Flat panel displays, anyone?

[Stephen]

Mr Baird proposed and developed successful flat panel displays at an early date. In fact, Mr. Baird demonstrated such a display panel using 30 rows of 70 miniature flash lamps at the London Coliseum three times per day starting on 28 July 1930 for a fortnight. It had a billing of the first public presentation of television in any theatre. According to reports at the time, it worked quite well.

He always used incandescent lights for the picture elements. The decay time of the lights helped to reduce apparent flicker, much like a phosphorescent screen.

Mr Baird developed a fairly extensive patent portfolio relating to such displays, including his first filed television patent, British Patent 222,604, filed 26 July 1923, a copy of which is in the Patent and Articles section. I have also uploaded the other flat panel display patents of which I am aware in the Patents and Articles section. These are 302,187; 347,254; 347,741; 348,211; and 359,981. The 359,981 patent is also interesting in that Mr Baird describes a dot-sequential colour television embodiment that is the precursor to both NTSC and PAL colour television systems.

It would be interesting to see a re-creation of such a flat panel display. Mr Baird's technology also blurs the line between so-called "mechanical" and "electronic" television, which terminology is misleading and imprecise in my opinion. Clearly, all of Mr Baird's flat panel displays have pixel addressing by electrical means, just like present day flat panel displays. The fact that he had to resort to high speed electromechanical commutation instead of valve or semiconductor electrical commutation for such electrical pixel addressing is patentably indistinct. Referring to such a display system as mechanical would be as appropriate as referring to a PC with a hard drive as a mechanical computer. Likewise, a DLP television display is mechanical in the sense that is has moving mirrors.

Instead, it is more correct to catagorise television systems by whether they scan by optical addressing means or electrical/electronic addressing means. Clearly, scanning systems of the aperture/lens/mirror disc or drum type utilise optical addressing means, whereas cathod ray devices and flat panel transducers with fixed arrays of pixels utilise electrical/addressing means. Clearly Mr Baird proposed and developed devices of the latter type from the beginning of his research work.

End of rant.

[gary]

It would be interesting to see a re-creation of such a flat panel display.

There are a number of examples of flat panel displays implemented using led arrays and electronic commutation (e.g. Grant Dixon NL 20/3), but using incandescent lamps and mechanical commutation would be another matter I think! I had a dream of doing so in the late sixties after reading about his cinema demonstrations of same, alas, the sheer cost of the lamps was beyond me at the time (just as it is now .

[gary]

Having said that wouldn't it make a great living room feature?.

[AncientBrit]

There was a demo of a mechanically commutated display at the NBTV Convention about 6 years ago.

I think it was built by Dave Gentle.

Regards,

GL