Transparent / Opaque Glass Controller


Automatic Control of Video Projectors and Electronic (LC) Glass Panels.

[click to enlarge]


We were approached by a client who was designing a booth for a large trade show. Portions of the booth walls were made from panels of LC Glass – a nifty product which normally appears to be clear glass.

However, when an electrical control signal is applied, it turns a frosty white transluent color. Light passes through, but ithe panel is optically opaque. High-end builders use it in expensive houses. Just flip a switch to go from a stunning view of the lake to light-filled privacy.

This client wanted to rear-project video onto this glass from time to time throughout the trade show. Passers-by could alternately view video clips or peer into the booth, depending on the state of the electronic glass.

Their booth contained three video screens fabricated from these LC Glass panels and each screen was fed by a 6500 lumen Panasonic video projector. The projectors each included an internal lens shutter, which can be controlled through the projector’s serial port.

To project video, the glass is energized (turning it opaque) and the projector shutter is opened. When the video clip is finished, the projector shutter closes and the glass is de-engerzied.

Our interface solution works as follows:

The system includes a -10 dB line-level audio input jack. When a standard 1 KHz tone is received, the proper serial signals are transmitted through each of the system’s three serial ports. Also, an internal relay closes, allowing the control signal to reach the LC glass.

When a short 3 KHz tone is received, the process is reversed and the glass returns to the clear state.

The client simply recorded program audio on one channel of their looping DVD and short bursts of tone on the other channel. Thus, the display could run automatically throughout the day with no further user input.

Last we heard, the system had been used successfully at two high-intensity trade shows.

Warm Fuzzies From the Field:

“Engineering Solutions. The name says it all.

I had a particularly interesting staging challenge to overcome. It involved synchronizing the shutter control of three projectors via serial cable with the triggering of a power relay in order to pull off an interesting effect. It was, indeed, an Engineering challenge.

The Solution came through consultation with John Chapman. I found him on in the Wild West of the internet and had nothing to go on other than someone else’s written testimony. Now here is mine.

Chapman is a fellow who listens, thinks before he speaks, and when he does speak, he tells you first what he heard you say so you know he understands exactly what you’re trying to achieve, then, when he speaks, you get the good stuff: a series of options which make sense. The conversation then follows logically as you evolve the concept in partnership.

A prototype controller was delivered to me in New York ahead of schedule. It was a beautifully constructed and engineered piece, built to professional grade. After testing I located firmware issues that needed addressing and returned the piece for adjustment. Again, John, was thorough in his analysis and resolved the issues directly.

The exhibit (part of a high-dollar pitch) ran for 4 days continuously without one hitch. It was nothing but a satisfying pleasure to work with this man. A great result. The fee charged for all this original work was more than reasonable. Try to throw him a bigger challenge – I get the feeling he enjoys his work!”

– Quentin, CCG Metamedia, NY


If you’d like something similar, just let us know. We’re always on the lookout for groovy little niche designs like this. Turnaround time is speedy and our pricing is very reasonable.

 Posted by at 4:41 am