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US 5,917,277 AGranted
Electron source including a perforated permanent magnet
AssigneeInternational Business Machines Corporation
InventorsAndrew Knox, John Beeteson
Life of this patent
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Abstract
An electron source having a cathode and a permanent magnet having perforated channels extending between opposite poles of the magnet. Each channel forms electrons received from the cathode into an electron beam for guidance towards a target. The electron source has applications in a wide range of technologies, including display technology and printer technology.
Claims32
An electron source comprising a cathode;
- a permanent magnet block perforated by a plurality of channels, each channel having a length larger than its width and extending between opposite poles of the magnet block, wherein, in each channel, a magnetic field acts upon electrons received from the cathode for a sufficient time to form an electron beam for guidance towards a target;
- and grid electrode means disposed between the cathode and the magnet block for selectively addressing different ones of the channels to control flow of electrons from the cathode towards the target through the selectively addressed channels.
A display device comprising:
- an electron source having cathode means, a permanent magnet perforated by a plurality of channels extending between opposite poles of the magnet wherein each channel forms electrons received from the cathode means into an electron beam for guidance towards a target, arid electrode means disposed between the cathode means and the magnet for selectively addressing different ones of the channels to control flow of electrons from the cathode means towards the target through the selectively addressed channels, and anode means disposed on the surface of the magnet remote from the cathode for accelerating electrons through the channels;
- a screen for receiving electrons from the electron source, the screen having a phosphor coating facing the side of the magnet remote from the cathode;
- and
- means for supplying control signals to the grid electrode means and the anode means to selectively control flow of electrons from the cathode to the phosphor coating via the channels thereby to produce an image on the screen.
1 more element
A display device comprising:
- an electron source having cathode means, a permanent magnet perforated by a plurality of channels extending between opposite poles of the magnet wherein each channel forms electrons received from the cathode means into an electron beam for guidance towards a target, grid electrode means disposed between the cathode means and the magnet for selectively addressing different ones of the channels to control flow of electrons from the cathode means towards the target through the selectively addressed channels, and anode means disposed on the surface of the magnet remote from the cathode for accelerating electrons through the channels;
- a screen for receiving electrons from the electron source, the screen having a phosphor coating facing the side of the magnet remote from the cathode, the phosphor coating comprising a plurality of groups of different phosphors, the groups being arranged in a repetitive pattern, each group corresponding to a different channel;
- means for supplying control signals to the grid electrode means and the anode means to selectively control flow of electrons from the cathode to the phosphor coating via the channels;
- and
- deflection means for supplying deflection signals to the anode means to sequentially address electrons emerging from the channels to different ones of the phosphors for the phosphor coating thereby to produce a color image on the screen.
2 more elements
Dependencies are inferred from the claim text.