Infographics / Fluoroscopy

TV camera tube / CCD readout of the II output

The image-intensifier output phosphor is coupled by a lens or fibre optics to a TV camera. Inside a camera tube (vidicon or Plumbicon) light falls on a photoconductive signal plate behind a mesh anode; a heated cathode emits an electron beam that magnetic focus and deflection coils sweep across the target line-by-line, giving a voltage proportional to local light intensity. A solid-state CCD is the alternative. The target is read out as a raster of scan lines, either interlaced (two fields per frame) or progressive, at roughly 625 lines per frame and 25 to 30 frames per second.

Fluoroscopy TV-camera read-out chain The image-intensifier output phosphor is coupled by a lens or fibre optics to a TV camera. Inside a camera tube (vidicon or Plumbicon) light falls on a photoconductive signal plate behind a mesh anode; a heated cathode emits an electron beam that magnetic focus and deflection coils sweep across the target line-by-line, giving a voltage proportional to local light intensity. A solid-state CCD is the alternative. The target is read out as a raster of scan lines, either interlaced (two fields per frame) or progressive, at roughly 625 lines per frame and 25 to 30 frames per second. Fluoroscopy TV-camera read-out chain image intensifier output phosphor lens or fibre-optic coupling TV camera (tube or CCD) digital video, ~25–30 fps to processor & display inside a camera tube (vidicon / Plumbicon) light from coupling mesh anode focus & deflection coils heated cathode (thermionic emission) electron beam scans target line-by-line (raster) signal plate: photoconductive target on conductive (graphite) backing output voltage ∝ local light intensity → video signal solid-state CCD is the alternative: no scanning beam, ~25–30 fps read-out, low lag, magnetically stable raster read-out of the target: scan lines per frame & frame rate interlaced two interleaved fields (odd + even) = one frame progressive all lines in one top-to-bottom pass ≈625 lines per frame (PAL); ≈25–30 frames per second
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