How did the Nipkow disk function at the transmitting end of Baird's system?

Answer

It captured tiny vertical slices of the image via spinning holes

As the disk rotated, each hole momentarily captured a small vertical segment of the focused scene, which was then scanned across a photoelectric cell to convert the light information into electrical signals.

How did the Nipkow disk function at the transmitting end of Baird's system?
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