Patent US3809945A successfully refreshed from Google Patents.
US3809945A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shadow mask for color cathode ray tube and method of manufacture thereof
Assignee: Zenith Electronics LLC
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Filing: 1973-03-02
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Granted: 1974-05-07
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Expires: 1993-03-02
Abstract
Abstract This disclosure depicts novel aperture masks for rectangular color cathode ray tubes which are constructed such that hole enlargement, distortion or tearing which may be introduced in a mask-forming operation is minimized. In each embodiment depicted, a mask blank from which a mask is formed has an interior portion containing a pattern of electron-transmissive apertures, a peripheral portion adapted to be permanently deformed into a rigid mask skirt, and a transition structure between the interior and peripheral portions. The transition structure is caused to have a yield strength which is between that of the interior portions and said peripheral portion such that at least a part of the stretching forces and stretch deformation introduced in the mask-forming operation which would otherwise act upon and distort the aperture pattern in the interior portion of the mask is absorbed by the transition structure. In a preferred embodiment, the transition structure is provided by the formation of a plurality of additional rows of mask apertures etched part-waythrough on the periphery of the aperture pattern which cause the transition structure to have the said intermediate yield strength. Alternative transition structures and methods for fabricating masks as described are also depicted.
Inventors
- 👤 N Roeder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:57
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/06; H01J29/07; Y; Y10; Y10S; Y10S72/00; Y10S72/701
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
142 words
A mask blank to be formed into an aperture mask for masking electrons flowing to the screen of a color cathode ray tube, comprising a thin sheet of electrically conductive, permanently deformable material, said sheet having an interior portion of relatively low yield strength containing a predetermined pattern of electron-transmissive apertures, a peripheral portion which is adapted to be deformed in a mask-forming operation into a rigidifying skirt, and which has a relatively high yield strength, and a transition structure between said interior and peripheral portions of yield strength intermediate that of said interior portion and said peripheral portion, said transition structure at least partially circumscribing said interior portion to absorb at least a part of the stretching forces and stretch deformation introduced in the mask-forming operation which would otherwise act upon and distort said interior portion and thus said aperture pattern.
Claim 2
Dependent Claim
142 words
A mask blank to be formed into an aperture mask for masking electrons flowing to the screen of a color cathode ray tube, comprising a thin sheet of electrically conductive, permanently deformable material, said sheet having an interior portion of relatively low yield strength containing a predetermined pattern of electron-transmissive apertures, a peripheral portion which is adapted to be deformed in a mask-forming operation into a rigidifying skirt, and which has a relatively high yield strength, and a transition structure between said interior and peripheral portions of yield strength intermediate that of said interior portion and said peripheral portion, said transition structure at least partially circumscribing said interior portion to absorb at least a part of the stretching forces and stretch deformation introduced in the mask-forming operation which would otherwise act upon and distort said interior portion and thus said aperture pattern.
Claim 3
Dependent Claim
20 words
The blank defined by claim 1 wherein said sheet comprises a one-piece member having said transition structure formed integrally therein.
Claim 4
Dependent Claim
25 words
The blank defined by claim 2 wherein said sheet is thinned in said transition structure to cause said zone to have said intermediate yield strength.
Claim 5
Dependent Claim
31 words
The blank defined by Claim 2 wherein said blank has material removed therefrom in predetermined areas in said transition structure to cause said transition structure to have said intermediate yield strength.
Claim 6
Dependent Claim
21 words
The blank defined by claim 4 wherein said transition structure represents a plurality of rows of apertures etched only part-way through.
Claim 7
Dependent Claim
134 words
An aperture mask for masking electrons flowing to the screen of a color cathode ray tube, comprising a thin sheet of electrically conductive, permanently deformable material, said sheet having an interior portion having relatively low yield strength and containing a predetermined pattern of electron-transmissive apertures, a peripheral portion having a relatively high yield strength formed in a mask-forming operation to assume the shape of a rigidifying skirt, and having transition structure between said interior and peripheral portions of yield strength intermediate that of said interior portion and said peripheral portion, said transition structure at least partially circumscribing said interior portion and absorbing at least a part of the stretching forces and stretch deformation introduced in the mask-forming operation which would otherwise have acted upon and distorted said interior portion and thus said aperture pattern.
Claim 8
Dependent Claim
134 words
An aperture mask for masking electrons flowing to the screen of a color cathode ray tube, comprising a thin sheet of electrically conductive, permanently deformable material, said sheet having an interior portion having relatively low yield strength and containing a predetermined pattern of electron-transmissive apertures, a peripheral portion having a relatively high yield strength formed in a mask-forming operation to assume the shape of a rigidifying skirt, and having transition structure between said interior and peripheral portions of yield strength intermediate that of said interior portion and said peripheral portion, said transition structure at least partially circumscribing said interior portion and absorbing at least a part of the stretching forces and stretch deformation introduced in the mask-forming operation which would otherwise have acted upon and distorted said interior portion and thus said aperture pattern.
Claim 9
Dependent Claim
20 words
The mask defined by claim 6 wherein said sheet comprises a one-piece member having said transition structure formed integrally therein.
Claim 10
Dependent Claim
25 words
The mask defined by claim 7 wherein said sheet is thinned in said transition structure to cause said zone to have said intermediate yield strength.
