Dark field, high contrast light emitting display

Claim 2

A cathode ray tube according to claim 2 in which the light-absorbing layer consists essentially of a silicon oxide at the interface.

Claim 3

A viewing screen for a cathode ray tube, which screen is subjected to electrons from an electron gun in an evacuated environment, said viewing screen comprising: a transparent viewing portion; a light-transmissive, light-emitting phosphor layer on the interior surface of said viewing portion intended to face the electron gun; and a light-absorbing layer covering and adherent to the phosphor layer, whereby electrons from the gun cause the phosphor layer to emit light which is transmitted through the viewing region, and light transmitted toward the light-absorbing layer is substantially absorbed by the light-absorbing layer, said light-absorbing layer having an index of refraction substantially equal to that of said phosphor layer and formed to provide an intimate, contiguous and continuous transition at the interface of the phosphor layer and light-absorbing layer, whereby the substantial equality of the indices of refraction and the intimacy, contiguity, and continuity of the transition at the interface of the phosphor layer and the light-absorbing layer all contribute to minimize reflection of light which impinges on the interface of the two layers from the viewing side.

Claim 4

A viewing screen for a cathode ray tube, which screen is subjected to electrons from an electron guN in an evacuated environment, said viewing screen comprising: a transparent viewing portion; a light-transmissive, light-emitting phosphor layer on the interior surface of said viewing portion intended to face the electron gun; and a light-absorbing layer covering and adherent to the phosphor layer, whereby electrons from the gun cause the phosphor layer to emit light which is transmitted through the viewing region, and light transmitted toward the light-absorbing layer is substantially absorbed by the light-absorbing layer, said light-absorbing layer having an index of refraction substantially equal to that of said phosphor layer and formed to provide an intimate, contiguous and continuous transition at the interface of the phosphor layer and light-absorbing layer, whereby the substantial equality of the indices of refraction and the intimacy, contiguity, and continuity of the transition at the interface of the phosphor layer and the light-absorbing layer all contribute to minimize reflection of light which impinges on the interface of the two layers from the viewing side.

Claim 5

A viewing screen according to claim 4 in which the light-absorbing layer is substantially transparent at the interface, and in which a gradually increasing concentration of light-absorbing material is included as a function of the distance from said interface.

Claim 6

A viewing screen according to claim 4 in which the light-absorbing layer is substantially transparent at the interface, and in which a gradually increasing concentration of light-absorbing material is included as a function of the distance from said interface.

Claim 7

A viewing screen according to claim 5 in which the light-absorbing layer consists essentially of a silicon oxide at the interface.

Claim 8

A viewing screen according to claim 5 in which the light-absorbing layer consists essentially of a silicon oxide at the interface.

Claim 9

A viewing screen according to claim 4 in which a transparent electrode system is applied to the viewing side of the phosphor layer, and another electrode system on the opposite side of the light-absorbing layer from the viewing side.

Claim 10

A viewing screen according to claim 4 in which a transparent electrode system is applied to the viewing side of the phosphor layer, and another electrode system on the opposite side of the light-absorbing layer from the viewing side.

Claim 11

A luminescent device including a light-transmissive, light-emitting phosphor layer having a viewing side and an opposite side, and a light-absorbing layer coating said opposite side, said light-absorbing layer having an index of refraction substantially equal to that of said phosphor layer and formed to provide an intimate, contiguous and continuous transition at the interface of the phosphor layer and light-absorbing layer, whereby the substantial equality of the indices of refraction and the intimacy, contiguity and continuity of the transition at the interface of the phosphor layer and the light-absorbing layer all contribute to minimize at the interface of the layers reflection of light which has passed from the phosphor layer and impinged on the interface, the light-absorbing layer being light-absorbing in the sense that it admits said light which impinges on the interface of the layers from the viewing side and absorbs it.

Claim 12

A luminescent device including a light-transmissive, light-emitting phosphor layer having a viewing side and an opposite side, and a light-absorbing layer coating said opposite side, said light-absorbing layer having an index of refraction substantially equal to that of said phosphor layer and formed to provide an intimate, contiguous and continuous transition at the interface of the phosphor layer and light-absorbing layer, whereby the substantial equality of the indices of refraction and the intimacy, contiguity and continuity of the transition at the interface of the phosphor layer and the light-absorbing layer all contribute to minimize at the interface of the layers reflection of light which has passed from the phosphor layer and impinged on the interface, the light-absorbing layer being light-absorbing in the sense that it admits said light which impinges on the interface of the layers from the viewing side and absorbs it.

Claim 13

A luminescent device according to claim 8 in which the light-absorbing layer is polycrystalline.

Claim 14

A luminescent device according to claim 8 in which the light-absorbing layer is polycrystalline.

Claim 15

A luminescent device according to claim 8 in which the light-absorbing layer is substantially transparent at the interface, and in which a gradually increasing concentration of light-absorbing material is included as a function of the distance from said interface.

Claim 16

A luminescent device according to claim 8 in which the light-absorbing layer is substantially transparent at the interface, and in which a gradually increasing concentration of light-absorbing material is included as a function of the distance from said interface.

Claim 17

A luminescent device according to claim 10 in which the light-absorbing layer consists essentially of a silicon oxide at the interface.

Claim 18

A luminescent device according to claim 10 in which the light-absorbing layer consists essentially of a silicon oxide at the interface.

Claim 19

A luminescent device according to claim 11 in which the light-absorbing material includes aluminum.

Claim 20

A luminescent device according to claim 11 in which the light-absorbing material includes aluminum.

Claim 21

A luminescent device according to claim 8 in which a transparent electrode system is applied to the viewing side of the phosphor layer, and another electrode system on the opposite side of the light-absorbing layer from the viewing side.

Claim 22

A luminescent device according to claim 8 in which a transparent electrode system is applied to the viewing side of the phosphor layer, and another electrode system on the opposite side of the light-absorbing layer from the viewing side.