Patent ID: 7088048

Claim:
Device for switching and controlling an electron dose emitted by a micro-emitter, characterized in that it comprises: a sensor module that receives the output current from the micro-emitter and a voltage to adjust the polarization point of the said device, a comparator module that receives the output signal from the said sensor module, and a threshold voltage to adjust the quantity of electrons to be emitted, a logical module that receives the output signal from the comparator module, and a start signal to initialize the electron emission, and a logical signal to define whether or not the micro-emitter should emit, a control module that receives the output signal from the said logical module that generates the voltages necessary for initialization and extinction of the micro-emitter current pulse, means of varying the threshold voltage such that the sum S=N start +N measure +N off remains substantially constant during the electron emission, where N start is the number of electrons at the current pulse start time, N measure is the number of electrons at the measurement time of this current pulse, and N off is the number of electrons at the extinguishing time of this current pulse.