Patent Number: 041692292
Section: claims

1. Apparatus for the keying in of electron beams for an electron beam system appropriate for a raster electron scan microscope, an electron beam recording apparatus and the like, comprising a deflection system for the deflection of the electron beam controllable in time for deflecting the beam out of its contemplated beam axis for beam scanning, the deflection system exhibiting a velocity modulating effect adapted to the beam velocity, characterized by the fact that the deflection system comprises a deflection installation (31, 32) having parts (33, 34, 51) symmetrical in relation to each other as related to the beam axis (15) at which the deflection signals are to be applied with opposite signs in each case, so that even with beam deflection a uniform axial potential remains. 2. The apparatus as defined in claim 1, with an apertured disk lens (16) arranged in the beam axis. 3. The operation of an apparatus for keying in electron beams as defined in claim 1, characterized by the fact that for a short-time keying in of electron beams with the use of comparatively broad impulses, impulses shifted in time in relation to each other are applied to the deflection installation which overlap in time only slightly (FIG. 4).