Gas discharge viewfinder backlight

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I found this interesting gas discharge panel in an old Canon camcorder viewfinder (1999 vintage MV20i).  Does anyone know what they are called?

Mike found one in his fire brigade Flir thermal camera repair video but not seen anything about them on the internet apart from that.

It seems to power up with a supply of 3.3v and an approx 24kHz square wave on the 3rd pin.  Not sure if this is a PWM for dimming or just a dumb square wave input.

This was attached to another PCB that contained the LCD driver.

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Looks like a flat CCFL.

[SeanB]

Is it a Panaplex panel or an electroluminescent one?  Looks more like it is an electroluminescent one, driven with around 100VAC at a few kHz.

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I'm not sure - I don't think it's Panaplex as that was neon I believe. 

This looks more like EL or fluorescent.  The lamp itself only has 2 leads so maybe some kind of flat CCFL type device?  EL has always appeared dim to me but that is the wire I am referring to and only the cheapie stuff.

I see references to FFL or 'flat fluorescent lamp' in old LCD backlight papers so maybe that's what it is.

[Fraser]

It is a flat fluorescent lamp. Very common in colour EVFs before OEMs moved to LED backlights. I bought a whole load of SVHS camcorders off eBay just to obtain the backlight panel and driver. They are often a cause of dim EVF in the thermal cameras that I repair. Hard to source as a spare part these days.

Fraser

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Cheers Fraser thanks for that info.

Though they were probably the best fit at the time these days they are pretty inefficient - this lamp draws 0.5A at 3.3V!  It's only as bright as a modern white LED.

This viewfinder was on a camera that had an LCD fold out display (which itself used a CCFL) so this FFL hasn't been used a great deal.

Will find a suitable project that needs it and put it in that!

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Some interesting reading on FFLs - though this concentrates on larger lamps but I suspect it's somewhat similar.

https://books.google.com.au/books?id=Ae9GREa9ozsC&pg=PA150&lpg=PA150&dq=ffl+voltage&source=bl&ots=NcznKIoqFB&sig=7ULqmZq54mr-7F4s8uM74bU2Nb8&hl=en&sa=X&ved=0CEQQ6AEwCWoVChMI_beO1pW-yAIVWI-OCh3e_Qa2#v=onepage&q=ffl%20voltage&f=false