1. Developments towards scanning optical microscopy

1.1 Television combined with microscopy

For televisual observation, which is commonly used in microscopy, the television camera takes the image provided by the microscope in a similar way to photography (cf. § 4.3 of article R 6 710. In general, a lens set to infinity behind the eyepiece forms an image on the photosensitive surface of a vidicon-type scanning tube [or on a CCD (Charge Coupled Devices) mosaic]. The electrons emitted by this photocathode, focused on a target (or stored in each element of the mosaic), create an electric charge distribution analogous to that of the illumination in the optical image. The analog signal obtained by reading the target (or discharging the capacitors in each mosaic element) scanned line by line is used to modulate the inscription electron beam...