Fluorescent screens of color picture tubes and manufacturing method therefor

Claim 1

In a method of manufacturing color picture tubes which tubes include a panel the inner surface of which is coated with a pattern of a black matrix layer and a pattern of a fine dot light absorptive layer of a non-luminous light absorption substance, and a reflective layer on said fine dot light absorptive layer, said black matrix layer, said light absorptive layer, and said reflective layer being overlaid with fluorescent material to form a fluorescent screen for said color tube, which method comprises the steps of: forming on the inner surface of said panel a photosensitive resin layer which becomes sticky upon exposure to light; mounting a photomask on the outside of said panel; exposing to light said photosensitive resin layer through at least the photomask to form a pattern of sticky portions of said resin layer at which a fine dot pattern of said light absorption layer is to be formed, and whereby the portion of the resin layer not being exposed to light will not be made sticky; applying said non-luminous light absorbing substance or a substance convertible thereto on said photosensitive resin layer and developing with air to form a pattern of said light absorbing layer corresponding to the pattern of said sticky portions of said resin layer; delaying performance of the next step long enough for some of said sticky substance to ooze through the pattern of said light absorbing layer to the surface of said light absorbing substance; spraying a fine powder of white material on the surfaces of the pattern of said light absorbing layer where said sticky substance has oozed through and developing said surfaces with air to form a fine dot pattern of said light absorbing layer on the surface of which a light reflection layer is deposited.

Claim 4

A method of manufacturing a fluorescent screen for a black matrix type color picture tube wherein said tube includes a panel, a pattern of a black matrix layer formed on the inner surface of said panel, the pattern of said black matrix layer having windows where a layer of phosphor powder of respective kinds of color is to be formed, a pattern of an additional light absorbing layer being formed within said windows, and a light reflecting layer being formed on both the pattern of said black matrix layer and the pattern of said additional light absorbing layer, said method comprising the steps of: (A) forming a photosensitive resin layer which becomes sticky upon exposure to light on the inner surface of said panel; (B) mounting a shadow mask on the inside of said panel; (C) exposing said photosensitive resin to light from an internal light source through the shadow mask to form a pattern of sticky portions of said resin layer at which said black matrix pattern layer will be formed and leaving windows in said black matrix pattern layer where said resin is not exposed to light; (D) exposing to light, from an external light source, portions of said windows left in said sticky portions, said exposure being through a photomask mounted on the outside of said panel to form a further pattern of sticky portions of said resin layer in said windows at which said additional light absorbing pattern layer is to be formed within the respective windows in the black matrix pattern; (E) removing the internal shadow mask; (F) applying a non-luminous absorbing substance or a substance convertible thereto on said pattern of sticky portions and said further pattern of sticky portions to form said pattern of said black matrix layer and a pattern of said additional light absorbing layer, respectively; (G) delaying performance of the next step long enough for some of the sticky photosensitive resin to ooze through said light-absorbing substance to the surface thereof; (H) applying a fine powder of white material on the surfaces of said black matrix and additional light-absorbing pattern layers where said sticky photosensitive resin has oozed through and developing said layers by air to form the light reflection layers; (I) mounting again the shadow mask; (J) exposing to light from the internal light source said photosensitive resin layer through said shadow mask to form a pattern of sticky portions of said resin layer at which a phosphor powder layer is to be deposited within the respective windows in the black matrix pattern; (K) removing again said shadow mask; (L) applying a phosphor powder over the photosensitive resin layer to form the phosphor powder layer within the respective windows.

Claim 5

A method of manufacturing a fluorescent screen for a black matrix type color picture tube wherein said tube includes a panel, a pattern of a black matrix layer formed on the inner surface of said panel, the pattern of said black matrix layer having windows where a layer of phosphor powder of respective kinds of color is to be formed, a pattern of an additional light absorbing layer being formed within said windows, and a light reflecting layer being formed on both the pattern of said black matrix layer and the pattern of said additional light absorbing layer, said method comprising the steps of: (A) forming a photosensitive resin layer which becomes sticky upon exposure to light on the inner surface of said panel; (B) mounting a shadow mask on the inside of said panel; (C) exposing said photosensitive resin to light from an internal light source through the shadow mask to form a pattern of sticky portions of said resin layer at which said black matrix pattern layer will be formed and leaving windows in said black matrix pattern layer where said resin is not exposed to light; (D) exposing to light, from an external light source, portions of said windows left in said sticky portions, said exposure being through a photomask mounted on the outside of said panel to form a further pattern of sticky portions of said resin layer in said windows at which said additional light absorbing pattern layer is to be formed within the respective windows in the black matrix pattern; (E) removing the internal shadow mask; (F) applying a non-luminous absorbing substance or a substance convertible thereto on said pattern of sticky portions and said further pattern of sticky portions to form said pattern of said black matrix layer and a pattern of said additional light absorbing layer, respectively; (G) delaying performance of the next step long enough for some of the sticky photosensitive resin to ooze through said light-absorbing substance to the surface thereof; (H) applying a fine powder of white material on the surfaces of said black matrix and additional light-absorbing pattern layers where said sticky photosensitive resin has oozed through and developing said layers by air to form the light reflection layers; (I) mounting again the shadow mask; (J) exposing to light from the internal light source said photosensitive resin layer through said shadow mask to form a pattern of sticky portions of said resin layer at which a phosphor powder layer is to be deposited within the respective windows in the black matrix pattern; (K) removing again said shadow mask; (L) applying a phosphor powder over the photosensitive resin layer to form the phosphor powder layer within the respective windows.