Patent ID: 7696462

Claim:
An image intensifier for use in a night vision system, the image intensifier comprising: a power supply circuit having a reference voltage and configured to provide: a screen voltage maintained at a substantially time-invariable direct current value, a microchannel plate input voltage switching between a maximum value and a minimum value, a microchannel plate output voltage maintained at a substantially time-invariant direct current voltage with respect to the microchannel plate input voltage, and switched in phase with the microchannel plate input voltage, and a photocathode voltage maintained at a substantially time-invariable direct current value; a photocathode receiving the photocathode voltage from the power supply circuit; a microchannel plate coupled to the photocathode and receiving the microchannel plate voltage from the power supply; and a screen coupled to the microchannel plate and receiving the screen voltage from the power supply; whereby the photocathode provides shielding against electromagnetic interference caused by switching of the microchannel plate voltage.