU

December 2014

A multi-layer display

LAYERd is a multi-layer display made from off-the shelf computer monitors. It allows for glasses-free 3D as well as a novel way to envision User Interfaces.

It was created as part of my masters degree program at CMU in Making Things Interactive. A more complete write-up is available here.

Every LCD screen on the planet is made of two main parts: a transparent assembly (made of laminated glass, liquid crystal, and polarizing filters) and a backlight. Without the backlight, an LCD monitor is actually completely transparent wherever a white pixel is drawn.

LAYERd uses three of these LCD assemblies illuminated by a single backlight to create a screen with real depth: objects drawn on the front display are physically in front of objects drawn on the rear ones.

My work is mainly focused on the potential UI uses for such a display: what can one do with discrete physical layers in space?

Here, you can see how the glass panel is transparent, and how the backlight illuminates it.

The process begins by disassembling the three monitors. After destroying two cheaper ones with static electricity before the project began in earnest, I was very careful to keep the delicate electronics grounded at all times, and I worked on top of an anti-static mat and used an anti-static wristband when possible.

I learned a lot about polarization; mainly that about half of the films needed to be removed in order for light to pass through the assembly. Plus, this cool little trick with polarized light.

I also learned about safety/how monitors work: I accidentally cut one of the ribbons while disassembling a monitor, which resulted in a single vertical stripe of dead pixels.

Plus, my front display got smashed a little bit on the way to the gallery show, and made a black splotch.

This project was supported in part by funding from the Carnegie Mellon University Frank-Ratchye Fund For Art @ the Frontier.