Abstract A field emission cathode capable of permitting a voltage required for starting emission of electrons from the emitters to be decreased and the emission to be rendered uniform. The field emission cathode includes cathode electrodes formed on a substrate. On each of the cathode electrodes are arranged a plurality of emitters through diodes each acting as a constant-current element, and gate electrodes are arranged above the emitters. Arrangement of the diodes between the emitters and the cathode electrode permits a drive voltage to be reduced as compared with arrangement of a resistive layer therebetween, because a diode is generally decreased in voltage drop as compared with the resistive layer. Also, the arrangement renders emission of electrons from each of the emitters uniform.
A field emission cathode comprising: an insulating substrate; cathode electrodes arranged on said substrate; constant-current elements provided on said substrate; emitters arranged on said substrate and connected through said constant-current elements to said cathode electrodes; insulating layers formed on said cathode electrodes having holes in the vicinity of said emitters; and gate electrodes arranged on said insulating layers in a manner to be positioned around said emitters.
Claim 2
Dependent Claim
67 words
A field emission cathode comprising: an insulating substrate; cathode electrodes arranged on said substrate; constant-current elements provided on said substrate; emitters arranged on said substrate and connected through said constant-current elements to said cathode electrodes; insulating layers formed on said cathode electrodes having holes in the vicinity of said emitters; and gate electrodes arranged on said insulating layers in a manner to be positioned around said emitters.
Claim 3
Dependent Claim
28 words
A field emission cathode as defined in claim 1, wherein said constant-current elements comprise diodes including metal layers made of gold and semiconductor layers made of amorphous silicon.
Claim 4
Dependent Claim
26 words
A field emission cathode as defined in claim 2, wherein said diodes are formed by directly joining semiconductor layers and said cathode electrodes to each other.
Claim 5
Dependent Claim
29 words
A field emission cathode as defined in claim 1, wherein said constant-current element comprises a field effect transistor and a resistor formed between said cathode electrode and said emitter.
Claim 6
Dependent Claim
23 words
A field emission cathode as defined in claim 1, wherein said constant-current element comprises a constant-current circuit constructed using a plurality of transistors.