TubeTime

You’ve probably seen LCD displays that use electroluminescent panels for the backlight. They’re not so common since the advent of the white LED, but they were used all the time for those 5×7 character displays. Wikipedia has a nice article about electroluminescent technology.

Well, it turns out they can be used to make displays:

Here’s a closeup of the pixels:

The “ghostly” numbers are letters are the result of the screen displaying the same thing for years and years. Looks like it was from a machine used for rapid thermal processing of semiconductor wafers.

This display panel was made by Finlux. There’s a very thorough history of this company and EL displays here: http://www.indiana.edu/~hightech/fpd/papers/ELDs.html.

It’ll be fun coming up with a project for this one. The display is 640×200, “high resolution” CGA. The video inputs are TTL-level video, hsync, vsync, and pixel clock. It will probably work at other frequencies too since the panel just uses high-voltage shift registers, not some special video ASIC. The tricky part will be getting the pixel clock to the device since video card connectors don’t provide that. Maybe I’ll just drive it with a microcontroller…