Direct view thermal tube?

[Ultrapurple]

I came across this abstract:

Describes the pyroelectric electron mirror tube, which is a thermal imaging tube working in the 8-14 mu m band of the infrared. The principle of operation is that an image of the thermal scene is formed on a pyroelectric target and a representation of the resulting voltage pattern is formed on a phosphor screen using the principle of the electron mirror. This results in a direct-view tube requiring no mechanical scanning, cryogenic cooling, or TV circuitry.

(Journal of Physics D: Applied Physics : A direct-view thermal imaging tube : H A H Boot, J G Castledine, P G R King, K E Trezise and B Turner : Published 1 April 1976)

Leaving aside for a moment the unfortunate publication date, the abstract implies to me a tube not unlike a Gen 0 night vision device but with a pyroelectric photocathode. Google found an intriguing image:



Does anyone know any more about this, or possibly even have access to the original 1976 article?

[Fraser]

I have that article 

I will send it to you later today

Fraser

[Bill W]

Somewhat before my time, but it was an attempt as you say at a thermal image intensifier.  It did not work very well, and the disadvantages of the bulky discrete electronics for the vidicon camera approach rapidly reduced.
This is what 'reduced' meant though...


A similar concept was promoted by 'RedShift' much more recently where again a thermal sensitive array affected a visual system, in the RedShift case a CCD camera.  They called it a TLV - Thermal Light Valve
https://www.techbriefs.com/component/content/article/tb/techbriefs/photonics/12142
RedShift also did not make it iff the bench, may even have been a scam, but kept a few folks off the streets for a few years.

[Ultrapurple]

Is that white tank the liquid nitrogen reserve? 

(Yes I know it was an uncooled camera, but even so...)

[Ultrapurple]

And the look on that chap's face reminds me of this marvellous (if now politically-incorrect) sketch:

[Fraser]

As Ultrapurple has said to me offline, I am surprised that a wavelength converter for thermal wavelengths did not progress further in Military circles. I say this because the infrared wavelength converters and image intensifiers did undergo great development for military applications and grew more capable as a result. A pyroelectric thermal wavelength converter that was like the modern military image intensifier units with high gain figures would have been an interesting development. Resolution would be dictated by target and phosphor grain and any micro channel amplification stages, if used. Imagine making a high resolution converter that you could bolt onto a high resolution modern SLR camera ! Such exists for image intensification and IR. An example being the Electrophysics Astroscope of which I own a Gen 3 example 

Fraser

[Flukav]

Reminds me of this great scope-looking passive thermal imager:
https://benkrasnow.blogspot.com/2010/10/low-cost-diy-thermal-imaging-liquid.html

[Lambda]

Hello...

Sorry for digging here... But while, as a newcomer, enjoying to drift through the forum, i was falling on this topic.
I am also interested in this version of thermal viewer, being already a user of standard (Vis/NIR) image intensifiers integrated in some DIY projects.

To see IRL a thermal gear based on this elegant concept, would be really enjoyable for me....

While waiting this time coming, i found a published patent disclosing such concept, based on a standard architecture of a modern image intensifier including MCP.

https://patents.google.com/patent/US10062554B2/en

The main difference was the photocathode composition. Here is claimed the use of some "metamaterial" having a specific composite structure and exhibiting electron emissivity when submitted to LWIR radiation, instead of using the usual Vis/NIR responsive GaAs or Alkali/multi-Alkali material...

Promising (IMHO)...

Cheers.

Stéphane

[Bill W]

Here's another 

https://www.techbriefs.com/component/content/article/tb/supplements/ptb/briefs/12142

The Redshift 'Thermal Light Valve', as far as I know falling somewhere between vapourware and unicorn poo.

Bill

[adammunich]

I am interested in reading it too!