Claim 11
Dependent Claim
28 words
The mask defined by claim 7 having material removed therefrom in predetermined areas in said transition structure to cause said transition structure to have said intermediate yield strength.
Claim 12
Dependent Claim
29 words
The mask defined by claim 9 wherein said predetermined areas represent an extension of the aperture pattern and constitute areas in which the sheet has been etched part-way through.
Claim 13
Independent Claim
176 words
A method of forming an aperture mask for masking electrons flowing to the screen of a color cathode ray tube, comprising: preparing a mask blank in the form of a sheet having an interior portion of relatively low yield strength containing a predetermined aperture pattern of electron-transmissive apertures and a peripheral portion surrounding said interior portion having a relatively high yield strength and being adapted to be deformed into a rigidifying skirt; and permanently deforming the blank out of the plane of said sheet in at least said peripheral portion to form a mask having a rigidifying skirt, said method being characterized by providing in said blank during said preparing step a transition structure between said interior and peripheral portions, of yield strength intermediate that of said interior portion and said peripheral portion, said transition structure at least partially circumscribing said interior portion to absorb at least a part of the stretching forces and stretch deformation introduced in the mask-forming operation which would otherwise act upon and distort said interior portion and thus said aperture pattern.
Claim 14
Independent Claim
176 words
A method of forming an aperture mask for masking electrons flowing to the screen of a color cathode ray tube, comprising: preparing a mask blank in the form of a sheet having an interior portion of relatively low yield strength containing a predetermined aperture pattern of electron-transmissive apertures and a peripheral portion surrounding said interior portion having a relatively high yield strength and being adapted to be deformed into a rigidifying skirt; and permanently deforming the blank out of the plane of said sheet in at least said peripheral portion to form a mask having a rigidifying skirt, said method being characterized by providing in said blank during said preparing step a transition structure between said interior and peripheral portions, of yield strength intermediate that of said interior portion and said peripheral portion, said transition structure at least partially circumscribing said interior portion to absorb at least a part of the stretching forces and stretch deformation introduced in the mask-forming operation which would otherwise act upon and distort said interior portion and thus said aperture pattern.
Claim 15
Dependent Claim
49 words
The method defined by claim 11 wherein said transition structure is provided by forming a transition structure stencil pattern on said blank during said preparing step and etching said blank through said transition zone stencil pattern to thin said blank in areas corresponding to said transition structure stencil pattern.
Claim 16
Independent Claim
241 words
A method of forming an aperture mask for masking electrons flowing to the secreen of a color cathode ray tube, comprising: preparing a mask blank from a thin sheet of an electrically conductive, permanently deformable, etchable material by forming on opposite sides of the blank is an interior portion thereof, registered, etch-resistant aperture stencil patterns corresponding in geometry to the aperture pattern desired for the mask, the electron stencil pattern on one side having a transition structure stencil pattern extending outwardly from the aperture stencil pattErn into a transition portion disposed intermediate said interior portion and a peripheral portion of the blank; etching the blank from both sides such that in said interior portion a pattern of through holes corresponding to the aperture stencil patterns are formed in the blank, whereas in said transition portion the blank is etched from one side only and only part-way through so as to form a transition structure in the blank having a yield strength which is intermediate that of the interior portion after etching and said peripheral portion of the blank; and permanently deforming the blank out of the plane of the sheet in said peripheral portion to form a mask having a rigidifying skirt, whereby said transition structure absorbs at least a part of the stretching forces and stretch deformation introduced in the mask-forming operation which would otherwise act upon and distort the interior portion of the mask and thus said aperture pattern.
Claim 17
Independent Claim
241 words
A method of forming an aperture mask for masking electrons flowing to the secreen of a color cathode ray tube, comprising: preparing a mask blank from a thin sheet of an electrically conductive, permanently deformable, etchable material by forming on opposite sides of the blank is an interior portion thereof, registered, etch-resistant aperture stencil patterns corresponding in geometry to the aperture pattern desired for the mask, the electron stencil pattern on one side having a transition structure stencil pattern extending outwardly from the aperture stencil pattErn into a transition portion disposed intermediate said interior portion and a peripheral portion of the blank; etching the blank from both sides such that in said interior portion a pattern of through holes corresponding to the aperture stencil patterns are formed in the blank, whereas in said transition portion the blank is etched from one side only and only part-way through so as to form a transition structure in the blank having a yield strength which is intermediate that of the interior portion after etching and said peripheral portion of the blank; and permanently deforming the blank out of the plane of the sheet in said peripheral portion to form a mask having a rigidifying skirt, whereby said transition structure absorbs at least a part of the stretching forces and stretch deformation introduced in the mask-forming operation which would otherwise act upon and distort the interior portion of the mask and thus said aperture pattern.
Claim 18
Dependent Claim
54 words
The method defined by claim 13 wherein the mask is a shadow mask of the type used with dot triad type color cathode ray tube screen, and wherein said transition structure stencil pattern constitutes an extension for a number of rows of the aperture stencil pattern on the said one side of the blank.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-06 | 1977-11-05 | 1978-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-06 | 1981-11-05 | 1982-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-06 | 1985-11-05 | 1986-05-07 | $7700.00 | Window Closed / Lapsed |