Manufacture of shadow mask color picture tube

Claim 2

In the manufacture of a shadow-mask type of color cathode-ray tube having a face panel section, the improvement which includes the following steps: forming a mask-frame component comprising an imperforate mask portion of a material subject to etching configured to correspond substantially to the internal surface of said face panel section of the tube in process and further comprising a frame portion extending from said mask portion for securing the mask-frame component in a predetermined position within said face panel section; applying to at least one surface of said mask portion a coating of a sensitized resist; supporting said mask-frame component in predetermined alignment with reference to a first master having a predetermined pattern of transparent portions by an arrangement establishing at least six points of coupling between said mask-frame and said master to suppOrt said mask-frame and said master with their geometric centers aligned along a common reference axis; exposing said coating to actinic energy through said master to establish in said coating a latent image of a desired aperture pattern; developing said image and thereafter etching said mask portion to create therein said aperture pattern; and producing a screened face panel from a screening master having a predetermined relationship to said first master so that any aperture mask processed from said first master is utilizable with any face panel processed from said screening master.

Claim 3

The improvement in accordance with claim 1 in which said mask portion and said frame portion are separately formed; and said mask portion is stress relieved and then is united with said frame portion.

Claim 4

The improvement in accordance with claim 2 in which said mask-frame component is further stress relieved after said mask portion and said frame portion have been united to one another.

Claim 5

The improvement in accordance with claim 3 in which said mask portion and said frame portion are oxidized prior to the application of said resist coating; and in which said mask is treated with an oxide stripper subsequent to said development step but prior to said etching step.

Claim 6

The improvement in accordance with claim 3 in which said frame portion is provided with leaf mounting springs and is stress relieved before being united with said mask portion.

Claim 7

The improvement in accordance with claim 1 in which a coating of said sensitized resist is applied to both surfaces of said mask portion; said mask-frame component is supported in predetermined alignment with a pair of first masters positioned on opposite sides of said mask-frame component; both coatings of resist are exposed through said pair of masters, respectively to establish said latent image; said mask portion is etched from both sides to create said aperture pattern; and said screening master has a predetermined relationship to one of said first masters.

Claim 8

The improvement in accordance with claim 6 in which said predetermined alignment is established by six point coupling arrangements which support said mask-frame component and both of said masters with their geometric centers aligned along a common reference axis.

Claim 9

The improvement in accordance with claim 7 in which said pair of masters is formed by a photoprinting process in which: a. a bogey mask-frame is positioned in said predetermined alignment between a pair of substrates having sensitized surfaces facing said bogey mask-frame and (b) both of said surfaces are exposed to actinic energy directed thereto through said bogey mask frame.

Claim 10

The improvement in accordance with claim 1 which includes the following additional steps: developing said screening master to have a preselected relationship to said first master through which said exposure step of said mask-frame takes place; supporting said face panel referenced to said screening master in accordance with said predetermined alignment of said mask-frame component in relation to said first master; and screening on said face panel a phosphor pattern determined by exposing said panel through said screening master.

Claim 11

The improvement in accordance with claim 9 in which said screening master is derived from the same bogey mask-frame used in developing said first master.

Claim 12

The improvement in accordance with claim 10 in which said aperture pattern of said mask-frame is a multiplicity of substantially circular holes distributed over a generally rectangular field; in which a family of three screening masters are developed from said bogey mask-frame, one for screening with each of green, blue and red emitting phosphors; and in which said face panel is successively screened with each of said three screening masters to form a phosphor-dot triad screen on said panel.

Claim 13

The improvement in accordance with claim 11 in which said mask-frame compOnent is installed within said face panel only after said panel has been screened through said three screening masters.

Claim 14

The improvement in accordance with claim 11 in which the screening of said face panel with any of said phosphors includes the step of removably supporting said panel in an exposure chamber in which the one of said screening masters associated with the phosphor being screened is permanently installed; and in which said panel is referenced to said screening master in the manner in which said mask-frame component is referenced to its master during the exposure of said mask portion.

Claim 15

The improvement in accordance with claim 13 in which said screening master is derived from said bogey mask-frame through a process which incorporates correction factors in the pattern of said screen master which may be projected directly on said panel, without the imposition of a correcting lens, in the exposure of said panel.

Claim 16

In the manufacture of a shadow mask color tube, the improvements which includes the following steps: forming a mask-frame having a mask portion of a material subject to attack by an etchant and characterized by the fact that the mask is a formed imperforate blank; coating said mask with a sensitized resist; supporting said mask-frame by an arrangement establishing at least six points of coupling between said mask-frame and a fixture with the geometric center of said mask disposed along a first reference axis; similarly supporting a first master, representing the aperture pattern of a bogey mask-frame, by an arrangement establishing at least six points of coupling between said first master and said fixture with the geometric center of said first master on said first reference axis; exposing said mask to actinic energy through said first master to create a latent image of an aperture pattern in said coating; developing said latent image and then etching said mask to create said aperture pattern therein; screening the face panel of said tube by: a. coating the internal surface of the face panel with a sensitized resist; b. supporting said panel by an arrangement establishing at least six points of coupling between said panel and another fixture so that the geometric center of said panel is disposed along a second reference axis; c. similarly supporting a screening master, also representing the aperture pattern of said bogey mask-frame, by an arrangement establishing at least six points of coupling between said screening master and said other fixture with the geometric center of said screening master on said second reference axis, said second axis being equivalent to said first axis in that said first master and said screening master are both referenced to said bogey mask-frame; and d. applying to said panel a phosphor pattern determined by exposing said panel to actinic energy through said screening master; and finally installing said mask-frame in said panel.

Claim 17

In the manufacture of a shadow mask color tube, the improvements which includes the following steps: forming a mask-frame having a mask portion of a material subject to attack by an etchant and characterized by the fact that the mask is a formed imperforate blank; coating said mask with a sensitized resist; supporting said mask-frame by an arrangement establishing at least six points of coupling between said mask-frame and a fixture with the geometric center of said mask disposed along a first reference axis; similarly supporting a first master, representing the aperture pattern of a bogey mask-frame, by an arrangement establishing at least six points of coupling between said first master and said fixture with the geometric center of said first master on said first reference axis; exposing said mask to actinic energy through said first master to create a latent image of an aperture pattern in said coating; developing said latent image and then etching said mask to create said aperture pattern therein; screening the face panel of said tube by: a. coating the internal surface of the face panel with a sensitized resist; b. supporting said panel by an arrangement establishing at least six points of coupling between said panel and another fixture so that the geometric center of said panel is disposed along a second reference axis; c. similarly supporting a screening master, also representing the aperture pattern of said bogey mask-frame, by an arrangement establishing at least six points of coupling between said screening master and said other fixture with the geometric center of said screening master on said second reference axis, said second axis being equivalent to said first axis in that said first master and said screening master are both referenced to said bogey mask-frame; and d. applying to said panel a phosphor pattern determined by exposing said panel to actinic energy through said screening master; and finally installing said mask-frame in said panel.

Claim 18

The improvement in accordance with claim 15 in which both surfaces of said mask are coated with said resist; a second master is supported as said first master but on the opposite side of said mask; both surfaces of said mask are exposed through said first and second masters, respectively, to create said latent image; and said panel is screened with green, blue and red emitting phosphors through repeating said steps (a) - (d) three times but each time utilizing a screening master derived from said bogey mask frame and individual to an assigned one of said phosphors.

Claim 19

The improvement in accordance with claim 15 in which said mask-frame is stress relieved before being exposed to actinic energy.