Image intensifier with improved input screen

Claim 2

A fluorescent screen for use with and sensitive to a selected exciting radiation incident thereon, which radiation has known penetration depth values with respect to known fluorescent materials, comprising a layer embodying a multiplicity of rods of selected fluorescent material extEnding in parallel relation through the thickness of the layer, the layer being of a thickness which will absorb at least 50% of the selected exciting radiation impinging thereon, and means for preventing transconductance of fluorescence between rods.

Claim 3

A fluorescent screen as set forth in claim 1 wherein said means comprises a reflective coating on said rods and each of said rods is covered by a light-transparent sheath within said reflective coating.

Claim 4

A fluorescent screen as set forth in claim 1 wherein said parallel rods are of a thickness ranging about from 0.010 inch to 0.100 inch and are spaced sufficiently close enough to produce a resultant light picture of the order of from 0.3 to three line pairs per millimeter.

Claim 5

A fluorescent screen as set forth in claim 1 wherein the rods are cesium iodide activated with tellurium.

Claim 6

A fluorescent screen as set forth in claim 1 wherein the rods are cesium iodide activated with sodium.

Claim 7

A fluorescent screen as set forth in claim 1 wherein the rods are silicon iodide activated with thallium.

Claim 8

A fluorescent screen as set forth in claim 1 wherein the rods are lithium iodide activated with europium.

Claim 9

A fluorescent screen as set forth in claim 1 wherein the rods are potassium iodide activated with thallium.

Claim 10

A fluorescent screen as set forth in claim 1 wherein said layer is of a thickness which will absorb at least 90 percent of the selected exciting radiation impinging thereon.

Claim 11

A screen assembly for an electron tube, comprising a fluorescent layer embodying photon-emitting material sensitive to a selected exciting radiation incident thereon which radiation has known penetration depth values with respect to known fluorescent materials, and a photoemissive layer adjacent the fluorescent layer capable of electron emission in response to impingement of photons from the fluorescent layer, said fluorescent layer comprising a multiplicity of rods of selected fluorescent material extending in parallel relation through the thickness of the layer, the thickness of the fluorescent layer being substantially equal to the maximum penetration depth of the selected exciting radiation in said selected fluorescent material, and reflective means surrounding each rod for preventing transconductance of fluorescence between rods.

Claim 12

A screen assembly for an electron tube, comprising a fluorescent layer embodying photon-emitting material sensitive to a selected exciting radiation incident thereon which radiation has known penetration depth values with respect to known fluorescent materials, and a photoemissive layer adjacent the fluorescent layer capable of electron emission in response to impingement of photons from the fluorescent layer, said fluorescent layer comprising a multiplicity of rods of selected fluorescent material extending in parallel relation through the thickness of the layer, the thickness of the fluorescent layer being substantially equal to the maximum penetration depth of the selected exciting radiation in said selected fluorescent material, and reflective means surrounding each rod for preventing transconductance of fluorescence between rods.

Claim 13

A screen assembly as set forth in claim 10 wherein each of said rods is covered by a light-transparent sheath with said reflective means.

Claim 14

A screen assembly as set forth in claim 10 wherein said parallel rods are of a thickness ranging about from 0.010 inch to 0.100 inch and are spaced sufficiently close enough to produce a resultant light picture of the order of three line pairs per millimeter.

Claim 15

A screen assembly as set forth in claim 10 wherein the photon-emitting material is cesium iodide activated with tellurium.

Claim 16

A screen assembly as set forth in claim 10 wherein the photon-emitting material is cesium iodide activated with sodium.

Claim 17

A screen assembly as set forth in claim 10 wherein the photon-emitting material is silicon iodide activated with thallium.

Claim 18

A screen assembly as set forth in claim 10 wherein the photon-emitting material is lithium iodide activated with europium.

Claim 19

A screen assembly as set forth in claim 10 wherein the photon-emitting material is potassium iodide activated with thallium.

Claim 20

A screen assembly as set forth in claim 10 wherein a light-reflecting layer transparent to said incident radiation is disposed adjacent the surface of the fluorescent layer which is directed toward the incident radiation.

Claim 21

A screen assembly as set forth in claim 10 wherein a thin light-transparent barrier layer is disposed between the photoemissive layer and the adjacent ends of the rods.

Claim 22

An image intensifier tube comprising an envelope having an input screen at one end and an output screen at the opposite end, said input screen comprising a fluorescent layer embodying scintillation material sensitIve to a selected exciting radiation incident thereon, which radiation has known penetration depth values with respect to known fluorescent materials, and a photoemissive layer adjacent the fluorescent layer capable of electron emission in response to impingement of photons from the fluorescent layer, said fluorescent layer comprising a multiplicity of rods of selected fluorescent material extending in parallel relation through the thickness of the layer, the thickness of the fluorescent layer being substantially equal to the maximum penetration depth of the exciting radiation in said selected fluorescent material, reflective means surrounding each rod for preventing transconductance of fluorescence between rods, electrodes in the envelope between said screens, and means for applying potentials to said electrodes for accelerating and focusing electrons from said photoemissive layer onto said output screen.

Claim 23

An image intensifier tube comprising an envelope having an input screen at one end and an output screen at the opposite end, said input screen comprising a fluorescent layer embodying scintillation material sensitIve to a selected exciting radiation incident thereon, which radiation has known penetration depth values with respect to known fluorescent materials, and a photoemissive layer adjacent the fluorescent layer capable of electron emission in response to impingement of photons from the fluorescent layer, said fluorescent layer comprising a multiplicity of rods of selected fluorescent material extending in parallel relation through the thickness of the layer, the thickness of the fluorescent layer being substantially equal to the maximum penetration depth of the exciting radiation in said selected fluorescent material, reflective means surrounding each rod for preventing transconductance of fluorescence between rods, electrodes in the envelope between said screens, and means for applying potentials to said electrodes for accelerating and focusing electrons from said photoemissive layer onto said output screen.

Claim 24

An image intensifier tube as set forth in claim 20 wherein each of said rods is covered by a light-transparent sheath within said reflective means.

Claim 25

An image intensifier tube as set forth in claim 20 wherein said parallel rods are of a thickness ranging about from 0.010 inch to 0.100 inch and are spaced sufficiently close enough to produce a resultant light picture of the order of three line pairs per millimeter.

Claim 26

An image intensifier tube as set forth in claim 20 wherein the scintillation material is cesium iodide activated with tellurium.

Claim 27

An image intensifier tube as set forth in claim 20 wherein the scintillation material is cesium iodide activated with sodium.

Claim 28

An image intensifier tube as set forth in claim 20 wherein the scintillation material is silicon iodide activated with thallium.

Claim 29

An image intensifier tube as set forth in claim 20 wherein the scintillation material is lithium iodide activated with europium.

Claim 30

An image intensifier tube as set forth in claim 20 wherein the scintillation material is potassium iodide activated with thallium.