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US 4,070,574 AGranted
Magnifying image intensifier
OwnerJames C. Fletcher, James Vineinventors
Life of this patent
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Abstract
An improvement in a magnetically focused image intensifier for increasing the usable range of magnification without degradation of image quality and while keeping to a minimum the power requirements of the focusing coils. The improvement comprises an arrangement of focusing coils which reverses the direction of the axial magnetic field distribution between the planes of the photocathode and the phosphor screen.
Claims10
A magnetically focused image intensifier tube, comprising:
- photocathode means responsive to light radiation for emitting an electron beam;
- phosphorescent means axially spaced from said photocathode means for attracting said electron beam;
- first coil means surrounding said photocathode means and having an electrical current flowing therethrough in one direction, said first coil means providing a magnetic focusing field having a positive magnetic field strength at said photocathode means;
- and
- second coil means surrounding substantially all of said space between said photocathode means and said phosphorescent means and having said electrical current flowing therethrough opposite to said one direction, said second coil means providing a magnetic focusing field reversed from said magnetic focusing field of said first coil means between said photocathode means and said phosphorescent means and providing a negative magnetic field strength at said phosphorescent means for increasing the usable magnification range of said image intensifier tube without increasing the power consumption of said first and second coil means.
2 more elements
Dependencies are inferred from the claim text.